Mortality assessment attributed to long-term exposure to fine particles in ambient air of the megacity of Tehran, Iran.

PubMed

Yarahmadi, Maryam; Hadei, Mostafa; Nazari, Seyed Saeed Hashemi; Conti, Gea Oliveri; Alipour, Mohammd Reza; Ferrante, Margherita; Shahsavani, Abbas

2018-05-01

Few studies regarding the health effects of long-term exposure to particulate matter with an aerodynamic diameter of 2.5 μm or less (PM 2.5 ) have been carried out in Asia or the Middle East. The objective of our study was to assess total, lung cancer and chronic obstructive pulmonary disease (COPD) mortality attributed to long-term exposure to PM 2.5 among adults aged over 30 years in Tehran from March 2013 to March 2016 using AirQ + software. AirQ + modeling software was used to estimate the number of deaths attributed to PM 2.5 concentrations higher than 10 μg m -3 . Air quality data were obtained from the Department of Environment (DOE) and Tehran Air Quality Control Company (TAQCC). Only valid stations with data completeness of 75% in all 3 years were selected for entry into the model. The 3-year average of the 24-h concentrations was 39.17 μg m -3 . The results showed that the annual average concentration of PM 2.5 in 2015-2016 was reduced by 13% compared to that in 2013-2014. The annual average number of all natural, COPD, and lung cancer deaths attributable to long-term exposure to PM 2.5 in adults aged more than 30 years was 5073, 158, and 142 cases, respectively. The results of all three health endpoints indicate that the mortality attributable to PM 2.5 decreased yearly from 2013 to 2016 and that the reduced mortality was related to a corresponding reduction in the PM 2.5 concentration. Considering these first positive results, the steps that have been currently taken for reducing air pollution in Tehran should be continued to further improve the already positive effects of these measures on reducing health outcomes.

Residence times in river basins as determined by analysis of long-term tritium records

USGS Publications Warehouse

Michel, R.L.

1992-01-01

The US Geological Survey has maintained a network of stations to collect samples for the measurement of tritium concentrations in precipitation and streamflow since the early 1960s. Tritium data from outflow waters of river basins draining 4500-75000 km2 are used to determine average residence times of water within the basins. The basins studied are the Colorado River above Cisco, Utah; the Kissimmee River above Lake Okeechobee, Florida; the Mississippi River above Anoka, Minnesota; the Neuse River above Streets Ferry Bridge near Vanceboro, North Carolina; the Potomac River above Point of Rocks, Maryland; the Sacramento River above Sacramento, California; the Susquehanna River above Harrisburg, Pennsylvania. The basins are modeled with the assumption that the outflow in the river comes from two sources-prompt (within-year) runoff from precipitation, and flow from the long-term reservoirs of the basin. Tritium concentration in the outflow water of the basin is dependent on three factors: (1) tritium concentration in runoff from the long-term reservoir, which depends on the residence time for the reservoir and historical tritium concentrations in precipitation; (2) tritium concentrations in precipitation (the within-year runoff component); (3) relative contributions of flow from the long-term and within-year components. Predicted tritium concentrations for the outflow water in the river basins were calculated for different residence times and for different relative contributions from the two reservoirs. A box model was used to calculate tritium concentrations in the long-term reservoir. Calculated values of outflow tritium concentrations for the basin were regressed against the measured data to obtain a slope as close as possible to 1. These regressions assumed an intercept of zero and were carried out for different values of residence time and reservoir contribution to maximize the fit of modeled versus actual data for all the above rivers. The final slopes of the fitted regression lines ranged from 0.95 to 1.01 (correlation coefficient > 0.96) for the basins studied. Values for the residence time of waters within the basins and average relative contributions of the within-year and long-term reservoirs to outflow were obtained. Values for river basin residence times ranged from 2 years for the Kissimmee River basin to 20 years for the Potomac River basin. The residence times indicate the time scale in which the basin responds to anthropogenic inputs. The modeled tritium concentrations for the basins also furnish input data for urban and agricultural settings where these river waters are used. ?? 1992.

Long-term dynamics of chlorophyll concentration in the ocean surface layer (by space data)

NASA Astrophysics Data System (ADS)

Shevyrnogov, A.; Vysotskaya, G.

To preserve the biosphere and to use it efficiently, it is necessary to gain a deep insight into the dynamics of the primary production process on our planet. Variability of chlorophyll concentration in the ocean is one of the most important components of this process. These investigations are, however, very labor-consuming, because of the difficulties related to the accessibility of the water surface and its large size. In this work long-term changes in chlorophyll concentration in the surface layer of the ocean have been analyzed on the basis of the CZCS data for 7.5 years from 1979 to 1986 and the SeaWiFS data from 1997 to 2004. It has been shown that the average chlorophyll concentration calculated in all investigated areas varies moderately. However, when analyzing spatially local trends, the areas have been detected that have significant rise and fall of chlorophyll concentrations. Some interesting features of the long-term dynamics of chlorophyll concentration have been found. The opposite directions of long-term trends (essential increase or decrease) cannot be explained only by large-scale hydrological phenomena in the ocean (currents, upwellings, etc.). The measured chlorophyll concentration results from the balance between production and destruction processes. Which process dominates is determined by various hydrophysical, hydrobiological, and climatic processes, leading to sharp rises or falls of the concentration. It is important to estimate the scale of the areas in which this or that process dominates. Therefore, the study addresses not only the dynamics of the mean value but also the dynamics of the areas in which the dominance of certain factors has led to a sharp fall or rise in chlorophyll concentration. Thus, the obtained results can be used to estimate long-term changes in the ocean biota.

Study of dissolved oxygen content in the Eastern Bosporus Strait (Peter the Great Bay, Sea of Japan)

NASA Astrophysics Data System (ADS)

Grigoryeva, N. I.

2017-09-01

Seasonal changes in the dissolved oxygen (DO) content in water were analyzed based on long-term observations (2006-2013) in the Eastern Bosporus Strait (Peter the Great Bay, Sea of Japan). It was found that the monthly average DO concentrations at the bottom of the strait were significantly lower in summer than the average annual long-term data. The minimum DO contents were recorded during four months, from July to October. It was shown that the DO content in water depended on changes in current directions in the strait: lower DO contents resulted from hypoxic water inflow, mostly from Amur Bay.

Meteorological detrending of primary and secondary pollutant concentrations: Method application and evaluation using long-term (2000-2012) data in Atlanta

NASA Astrophysics Data System (ADS)

Henneman, Lucas R. F.; Holmes, Heather A.; Mulholland, James A.; Russell, Armistead G.

2015-10-01

The effectiveness of air pollution regulations and controls are evaluated based on measured air pollutant concentrations. Air pollution levels, however, are highly sensitive to both emissions and meteorological fluctuations. Therefore, an assessment of the change in air pollutant levels due to emissions controls must account for these meteorological fluctuations. Two empirical methods to quantify the impact of meteorology on pollutant levels are discussed and applied to the 13-year time period between 2000 and 2012 in Atlanta, GA. The methods employ Kolmogorov-Zurbenko filters and linear regressions to detrended pollutant signals into long-term, seasonal, weekly, short-term, and white-noise components. The methods differ in how changes in weekly and holiday emissions are accounted for. Both can provide meteorological adjustments on a daily basis for future use in acute health analyses. The meteorological impact on daily signals of ozone, NOx, CO, SO2, PM2.5, and PM species are quantified. Analyses show that the substantial decreases in seasonal averages of NOx and SO2 correspond with controls implemented in the metropolitan Atlanta area. Detrending allows for the impacts of some controls to be observed with averaging times of as little as 3 months. Annual average concentrations of NOx, SO2, and CO have all fallen by at least 50% since 2000. Reductions in NOx levels, however, do not lead to uniform reductions in ozone. While average detrended summer average maximum daily average 8 h ozone (MDA8h O3) levels fell by 4% (2.2 ± 2 ppb) between 2000 and 2012, winter averages have increased by 12% (3.8 ± 1.4 ppb), providing further evidence that high ozone levels are NOx-limited and lower ozone concentrations are NOx-inhibited. High ozone days (with MDA8h O3 greater than 60 ppb) decreased both in number and in magnitude over the study period.

An integrated Bayesian model for estimating the long-term health effects of air pollution by fusing modelled and measured pollution data: A case study of nitrogen dioxide concentrations in Scotland.

PubMed

Huang, Guowen; Lee, Duncan; Scott, Marian

2015-01-01

The long-term health effects of air pollution can be estimated using a spatio-temporal ecological study, where the disease data are counts of hospital admissions from populations in small areal units at yearly intervals. Spatially representative pollution concentrations for each areal unit are typically estimated by applying Kriging to data from a sparse monitoring network, or by computing averages over grid level concentrations from an atmospheric dispersion model. We propose a novel fusion model for estimating spatially aggregated pollution concentrations using both the modelled and monitored data, and relate these concentrations to respiratory disease in a new study in Scotland between 2007 and 2011. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Worldwide impact of aerosol's time scale on the predicted long-term concentrating solar power potential.

PubMed

Ruiz-Arias, Jose A; Gueymard, Christian A; Santos-Alamillos, Francisco J; Pozo-Vázquez, David

2016-08-10

Concentrating solar technologies, which are fuelled by the direct normal component of solar irradiance (DNI), are among the most promising solar technologies. Currently, the state-of the-art methods for DNI evaluation use datasets of aerosol optical depth (AOD) with only coarse (typically monthly) temporal resolution. Using daily AOD data from both site-specific observations at ground stations as well as gridded model estimates, a methodology is developed to evaluate how the calculated long-term DNI resource is affected by using AOD data averaged over periods from 1 to 30 days. It is demonstrated here that the use of monthly representations of AOD leads to systematic underestimations of the predicted long-term DNI up to 10% in some areas with high solar resource, which may result in detrimental consequences for the bankability of concentrating solar power projects. Recommendations for the use of either daily or monthly AOD data are provided on a geographical basis.

Worldwide impact of aerosol’s time scale on the predicted long-term concentrating solar power potential

PubMed Central

Ruiz-Arias, Jose A.; Gueymard, Christian A.; Santos-Alamillos, Francisco J.; Pozo-Vázquez, David

2016-01-01

Concentrating solar technologies, which are fuelled by the direct normal component of solar irradiance (DNI), are among the most promising solar technologies. Currently, the state-of the-art methods for DNI evaluation use datasets of aerosol optical depth (AOD) with only coarse (typically monthly) temporal resolution. Using daily AOD data from both site-specific observations at ground stations as well as gridded model estimates, a methodology is developed to evaluate how the calculated long-term DNI resource is affected by using AOD data averaged over periods from 1 to 30 days. It is demonstrated here that the use of monthly representations of AOD leads to systematic underestimations of the predicted long-term DNI up to 10% in some areas with high solar resource, which may result in detrimental consequences for the bankability of concentrating solar power projects. Recommendations for the use of either daily or monthly AOD data are provided on a geographical basis. PMID:27507711

[A comparative evaluation of the methods for determining nitrogen dioxide in an industrial environment].

PubMed

Panev, T

1991-01-01

The present work has the purpose to make a comparative evaluation of the different types detector tubes--for analysis, long-term and passive for determination of NO2 and the results to be compared, with those received by the spectrophotometric method and the reagent of Zaltsman. Studies were performed in the hall of the garage for repair of diesel buses during one working shift. The results point out that the analysing tubes for NO2 give good results with the spectrophotometric method. The measured average-shift concentrations of NO2 by long-term and passive tubes are juxtaposed with the average-received values with the analytical tubes and with the analytical method.

Long-term changes in lower tropospheric baseline ozone concentrations: Comparing chemistry-climate models and observations at northern midlatitudes

NASA Astrophysics Data System (ADS)

Parrish, D. D.; Lamarque, J.-F.; Naik, V.; Horowitz, L.; Shindell, D. T.; Staehelin, J.; Derwent, R.; Cooper, O. R.; Tanimoto, H.; Volz-Thomas, A.; Gilge, S.; Scheel, H.-E.; Steinbacher, M.; Fröhlich, M.

2014-05-01

Two recent papers have quantified long-term ozone (O3) changes observed at northern midlatitude sites that are believed to represent baseline (here understood as representative of continental to hemispheric scales) conditions. Three chemistry-climate models (NCAR CAM-chem, GFDL-CM3, and GISS-E2-R) have calculated retrospective tropospheric O3 concentrations as part of the Atmospheric Chemistry and Climate Model Intercomparison Project and Coupled Model Intercomparison Project Phase 5 model intercomparisons. We present an approach for quantitative comparisons of model results with measurements for seasonally averaged O3 concentrations. There is considerable qualitative agreement between the measurements and the models, but there are also substantial and consistent quantitative disagreements. Most notably, models (1) overestimate absolute O3 mixing ratios, on average by 5 to 17 ppbv in the year 2000, (2) capture only 50% of O3 changes observed over the past five to six decades, and little of observed seasonal differences, and (3) capture 25 to 45% of the rate of change of the long-term changes. These disagreements are significant enough to indicate that only limited confidence can be placed on estimates of present-day radiative forcing of tropospheric O3 derived from modeled historic concentration changes and on predicted future O3 concentrations. Evidently our understanding of tropospheric O3, or the incorporation of chemistry and transport processes into current chemical climate models, is incomplete. Modeled O3 trends approximately parallel estimated trends in anthropogenic emissions of NOx, an important O3 precursor, while measured O3 changes increase more rapidly than these emission estimates.

Major floods, poor land use delay return of sedimentation to normal rates

Treesearch

Henry W. Anderson

1972-01-01

Recovery from flood-accelerated sedimentation affects both estimates of long-term average deposition and short-term monitoring of changes. "Years to return to normal" for 10 watersheds in northern California after a major flood accelerated sediment concentrations were analyzed. Returns to normalcy took from 0 to 9 years; rate of decline was related to both...

Changes in stream nitrate concentrations due to land management practices, ecological succession, and climate: Developing a system approach to integrated catchment response

Treesearch

F. Worrall; Wayne T. Swank; T. P. Burt

2003-01-01

This study uses time series analysis to examine long-term stream water nitrate concentration records from a pair of forested catchments at the Coweeta Hydrologic Laboratory, North Carolina, USA. Monthly average concentrations were available from 1970 through 1997 for two forested catchments, one of which was clear-felled in 1977 and the other maintained as a control....

Evaluation of a long-term operation of a submerged nanofiltration membrane bioreactor (NF MBR) for advanced wastewater treatment.

PubMed

Choi, J H; Fukushi, K; Ng, H Y; Yamamoto, K

2006-01-01

Nanofiltration (NF) is considered as one of the most promising separation technologies to obtain a very good-quality permeate in water and wastewater treatment. A submerged NF membrane bioreactor (NF MBR) using polyamide membranes was tested for a long-term operation and the performance of the NF MBR was compared with that of a microfiltration MBR (MF MBR). Total organic carbon (TOC) concentration in the permeate of the NF MBR ranged from 0.5 to 2.0 mg/L, whereas that of the MF MBR showed an average of 5 mg/L. This could be explained by the tightness of the NF membrane. Although the concentration of organic matter in the supernatant of the NF MBR was higher than that in the permeate due to high rejection by the NF membrane, the NF MBR showed excellent treatment efficiency and satisfactory operational stability for a long-term operation.

Long-term erosion rates of Panamanian drainage basins determined using in situ 10Be

NASA Astrophysics Data System (ADS)

Gonzalez, Veronica Sosa; Bierman, Paul R.; Nichols, Kyle K.; Rood, Dylan H.

2016-12-01

Erosion rates of tropical landscapes are poorly known. Using measurements of in situ-produced 10Be in quartz extracted from river and landslide sediment samples, we calculate long-term erosion rates for many physiographic regions of Panama. We collected river sediment samples from a wide variety of watersheds (n = 35), and then quantified 24 landscape-scale variables (physiographic, climatic, seismic, geologic, and land-use proxies) for each watershed before determining the relationship between these variables and long-term erosion rates using linear regression, multiple regression, and analysis of variance (ANOVA). We also used grain-size-specific 10Be analysis to infer the effect of landslides on the concentration of 10Be in fluvial sediment and thus on erosion rates. Cosmogenic 10Be-inferred, background erosion rates in Panama range from 26 to 595 m My- 1, with an arithmetic average of 201 m My- 1, and an area-weighted average of 144 m My- 1. The strongest and most significant relationship in the dataset was between erosion rate and silicate weathering rate, the mass of material leaving the basin in solution. None of the topographic variables showed a significant relationship with erosion rate at the 95% significance level; we observed weak but significant correlation between erosion rates and several climatic variables related to precipitation and temperature. On average, erosion rates in Panama are higher than other cosmogenically-derived erosion rates in tropical climates including those from Puerto Rico, Madagascar, Australia and Sri Lanka, likely the result of Panama's active tectonic setting and thus high rates of seismicity and uplift. Contemporary sediment yield and cosmogenically-derived erosion rates for three of the rivers we studied are similar, suggesting that human activities are not increasing sediment yield above long-term erosion rate averages in Panama. 10Be concentration is inversely proportional to grain size in landslide and fluvial samples from Panama; finer grain sizes from landslide material have lower 10Be concentration than fine-grained fluvial sediment. Large grains from both landslide and stream sediments have similarly low 10Be concentrations. These data suggest that fluvial gravel is delivered to the channel by landslides whereas sand is preferentially delivered by soil creep and bank collapse. Furthermore, the difference in 10Be concentration in sand-sized material delivered by soil creep and that delivered by landsliding suggests that the frequency and intensity of landslides influence basin scale erosion rates.

Association between Long-Term Exposure to Particulate Matter Air Pollution and Mortality in a South Korean National Cohort: Comparison across Different Exposure Assessment Approaches

PubMed Central

Kim, Sun-Young; Kim, Ho

2017-01-01

Increasing numbers of cohort studies have reported that long-term exposure to ambient particulate matter is associated with mortality. However, there has been little evidence from Asian countries. We aimed to explore the association between long-term exposure to particulate matter with a diameter ≤10 µm (PM10) and mortality in South Korea, using a nationwide population-based cohort and an improved exposure assessment (EA) incorporating time-varying concentrations and residential addresses (EA1). We also compared the association across different EA approaches. We used information from 275,337 people who underwent health screening from 2002 to 2006 and who had follow-up data for 12 years in the National Health Insurance Service-National Sample Cohort. Individual exposures were computed as 5-year averages using predicted residential district-specific annual-average PM10 concentrations for 2002–2006. We estimated hazard ratios (HRs) of non-accidental and five cause-specific mortalities per 10 µg/m3 increase in PM10 using the Cox proportional hazards model. Then, we compared the association of EA1 with three other approaches based on time-varying concentrations and/or addresses: predictions in each year and addresses at baseline (EA2); predictions at baseline and addresses in each year (EA3); and predictions and addresses at baseline (EA4). We found a marginal association between long-term PM10 and non-accidental mortality. The HRs of five cause-specific mortalities were mostly higher than that of non-accidental mortality, but statistically insignificant. In the comparison between EA approaches, the HRs of EA1 were similar to those of EA2 but higher than EA3 and EA4. Our findings confirmed the association between long-term exposure to PM10 and mortality based on a population-representative cohort in South Korea, and suggested the importance of assessing individual exposure incorporating air pollution changes over time. PMID:28946613

Long-term exposure to residential ambient fine and coarse particulate matter and incident hypertension in post-menopausal women.

PubMed

Honda, Trenton; Eliot, Melissa N; Eaton, Charles B; Whitsel, Eric; Stewart, James D; Mu, Lina; Suh, Helen; Szpiro, Adam; Kaufman, Joel D; Vedal, Sverre; Wellenius, Gregory A

2017-08-01

Long-term exposure to ambient particulate matter (PM) has been previously linked with higher risk of cardiovascular events. This association may be mediated, at least partly, by increasing the risk of incident hypertension, a key determinant of cardiovascular risk. However, whether long-term exposure to PM is associated with incident hypertension remains unclear. Using national geostatistical models incorporating geographic covariates and spatial smoothing, we estimated annual average concentrations of residential fine (PM 2.5 ), respirable (PM 10 ), and course (PM 10-2.5 ) fractions of particulate matter among 44,255 post-menopausal women free of hypertension enrolled in the Women's Health Initiative (WHI) clinical trials. We used time-varying Cox proportional hazards models to evaluate the association between long-term average residential pollutant concentrations and incident hypertension, adjusting for potential confounding by sociodemographic factors, medical history, neighborhood socioeconomic measures, WHI study clinical site, clinical trial, and randomization arm. During 298,383 person-years of follow-up, 14,511 participants developed incident hypertension. The adjusted hazard ratios per interquartile range (IQR) increase in PM 2.5 , PM 10 , and PM 10-2.5 were 1.13 (95% CI: 1.08, 1.17), 1.06 (1.03, 1.10), and 1.01 (95% CI: 0.97, 1.04), respectively. Statistically significant concentration-response relationships were identified for PM 2.5 and PM 10 fractions. The association between PM 2.5 and hypertension was more pronounced among non-white participants and those residing in the Northeastern United States. In this cohort of post-menopausal women, ambient fine and respirable particulate matter exposures were associated with higher incidence rates of hypertension. These results suggest that particulate matter may be an important modifiable risk factor for hypertension. Copyright © 2017 Elsevier Ltd. All rights reserved.

Long-term trends of metal content and water quality in the Belaya River Basin

NASA Astrophysics Data System (ADS)

Fashchevskaia, Tatiana; Motovilov, Yuri

2017-04-01

The aim of this research is to identify the spatiotemporal regularities of iron, copper and zinc contents in the streams of the Belaya River basin. The Belaya River is situated in the South Ural region and it is one of the biggest tributary in the Volga River basin with catchment area of 142 000 km2. More than sixty years the diverse economic activities are carried out in the Belaya River basin, the intensity of this activity is characterized by high temporal variability. The leading industries in the region are metallurgy, oil production, petroleum processing, chemistry and petro chemistry, mechanical engineering, power industry. The dynamics of human activities in the catchment and intra and inter-annual changes in the water quality were analyzed for the period 1969-2007 years. Inter-annual dynamics of the metal content in the river waters was identified on the basis of the long-term hydrological monitoring statistics at the 32 sites. It was found that the dynamics of intensity of economic activities in the Belaya River basin was the cause statistically significant changes in the metal content of the river network. Statistically homogeneous time intervals have been set for each monitoring site. Within these time intervals there were obtained averaged reliable quantitative estimations of water quality. Calculations showed that the content of iron, copper and zinc did not change during the analyzed period at the sites, located in the mountain and foothill parts of the basin. At other sites, located on the plains areas of the Belaya River Basin and in the areas of functioning of large industrial facilities, metal content varies. A period of increased concentrations of metals is since the second half of 1970 until the end of the 1990s. From the end of 1990 to 2007 the average metal content for a long-term period in the river waters is reduced in comparison with the previous period: iron - to 7.4 times, copper - to 6.7 times, zinc - to 15 times. As a result, by the end of the test period the average long-term metal content in the river waters is: iron 0.07-1.21 mg/l, copper 0.9-7.0 μg/l, zinc 2,0-12.5 μg/l. Empirical probability distributions of iron, copper and zinc concentrations for various phases of the water regime in all investigated monitoring sites were approximated by Pearson type III curves and the average of the concentration values, the coefficient of variation and asymmetry, as well as the values of the concentrations of metal in the range of 1-95% of frequency were estimated. It was found that by the end of the test period, the average long-term concentrations for iron and copper exceed MAC for fishery use, for zinc become smaller MAC in many streams of Belaya River basin. The probability of exceeding the iron and copper content of MAC level increases during floods, the zinc content of MAC level increases during the winter low. Acknowledgements. The work was financially supported by the Russian Foundation for Basic Research (Grant 15-05-09022)

SIMULATING ATMOSPHERIC EXPOSURE IN A NATIONAL RISK ASSESSMENT USING AN INNOVATIVE METEOROLOGICAL SAMPLING SCHEME

EPA Science Inventory

Multimedia risk assessments require the temporal integration of atmospheric concentration and deposition with other media modules. However, providing an extended time series of estimates is computationally expensive. An alternative approach is to substitute long-term average a...

Potential breeding distributions of U.S. birds predicted with both short-term variability and long-term average climate data

Treesearch

Brooke L. Bateman; Anna M. Pidgeon; Volker C. Radeloff; Curtis H. Flather; Jeremy VanDerWal; H. Resit Akcakaya; Wayne E. Thogmartin; Thomas P. Albright; Stephen J. Vavrus; Patricia J. Heglund

2016-01-01

Climate conditions, such as temperature or precipitation, averaged over several decades strongly affect species distributions, as evidenced by experimental results and a plethora of models demonstrating statistical relations between species occurrences and long-term climate averages. However, long-term averages can conceal climate changes that have occurred in...

Staggering reductions in atmospheric nitrogen dioxide across Canada in response to legislated transportation emissions reductions

NASA Astrophysics Data System (ADS)

Reid, Holly; Aherne, Julian

2016-12-01

It is well established that atmospheric nitrogen dioxide (NO2), associated mainly with emissions from transportation and industry, can have adverse effects on both human and ecosystem health. Specifically, atmospheric NO2 plays a role in the formation of ozone, and in acidic and nutrient deposition. As such, international agreements and national legislation, such as the On-Road Vehicle and Engine Emission Regulations (SOR/2003-2), and the Federal Agenda on Cleaner Vehicles, Engines and Fuel have been put into place to regulate and limit oxidized nitrogen emissions. The objective of this study was to assess the response of ambient air concentrations of NO2 across Canada to emissions regulations. Current NO2 levels across Canada were examined at 137 monitoring sites, and long-term annual and quarterly trends were evaluated for 63 continuous monitoring stations that had at least 10 years of data during the period 1988-2013. A non-parametric Mann-Kendall test (Z values) and Sen's slope estimate were used to determine monotonic trends; further changepoint analysis was used to determine periods with significant changes in NO2 air concentration and emissions time-series data. Current annual average NO2 levels in Canada range between 1.16 and 14.96 ppb, with the national average being 8.43 ppb. Provincially, average NO2 ranges between 3.77 and 9.25 ppb, with Ontario and British Columbia having the highest ambient levels of NO2. Long-term tend analysis indicated that the annual average NO2 air concentration decreased significantly at 87% of the stations (55 of 63), and decreased non-significantly at 10% (5 of 63) during the period 1998-2013. Concentrations increased (non-significantly) at only 3% (2 of 63) of the sites. Quarterly long-term trends showed similar results; significant decreases occurred at 84% (January-March), 88% (April-June), 83% (July-September), and 81% (October-December) of the sites. Declines in transportation emissions had the most influence on NO2 air concentrations, and changepoint analysis identified three significant changepoints for the air concentration of NO2 and transportation emissions data. The air concentration changepoints occurred immediately following changepoints in transportation emissions. The introduction of emissions limiting legislation, primarily from transportation sources, has lead to dramatic decreases of 32% in NO× emissions (42% from transportation sources [road, rail, air, marine]) and 47% in ambient NO2 concentrations across Canada. With respect to human health, legislated changes in transportation emissions have the greatest impact on ambient concentration in urban areas.

Long-Term Changes in Lower Tropospheric Baseline Ozone Concentrations:. [Comparing Chemistry-Climate Models and Observations at Northern Mid-Latitudes

NASA Technical Reports Server (NTRS)

Parrish, D. D.; Lamarque, J.-F.; Naik, V.; Horowitz, L.; Shindell, D. T.; Staehelin, J.; Derwent, R.; Cooper, O. R.; Tanimoto, H.; Volz-Thomas, A.;

Change of exposure response over time and long-term risk of silicosis among a cohort of Chinese pottery workers.

PubMed

Sun, Yi; Bochmann, Frank; Morfeld, Peter; Ulm, Kurt; Liu, Yuewei; Wang, Heijiao; Yang, Lei; Chen, Weihong

2011-07-01

An analysis was conducted on a cohort of Chinese pottery workers to estimate the exposure-response relationship between respirable crystalline silica dust exposure and the incidence of radiographically diagnosed silicosis, and to estimate the long-term risk of developing silicosis until the age of 65. The cohort comprised 3,250 employees with a median follow-up duration of around 37 years. Incident cases of silicosis were identified via silicosis registries (Chinese X-ray stage I, similar to International Labor Organisation classification scheme profusion category 1/1). Individual exposure to respirable crystalline silica dust was estimated based on over 100,000 historical dust measurements. The association between dust exposure, incidence and long-time risk of silicosis was quantified by Poisson regression analysis adjusted for age and smoking. The risk of silicosis depended not only on the cumulative respirable crystalline silica dust exposures, but also on the time-dependent respirable crystalline silica dust exposure pattern (long-term average concentration, highest annual concentration ever experienced and time since first exposure). A long-term "excess" risk of silicosis of approximately 1.5/1,000 was estimated among workers with all annual respirable crystalline silica dust concentration estimates less than 0.1 mg/m(3), using the German measurement strategy. This study indicates the importance of proper consideration of exposure information in risk quantification in epidemiological studies.

Denudation rates determined from the accumulation of in situ-produced 10Be in the luquillo experimental forest, Puerto Rico

USGS Publications Warehouse

Brown, Erik Thorson; Stallard, Robert F.; Larsen, Matthew C.; Raisbeck, Grant M.; Yiou, Francoise

1995-01-01

We present a simple method for estimation of long-term mean denudation rates using in situ-produced cosmogenic 10Be in fluvial sediments. Procedures are discussed to account for the effects of soil bioturbation, mass wasting and attenuation of cosmic rays by biomass and by local topography. Our analyses of 10Be in quartz from bedrock outcrops, soils, mass-wasting sites and riverine sediment from the Icacos River basin in the Luquillo Experimental Forest, Puerto Rico, are used to characterize denudation for major landform elements in that basin. The 10Be concentration of a discharge-weighted average of size classes of river sediment corresponds to a long-term average denudation of ≈ 43 m Ma −1, consistent with mass balance results. 

Long-term ambient ozone concentration and the incidence of asthma in nonsmoking adults: The Ahsmog study

DOE Office of Scientific and Technical Information (OSTI.GOV)

McDonnell, W.F.; Abbey, D.E.; Nishino, N.

The authors conducted a prospective study of a cohort of 3091 nonsmokers, ages 27 to 87 years, to evaluate the association between long-term ambient ozone exposure and development of adult-onset asthma. Over a 15-year period, 3.2% of males and 4.3% of females reported new doctor diagnoses of asthma. For males, they observed a significant relationship between report of doctor diagnosis of asthma and 20-year mean 8-h average ambient ozone concentration. The authors observed no such relationship for females. Other variables significantly related to development of asthma were a history of ever-smoking for males, and for females, number of years workedmore » with a smoker, age, and a history of childhood pneumonia or bronchitis. Addition of other pollutants to the models did not diminish the relationship between ozone and asthma for males. These data suggest that long-term exposure to ambient ozone is associated with development of asthma in adult males.« less

Journal Article: Atmospheric Measurements of CDDs, CDFs, and Coplanar PCBs in Rural and Remote Locations of the U.S. for the Years 1998-2001 from the National Dioxin Air Monitoring Network (Ndamn)

EPA Science Inventory

The U.S. EPA established a National Dioxin Air Monitoring Network (NDAMN) to determine background air concentrations of PCDDs, PCDFs, and cp-PCBs in rural and remote areas of the United States. Background is defined as average ambient air concentrations inferred from long-term a...

Rating curve estimation of nutrient loads in Iowa rivers

USGS Publications Warehouse

Stenback, G.A.; Crumpton, W.G.; Schilling, K.E.; Helmers, M.J.

2011-01-01

Accurate estimation of nutrient loads in rivers and streams is critical for many applications including determination of sources of nutrient loads in watersheds, evaluating long-term trends in loads, and estimating loading to downstream waterbodies. Since in many cases nutrient concentrations are measured on a weekly or monthly frequency, there is a need to estimate concentration and loads during periods when no data is available. The objectives of this study were to: (i) document the performance of a multiple regression model to predict loads of nitrate and total phosphorus (TP) in Iowa rivers and streams; (ii) determine whether there is any systematic bias in the load prediction estimates for nitrate and TP; and (iii) evaluate streamflow and concentration factors that could affect the load prediction efficiency. A commonly cited rating curve regression is utilized to estimate riverine nitrate and TP loads for rivers in Iowa with watershed areas ranging from 17.4 to over 34,600km2. Forty-nine nitrate and 44 TP datasets each comprising 5-22years of approximately weekly to monthly concentrations were examined. Three nitrate data sets had sample collection frequencies averaging about three samples per week. The accuracy and precision of annual and long term riverine load prediction was assessed by direct comparison of rating curve load predictions with observed daily loads. Significant positive bias of annual and long term nitrate loads was detected. Long term rating curve nitrate load predictions exceeded observed loads by 25% or more at 33% of the 49 measurement sites. No bias was found for TP load prediction although 15% of the 44 cases either underestimated or overestimate observed long-term loads by more than 25%. The rating curve was found to poorly characterize nitrate and phosphorus variation in some rivers. ?? 2010 .

Plasma beta-carotene is not a suitable biomarker of fruit and vegetable intake in german subjects with a long-term high consumption of fruits and vegetables.

PubMed

Garcia, A L; Mohan, R; Koebnick, C; Bub, A; Heuer, T; Strassner, C; Groeneveld, M J; Katz, N; Elmadfa, I; Leitzmann, C; Hoffmann, I

2010-01-01

beta-Carotene is often used as a marker for the amount of fruit and vegetables consumed, but little is known about plasma beta-carotene concentrations in subjects whose habitual (long-term) diets are characterized by different amounts of foods of plant origin. We compared dietary beta-carotene intake and plasma concentrations in women on habitual diets differing in the consumed amounts of foods of plant origin. A comparison of dietary beta-carotene intakes and plasma beta-carotene concentrations in women adhering to an average Western diet (n = 172), wholesome nutrition (following preventive recommendations) (n = 238) or a raw food diet (n = 104). Dietary beta-carotene intake was 5.5, 9.3, 14.7 mg/day for women adhering to an average Western diet, wholesome nutrition and raw food diet, respectively (p < 0.001). Corresponding multivariate adjusted plasma beta-carotene concentrations were 1.07, 1.65, and 1.16 micromol/l, respectively (p < 0.001). Comparable dietary beta-carotene intake resulted in lower multivariate adjusted plasma beta-carotene in women adhering to a raw food diet and average Western diet compared to those on wholesome nutrition (p < 0.001 for all intake groups up to 20 mg/day). The amount of fruit and vegetable intake did not predict plasma beta-carotene levels in women consuming a raw food diet. Plasma beta-carotene concentrations differed among the diet groups, with highest plasma levels in women adhering to wholesome nutrition. Plasma beta-carotene concentrations may not reflect beta-carotene intake and the amount of fruit and vegetables consumed. 2009 S. Karger AG, Basel.

Long-term trends of phosphorus concentrations in an artificial lake: Socio-economic and climate drivers.

PubMed

Vystavna, Yuliya; Hejzlar, Josef; Kopáček, Jiří

2017-01-01

European freshwater ecosystems have undergone significant human-induced and environmentally-driven variations in nutrient export from catchments throughout the past five decades, mainly in connection with changes in land-use, agricultural practice, waste water production and treatment, and climatic conditions. We analysed the relations among concentration of total phosphorus (TP) in the Slapy Reservoir (a middle reservoir of the Vltava River Cascade, Czechia), and socio-economic and climatic factors from 1963 to 2015. The study was based on a time series analysis, using conventional statistical tools, and the identification of breaking points, using a segmented regression. Results indicated clear long-term trends and seasonal patterns of TP, with annual average TP increasing up until 1991 and decreasing from 1992 to 2015. Trends in annual, winter and spring average TP concentrations reflected a shift in development of sewerage and sanitary infrastructure, agricultural application of fertilizers, and livestock production in the early 1990s that was associated with changes from the planned to the market economy. No trends were observed for average TP in autumn. The summer average TP has fluctuated with increased amplitude since 1991 in connection with recent climate warming, changes in thermal stratification stability, increased water flow irregularities, and short-circuiting of TP-rich inflow during high flow events. The climate-change-induced processes confound the generally declining trend in lake-water TP concentration and can result in eutrophication despite decreased phosphorus loads from the catchment. Our findings indicate the need of further reduction of phosphorus sources to meet ecological quality standards of the EU Water Framework Directive because the climate change may lead to a greater susceptibility of the aquatic ecosystem to the supply of nutrients.

Water-quality assessment of the Lower Grand River Basin, Missouri and Iowa, USA, in support of integrated conservation practices

USGS Publications Warehouse

Wilkison, Donald H.; Armstrong, Daniel J.

2016-01-01

The effectiveness of agricultural conservation programmes to adequately reduce nutrient exports to receiving streams and to help limit downstream hypoxia issues remains a concern. Quantifying programme success can be difficult given that short-term basin changes may be masked by long-term water-quality shifts. We evaluated nutrient export at stream sites in the 44 months that followed a period of increased, integrated conservation implementation within the Lower Grand River Basin. These short-term responses were then compared with export that occurred in the main stem and adjacent rivers in northern Missouri over a 22-year period to better contextualize any recent changes. Results indicate that short-term (October 2010 through May 2014) total nitrogen (TN) concentrations in the Grand River were 20% less than the long-term average, and total phosphorus (TP) concentrations were 23% less. Nutrient reductions in the short term were primarily the result of the less-than-average precipitation and, consequently, streamflow that was 36% below normal. Therefore, nutrient concentrations measured in tributary streams were likely less than normal during the implementation period. Northern Missouri streamflow-normalized TN concentrations remained relatively flat or declined over the period 1991 through 2013 likely because available sources of nitrogen, determined as the sum of commercial fertilizers, available animal manures and atmospheric inputs, were typically less than crop requirement for much of that time frame. Conversely, flow-normalized stream TP concentrations increased over the past 22 years in northern Missouri streams, likely in response to many years of phosphorus inputs in excess of crop requirements. Stream nutrient changes were most pronounced during periods that coincided with the major tillage, planting and growth phases of row crops and increased streamflow. Nutrient reduction strategies targeted at the period February through June would likely have the greatest impact on reducing nutrient export from the basin. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

Ammonia in London: is it increasing and what is the relevance of urban ammonia for air quality impacts?

NASA Astrophysics Data System (ADS)

Braban, Christine; Tang, Sim; Poskitt, Janet; Van Dijk, Netty; Leeson, Sarah; Dragosits, Ulli; Hutchings, Torben; Twigg, Marsailidh; Di Marco, Chiara; Langford, Ben; Tremper, Anja; Nemitz, Eiko; Sutton, Mark

2017-04-01

Emissions of ammonia affect both rural and urban air quality primarily via reaction of ammonia in the atmosphere forming secondary ammonium salts in particulate matter (PM). Urban ammonia emissions come from a variety of sources including biological decomposition, human waste, industrial processes and combustion engines. In the UK, the only long-term urban ammonia measurement is a UK National Ammonia Monitoring Network site at London Cromwell Road, recording monthly average concentrations. Short term measurements have also been made in the past decade at Marylebone Road, North Kensington and on the BT Tower. Cromwell Road is a kerbside site operational since 1999. The Cromwell Road data indicates that ammonia concentrations may be increasing since 2010-2012 after a long period of decreasing. Data from the National Atmospheric Emissions Inventory indicates ammonia emissions from diesel fleet exhausts increasing over this time period but an overall net decrease in ammonia emissions. With changes in engine and exhaust technology to minimise pollutant emissions and the importance of ammonia as a precursor gas for secondary PM, there is a challenge to understand urban ammonia concentrations and subsequent impacts on urban air quality. In this paper the long term measurements are assessed in conjunction with the short-term measurements.The challenges to assess the relative importance of local versus long range ammonia emission are discussed.

Long-term trends and spatial patterns of PM2.5-induced premature mortality in South and Southeast Asia from 1999 to 2014.

PubMed

Shi, Yusheng; Matsunaga, Tsuneo; Yamaguchi, Yasushi; Zhao, Aimei; Li, Zhengqiang; Gu, Xingfa

2018-08-01

Fine particulate matter (PM 2.5 ) poses a potential threat to human health, including premature mortality under long-term exposure. Based on a long-term series of high-resolution (0.01°×0.01°) satellite-retrieved PM 2.5 concentrations, this study estimated the premature mortality attributable to PM 2.5 in South and Southeast Asia (SSEA) from 1999 to 2014. Then, the long-term trends and spatial characteristics of PM 2.5 -induced premature deaths (1999-2014) were analyzed using trend analyses and standard deviation ellipses. Results showed the estimated number of PM 2.5 -induced average annual premature deaths in SSEA was 1,447,000. The numbers increased from 1,179,400 in 1999 to 1,724,900 in 2014, with a growth rate of 38% and net increase of 545,500. Stroke and ischemic heart disease were the two principal contributors, accounting for 39% and 35% of the total, respectively. High values were concentrated in North India, Bangladesh, East Pakistan, and some metropolitan areas of Southeast Asia. An estimated 991,600 deaths in India was quantified (i.e., ~69% of the total premature deaths in SSEA). The long-term trends (1999-2014) of PM 2.5 -related premature mortality exhibited consistent incremental tendencies in all countries except Sri Lanka. The findings of this study suggest that strict controls of PM 2.5 concentrations in SSEA are urgently required. Copyright © 2018 Elsevier B.V. All rights reserved.

Pollution of PM10 in an underground enclosed loading dock in Malaysia

NASA Astrophysics Data System (ADS)

Abualqumboz, M. S.; Mohammed, N. I.; Malakahmad, A.; Nazif, A. N.; Albattniji, A. T.

2016-06-01

The enclosed nature of underground loading docks results in accumulation of motor vehicles emissions. Thus, concentration of numerous harmful air pollutants including PM10 particles can increase and reach dangerous levels. This paper aims to study short-term and long-term exposure of PM10 particles inside an underground loading dock located in Malaysia. In addition, the correlation with indoor temperature, relative humidity and vehicles flow will be measured. The concentrations of PM10 were measured for three consecutive weeks using the real-time air quality monitoring instrument AQM60. Series of statistical tests and multiple linear regression analysis were applied on the data using SPSS software and MATLAB R2013a. The results illustrated that PM10 daily average concentration was in compliance with the Malaysian guideline of 150 µg/m3. Actually, 95% of instantaneous PM10 concentration readings were below 75 μg/m3. In addition, significant correlation were found between PM10 concentration and indoor temperature, relative humidity and the previous concentration. The multiple R and R2 were 0.91 and 0.83, respectively. PM10 concentration was also correlated with motor vehicles flow. In conclusion, health effects of long-term exposure to small repetitive doses of air pollutant inside underground facilities should be studied and appropriate control measures need to be implemented.

Timescales for determining temperature and dissolved oxygen trends in the Long Island Sound (LIS) estuary

NASA Astrophysics Data System (ADS)

Staniec, Allison; Vlahos, Penny

2017-12-01

Long-term time series represent a critical part of the oceanographic community's efforts to discern natural and anthropogenically forced variations in the environment. They provide regular measurements of climate relevant indicators including temperature, oxygen concentrations, and salinity. When evaluating time series, it is essential to isolate long-term trends from autocorrelation in data and noise due to natural variability. Herein we apply a statistical approach, well-established in atmospheric time series, to key parameters in the U.S. east coast's Long Island Sound estuary (LIS). Analysis shows that the LIS time series (established in the early 1990s) is sufficiently long to detect significant trends in physical-chemical parameters including temperature (T) and dissolved oxygen (DO). Over the last two decades, overall (combined surface and deep) LIS T has increased at an average rate of 0.08 ± 0.03 °C yr-1 while overall DO has dropped at an average rate of 0.03 ± 0.01 mg L-1yr-1 since 1994 at the 95% confidence level. This trend is notably faster than the global open ocean T trend (0.01 °C yr-1), as might be expected for a shallower estuarine system. T and DO trends were always significant for the existing time series using four month data increments. Rates of change of DO and T in LIS are strongly correlated and the rate of decrease of DO concentrations is consistent with the expected reduced solubility of DO at these higher temperatures. Thus, changes in T alone, across decadal timescales can account for between 33 and 100% of the observed decrease in DO. This has significant implications for other dissolved gases and the long-term management of LIS hypoxia.

Cortisol levels in hair of East Greenland polar bears

PubMed Central

Bechshøft, TØ; Sonne, C; Dietz, R; Born, EW; Novak, MA; Henchey, E; Meyer, JS

2010-01-01

To demonstrate the ability to assess long-term hypothalamic-pituitary-adrenocortical (HPA) axis activity in polar bears (Ursus maritimus), a pilot study was conducted in which cortisol concentrations was analyzed in hair from 7 female (3–19 years) and 10 male (6-19 years) East Greenland polar bears sampled 1994–2006. Hair was chosen as matrix as it is non-invasive, seasonally harmonized, and has been validated as an index of long-term changes in cortisol levels. Samples were categorized according to contamination: Eight were clean (2 females, 6 males), 5 had been contaminated with bear blood (2 F, 3 M), and 4 with bear fat (3 F, 1 M). There was no significant difference in cortisol concentration between the three categories after external contamination was removed. However, contaminated hair samples should be cleaned before cortisol determination. Average hair cortisol concentration was 8.90 pg/mg (range: 5.5 to 16.4 pg/mg). There was no significant correlation between cortisol concentration and age (p = 0.81) or sampling year (p = 0.11). However, females had higher mean cortisol concentration than males (females mean: 11.0 pg/mg, males: 7.3 pg/mg; p = 0.01). The study showed that polar bear hair contains measurable amounts of cortisol and that cortisol in hair may be used in studies of long-term stress in polar bears. PMID:21144554

Cortisol levels in hair of East Greenland polar bears.

PubMed

Bechshøft, T Ø; Sonne, C; Dietz, R; Born, E W; Novak, M A; Henchey, E; Meyer, J S

2011-01-15

To demonstrate the ability to assess long-term hypothalamic-pituitary-adrenocortical (HPA) axis activity in polar bears (Ursus maritimus), a pilot study was conducted in which cortisol concentrations was analyzed in hair from 7 female (3-19 years) and 10 male (6-19 years) East Greenland polar bears sampled in 1994-2006. The hair was chosen as matrix as it is non-invasive, seasonally harmonized, and has been validated as an index of long-term changes in cortisol levels. The samples were categorized according to contamination: eight were clean (2 females, 6 males), 5 had been contaminated with bear blood (2 F, 3 M), and 4 with bear fat (3 F, 1 M). There was no significant difference in cortisol concentration between the three categories after external contamination was removed. However, contaminated hair samples should be cleaned before cortisol determination. Average hair cortisol concentration was 8.90 pg/mg (range: 5.5 to 16.4 pg/mg). There was no significant correlation between cortisol concentration and age (p=0.81) or sampling year (p=0.11). However, females had higher mean cortisol concentration than males (females mean: 11.0 pg/mg, males: 7.3 pg/mg; p=0.01). The study showed that polar bear hair contains measurable amounts of cortisol and that cortisol in hair may be used in studies of long-term stress in polar bears. Copyright © 2010 Elsevier B.V. All rights reserved.

Neighbourhood Characteristics and Long-Term Air Pollution Levels Modify the Association between the Short-Term Nitrogen Dioxide Concentrations and All-Cause Mortality in Paris

PubMed Central

Deguen, Séverine; Petit, Claire; Delbarre, Angélique; Kihal, Wahida; Padilla, Cindy; Benmarhnia, Tarik; Lapostolle, Annabelle; Chauvin, Pierre; Zmirou-Navier, Denis

2015-01-01

Background While a great number of papers have been published on the short-term effects of air pollution on mortality, few have tried to assess whether this association varies according to the neighbourhood socioeconomic level and long-term ambient air concentrations measured at the place of residence. We explored the effect modification of 1) socioeconomic status, 2) long-term NO2 ambient air concentrations, and 3) both combined, on the association between short-term exposure to NO2 and all-cause mortality in Paris (France). Methods A time-stratified case-crossover analysis was performed to evaluate the effect of short-term NO2 variations on mortality, based on 79,107 deaths having occurred among subjects aged over 35 years, from 2004 to 2009, in the city of Paris. Simple and double interactions were statistically tested in order to analyse effect modification by neighbourhood characteristics on the association between mortality and short-term NO2 exposure. The data was estimated at the census block scale (n=866). Results The mean of the NO2 concentrations during the five days prior to deaths were associated with an increased risk of all-cause mortality: overall Excess Risk (ER) was 0.94% (95%CI=[0.08;1.80]. A higher risk was revealed for subjects living in the most deprived census blocks in comparison with higher socioeconomic level areas (ER=3.14% (95%CI=[1.41-4.90], p<0.001). Among these deprived census blocks, excess risk was even higher where long-term average NO2 concentrations were above 55.8 μg/m3 (the top tercile of distribution): ER=4.84% (95%CI=[1.56;8.24], p for interaction=0.02). Conclusion Our results show that people living in census blocks characterized by low socioeconomic status are more vulnerable to air pollution episodes. There is also an indication that people living in these disadvantaged census blocks might experience even higher risk following short-term air pollution episodes, when they are also chronically exposed to higher NO2 levels. PMID:26197409

Neighbourhood Characteristics and Long-Term Air Pollution Levels Modify the Association between the Short-Term Nitrogen Dioxide Concentrations and All-Cause Mortality in Paris.

PubMed

Deguen, Séverine; Petit, Claire; Delbarre, Angélique; Kihal, Wahida; Padilla, Cindy; Benmarhnia, Tarik; Lapostolle, Annabelle; Chauvin, Pierre; Zmirou-Navier, Denis

2015-01-01

While a great number of papers have been published on the short-term effects of air pollution on mortality, few have tried to assess whether this association varies according to the neighbourhood socioeconomic level and long-term ambient air concentrations measured at the place of residence. We explored the effect modification of 1) socioeconomic status, 2) long-term NO2 ambient air concentrations, and 3) both combined, on the association between short-term exposure to NO2 and all-cause mortality in Paris (France). A time-stratified case-crossover analysis was performed to evaluate the effect of short-term NO2 variations on mortality, based on 79,107 deaths having occurred among subjects aged over 35 years, from 2004 to 2009, in the city of Paris. Simple and double interactions were statistically tested in order to analyse effect modification by neighbourhood characteristics on the association between mortality and short-term NO2 exposure. The data was estimated at the census block scale (n=866). The mean of the NO2 concentrations during the five days prior to deaths were associated with an increased risk of all-cause mortality: overall Excess Risk (ER) was 0.94% (95%CI=[0.08;1.80]. A higher risk was revealed for subjects living in the most deprived census blocks in comparison with higher socioeconomic level areas (ER=3.14% (95%CI=[1.41-4.90], p<0.001). Among these deprived census blocks, excess risk was even higher where long-term average NO2 concentrations were above 55.8 μg/m3 (the top tercile of distribution): ER=4.84% (95%CI=[1.56;8.24], p for interaction=0.02). Our results show that people living in census blocks characterized by low socioeconomic status are more vulnerable to air pollution episodes. There is also an indication that people living in these disadvantaged census blocks might experience even higher risk following short-term air pollution episodes, when they are also chronically exposed to higher NO2 levels.

Potential breeding distributions of U.S. birds predicted with both short-term variability and long-term average climate data.

PubMed

Bateman, Brooke L; Pidgeon, Anna M; Radeloff, Volker C; Flather, Curtis H; VanDerWal, Jeremy; Akçakaya, H Resit; Thogmartin, Wayne E; Albright, Thomas P; Vavrus, Stephen J; Heglund, Patricia J

2016-12-01

Climate conditions, such as temperature or precipitation, averaged over several decades strongly affect species distributions, as evidenced by experimental results and a plethora of models demonstrating statistical relations between species occurrences and long-term climate averages. However, long-term averages can conceal climate changes that have occurred in recent decades and may not capture actual species occurrence well because the distributions of species, especially at the edges of their range, are typically dynamic and may respond strongly to short-term climate variability. Our goal here was to test whether bird occurrence models can be predicted by either covariates based on short-term climate variability or on long-term climate averages. We parameterized species distribution models (SDMs) based on either short-term variability or long-term average climate covariates for 320 bird species in the conterminous USA and tested whether any life-history trait-based guilds were particularly sensitive to short-term conditions. Models including short-term climate variability performed well based on their cross-validated area-under-the-curve AUC score (0.85), as did models based on long-term climate averages (0.84). Similarly, both models performed well compared to independent presence/absence data from the North American Breeding Bird Survey (independent AUC of 0.89 and 0.90, respectively). However, models based on short-term variability covariates more accurately classified true absences for most species (73% of true absences classified within the lowest quarter of environmental suitability vs. 68%). In addition, they have the advantage that they can reveal the dynamic relationship between species and their environment because they capture the spatial fluctuations of species potential breeding distributions. With this information, we can identify which species and guilds are sensitive to climate variability, identify sites of high conservation value where climate variability is low, and assess how species' potential distributions may have already shifted due recent climate change. However, long-term climate averages require less data and processing time and may be more readily available for some areas of interest. Where data on short-term climate variability are not available, long-term climate information is a sufficient predictor of species distributions in many cases. However, short-term climate variability data may provide information not captured with long-term climate data for use in SDMs. © 2016 by the Ecological Society of America.

Long short-term memory neural network for air pollutant concentration predictions: Method development and evaluation.

PubMed

Li, Xiang; Peng, Ling; Yao, Xiaojing; Cui, Shaolong; Hu, Yuan; You, Chengzeng; Chi, Tianhe

2017-12-01

Air pollutant concentration forecasting is an effective method of protecting public health by providing an early warning against harmful air pollutants. However, existing methods of air pollutant concentration prediction fail to effectively model long-term dependencies, and most neglect spatial correlations. In this paper, a novel long short-term memory neural network extended (LSTME) model that inherently considers spatiotemporal correlations is proposed for air pollutant concentration prediction. Long short-term memory (LSTM) layers were used to automatically extract inherent useful features from historical air pollutant data, and auxiliary data, including meteorological data and time stamp data, were merged into the proposed model to enhance the performance. Hourly PM 2.5 (particulate matter with an aerodynamic diameter less than or equal to 2.5 μm) concentration data collected at 12 air quality monitoring stations in Beijing City from Jan/01/2014 to May/28/2016 were used to validate the effectiveness of the proposed LSTME model. Experiments were performed using the spatiotemporal deep learning (STDL) model, the time delay neural network (TDNN) model, the autoregressive moving average (ARMA) model, the support vector regression (SVR) model, and the traditional LSTM NN model, and a comparison of the results demonstrated that the LSTME model is superior to the other statistics-based models. Additionally, the use of auxiliary data improved model performance. For the one-hour prediction tasks, the proposed model performed well and exhibited a mean absolute percentage error (MAPE) of 11.93%. In addition, we conducted multiscale predictions over different time spans and achieved satisfactory performance, even for 13-24 h prediction tasks (MAPE = 31.47%). Copyright © 2017 Elsevier Ltd. All rights reserved.

Global Estimates of Ambient Fine Particulate Matter Concentrations from Satellite-Based Aerosol Optical Depth: Development and Application

PubMed Central

van Donkelaar, Aaron; Martin, Randall V.; Brauer, Michael; Kahn, Ralph; Levy, Robert; Verduzco, Carolyn; Villeneuve, Paul J.

2010-01-01

Background Epidemiologic and health impact studies of fine particulate matter with diameter < 2.5 μm (PM2.5) are limited by the lack of monitoring data, especially in developing countries. Satellite observations offer valuable global information about PM2.5 concentrations. Objective In this study, we developed a technique for estimating surface PM2.5 concentrations from satellite observations. Methods We mapped global ground-level PM2.5 concentrations using total column aerosol optical depth (AOD) from the MODIS (Moderate Resolution Imaging Spectroradiometer) and MISR (Multiangle Imaging Spectroradiometer) satellite instruments and coincident aerosol vertical profiles from the GEOS-Chem global chemical transport model. Results We determined that global estimates of long-term average (1 January 2001 to 31 December 2006) PM2.5 concentrations at approximately 10 km × 10 km resolution indicate a global population-weighted geometric mean PM2.5 concentration of 20 μg/m3. The World Health Organization Air Quality PM2.5 Interim Target-1 (35 μg/m3 annual average) is exceeded over central and eastern Asia for 38% and for 50% of the population, respectively. Annual mean PM2.5 concentrations exceed 80 μg/m3 over eastern China. Our evaluation of the satellite-derived estimate with ground-based in situ measurements indicates significant spatial agreement with North American measurements (r = 0.77; slope = 1.07; n = 1057) and with noncoincident measurements elsewhere (r = 0.83; slope = 0.86; n = 244). The 1 SD of uncertainty in the satellite-derived PM2.5 is 25%, which is inferred from the AOD retrieval and from aerosol vertical profile errors and sampling. The global population-weighted mean uncertainty is 6.7 μg/m3. Conclusions Satellite-derived total-column AOD, when combined with a chemical transport model, provides estimates of global long-term average PM2.5 concentrations. PMID:20519161

Rising trends of dissolved organic matter in drinking-water reservoirs as a result of recovery from acidification in the Ore Mts., Czech Republic.

PubMed

Oulehle, Filip; Hruska, Jakub

2009-12-01

The concentration of chemical oxygen demand (COD), a common proxy for dissolved organic matter (DOM), was measured at seven drinking-water reservoirs and four streams between 1969 and 2006. Nine of them showed significant DOM increases (median COD change +0.08 mg L(-1) yr(-1)). Several potential drivers of these trends were considered, including air temperature, rainfall, land-use and water sulfate concentration. Temperature and precipitation influenced inter-annual variations, but not long-term trends. The long-term DOM increase was significantly associated with declines of acidic deposition, especially sulfur deposition. Surface water sulfate concentrations decreased from a median of 62 mg L(-1)-27 mg L(-1) since 1980. The magnitude of DOM increase was positively correlated with average DOM concentration (R(2) = 0.79, p < 0.001). Simultaneously, DOM concentration was positively correlated with the proportion of Histosols within the catchments (R(2) = 0.79, p < 0.001). A focus on the direct removal of DOM by water treatment procedures rather than catchment remediation is needed.

An Association Between Long-Term Exposure to Ambient Air Pollution and Mortality From Lung Cancer and Respiratory Diseases in Japan

PubMed Central

Katanoda, Kota; Sobue, Tomotaka; Satoh, Hiroshi; Tajima, Kazuo; Suzuki, Takaichiro; Nakatsuka, Haruo; Takezaki, Toshiro; Nakayama, Tomio; Nitta, Hiroshi; Tanabe, Kiyoshi; Tominaga, Suketami

2011-01-01

Background Evidence for a link between long-term exposure to air pollution and lung cancer is limited to Western populations. In this prospective cohort study, we examined this association in a Japanese population. Methods The study comprised 63 520 participants living in 6 areas in 3 Japanese prefectures who were enrolled between 1983 and 1985. Exposure to particulate matter less than 2.5 µm in aerodynamic diameter (PM2.5), sulfur dioxide (SO2), and nitrogen dioxide (NO2) was assessed using data from monitoring stations located in or nearby each area. The Cox proportional hazards model was used to calculate the hazard ratios associated with the average concentrations of these air pollutants. Results The 10-year average concentrations of PM2.5, SO2, and NO2 before recruitment (1974–1983) were 16.8 to 41.9 µg/m3, 2.4 to 19.0 ppb, and 1.2 to 33.7 ppb, respectively (inter-area range). During an average follow-up of 8.7 years, there were 6687 deaths, including 518 deaths from lung cancer. The hazard ratios for lung cancer mortality associated with a 10-unit increase in PM2.5 (µg/m3), SO2 (ppb), and NO2 (ppb) were 1.24 (95% confidence interval: 1.12–1.37), 1.26 (1.07–1.48), and 1.17 (1.10–1.26), respectively, after adjustment for tobacco smoking and other confounding factors. In addition, a significant increase in risk was observed for male smokers and female never smokers. Respiratory diseases, particularly pneumonia, were also significantly associated with all the air pollutants. Conclusions Long-term exposure to air pollution is associated with lung cancer and respiratory diseases in Japan. PMID:21325732

An association between long-term exposure to ambient air pollution and mortality from lung cancer and respiratory diseases in Japan.

PubMed

Katanoda, Kota; Sobue, Tomotaka; Satoh, Hiroshi; Tajima, Kazuo; Suzuki, Takaichiro; Nakatsuka, Haruo; Takezaki, Toshiro; Nakayama, Tomio; Nitta, Hiroshi; Tanabe, Kiyoshi; Tominaga, Suketami

2011-01-01

Evidence for a link between long-term exposure to air pollution and lung cancer is limited to Western populations. In this prospective cohort study, we examined this association in a Japanese population. The study comprised 63 520 participants living in 6 areas in 3 Japanese prefectures who were enrolled between 1983 and 1985. Exposure to particulate matter less than 2.5 µm in aerodynamic diameter (PM(2.5)), sulfur dioxide (SO(2)), and nitrogen dioxide (NO(2)) was assessed using data from monitoring stations located in or nearby each area. The Cox proportional hazards model was used to calculate the hazard ratios associated with the average concentrations of these air pollutants. The 10-year average concentrations of PM(2.5), SO(2), and NO(2) before recruitment (1974-1983) were 16.8 to 41.9 µg/m(3), 2.4 to 19.0 ppb, and 1.2 to 33.7 ppb, respectively (inter-area range). During an average follow-up of 8.7 years, there were 6687 deaths, including 518 deaths from lung cancer. The hazard ratios for lung cancer mortality associated with a 10-unit increase in PM(2.5) (µg/m(3)), SO(2) (ppb), and NO(2) (ppb) were 1.24 (95% confidence interval: 1.12-1.37), 1.26 (1.07-1.48), and 1.17 (1.10-1.26), respectively, after adjustment for tobacco smoking and other confounding factors. In addition, a significant increase in risk was observed for male smokers and female never smokers. Respiratory diseases, particularly pneumonia, were also significantly associated with all the air pollutants. Long-term exposure to air pollution is associated with lung cancer and respiratory diseases in Japan.

The influence of a season of extreme wet weather events on exposure of the World Heritage Area Great Barrier Reef to pesticides.

PubMed

Kennedy, Karen; Devlin, Michelle; Bentley, Christie; Lee-Chue, Kristie; Paxman, Chris; Carter, Steve; Lewis, Stephen E; Brodie, Jon; Guy, Ellia; Vardy, Suzanne; Martin, Katherine C; Jones, Alison; Packett, Robert; Mueller, Jochen F

2012-07-01

The 2010-2011 wet season was one of extreme weather for the State of Queensland, Australia. Major rivers adjacent to the Great Barrier Reef (GBR) were discharging at rates 1.5 to >3 times higher than their long term median. Exposure to photosystem II herbicides has been routinely monitored over a period of up to 5 years at 12 inshore GBR sites. The influence of this wet season on exposure to photosystem II herbicides was examined in the context of this long-term monitoring record and during flood plume events in specific regions. Median exposures expressed as diuron equivalent concentration were an average factor of 2.3 times higher but mostly not significantly different (p<0.05) to the median for the long-term monitoring record. The herbicides metolachlor and tebuthiuron were frequently detected in flood plume waters at concentrations that reached or exceeded relevant water quality guidelines (by up to 4.5 times). Copyright © 2012 Elsevier Ltd. All rights reserved.

Long-term limnological data from the larger lakes of Yellowstone National Park, Wyoming, USA

USGS Publications Warehouse

Theriot, E.C.; Fritz, S.C.; Gresswell, Robert E.

1997-01-01

Long-term limnological data from the four largest lakes in Yellowstone National Park (Yellowstone, Lewis, Shoshone, Heart) are used to characterize their limnology and patterns of temporal and spatial variability. Heart Lake has distinctively high concentrations of dissolved materials, apparently reflecting high thermal inputs. Shoshone and Lewis lakes have the highest total SiO2 concentrations (averaging over 23.5 mg L-1), apparently as a result of the rhyolitic drainage basins. Within Yellowstone Lake spatial variability is low and ephemeral for most measured variables, except that the Southeast Arm has lower average Na concentrations. Seasonal variation is evident for Secchi transparency, pH, and total-SiO2 and probably reflects seasonal changes in phytoplankton biomass and productivity. Total dissolved solids (TDS) and total-SiO2 generally show a gradual decline from the mid-1970s through mid-1980s, followed by a sharp increase. Ratios of Kjeldahl-N to total-PO4 (KN:TP) suggest that the lakes, especially Shoshone, are often nitrogen limited. Kjeldahl-N is positively correlated with winter precipitation, but TP and total-SiO2 are counterintuitively negatively correlated with precipitation. We speculate that increased winter precipitation, rather than watershed fires, increases N-loading which, in turn, leads to increased demand for TP and total SiO2.

Long-term dynamics of freshwater red tide in shallow lake in central Japan.

PubMed

Hirabayashi, Kimio; Yoshizawa, Kazuya; Yoshida, Norihiko; Ariizumi, Kazunori; Kazama, Futaba

2007-01-01

The aim of this study is to clarify the long-term dynamics of the red tide occurring in Lake Kawaguchi. The measurement of environmental factors and water sampling were carried out monthly at a fixed station in Lake Kawaguchi's center basin from April 1993 to March 2004. On June 26, 1995, the horizontal distribution ofPeridinium bipes was investigated using a plastic pipe, obtaining 0∼1-m layers of water column samples at 68 locations across the entire lake. P. bipes showed an explosive growth and formed a freshwater red tide in the early summer of 1995, when the nutrient level was higher than those in the other years, particularly the phosphate concentration in the surface layer. The dissolved total phosphorus (DTP) concentration was sufficient forP. bipes growth in that year. In the study of its horizontal distribution,P. bipes was found at all the locations. The numbers of cells per milliliter ranged from 67 to 5360, averaging 1094±987 cells/ml, with particularly high densities along the northern shore. Since then,P. bipes has annually averaged about 25 cells/ml in Lake Kawaguchi. We observed that the red tide caused byP. bipes correlates with a high DTP concentration in Lake Kawaguchi.

Stability of drugs of abuse in urine samples stored at -20 degrees C.

PubMed

Dugan, S; Bogema, S; Schwartz, R W; Lappas, N T

1994-01-01

Isolated studies of the stability of individual drugs of abuse have been reported. However, few have evaluated stability in frozen urine samples stored for 12 months. We have determined the stability of 11-nor-9-carboxy-delta 9-tetrahydrocannabinol (9-COOH-THC), amphetamine, methamphetamine, morphine, codeine, cocaine, benzoylecgonine, and phencyclidine in 236 physiological urine samples. Following the initial quantitative analysis, the samples were stored at -20 degrees C for 12 months and then reanalyzed. All drug concentrations were determined by gas chromatographic-mass spectrometric methods with cutoff concentrations of 5 ng/mL for 9-COOH-THC and phencyclidine and 100 ng/mL for each of the other drugs. The average change in the concentrations of these drugs following this long-term storage was not extensive except for an average change of -37% in cocaine concentrations.

40 CFR 439.52 - Effluent limitations attainable by the application of the best practicable control technology...

Code of Federal Regulations, 2012 CFR

2012-07-01

..., kg) per day, must reflect not less than 74 percent reduction in the long-term average daily COD load... long-term average daily BOD5 or COD mass loading of the raw process wastewater (i.e., the base number..., calculation of the long-term average daily BOD5 or COD load in the influent to the wastewater treatment system...

40 CFR 439.52 - Effluent limitations attainable by the application of the best practicable control technology...

Code of Federal Regulations, 2014 CFR

2014-07-01

..., kg) per day, must reflect not less than 74 percent reduction in the long-term average daily COD load... long-term average daily BOD5 or COD mass loading of the raw process wastewater (i.e., the base number..., calculation of the long-term average daily BOD5 or COD load in the influent to the wastewater treatment system...

40 CFR 439.52 - Effluent limitations attainable by the application of the best practicable control technology...

Code of Federal Regulations, 2013 CFR

2013-07-01

..., kg) per day, must reflect not less than 74 percent reduction in the long-term average daily COD load... long-term average daily BOD5 or COD mass loading of the raw process wastewater (i.e., the base number..., calculation of the long-term average daily BOD5 or COD load in the influent to the wastewater treatment system...

40 CFR 439.12 - Effluent limitations attainable by the application of the best practicable control technology...

Code of Federal Regulations, 2013 CFR

2013-07-01

... than 90 percent reduction in the long-term average daily BOD5 load of the raw (untreated) process wastewater, multiplied by a variability factor of 3.0. (1) The long-term average daily BOD5 load of the raw..., calculation of the long-term average daily BOD5 load in the influent to the wastewater treatment system must...

40 CFR 439.12 - Effluent limitations attainable by the application of the best practicable control technology...

Code of Federal Regulations, 2012 CFR

2012-07-01

... than 90 percent reduction in the long-term average daily BOD5 load of the raw (untreated) process wastewater, multiplied by a variability factor of 3.0. (1) The long-term average daily BOD5 load of the raw..., calculation of the long-term average daily BOD5 load in the influent to the wastewater treatment system must...

40 CFR 439.12 - Effluent limitations attainable by the application of the best practicable control technology...

Code of Federal Regulations, 2014 CFR

2014-07-01

... than 90 percent reduction in the long-term average daily BOD5 load of the raw (untreated) process wastewater, multiplied by a variability factor of 3.0. (1) The long-term average daily BOD5 load of the raw..., calculation of the long-term average daily BOD5 load in the influent to the wastewater treatment system must...

Nitric acid measurements in connection with corrosion studies

NASA Astrophysics Data System (ADS)

Ferm, Martin; De Santis, Franco; Varotsos, Costas

Atmospheric nitric acid does not only contribute to acidification and eutrophication but causes also deterioration of many materials. Material belonging to our cultural heritage is irreplaceable and its lifetime can depend on the corrosion rate. Nowadays, only very few long-term measurements of nitric acid concentration in Europe and elsewhere have been published so far. Due to the fact that atmospheric corrosion is a long-term effect, the relevant research does not necessarily require monitoring of nitric acid on a daily basis. Moreover, power supply is often not available at sites where it is of interest to study the corrosion rate of objects belonging to our cultural heritage. Besides, such measurements must not disturb the impression of the objects. In this context, the diffusive sampling technique provides average concentrations over long-term periods at a low cost. In addition, the samplers used are noiseless, comparatively small in size, and thus, their ambient exposure can be made inconspicuously and with discretion. The present paper is focussed on an intensive corrosion study, which was performed at 11 rural and 23 urban sites in Europe and one rural site in Canada during 2002/2003. For the above-mentioned reasons, the diffusive sampler's technique was employed for the nitric acid monitoring, where the diffusive samplers were first tested against the denuder technique and bi-monthly measurements of nitric acid were thus obtained. The bi-monthly concentrations varied from 0.05 to 4.3 μg m -3 and the annual averages from 0.16 to 2.0 μg m -3. The observations collected, depicted a summertime maximum and a wintertime minimum in the nitric acid concentrations, except at the northern rural sites, where a maximum in the winter was observed. Furthermore, the observed nitric acid concentrations in Southern Europe were higher than in Northern Europe. In a few places, close to the sites of urban measurements, rural measurements of nitric acid were also performed. The obtained nitric acid concentrations were higher in the cities, especially during the period of maximum concentrations.

Effects of long-term exposure to air pollution on natural-cause mortality: an analysis of 22 European cohorts within the multicentre ESCAPE project.

PubMed

Beelen, Rob; Raaschou-Nielsen, Ole; Stafoggia, Massimo; Andersen, Zorana Jovanovic; Weinmayr, Gudrun; Hoffmann, Barbara; Wolf, Kathrin; Samoli, Evangelia; Fischer, Paul; Nieuwenhuijsen, Mark; Vineis, Paolo; Xun, Wei W; Katsouyanni, Klea; Dimakopoulou, Konstantina; Oudin, Anna; Forsberg, Bertil; Modig, Lars; Havulinna, Aki S; Lanki, Timo; Turunen, Anu; Oftedal, Bente; Nystad, Wenche; Nafstad, Per; De Faire, Ulf; Pedersen, Nancy L; Östenson, Claes-Göran; Fratiglioni, Laura; Penell, Johanna; Korek, Michal; Pershagen, Göran; Eriksen, Kirsten Thorup; Overvad, Kim; Ellermann, Thomas; Eeftens, Marloes; Peeters, Petra H; Meliefste, Kees; Wang, Meng; Bueno-de-Mesquita, Bas; Sugiri, Dorothea; Krämer, Ursula; Heinrich, Joachim; de Hoogh, Kees; Key, Timothy; Peters, Annette; Hampel, Regina; Concin, Hans; Nagel, Gabriele; Ineichen, Alex; Schaffner, Emmanuel; Probst-Hensch, Nicole; Künzli, Nino; Schindler, Christian; Schikowski, Tamara; Adam, Martin; Phuleria, Harish; Vilier, Alice; Clavel-Chapelon, Françoise; Declercq, Christophe; Grioni, Sara; Krogh, Vittorio; Tsai, Ming-Yi; Ricceri, Fulvio; Sacerdote, Carlotta; Galassi, Claudia; Migliore, Enrica; Ranzi, Andrea; Cesaroni, Giulia; Badaloni, Chiara; Forastiere, Francesco; Tamayo, Ibon; Amiano, Pilar; Dorronsoro, Miren; Katsoulis, Michail; Trichopoulou, Antonia; Brunekreef, Bert; Hoek, Gerard

2014-03-01

Few studies on long-term exposure to air pollution and mortality have been reported from Europe. Within the multicentre European Study of Cohorts for Air Pollution Effects (ESCAPE), we aimed to investigate the association between natural-cause mortality and long-term exposure to several air pollutants. We used data from 22 European cohort studies, which created a total study population of 367,251 participants. All cohorts were general population samples, although some were restricted to one sex only. With a strictly standardised protocol, we assessed residential exposure to air pollutants as annual average concentrations of particulate matter (PM) with diameters of less than 2.5 μm (PM2.5), less than 10 μm (PM10), and between 10 μm and 2.5 μm (PMcoarse), PM2.5 absorbance, and annual average concentrations of nitrogen oxides (NO2 and NOx), with land use regression models. We also investigated two traffic intensity variables-traffic intensity on the nearest road (vehicles per day) and total traffic load on all major roads within a 100 m buffer. We did cohort-specific statistical analyses using confounder models with increasing adjustment for confounder variables, and Cox proportional hazards models with a common protocol. We obtained pooled effect estimates through a random-effects meta-analysis. The total study population consisted of 367,251 participants who contributed 5,118,039 person-years at risk (average follow-up 13.9 years), of whom 29,076 died from a natural cause during follow-up. A significantly increased hazard ratio (HR) for PM2.5 of 1.07 (95% CI 1.02-1.13) per 5 μg/m(3) was recorded. No heterogeneity was noted between individual cohort effect estimates (I(2) p value=0.95). HRs for PM2.5 remained significantly raised even when we included only participants exposed to pollutant concentrations lower than the European annual mean limit value of 25 μg/m(3) (HR 1.06, 95% CI 1.00-1.12) or below 20 μg/m(3) (1.07, 1.01-1.13). Long-term exposure to fine particulate air pollution was associated with natural-cause mortality, even within concentration ranges well below the present European annual mean limit value. European Community's Seventh Framework Program (FP7/2007-2011). Copyright © 2014 Elsevier Ltd. All rights reserved.

Design and performance of limestone drains to increase pH and remove metals from acidic mine drainage, Chapter 2

USGS Publications Warehouse

Cravotta,, Charles A.; Watzlaf, George R.

2002-01-01

Data on the construction characteristics and the composition of influent and effluent at 13 underground, limestone-filled drains in Pennsylvania and Maryland are reported to evaluate the design and performance of limestone drains for the attenuation of acidity and dissolved metals in acidic mine drainage. On the basis of the initial mass of limestone, dimensions of the drains, and average flow rates, the initial porosity and average detention time for each drain were computed. Calculated porosity ranged from 0.12 to 0.50 with corresponding detention times at average flow from 1.3 to 33 h. The effectiveness of treatment was dependent on influent chemistry, detention time, and limestone purity. At two sites where influent contained elevated dissolved Al (>5 mg/liter), drain performance declined rapidly; elsewhere the drains consistently produced near-neutral effluent, even when influent contained small concentrations of dissolved Fe^+ (<5 mg/liter). Rates of limestone dissolution computed on the basis of average long-term Ca ion flux normalized by initial mass and purity of limestone at each of the drains ranged from 0.008 to 0.079 year-1. Data for alkalinity concentration and flux during 11-day closed-container tests using an initial mass of 4kg crushed limestone and a solution volume of 2.3 liter yielded dissolution rate constants that were comparable to these long-term field rates. An analytical method is proposed using closed-container test data to evaluate long-term performance (longevity) or to estimate the mass of limestone needed for a limestone treatment. This method condisers flow rate, influent alkalinity, steady-state alkalinity of effluent, and desired effluent alkalinity or detention time at a future time(s) and aplies first-order rate laws for limestone dissolution (continuous) and production of alkalinity (bounded).

Optimizing a Sensor Network with Data from Hazard Mapping Demonstrated in a Heavy-Vehicle Manufacturing Facility.

PubMed

Berman, Jesse D; Peters, Thomas M; Koehler, Kirsten A

2018-05-28

To design a method that uses preliminary hazard mapping data to optimize the number and location of sensors within a network for a long-term assessment of occupational concentrations, while preserving temporal variability, accuracy, and precision of predicted hazards. Particle number concentrations (PNCs) and respirable mass concentrations (RMCs) were measured with direct-reading instruments in a large heavy-vehicle manufacturing facility at 80-82 locations during 7 mapping events, stratified by day and season. Using kriged hazard mapping, a statistical approach identified optimal orders for removing locations to capture temporal variability and high prediction precision of PNC and RMC concentrations. We compared optimal-removal, random-removal, and least-optimal-removal orders to bound prediction performance. The temporal variability of PNC was found to be higher than RMC with low correlation between the two particulate metrics (ρ = 0.30). Optimal-removal orders resulted in more accurate PNC kriged estimates (root mean square error [RMSE] = 49.2) at sample locations compared with random-removal order (RMSE = 55.7). For estimates at locations having concentrations in the upper 10th percentile, the optimal-removal order preserved average estimated concentrations better than random- or least-optimal-removal orders (P < 0.01). However, estimated average concentrations using an optimal-removal were not statistically different than random-removal when averaged over the entire facility. No statistical difference was observed for optimal- and random-removal methods for RMCs that were less variable in time and space than PNCs. Optimized removal performed better than random-removal in preserving high temporal variability and accuracy of hazard map for PNC, but not for the more spatially homogeneous RMC. These results can be used to reduce the number of locations used in a network of static sensors for long-term monitoring of hazards in the workplace, without sacrificing prediction performance.

Atmospheric CO2 From Flask Air Samples at 10 Sites in the Scripps Institution of Oceanography (SIO) Air Sampling Network (1957 - 2001) (issued 2004)

DOE Data Explorer

Keeling, Charles D. [Univ. of California, San Diego, CA (United States). Scripps Inst. of Oceanography; Whorf, Timothy P. [Univ. of California, San Diego, CA (United States). Scripps Inst. of Oceanography; Blasing, T. J. [Carbon Dioxide Information Analysis Center (CDIAC), Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (USA); Jones, Sonja [Carbon Dioxide Information Analysis Center (CDIAC), Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (USA)

2004-09-01

The Carbon Dioxide Research Group, Scripps Institution of Oceanography, University of California, San Diego, has provided this data set, which includes long-term measurements of near-surface atmospheric CO2 concentrations at 10 locations spanning latitudes 82°N to 90°S. Most of the data are based on replicated (collected at the same time and place) flask samples taken at intervals of approximately one week to one month and subsequently subjected to infrared analysis. Periods of record begin in various years, ranging from 1957 (for the South Pole station) to 1985 (for Alert, Canada), and all flask data records except for Christmas Island and Baring Head, New Zealand extend through year 2001. Christmas Island data end with August, 2001 and Baring Head data end with October 2001. Weekly averages of continuous data from Mauna Loa Observatory, Hawaii, are available back to March 1958. Similar weekly averages are also available for La Jolla, California, from November 1972 to October 1975, and for the South Pole from June 1960 to October 1963. These long-term records of atmospheric CO2 concentration complement the continuous records made by SIO, and also complement the long term flask records of the Climate Monitoring and Diagnostics Laboratory of the National Oceanic and Atmospheric Administration. All these data are useful for characterizing seasonal and geographical variations in atmospheric CO2 over several years, and for assessing results of global carbon models.

Long-term variation of the concentrations of long-lived Rn descendants and cosmogenic 7Be and determination of the MRT of aerosols

NASA Astrophysics Data System (ADS)

Dueñas, C.; Fernández, M. C.; Carretero, J.; Liger, E.; Cañete, S.

During a 6 years period, the atmospheric activity concentrations of the long-lived 222Rn daughters and 7Be concentrations were measured at Málaga (36° 43'40″ N; 4° 28'8″ W). The concentration data of long-lived radon daughters and 7Be together with meteorological variables were used for a comprehensive regression analysis of weekly variation of radioactivity in air. The seasonal variations of the concentrations show similar trend for the long-lived daughters of radon and 7Be concentrations. The activity concentrations were observed to be higher during the summer months than in other seasons. From the ratio between the activity concentrations of 210Po and 210Pb, a mean residence time of aerosol particles in the atmosphere of about 31 days was obtained. The average concentrations values of 210Pb and 7Be over the 6 years period have been found to be 510 and 4.6 mBq m -3, respectively. A mean aerosol mass concentrations of (46.6±7.8) μg m -3 was also determined during the period of measurements. The 7Be/ 210Pb activity ratios varied between 11 and 8.4. Correlation study has been carried out between the aerosol mass and concentrations of these tracers.

Characterization of air manganese exposure estimates for residents in two Ohio towns

PubMed Central

Colledge, Michelle A.; Julian, Jaime R.; Gocheva, Vihra V.; Beseler, Cheryl L.; Roels, Harry A.; Lobdell, Danelle T.; Bowler, Rosemarie M.

2016-01-01

This study was conducted to derive receptor-specific outdoor exposure concentrations of total suspended particulate (TSP) and respirable (dae ≤ 10 μm) air manganese (air-Mn) for East Liverpool and Marietta (Ohio) in the absence of facility emissions data, but where long-term air measurements were available. Our “site-surface area emissions method” used U.S. Environmental Protection Agency’s (EPA) AERMOD (AMS/EPA Regulatory Model) dispersion model and air measurement data to estimate concentrations for residential receptor sites in the two communities. Modeled concentrations were used to create ratios between receptor points and calibrated using measured data from local air monitoring stations. Estimated outdoor air-Mn concentrations were derived for individual study subjects in both towns. The mean estimated long-term air-Mn exposure levels for total suspended particulate were 0.35 μg/m3 (geometric mean [GM]) and 0.88 μg/m3 (arithmetic mean [AM]) in East Liverpool (range: 0.014–6.32 μg/m3) and 0.17 μg/m3 (GM) and 0.21 μg/m3 (AM) in Marietta (range: 0.03–1.61 μg/m3). Modeled results compared well with averaged ambient air measurements from local air monitoring stations. Exposure to respirable Mn particulate matter (PM10; PM <10 μm) was higher in Marietta residents. Implications Few available studies evaluate long-term health outcomes from inhalational manganese (Mn) exposure in residential populations, due in part to challenges in measuring individual exposures. Local long-term air measurements provide the means to calibrate models used in estimating long-term exposures. Furthermore, this combination of modeling and ambient air sampling can be used to derive receptor-specific exposure estimates even in the absence of source emissions data for use in human health outcome studies. PMID:26211636

Monitoring of formaldehyde in air

DOE Office of Scientific and Technical Information (OSTI.GOV)

Balmat, J.L.; Meadows, G.W.

1985-10-01

Any one of several monitoring methods, depending on requirement and circumstance, can be used to measure employee exposure to formaldehyde. Ordinarily, monitoring at DuPont is performed by sampling with impingers containing 1% aqueous sodium bisulfite or with silica gel tubes. The collected formaldehyde is measured spectrophotometrically after reaction with chromotropic acid. Results from studies on a selected number of formaldehyde monitoring methods reveal that reliable methods are available for area and personnel monitoring over both short term and long term. Accurate results are obtained from short-term monitoring (15 min at 1 L/min) with impingers of formaldehyde concentrations as low asmore » 0.14 ppm. The current studies show that long-term monitoring (8 hr at 0.5 L/min) can be performed accurately at concentrations as low as 0.05 ppm. Accurate results also are obtained from short-term monitoring (15 min at 500 mL/min) with silica gel tubes of concentrations as low as 0.11 ppm formaldehyde. Passive monitors provide the most convenient means of obtaining 8-hour time-weighted average (TWA) data. The Pro-Tek Formaldehyde Badge was demonstrated to reliably monitor formaldehyde concentrations varying from 0-0.5 ppm or 0-3 ppm. Investigation of the Lion Formaldemeter disclosed that instantaneous and accurate (+/- 5%) measurement of formaldehyde in air can be made over a concentration range of 0.3-5 ppm in the absence of other substances that are oxidizable in its fuel cell detector.« less

Personal carbon monoxide exposure in Helsinki, Finland

NASA Astrophysics Data System (ADS)

Scotto di Marco, Greta; Kephalopoulos, Stylianos; Ruuskanen, Juhani; Jantunen, Matti

Personal exposure concentrations of carbon monoxide (CO) were measured for the adult urban population of Helsinki, Finland, as part of the multi-centre European EXPOLIS study. The arithmetic mean of the 48 h average personal CO exposure concentration was 1.3 mg m -3 for participants not exposed to environmental tobacco smoke (ETS) and 1.6 mg m -3 for those exposed to ETS at any time and in any microenvironment. The maximum 8 and 1 h exposure values were 2.0 and 2.6 mg m -3, and 4.3 and 5.7 mg m -3, respectively. As tobacco smoke is one of the major sources of CO, therefore the personal mean exposures of ETS participants were higher than the non-ETS participants for all averaging times. The long- and short-term personal exposures were higher in winter than in summer for all participants. In order to analyse in more detail the correlation between the time-activity patterns and exposure levels, cluster analysis was performed using 24 h personal exposure profiles of 1 h moving averages. The results showed clearly that the major source of CO for non-ETS exposed participants are traffic emissions. The majority of the diurnal exposure profiles showed two notable exposure peaks corresponding to the morning and evening traffic rush hours. The time spent in street traffic was the most relevant factor for describing the short-term personal exposures. The more time was spent commuting by car the higher were the exposures. The long-term exposure levels were linked both to the time spent commuting and home location. People living in low-traffic suburban areas and working in downtown spent more time commuting and ended up experiencing similar long-term exposure levels than people who lived in heavy-traffic downtown areas, but spent little time commuting. For ETS exposed participants the personal exposure profiles were dominated by both tobacco smoke and traffic emissions.

Measurement of the concentration of radon gas in the Toirano's caves (Liguria).

PubMed

Bruzzone, Diego; Bussallino, Massimo; Castello, Gianrico; Maggiolo, Stefano; Rossi, Daniela

2006-01-01

The radioactive gas radon, intermediate term of the decay series of uranium and thorium, is the main contamination source of underground places and may be a risk for high concentration and long exposure time. European and Italian law requires radon concentration to be measured in workplaces and, if the "action level" of 500 Bq/m3 is reached, proper actions must be made in order to decrease the dose commitment. Considering natural showcaves or artificial cavities open to public, the exposition of the visitors is frequently small, due to the short residence time, but accompanying people, remaining underground for long time, may be subject to appreciable dose and the radon concentration should therefore be monitored. The high humidity in natural caves may impair the use of some measuring devices. Therefore, different detection methods were compared (ZnS scintillation counters, E-PERM electret ionisation chambers, cellulose nitrate alpha-track dosimeters) to select the best procedure for long-term investigation. The LR-115 (Kodak) alpha-track dosimeters were insensitive to humidity and permitted to monitor a great number of places at the same time. Measurements have been carried out in the speleological and archaeological site of the Toirano's Caves (Savona, Liguria, Italy) and several points were monitored for two years. Radon concentration strongly depends on the site and changes during the year, due to the difference between internal and external temperature. The maximum dose commitment during the visitors tour, considering the average yearly value of radon concentration, was found to be between 1.5 and 4 microSv. It was found that no risk exists for visitors, but the evaluation of the dose absorbed by the guides and their classification according to the radiation protection law requires a complete monitoring of the average yearly concentration of radon and of the total time spent by each worker into the cave.

Long-term leaching tests with high ash fusion Maryland coal slag

DOE Office of Scientific and Technical Information (OSTI.GOV)

Browman, M.G.

The main objective of this project was to investigate the potential environmental impact of the storage or disposal of coal gasification residues. In this regard, this investigation examined the quality of leachate produced during the long-term outdoor storage slag generated at the TVA 200-t/d Texaco gasifier in Muscle Shoals, Alabama. Evaluative laboratory extraction tests were also conducted on both the coarse and fine slag. Leachate quality was tracked in both the surface water and the water at depth after it percolated through the slag pile (leachate well water) by measuring pH and conductivity on a weekly basis and toxic tracemore » elements and other chemical species quarterly or at longer intervals. The major species observed in the leachate well water were Ca and Mg cations as well as sulfate anions. The average electrical conductivity measured in the leachate well water was 2503 {mu}mhos/cm. The measured pH decreased from an initial value of 8.2 and stabilized at about 7.1 with occasional excursions to values as low as 6.3 during dry periods. Concurrently, sulfate concentrations averaged 1083 mg/l with occasional peaks as high as 2600 mg/l. Fe and Mn concentrations measured in the leachate well waters averaged 2.0 and 1.68 mg/l, respectively. Concentrations of species for which Primary Maximum Contaminant Limits (MCLs) for public drinking water supplies have been established were generally below the primary limits with the exception of Se and F which exceeded the limits occasionally. Concentrations of Fe, Mn, sulfate, and total dissolved solids were markedly above the Secondary MCLs set for these species. 35 refs., 2 figs., 21 tabs.« less

Long-term effect of manure and fertilizer on soil organic carbon pools in dryland farming in northwest China.

PubMed

Liu, Enke; Yan, Changrong; Mei, Xurong; Zhang, Yanqing; Fan, Tinglu

2013-01-01

An understanding of the dynamics of soil organic carbon (SOC) as affected by farming practices is imperative for maintaining soil productivity and mitigating global warming. The objectives of this study were to investigate the effects of long-term fertilization on SOC and SOC fractions for the whole soil profile (0-100 cm) in northwest China. The study was initiated in 1979 in Gansu, China and included six treatments: unfertilized control (CK), nitrogen fertilizer (N), nitrogen and phosphorus (P) fertilizers (NP), straw plus N and P fertilizers (NP+S), farmyard manure (FYM), and farmyard manure plus N and P fertilizers (NP+FYM). Results showed that SOC concentration in the 0-20 cm soil layer increased with time except in the CK and N treatments. Long-term fertilization significantly influenced SOC concentrations and storage to 60 cm depth. Below 60 cm, SOC concentrations and storages were statistically not significant between all treatments. The concentration of SOC at different depths in 0-60 cm soil profile was higher under NP+FYM follow by under NP+S, compared to under CK. The SOC storage in 0-60 cm in NP+FYM, NP+S, FYM and NP treatments were increased by 41.3%, 32.9%, 28.1% and 17.9%, respectively, as compared to the CK treatment. Organic manure plus inorganic fertilizer application also increased labile soil organic carbon pools in 0-60 cm depth. The average concentration of particulate organic carbon (POC), dissolved organic carbon (DOC) and microbial biomass carbon (MBC) in organic manure plus inorganic fertilizer treatments (NP+S and NP+FYM) in 0-60 cm depth were increased by 64.9-91.9%, 42.5-56.9%, and 74.7-99.4%, respectively, over the CK treatment. The POC, MBC and DOC concentrations increased linearly with increasing SOC content. These results indicate that long-term additions of organic manure have the most beneficial effects in building carbon pools among the investigated types of fertilization.

Estimation of daily PM10 concentrations in Italy (2006-2012) using finely resolved satellite data, land use variables and meteorology.

PubMed

Stafoggia, Massimo; Schwartz, Joel; Badaloni, Chiara; Bellander, Tom; Alessandrini, Ester; Cattani, Giorgio; De' Donato, Francesca; Gaeta, Alessandra; Leone, Gianluca; Lyapustin, Alexei; Sorek-Hamer, Meytar; de Hoogh, Kees; Di, Qian; Forastiere, Francesco; Kloog, Itai

2017-02-01

Health effects of air pollution, especially particulate matter (PM), have been widely investigated. However, most of the studies rely on few monitors located in urban areas for short-term assessments, or land use/dispersion modelling for long-term evaluations, again mostly in cities. Recently, the availability of finely resolved satellite data provides an opportunity to estimate daily concentrations of air pollutants over wide spatio-temporal domains. Italy lacks a robust and validated high resolution spatio-temporally resolved model of particulate matter. The complex topography and the air mixture from both natural and anthropogenic sources are great challenges difficult to be addressed. We combined finely resolved data on Aerosol Optical Depth (AOD) from the Multi-Angle Implementation of Atmospheric Correction (MAIAC) algorithm, ground-level PM 10 measurements, land-use variables and meteorological parameters into a four-stage mixed model framework to derive estimates of daily PM 10 concentrations at 1-km2 grid over Italy, for the years 2006-2012. We checked performance of our models by applying 10-fold cross-validation (CV) for each year. Our models displayed good fitting, with mean CV-R2=0.65 and little bias (average slope of predicted VS observed PM 10 =0.99). Out-of-sample predictions were more accurate in Northern Italy (Po valley) and large conurbations (e.g. Rome), for background monitoring stations, and in the winter season. Resulting concentration maps showed highest average PM 10 levels in specific areas (Po river valley, main industrial and metropolitan areas) with decreasing trends over time. Our daily predictions of PM 10 concentrations across the whole Italy will allow, for the first time, estimation of long-term and short-term effects of air pollution nationwide, even in areas lacking monitoring data. Copyright © 2016 Elsevier Ltd. All rights reserved.

Catchment chemostasis revisited: water quality responds differently to variations in weather and climate

NASA Astrophysics Data System (ADS)

Godsey, Sarah; Kirchner, James

2017-04-01

Solute concentrations in streamflow typically vary systematically with stream discharge, and the resulting concentration-discharge relationships are important signatures of catchment (bio)geochemical processes. Solutes derived from mineral weathering often exhibit decreasing concentrations with increasing flows, suggesting dilution of a kinetically limited weathering flux by a variable flux of water. However, Godsey et al. (2009) showed that concentration-discharge relationships of weathering-derived solutes in 59 headwater catchments were much flatter than this simple dilution model would predict. Instead, their analysis showed that these catchments behaved almost like chemostats, with rates of solute production and/or mobilization that were nearly proportional to water fluxes, on both event and inter-annual time scales. Here we re-examine these findings using data from roughly 1000 catchments, ranging from ˜10 to >1,000,000 km2 in drainage area, and spanning a wide range of lithologic and climatic settings. Concentration-discharge relationships among this much larger set of much larger catchments are broadly consistent with the chemostatic behavior described by Godsey et al. (2009). Among these same catchments, however, site-to-site variations in mean concentrations are strongly (negatively) correlated with long-term average precipitation and discharge, suggesting strong dilution of stream concentrations under long-term leaching of the critical zone. The picture that emerges is one in which, on event and inter-annual time scales, stream solute concentrations are chemostatically buffered by groundwater storage and fast chemical reactions (such as ion exchange), but on much longer time scales, the catchment's chemostatic "set point" is determined by climatically driven critical zone evolution. Examples illustrating the different influences of (short-term) weather and (long-term) climate on water quality will be presented, and their implications will be discussed. Godsey, S.E., J.W. Kirchner and D.W. Clow, Concentration-discharge relationships reflect chemostatic characteristics of US catchments, Hydrological Processes, 23, 1844-1864, 2009.

Regional forecast model for the Olea pollen season in Extremadura (SW Spain).

PubMed

Fernández-Rodríguez, Santiago; Durán-Barroso, Pablo; Silva-Palacios, Inmaculada; Tormo-Molina, Rafael; Maya-Manzano, José María; Gonzalo-Garijo, Ángela

2016-10-01

The olive tree (Olea europaea) is a predominantly Mediterranean anemophilous species. The pollen allergens from this tree are an important cause of allergic problems. Olea pollen may be relevant in relation to climate change, due to the fact that its flowering phenology is related to meteorological parameters. This study aims to investigate airborne Olea pollen data from a city on the SW Iberian Peninsula, to analyse the trends in these data and their relationships with meteorological parameters using time series analysis. Aerobiological sampling was conducted from 1994 to 2013 in Badajoz (SW Spain) using a 7-day Hirst-type volumetric sampler. The main Olea pollen season lasted an average of 34 days, from May 4th to June 7th. The model proposed to forecast airborne pollen concentrations, described by one equation. This expression is composed of two terms: the first term represents the resilience of the pollen concentration trend in the air according to the average concentration of the previous 10 days; the second term was obtained from considering the actual pollen concentration value, which is calculated based on the most representative meteorological variables multiplied by a fitting coefficient. Due to the allergenic characteristics of this pollen type, it should be necessary to forecast its short-term prevalence using a long record of data in a city with a Mediterranean climate. The model obtained provides a suitable level of confidence to forecast Olea airborne pollen concentration.

Regional forecast model for the Olea pollen season in Extremadura (SW Spain)

NASA Astrophysics Data System (ADS)

Fernández-Rodríguez, Santiago; Durán-Barroso, Pablo; Silva-Palacios, Inmaculada; Tormo-Molina, Rafael; Maya-Manzano, José María; Gonzalo-Garijo, Ángela

2016-10-01

The olive tree ( Olea europaea) is a predominantly Mediterranean anemophilous species. The pollen allergens from this tree are an important cause of allergic problems. Olea pollen may be relevant in relation to climate change, due to the fact that its flowering phenology is related to meteorological parameters. This study aims to investigate airborne Olea pollen data from a city on the SW Iberian Peninsula, to analyse the trends in these data and their relationships with meteorological parameters using time series analysis. Aerobiological sampling was conducted from 1994 to 2013 in Badajoz (SW Spain) using a 7-day Hirst-type volumetric sampler. The main Olea pollen season lasted an average of 34 days, from May 4th to June 7th. The model proposed to forecast airborne pollen concentrations, described by one equation. This expression is composed of two terms: the first term represents the resilience of the pollen concentration trend in the air according to the average concentration of the previous 10 days; the second term was obtained from considering the actual pollen concentration value, which is calculated based on the most representative meteorological variables multiplied by a fitting coefficient. Due to the allergenic characteristics of this pollen type, it should be necessary to forecast its short-term prevalence using a long record of data in a city with a Mediterranean climate. The model obtained provides a suitable level of confidence to forecast Olea airborne pollen concentration.

The role of long-range transport and domestic emissions in determining atmospheric secondary inorganic particle concentrations across the UK

NASA Astrophysics Data System (ADS)

Vieno, M.; Heal, M. R.; Hallsworth, S.; Famulari, D.; Doherty, R. M.; Dore, A. J.; Tang, Y. S.; Braban, C. F.; Leaver, D.; Sutton, M. A.; Reis, S.

2013-12-01

Surface concentrations of secondary inorganic particle components over the UK have been analysed for 2001-2010 using the EMEP4UK regional atmospheric chemistry transport model. In early 2003 an episode of substantially elevated surface concentrations of ammonium nitrate was measured across the UK by the AGANET network. The EMEP4UK model was able accurately to represent both the long-term decadal surface concentrations and the episode in 2003. The latter was identified as consisting of three separate episodes, each of less than 1 month duration, in February, March and April. The primary cause of the elevated nitrate levels across the UK was meteorological, a persistent high pressure system, but whose varying location impacted the relative importance of transboundary vs. domestic emissions. Whilst long-range transport dominated the elevated nitrate in February, in contrast it was domestic emissions that mainly contributed to the March episode, and for the April episode both domestic emissions and long-range transport contributed. A prolonged episode such as the one in early 2003 can have substantial impact on annual average concentrations. The episode led to annual concentration differences at the regional scale of similar magnitude to those driven by long-term changes in precursor emissions over the full decade investigated here. The results demonstrate that a substantial part of the UK, particularly the south and south-east, may be close to or actually exceeding annual mean limit values because of import of inorganic aerosol components from continental Europe under specific conditions. The results reinforce the importance of employing multiple year simulations in the assessment of emissions reduction scenarios on PM concentrations and the need for international agreements to address the transboundary component of air pollution.

Colorectal Cancer and Long-Term Exposure to Trihalomethanes in Drinking Water: A Multicenter Case-Control Study in Spain and Italy.

PubMed

Villanueva, Cristina M; Gracia-Lavedan, Esther; Bosetti, Cristina; Righi, Elena; Molina, Antonio José; Martín, Vicente; Boldo, Elena; Aragonés, Nuria; Perez-Gomez, Beatriz; Pollan, Marina; Acebo, Ines Gomez; Altzibar, Jone M; Zabala, Ana Jiménez; Ardanaz, Eva; Peiró, Rosana; Tardón, Adonina; Chirlaque, Maria Dolores; Tavani, Alessandra; Polesel, Jerry; Serraino, Diego; Pisa, Federica; Castaño-Vinyals, Gemma; Espinosa, Ana; Espejo-Herrera, Nadia; Palau, Margarita; Moreno, Victor; La Vecchia, Carlo; Aggazzotti, Gabriella; Nieuwenhuijsen, Mark J; Kogevinas, Manolis

2017-01-01

Evidence on the association between colorectal cancer and exposure to disinfection by-products in drinking water is inconsistent. We assessed long-term exposure to trihalomethanes (THMs), the most prevalent group of chlorination by-products, to evaluate the association with colorectal cancer. A multicenter case-control study was conducted in Spain and Italy in 2008-2013. Hospital-based incident cases and population-based (Spain) and hospital-based (Italy) controls were interviewed to ascertain residential histories, type of water consumed in each residence, frequency and duration of showering/bathing, and major recognized risk factors for colorectal cancer. We estimated adjusted odds ratios (OR) for colorectal cancer in association with quartiles of estimated average lifetime THM concentrations in each participant's residential tap water (micrograms/liter; from age 18 to 2 years before the interview) and estimated average lifetime THM ingestion from drinking residential tap water (micrograms/day). We analyzed 2,047 cases and 3,718 controls. Median values (ranges) for average lifetime residential tap water concentrations of total THMs, chloroform, and brominated THMs were 30 (0-174), 17 (0-63), and 9 (0-145) μg/L, respectively. Total THM concentration in residential tap water was not associated with colorectal cancer (OR = 0.92, 95% CI: 0.66, 1.28 for highest vs. lowest quartile), but chloroform concentrations were inversely associated (OR = 0.31, 95% CI: 0.24, 0.41 for highest vs. lowest quartile). Brominated THM concentrations showed a positive association among men in the highest versus the lowest quartile (OR = 1.43, 95% CI: 0.83, 2.46). Patterns of association were similar for estimated average THM ingestion through residential water consumption. We did not find clear evidence of an association between detailed estimates of lifetime total THM exposure and colorectal cancer in our large case-control study population. Negative associations with chloroform concentrations and ingestion suggest differences among specific THMs, but these findings should be confirmed in other study populations. Citation: Villanueva CM, Gracia-Lavedan E, Bosetti C, Righi E, Molina AJ, Martín V, Boldo E, Aragonés N, Perez-Gomez B, Pollan M, Gomez Acebo I, Altzibar JM, Jiménez Zabala A, Ardanaz E, Peiró R, Tardón A, Chirlaque MD, Tavani A, Polesel J, Serraino D, Pisa F, Castaño-Vinyals G, Espinosa A, Espejo-Herrera N, Palau M, Moreno V, La Vecchia C, Aggazzotti G, Nieuwenhuijsen MJ, Kogevinas M. 2017. Colorectal cancer and long-term exposure to trihalomethanes in drinking water: a multicenter case---control study in Spain and Italy. Environ Health Perspect 125:56-65; http://dx.doi.org/10.1289/EHP155.

Colorectal Cancer and Long-Term Exposure to Trihalomethanes in Drinking Water: A Multicenter Case–Control Study in Spain and Italy

PubMed Central

Villanueva, Cristina M.; Gracia-Lavedan, Esther; Bosetti, Cristina; Righi, Elena; Molina, Antonio José; Martín, Vicente; Boldo, Elena; Aragonés, Nuria; Perez-Gomez, Beatriz; Pollan, Marina; Acebo, Ines Gomez; Altzibar, Jone M.; Zabala, Ana Jiménez; Ardanaz, Eva; Peiró, Rosana; Tardón, Adonina; Chirlaque, Maria Dolores; Tavani, Alessandra; Polesel, Jerry; Serraino, Diego; Pisa, Federica; Castaño-Vinyals, Gemma; Espinosa, Ana; Espejo-Herrera, Nadia; Palau, Margarita; Moreno, Victor; La Vecchia, Carlo; Aggazzotti, Gabriella; Nieuwenhuijsen, Mark J; Kogevinas, Manolis

2016-01-01

Background: Evidence on the association between colorectal cancer and exposure to disinfection by-products in drinking water is inconsistent. Objectives: We assessed long-term exposure to trihalomethanes (THMs), the most prevalent group of chlorination by-products, to evaluate the association with colorectal cancer. Methods: A multicenter case–control study was conducted in Spain and Italy in 2008–2013. Hospital-based incident cases and population-based (Spain) and hospital-based (Italy) controls were interviewed to ascertain residential histories, type of water consumed in each residence, frequency and duration of showering/bathing, and major recognized risk factors for colorectal cancer. We estimated adjusted odds ratios (OR) for colorectal cancer in association with quartiles of estimated average lifetime THM concentrations in each participant’s residential tap water (micrograms/liter; from age 18 to 2 years before the interview) and estimated average lifetime THM ingestion from drinking residential tap water (micrograms/day). Results: We analyzed 2,047 cases and 3,718 controls. Median values (ranges) for average lifetime residential tap water concentrations of total THMs, chloroform, and brominated THMs were 30 (0–174), 17 (0–63), and 9 (0–145) μg/L, respectively. Total THM concentration in residential tap water was not associated with colorectal cancer (OR = 0.92, 95% CI: 0.66, 1.28 for highest vs. lowest quartile), but chloroform concentrations were inversely associated (OR = 0.31, 95% CI: 0.24, 0.41 for highest vs. lowest quartile). Brominated THM concentrations showed a positive association among men in the highest versus the lowest quartile (OR = 1.43, 95% CI: 0.83, 2.46). Patterns of association were similar for estimated average THM ingestion through residential water consumption. Conclusions: We did not find clear evidence of an association between detailed estimates of lifetime total THM exposure and colorectal cancer in our large case–control study population. Negative associations with chloroform concentrations and ingestion suggest differences among specific THMs, but these findings should be confirmed in other study populations. Citation: Villanueva CM, Gracia-Lavedan E, Bosetti C, Righi E, Molina AJ, Martín V, Boldo E, Aragonés N, Perez-Gomez B, Pollan M, Gomez Acebo I, Altzibar JM, Jiménez Zabala A, Ardanaz E, Peiró R, Tardón A, Chirlaque MD, Tavani A, Polesel J, Serraino D, Pisa F, Castaño-Vinyals G, Espinosa A, Espejo-Herrera N, Palau M, Moreno V, La Vecchia C, Aggazzotti G, Nieuwenhuijsen MJ, Kogevinas M. 2017. Colorectal cancer and long-term exposure to trihalomethanes in drinking water: a multicenter case–––control study in Spain and Italy. Environ Health Perspect 125:56–65; http://dx.doi.org/10.1289/EHP155 PMID:27383820

Modeling 13C discrimination in Tree Rings

NASA Astrophysics Data System (ADS)

Berninger, Frank; Sonninen, Eloni; Aalto, Tuula; Lloyd, Jon

2000-03-01

Annual variations from 1877 to 1995 in tree-ring α-cellulose 13C/12C isotopic ratios for four subarctic Pinus sylvestris trees were determined, and, in conjunction with a recent record of atmospheric 13CO2/12CO2 ratios, the historical pattern of photosynthetic isotope discrimination, Δ13C, was evaluated. Year-to-year variability in Δ13C has been as much as 1.5‰ with the period 1900-1920 showing an extended period of unusually high photosynthetic discriminations. The summers during these years were, on average, unusually cold. Since 1920 a long term trend of increasing Δ13C of ˜0.016‰yr-1 is inferred. We compared measured Δ13C with those predicted on the basis of the theoretical relationship between Δ13C and the ratio of substomatal to ambient CO2 concentration, Ci/Ca using mechanistic equations for chloroplast biochemistry coupled with a stomatal conductance model. Two variations of a nonlinear optimal-regulation stomatal conductance model were compared. Although both models were based on the assumption that stomata serve to minimize the average transpiration rate for a given average rate of CO2 assimilation, one version of the model incorporated reductions in stomatal conductance in response to recent increases in atmospheric CO2 concentrations and the other did not. The CO2 sensitive stomatal model failed to describe the long-term increase in 13C discrimination, especially after 1950. The insensitive model gave good agreement, suggesting that an observed increase in subarctic Pinus sylvestris Δ13C since 1920 is attributable to recent increases in atmospheric CO2 concentrations with subsequent increases in the ratio of substomatal to ambient CO2 concentrations. The model was also capable of accounting for high frequency (year-to-year) variations in Δ13C, these differences being attributable to year-to-year fluctuations in the average leaf-to-air vapor pressure difference affecting stomatal conductance and hence Ci/Ca.

Chemical climatology of the southeastern United States, 1999-2013

NASA Astrophysics Data System (ADS)

Hidy, G. M.; Blanchard, C. L.; Baumann, K.; Edgerton, E.; Tanenbaum, S.; Shaw, S.; Knipping, E.; Tombach, I.; Jansen, J.; Walters, J.

2014-06-01

A series of experiments (the Southern Oxidant and Aerosol Study-SOAS) took place in central Alabama in June-July 2013 as part of the broader Southern Atmosphere Study (SAS). These projects were aimed at studying oxidant photochemistry and formation and impacts of aerosols at a detailed process level in a location where high biogenic organic vapor emissions interact with anthropogenic emissions, and the atmospheric chemistry occurs in a subtropical climate in North America. The majority of the ground-based experiments were located at the Southeastern Aerosol Research and Characterization (SEARCH) Centreville (CTR) site near Brent, Alabama, where extensive, unique aerometric measurements of meteorology, trace gases and particles have been made from the early 1990s through 2013. The SEARCH network data permits a characterization of temporal and spatial context of the SOAS findings. The long-term measurements show that the SOAS experiments took place during the second wettest and coolest year in the 2000-2013 period, with lower than average solar radiation. The pollution levels at CTR and other SEARCH sites were the lowest since full measurements began in 1999. This dataset provides a perspective for the SOAS program in terms of long-term average chemistry (chemical climatology) and short-term comparisons of summer average spatial variability across the Southeast at high temporal (hourly) resolution. Changes in anthropogenic gas and particle emissions between 1999 and 2013, account for the decline in pollutant concentrations at the monitoring sites in the region. The long-term and short-term data provide an opportunity to contrast SOAS results with temporally and spatially variable conditions in support for the development of tests for the robustness of SOAS findings.

Nebraska's groundwater legacy: Nitrate contamination beneath irrigated cropland

PubMed Central

Exner, Mary E; Hirsh, Aaron J; Spalding, Roy F

2014-01-01

A 31 year record of ∼44,000 nitrate analyses in ∼11,500 irrigation wells was utilized to depict the decadal expansion of groundwater nitrate contamination (N ≥ 10 mg/L) in the irrigated corn-growing areas of eastern and central Nebraska and analyze long-term nitrate concentration trends in 17 management areas (MAs) subject to N fertilizer and budgeting requirements. The 1.3 M contaminated hectares were characterized by irrigation method, soil drainage, and vadose zone thickness and lithology. The areal extent and growth of contaminated groundwater in two predominately sprinkler-irrigated areas was only ∼20% smaller beneath well-drained silt loams with thick clayey-silt unsaturated layers and unsaturated thicknesses >15 m (400,000 ha and 15,000 ha/yr) than beneath well and excessively well-drained soils with very sandy vadose zones (511,000 ha and 18,600 ha/yr). Much slower expansion (3700 ha/yr) occurred in the 220,000 contaminated hectares in the central Platte valley characterized by predominately gravity irrigation on thick, well-drained silt loams above a thin (∼5.3 m), sandy unsaturated zone. The only reversals in long-term concentration trends occurred in two MAs (120,500 ha) within this contaminated area. Concentrations declined 0.14 and 0.20 mg N/L/yr (p < 0.02) to ∼18.3 and 18.8 mg N/L, respectively, during >20 years of management. Average annual concentrations in 10 MAs are increasing (p < 0.05) and indicate that average nitrate concentrations in leachates below the root zone and groundwater concentrations have not yet reached steady state. While management practices likely have slowed increases in groundwater nitrate concentrations, irrigation and nutrient applications must be more effectively controlled to retain nitrate in the root zone. PMID:25558112

Long-term follow-up of shoulder hemiarthroplasty for glenohumeral osteoarthritis.

PubMed

Levine, William N; Fischer, Charla R; Nguyen, Duong; Flatow, Evan L; Ahmad, Christopher S; Bigliani, Louis U

2012-11-21

There is major controversy surrounding the use of hemiarthroplasty as compared with total shoulder arthroplasty for glenohumeral osteoarthritis, and long-term clinical outcomes of hemiarthroplasty are lacking. Of a cohort of thirty patients (thirty-one shoulders) who were treated with hemiarthroplasty for glenohumeral osteoarthritis and followed longitudinally at our institution, twenty-five were available for long-term follow-up; five died, and one refused to participate. Three of the five patients who died had revision arthroplasty before death, and the data from those three were therefore included in the final follow-up (final follow-up data therefore included twenty-seven patients and twenty-eight shoulders). Follow-up through phone conversations and postal mail surveys included the following: Short Form-36, American Shoulder and Elbow Surgeons (ASES) shoulder outcome score, EuroQol, Simple Shoulder Test, modified Neer Score, and a unique, validated self-administered range-of-motion questionnaire. Correlations between clinical outcome and age, type of glenoid wear, and cause of osteoarthritis were determined. The average follow-up was 17.2 years (range, thirteen to twenty-one years). There were eight revisions (three of fifteen shoulders with concentric glenoids, and five of sixteen shoulders with eccentric glenoids). For those shoulders not revised, the average ASES score was 70.54 (range, 36.67 to 91.67). Overall, active shoulder forward elevation and external rotation with the arm at 90° of abduction increased from 104° preoperatively to 141.8° (range, 45° to 180°) and 20.7° to 61.0° (range, 30° to 90°), respectively (p < 0.05), at the time of final follow-up. Of those who required revision arthroplasty, the average patient age at the time of the index procedure was 51.0 years (range, twenty-six to eighty-one years), while those not requiring revision averaged 57.1 years (range, twenty-seven to sixty-three years). The overall Neer satisfaction rating was 25%. The average Neer score and Neer rating for unrevised cases were significantly higher for concentric glenoid wear compared with eccentric glenoid wear (p = 0.015 and p = 0.001, respectively). Patients who had concentric glenoid wear had higher EuroQol scores (p = 0.020). The average Neer scores were 65.29 (range, forty-seven to seventy-eight) for primary osteoarthritis and 54.46 (range, forty to seventy-seven) for secondary osteoarthritis (p = 0.036). Only 25% of patients with glenohumeral osteoarthritis treated with shoulder hemiarthroplasty are satisfied with their outcome at an average of seventeen years after the operation. Patients with concentric glenoid wear and primary osteoarthritis have better outcomes than those with eccentric glenoid wear and secondary osteoarthritis do, but patients in both groups experienced deterioration of results over time. Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Effects of long-term fixed orthodontic treatment on salivary nickel and chromium levels: a 1-year prospective cohort study.

PubMed

Amini, Fariborz; Rakhshan, Vahid; Mesgarzadeh, Nasim

2012-12-01

Effect of long-term orthodontic treatment on salivary nickel and chromium has not been quite assessed except in few retrospective studies with controversial results. The aim of this prospective study was to measure salivary levels of these ions during 1 year of orthodontic treatment. Saliva samples were collected from 20 orthodontic patients, before treatment (control) and 6 and 12 months later. Nickel and chromium concentrations were determined using atomic absorption spectrophotometry. Data were analyzed using one- and two-way repeated-measures ANOVA, Bonferroni, Friedman (α = 0.05), and Wilcoxon signed-ranks tests (α = 0.016). Average nickel level changed from 9.75 ± 5.02 to 10.37 ± 6.94 and then to 8.32 ± 4.36 μg/L in 1 year. Average chromium concentration changed from 3.86 ± 1.34 to 4.6 ± 6.11 and then to 2.04 ± 1.66 μg/L. Alterations in nickel values were not statistically significant [P = 0.468 (ANOVA)], but fluctuations in chromium levels were [P = 0.021 (Friedman)]. The decrease in chromium concentration after 12 months was significant compared to the control [P = 0.004 (Wilcoxon)]. Although slightly increased after 6 months, the concentration of both ions dropped to levels slightly lower than the control groups after 12 months.

Long term (1987-2012) trends in water chemistry of acid sensitive Swedish lakes

NASA Astrophysics Data System (ADS)

Futter, Martyn; Valinia, Salar; Fölster, Jens

2014-05-01

Acidification of surface waters is a serious concern in Sweden. During the 1970s and 1980s, many surface waters in Sweden were acidified by long-range pollution. Legislated emissions reductions have led to the recovery of many water bodies but today, there are concerns about the possibility of re-acidification. Sweden is committed to a goal of natural acidification only (i.e. no anthropogenic acidification). Here, we present long term (1987-2012) trends in strong acid anion, base cation, organic carbon and alkalinity measurements. Lakes are defined as acidified in Sweden if pH is more than 0.4 units less than a reference (1860) pH estimated using MAGIC, a widely used process-based model of acidification. Using this criteria, many acid sensitive Swedish lakes are still acidified. A changing climate and more intensive forest harvesting may further delay the recovery from acidification. Average measured alkalinity in the 38 lakes presented here was <= 0.02 mekv/l between 2000-2012. Strong acid anion concentrations declined, primarily as a result of declines in sulfate. Chloride is now the dominant anion in many of these lakes. Base cations concentrations have declined less rapidly, leading to an increase in charge balance ANC. This increase in charge balance ANC has not been matched by an increase in measured alkalinity. Total organic carbon concentrations have increased significantly in many of these lakes, to the point where modeled organic acidity is now approximately equal to inorganic acidity. While the results presented here conform to acidification theory, they illustrate the value of long-term monitoring for assessing the effects of pollutant reduction measures, identifying new threats to water quality and corroborating model results. Most importantly, the long-term monitoring results presented here can be an important tool for informing environmental policy.

Sediment Flux of Particulate Organic Phosphorus in the Open Black Sea

NASA Astrophysics Data System (ADS)

Parkhomenko, A. V.; Kukushkin, A. S.

2018-03-01

The interannual variation of the monthly average (weighted average) concentrations of particulate organic phosphorus (PPOM) in the photosynthetic layer, oxycline, redox zone, and H2S zone in the open Black Sea is estimated based on long-term observation data. The suspension sedimentation rates from the studied layers are assessed using model calculations and published data. The annual variation of PPOM sediment fluxes from the photosynthetic layer, oxycline, redox zone, and upper H2S zone to the anaerobic zone of the sea and the correspondingly annual average values are estimated for the first time. A regular decrease in the PPOM annual average flux with depth in the upper active layer is demonstrated. A correlation between the annual average values of PPOM sediment flux from the photosynthetic layer and ascending phosphate flux to this layer is shown, which suggests their balance in the open sea. The results are discussed in terms of the phosphorus biogeochemical cycle and the concept of new and regenerative primary production in the open Black Sea.

Relationship between cognition function and hippocampus structure after long-term microwave exposure.

PubMed

Zhao, Li; Peng, Rui Yun; Wang, Shui Ming; Wang, Li Feng; Gao, Ya Bing; Dong, Ji; Li, Xiang; Su, Zhen Tao

2012-04-01

To analyze the effects of long-term microwave exposure on hippocampal structure and function in the rat. Experiments were performed on 184 male Wistar rats (three exposure groups and a sham group). Microwaves were applied daily for 6 min over 1 month at average power densities of 2.5, 5, and 10 mW/cm2. Learning and memory abilities were assessed by Morris water maze. High performance liquid chromatography was used to detect neurotransmitter concentrations in the hippocampus. Hippocampal structures were observed by histopathological analysis. Following long-term microwave exposure there was a significant decrease in learning and memory activity in the 7 d, 14 d, and 1 m in all three microwave exposure groups. Neurotransmitter concentrations of four amino acids (glutamate, aspartic acid, glycine, and gamma-aminobutyric acid) in hippocampus were increased in the 2.5 and 5 mW/cm2 groups and decreased in the 10 mW/cm2 group. There was evidence of neuronal degeneration and enlarged perivascular spaces in the hippocampus in the microwave exposure groups. Further, mitochondria became swollen and cristae were disordered. The rough endoplasmic reticulum exhibited sacculated distension and there was a decrease in the quantity of synaptic vesicles. These data suggest that the hippocampus can be injured by long-term microwave exposure, which might result in impairment of cognitive function due to neurotransmitter disruption.

Long Term Trend Analysis and Assessment of Water Quality in the Penchala River, Malaysia

NASA Astrophysics Data System (ADS)

Chow, M. F.; Haris, H. B.; Mohd Sidek, L. B.

2014-12-01

Rapid urban expansion produces negative impacts on the natural environment, especially river water quality. Studies assessing long term changes of water quality have been recognized as a key tool for understanding ongoing processes in watersheds and for providing an essential background for evaluation of rapid changes within industrialized and populated urban areas. Unfortunately, only limited studies are available for developing countries such as Malaysia. Thus, a long term study was conducted to evaluate water quality trends at Pencala river basin that has undergone extensive land use changes related to industrial, agricultural and urban activities. Fifteen physical and chemical variables were analysed in river water samples collected every month over a period of 13 years, between 1997 and 2009. The trend study was performed using the Mann-Kendall Seasonal test and the Sen's Slope estimator. Results revealed that most water quality parameters showed a downward trend for yearly average concentration. The water quality index (WQI) for Pencala River was improved from Class V to Class IV, according to National Water Quality Standards for Malaysia. BOD, COD, NH3-N and SS show trends toward decreasing concentrations over time. The improvements seen in water quality appear to be the result of improved wastewater treatment and other water quality improvement efforts achieved through government initiative. Continued long-term and high frequency monitoring is necessary to establish plans and policies for effective water resources management.

Long-term increases in young-of-the-year growth of Arctic cisco Coregonus autumnalis and environmental influences

USGS Publications Warehouse

von Biela, Vanessa R.; Zimmerman, Christian E.; Moulton, L. L.

2011-01-01

Arctic cisco Coregonus autumnalis young-of-year (YOY) growth was used as a proxy to examine the long-term response of a high-latitude fish population to changing climate from 1978 to 2004. YOY growth increased over time (r2 = 0·29) and was correlated with monthly averages of the Arctic oscillation index, air temperature, east wind speed, sea-ice concentration and river discharge with and without time lags. Overall, the most prevalent correlates to YOY growth were sea-ice concentration lagged 1 year (significant correlations in 7 months; r2 = 0·14-0·31) and Mackenzie River discharge lagged 2 years (significant correlations in 8 months; r2 = 0·13-0·50). The results suggest that decreased sea-ice concentrations and increased river discharge fuel primary production and that life cycles of prey species linking increased primary production to fish growth are responsible for the time lag. Oceanographic studies also suggest that sea ice concentration and fluvial inputs from the Mackenzie River are key factors influencing productivity in the Beaufort Sea. Future research should assess the possible mechanism relating sea ice concentration and river discharge to productivity at upper trophic levels.

Longitudinal Effects of Air Pollution on Exhaled Nitric Oxide: The Children’s Health Study

PubMed Central

Berhane, Kiros; Zhang, Yue; Salam, Muhammad T.; Eckel, Sandrah P.; Linn, William S.; Rappaport, Edward B.; Bastain, Theresa M; Lurmann, Fred; Gilliland, Frank D.

2015-01-01

OBJECTIVES To assess the effects of long-term variations in ambient air pollutants on longitudinal changes in exhaled nitric oxide (FeNO), a potentially useful biomarker of eosinophilic airway inflammation, based on data from the southern California Children’s Health Study. METHODS Based on a cohort of 1,211 schoolchildren from 8 Southern California communities with FeNO measurements in 2006/07 and 2007/08, regression models adjusted for short-term effects of air pollution were fitted to assess the association between changes in annual long-term exposures and changes in FeNO. RESULTS Increases in annual average concentrations of 24-hr average NO2 and PM2.5 (scaled to the interquartile range (IQR) of 1.8 ppb and 2.4 μg/m3, respectively) were associated with a 2.29 ppb (CI=[0.36,4.21]; p =0.02) and a 4.94 ppb (CI=[1.44,8.47]; p = 0.005) increase in FeNO, respectively, after adjustments for short term effects of the respective pollutants. In contrast, changes in annual averages of PM10 and O3 were not significantly associated with changes in FeNO. These findings did not differ significantly by asthma status. CONCLUSIONS Changes in annual average exposure to current levels of ambient air pollutants are significantly associated with changes in FeNO levels in children, independent of short-term exposures and asthma status. Use of this biomarker in population-based epidemiologic research has great potential for assessing the impact of changing real world mixtures of ambient air pollutants on children’s respiratory health. PMID:24696513

Disinfection Byproducts in Drinking Water and Evaluation of Potential Health Risks of Long-Term Exposure in Nigeria.

PubMed

Benson, Nsikak U; Akintokun, Oyeronke A; Adedapo, Adebusayo E

2017-01-01

Levels of trihalomethanes (THMs) in drinking water from water treatment plants (WTPs) in Nigeria were studied using a gas chromatograph (GC Agilent 7890A with autosampler Agilent 7683B) equipped with electron capture detector (ECD). The mean concentrations of the trihalomethanes ranged from zero in raw water samples to 950  μ g/L in treated water samples. Average concentration values of THMs in primary and secondary disinfection samples exceeded the standard maximum contaminant levels. Results for the average THMs concentrations followed the order TCM > BDCM > DBCM > TBM. EPA-developed models were adopted for the estimation of chronic daily intakes (CDI) and excess cancer incidence through ingestion pathway. Higher average intake was observed in adults (4.52 × 10 -2  mg/kg-day), while the ingestion in children (3.99 × 10 -2  mg/kg-day) showed comparable values. The total lifetime cancer incidence rate was relatively higher in adults than children with median values 244 and 199 times the negligible risk level.

Average Temperatures in the Southwestern United States, 2000-2015 Versus Long-Term Average

EPA Pesticide Factsheets

This indicator shows how the average air temperature from 2000 to 2015 has differed from the long-term average (1895??2015). To provide more detailed information, each state has been divided into climate divisions, which are zones that share similar climate features. For more information: www.epa.gov/climatechange/science/indicators

Tritium concentrations in bees and honey at Los Alamos National Laboratory: 1979-1996

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fresquez, P.R.; Armstrong, D.R.; Pratt, L.H.

Honeybees are effective monitors of environmental pollution. The objective of this study was to summarize tritium ({sup 3}H) concentrations in bees and honey collected from within and around Los Alamos National Laboratory (LANL) over an 18-year period. Based on the long-term average, bees from nine out of eleven hives and honey from six out of eleven hives on LANL lands contained {sup 3}H that was significantly higher (p <0.05) than background. The highest average concentration of {sup 3}H in bees (435 pCi mL{sup -1}) collected over the years was from LANL`s Technical Area (TA) 54-a low-level radioactive waste disposal sitemore » (Area G). Similarly, the highest average concentration of {sup 3}H in honey (709 pCi mL{sup - 1}) was collected from a hive located near three {sup 3}H storage ponds at LANL TA-53. The average concentrations of {sup 3}H in bees and honey from background hives was 1.0 pCi mL{sup -1} and 1.5 pCi ML{sup -1}, respectively. Although the concentrations of 3H in bees and honey from most LANL and perimeter (White Rock/Pajarito Acres) areas were significantly higher than background, most areas, with the exception of TA-53 and TA-54, generally exhibited decreasing 3H concentrations over time.« less

SeaWiFS Third Anniversary Global Biosphere

NASA Technical Reports Server (NTRS)

2002-01-01

September 18,2000 is the third anniversary of the start of regular SeaWiFS operations of this remarkable planet called Earth. This SeaWiFS image is of the Global Biosphere depicting the ocean's long-term average phytoplankton chlorophyll concentration acquired between September 1997 and August 2000 combined with the SeaWiFS-derived Normalized Difference Vegetation Index (NDVI) over land during July 2000.

Long term (1997-2014) spatial and temporal variations in nitrogen in Dongting Lake, China

PubMed Central

Tian, Zebin; Zheng, Binghui; Wang, Lijing; Li, Liqiang; Wang, Xing; Li, Hong; Norra, Stefan

2017-01-01

In order to protect the water quality of Dongting Lake, it is significant to find out its nitrogen pollution characteristics. Using long-term monthly to seasonally data (1997–2014), we investigated the spatial and temporal variations in nitrogen in Dongting Lake, the second largest freshwater lake in China. The average concentrations of total nitrogen (TN) in the eastern, southern, and western parts of the lake were 1.77, 1.56, and 1.35 mg/L, respectively, in 2014. TN pollution was generally worse in the southern area than in the western area. Concentrations showed temporal variation, and were significantly higher during the dry season than during the wet season. Based on the concentration and growth rate of TN, three different stages were identified in the long term lake data, from 1997 to 2002, from 2003 to 2008, and from 2009 to 2014, during which the concentrations and the growth rate ranged from 1.09–1.51 mg/L and 22.09%-40.03%, 1.05–1.57 mg/L and -9.05%-7.74%, and 1.68–2.02 mg/L and 57.99%-60.41%, respectively. The main controls on the lake water TN concentrations were the quality and quantity of the lake inflows, spatial and temporal variations in hydrodynamic conditions within the lake (flow velocity, flow direction), and point and nonpoint inputs from human activities. Diffuse nutrient losses from agricultural land are a significant contributor. As a priority, the local government should aim to control the pollutant inputs from upstream and non-point nutrient losses from land. PMID:28166245

Assessment of long-term measurements of particulate matter and gaseous pollutants in South-East Mediterranean

NASA Astrophysics Data System (ADS)

Mouzourides, Petros; Kumar, Prashant; Neophytou, Marina K.-A.

2015-04-01

This work examines long-term measurements of major criteria pollutants concentrations in an urban station in South-Eastern Mediterranean, in Nicosia - Cyprus, which is susceptible both to transboundary air pollution transport from Sahara-dust events as well as to evaporative transport of sea-sprays. The work investigates in particular the role of such multi-scale contributions in the urban air quality measurements, which are important considerations in the assessment of the effectiveness of any mitigation policies implemented by regulatory authorities. Attention is drawn in the regional-scale component of the particulate matter concentrations (PM10; ≤10 μm in diameter) and its contribution in the local measurements. Hourly averaged data of CO, NOx and PM10 concentrations as well as of meteorological parameters were collected from the Air Quality Monitoring Station (AQMS) of the University of Cyprus over a period of more than 5 years (2008-13) and were analysed. Scanning Electron Microscope (SEM) was used to identify chemical characteristics of PM10 and to attribute it to possible sources. A total of 321 days over the entire period were found to exceed the daily limit value of 50 μg/m3 for PM10 concentrations which corresponds to ∼19% of the actual monitored time. Numerical simulations using the Dust REgional Atmospheric Model from Barcelona Supercomputing Center (BSC/DREAM) gave a strong indication that PM10 exceedances were associated with the high regional background dust concentrations during westerly winds. It was also found that despite the implementation of tighter regulations for vehicular and industrial emissions in Europe, the monthly average concentration values of criteria pollutants do not exhibit any falling trend.

Black Carbon Concentration from Worldwide Aerosol Robotic Network (AERONET)

NASA Technical Reports Server (NTRS)

Schuster, Greg; Dubovik, Oleg; Holben, Brent; Clothiaux, Eugene

2008-01-01

Worldwide black carbon concentration measurements are needed to assess the efficacy of the carbon emissions inventory and transport model output. This requires long-term measurements in many regions, as model success in one region or season does not apply to all regions and seasons. AERONET is an automated network of more than 180 surface radiometers located throughout the world. The sky radiance measurements obtained by AERONET are inverted to provide column-averaged aerosol refractive indices and size distributions for the AERONET database, which we use to derive column-averaged black carbon concentrations and specific absorptions that are constrained by the measured radiation field. This provides a link between AERONET sky radiance measurements and the elemental carbon concentration of transport models without the need for an optics module in the transport model. Knowledge of both the black carbon concentration and aerosol absorption optical depth (i.e., input and output of the optics module) will enable improvements to the transport model optics module.

Assessing the effects of oil sands related ozone precursor emissions on ambient ozone levels in the Alberta oil sands region, Canada

NASA Astrophysics Data System (ADS)

Cho, Sunny; Vijayaraghavan, Krish; Spink, David; Cosic, Biljana; Davies, Mervyn; Jung, Jaegun

2017-11-01

A study was undertaken to determine whether, and the extent to which, increased ground-level ozone (O3) precursor emissions from oil sands development have impacted ambient air quality in the north-eastern Alberta, Canada, over the period 1998 to 2012. Temporal trends in emissions of O3 precursors (NOx and VOC) and ambient air concentrations of O3 precursors, and O3 were examined using the Theil-Sen statistical analysis method. Statistically significant correlations between NOx emissions and ambient NOx concentrations were found mainly near surface (open-pit) mining areas where mine fleets are a large source of NOx emissions. No statistically significant trends in the 4th highest daily maximum 8-hr average O3 at any of the continuous and passive ambient air monitoring stations were found. A significant long-term decrease in monthly averaged O3 is observed at some ambient monitoring sites in summer. A visual examination of long-term variations in annual NOx and VOC emissions and annual 4th highest daily maximum 8-hr O3 concentrations does not reveal any indication of a correlation between O3 concentrations and O3 precursor emissions or ambient levels in the study area. Despite a significant increase in oil sands NOx emissions (8%/yr), there is no statistically significant increase in long-term O3 concentrations at any of monitoring stations considered. This suggests that there is surplus NOx available in the environment which results in a titration of ambient O3 in the areas that have ambient monitoring. The limited ambient O3 monitoring data distant from NOx emission sources makes it impossible to assess the impact of these increased O3 precursor levels on O3 levels on a regional scale. As a precautionary measure, the increasing oil sands development O3 precursor emissions would require that priority be given to the management of these emissions to prevent possible future O3 ambient air quality issues.

Long-term compliance with salt restriction assessed using the spot urine method in Japanese cardiology outpatients.

PubMed

Hirota, Shinichi; Sadanaga, Tsuneaki; Mitamura, Hideo; Fukuda, Keiichi

2013-12-01

The purpose of this study was to evaluate long-term compliance with salt restriction in Japanese cardiology outpatients assessed by spot urine measurements. A total of 466 patients (72 ± 10 years old, 216 females) who visited a cardiology outpatient clinic and were followed for at least 1 year were included in this study. Daily dietary salt intake was estimated based on the sodium and creatinine concentrations determined by spot urine at the time of enrollment, during an 8-26 week follow-up and at a long-term follow-up (>1 year). The average follow-up duration was 2.2 ± 0.6 (1.0-3.4) years after enrollment, and spot urines were collected 5.2 ± 2.8 times after 1 year. The baseline estimated salt excretion was 9.6 ± 2.7 g per day, which was reduced to 8.7 ± 2.3 g per day (P<0.01) at 8-26 weeks and remained unchanged at the long-term follow-up (8.9 ± 2.0 g per day, P = 0.36 vs. 8-26 weeks, P < 0.01 vs. baseline). The percent of patients who achieved an average salt excretion<6.0 g per day was unchanged from baseline (6.9% vs. 7.7%, P = 0.61). Among several variables (gender, age, body weight, salt excretion at enrollment) that might affect the incidence of salt excretion <6.0 g per day, salt excretion at baseline was the only determinant of successful salt restriction (P<0.01). In conclusion, compliance with salt restriction, assessed using a spot urine method, was maintained over the long term; however, achieving salt reduction to the level recommended by the guidelines remains a challenge.

IODINE CONTENT OF ENTERAL AND PARENTERAL NUTRITION SOLUTIONS.

PubMed

Willard, Devina L; Young, Lorraine S; He, Xuemei; Braverman, Lewis E; Pearce, Elizabeth N

2017-07-01

Iodine is essential for thyroid hormone synthesis, and iodine deficiency may result in thyroid disorders including goiter and hypothyroidism. Patients on long-term enteral nutrition (EN) or parenteral nutrition (PN) may be at risk for micronutrient deficiencies. The recommended daily allowance for iodine intake is 150 μg for nonpregnant adults. However, there is no current consensus among scientific societies regarding the quantity of iodine to be added in adult EN and PN formulations. The objective of this study was to determine the iodine content of U.S. adult enteral and parenteral nutrition solutions. This study also aimed to determine whether adult patients in the United States who are receiving long-term artificial nutrition may be at risk for iodine deficiency. Ten enteral nutrition solutions and 4 parenteral nutrition solutions were evaluated. The iodine contents of these solutions were measured spectrophotometrically and compared to the labeled contents. Measured and labeled EN iodine contents were similar (range 131-176 μg/L and 106-160 μg/L, respectively). In contrast, PN formulas were found to contain small, unlabeled amounts of iodine, averaging 27 μg/L. Typical fluid requirements are 30 to 40 mL/kg/day for adults receiving either total EN (TEN) or total PN (TPN). Adults on long-term TEN likely consume enough servings to meet their daily iodine requirements. However, patients on long-term TPN would require on average 5.6 L PN/day to meet the recommended daily allowance of iodine. This volume of PN is far in excess of typical consumption. Thus, U.S. patients requiring long-term TPN may be at risk for iodine deficiency. EN = enteral nutrition; PN = parenteral nutrition; TEN = total enteral nutrition; TPN = total parenteral nutrition; UIC = urinary iodine concentration.

Long-term climate and competition explain forest mortality patterns under extreme drought.

PubMed

Young, Derek J N; Stevens, Jens T; Earles, J Mason; Moore, Jeffrey; Ellis, Adam; Jirka, Amy L; Latimer, Andrew M

2017-01-01

Rising temperatures are amplifying drought-induced stress and mortality in forests globally. It remains uncertain, however, whether tree mortality across drought-stricken landscapes will be concentrated in particular climatic and competitive environments. We investigated the effects of long-term average climate [i.e. 35-year mean annual climatic water deficit (CWD)] and competition (i.e. tree basal area) on tree mortality patterns, using extensive aerial mortality surveys conducted throughout the forests of California during a 4-year statewide extreme drought lasting from 2012 to 2015. During this period, tree mortality increased by an order of magnitude, typically from tens to hundreds of dead trees per km 2 , rising dramatically during the fourth year of drought. Mortality rates increased independently with average CWD and with basal area, and they increased disproportionately in areas that were both dry and dense. These results can assist forest managers and policy-makers in identifying the most drought-vulnerable forests across broad geographic areas. © 2016 John Wiley & Sons Ltd/CNRS.

Air concentrations of /sup 239/Pu and /sup 240/Pu and potential radiation doses to persons living near Pu-contaminated areas in Palomares, Spain

DOE Office of Scientific and Technical Information (OSTI.GOV)

Iranzo, E.; Salvador, S.; Iranzo, C.E.

1987-04-01

On 17 January 1966, an accident during a refueling operation resulted in the destruction of an air force KC-135 tanker and a B-52 bomber carrying four thermonuclear weapons. Two weapons, whose parachutes opened, were found intact. The others experienced non-nuclear explosion with some burning and release of the fissile fuel at impact. Joint efforts by the United States and Spain resulted in remedial action and a long-term program to monitor the effectiveness of the cleanup. Air concentrations of /sup 239/Pu and /sup 240/Pu have been continuously monitored since the accident. The average annual air concentration for each location was usedmore » to estimate committed dose equivalents for individuals living and working around the air sampling stations. The average annual /sup 239/Pu and /sup 240/Pu air concentrations during the 15-y period corresponding to 1966-1980 and the potential committed dose equivalents for various tissues due to the inhalation of the /sup 239/Pu and /sup 240/Pu average annual air concentration during this period are shown and discussed in the report.« less

The influence of model spatial resolution on simulated ozone and fine particulate matter for Europe: implications for health impact assessments

NASA Astrophysics Data System (ADS)

Fenech, Sara; Doherty, Ruth M.; Heaviside, Clare; Vardoulakis, Sotiris; Macintyre, Helen L.; O'Connor, Fiona M.

2018-04-01

We examine the impact of model horizontal resolution on simulated concentrations of surface ozone (O3) and particulate matter less than 2.5 µm in diameter (PM2.5), and the associated health impacts over Europe, using the HadGEM3-UKCA chemistry-climate model to simulate pollutant concentrations at a coarse (˜ 140 km) and a finer (˜ 50 km) resolution. The attributable fraction (AF) of total mortality due to long-term exposure to warm season daily maximum 8 h running mean (MDA8) O3 and annual-average PM2.5 concentrations is then calculated for each European country using pollutant concentrations simulated at each resolution. Our results highlight a seasonal variation in simulated O3 and PM2.5 differences between the two model resolutions in Europe. Compared to the finer resolution results, simulated European O3 concentrations at the coarse resolution are higher on average in winter and spring (˜ 10 and ˜ 6 %, respectively). In contrast, simulated O3 concentrations at the coarse resolution are lower in summer and autumn (˜ -1 and ˜ -4 %, respectively). These differences may be partly explained by differences in nitrogen dioxide (NO2) concentrations simulated at the two resolutions. Compared to O3, we find the opposite seasonality in simulated PM2.5 differences between the two resolutions. In winter and spring, simulated PM2.5 concentrations are lower at the coarse compared to the finer resolution (˜ -8 and ˜ -6 %, respectively) but higher in summer and autumn (˜ 29 and ˜ 8 %, respectively). Simulated PM2.5 values are also mostly related to differences in convective rainfall between the two resolutions for all seasons. These differences between the two resolutions exhibit clear spatial patterns for both pollutants that vary by season, and exert a strong influence on country to country variations in estimated AF for the two resolutions. Warm season MDA8 O3 levels are higher in most of southern Europe, but lower in areas of northern and eastern Europe when simulated at the coarse resolution compared to the finer resolution. Annual-average PM2.5 concentrations are higher across most of northern and eastern Europe but lower over parts of southwest Europe at the coarse compared to the finer resolution. Across Europe, differences in the AF associated with long-term exposure to population-weighted MDA8 O3 range between -0.9 and +2.6 % (largest positive differences in southern Europe), while differences in the AF associated with long-term exposure to population-weighted annual mean PM2.5 range from -4.7 to +2.8 % (largest positive differences in eastern Europe) of the total mortality. Therefore this study, with its unique focus on Europe, demonstrates that health impact assessments calculated using modelled pollutant concentrations, are sensitive to a change in model resolution by up to ˜ ±5 % of the total mortality across Europe.

Modeling response of species to microcontaminants: comparative ecotoxicology by (sub)lethal body burdens as a function of species size and partition ratio of chemicals.

PubMed

Hendriks, A J

1995-11-01

A model was designed and calibrated with accumulation data to calculate the internal concentrations of microcontaminants in organisms as a function of a few constants and variables. The main factors are the exposure time, the external exposure concentration, the partition ratio of the compound, and the size of the taxon concerned. The model was applied to calculate the lethal and sublethal body burdens of several priority compounds and some major taxa. Estimations were generally confirmed at the order of magnitude level by measured residues and applied doses if available. According to the estimations, most priority compounds chosen were critical for most taxa above internal concentrations of 0.1 mmol.kg-1 wet wt. Trichloromethane, 1,2,4-trichlorobenzene, and hexachlorobenzene were lethal above this level only, whereas other organic microcontaminants affected at least some taxa at lower body burdens. The log(Kow) of the organic compounds ranged from 2.0 to 7.0. Keeping in mind that bioconcentration and -magnification ratios for metals may be quite variable, the lowest critical residues estimated were just below the value of 0.1 mmol.kg-1 wet wt. Here, external concentrations encountered in natural habitats seem to be a promising tool for predictive comparative ecotoxicology. The critical body burdens for plants and invertebrates may have been overestimated due to uncertainty about the parameters. Among the different taxa, however, the fish families chosen (Salmonidae and Cyprinidae) seem to be most sensitive to most compounds. Internal response concentrations of the herbicide atrazine were the lowest in micro- and macrophytes, whereas parathion affected invertebrates at low levels. The database that provided the external response concentrations was also consulted to estimate so-called extrapolation or safety factors. On average, long-term no effect concentrations in water are estimated to be about 10-30 times below short-term median lethal levels. In general, short-term versus long-term, lethal versus sublethal, and median versus no response concentration ratios each contributed factors of about 2-3 to this overall ratio. The model for internal concentrations indicated that the ratio between the short-term and the long-term LC50 will be high for large species and high octanol-water partition ratios.

Fluoride concentration level in rural area in Poldasht city and daily fluoride intake based on drinking water consumption with temperature.

PubMed

Mohammadi, Ali Akbar; Yousefi, Mahmood; Mahvi, Amir Hossein

2017-08-01

Long-term exposure to high level of fluoride can caused several adverse effects on human health including dental and skeletal fluorosis. We investigated all the drinking water source located in rural areas of Poldasht city, west Azerbaijan Province, North West Iran between 2014 and 2015. Fluoride concentration of water samples was measured by SPADNS method. We found that in the villages of Poldasht the average of fluoride concentration in drinking water sources (well, and the river) was in the range mg/l 0.28-10.23. The average daily received per 2 l of drinking water is in the range mg/l 0.7-16.6 per day per person. Drinking water demands cause fluorosis in the villages around the area residents and based on the findings of this study writers are announced suggestions below in order to take care of the health of area residents.

Long-Term Climatic and Anthropogenic Impacts on Streamwater Salinity in New York State: INCA Simulations Offer Cautious Optimism.

PubMed

Gutchess, Kristina; Jin, Li; Ledesma, José L J; Crossman, Jill; Kelleher, Christa; Lautz, Laura; Lu, Zunli

2018-02-06

The long-term application of road salts has led to a rise in surface water chloride (Cl - ) concentrations. While models have been used to assess the potential future impacts of continued deicing practices, prior approaches have not incorporated changes in climate that are projected to impact hydrogeology in the 21st century. We use an INtegrated CAtchment (INCA) model to simulate Cl - concentrations in the Tioughnioga River watershed. The model was run over a baseline period (1961-1990) and climate simulations from a range of GCMs run over three 30-year intervals (2010-2039; 2040-2069; 2070-2099). Model projections suggest that Cl - concentrations in the two river branches will continue to rise for several decades, before beginning to decline around 2040-2069, with all GCM scenarios indicating reductions in snowfall and associated salt applications over the 21st century. The delay in stream response is most likely attributed to climate change and continued contribution of Cl - from aquifers. By 2100, surface water Cl - concentrations will decrease to below 1960s values. Catchments dominated by urban lands will experience a decrease in average surface water Cl - , although moderate compared to more rural catchments.

Spatial variation of ultrafine particles and black carbon in two cities: results from a short-term measurement campaign.

PubMed

Klompmaker, Jochem O; Montagne, Denise R; Meliefste, Kees; Hoek, Gerard; Brunekreef, Bert

2015-03-01

Recently, short-term monitoring campaigns have been carried out to investigate the spatial variation of air pollutants within cities. Typically, such campaigns are based on short-term measurements at relatively large numbers of locations. It is largely unknown how well these studies capture the spatial variation of long term average concentrations. The aim of this study was to evaluate the within-site temporal and between-site spatial variation of the concentration of ultrafine particles (UFPs) and black carbon (BC) in a short-term monitoring campaign. In Amsterdam and Rotterdam (the Netherlands) measurements of number counts of particles larger than 10nm as a surrogate for UFP and BC were performed at 80 sites per city. Each site was measured in three different seasons of 2013 (winter, spring, summer). Sites were selected from busy urban streets, urban background, regional background and near highways, waterways and green areas, to obtain sufficient spatial contrast. Continuous measurements were performed for 30 min per site between 9 and 16 h to avoid traffic spikes of the rush hour. Concentrations were simultaneously measured at a reference site to correct for temporal variation. We calculated within- and between-site variance components reflecting temporal and spatial variations. Variance ratios were compared with previous campaigns with longer sampling durations per sample (24h to 14 days). The within-site variance was 2.17 and 2.44 times higher than the between-site variance for UFP and BC, respectively. In two previous studies based upon longer sampling duration much smaller variance ratios were found (0.31 and 0.09 for UFP and BC). Correction for temporal variation from a reference site was less effective for the short-term monitoring campaign compared to the campaigns with longer duration. Concentrations of BC and UFP were on average 1.6 and 1.5 times higher at urban street compared to urban background sites. No significant differences between the other site types and urban background were found. The high within to between-site concentration variances may result in the loss of precision and low explained variance when average concentrations from short-term campaigns are used to develop land use regression models. Copyright © 2014 Elsevier B.V. All rights reserved.

Risks to children from exposure to lead in air during remedial or removal activities at Superfund sites: a case study of the RSR lead smelter Superfund site.

PubMed

Khoury, Ghassan A; Diamond, Gary L

2003-01-01

Superfund sites that are contaminated with lead and undergoing remedial action generate lead-enriched dust that can be released into the air. Activities that can emit lead-enriched dust include demolition of lead smelter buildings, stacks, and baghouses; on-site traffic of heavy construction vehicles; and excavation of soil. Typically, air monitoring stations are placed around the perimeter of a site of an ongoing remediation to monitor air lead concentrations that might result from site emissions. The National Ambient Air Quality (NAAQ) standard, established in 1978 to be a quarterly average of 1.5 microg/m(3), is often used as a trigger level for corrective action to reduce emissions. This study explored modeling approaches for assessing potential risks to children from air lead emissions from the RSR Superfund site in West Dallas, TX, during demolition and removal of a smelter facility. The EPA Integrated Exposure Uptake Biokinetic (IEUBK) model and the International Commission of Radiologic Protection (ICRP) lead model were used to simulate blood lead concentrations in children, based on monitored air lead concentrations. Although air lead concentrations at monitoring stations located in the downwind community intermittently exceeded the NAAQ standard, both models indicated that exposures to children in the community areas did not pose a significant long-term or acute risk. Long-term risk was defined as greater than 5% probability of a child having a long-term blood lead concentration that exceeded 10 microg/dl, which is the CDC and the EPA blood lead concern level. Short-term or acute risk was defined as greater than 5% probability of a child having a blood lead concentration on any given day that exceeded 20 microg/dl, which is the CDC trigger level for medical evaluation (this is not intended to imply that 20 microg/dl is a threshold for health effects in children exposed acutely to airborne lead). The estimated potential long-term and short-term exposures at the downwind West Dallas community did not result in more than 5% of children exceeding the target blood lead levels. The models were also used to estimate air lead levels for short-term and long-term exposures that would not exceed specified levels of risk (risk-based concentrations, RBCs). RBCs were derived for various daily exposure durations (3 or 8 h/day) and frequencies (1-7 days/week). RBCs based on the ICRP model ranged from 0.3 (7 days/week, 8 h/day) to 4.4 microg/m(3) (1 day/week, 3 h/day) for long-term exposures and were lower than those based on the IEUBK model. For short-term exposures, the RBCs ranged from 3.5 to 29.0 microg/m(3). Recontamination of remediated residential yards from deposition of air lead emitted during remedial activities at the RSR Superfund site was also examined. The predicted increase in soil concentration due to lead deposition at the monitoring station, which represented the community at large, was 3.0 mg/kg. This potential increase in soil lead concentration was insignificant, less than 1% increase, when compared to the clean-up level of 500 mg/kg developed for residential yards at the site.

Managing risks of noncancer health effects at hazardous waste sites: A case study using the Reference Concentration (RfC) of trichloroethylene (TCE).

PubMed

Dourson, Michael L; Gadagbui, Bernard K; Thompson, Rod B; Pfau, Edward J; Lowe, John

2016-10-01

A method for determining a safety range for non-cancer risks is proposed, similar in concept to the range used for cancer in the management of waste sites. This safety range brings transparency to the chemical specific Reference Dose or Concentration by replacing their "order of magnitude" definitions with a scientifically-based range. EPA's multiple RfCs for trichloroethylene (TCE) were evaluated as a case study. For TCE, a multi-endpoint safety range was judged to be 3 μg/m(3) to 30 μg/m,(3) based on a review of kidney effects found in NTP (1988), thymus effects found in Keil et al. (2009) and cardiac effects found in the Johnson et al. (2003) study. This multi-endpoint safety range is derived from studies for which the appropriate averaging time corresponds to different exposure durations, and, therefore, can be applied to both long- and short-term exposures with appropriate consideration of exposure averaging times. For shorter-term exposures, averaging time should be based on the time of cardiac development in humans during fetal growth, an average of approximately 20-25 days. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

Analysis of synovial fluid components of hydrarthrosis in long-term hemodialysis patients.

PubMed

Shiota, E; Maekawa, M; Ohtani, M

1999-01-01

The synovial fluid components in long-term hemodialysis patients (HD; 43 knees in 43 patients) were investigated and compared with those in patients with osteoarthritis (OA; 21 knees in 21 patients) and rheumatoid arthritis (RA; 26 knees in 26 patients). The average ages in the three groups were, respectively, 60.7 years (range, 34-79 years), 63.2 years (range, 48-88 years), and 59.7 years (range, 37-76 years). The duration of hemodialysis in the HD group averaged 14.0 years (range, 4-24 years). The concentrations of hyaluronic acid, protein, and isomers of chondroitin sulfate (chondroitin 6-sulfate [C6S] and chondroitin 4-sulfate [C4S]) in the synovial fluid, and its viscosity were measured. Differences in each of the parameters were investigated according to disease clinical stage, roentgenological grade, and periods of dialysis in the HD group. The viscosity of the synovial fluid and the concentration of hyaluronic acid in HD patients were similar to those in OA patients; however, the C6S/C4S ratio in the synovial fluid of HD patients was similar to that in RA patients. The latter finding suggests that synovitis may be present in the hydrarthrosis of HD patients. The cause of this synovitis in HD patients remains to be elucidated.

The moving-window Bayesian maximum entropy framework: estimation of PM(2.5) yearly average concentration across the contiguous United States.

PubMed

Akita, Yasuyuki; Chen, Jiu-Chiuan; Serre, Marc L

2012-09-01

Geostatistical methods are widely used in estimating long-term exposures for epidemiological studies on air pollution, despite their limited capabilities to handle spatial non-stationarity over large geographic domains and the uncertainty associated with missing monitoring data. We developed a moving-window (MW) Bayesian maximum entropy (BME) method and applied this framework to estimate fine particulate matter (PM(2.5)) yearly average concentrations over the contiguous US. The MW approach accounts for the spatial non-stationarity, while the BME method rigorously processes the uncertainty associated with data missingness in the air-monitoring system. In the cross-validation analyses conducted on a set of randomly selected complete PM(2.5) data in 2003 and on simulated data with different degrees of missing data, we demonstrate that the MW approach alone leads to at least 17.8% reduction in mean square error (MSE) in estimating the yearly PM(2.5). Moreover, the MWBME method further reduces the MSE by 8.4-43.7%, with the proportion of incomplete data increased from 18.3% to 82.0%. The MWBME approach leads to significant reductions in estimation error and thus is recommended for epidemiological studies investigating the effect of long-term exposure to PM(2.5) across large geographical domains with expected spatial non-stationarity.

Longitudinal effects of air pollution on exhaled nitric oxide: the Children's Health Study.

PubMed

Berhane, Kiros; Zhang, Yue; Salam, Muhammad T; Eckel, Sandrah P; Linn, William S; Rappaport, Edward B; Bastain, Theresa M; Lurmann, Fred; Gilliland, Frank D

2014-07-01

To assess the effects of long-term variations in ambient air pollutants on longitudinal changes in exhaled nitric oxide (FeNO), a potentially useful biomarker of eosinophilic airway inflammation, based on data from the southern California Children's Health Study. Based on a cohort of 1211 schoolchildren from eight Southern California communities with FeNO measurements in 2006-2007 and 2007-2008, regression models adjusted for short-term effects of air pollution were fitted to assess the association between changes in annual long-term exposures and changes in FeNO. Increases in annual average concentrations of 24-h average NO2 and PM2.5 (scaled to the IQR of 1.8 ppb and 2.4 μg/m(3), respectively) were associated with a 2.29 ppb (CI 0.36 to 4.21; p=0.02) and a 4.94 ppb (CI 1.44 to 8.47; p=0.005) increase in FeNO, respectively, after adjustments for short-term effects of the respective pollutants. In contrast, changes in annual averages of PM10 and O3 were not significantly associated with changes in FeNO. These findings did not differ significantly by asthma status. Changes in annual average exposure to current levels of ambient air pollutants are significantly associated with changes in FeNO levels in children, independent of short-term exposures and asthma status. Use of this biomarker in population-based epidemiological research has great potential for assessing the impact of changing real world mixtures of ambient air pollutants on children's respiratory health. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Long-Term Effect of Manure and Fertilizer on Soil Organic Carbon Pools in Dryland Farming in Northwest China

PubMed Central

Liu, Enke; Yan, Changrong; Mei, Xurong; Zhang, Yanqing; Fan, Tinglu

2013-01-01

An understanding of the dynamics of soil organic carbon (SOC) as affected by farming practices is imperative for maintaining soil productivity and mitigating global warming. The objectives of this study were to investigate the effects of long-term fertilization on SOC and SOC fractions for the whole soil profile (0–100 cm) in northwest China. The study was initiated in 1979 in Gansu, China and included six treatments: unfertilized control (CK), nitrogen fertilizer (N), nitrogen and phosphorus (P) fertilizers (NP), straw plus N and P fertilizers (NP+S), farmyard manure (FYM), and farmyard manure plus N and P fertilizers (NP+FYM). Results showed that SOC concentration in the 0–20 cm soil layer increased with time except in the CK and N treatments. Long-term fertilization significantly influenced SOC concentrations and storage to 60 cm depth. Below 60 cm, SOC concentrations and storages were statistically not significant between all treatments. The concentration of SOC at different depths in 0–60 cm soil profile was higher under NP+FYM follow by under NP+S, compared to under CK. The SOC storage in 0–60 cm in NP+FYM, NP+S, FYM and NP treatments were increased by 41.3%, 32.9%, 28.1% and 17.9%, respectively, as compared to the CK treatment. Organic manure plus inorganic fertilizer application also increased labile soil organic carbon pools in 0–60 cm depth. The average concentration of particulate organic carbon (POC), dissolved organic carbon (DOC) and microbial biomass carbon (MBC) in organic manure plus inorganic fertilizer treatments (NP+S and NP+FYM) in 0–60 cm depth were increased by 64.9–91.9%, 42.5–56.9%, and 74.7–99.4%, respectively, over the CK treatment. The POC, MBC and DOC concentrations increased linearly with increasing SOC content. These results indicate that long-term additions of organic manure have the most beneficial effects in building carbon pools among the investigated types of fertilization. PMID:23437161

Long-Term Hearing Results After Ossiculoplasty.

PubMed

Cox, Matthew D; Trinidade, Aaron; Russell, James Shep; Dornhoffer, John L

2017-04-01

To determine if the OOPS index is predictive of long-term hearing results after ossiculoplasty. Case series with retrospective chart review. Tertiary care otology practice. Adult and pediatric patients (3-88 years of age). Ossiculoplasty with cartilage tympanoplasty, with or without mastoidectomy. Primary outcome measures included short-term hearing results (pure-tone average air-bone gap [PTA-ABG] measured between 60 days and 1 year after surgery), long-term hearing results (PTA-ABG measured ≥5 years after surgery), and the rate of successful ABG closure to ≤20 dB. Secondary measures included the need for revision surgery, delayed tympanic membrane graft failure, worsening conductive hearing loss (after an initially satisfactory hearing result), and recurrence of cholesteatoma. There was no significant difference between adults and children for short-term hearing results (average post-op PTA-ABG was 18.9 dB vs. 19.8 dB, respectively; p = 0.544), long-term hearing results (average final PTA-ABG was 19.3 dB vs. 19.4 dB, respectively; p = 0.922), or rate of ABG closure to less than 20 dB (63.1% vs. 58.0%, p = 0.282). Spearman's rank-order correlation (ρ) identified a strong positive correlation between OOPS index score and average post-operative PTA-ABG (ρ = 0.983; p < 0.001; 2-tailed), as well as average long-term PTA-ABG (ρ = 0.950, p < 0.001; 2-tailed). The OOPS index makes it possible to accurately prognosticate hearing outcomes in adult and pediatric patients undergoing ossiculoplasty in both the short term and the long term.

Macrobenthos and megabenthos responses to long-term, large-scale hypoxia on the Louisiana continental shelf.

PubMed

Briggs, Kevin B; Craig, J Kevin; Shivarudrappa, S; Richards, T M

2017-02-01

The macrobenthos and megabenthos responses to long-term, recurring hypoxia on the Louisiana continental shelf were compared at four locations with different historical (2000-2010) episodes of annual exposure to bottom-water hypoxia. Measurements of abundance, biomass, species diversity, and community composition of the two size classes of benthos suggested that the macrobenthic response is driven chiefly by tolerance to hypoxia, whereas the megabenthic response was affected by the ability to migrate and the availability/unavailability of macrobenthos prey at the sediment surface. The site exposed to the historically lowest average bottom-water dissolved oxygen (BWDO) concentration exhibited the lowest species diversity for macrobenthos and the highest species diversity for megabenthos, exemplifying the differential effects of hypoxia on different size classes. The high diversity and smaller average size of the megabenthos at the lowest DO site was due to high abundance of invertebrates and a preponderance of small, less vagile fishes that appeared to remain in the area after larger dominant sciaenids had presumably emigrated. The average size and the depth of habitation in the sediment of macrobenthos prey may have also influenced the abundance and biomass of megabenthos foragers. Published by Elsevier Ltd.

Long-term increases in young-of-the-year growth of Arctic cisco Coregonus autumnalis and environmental influences

USGS Publications Warehouse

Von Biela, V.R.; Zimmerman, C.E.; Moulton, L.L.

2011-01-01

Arctic cisco Coregonus autumnalis young-of-year (YOY) growth was used as a proxy to examine the long-term response of a high-latitude fish population to changing climate from 1978 to 2004. YOY growth increased over time (r2 = 0??29) and was correlated with monthly averages of the Arctic oscillation index, air temperature, east wind speed, sea-ice concentration and river discharge with and without time lags. Overall, the most prevalent correlates to YOY growth were sea-ice concentration lagged 1 year (significant correlations in 7 months; r2 = 0??14-0??31) and Mackenzie River discharge lagged 2 years (significant correlations in 8 months; r2 = 0??13-0??50). The results suggest that decreased sea-ice concentrations and increased river discharge fuel primary production and that life cycles of prey species linking increased primary production to fish growth are responsible for the time lag. Oceanographic studies also suggest that sea ice concentration and fluvial inputs from the Mackenzie River are key factors influencing productivity in the Beaufort Sea. Future research should assess the possible mechanism relating sea ice concentration and river discharge to productivity at upper trophic levels. Journal of Fish Biology ?? 2010 The Fisheries Society of the British Isles. No claim to original US government works.

42 CFR 412.503 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-10-01

... from a long-term care hospital based on clinical characteristics and average resource use, for... hospital based on clinical characteristics and average resource use, for prospective payment purposes for... PROSPECTIVE PAYMENT SYSTEMS FOR INPATIENT HOSPITAL SERVICES Prospective Payment System for Long-Term Care...

42 CFR 412.503 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-10-01

... from a long-term care hospital based on clinical characteristics and average resource use, for... hospital based on clinical characteristics and average resource use, for prospective payment purposes for... PROSPECTIVE PAYMENT SYSTEMS FOR INPATIENT HOSPITAL SERVICES Prospective Payment System for Long-Term Care...

42 CFR 412.503 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-10-01

... from a long-term care hospital based on clinical characteristics and average resource use, for... hospital based on clinical characteristics and average resource use, for prospective payment purposes for... PROSPECTIVE PAYMENT SYSTEMS FOR INPATIENT HOSPITAL SERVICES Prospective Payment System for Long-Term Care...

42 CFR 412.503 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-10-01

... from a long-term care hospital based on clinical characteristics and average resource use, for... hospital based on clinical characteristics and average resource use, for prospective payment purposes for... PROSPECTIVE PAYMENT SYSTEMS FOR INPATIENT HOSPITAL SERVICES Prospective Payment System for Long-Term Care...

Long-term climate change and the geochemical cycle of carbon

NASA Technical Reports Server (NTRS)

Marshall, Hal G.; Walker, James C. G.; Kuhn, William R.

1988-01-01

The response of the coupled climate-geochemical system to changes in paleography is examined in terms of the biogeochemical carbon cycle. The simple, zonally averaged energy balance climate model combined with a geochemical carbon cycle model, which was developed to study climate changes, is described. The effects of latitudinal distributions of the continents on the carbon cycle are investigated, and the global silicate weathering rate as a function of latitude is measured. It is observed that a concentration of land area at high altitudes results in a high CO2 partial pressure and a high global average temperature, and for land at low latitudes a cold globe and ice are detected. It is noted that the CO2 greenhouse feedback effect is potentially strong and has a stabilizing effect on the climate system.

Investigation of Ground-Level Ozone and High-Pollution Episodes in a Megacity of Eastern China

PubMed Central

Zhao, Heng; Wang, Shanshan; Wang, Wenxin; Liu, Rui; Zhou, Bin

2015-01-01

Differential Optical Absorption Spectroscopy (DOAS) was used for the long-term observation of ground-level ozone (O3) from March 2010 to March 2013 over Shanghai, China. The 1-hour average concentration of O3 was 27.2 ± 17.0 ppbv. O3 level increased during spring, reached the peak in late spring and early summer, and then decreased in autumn and finally dropped to the bottom in winter. The highest monthly average O3 concentration in June (41.1 ppbv) was nearly three times as high as the lowest level recorded in December (15.2 ppbv). In terms of pollution episodes, 56 hourly samples (on 14 separate days) in 2010 exceeded the 1-hour ozone limit of 200 μg/m3 specified by the Grade II of the Chinese Ambient Air Quality Standards (CAAQS, revised GB 3095-2012). Utilizing the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model, the primary contribution to high ozone days (HODs) was identified as the regional transportation of volatile organic compounds (VOC) and high concentrations of O3 from the chemical industrial zone in the Jinshan district of Shanghai. HODs showed higher concentrations of HONO and NO2 than non-episode conditions, implying that HONO at high concentration during HODs was capable of increasing the O3 concentration. The photolysis rate of HONO was estimated, suggesting that the larger number of OH radicals resulting from high concentrations of HONO have a considerable impact on ozone concentrations. PMID:26121146

Evaluation of an 18-year CMAQ simulation: Seasonal variations and long-term temporal changes in sulfate and nitrate

NASA Astrophysics Data System (ADS)

Civerolo, Kevin; Hogrefe, Christian; Zalewsky, Eric; Hao, Winston; Sistla, Gopal; Lynn, Barry; Rosenzweig, Cynthia; Kinney, Patrick L.

2010-10-01

This paper compares spatial and seasonal variations and temporal trends in modeled and measured concentrations of sulfur and nitrogen compounds in wet and dry deposition over an 18-year period (1988-2005) over a portion of the northeastern United States. Substantial emissions reduction programs occurred over this time period, including Title IV of the Clean Air Act Amendments of 1990 which primarily resulted in large decreases in sulfur dioxide (SO 2) emissions by 1995, and nitrogen oxide (NO x) trading programs which resulted in large decreases in warm season NO x emissions by 2004. Additionally, NO x emissions from mobile sources declined more gradually over this period. The results presented here illustrate the use of both operational and dynamic model evaluation and suggest that the modeling system largely captures the seasonal and long-term changes in sulfur compounds. The modeling system generally captures the long-term trends in nitrogen compounds, but does not reproduce the average seasonal variation or spatial patterns in nitrate.

Associations between long-term exposure to chemical constituents of fine particulate matter (PM2.5) and mortality in Medicare enrollees in the eastern United States.

PubMed

Chung, Yeonseung; Dominici, Francesca; Wang, Yun; Coull, Brent A; Bell, Michelle L

2015-05-01

Several epidemiological studies have reported that long-term exposure to fine particulate matter (PM2.5) is associated with higher mortality. Evidence regarding contributions of PM2.5 constituents is inconclusive. We assembled a data set of 12.5 million Medicare enrollees (≥ 65 years of age) to determine which PM2.5 constituents are a) associated with mortality controlling for previous-year PM2.5 total mass (main effect); and b) elevated in locations exhibiting stronger associations between previous-year PM2.5 and mortality (effect modification). For 518 PM2.5 monitoring locations (eastern United States, 2000-2006), we calculated monthly mortality rates, monthly long-term (previous 1-year average) PM2.5, and 7-year averages (2000-2006) of major PM2.5 constituents [elemental carbon (EC), organic carbon matter (OCM), sulfate (SO42-), silicon (Si), nitrate (NO3-), and sodium (Na)] and community-level variables. We applied a Bayesian hierarchical model to estimate location-specific mortality rates associated with previous-year PM2.5 (model level 1) and identify constituents that contributed to the spatial variability of mortality, and constituents that modified associations between previous-year PM2.5 and mortality (model level 2), controlling for community-level confounders. One-standard deviation (SD) increases in 7-year average EC, Si, and NO3- concentrations were associated with 1.3% [95% posterior interval (PI): 0.3, 2.2], 1.4% (95% PI: 0.6, 2.4), and 1.2% (95% PI: 0.4, 2.1) increases in monthly mortality, controlling for previous-year PM2.5. Associations between previous-year PM2.5 and mortality were stronger in combination with 1-SD increases in SO42- and Na. Long-term exposures to PM2.5 and several constituents were associated with mortality in the elderly population of the eastern United States. Moreover, some constituents increased the association between long-term exposure to PM2.5 and mortality. These results provide new evidence that chemical composition can partly explain the differential toxicity of PM2.5.

Ambient air pollution, lung function, and airway responsiveness in asthmatic children.

PubMed

Ierodiakonou, Despo; Zanobetti, Antonella; Coull, Brent A; Melly, Steve; Postma, Dirkje S; Boezen, H Marike; Vonk, Judith M; Williams, Paul V; Shapiro, Gail G; McKone, Edward F; Hallstrand, Teal S; Koenig, Jane Q; Schildcrout, Jonathan S; Lumley, Thomas; Fuhlbrigge, Anne N; Koutrakis, Petros; Schwartz, Joel; Weiss, Scott T; Gold, Diane R

2016-02-01

Although ambient air pollution has been linked to reduced lung function in healthy children, longitudinal analyses of pollution effects in asthmatic patients are lacking. We sought to investigate pollution effects in a longitudinal asthma study and effect modification by controller medications. We examined associations of lung function and methacholine responsiveness (PC20) with ozone, carbon monoxide (CO), nitrogen dioxide, and sulfur dioxide concentrations in 1003 asthmatic children participating in a 4-year clinical trial. We further investigated whether budesonide and nedocromil modified pollution effects. Daily pollutant concentrations were linked to ZIP/postal code of residence. Linear mixed models tested associations of within-subject pollutant concentrations with FEV1 and forced vital capacity (FVC) percent predicted, FEV1/FVC ratio, and PC20, adjusting for seasonality and confounders. Same-day and 1-week average CO concentrations were negatively associated with postbronchodilator percent predicted FEV1 (change per interquartile range, -0.33 [95% CI, -0.49 to -0.16] and -0.41 [95% CI, -0.62 to -0.21], respectively) and FVC (-0.19 [95% CI, -0.25 to -0.07] and -0.25 [95% CI, -0.43 to -0.07], respectively). Longer-term 4-month CO averages were negatively associated with prebronchodilator percent predicted FEV1 and FVC (-0.36 [95% CI, -0.62 to -0.10] and -0.21 [95% CI, -0.42 to -0.01], respectively). Four-month averaged CO and ozone concentrations were negatively associated with FEV1/FVC ratio (P < .05). Increased 4-month average nitrogen dioxide concentrations were associated with reduced postbronchodilator FEV1 and FVC percent predicted. Long-term exposures to sulfur dioxide were associated with reduced PC20 (percent change per interquartile range, -6% [95% CI, -11% to -1.5%]). Treatment augmented the negative short-term CO effect on PC20. Air pollution adversely influences lung function and PC20 in asthmatic children. Treatment with controller medications might not protect but rather worsens the effects of CO on PC20. This clinical trial design evaluates modification of pollution effects by treatment without confounding by indication. Copyright © 2015 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

Associations of long-term shift work with waking salivary cortisol concentration and patterns among police officers.

PubMed

Fekedulegn, Desta; Burchfiel, Cecil M; Violanti, John M; Hartley, Tara A; Charles, Luenda E; Andrew, Michael E; Miller, Diane B

2012-01-01

The objective of this study was to evaluate whether long-term shift work is associated with both the total hormonal secretion after awakening and the pattern of the cortisol levels during the first hour following awakening, among 65 randomly selected police officers who represent a high stress occupation. Dominant shift (Day, Afternoon, or Midnight) was ascertained using daily payroll records of each participant's work activities during the 6-8 yrs prior to saliva sampling. Four salivary samples were collected at 15 min intervals upon first awakening. After accounting for potential confounders, salivary cortisol concentrations averaged across all four time points and total area under the curve differed significantly across shift with midnight shift workers showing suppressed awakening cortisol response relative to the afternoon and day shift. The percent of hours worked on midnight shift was inversely correlated with total awakening cortisol output. In contrast, the pattern of cortisol secretion during the first hour following waking appeared not to be affected as no significant interaction effect was found between time since awakening and shift work. The results show that long-term midnight shift work is associated with decreased absolute mean level and total volume of cortisol released over the waking period.

Associations of Long-term Shift Work with Waking Salivary Cortisol Concentration and Patterns among Police Officers

PubMed Central

FEKEDULEGN, Desta; BURCHFIEL, Cecil M.; VIOLANTI, John M.; HARTLEY, Tara A.; CHARLES, Luenda E.; ANDREW, Michael E.; MILLER, Diane B.

2015-01-01

The objective of this study was to evaluate whether long-term shift work is associated with both the total hormonal secretion after awakening and the pattern of the cortisol levels during the first hour following awakening, among 65 randomly selected police officers who represent a high stress occupation. Dominant shift (Day, Afternoon, or Midnight) was ascertained using daily payroll records of each participant’s work activities during the 6–8 yrs prior to saliva sampling. Four salivary samples were collected at 15 min intervals upon first awakening. After accounting for potential confounders, salivary cortisol concentrations averaged across all four time points and total area under the curve differed significantly across shift with midnight shift workers showing suppressed awakening cortisol response relative to the afternoon and day shift. The percent of hours worked on midnight shift was inversely correlated with total awakening cortisol output. In contrast, the pattern of cortisol secretion during the first hour following waking appeared not to be affected as no significant interaction effect was found between time since awakening and shift work. The results show that long-term midnight shift work is associated with decreased absolute mean level and total volume of cortisol released over the waking period. PMID:23047078

Spatial and temporal variations of metal content and water quality in the Belaya River Basin

NASA Astrophysics Data System (ADS)

Fashchevskaia, T. B.; Motovilov, Y.

2016-12-01

The aim of this research is to identify the spatiotemporal regularities of iron, copper and zinc contents dynamics in the streams of the Belaya River basin. The Belaya River is situated in the South Ural region and is one of the biggest tributary in the Volga River basin with catchment area of 142 000 km2. More than sixty years the diverse economic activities are carried out in the Belaya River basin, the intensity of this activity is characterized by high temporal variability. The leading industries in the region are oil, mining, petroleum processing, chemistry and petro chemistry, mechanical engineering, metallurgy, power industry. The dynamics of human activities in the catchment and intra and inter-annual changes in the water quality are analyzed for the period 1969-2007 years. Inter-annual dynamics of the metal content in the river waters was identified on the basis of the long-term hydrological monitoring statistics at the 32 sites. It was found that the dynamics of intensity of economic activities in the Belaya River basin is the cause statistically significant changes in the metal content of the river network. Statistically homogeneous time intervals have been set for each monitoring site. Within these time intervals there were obtained averaged reliable quantitative estimations of water quality. Empirical probability distributions of iron, copper and zinc concentrations for various phases of the water regime in all investigated monitoring sites were approximated by Pearson type III curves and the averages of the concentration values, the coefficient of variation and asymmetry, as well as the values of the concentrations of metal in the range of 1-95% of frequency were estimated. It was found that by the end of the test period, the average long-term concentrations for iron and copper exceed MAC for fishery use, for zinc become smaller MAC in many streams of Belaya River basin. Acknowledgements. The work was financially supported by the Russian Foundation for Basic Research (Grant 15-05-09022)

Associations between short-term exposure to nitrogen dioxide and mortality in 17 Chinese cities: the China Air Pollution and Health Effects Study (CAPES).

PubMed

Chen, Renjie; Samoli, Evangelia; Wong, Chit-Ming; Huang, Wei; Wang, Zongshuang; Chen, Bingheng; Kan, Haidong

2012-09-15

Few multi-city studies in Asian developing countries have examined the acute health effects of ambient nitrogen dioxide (NO(2)). In the China Air Pollution and Health Effects Study (CAPES), we investigated the short-term association between NO(2) and mortality in 17 Chinese cities. We applied two-stage Bayesian hierarchical models to obtain city-specific and national average estimates for NO(2). In each city, we used Poisson regression models incorporating natural spline smoothing functions to adjust for long-term and seasonal trend of mortality, as well as other time-varying covariates. We examined the associations by age, gender and education status. We combined the individual-city estimates of the concentration-response curves to get an overall NO(2)-mortality association in China. The averaged daily concentrations of NO(2) in the 17 Chinese cities ranged from 26 μg/m(3) to 67 μg/m(3). In the combined analysis, a 10-μg/m(3) increase in two-day moving averaged NO(2) was associated with a 1.63% [95% posterior interval (PI), 1.09 to 2.17], 1.80% (95% PI, 1.00 to 2.59) and 2.52% (95% PI, 1.44 to 3.59) increase of total, cardiovascular, and respiratory mortality, respectively. These associations remained significant after adjustment for ambient particles or sulfur dioxide (SO(2)). Older people appeared to be more vulnerable to NO(2) exposure. The combined concentration-response curves indicated a linear association. Conclusively, this largest epidemiologic study of NO(2) in Asian developing countries to date suggests that short-term exposure to NO(2) is associated with increased mortality risk. Copyright © 2012 Elsevier Ltd. All rights reserved.

Disinfection Byproducts in Drinking Water and Evaluation of Potential Health Risks of Long-Term Exposure in Nigeria

PubMed Central

Akintokun, Oyeronke A.; Adedapo, Adebusayo E.

2017-01-01

Levels of trihalomethanes (THMs) in drinking water from water treatment plants (WTPs) in Nigeria were studied using a gas chromatograph (GC Agilent 7890A with autosampler Agilent 7683B) equipped with electron capture detector (ECD). The mean concentrations of the trihalomethanes ranged from zero in raw water samples to 950 μg/L in treated water samples. Average concentration values of THMs in primary and secondary disinfection samples exceeded the standard maximum contaminant levels. Results for the average THMs concentrations followed the order TCM > BDCM > DBCM > TBM. EPA-developed models were adopted for the estimation of chronic daily intakes (CDI) and excess cancer incidence through ingestion pathway. Higher average intake was observed in adults (4.52 × 10−2 mg/kg-day), while the ingestion in children (3.99 × 10−2 mg/kg-day) showed comparable values. The total lifetime cancer incidence rate was relatively higher in adults than children with median values 244 and 199 times the negligible risk level. PMID:28900447

The Gaussian atmospheric transport model and its sensitivity to the joint frequency distribution and parametric variability.

PubMed

Hamby, D M

2002-01-01

Reconstructed meteorological data are often used in some form of long-term wind trajectory models for estimating the historical impacts of atmospheric emissions. Meteorological data for the straight-line Gaussian plume model are put into a joint frequency distribution, a three-dimensional array describing atmospheric wind direction, speed, and stability. Methods using the Gaussian model and joint frequency distribution inputs provide reasonable estimates of downwind concentration and have been shown to be accurate to within a factor of four. We have used multiple joint frequency distributions and probabilistic techniques to assess the Gaussian plume model and determine concentration-estimate uncertainty and model sensitivity. We examine the straight-line Gaussian model while calculating both sector-averaged and annual-averaged relative concentrations at various downwind distances. The sector-average concentration model was found to be most sensitive to wind speed, followed by horizontal dispersion (sigmaZ), the importance of which increases as stability increases. The Gaussian model is not sensitive to stack height uncertainty. Precision of the frequency data appears to be most important to meteorological inputs when calculations are made for near-field receptors, increasing as stack height increases.

Isotopic Techniques for Assessment of Groundwater Discharge to the Coastal Ocean

DTIC Science & Technology

2003-09-30

estimates of the pore water Rn activity. The red line (based on an average groundwater concentration of 170 dpm/L) is considered our best estimate and...Isotopic Techniques For Assessment of Groundwater Discharge to the Coastal Ocean William C. Burnett Department of Oceanography Florida State...evaluating the influence of submarine groundwater discharge (SGD) into the ocean. Our long-term goal is to develop geochemical tools (e.g., radon and

222Rn variations in Mystery Cave, Minnesota

USGS Publications Warehouse

Lively, R.S.; Krafthefer, B.C.

1995-01-01

222Rn concentrations and meteorological parameters were measured at 4- h intervals over a 2-y period in Mystery Cave, southeastern Minnesota. Continuous radon monitors and meteorological sensors connected to data loggers were installed at several locations along commercial tour routes. 222Rn concentrations ranged as high as 25 kBq m-3 in summer and 20 kBq m-3 in winter. Average winter concentrations were lower than summer by at least a factor of two. Seasonal radon variations were correlative with outside air temperatures. During the winter, radon concentrations were observed to fluctuate periodically by factors of 20 or more in under 24 h. Both the long- and short-term variations are correlative with temperature- induced mixing of cave air with surface air.

Chemical climatology of the southeastern United States, 1999-2013

NASA Astrophysics Data System (ADS)

Hidy, G. M.; Blanchard, C. L.; Baumann, K.; Edgerton, E.; Tanenbaum, S.; Shaw, S.; Knipping, E.; Tombach, I.; Jansen, J.; Walters, J.

2014-11-01

A series of experiments (the Southern Oxidant and Aerosol Study - SOAS) took place in central Alabama in June-July, 2013 as part of the broader Southern Atmosphere Study (SAS). These projects were aimed at studying oxidant photochemistry and formation and impacts of aerosols at a detailed process level in a location where high biogenic organic vapor emissions interact with anthropogenic emissions, and the atmospheric chemistry occurs in a subtropical climate in North America. The majority of the ground-based experiments were located at the Southeastern Aerosol Research and Characterization (SEARCH) Centreville (CTR) site near Brent, Alabama, where extensive, unique aerometric measurements of trace gases and particles and meteorology were made beginning in the early 1990s through 2013. The SEARCH network data permits a characterization of the temporal and spatial context of the SOAS findings. Our earlier analyses of emissions and air quality trends are extended through 2013 to provide a perspective for continued decline in ambient concentrations, and the implications of these changes to regional sulfur oxide, nitrogen-ozone, and carbon chemistry. The narrative supports the SAS program in terms of long-term average chemistry (chemical climatology) and short-term comparisons of early summer average spatial variability across the southeastern US at high temporal (hourly) resolution. The long-term measurements show that the SOAS experiments took place during the second wettest and coolest year in the 2000-2013 period, with lower than average solar radiation. The pollution levels at CTR and other SEARCH sites were the lowest since full measurements began in 1999. Changes in anthropogenic gas and particle emissions between 1999 and 2013 account for the decline in pollutant concentrations at the monitoring sites in the region. The data provide an opportunity to contrast SOAS results with temporally and spatially variable conditions in support of the development of tests for the robustness of SOAS findings.

The singer's formant and speaker's ring resonance: a long-term average spectrum analysis.

PubMed

Lee, Sang-Hyuk; Kwon, Hee-Jun; Choi, Hyun-Jin; Lee, Nam-Hun; Lee, Sung-Jin; Jin, Sung-Min

2008-06-01

We previously showed that a trained tenor's voice has the conventional singer's formant at the region of 3 kHz and another energy peak at 8-9 kHz. Singers in other operatic voice ranges are assumed to have the same peak in their singing and speaking voice. However, to date, no specific measurement of this has been made. Tenors, baritones, sopranos and mezzo sopranos were chosen to participate in this study of the singer's formant and the speaker's ring resonance. Untrained males (n=15) and females (n=15) were included in the control group. Each subject was asked to produce successive /a/ vowel sounds in their singing and speaking voice. For singing, the low pitch was produced in the chest register and the high notes in the head register. We collected the data on the long-term average spectra of the speaking and singing voices of the trained singers and the control groups. For the sounds produced from the head register, a significant energy concentration was seen in both 2.2-3.4 kHz and 7.5-8.4 kHz regions (except for the voices of the mezzo sopranos) in the trained singer group when compared to the control groups. Also, the chest register had a significant energy concentration in the 4 trained singer groups at the 2.2-3.1 kHz and 7.8-8.4 kHz. For speaking sound, all trained singers had a significant energy concentration at 2.2-5.3 kHz and sopranos had another energy concentration at 9-10 kHz. The results of this study suggest that opera singers have more energy concentration in the singer's formant/speaker's ring region, in both singing and speaking voices. Furthermore, another region of energy concentration was identified in opera singer's singing sound and in sopranos' speaking sound at 8-9 kHz. The authors believe that these energy concentrations may contribute to the rich voice of trained singers.

Spatial and temporal variations of water quality in the Belaya River Basin

NASA Astrophysics Data System (ADS)

Fashchevskaia, Tatiana; Motovilov, Yuri

2016-04-01

The aim of this research is to identify the spatiotemporal regularities of the maintenance of nitrogen compounds in the streams of the Belaya River basin. The dynamics of human activities in the catchment and intra and inter-annual changes in the water quality are analyzed for the period 1969-2007 years. The Belaya River is situated in the South Ural region and is one of the biggest tributary in the Volga River basin with catchment area of 142 000 km2. The Belaya River provides drinking water for a lot of settlements, it is used for industrial and agricultural water supply, fishery use, it is also a wastewater receiver for industry and housing and communal services. More than sixty years the diverse economic activities are carried out in the Belaya River basin, the intensity of this activity is characterized by high temporal variability. The leading industries in the region are oil mining, petroleum processing, chemistry and petro chemistry, mechanical engineering, metallurgy, power industry, timber industry. About 50% of the river basin is used for agriculture. Inter-annual dynamics of the nitrogen content in the river waters was identified on the basis of the long-term hydrological monitoring statistics at the 32 sites. It was found that the dynamics of the intensity of economic activities in the Belaya River basin is the cause statistically significant changes in the content of nitrogen compounds of the river network. Statistically homogeneous time intervals have been set for each monitoring site. Within these time intervals there were obtained averaged reliable quantitative estimations of water quality. Calculations showed that from the end of 1980 to 2007 the average long-term content of nutrients in the river waters is reduced in comparison with the previous period: ammonium nitrogen - in 1,6-7,5 times, nitrite nitrogen - 1,9-37,3 times, but the average concentration of nitrate nitrogen is increased in 1,4-6,6 times. Empirical probability distributions of ammonia nitrogen, nitrite nitrogen and nitrate nitrogen concentrations for various phases of the water regime in all investigated monitoring sites were approximated by Pearson type III curve and the averages of the concentration values for the water regime phases, the coefficient of variation and asymmetry, as well as the values of the concentrations of nitrogen compounds in the range of 1-95% of frequency ware estimated. It was found that by the end of the test period, the average long-term values for nitrogen compounds become smaller MAC in many streams of Belaya River basin that points to the suitability of river water quality for fishery use. However, in some points of river network there may be excess of MAC. Acknowledgements. The work was financially supported by the Russian Foundation for Basic Research (Grant 15-05-09022)

New reporting procedures based on long-term method detection levels and some considerations for interpretations of water-quality data provided by the U.S. Geological Survey National Water Quality Laboratory

USGS Publications Warehouse

Childress, Carolyn J. Oblinger; Foreman, William T.; Connor, Brooke F.; Maloney, Thomas J.

1999-01-01

This report describes the U.S. Geological Survey National Water Quality Laboratory?s approach for determining long-term method detection levels and establishing reporting levels, details relevant new reporting conventions, and provides preliminary guidance on interpreting data reported with the new conventions. At the long-term method detection level concentration, the risk of a false positive detection (analyte reported present at the long-term method detection level when not in sample) is no more than 1 percent. However, at the long-term method detection level, the risk of a false negative occurrence (analyte reported not present when present at the long-term method detection level concentration) is up to 50 percent. Because this false negative rate is too high for use as a default 'less than' reporting level, a more reliable laboratory reporting level is set at twice the determined long-term method detection level. For all methods, concentrations measured between the laboratory reporting level and the long-term method detection level will be reported as estimated concentrations. Non-detections will be censored to the laboratory reporting level. Adoption of the new reporting conventions requires a full understanding of how low-concentration data can be used and interpreted and places responsibility for using and presenting final data with the user rather than with the laboratory. Users must consider that (1) new laboratory reporting levels may differ from previously established minimum reporting levels, (2) long-term method detection levels and laboratory reporting levels may change over time, and (3) estimated concentrations are less certain than concentrations reported above the laboratory reporting level. The availability of uncensored but qualified low-concentration data for interpretation and statistical analysis is a substantial benefit to the user. A decision to censor data after they are reported from the laboratory may still be made by the user, if merited, on the basis of the intended use of the data.

Long-term effect of linseed plus nitrate fed to dairy cows on enteric methane emission and nitrate and nitrite residuals in milk.

PubMed

Guyader, J; Doreau, M; Morgavi, D P; Gérard, C; Loncke, C; Martin, C

2016-07-01

A previous study showed the additive methane (CH4)-mitigating effect of nitrate and linseed fed to non-lactating cows. Before practical application, the use of this new strategy in dairy cows requires further investigation in terms of persistency of methanogenesis reduction and absence of residuals in milk products. The objective of this experiment was to study the long-term effect of linseed plus nitrate on enteric CH4 emission and performance in dairy cows. We also assessed the effect of this feeding strategy on the presence of nitrate residuals in milk products, total tract digestibility, nitrogen (N) balance and rumen fermentation. A total of 16 lactating Holstein cows were allocated to two groups in a randomised design conducted in parallel for 17 weeks. Diets were on a dry matter (DM) basis: (1) control (54% maize silage, 6% hay and 40% concentrate; CON) or (2) control plus 3.5% added fat from linseed and 1.8% nitrate (LIN+NIT). Diets were equivalent in terms of CP (16%), starch (28%) and NDF (33%), and were offered twice daily. Cows were fed ad libitum, except during weeks 5, 16 and 17 in which feed was restricted to 95% of dry matter intake (DMI) to ensure complete consumption of meals during measurement periods. Milk production and DMI were measured weekly. Nitrate and nitrite concentrations in milk and milk products were determined monthly. Daily CH4 emission was quantified in open circuit respiration chambers (weeks 5 and 16). Total tract apparent digestibility, N balance and rumen fermentation parameters were determined in week 17. Daily DMI tended to be lower with LIN+NIT from week 4 to 16 (-5.1 kg/day on average). The LIN+NIT diet decreased milk production during 6 non-consecutive weeks (-2.5 kg/day on average). Nitrate or nitrite residuals were not detected in milk and associated products. The LIN+NIT diet reduced CH4 emission to a similar extent at the beginning and end of the trial (-47%, g/day; -30%, g/kg DMI; -33%, g/kg fat- and protein-corrected milk, on average). Diets did not affect N efficiency and nutrients digestibility. In the rumen, LIN+NIT did not affect protozoa number but reduced total volatile fatty acid (-12%) and propionate (-31%) concentrations. We concluded that linseed plus nitrate may have a long-term CH4-mitigating effect in dairy cows and that consuming milk products from cows fed nitrate may be safe in terms of nitrate and nitrite residuals. Further work is required to optimise the doses of linseed plus nitrate to avoid reduced cows performance.

Long-term cloud condensation nuclei number concentration, particle number size distribution and chemical composition measurements at regionally representative observatories

NASA Astrophysics Data System (ADS)

Schmale, Julia; Henning, Silvia; Decesari, Stefano; Henzing, Bas; Keskinen, Helmi; Sellegri, Karine; Ovadnevaite, Jurgita; Pöhlker, Mira L.; Brito, Joel; Bougiatioti, Aikaterini; Kristensson, Adam; Kalivitis, Nikos; Stavroulas, Iasonas; Carbone, Samara; Jefferson, Anne; Park, Minsu; Schlag, Patrick; Iwamoto, Yoko; Aalto, Pasi; Äijälä, Mikko; Bukowiecki, Nicolas; Ehn, Mikael; Frank, Göran; Fröhlich, Roman; Frumau, Arnoud; Herrmann, Erik; Herrmann, Hartmut; Holzinger, Rupert; Kos, Gerard; Kulmala, Markku; Mihalopoulos, Nikolaos; Nenes, Athanasios; O'Dowd, Colin; Petäjä, Tuukka; Picard, David; Pöhlker, Christopher; Pöschl, Ulrich; Poulain, Laurent; Prévôt, André Stephan Henry; Swietlicki, Erik; Andreae, Meinrat O.; Artaxo, Paulo; Wiedensohler, Alfred; Ogren, John; Matsuki, Atsushi; Yum, Seong Soo; Stratmann, Frank; Baltensperger, Urs; Gysel, Martin

2018-02-01

Aerosol-cloud interactions (ACI) constitute the single largest uncertainty in anthropogenic radiative forcing. To reduce the uncertainties and gain more confidence in the simulation of ACI, models need to be evaluated against observations, in particular against measurements of cloud condensation nuclei (CCN). Here we present a data set - ready to be used for model validation - of long-term observations of CCN number concentrations, particle number size distributions and chemical composition from 12 sites on 3 continents. Studied environments include coastal background, rural background, alpine sites, remote forests and an urban surrounding. Expectedly, CCN characteristics are highly variable across site categories. However, they also vary within them, most strongly in the coastal background group, where CCN number concentrations can vary by up to a factor of 30 within one season. In terms of particle activation behaviour, most continental stations exhibit very similar activation ratios (relative to particles > 20 nm) across the range of 0.1 to 1.0 % supersaturation. At the coastal sites the transition from particles being CCN inactive to becoming CCN active occurs over a wider range of the supersaturation spectrum. Several stations show strong seasonal cycles of CCN number concentrations and particle number size distributions, e.g. at Barrow (Arctic haze in spring), at the alpine stations (stronger influence of polluted boundary layer air masses in summer), the rain forest (wet and dry season) or Finokalia (wildfire influence in autumn). The rural background and urban sites exhibit relatively little variability throughout the year, while short-term variability can be high especially at the urban site. The average hygroscopicity parameter, κ, calculated from the chemical composition of submicron particles was highest at the coastal site of Mace Head (0.6) and lowest at the rain forest station ATTO (0.2-0.3). We performed closure studies based on κ-Köhler theory to predict CCN number concentrations. The ratio of predicted to measured CCN concentrations is between 0.87 and 1.4 for five different types of κ. The temporal variability is also well captured, with Pearson correlation coefficients exceeding 0.87. Information on CCN number concentrations at many locations is important to better characterise ACI and their radiative forcing. But long-term comprehensive aerosol particle characterisations are labour intensive and costly. Hence, we recommend operating migrating-CCNCs to conduct collocated CCN number concentration and particle number size distribution measurements at individual locations throughout one year at least to derive a seasonally resolved hygroscopicity parameter. This way, CCN number concentrations can only be calculated based on continued particle number size distribution information and greater spatial coverage of long-term measurements can be achieved.

The role of long-range transport and domestic emissions in determining atmospheric secondary inorganic particle concentrations across the UK

NASA Astrophysics Data System (ADS)

Vieno, M.; Heal, M. R.; Hallsworth, S.; Famulari, D.; Doherty, R. M.; Dore, A. J.; Tang, Y. S.; Braban, C. F.; Leaver, D.; Sutton, M. A.; Reis, S.

2014-08-01

Surface concentrations of secondary inorganic particle components over the UK have been analysed for 2001-2010 using the EMEP4UK regional atmospheric chemistry transport model and evaluated against measurements. Gas/particle partitioning in the EMEP4UK model simulations used a bulk approach, which may lead to uncertainties in simulated secondary inorganic aerosol. However, model simulations were able to accurately represent both the long-term decadal surface concentrations of particle sulfate and nitrate and an episode in early 2003 of substantially elevated nitrate measured across the UK by the AGANet network. The latter was identified as consisting of three separate episodes, each of less than 1 month duration, in February, March and April. The primary cause of the elevated nitrate levels across the UK was meteorological: a persistent high-pressure system, whose varying location impacted the relative importance of transboundary versus domestic emissions. Whilst long-range transport dominated the elevated nitrate in February, in contrast it was domestic emissions that mainly contributed to the March episode, and for the April episode both domestic emissions and long-range transport contributed. A prolonged episode such as the one in early 2003 can have substantial impact on annual average concentrations. The episode led to annual concentration differences at the regional scale of similar magnitude to those driven by long-term changes in precursor emissions over the full decade investigated here. The results demonstrate that a substantial part of the UK, particularly the south and southeast, may be close to or exceeding annual mean limit values because of import of inorganic aerosol components from continental Europe under specific conditions. The results reinforce the importance of employing multiple year simulations in the assessment of emissions reduction scenarios on particulate matter concentrations and the need for international agreements to address the transboundary component of air pollution.

Chemotaxonomy in some Mediterranean plants and implications for fossil biomarker records

NASA Astrophysics Data System (ADS)

Norström, Elin; Katrantsiotis, Christos; Smittenberg, Rienk H.; Kouli, Katerina

2017-12-01

The increasing utilization of n-alkanes as plant-derived paleo-environmental proxies calls for improved chemotaxonomic control of the modern flora in order to calibrate fossil sediment records to modern analogues. Several recent studies have investigated long-chain n-alkane concentrations and chain-length distributions in species from various vegetation biomes, but up to date, the Mediterranean flora is relatively unexplored in this respect. Here, we analyse the n-alkane concentrations and chain-length distributions in some of the most common species of the modern macchia and phrygana vegetation in south western Peloponnese, Greece. We show that the drought adapted phrygana herbs and shrubs, as well as some of the sclerophyll and gymnosperm macchia components, produce high concentrations of n-alkanes, on average more than double n-alkane production in local wetland reed vegetation. Furthermore, the chain-length distribution in the analysed plants is related to plant functionality, with longer chain lengths associated with higher drought adaptive capacities, probably as a response to long-term evolutionary processes in a moisture limited environment. Furthermore, species with relatively higher average chain lengths (ACL) showed more enriched carbon isotope composition in their tissues (δ13Cplant), suggesting a dual imprint from both physiological and biochemical drought adaptation. The findings have bearings on interpretation of fossil sedimentary biomarker records in the Mediterranean region, which is discussed in relation to a case study from Agios Floros fen, Messenian plain, Peloponnese. The 6000 year long n-alkane record from Agios Floros (ACL, δ13Cwax) is linked to the modern analogue and then evaluated through a comparison with other regional-wide as well as local climate and vegetation proxy-data. The high concentration of long chain n-alkanes in phrygana vegetation suggests a dominating imprint from this vegetation type in sedimentary archives from this ecotone.

Dissolved organic nitrogen dynamics in the North Sea: A time series analysis (1995-2005)

NASA Astrophysics Data System (ADS)

Van Engeland, T.; Soetaert, K.; Knuijt, A.; Laane, R. W. P. M.; Middelburg, J. J.

2010-09-01

Dissolved organic nitrogen (DON) dynamics in the North Sea was explored by means of long-term time series of nitrogen parameters from the Dutch national monitoring program. Generally, the data quality was good with little missing data points. Different imputation methods were used to verify the robustness of the patterns against these missing data. No long-term trends in DON concentrations were found over the sampling period (1995-2005). Inter-annual variability in the different time series showed both common and station-specific behavior. The stations could be divided into two regions, based on absolute concentrations and the dominant times scales of variability. Average DON concentrations were 11 μmol l -1 in the coastal region and 5 μmol l -1 in the open sea. Organic fractions of total dissolved nitrogen (TDN) averaged 38 and 71% in the coastal zone and open sea, respectively, but increased over time due to decreasing dissolved inorganic nitrogen (DIN) concentrations. In both regions intra-annual variability dominated over inter-annual variability, but DON variation in the open sea was markedly shifted towards shorter time scales relative to coastal stations. In the coastal zone a consistent seasonal DON cycle existed with high values in spring-summer and low values in autumn-winter. In the open sea seasonality was weak. A marked shift in the seasonality was found at the Dogger Bank, with DON accumulation towards summer and low values in winter prior to 1999, and accumulation in spring and decline throughout summer after 1999. This study clearly shows that DON is a dynamic actor in the North Sea and should be monitored systematically to enable us to understand fully the functioning of this ecosystem.

Cadmium accumulations and bioavailability in soils from long-term phosphorus fertilization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mulla, D.J.; Page, A.L.; Ganje, T.J.

1980-07-01

Soils from citrus groves that had been fertilized with the equivalent of approximately 175 kg P/ha per year (as treble superphosphate (TSP)) over a 36-year period were sampled and analyzed for total P, Cd, and Zn as well as water-soluble P and Cd. A P fertilization rate of 175 kg/ha is much higher than normal field rates, which are typically about 30 kg/ha. Concentrations of total Cd in surface soil were highly correlated (r = 0.89) with concentrations of total P. The concentrations of Cd in surface soil receiving broadcast P for 36 years averaged 1.0 ..mu..g/g, and were considerablymore » greater than those of the controls, which showed a mean concentration of 0.07 ..mu..g/g. Phosphorus in soil saturation paste extracts ranged from 0.10 ..mu..g/ml (controls) to 8.87 ..mu..g/ml in P fertilized soils. Water-soluble saturation extract Cd ranged from 0.008 ..mu..g/ml in controls to 0.017 ..mu..g/ml in fertilized soils, and was not well correlated with water-soluble P. Cadmium levels in barley (Hordeum vulgare var. U.C. 566) grain and leaves grown in the field on soil subject to long-term heavy P fertilization were not elevated above levels in barley grown on the control soil. Swiss chard (Beta vulgaris var. cicla) was grown in the greenhouse on the above surface soils collected from the field. Although Cd levels averaging 1.6 ..mu..g/g in plant tissue were significantly elevated over those on the control soil (0.26 ..mu..g/gm), no yield depression was observed.« less

DEVELOMENT AND EVALUATION OF A MODEL FOR ESTIMATING LONG-TERM AVERAGE OZONE EXPOSURES TO CHILDREN

EPA Science Inventory

Long-term average exposures of school-age children can be modelled using longitudinal measurements collected during the Harvard Southern California Chronic Ozone Exposure Study over a 12-month period: June, 1995-May, 1996. The data base contains over 200 young children with perso...

Long-term Changes in Extreme Air Pollution Meteorology and the Implications for Air Quality.

PubMed

Hou, Pei; Wu, Shiliang

2016-03-31

Extreme air pollution meteorological events, such as heat waves, temperature inversions and atmospheric stagnation episodes, can significantly affect air quality. Based on observational data, we have analyzed the long-term evolution of extreme air pollution meteorology on the global scale and their potential impacts on air quality, especially the high pollution episodes. We have identified significant increasing trends for the occurrences of extreme air pollution meteorological events in the past six decades, especially over the continental regions. Statistical analysis combining air quality data and meteorological data further indicates strong sensitivities of air quality (including both average air pollutant concentrations and high pollution episodes) to extreme meteorological events. For example, we find that in the United States the probability of severe ozone pollution when there are heat waves could be up to seven times of the average probability during summertime, while temperature inversions in wintertime could enhance the probability of severe particulate matter pollution by more than a factor of two. We have also identified significant seasonal and spatial variations in the sensitivity of air quality to extreme air pollution meteorology.

The moving-window Bayesian Maximum Entropy framework: Estimation of PM2.5 yearly average concentration across the contiguous United States

PubMed Central

Akita, Yasuyuki; Chen, Jiu-Chiuan; Serre, Marc L.

2013-01-01

Geostatistical methods are widely used in estimating long-term exposures for air pollution epidemiological studies, despite their limited capabilities to handle spatial non-stationarity over large geographic domains and uncertainty associated with missing monitoring data. We developed a moving-window (MW) Bayesian Maximum Entropy (BME) method and applied this framework to estimate fine particulate matter (PM2.5) yearly average concentrations over the contiguous U.S. The MW approach accounts for the spatial non-stationarity, while the BME method rigorously processes the uncertainty associated with data missingnees in the air monitoring system. In the cross-validation analyses conducted on a set of randomly selected complete PM2.5 data in 2003 and on simulated data with different degrees of missing data, we demonstrate that the MW approach alone leads to at least 17.8% reduction in mean square error (MSE) in estimating the yearly PM2.5. Moreover, the MWBME method further reduces the MSE by 8.4% to 43.7% with the proportion of incomplete data increased from 18.3% to 82.0%. The MWBME approach leads to significant reductions in estimation error and thus is recommended for epidemiological studies investigating the effect of long-term exposure to PM2.5 across large geographical domains with expected spatial non-stationarity. PMID:22739679

Predicting Long-Term College Success through Degree Completion Using ACT[R] Composite Score, ACT Benchmarks, and High School Grade Point Average. ACT Research Report Series, 2012 (5)

ERIC Educational Resources Information Center

Radunzel, Justine; Noble, Julie

2012-01-01

This study compared the effectiveness of ACT[R] Composite score and high school grade point average (HSGPA) for predicting long-term college success. Outcomes included annual progress towards a degree (based on cumulative credit-bearing hours earned), degree completion, and cumulative grade point average (GPA) at 150% of normal time to degree…

Semen Quality as a Predictor of Subsequent Morbidity: A Danish Cohort Study of 4,712 Men With Long-Term Follow-up.

PubMed

Latif, Tabassam; Kold Jensen, Tina; Mehlsen, Jesper; Holmboe, Stine Agergaard; Brinth, Louise; Pors, Kirsten; Skouby, Sven Olaf; Jørgensen, Niels; Lindahl-Jacobsen, Rune

2017-10-15

Semen quality has been suggested to be a biological marker of long-term morbidity and mortality; however, few studies have been conducted on this subject. We identified 5,370 men seen for infertility at Frederiksberg Hospital, Denmark, during 1977-2010, and 4,712 of these men were followed in the Danish National Patient Registry until first hospitalization, death, or the end of the study. We classified patients according to hospitalizations and the presence of cardiovascular disease, diabetes, testicular cancer, or prostate cancer. We found a clear association between sperm concentration below 15 million/mL and all-cause hospitalizations (hazard ratio = 1.5, 95% confidence interval: 1.4, 1.6) and cardiovascular disease (hazard ratio = 1.4, 95% confidence interval: 1.2, 1.6), compared with men with a concentration above 40 million/mL. The probabilities for hospitalizations were also higher with a low total sperm count and low motility. Men with a sperm concentration of 195-200 million/mL were, on average, hospitalized for the first time 7 years later than were men with a sperm concentration of 0-5 million/mL. Semen quality was associated with long-term morbidity, and a significantly higher risk of hospitalization was found, in particular for cardiovascular diseases and diabetes mellitus. Our study supports the suggestion that semen quality is a strong biomarker of general health. © The Author(s) 2017. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

The features of chlorophyll concentration long-standing dynamics in the ocean surface layer (comparison of czcs and seawifs data)

NASA Astrophysics Data System (ADS)

Shevyrnogov, A.; Vysotskaya, G.

To preserve biosphere and make its utilization expedient makes imperative to comprehend in depth long-standing dynamics of the primary production process on our planet. Variability of chlorophyll concentration in the ocean is one of the most important components of this process. However, hard access and large size of the water surface make its investigation labor-consuming. Besides, the dependence of primary production on high variability of hydrophysical phenomena in the ocean (fluctuations of currents, frontal zones, etc.) makes the location of points for measuring the chlorophyll concentration dynamics significant. In this work the long-standing changes in chlorophyll concentration in the surface layer of the ocean have been analyzed on the basis of the CZCS data for 7.5 years and the SeaWiFS data from 1997 to 2003. It was shown that the average chlorophyll concentration calculated at all investigated area is varied moderately. However when analyzing spatially local trends, it was detected that areas exist with stable rise and fall of chlorophyll concentration. Some interesting features of the long-standing dynamics of chlorophyll concentration several interesting features were found. There are the various directions of long-term trends (constant increase or decrease) that cannot be explained only by large-scale hydrological phenomena in the ocean (currents, upwellings etc.). The next feature is a difference between the trends revealed by using the CZCS data and the trends based on the SeaWiFS data. Thus, the obtained results allow the possibility of identification of the ocean biota role in the global biospheric gas exchange.

Contemporary Trends in the Acid-Base Status of the Two Acid-Sensitive Streams in Western Maryland

NASA Technical Reports Server (NTRS)

Eshleman, Keith N.; Kline, Kathleen M.; Morgan, Raymond P., II; Castro, Nancy M.; Negley, Timothy L.

2008-01-01

Recovery of streamwater acid neutralizing capacity (ANC) resulting from declines in regional acid deposition was examined using contemporary (1990-2005) data from two long-term monitoring stations located on the Appalachian Plateau in western Maryland, U.S. Two computational methods were used to estimate daily, monthly, and annual fluxes and discharge-weighted concentrations of ANC, sulfate, nitrate, and base cations over the period of record, and two statistical methods were used to evaluate long-term trends in fluxes and concentrations. The methods used to estimate concentrations, as well as the, statistical techniques, produced very similar results, underlining the robustness of the identified trends. We found clear evidence that streamwater sulfate concentrations have declined at an average rate of about 3 (microns)eq L(exp -1) yr(exp -1) at the two sites due to a 34% reduction in wet atmospheric sulfur deposition. Trends in nitrate concentrations appear to be related to other watershed factors, especially forest disturbance. The best evidence of recovery is based on a doubling of ANC (from 21 to 42 (microns)eq L(exp -1) at the more acid-sensitive site over the 16-year period. A slowing, or possible reversal, in the sulfate, nitrate, and SBC trends is evident in our data and may portend a decline in the rate of--or end to--further recovery.

Spatio-temporal modelling of residential exposure to particulate matter and gaseous pollutants for the Heinz Nixdorf Recall Cohort

NASA Astrophysics Data System (ADS)

Nonnemacher, Michael; Jakobs, Hermann; Viehmann, Anja; Vanberg, Irene; Kessler, Christoph; Moebus, Susanne; Möhlenkamp, Stefan; Erbel, Raimund; Hoffmann, Barbara; Memmesheimer, Michael

2014-07-01

For the simultaneous analysis of short- and long-term effects of air pollution in the Heinz Nixdorf Recall Cohort a sophisticated exposure modelling was performed. The dispersion and chemistry transport model EURAD (European Air Pollution Dispersion) was used for the estimation of hourly concentrations of a number of pollutants for a horizontal grid with a cell size of 1 km² covering the whole study area (three large adjacent cities in a highly urbanized region in Western Germany) for the years 2000-2003 and 2006-2008. For each 1 km² cell we estimated the mean concentration by calculating daily means from the hourly concentrations modelled by the EURAD process. The modelled concentrations showed an overall tendency to decrease from 2001 to 2008 whereas the trend in the single grid cells and study period was inhomogeneous. Participant-related exposure slightly increased from 2001 to 2003 followed by a decrease from 2006 to 2008. The exposure modelling enables a very flexible exposure assessment compared to conventional modelling approaches which either use central monitoring or temporally static spatial contrasts. The modelling allows the calculation of an average exposure concentration for any place and time within the study region and study period with a high spatial and temporal resolution. This is important for the assessment of short-, medium and long-term effects of air pollution on human health in epidemiological studies.

Long-term increases in young-of-the-year growth of Arctic cisco Coregonus autumnalis and environmental influences.

PubMed

von Biela, V R; Zimmerman, C E; Moulton, L L

2011-01-01

Arctic cisco Coregonus autumnalis young-of-year (YOY) growth was used as a proxy to examine the long-term response of a high-latitude fish population to changing climate from 1978 to 2004. YOY growth increased over time (r² = 0·29) and was correlated with monthly averages of the Arctic oscillation index, air temperature, east wind speed, sea-ice concentration and river discharge with and without time lags. Overall, the most prevalent correlates to YOY growth were sea-ice concentration lagged 1 year (significant correlations in 7 months; r² = 0·14-0·31) and Mackenzie River discharge lagged 2 years (significant correlations in 8 months; r² = 0·13-0·50). The results suggest that decreased sea-ice concentrations and increased river discharge fuel primary production and that life cycles of prey species linking increased primary production to fish growth are responsible for the time lag. Oceanographic studies also suggest that sea ice concentration and fluvial inputs from the Mackenzie River are key factors influencing productivity in the Beaufort Sea. Future research should assess the possible mechanism relating sea ice concentration and river discharge to productivity at upper trophic levels. Journal of Fish Biology © 2010 The Fisheries Society of the British Isles. No claim to original US government works.

Historical Prediction Modeling Approach for Estimating Long-Term Concentrations of PM2.5 in Cohort Studies before the 1999 Implementation of Widespread Monitoring.

PubMed

Kim, Sun-Young; Olives, Casey; Sheppard, Lianne; Sampson, Paul D; Larson, Timothy V; Keller, Joshua P; Kaufman, Joel D

2017-01-01

Recent cohort studies have used exposure prediction models to estimate the association between long-term residential concentrations of fine particulate matter (PM2.5) and health. Because these prediction models rely on PM2.5 monitoring data, predictions for times before extensive spatial monitoring present a challenge to understanding long-term exposure effects. The U.S. Environmental Protection Agency (EPA) Federal Reference Method (FRM) network for PM2.5 was established in 1999. We evaluated a novel statistical approach to produce high-quality exposure predictions from 1980 through 2010 in the continental United States for epidemiological applications. We developed spatio-temporal prediction models using geographic predictors and annual average PM2.5 data from 1999 through 2010 from the FRM and the Interagency Monitoring of Protected Visual Environments (IMPROVE) networks. Temporal trends before 1999 were estimated by using a) extrapolation based on PM2.5 data in FRM/IMPROVE, b) PM2.5 sulfate data in the Clean Air Status and Trends Network, and c) visibility data across the Weather Bureau Army Navy network. We validated the models using PM2.5 data collected before 1999 from IMPROVE, California Air Resources Board dichotomous sampler monitoring (CARB dichot), the Children's Health Study (CHS), and the Inhalable Particulate Network (IPN). In our validation using pre-1999 data, the prediction model performed well across three trend estimation approaches when validated using IMPROVE and CHS data (R2 = 0.84-0.91) with lower R2 values in early years. Model performance using CARB dichot and IPN data was worse (R2 = 0.00-0.85) most likely because of fewer monitoring sites and inconsistent sampling methods. Our prediction modeling approach will allow health effects estimation associated with long-term exposures to PM2.5 over extended time periods ≤ 30 years. Citation: Kim SY, Olives C, Sheppard L, Sampson PD, Larson TV, Keller JP, Kaufman JD. 2017. Historical prediction modeling approach for estimating long-term concentrations of PM2.5 in cohort studies before the 1999 implementation of widespread monitoring. Environ Health Perspect 125:38-46; http://dx.doi.org/10.1289/EHP131.

Estimation of streamflow, base flow, and nitrate-nitrogen loads in Iowa using multiple linear regression models

USGS Publications Warehouse

Schilling, K.E.; Wolter, C.F.

2005-01-01

Nineteen variables, including precipitation, soils and geology, land use, and basin morphologic characteristics, were evaluated to develop Iowa regression models to predict total streamflow (Q), base flow (Qb), storm flow (Qs) and base flow percentage (%Qb) in gauged and ungauged watersheds in the state. Discharge records from a set of 33 watersheds across the state for the 1980 to 2000 period were separated into Qb and Qs. Multiple linear regression found that 75.5 percent of long term average Q was explained by rainfall, sand content, and row crop percentage variables, whereas 88.5 percent of Qb was explained by these three variables plus permeability and floodplain area variables. Qs was explained by average rainfall and %Qb was a function of row crop percentage, permeability, and basin slope variables. Regional regression models developed for long term average Q and Qb were adapted to annual rainfall and showed good correlation between measured and predicted values. Combining the regression model for Q with an estimate of mean annual nitrate concentration, a map of potential nitrate loads in the state was produced. Results from this study have important implications for understanding geomorphic and land use controls on streamflow and base flow in Iowa watersheds and similar agriculture dominated watersheds in the glaciated Midwest. (JAWRA) (Copyright ?? 2005).

Statistical persistence of air pollutants (O3,SO2,NO2 and PM10) in Mexico City

NASA Astrophysics Data System (ADS)

Meraz, M.; Rodriguez, E.; Femat, R.; Echeverria, J. C.; Alvarez-Ramirez, J.

2015-06-01

The rescaled range (R / S) analysis was used for analyzing the statistical persistence of air pollutants in Mexico City. The air-pollution time series consisted of hourly observations of ozone, nitrogen dioxide, sulfur dioxide and particulate matter obtained at the Mexico City downtown monitoring station during 1999-2014. The results showed that long-range persistence is not a uniform property over a wide range of time scales, from days to months. In fact, although the air pollutant concentrations exhibit an average persistent behavior, environmental (e.g., daily and yearly) and socio-economic (e.g., daily and weekly) cycles are reflected in the dependence of the persistence strength as quantified in terms of the Hurst exponent. It was also found that the Hurst exponent exhibits time variations, with the ozone and nitrate oxide concentrations presenting some regularity, such as annual cycles. The persistence dynamics of the pollutant concentrations increased during the rainy season and decreased during the dry season. The time and scale dependences of the persistence properties provide some insights in the mechanisms involved in the internal dynamics of the Mexico City atmosphere for accumulating and dissipating dangerous air pollutants. While in the short-term individual pollutants dynamics seems to be governed by specific mechanisms, in the long-term (for monthly and higher scales) meteorological and seasonal mechanisms involved in atmospheric recirculation seem to dominate the dynamics of all air pollutant concentrations.

[The applicable study of two models used in the assessment of long-term exposure to food lead].

PubMed

Jin, Ying-liang; Zhang, Ya-fei; Liu, Pei

2013-07-01

To compare the results of observed individual means (OIM) model with beta binomial-normal (BBN) model and to apply the two models to assessment of long-term dietary lead exposure. Food consumption data were obtained from the National Nutrition and Health Survey conducted in 2002 by 24-hour recall method. Contamination data were derived from the national food contamination monitoring program from 2000 to 2006 and from monitoring data of Customs exports for agricultural products between 2005 and 2006. By multiplying the average consumption of food with the average concentration of contaminant, the OIM model calculated dietary intake per day. By correcting the within-person variation and keeping the between-person variation, the BBN model built dietary intake in the long-term.Using the example of food lead data, the results of two models were compared. The high-end percentile of OIM model was higher than the BBN model in various age groups.In the general population, the dietary intake of OIM model from 25th percentile to 99.9th percentile was between 1.167 and 7.313 µg×kg(-1)×d(-1), and the dietary intake of BBN model with the same percentile range was between 1.193 and 5.729 µg×kg(-1)×d(-1). The median of various groups was similar between the two models. The dietary intakes in the general population of two models were 1.543 and 1.579 µg×kg(-1)×d(-1). The high-end percentile of OIM model is more conservative than BBN model in the long-term dietary exposure assessment.

Latent effect of soil organic matter oxidation on mercury cycling within a southern boreal ecosystem.

PubMed

Gabriel, Mark; Kolka, Randy; Wickman, Trent; Woodruff, Laurel; Nater, Ed

2012-01-01

The focus of this study is to investigate processes causing the observed spatial variation of total mercury (THg) in the soil O horizon of watersheds within the Superior National Forest (Minnesota) and to determine if results have implications toward understanding long-term changes in THg concentrations for resident fish. Principal component analysis was used to evaluate the spatial relationships of 42 chemical elements in three soil horizons over 10 watersheds. Results indicate that soil organic carbon is the primary factor controlling the spatial variation of certain metals (Hg, Tl, Pb, Bi, Cd, Sn, Sb, Cu, and As) in the O and A soil horizons. In the B/E horizon, organic carbon appeared to play a minor role in metal spatial variation. These characteristics are consistent with the concentration of soil organic matter and carbon decreasing from the O to the B/E horizons. We also investigated the relationship between percent change in upland soil organic content and fish THg concentrations across all watersheds. Statistical regression analysis indicates that a 50% reduction in age-one and age-two fish THg concentration could result from an average 10% decrease in upland soil organic content. Disturbances that decrease the content of THg and organic matter in the O and A horizons (e.g., fire) may cause a short-term increase in atmospherically deposited mercury but, over the long term, may lead to decreased fish THg concentrations in affected watersheds. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Long-term exposure to high air pollution induces cumulative DNA damages in traffic policemen.

PubMed

Tan, Chaochao; Lu, Shijie; Wang, Yupeng; Zhu, Yan; Shi, Ting; Lin, Mingyue; Deng, Zhonghua; Wang, Zhu; Song, Nana; Li, Shuna; Yang, Pingting; Yang, Liyan; Liu, Yuanyuan; Chen, Zhiheng; Xu, Keqian

2017-09-01

The specific effects of long-term exposure to high air pollution on human health and biological remain unclear. To explore the adverse health effects as well as biological mechanisms and biomarkers for durative exposure to air pollution, 183 traffic policemen and 88 office policemen were enrolled in this study. The concentration of PM2.5 in both the traffic and office policemen's working environments were obtained. Detailed personal questionnaires were completed and levels of inflammation, oxidative stress and DNA damage markers of all participants were analyzed in this study. The average PM2.5 concentration of the intersections of main roads and the offices of control group were 132.4±48.9μg/m 3 and 50.80±38.6μg/m 3 , respectively. The traffic policemen, who stably exposed to at least 2 times higher PM2.5 in their work area as compared with the control group, have a median average duration of 7.00years, and average cumulative intersection duty time reached 8030h. No statistically significant differences in the levels of inflammation markers were observed between the traffic and office policemen. However, the DNA damage markers in traffic policemen shared significant positive correlation with cumulative intersection duty time and higher than those in the office policemen. Multiple linear regression analysis demonstrated that the increase of cumulative intersection duty time by 1h per day for one year was associated with the increase in 8-hydroxy-20-deoxyguanosine of 0.329% (95% CI: 0.249% to 0.409%), tail DNA of 0.051% (95% CI: 0.041% to 0.061%), micronucleus frequency of 0.036‰ (95% CI: 0.03‰ to 0.043‰), and a decrease in glutathione of 0.482% (95% CI: -0.652% to -0.313%). These findings suggest that long-term exposure to high air pollution could induce cumulative DNA damages, supporting the hypothesis that durative exposure to air pollution is associated with an increased risk of cancer. Copyright © 2017 Elsevier B.V. All rights reserved.

Dynamic evaluation of two decades of WRF-CMAQ ozone simulations over the contiguous United States

NASA Astrophysics Data System (ADS)

Astitha, Marina; Luo, Huiying; Rao, S. Trivikrama; Hogrefe, Christian; Mathur, Rohit; Kumar, Naresh

2017-09-01

Dynamic evaluation of the fully coupled Weather Research and Forecasting (WRF)- Community Multi-scale Air Quality (CMAQ) model ozone simulations over the contiguous United States (CONUS) using two decades of simulations covering the period from 1990 to 2010 is conducted to assess how well the changes in observed ozone air quality are simulated by the model. The changes induced by variations in meteorology and/or emissions are also evaluated during the same timeframe using spectral decomposition of observed and modeled ozone time series with the aim of identifying the underlying forcing mechanisms that control ozone exceedances and making informed recommendations for the optimal use of regional-scale air quality models. The evaluation is focused on the warm season's (i.e., May-September) daily maximum 8-hr (DM8HR) ozone concentrations, the 4th highest (4th) and average of top 10 DM8HR ozone values (top10), as well as the spectrally-decomposed components of the DM8HR ozone time series using the Kolmogorov-Zurbenko (KZ) filter. Results of the dynamic evaluation are presented for six regions in the U.S., consistent with the National Oceanic and Atmospheric Administration (NOAA) climatic regions. During the earlier 11-yr period (1990-2000), the simulated and observed regional average trends are not statistically significant. During the more recent 2000-2010 period, all observed trends are statistically significant and WRF-CMAQ captures the observed downward trend in the Southwest and Midwest but under-predicts the downward trends in observations for the other regions. Observational analysis reveals that it is the magnitude of the long-term forcing that dictates the maximum ozone exceedance potential; there is a strong linear relationship between the long-term forcing and the 4th highest or the average of the top10 ozone concentrations in both observations and model output. This finding indicates that improving the model's ability to reproduce the long-term component will also enable better simulation of ozone extreme values that are of interest to regulatory agencies.

26 CFR 5c.1305-1 - Special income averaging rules for taxpayers otherwise required to compute tax in accordance with...

Code of Federal Regulations, 2013 CFR

2013-04-01

... subject to section 1256(a). Of that total, 40 percent is short term capital gain ($375,000) and 60 percent is long term capital gain ($562,500). Of the long term capital gain, 40 percent is taxable ($225,000... INCOME TAX REGULATIONS UNDER THE ECONOMIC RECOVERY TAX ACT OF 1981 § 5c.1305-1 Special income averaging...

26 CFR 5c.1305-1 - Special income averaging rules for taxpayers otherwise required to compute tax in accordance with...

Code of Federal Regulations, 2011 CFR

2011-04-01

... subject to section 1256(a). Of that total, 40 percent is short term capital gain ($375,000) and 60 percent is long term capital gain ($562,500). Of the long term capital gain, 40 percent is taxable ($225,000... INCOME TAX REGULATIONS UNDER THE ECONOMIC RECOVERY TAX ACT OF 1981 § 5c.1305-1 Special income averaging...

26 CFR 5c.1305-1 - Special income averaging rules for taxpayers otherwise required to compute tax in accordance with...

Code of Federal Regulations, 2010 CFR

2010-04-01

... subject to section 1256(a). Of that total, 40 percent is short term capital gain ($375,000) and 60 percent is long term capital gain ($562,500). Of the long term capital gain, 40 percent is taxable ($225,000... INCOME TAX REGULATIONS UNDER THE ECONOMIC RECOVERY TAX ACT OF 1981 § 5c.1305-1 Special income averaging...

26 CFR 5c.1305-1 - Special income averaging rules for taxpayers otherwise required to compute tax in accordance with...

Code of Federal Regulations, 2014 CFR

2014-04-01

... subject to section 1256(a). Of that total, 40 percent is short term capital gain ($375,000) and 60 percent is long term capital gain ($562,500). Of the long term capital gain, 40 percent is taxable ($225,000... INCOME TAX REGULATIONS UNDER THE ECONOMIC RECOVERY TAX ACT OF 1981 § 5c.1305-1 Special income averaging...

26 CFR 5c.1305-1 - Special income averaging rules for taxpayers otherwise required to compute tax in accordance with...

Code of Federal Regulations, 2012 CFR

2012-04-01

... subject to section 1256(a). Of that total, 40 percent is short term capital gain ($375,000) and 60 percent is long term capital gain ($562,500). Of the long term capital gain, 40 percent is taxable ($225,000... INCOME TAX REGULATIONS UNDER THE ECONOMIC RECOVERY TAX ACT OF 1981 § 5c.1305-1 Special income averaging...

Influence of endurance and sprinting exercise on plasma adiponectin, leptin and irisin concentrations in racing Greyhounds and sled dogs.

PubMed

Bell, M A; Levine, C B; Downey, R L; Griffitts, C; Mann, S; Frye, C W; Wakshlag, J J

2016-05-01

The objective of this study was to assess the effects of both short-term anaerobic exercise and long-term aerobic exercise on leptin, adiponectin and irisin concentrations in both sprint and endurance canine athletes. Prospective field trial repeated measures. The 25 racing Greyhounds were run over 400 m, with blood samples collected prior to exercise and at 10 min and 120 min after exercise. The 16 sled dogs were run an average of 3.5-5 h/day on 5 out of 8 days of stage stop racing competition, with assessment on days 0, 2 and 8. Baseline leptin concentrations were found to be lower than previously recorded values of domestic dogs, possibly because of a lower body fat content in athletes, with concentrations in sled dogs being slightly higher than those in Greyhounds. Baseline adiponectin concentrations in both groups of dogs, on average, were lower than most previously recorded values in domestic dogs; although unexpected, these findings may be attributed to differences in body fat content of the study population. Endurance exercise in sled dogs resulted in a persistent decrease in leptin that appears to be independent of race-associated weight loss, with no appreciable changes in adiponectin or irisin concentrations. The anaerobic exercise of Greyhounds produced no detectable changes in leptin and adiponectin concentrations; however, a significant rise in irisin 10 min post-exercise may be a compensatory mechanism for restoration of ATP homeostasis in skeletal muscle. © 2016 Australian Veterinary Association.

Direct damage to vegetation caused by acid rain and polluted cloud: definition of critical levels for forest trees.

PubMed

Cape, J N

1993-01-01

The concept of critical levels was developed in order to define short-term and long-term average concentrations of gaseous pollutants above which plants may be damaged. Although the usual way in which pollutants in precipitation (wet deposition) influence vegetation is by affecting soil processes, plant foliage exposed to fog and cloud, which often contain much greater concentrations of pollutant ions than rain, may be damaged directly. The idea of a critical level has been extended to define concentrations of pollutants in wet deposition above which direct damage to plants is likely. Concentrations of acidity and sulphate measured in mountain and coastal cloud are summarised. Vegetation at risk of injury is identified as montane forest growing close to the cloud base, where ion concentrations are highest. The direct effects of acidic precipitation on trees are reviewed, based on experimental exposure of plants to simulated acidic rain, fog or mist. Although most experiments have reported results in terms of pH (H(+) concentration), the accompanying anion is important, with sulphate being more damaging than nitrate. Both conifers and broadleaved tree seedlings showing subtle changes in the structural characteristics of leaf surfaces after exposure to mist or rain at or about pH 3.5, or sulphate concentration of 150 micromol litre(-1). Visible lesions on leaf surfaces occur at around pH 3 (500 micromol litre(-1) sulphate), broadleaved species tending to be more sensitive than conifers. Effects on photosynthesis and water relations, and interactions with other stresses (e.g. frost), have usually been observed only for treatments which have also caused visible injury to the leaf surface. Few experiments on the direct effects of polluted cloud have been conducted under field conditions with mature trees, which unlike seedlings in controlled conditions, may suffer a growth reduction in the absence of visible injury. Although leaching of cations (Ca(2+), Mg(2+), K(+)) is stimulated by acidic precipitation, amounts leached are small compared with root uptake, unless soils have been impoverished. This aspect of the potential effects of acidic precipitation is best considered in terms of the long-term critical-load of pollutants to the soil. Given the practical difficulties in monitoring cloud water composition, a method for defining critical levels is proposed, which uses climatological average data to identify the duration and frequency of hill cloud, and combines this information with measured or modelled concentrations of particulate sulphate in the atmosphere, to derive cloud water concentrations as a function of cloud liquid water content. For forests within 100 m of the cloud base the critical levels of particulate sulphate, corresponding to solution concentrations in the range 150-500 micromol litre(-1), are in the range 1-3.3 microg S m(-3). These concentrations are observed over much of central Europe, suggesting that many montane forests are at risk of direct effects of fossil-fuel-derived pollutants in cloud.

Are groundwater nitrate concentrations reaching a turning point in some chalk aquifers?

PubMed

Smith, J T; Clarke, R T; Bowes, M J

2010-09-15

In past decades, there has been much scientific effort dedicated to the development of models for simulation and prediction of nitrate concentrations in groundwaters, but producing truly predictive models remains a major challenge. A time-series model, based on long-term variations in nitrate fertiliser applications and average rainfall, was calibrated against measured concentrations from five boreholes in the River Frome catchment of Southern England for the period spanning from the mid-1970s to 2003. The model was then used to "blind" predict nitrate concentrations for the period 2003-2008. To our knowledge, this represents the first "blind" test of a model for predicting nitrate concentrations in aquifers. It was found that relatively simple time-series models could explain and predict a significant proportion of the variation in nitrate concentrations in these groundwater abstraction points (R(2)=0.6-0.9 and mean absolute prediction errors 4.2-8.0%). The study highlighted some important limitations and uncertainties in this, and other modelling approaches, in particular regarding long-term nitrate fertiliser application data. In three of the five groundwater abstraction points (Hooke, Empool and Eagle Lodge), once seasonal variations were accounted for, there was a recent change in the generally upward historical trend in nitrate concentrations. This may be an early indication of a response to levelling-off (and declining) fertiliser application rates since the 1980s. There was no clear indication of trend change at the Forston and Winterbourne Abbas sites nor in the trend of nitrate concentration in the River Frome itself from 1965 to 2008. Copyright 2010 Elsevier B.V. All rights reserved.

Nutrient loading to Lewisville Lake, north-central Texas, 1984-87

USGS Publications Warehouse

Gain, W.S.; Baldys, Stanley

1995-01-01

The estimated long-term (1974-89 water years) average annual total nitrogen load (excluding loads from sewage-treatment plants in ungaged areas) is 11,800 pounds per day. The estimated long-term (1974 89 water years) average annual total phosphorus load (excluding loads from sewage-treatment plants in ungaged areas) is 1,100 pounds per day.

Remediation and its effect represented on long term monitoring data at a chlorinated ethenes contaminated site, Wonju, Korea

NASA Astrophysics Data System (ADS)

Lee, Seong-Sun; Lee, Seung Hyun; Lee, Kang-Kun

2016-04-01

A research for the contamination of chlorinated ethenes such as trichloroethylene (TCE) at an industrial complex, Wonju, Korea, was carried out based on 17 rounds of groundwater quality data collection from 2009 to 2015. Remediation technologies such as soil vapor extraction, soil flushing, biostimulation, and pump-and-treat have been applied to eliminate the contaminant sources of trichloroethylene (TCE) and to prevent the migration of TCE plume from remediation target zones to groundwater discharge area like a stream. The remediation efficiency according to the remedial actions was evaluated by tracing a time-series of plume evaluation and temporal mass discharge at three transects (Source, Transect-1, Transect-2) which was assigned along the groundwater flow path. Also, based on long term monitoring data, dissolved TCE concentration and mass of residual TCE in the initial stage of disposal were estimated to evaluate the efficiency of in situ remediation. The results of temporal and spatial monitoring before remedial actions showed that a TCE plume originating from main and local source zones continues to be discharged to a stream. However, from the end of intensive remedial actions from 2012 to 2013, the aqueous concentrations of TCE plume present at and around the main source areas decreased significantly. Especially, during the intensive remediation period, the early average mass discharge (26.58 g/day) at source transect was decreased to average 4.99 g/day. Estimated initial dissolved concentration and residual mass of TCE in the initial stage of disposal decreased rapidly after an intensive remedial action in 2013 and it is expected to be continuously decreased from the end of remedial actions to 2020. This study demonstrates that long term monitoring data are useful in assessing the effectiveness of remedial actions at chlorinated ethenes contaminated site. Acknowledgements This project is supported by the Korea Ministry of Environment under "The GAIA Project (173-092-009)"and "R&D Project on Environmental Management of Geologic CO2 storage" from the KEITI (Project number:2014001810003).

Association between PM10 concentrations and school absences in proximity of a cement plant in northern Italy.

PubMed

Marcon, Alessandro; Pesce, Giancarlo; Girardi, Paolo; Marchetti, Pierpaolo; Blengio, Gianstefano; de Zolt Sappadina, Simona; Falcone, Salvatore; Frapporti, Guglielmo; Predicatori, Francesca; de Marco, Roberto

2014-03-01

Dusts are one of the main air pollutants emitted during cement manufacturing. A substantial part of these are breathable particles that are less than 10 μm in diameter (PM10), which represent a potential threat for the health of the exposed population. This study aimed at evaluating the short-term effects of PM10 concentrations on the health of children, aged 6-14 years, who attended the schools in Fumane (Italy), in proximity (1.2 km) to a large cement plant. School absenteeism was used as a proxy indicator of child morbidity. Time series of daily school absences and PM10 concentrations were collected for 3 school-years from 2007 to 2010 (541 school-days, 462 children on average). The associations between PM10 concentrations and school absence rates in the same day (lag0) and in the following 4 days (lag1 to lag4) were evaluated using generalised additive models, smoothed for medium/long term trends and adjusted for day of the week, influenza outbreaks, daily temperature and rain precipitations. The average concentration of PM10 in the period was 34 (range: 4-183) μg/m(3). An average 10 μg/m(3) increase of PM10 concentration in the previous days (lag0-4) was associated with a statistically significant 2.5% (95%CI: 1.1-4.0%) increase in the rate of school absences. The highest increase in the absence rates (2.4%; 95%CI: 1.2-3.5%) was found 2 days after exposure (lag2). These findings provide epidemiological evidence of the acute health effects of PM10 in areas with annual concentrations that are lower than the legal European Union limit of 40 μg/m(3), and support the need to establish more restrictive legislative standards. Copyright © 2013 Elsevier GmbH. All rights reserved.

Chemical characteristics and temporal trends in eight streams of the Catskill Mountains, New York

USGS Publications Warehouse

Murdoch, Peter S.; Stoddard, J.L.

1993-01-01

Discharge to concentration relationships for eight streams studied by the U.S. Geological Survey (USGS) as part of the U.S. Environmental Protection Agency's (U.S. EPA) Long-Term Monitoring Project (1983-89) indicate acidification of some streams by H2SO4 and HNO3 in atmospheric deposition and by organic acids in soils. Concentrations of major ions in precipitation were similar to those reported at other sites in the northeastern United States. Average concentrations of SO42- and NO3- were similar among streams, but base cation concentrations differed widely, and these differences paralleled the differences in acid neutralizing capacity (ANC). Baseflow ANC is not a reliable predictor of stream acidity at high flow; some streams with high baseflow ANC (> 150 ??eq L-1) declined to near zero ANC at high flow, and one stream with low baseflow ANC (< 50 ??eq L-1) did not approach zero ANC as flow increased. Episodic decreases in ANC and pH during peak flows were associated with increased concentrations of NO3- and dissolved organic carbon (DOC). Aluminum concentrations exceeding 300 ??g L-1 were observed during peak flows in headwater streams of the Neversink River and Rondout Creek. Seasonal Kendall Tau tests for temporal trends indicate that SO42- concentrations in streamwater generally decreased and NO3- concentrations increased during the period 1983-1989. Combined acid anion concentrations (SO42- + NO3-) were generally unchanged throughout the period of record, indicating both that the status of these streams with respect to acidic deposition is unchanged, and that NO3- is gradually replacing SO42- as the dominant acid anion in the Catskill streams.Discharge to concentration relationships for eight streams studied by the US Geological Survey (USGS) as part of the Environmental Protection Agency's (US EPA) Long-term monitoring project (19831-89) indicate acidification of some streams by H2SO4 and HNO3 in atmospheric deposition and by organic acids in soils. Concentrations of major ions in precipitations were similar to those reported at other sites in the northeastern United States. Average concentrations of SO42- and No3- were similar among streams, but base cation concentrations differed widely, and these differences parallelel the differences in acid neutralizing capacity (ANC).

Long-term monitoring of atmospheric PCDD/Fs at Mount Lulin during spring season: PCDD/F source apportionment through a simultaneous measurement in Southeast Asia.

PubMed

Hung, Ngo Tuan; Li, Chueh Ting; Wang, Sheng Hsiang; Ou-Yang, Chang-Feng; Lin, Chuan-Yao; Lee, Chung-Te; Lin, Neng-Huei; Chi, Kai Hsien

2017-10-01

A long term assessment of atmospheric polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) at Mt. Lulin, located in center of Taiwan was carried out from 2008 to 2013 (n = 81) assuming Mt. Lulin to be background area. During monitoring processes, PCDD/F samples collected in the field occasionally reached high concentration. To investigate this situation, simultaneous sample collection was carried out in Southeast Asia countries (i.e., Vietnam and Thailand) and Taiwan in 2013. The average concentration of atmospheric PCDD/Fs in biomass-burning source regions, namely Son La and Doi Ang Khang were 19.8 ± 12.1 fg I-TEQ m -3 (n = 19) and 17.8 ± 12.4 fg I-TEQ m -3 (n = 20), respectively. In the downwind area of Mt. Lulin, the average concentration of PCDD/Fs was found to be 4.64 ± 3.77 fg I-TEQ m -3 (n = 18). PCDD/F concentration in the source region was much higher than that in the downwind region. On March 19, 2013, the atmospheric PCDD/F concentrations increased dramatically from 7.71 to 484 fg I-TEQ m -3 at Mt. Lulin, which many times exceeded that of assumed source region in Southeast Asia. Moreover, mainland Southeast Asia and the southeast coast of China was suspected to be the main contributors of atmospheric PCDD/Fs and biomass markers, such as nonsea-salt K + and NH 4 + , during the spring. WRF-Chem and Potential Source Contribution Function (PSCF) simulations have confirmed this correlation. It can be concluded that atmospheric PCDD/Fs observed at Mt. Lulin during spring mostly derived from the air mass transport not only from Southeast Asia but also the southeast coast of China. Copyright © 2017 Elsevier Ltd. All rights reserved.

Hydrogeology, water quality, and simulated effects of ground-water withdrawals from the Floridan aquifer system, Seminole County and vicinity, Florida

USGS Publications Warehouse

Spechler, Rick M.; Halford, Keith J.

2001-01-01

The hydrogeology and ground-water quality of Seminole County in east-central Florida was evaluated. A ground-water flow model was developed to simulate the effects of both present day (September 1996 through August 1997) and projected 2020 ground-water withdrawals on the water levels in the surficial aquifer system and the potentiometric surface of the Upper and Lower Floridan aquifers in Seminole County and vicinity. The Floridan aquifer system is the major source of ground water in the study area. In 1965, ground-water withdrawals from the Floridan aquifer system in Seminole County were about 11 million gallons per day. In 1995, withdrawals totaled about 69 million gallons per day. Of the total ground water used in 1995, 74 percent was for public supply, 12 percent for domestic self-supplied, 10 percent for agriculture self-supplied, and 4 percent for recreational irrigation. The principal water-bearing units in Seminole County are the surficial aquifer system and the Floridan aquifer system. The two aquifer systems are separated by the intermediate confining unit, which contains beds of lower permeability sediments that confine the water in the Floridan aquifer system. The Floridan aquifer system has two major water-bearing zones (the Upper Floridan aquifer and the Lower Floridan aquifer), which are separated by a less-permeable semiconfining unit. Upper Floridan aquifer water levels and spring flows have been affected by ground-water development. Long-term hydrographs of four wells tapping the Upper Floridan aquifer show a general downward trend from the early 1950's until 1990. The declines in water levels are caused predominantly by increased pumpage and below average annual rainfall. From 1991 to 1998, water levels rose slightly, a trend that can be explained by an increase in average annual rainfall. Long-term declines in the potentiometric surface varied throughout the area, ranging from about 3 to 12 feet. Decreases in spring discharge also have been observed in a few springs with long-term record. Chloride concentrations in water from the Upper Floridan aquifer in Seminole County range areally from 6.2 to 5,300 milligrams per liter. Chloride concentrations are lowest in the recharge areas of the Floridan aquifer system in the western part of Seminole County and near Geneva. The most highly mineralized water occurs adjacent to the Wekiva River in northwestern Seminole County, around the eastern part of Lake Jesup, and along the St. Johns River in eastern Seminole County. Analysis of limited long-term water-quality data indicates that the chloride concentrations in water for most wells in the Floridan aquifer system in Seminole County have not changed significantly in the 20-year period from 1976 to 1996, and probably not since the mid 1950's. Analysis of water samples collected from some Upper Floridan aquifer springs, however, indicates that the water has become more mineralized during recent years. Increases in specific conductance and concentrations of major cations and anions were observed at several of the springs within the study area where long-term water-quality data were available. Associated with these increases in the mineralization of spring water has been an increase in total nitrate-plus- nitrite as nitrogen concentration. A three-dimensional model was developed to simulate ground-water flow in the surficial and Floridan aquifer systems. The steady-state ground-water flow model was calibrated to water-level data that was averaged over a 1-year period from September 1996 through August 1997. The calibrated flow model generally produced simulated water levels in reasonably close agreement with measured water levels. As a result, the calibrated model was used to simulate the effects of expected increases in ground-water withdrawals on the water levels in the surficial aquifer system and on the potentiometric surface of the Upper and Lower Floridan aquifers in Seminole County. The ca

Temporal dynamics of CO2 fluxes and profiles over a Central European city

NASA Astrophysics Data System (ADS)

Vogt, R.; Christen, A.; Rotach, M. W.; Roth, M.; Satyanarayana, A. N. V.

2006-02-01

In Summer 2002 eddy covariance flux measurements of CO2 were performed over a dense urban surface. The month-long measurements were carried out in the framework of the Basel Urban Boundary Layer Experiment (BUBBLE). Two Li7500 open path analysers were installed at z/z H = 1.0 and 2.2 above a street canyon with z H the average building height of 14.6 m and z the height above street level. Additionally, profiles of CO2 concentration were sampled at 10 heights from street level up to 2 z H . The minimum and maximum of the average diurnal course of CO2 concentration at 2 z H were 362 and 423 ppmv in late afternoon and early morning, respectively. Daytime CO2 concentrations were not correlated to local sources, e.g. the minimum occurred together with the maximum in traffic load. During night-time CO2 is in general accumulated, except when inversion development is suppressed by frontal passages. CO2 concentrations were always decreasing with height and correspondingly, the fluxes on average always directed upward. At z/z H = 2.2 low values of about 3 µmol m-2 s-1 were measured during the second half of the night. During daytime average values reached up to 14 µmol m-2 s-1. The CO2 fluxes are well correlated with the traffic load, with their maxima occurring together in late afternoon. Daytime minimum CO2 concentrations fell below regional background values. Besides vertical mixing and entrainment, it is suggested that this is also due to advection of rural air with reduced CO2 concentration. Comparison with other urban observations shows a large range of differences among urban sites in terms of both CO2 fluxes and concentrations.

A long-term copper exposure in a freshwater ecosystem using lotic mesocosms: Invertebrate community responses

USGS Publications Warehouse

Joachim, Sandrine; Roussel, Hélène; Bonzom, Jean-Marc; Thybaud, Eric; Mebane, Christopher A.; Brink, Paul Van den; Gauthier, Laury

2017-01-01

A lotic mesocosm study was carried out in 20-m-long channels, under continuous, environmentally realistic concentrations of copper (Cu) in low, medium, and high exposures (nominally 0, 5, 25, and 75 μg L−1; average effective concentrations <0.5, 4, 20, and 57 μg L−1 respectively) for 18 mo. Total abundance, taxa richness, and community structure of zooplankton, macroinvertebrates, and emerging insects were severely affected at Cu treatment levels of 25 and 75 μg L−1. Some taxa were sensitive to Cu, including gastropods such as Lymnaea spp. and Physasp., crustaceans such as Chydorus sphaericus, Gammarus pulex, and Asellus aquaticus, rotifers such as Mytilina sp. and Trichocerca sp., leeches such as Erpobdella sp., and the emergence of dipteran insects such as Chironomini. Other taxa appeared to be tolerant or favored by indirect effects, as in Chironimidae larvae, the emergence of Orthocladiinae, and the zooplankter Vorticella sp., which increased in the 25 and 75 μg L−1 treatments. After approximately 8 mo of Cu exposure, the macroinvertebrate community in the high treatment was decimated to the point that few organisms could be detected, with moderate effects in the medium treatment, and very slight effects in the low-Cu treatment. Subsequently, most taxa in the high-Cu exposure began a gradual and partial recovery. By the end of the study at 18 mo, macroinvertebrate taxa richness was similar to control richness, although overall abundances remained lower than controls. After 18 mo of copper exposure, a no-observed-effect concentration at the community level for consumers was set at 5 μg L−1 (4 μg L−1 as average effective concentration), and a lowest-observed-effect concentration at 25 μg L−1(20 μg L−1 as average effective concentration). 

Assessment of acetabular retroversion following long term review of Salter's osteotomy.

PubMed

Robb, Curtis A; Datta, Amit; Nayeemuddin, Mohammed; Bache, Christopher E

2009-01-01

Salter's innominate osteotomy may predispose to anterior over-coverage of the acetabulum. Over cover or retroversion has been demonstrated to be a cause of hip pain, impingement and subsequent osteoarthritis. We reviewed the long-term follow up of seventeen skeletally mature hips in sixteen patients who had previously undergone a Salter's osteotomy in childhood. The Salter pelvic osteotomy was performed at a mean average age of 5 years and follow up at a mean average age of 20 years. Patients were assessed by clinical examination for signs of impingement, Harris Hip Score and pelvic radiograph. Acetabular version was evaluated by the relationship between anterior and posterior walls of the acetabulum using templates applied to the pelvic radiograph as described by Hefti. The median acetabular cover averaged 17 degrees of anteversion with 2 patients (12%) demonstrating retroversion, neither of whom, had signs of impingement on examination. The mean average Harris Hip Score was 85 indicating a good outcome at long-term follow-up. We believe acetabular remodelling may occur with age after Salter's innominate osteotomy and have found good results in patients after skeletal maturation. Fears of long-term anterior over-coverage and retroversion with this operation may be unfounded.

Executive Functioning Skills in Long-Term Users of Cochlear Implants: A Case Control Study

PubMed Central

Pisoni, David B.; Henning, Shirley C.; Colson, Bethany G.

2013-01-01

Objective To investigate differences in executive functioning between deaf children with cochlear implants (CIs) and normal-hearing (NH) peers. The cognitive effects of auditory deprivation in childhood may extend beyond speech–language skills to more domain-general areas including executive functioning. Methods Executive functioning skills in a sample of 53 prelingually deaf children, adolescents, and young adults who received CIs prior to age 7 years and who had used their CIs for ≥7 years were compared with age- and nonverbal IQ-matched NH peers and with scale norms. Results Despite having above average nonverbal IQ, the CI sample scored lower than the NH sample and test norms on several measures of short-term/working memory, fluency–speed, and inhibition–concentration. Executive functioning was unrelated to most demographic and hearing history characteristics. Conclusions Prelingual deafness and long-term use of CIs was associated with increased risk of weaknesses in executive functioning. PMID:23699747

The Singer's Formant and Speaker's Ring Resonance: A Long-Term Average Spectrum Analysis

PubMed Central

Lee, Sang-Hyuk; Kwon, Hee-Jun; Choi, Hyun-Jin; Lee, Nam-Hun; Lee, Sung-Jin

2008-01-01

Objectives We previously showed that a trained tenor's voice has the conventional singer's formant at the region of 3 kHz and another energy peak at 8-9 kHz. Singers in other operatic voice ranges are assumed to have the same peak in their singing and speaking voice. However, to date, no specific measurement of this has been made. Methods Tenors, baritones, sopranos and mezzo sopranos were chosen to participate in this study of the singer's formant and the speaker's ring resonance. Untrained males (n=15) and females (n=15) were included in the control group. Each subject was asked to produce successive /a/ vowel sounds in their singing and speaking voice. For singing, the low pitch was produced in the chest register and the high notes in the head register. We collected the data on the long-term average spectra of the speaking and singing voices of the trained singers and the control groups. Results For the sounds produced from the head register, a significant energy concentration was seen in both 2.2-3.4 kHz and 7.5-8.4 kHz regions (except for the voices of the mezzo sopranos) in the trained singer group when compared to the control groups. Also, the chest register had a significant energy concentration in the 4 trained singer groups at the 2.2-3.1 kHz and 7.8-8.4 kHz. For speaking sound, all trained singers had a significant energy concentration at 2.2-5.3 kHz and sopranos had another energy concentration at 9-10 kHz. Conclusion The results of this study suggest that opera singers have more energy concentration in the singer's formant/speaker's ring region, in both singing and speaking voices. Furthermore, another region of energy concentration was identified in opera singer's singing sound and in sopranos' speaking sound at 8-9 kHz. The authors believe that these energy concentrations may contribute to the rich voice of trained singers. PMID:19434279

The effect of changes to the method of estimating the pollen count from aerobiological samples.

PubMed

Sikoparija, Branko; Pejak-Šikoparija, Tatjana; Radišić, Predrag; Smith, Matt; Soldevilla, Carmen Galán

2011-02-01

Pollen data have been recorded at Novi Sad in Serbia since 2000. The adopted method of producing pollen counts has been the use of five longitudinal transects that examine 19.64% of total sample surface. However, counting five transects is time consuming and so the main objective of this study is to investigate whether reducing the number to three or even two transects would have a significant effect on daily average and bi-hourly pollen concentrations, as well as the main characteristics of the pollen season and long-term trends. This study has shown that there is a loss of accuracy in daily average and bi-hourly pollen concentrations (an increase in % ERROR) as the sub-sampling area is reduced from five to three or two longitudinal transects. However, this loss of accuracy does not impact on the main characteristics of the season or long-term trends. As a result, this study can be used to justify changing the sub-sampling method used at Novi Sad from five to three longitudinal transects. The use of two longitudinal transects has been ruled out because, although quicker, the counts produced: (a) had the greatest amount of % ERROR, (b) altered the amount of influence of the independent variable on the dependent variable (the slope in regression analysis) and (c) the total sampled surface (7.86%) was less than the minimum requirement recommended by the European Aerobiology Society working group on Quality Control (at least 10% of total slide area).

Long-Term Time Series of Remote Sensing Observations for Development of Regulatory Water Quality Standards

NASA Technical Reports Server (NTRS)

Blonski, Slawomir; Spiering, Bruce A.; Holekamp, Kara L.

2010-01-01

Water quality standards in the U.S. consist of: designated uses (the services that a water body provides; e.g., drinking water, aquatic life, harvestable species, recreation) . criteria that define the environmental conditions that must be maintained to support the uses For estuaries and coastal waters in the Gulf of Mexico, there are no numeric (quantitative) criteria to protect designated uses from effects of nutrients. This is largely due to the absence of adequate data that would quantitatively link biological conditions to nutrient concentrations. The Gulf of Mexico Alliance, an organization fostering collaboration between the Gulf States and U.S. Federal agencies, has identified the development of the numeric nutrient criteria as a major step leading to reduction in MODIS Products Figure 6. Map of the Mobile Bay with a yellow patch indicating the Bon Secour Bay area selected in this study for averaging water clarity parameters retrieved from MODIS datasets. nutrient inputs to coastal ecosystems. Nutrient enrichment in estuaries and coastal waters can be quantified based on response variables that measure phytoplankton biomass and water clarity. Long-term, spatially and temporally resolved measurements of chlorophyll a concentration, total concentration of suspended solids, and water clarity are needed to establish reference conditions and to quantify stressor-response relationships.

Long-term outcomes of anterior spinal fusion for treating thoracic adolescent idiopathic scoliosis curves: average 15-year follow-up analysis.

PubMed

Sudo, Hideki; Ito, Manabu; Kaneda, Kiyoshi; Shono, Yasuhiro; Takahata, Masahiko; Abumi, Kuniyoshi

2013-05-01

Retrospective review. To assess the long-term outcomes of anterior spinal fusion (ASF) for treating thoracic adolescent idiopathic scoliosis (AIS). Although ASF is reported to provide good coronal and sagittal correction of the main thoracic (MT) AIS curves, the long-term outcomes of ASF is unknown. A consecutive series of 25 patients with Lenke 1 MT AIS were included. Outcome measures comprised radiographical measurements, pulmonary function, and Scoliosis Research Society outcome instrument (SRS-30) scores (preoperative SRS-30 scores were not documented). Postoperative surgical revisions and complications were recorded. Twenty-five patients were followed-up for 12 to 18 years (average, 15.2 yr). The average MT Cobb angle correction rate and the correction loss at the final follow-up were 56.7% and 9.2°, respectively. The average preoperative instrumented level of kyphosis was 8.3°, which significantly improved to 18.6° (P = 0.0003) at the final follow-up. The average percent-predicted forced vital capacity and forced expiratory volume in 1 second were significantly decreased during long-term follow-up measurements (73% and 69%; P = 0.0004 and 0.0016, respectively). However, no patient had complaints related to pulmonary function. The average total SRS-30 score was 4.0. Implant breakage was not observed. All patients, except 1 who required revision surgery, demonstrated solid fusion. Late instrumentation-related bronchial problems were observed in 1 patient who required implant removal and bronchial tube repair, 13 years after the initial surgery. Overall radiographical findings and patient outcome measures of ASF for Lenke 1 MT AIS were satisfactory at an average follow-up of 15 years. ASF provides significant sagittal correction of the main thoracic curve with long-term maintenance of sagittal profiles. Percent-predicted values of forced vital capacity and forced expiratory volume in 1 second were decreased in this cohort; however, no patient had complaints related to pulmonary function.

Surface ozone in China: present-day distribution and long-term changes

NASA Astrophysics Data System (ADS)

Xu, X.; Lin, W.; Xu, W.

2017-12-01

Reliable knowledge of spatio-temporal variations of surface ozone is highly needed to assess the impacts of ozone on human health, ecosystem and climate. Although regional distributions and trends of surface ozone in European and North American countries have been well characterized, little is known about the variability of surface ozone in many other countries, including China, where emissions of ozone precursors have been changing rapidly in recent decades. Here we present the first comprehensive description of present-day (2013-2017) distribution and long-term changes of surface ozone in mainland China. Recent ozone measurements from China's air quality monitoring network (AQMN) are analyzed to show present-day distributions of a few ozone exposure metrics for urban environment. Long-term measurements of ozone at six background sites, a rural site and an urban are used to study the trends of ozone in background, rural and urban air, respectively. The average levels of ozone at the AQMN sites (mainly urban) are close to those found at many European and North American sites. However, ozone at most of the sites shows very large diurnal and seasonal variations so that ozone nonattainment can occur in many cities, particularly those in the North China Plain (NCP), the south of Northeast China (NEC), the Yangtze River Delta (YRD), the Pearl River Delta (PRD), and the Sichuan Basin-Chongqing region (SCB). In all these regions, particularly in the NCP, the maximum daily 8-h average (MDA8) ozone concentration can significantly exceed the national limit (75 ppb). High annual sum of ozone means over 35 ppb (SOMO35) exist mainly in the NCP, NEC and YRD, with regional averages over 4000 ppb·d. Surface ozone has significantly increased at Waliguan (a baseline site in western China) and Shangdianzi (a background site in the NCP), and decreased in winter and spring at Longfengshan (a background site in Northeast China). No clear trend can be derived from long-term measurements of ozone at other sites. Further attention should be paid to future changes of ozone in populated regions of China. Actions are urgently needed to control ozone pollution in the NCP and YRD.

Long open-path TDL based system for monitoring background concentration for deployment at Jungfraujoch High Altitude Research Station- Switzerland

NASA Astrophysics Data System (ADS)

Simeonov, Valentin; van den Bergh, Hubert; Parlange, Marc

2010-05-01

A new, long open-path instrument for monitoring of path-averaged methane and water vapor concentrations will be presented. The instrument is built on the monostatic scheme (transceiver - distant retroreflector). A VCSEL tunable diode laser (TDL) with a central wavelength of 1654 nm is used as a light source. A specially designed, single-cell, hollow-cube retroreflector with 150 mm aperture will be installed at 1200 m from the transceiver in the final deployment at Jungfraujjoch and 100 mm retroreflectors will be used in the other applications. The receiver is built around a 20 cm Newtonian telescope. To avoid distortions in the shape of a methane line, caused by atmospheric turbulences, the line is scanned within 1 µs. Fast InGaAs photodiodes and 200 MHz are used to achieve this scanning rate. The expected concentration resolution for the above mentioned path lengths is of the order of 2 ppb. The instrument is developed at the Swiss Federal Institute of Technology - Lausanne (EPFL) Switzerland and will be used within the GAW+ CH program for long-term monitoring of background methane concentration in the Swiss Alps. After completing the initial tests at EPFL the instrument will be installed in 2012 at the High Altitude Research Station Jungfraujoch (HARSJ) located at 3580 m ASL. The HARSJ is one of the 24 global GAW stations and carries on continuous observations of a number of trace gasses, including methane. One of the goals of the project is to compare path-averaged to ongoing point measurements of methane in order to identify possible influence of the station. Future deployments of a copy of the instrument include the Colombian part of Amazonia and Siberian wetlands.

75 FR 66271 - Assessment Dividends, Assessment Rates and Designated Reserve Ratio

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-27

... has recovered to pre-crisis levels, and the long term, when the reserve ratio is sufficiently large... detail below, concludes that a moderate, long-term average industry assessment rate, combined with an... and earnings of IDIs. Long Term To increase the probability that the fund reserve ratio will reach a...

Worker exposure to methanol vapors during cleaning of semiconductor wafers in a manufacturing setting.

PubMed

Gaffney, Shannon; Moody, Emily; McKinley, Meg; Knutsen, Jeffrey; Madl, Amy; Paustenbach, Dennis

2008-05-01

An exposure simulation was conducted to characterize methanol exposure of workers who cleaned wafers in quality control departments within the semiconductor industry. Short-term (15 min) and long-term (2-4 hr) personal and area samples (at distances of 1 m and 3-6 m from the source) were collected during the 2-day simulation. On the first day, 45 mL of methanol were used per hour by a single worker washing wafers in a 102 m(3) room with a ventilation rate of about 10 air changes per hour (ACH). Virtually all methanol volatilized. To assess exposures under conditions associated with higher productivity, on the second day, two workers cleaned wafers simultaneously, together using methanol at over twice the rate of the first day (95 mL/hr). On this day, the ventilation rate was halved (5 ACH). Personal concentrations on the first day averaged 60 ppm (SD = 46 ppm) and ranged from 10-140 ppm. On the second day, personal concentrations for both workers averaged 118 ppm (SD = 50 ppm; range: 64-270 ppm). Area concentrations measured on the first day at 1 m from the source and throughout the balance of the room averaged 29 ppm (SD = 19 ppm; range: 4-83 ppm) and 18 ppm (SD = 12 ppm; range: 3-42 ppm), respectively. As expected, area concentrations measured on the second day were higher than the first and averaged 73 ppm (SD = 25 ppm; range: 27-140 ppm) at 1 meter and 48 ppm (SD = 13 ppm; range: 21-67 ppm) throughout the balance of the room. The results of this simulation suggest that the use of methanol to clean semiconductor wafers without the use of local exhaust ventilation and with relatively low room ventilation rates is unlikely to result in worker exposures exceeding the current ACGIH(R) threshold limit value of 200 ppm. This study also confirmed prior studies suggesting that when a relatively volatile chemical is located within arm's length (near field), breathing zone concentrations will be about two- to threefold greater than the room concentration when the air exchange rate is 5-10 ACH.

Cognitive correlates of long-term cannabis use in Costa Rican men.

PubMed

Fletcher, J M; Page, J B; Francis, D J; Copeland, K; Naus, M J; Davis, C M; Morris, R; Krauskopf, D; Satz, P

1996-11-01

Cognitive correlates of long-term cannabis use have been elusive. We tested the hypothesis that long-term cannabis use is associated with deficits in short term memory, working memory, and attention in a literate, westernized culture (Costa Rica) in which the effects of cannabis use can be isolated. Two cohorts of long-term cannabis users and nonusers were studied. Within each cohort, users and nonusers were comparable in age and socioeconomic status. Polydrug users and users who tested positive for the use of cannabis at the time of cognitive assessment after a 72-hour abstention period were excluded. The older cohort (whose age was approximately 45 years) had consumed cannabis for an average of 34 years, and comprised 17 users and 30 nonusers, who had been recruited in San José, Costa Rica, and had been observed since 1973. The younger cohort (whose age was approximately 28 years) had consumed cannabis for an average of 8 years, and comprised 37 users and 49 nonusers. Short-term memory, working memory, and attentional skills were measured in each subject. Older long-term users performed worse than older nonusers on 2 short-term memory tests involving learning lists of words. In addition, older long-term users performed worse than older nonusers on selective and divided attention tasks associated with working memory. No notable differences were apparent between younger users and nonusers. Long-term cannabis use was associated with disruption of short-term memory, working memory, and attentional skills in older long-term cannabis users.

Estimation of spatial patterns of urban air pollution over a 4-week period from repeated 5-min measurements

NASA Astrophysics Data System (ADS)

Gillespie, Jonathan; Masey, Nicola; Heal, Mathew R.; Hamilton, Scott; Beverland, Iain J.

2017-02-01

Determination of intra-urban spatial variations in air pollutant concentrations for exposure assessment requires substantial time and monitoring equipment. The objective of this study was to establish if short-duration measurements of air pollutants can be used to estimate longer-term pollutant concentrations. We compared 5-min measurements of black carbon (BC) and particle number (PN) concentrations made once per week on 5 occasions, with 4 consecutive 1-week average nitrogen dioxide (NO2) concentrations at 18 locations at a range of distances from busy roads in Glasgow, UK. 5-min BC and PN measurements (averaged over the two 5-min periods at the start and end of a week) explained 40-80%, and 7-64% respectively, of spatial variation in the intervening 1-week NO2 concentrations for individual weeks. Adjustment for variations in background concentrations increased the percentage of explained variation in the bivariate relationship between the full set of NO2 and BC measurements over the 4-week period from 28% to 50% prior to averaging of repeat measurements. The averages of five 5-min BC and PN measurements made over 5 weeks explained 75% and 33% respectively of the variation in average 1-week NO2 concentrations over the same period. The relatively high explained variation observed between BC and NO2 measured on different time scales suggests that, with appropriate steps to correct or average out temporal variations, repeated short-term measurements can be used to provide useful information on longer-term spatial patterns for these traffic-related pollutants.

Association between air pollution and coronary artery calcification within six metropolitan areas in the USA (the Multi-Ethnic Study of Atherosclerosis and Air Pollution): a longitudinal cohort study.

PubMed

Kaufman, Joel D; Adar, Sara D; Barr, R Graham; Budoff, Matthew; Burke, Gregory L; Curl, Cynthia L; Daviglus, Martha L; Diez Roux, Ana V; Gassett, Amanda J; Jacobs, David R; Kronmal, Richard; Larson, Timothy V; Navas-Acien, Ana; Olives, Casey; Sampson, Paul D; Sheppard, Lianne; Siscovick, David S; Stein, James H; Szpiro, Adam A; Watson, Karol E

2016-08-13

Long-term exposure to fine particulate matter less than 2.5 μm in diameter (PM2.5) and traffic-related air pollutant concentrations are associated with cardiovascular risk. The disease process underlying these associations remains uncertain. We aim to assess association between long-term exposure to ambient air pollution and progression of coronary artery calcium and common carotid artery intima-media thickness. In this prospective 10-year cohort study, we repeatedly measured coronary artery calcium by CT in 6795 participants aged 45-84 years enrolled in the Multi-Ethnic Study of Atherosclerosis and Air Pollution (MESA Air) in six metropolitan areas in the USA. Repeated scans were done for nearly all participants between 2002 and 2005, for a subset of participants between 2005 and 2007, and for half of all participants between 2010 and 2012. Common carotid artery intima-media thickness was measured by ultrasound in all participants at baseline and in 2010-12 for 3459 participants. Residence-specific spatio-temporal pollution concentration models, incorporating community-specific measurements, agency monitoring data, and geographical predictors, estimated concentrations of PM2.5 and nitrogen oxides (NOX) between 1999 and 2012. The primary aim was to examine the association between both progression of coronary artery calcium and mean carotid artery intima-media thickness and long-term exposure to ambient air pollutant concentrations (PM2.5, NOX, and black carbon) between examinations and within the six metropolitan areas, adjusting for baseline age, sex, ethnicity, socioeconomic characteristics, cardiovascular risk factors, site, and CT scanner technology. In this population, coronary calcium increased on average by 24 Agatston units per year (SD 58), and intima-media thickness by 12 μm per year (10), before adjusting for risk factors or air pollutant exposures. Participant-specific pollutant concentrations averaged over the years 2000-10 ranged from 9.2-22.6 μg PM2.5/m(3) and 7.2-139.2 parts per billion (ppb) NOX. For each 5 μg PM2.5/m(3) increase, coronary calcium progressed by 4.1 Agatston units per year (95% CI 1.4-6.8) and for each 40 ppb NOX coronary calcium progressed by 4.8 Agatston units per year (0.9-8.7). Pollutant exposures were not associated with intima-media thickness change. The estimate for the effect of a 5 μg/m(3) higher long-term exposure to PM2.5 in intima-media thickness was -0.9 μm per year (95% CI -3.0 to 1.3). For 40 ppb higher NOX, the estimate was 0.2 μm per year (-1.9 to 2.4). Increased concentrations of PM2.5 and traffic-related air pollution within metropolitan areas, in ranges commonly encountered worldwide, are associated with progression in coronary calcification, consistent with acceleration of atherosclerosis. This study supports the case for global efforts of pollution reduction in prevention of cardiovascular diseases. US Environmental Protection Agency and US National Institutes of Health. Copyright © 2016 Elsevier Ltd. All rights reserved.

Estimating Air-Manganese Exposures in Two Ohio Towns ...

EPA Pesticide Factsheets

Manganese (Mn), a nutrient required for normal metabolic function, is also a persistent air pollutant and a known neurotoxin at high concentrations. Elevated exposures can result in a number of motor and cognitive deficits. Quantifying chronic personal exposures in residential populations studied by environmental epidemiologists can be time-consuming and expensive. We developed an approach for quantifying chronic exposures for two towns (Marietta and East Liverpool, Ohio) with elevated air Mn concentrations (air-Mn) related to ambient emissions from industrial processes. This was accomplished through the use of measured and modeled data in the communities studied. A novel approach was developed because one of the facilities lacked emissions data for the purposes of modeling. A unit emission rate was assumed over the surface area of both source facilities, and offsite concentrations at receptor residences and air monitoring sites were estimated with the American Meteorological Society/Environmental Protection Agency Regulatory Model (AERMOD). Ratios of all modeled receptor points were created, and a long-running air monitor was identified as a reference location. All ratios were normalized to the reference location. Long-term averages at all residential receptor points were calculated using modeled ratios and data from the reference monitoring location. Modeled five-year average air-Mn exposures ranged from 0.03-1.61 µg/m3 in Marietta and 0.01-6.32 µg/m3 in E

Mountain erosion over decades and millennia: New insights from sediment yields and cosmogenic nuclides

NASA Astrophysics Data System (ADS)

Callahan, R. P.; Riebe, C. S.; Ferrier, K.

2017-12-01

For more than two decades, cosmogenic nuclides have been used to quantify catchment-wide erosion rates averaged over tens of thousands of years. These rates have been used as baselines for comparison with sediment yields averaged over decades, leading to insights on how human activities such as deforestation and agriculture have influenced the production and delivery of sediment to streams and oceans. Here we present new data from the southern Sierra Nevada, California, where sediment yields have been measured over the last ten years using sediment trapping and gauging methods. Cosmogenic nuclides measured in stream sediment reveal erosion rates that are between 13 and 400 (average = 94) times faster than erosion rates inferred from annual accumulations in sediment traps. We show that the discrepancy can be explained by extremely low sediment trapping efficiency, which leads to bias in the short-term rates due to incomplete capture of suspended sediment. Thus the short-term rates roughly agree with the long-term rates, despite intensive timber harvesting in the study catchments over the last century. This differs from results obtained in similar forested granitic catchments of Idaho, where long-term rates are more than ten times greater than short-term rates because large, rare events do not contribute to the short-term averages. Our analysis of a global database indicates that both the magnitude and sign of differences between short- and long-term average erosion rates are difficult to predict, even when the history of land use in known.

Long open-path instrument for simultaneously monitoring of methane, CO2 and water vapor

NASA Astrophysics Data System (ADS)

Simeonov, Valentin; Parlange, Marc

2013-04-01

A new, long open-path instrument for monitoring of path-averaged methane, CO2 and water vapor concentrations will be presented. The instrument is built on the monostatic scheme (transceiver -distant retroreflector). A VCSEL with a central wavelength of 1654 nm is used as a light source. The receiver is built around a 20 cm Newtonian telescope. The design optical path length is 2000 m but can be further extended. To avoid distortions in the shape of the spectral lines caused by atmospheric turbulences they are scanned within 1 µs. The expected concentration resolution for the above mentioned path length is of the order of 2 ppb for methane, 100 ppb for CO2 and 100 ppm for water vapor. The instrument is developed at the Swiss Federal Institute of Technology - Lausanne (EPFL) Switzerland and will be used within the GAW+ CH program for long-term monitoring of background methane and CO2 concentrations in the Swiss Alps. The initial calibration validation tests at EPFL were completed in December 2012 and the instrument will be installed at the beginning of 2013 at the High Altitude Research Station Jungfraujoch (HARSJ). The HARSJ is located at 3580 m ASL and is one of the 24 global GAW stations. One of the goals of the project is to compare path-averaged to the ongoing point measurements of methane in order to identify possible influence of the station. Future deployments of a copy of the instrument include the Canadian arctic and Siberian wetlands. The instrument can be used for ground truthing of satellite observation as well.

76 FR 48130 - Certain Pasta From Italy: Preliminary Results of the 14th (2009) Countervailing Duty...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-08

... rate versus variable interest rate), the maturity of the loan (e.g., short-term versus long-term), and... were received. Benchmarks for Long-Term Loans and Discount Rates Pursuant to 19 CFR 351.505(a), the... using the national average cost of long-term, fixed-rate loans pursuant to 19 CFR 351.524(d)(3)(B...

Post-mortem quetiapine concentrations in hair segments of psychiatric patients - Correlation between hair concentration, dose and concentration in blood.

PubMed

Günther, Kamilla Nyborg; Johansen, Sys Stybe; Nielsen, Marie Katrine Klose; Wicktor, Petra; Banner, Jytte; Linnet, Kristian

2018-04-01

Drug analysis in hair is useful when seeking to establish drug intake over a period of months to years. Segmental hair analysis can also document whether psychiatric patients are receiving a stable intake of antipsychotics. This study describes segmental analysis of the antipsychotic drug quetiapine in post-mortem hair samples from long-term quetiapine users by ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) analysis. The aim was to obtain more knowledge on quetiapine concentrations in hair and to relate the concentration in hair to the administered dose and the post-mortem concentration in femoral blood. We analyzed hair samples from 22 deceased quetiapine-treated individuals, who were divided into two groups: natural hair colour and dyed/bleached hair. Two to six 1cm long segments were analyzed per individual, depending on the length of the hair, with 6cm corresponding to the last six months before death. The average daily quetiapine dose and average concentration in hair for the last six months prior to death were examined for potential correlation. Estimated doses ranged from 45 to 1040mg quetiapine daily over the period, and the average concentration in hair ranged from 0.18 to 13ng/mg. A significant positive correlation was observed between estimated daily dosage of quetiapine and average concentration in hair for individuals with natural hair colour (p=0.00005), but statistical significance was not reached for individuals with dyed/bleached hair (p=0.31). The individual coefficient of variation (CV) of the quetiapine concentrations between segments ranged from 3 to 34% for individuals with natural hair colour and 22-62% for individuals with dyed/bleached hair. Dose-adjusted concentrations in hair were significantly lower in females with dyed/bleached hair than in individuals with natural hair colour. The quetiapine concentrations in post-mortem femoral blood and in the proximal hair segment, segment 1 (S1), representing the last month before death were also investigated for correlation. A significant positive correlation was observed between quetiapine concentrations in blood at the time of death and concentrations in S1 for individuals with natural hair colour (p=0.003) but not for individuals with dyed/bleached hair (p=0.31). The blood concentrations of quetiapine ranged from 0.006 to 1.9mg/kg, and the quetiapine concentrations in S1 ranged from 0.22 to 24ng/mg. The results of this study suggest a positive correlation of quetiapine between both concentrations in hair and doses, and between proximal hair (S1) and blood concentrations, when conditions such as hair treatments are taken into consideration. Copyright © 2018 Elsevier B.V. All rights reserved.

Monitoring and assessment of radionuclide discharges from Temelín Nuclear Power Plant into the Vltava River (Czech Republic).

PubMed

Hanslík, Eduard; Ivanovová, Diana; Juranová, Eva; Simonek, Pavel; Jedináková-Krízová, Vĕra

2009-02-01

The paper summarizes impacts of the Temelín Nuclear Power Plant (NPP) on the Vltava and Labe River basins. The study is based on the results of long-term monitoring carried out before the plant operation (1989-2000), and subsequently during the plant operation (2001-2005). In the first period, the main objective was to determine background radionuclide levels remaining in the environment after global fallout and due to the Chernobyl accident. A decrease in the concentrations of (90)Sr, (134)Cs and (137)Cs, which was observed before the plant operation, continued also during the subsequent period. Apart from tritium, the results of the observation did not indicate any impacts of the plant on the concentrations of activation and fission products in the hydrosphere. The annual average tritium concentrations in the Vltava River were in agreement with predicted values. The maximum annual average tritium concentration (13.5 Bq L(-1)) was observed in 2004 downstream from the wastewater discharge in the Vltava River at Solenice. Estimated radiation doses for adults due to intakes of river water as drinking water contaminated by tritium are below 0.1 microSv y(-1).

Long-Term Retrospective Clinical and Radiographic Follow-up of 205 Brånemark System Mk III TiUnite Implants Submitted to Either Immediate or Delayed Loading.

PubMed

Imburgia, Mario; Del Fabbro, Massimo

2015-10-01

Studies are needed to evaluate long-term performance of immediately loaded implants with moderately rough surface. This retrospective study evaluated long-term survival and periimplant soft and hard tissue conditions in patients treated with TiUnite implants. Forty-one consecutive patients (mean age, 52.6 years) received 205 Brånemark System Mk III TiUnite implants (145 maxillary, 60 mandibular). The indication was single tooth (n = 7 implants), partial (n = 94), or full arches (n = 104). One hundred thirteen implants were immediately loaded. Cumulative survival rate (CSR) of implants was assessed. Long-term marginal bone remodeling, probing pocket depth (PPD), and periimplant mucosa conditions were assessed. Follow-up averaged 8.8 years (range, 6.6-10.6 years). Eight implants in 5 patients failed. CSR was 96.1% (implant basis) and 87.8% (patient basis) up to 10 years. At the longest follow-up, bone loss averaged 0.43 ± 1.15 mm (n = 173), PPD averaged 3.64 ± 0.74 mm, and periimplant mucosa was healthy in 74.6% of cases. Furthermore, 50.3% and 35.5% of implants scored negative for plaque and bleeding, respectively. No significant difference in CSR and hard and soft tissue conditions was found in the long term between immediately and delayed loaded implants. Implants with TiUnite surface demonstrated excellent long-term survival, marginal bone response, and soft tissue conditions, despite a nonoptimal level of oral hygiene.

Effects of Agricultural Land-Use Changes and Rainfall on Ground-Water Recharge in Central and West Maui, Hawai`i, 1926-2004

USGS Publications Warehouse

Engott, John A.; Vana, Thomas T.

2007-01-01

Concern surrounding declines in ground-water levels and an increase in the chloride concentration of water pumped from wells in the Iao aquifer system on the Island of Maui has prompted an investigation into the long-term sustainability of current (2006) and future ground-water withdrawals. As part of this investigation, a water budget for central and west Maui was calculated from which (1) ground-water recharge was estimated for the period 1926-2004 and (2) the effects of agricultural land-use changes and drought were analyzed. Estimated mean ground-water recharge decreased 44 percent from 1979 to 2004 in central and west Maui. Reduction in agricultural irrigation, resulting from more efficient irrigation methods and a reduction in the acreage used for agriculture, is largely responsible for the declining recharge. Recently, periods of lower-than-average rainfall have further reduced recharge. During the period 1926-79, ground-water recharge averaged 693 Mgal/d, irrigation averaged 437 Mgal/d, and rainfall averaged 897 Mgal/d. During the period 2000-04, ground-water recharge averaged 391 Mgal/d, irrigation averaged 237 Mgal/d, and rainfall averaged 796 Mgal/d. Simulations of hypothetical future conditions indicate that a cessation of agriculture in central and west Maui would reduce mean ground-water recharge by 18 percent in comparison with current conditions, assuming that current climatic conditions are the same as the long-term-average conditions during the period 1926-2004. A period of drought identical to that of 1998-2002 would reduce mean recharge by 27 percent. Mean recharge would decrease by 46 percent if this drought were to occur after a cessation of agriculture in central and western Maui. Whereas droughts are transient phenomena, a reduction in agricultural irrigation is likely a permanent condition.

Prospective memory deficits in illicit polydrug users are associated with the average long-term typical dose of ecstasy typically consumed in a single session.

PubMed

Gallagher, Denis T; Hadjiefthyvoulou, Florentia; Fisk, John E; Montgomery, Catharine; Robinson, Sarita J; Judge, Jeannie

2014-01-01

Neuroimaging evidence suggests that ecstasy-related reductions in SERT densities relate more closely to the number of tablets typically consumed per session rather than estimated total lifetime use. To better understand the basis of drug related deficits in prospective memory (p.m.) we explored the association between p.m. and average long-term typical dose and long-term frequency of use. Study 1: Sixty-five ecstasy/polydrug users and 85 nonecstasy users completed an event-based, a short-term and a long-term time-based p.m. task. Study 2: Study 1 data were merged with outcomes on the same p.m. measures from a previous study creating a combined sample of 103 ecstasy/polydrug users, 38 cannabis-only users, and 65 nonusers of illicit drugs. Study 1: Ecstasy/polydrug users had significant impairments on all p.m. outcomes compared with nonecstasy users. Study 2: Ecstasy/polydrug users were impaired in event-based p.m. compared with both other groups and in long-term time-based p.m. compared with nonillicit drug users. Both drug using groups did worse on the short-term time-based p.m. task compared with nonusers. Higher long-term average typical dose of ecstasy was associated with poorer performance on the event and short-term time-based p.m. tasks and accounted for unique variance in the two p.m. measures over and above the variance associated with cannabis and cocaine use. The typical ecstasy dose consumed in a single session is an important predictor of p.m. impairments with higher doses reflecting increasing tolerance giving rise to greater p.m. impairment.

Historical Prediction Modeling Approach for Estimating Long-Term Concentrations of PM2.5 in Cohort Studies before the 1999 Implementation of Widespread Monitoring

PubMed Central

Kim, Sun-Young; Olives, Casey; Sheppard, Lianne; Sampson, Paul D.; Larson, Timothy V.; Keller, Joshua P.; Kaufman, Joel D.

2016-01-01

Introduction: Recent cohort studies have used exposure prediction models to estimate the association between long-term residential concentrations of fine particulate matter (PM2.5) and health. Because these prediction models rely on PM2.5 monitoring data, predictions for times before extensive spatial monitoring present a challenge to understanding long-term exposure effects. The U.S. Environmental Protection Agency (EPA) Federal Reference Method (FRM) network for PM2.5 was established in 1999. Objectives: We evaluated a novel statistical approach to produce high-quality exposure predictions from 1980 through 2010 in the continental United States for epidemiological applications. Methods: We developed spatio-temporal prediction models using geographic predictors and annual average PM2.5 data from 1999 through 2010 from the FRM and the Interagency Monitoring of Protected Visual Environments (IMPROVE) networks. Temporal trends before 1999 were estimated by using a) extrapolation based on PM2.5 data in FRM/IMPROVE, b) PM2.5 sulfate data in the Clean Air Status and Trends Network, and c) visibility data across the Weather Bureau Army Navy network. We validated the models using PM2.5 data collected before 1999 from IMPROVE, California Air Resources Board dichotomous sampler monitoring (CARB dichot), the Children’s Health Study (CHS), and the Inhalable Particulate Network (IPN). Results: In our validation using pre-1999 data, the prediction model performed well across three trend estimation approaches when validated using IMPROVE and CHS data (R2 = 0.84–0.91) with lower R2 values in early years. Model performance using CARB dichot and IPN data was worse (R2 = 0.00–0.85) most likely because of fewer monitoring sites and inconsistent sampling methods. Conclusions: Our prediction modeling approach will allow health effects estimation associated with long-term exposures to PM2.5 over extended time periods ≤ 30 years. Citation: Kim SY, Olives C, Sheppard L, Sampson PD, Larson TV, Keller JP, Kaufman JD. 2017. Historical prediction modeling approach for estimating long-term concentrations of PM2.5 in cohort studies before the 1999 implementation of widespread monitoring. Environ Health Perspect 125:38–46; http://dx.doi.org/10.1289/EHP131 PMID:27340825

Long-term average spectrum in screening of voice quality in speech: untrained male university students.

PubMed

Leino, Timo

2009-11-01

Voice quality has mainly been studied in trained speakers, singers, and dysphonic patients. Few studies have concerned ordinary untrained university students' voices. In light of earlier studies of professional voice users, it was hypothesized that good, poor, and intermediate voices would be distinguishable on the basis of long-term average spectrum characteristics. In the present study, voice quality of 50 Finnish vocally untrained male university students was studied perceptually and using long-term average spectrum analysis of text reading samples of one minute duration. Equivalent sound level (Leq) of text reading was also measured. According to the results, the good and ordinary voices differed from the poor ones in their relatively higher sound level in the frequency range of 1-3 kHz and a prominent peak at 3-4 kHz. Good voices, however, did not differ from the ordinary voices in terms of the characteristics of the long-term average spectrum (LTAS). The strength of the peak at 3-4 kHz and the voice-quality scores correlated weakly but significantly. Voice quality and alpha ratio (level difference above and below 1 kHz) correlated likewise. Leq was significantly higher in the students with good and ordinary voices than in those with poor voices. The connections between Leq, voice quality, and the formation of the peak at 3-4 kHz warrant further studies.

Long-term Trend of Satellite-observed Chlorophyll-a Concentration Variations in the East/Japan Sea

NASA Astrophysics Data System (ADS)

Park, J. E.; PARK, K. A.

2016-02-01

Long-term time-series of satellite ocean color data enable us to analyze the effects of climate change on ocean ecosystem through chlorophyll-a concentration as a proxy for phytoplankton biomass. In this study, we constructed a 17 year-long time-series dataset (1998-2014) of chlorophyll-a concentration by combining SeaWiFS (Obrview-2, 1997-2010) and MODIS (Aqua, 2002-present) data in the East Sea (Japan Sea). Several types of errors such as anonymously high values (a speckle error), stripe-like patterns, discrepancy originating from time gap between the two satellites were eliminated to enhance the accuracy of chlorophyll-a concentration data. The composited chlorophyll-a concentration maps, passing through the post-processing of the speckle errors, were improved significantly, by 14% of abnormal variability in maximum. Using the database, we investigated spatial and temporal variability of chlorophyll-a concentration in the East Sea. Spatial distribution of long-term trend of chlorophyll-a concentration indicated obvious distinction between northern and southern regions of the subpolar front. It revealed predominant seasonal variabilities as well as long-term changes in the timings of spring bloom. This study addresses the important role of local climate change on fast changing ecosystem of the East Sea as one of miniature oceans.

Comparison of Short- and Long-term Hearing Outcomes of Successful Inlay Cartilage Tympanoplasty Between Small and Large Eardrum Perforations.

PubMed

Wu, Pei-Wen; Wang, Wen-Hung; Huang, Chi-Che; Lee, Ta-Jen; Huang, Chien-Chia

2015-12-01

To compare the short- and long-term hearing outcomes after successful inlay cartilage tympanoplasty between patients with small (≤25%) and large (≥50%) eardrums perforations. This is a retrospective case series study conducted in a tertiary referral center. Twenty-five patients who underwent 27 procedures were enrolled. Their mean age was 60.26 years (range, 42 to 76 years). The mean follow-up time was 18.86 months (range, 12.30 to 35.83 months). The preoperative, initial postoperative, and long-term hearing results in patients with total repair of the eardrum were analyzed. In the small size group, the average (±standard deviation) air-bone gap (ABG) closure was 1.08±7.53 dB in the short-term and 2.33±11.56 dB in the long-term hearing examinations. There was no difference between short- and long-term ABG closure (P=0.689). In the large size group, the average ABG closure was 9.77±9.40 dB in the short-term and 16.25±6.01 dB in the long-term hearing examinations. There was a significant difference between short- and long-term ABG closure (P=0.029). Patients with large perforations have continuous hearing improvement and ABG closure for more than one year. In contrast, the short- and long-term postoperative ABGs are almost the same in patients with small perforations. More long-term postoperative follow-up of hearing results is necessary for large perforations.

Blending Multiple Nitrogen Dioxide Data Sources for Neighborhood Estimates of Long-Term Exposure for Health Research.

PubMed

Hanigan, Ivan C; Williamson, Grant J; Knibbs, Luke D; Horsley, Joshua; Rolfe, Margaret I; Cope, Martin; Barnett, Adrian G; Cowie, Christine T; Heyworth, Jane S; Serre, Marc L; Jalaludin, Bin; Morgan, Geoffrey G

2017-11-07

Exposure to traffic related nitrogen dioxide (NO 2 ) air pollution is associated with adverse health outcomes. Average pollutant concentrations for fixed monitoring sites are often used to estimate exposures for health studies, however these can be imprecise due to difficulty and cost of spatial modeling at the resolution of neighborhoods (e.g., a scale of tens of meters) rather than at a coarse scale (around several kilometers). The objective of this study was to derive improved estimates of neighborhood NO 2 concentrations by blending measurements with modeled predictions in Sydney, Australia (a low pollution environment). We implemented the Bayesian maximum entropy approach to blend data with uncertainty defined using informative priors. We compiled NO 2 data from fixed-site monitors, chemical transport models, and satellite-based land use regression models to estimate neighborhood annual average NO 2 . The spatial model produced a posterior probability density function of estimated annual average concentrations that spanned an order of magnitude from 3 to 35 ppb. Validation using independent data showed improvement, with root mean squared error improvement of 6% compared with the land use regression model and 16% over the chemical transport model. These estimates will be used in studies of health effects and should minimize misclassification bias.

Climate-tree growth models in relation to long-term growth trends of white oak in Pennsylvania

Treesearch

D. D. Davis; R. P. Long

2003-01-01

We examined long-term growth trends of white oak by comparing tree-ring chronologies developed from an old-growth stand, where the average tree age was 222 years, with a second-growth stand where average tree age was 78 years. Evaluation of basal area growth trends suggested that an anomalous decrease in basal area increment trend occurred in both stands during the...

Plasma Aluminum Concentrations in Pediatric Patients Receiving Long-Term Parenteral Nutrition.

PubMed

Courtney-Martin, Glenda; Kosar, Christina; Campbell, Alison; Avitzur, Yaron; Wales, Paul W; Steinberg, Karen; Harrison, Debra; Chambers, Kathryn

2015-07-01

Patients receiving long-term parenteral nutrition (PN) are at increased risk of aluminium (Al) toxicity because of bypass of the gastrointestinal tract during PN infusion. Complications of Al toxicity include metabolic bone disease (MBD), Al-associated encephalopathy in adults, and impaired neurological development in preterm infants. Unlike the United States, there are no regulations regarding Al content of large- and small-volume parenterals in Canada. We, therefore, aimed to present our data on plasma Al concentration and Al intake from our cohort of pediatric patients receiving long-term PN. Plasma Al concentration was retrospectively gathered from the patient charts of all 27 patients with intestinal failure (IF) receiving long-term PN at The Hospital for Sick Children, Toronto, Canada, and compared with age- and sex-matched controls recruited for comparison. In addition, Al concentration was measured in PN samples collected from 10 randomly selected patients with IF and used to determine their Al intake. The plasma Al concentration of patients with IF receiving long-term PN was significantly higher than that of control participants (1195 ± 710 vs 142 ± 63 nmol/L; P < .0001). In the subgroup of 10 patients for whom Al intake from their PN solution was determined, mean ± SD Al intake from PN was 15.4 ± 15 µg/kg, 3 times the Food and Drug Administration upper recommended intake level, and Al intake was significantly related to plasma Al concentration (P = .02, r (2) = 0.52). Pediatric patients receiving long-term PN for IF in Canada are at risk for Al toxicity. © 2014 American Society for Parenteral and Enteral Nutrition.

Nitrogen dioxide exposures inside ice skating rinks.

PubMed Central

Brauer, M; Spengler, J D

1994-01-01

OBJECTIVES. The common operation of fuel-powered resurfacing equipment in enclosed ice skating rinks has the potential for producing high concentrations of carbon monoxide and nitrogen dioxide. Exposures to these gaseous combustion products may adversely affect the health of those inside the rink. Little information is available on pollutant concentrations under normal operating conditions. METHODS. One-week average nitrogen dioxide concentrations in 70 northeastern US rinks were measured with passive samplers during normal winter season conditions. RESULTS. The median nitrogen dioxide level inside rinks was 180 ppb, more than 10 times higher than the median outdoor concentration. One-week average nitrogen dioxide concentrations above 1000 ppb were measured in 10% of the rinks. CONCLUSIONS. Considering that short-term peak concentrations were likely to have reached two to five times the measured 1-week averages, our results suggest that nitrogen dioxide levels were well above short-term air quality guidelines and constitute a public health concern of considerable magnitude. PMID:8129060

A coupled system of half-nitritation and ANAMMOX for mature landfill leachate nitrogen removal.

PubMed

Li, Yun; Li, Jun; Zhao, Baihang; Wang, Xiujie; Zhang, Yanzhuo; Wei, Jia; Bian, Wei

2017-09-01

A coupled system of membrane bioreactor-nitritation (MBR-nitritation) and up-flow anaerobic sludge blanket-anaerobic ammonium oxidation (UASB-ANAMMOX) was employed to treat mature landfill leachate containing high ammonia nitrogen and low C/N. MBR-nitritation was successfully realized for undiluted mature landfill leachate with initial concentrations of 900-1500 mg/L [Formula: see text] and 2000-4000 mg/L chemical oxygen demand. The effluent [Formula: see text] concentration and the [Formula: see text] accumulation efficiency were 889 mg/L and 97% at 125 d, respectively. Half-nitritation was quickly realized by adjustment of hydraulic retention time and dissolved oxygen (DO), and a low DO control strategy could allow long-term stable operation. The UASB-ANAMMOX system showed high effective nitrogen removal at a low concentration of mature landfill leachate. The nitrogen removal efficiency was inhibited at excessive influent substrate concentration and the nitrogen removal efficiency of the system decreased as the concentration of mature landfill leachate increased. The MBR-nitritation and UASB-ANAMMOX processes were coupled for mature landfill leachate treatment and together resulted in high effective nitrogen removal. The effluent average total nitrogen concentration and removal efficiency values were 176 mg/L and 83%, respectively. However, the average nitrogen removal load decreased from 2.16 to 0.77 g/(L d) at higher concentrations of mature landfill leachate.

Trends in nitrogen concentration and nitrogen loads entering the South Shore Estuary Reserve from streams and ground-water discharge in Nassau and Suffolk counties, Long Island, New York, 1952–97

USGS Publications Warehouse

Monti, Jack; Scorca, Michael P.

2003-01-01

The 13 major south-shore streams in Nassau and Suffolk Counties, Long Island, New York with adequate long-term (1971-97) water-quality records, and 192 south-shore wells with sufficient water-quality data, were selected for analysis of geographic, seasonal, and long-term trends in nitrogen concentration. Annual total nitrogen loads transported to the South Shore Estuary Reserve (SSER) from 11 of these streams were calculated using long-term discharge records. Nitrogen loads from shallow and deep ground water also were calculated using simulated ground-water discharge of 1968-83 hydrologic conditions.Long-term declines in stream discharge occurred in East Meadow Brook, Bellmore Creek and Massapequa Creek in response to extensive sewering in Nassau County. The smallest longterm annual discharge to the SSER was from the westernmost stream, Pines Brook, which is in an area in which the water table has been lowered by sewers since 1952. The three largest average annual discharges to the SSER were from the Connetquot River, Carlls River, and Carmans River in Suffolk County; the discharges from each of these streams were at least twice those of the other streams considered in this study.Total nitrogen concentrations in streams show a geographic trend with a general eastward increase in median total nitrogen concentration in Nassau County and a decreasing trend from Massapequa Creek eastward into Suffolk County. Total nitrogen concentrations in streams generally are lowest during summer and highest in winter as a result of seasonal fluctuations in chemical reactions and biological activity. The greatest seasonal difference in median total nitrogen concentration was at Carlls River with values of 3.4 and 4.2 mg/L (milligrams per liter) as N during summer (April through September) and winter (October through March), respectively. Streams affected by the completion of sewer districts show long-term (1971-97) trends of decreasing total nitrogen concentration and streams showing an increase in total nitrogen concentration are in unsewered areas with increased urbanization.Discharges from shallow ground water (upper glacial aquifer) and deep ground water (upper part of Magothy aquifer) were simulated from a ground-water-flow model calibrated to steadystate (1968-83) conditions. Simulated discharges from shallow-ground-water system in Nassau County were 10,700 Mgal/yr (million gallons per year) or 40,500,000 m3/yr (cubic meters per year), and those from Suffolk County were 52,300 Mgal/yr or 198,000,000 m3/yr. Discharges from deep-ground-water system in Nassau County were 4,900 Mgal/yr or 18,500,000 m3/yr, and those in Suffolk County were 12,700 Mgal/yr or 48,200,000 m3/yr.Ground-water concentrations of nitrogen decrease with depth and from west to east. The shallow ground water median nitrogen concentration for each county was determined using 1,155 samples collected at 167 shallow wells (125 feet deep or less) within 1 mile of the shore. The deep ground water median nitrate concentration (nitrate represented almost all of the total nitrogen) for each county was determined using 112 samples collected at 25 deep wells (greater than 125 feet deep) within 1 mile of the shore. The median nitrogen concentration for the shallow and median nitrate concentration for the deep ground water in Nassau County were 3.85 and 0.15 mg/L as N, during 1952–97; the corresponding concentrations for Suffolk County were 1.74 and <0.10 (less than 0.10) mg/L as N, during 1952–97.Nitrogen loads discharged from streams to the SSER for each year during 1972–97 were calculated as the annual total nitrogen concentration multiplied by the annual discharge. These values were calculated only for the seven streams for which sufficient data were available. The largest long-term (1972–97) average annual nitrogen load from Carlls River was 104 ton/yr or 94,300 kg/yr—about twice that of Connetquot River (54 ton/yr or 48,900 kg/yr) and over three times that of Carmans River (33 ton/yr or 29,900 kg/yr). The smallest annual mean nitrogen load was from Pines Brook, which has the lowest annual mean discharge of all streams analyzed.The nitrogen load carried to the SSER by ground-water discharge in shallow-ground-water system in Nassau and Suffolk Counties was calculated as the simulated discharge for each county multiplied by the respective median nitrogen concentration, and loads from deep-ground-water system were calculated as the simulated discharge for each county multiplied by the respective median nitrate concentration. All discharges were obtained from the U.S. Geological Survey's Long Island ground-water-flow model. The resultant nitrogen loads discharged to the SSER from shallow ground water were 172 ton/yr (156,000 kg/yr) from Nassau County and 380 ton/yr (345,000 kg/yr) from Suffolk County; equaling 552 ton/yr entering the SSER. Those from deep ground water were 3 ton/yr (2,700 kg/yr) from Nassau County and <0.5 ton/yr (480 kg/yr) from Suffolk County; equaling about 3.5 ton/yr entering the SSER.The sum of both stream loads and groundwater loads results in the total load to the SSER. The largest calculated total nitrogen load entering the SSER from both streams and ground water occurred in 1979 with a total load of 1,260 ton/yr (1,140,000 kg/yr). The smallest calculated nitrogen load entering the SSER occurred in 1995 with a total load of 725 ton/yr (658,000 kg/yr).

The long-term decrease of 90Sr availability in the environment and its transfer to man after a nuclear fallout.

PubMed

Mück, K; Sinojmeri, M; Whilidal, H; Steger, F

2001-01-01

Due to its long physical half-life, and the fact that its long-term mobility in the environment as well as its radiotoxicity is higher than that of 137Cs, the long-term bio-availability of 90Sr in the environment is of importance with regard to the long-term population exposure after fallout from nuclear weapons detonations or a severe reactor accident. It will also substantially influence the time-span required until re-utilisation of highly contaminated territory is possible again. An assessment of the long-term decrease of the activity concentration in all foodstuffs relevant for internal exposure after severe 90Sr fallout was performed. The observed effective half-lives were approximately 1.8-2.1 years in the first 2-3 years after the end of fallout and 8-10 years in the following three decades. This is equivalent to a biological half-life of about 13.2 years and results in a total 50 year dose of 6.2 times the first year exposure. Due to this decline in 90Sr-availability, the average annual activity intake of 90Sr in Austria has decreased from 840 Bq at the climax of the nuclear weapons tests to about 42 Bq in 1997 for adults, and from 500 Bq to about 35 Bq for 1 year old infants. This is equivalent to a 90Sr ingestion dose of 1.2 microSv for adults and 2.5 microSv for 1 year old infants in 1997 or less than 0.4% of the ingestion dose by natural radionuclides in the diet.

Total suspended particulate matter and toxic elements indoors during cooking with yak dung

NASA Astrophysics Data System (ADS)

Kang, Shichang; Li, Chaoliu; Wang, Feiyue; Zhang, Qianggong; Cong, Zhiyuan

Many herders in the Tibetan Plateau still inherit the traditional lifestyle, including living in tents and burning yak dung for fuel. This short correspondence reports a pilot study on indoor air quality in the nomadic tents in the Nam Co region, inland Tibetan Plateau. The results showed very high concentrations of total suspended particles (TSP), averaging at 4.45 mg m -3 during the cooking/heating period (with daily value of 3.16 mg m -3). Elevated concentrations of toxic element Cd, As and Pb were also found within the tents, averaging 3.16 μg m -3, 35.00 μg m -3, and 81.39 μg m -3 for a day, respectively, which were not only far higher than those of WHO indoor air quality guidelines, but also more than 10 4-10 6 times higher than the outdoor air level in the Nam Co area. The study raises serious concerns over the health of Tibetan herders following their long-term exposure to the tent air.

Economic status and temperature-related mortality in Asia

NASA Astrophysics Data System (ADS)

Lim, Youn-Hee; Bell, Michelle L.; Kan, Haidong; Honda, Yasushi; Guo, Yue-Liang Leon; Kim, Ho

2015-10-01

In developed countries, low latitude and high temperature are positively associated with the population's ability to adapt to heat. However, few studies have examined the effect of economic status on the relationship between long-term exposure to high temperature and health. We compared heterogeneous temperature-related mortality effects relative to the average summer temperature in high-socioeconomic-status (SES) cities to temperature-related effects in low-SES cities. In the first stage of the research, we conducted a linear regression analysis to quantify the mortality effects of high temperature (at or above the 95th percentile) in 32 cities in Taiwan, China, Japan, and Korea. In the second stage, we used a meta-regression to examine the association between mortality risk with average summer temperature and gross domestic product (GDP) per capita. In cities with a low GDP per capita (less than 20,000 USD), the effects of temperature were detrimental to the population if the long-term average summer temperature was high. In contrast, in cities with a high GDP per capita, temperature-related mortality risk was not significantly related to average summer temperature. The relationship between long-term average summer temperature and the short-term effects of high temperatures differed based on the city-level economic status.

Association of modeled long-term personal exposure to ultrafine particles with inflammatory and coagulation biomarkers.

PubMed

Lane, Kevin J; Levy, Jonathan I; Scammell, Madeleine K; Peters, Junenette L; Patton, Allison P; Reisner, Ellin; Lowe, Lydia; Zamore, Wig; Durant, John L; Brugge, Doug

2016-01-01

Long-term exposure to fine particulate matter has been linked to cardiovascular disease and systemic inflammatory responses; however, evidence is limited regarding the effects of long-term exposure to ultrafine particulate matter (UFP, <100nm). We used a cross-sectional study design to examine the association of long-term exposure to near-highway UFP with measures of systemic inflammation and coagulation. We analyzed blood samples from 408 individuals aged 40-91years living in three near-highway and three urban background areas in and near Boston, Massachusetts. We conducted mobile monitoring of particle number concentration (PNC) in each area, and used the data to develop and validate highly resolved spatiotemporal (hourly, 20m) PNC regression models. These models were linked with participant time-activity data to determine individual time-activity adjusted (TAA) annual average PNC exposures. Multivariable regression modeling and stratification were used to assess the association between TAA-PNC and single peripheral blood measures of high-sensitivity C-reactive protein (hsCRP), interleukin-6 (IL-6), tumor-necrosis factor alpha receptor II (TNFRII) and fibrinogen. After adjusting for age, sex, education, body mass index, smoking and race/ethnicity, an interquartile-range (10,000particles/cm(3)) increase in TAA-PNC had a positive non-significant association with a 14.0% (95% CI: -4.6%, 36.2%) positive difference in hsCRP, an 8.9% (95% CI: -0.4%, 10.9%) positive difference in IL-6, and a 5.1% (95% CI: -0.4%, 10.9%) positive difference in TNFRII. Stratification by race/ethnicity revealed that TAA-PNC had larger effect estimates for all three inflammatory markers and was significantly associated with hsCRP and TNFRII in white non-Hispanic, but not East Asian participants. Fibrinogen had a negative non-significant association with TAA-PNC. Our findings suggest an association between annual average near-highway TAA-PNC and subclinical inflammatory markers of CVD risk. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Pleistocene tropical Pacific temperature sensitivity to radiative greenhouse gas forcing

NASA Astrophysics Data System (ADS)

Dyck, K. A.; Ravelo, A. C.

2011-12-01

How high will Earth's global average surface temperature ultimately rise as greenhouse gas concentrations increase in the future? One way to tackle this question is to compare contemporaneous temperature and greenhouse gas concentration data from paleoclimate records, while considering that other radiative forcing mechanisms (e.g. changes in the amount and distribution of incoming solar radiation associated with changes in the Earth's orbital configuration) also contribute to surface temperature change. Since the sensitivity of surface temperature varies with location and latitude, here we choose a central location representative of the west Pacific warm pool, far from upwelling regions or surface temperature gradients in order to minimize climate feedbacks associated with high-latitude regions or oceanic dynamics. The 'steady-state' or long-term temperature change associated with greenhouse gas radiative forcing is often labeled as equilibrium (or 'Earth system') climate sensitivity to the doubling of atmospheric greenhouse gas concentration. Climate models suggest that Earth system sensitivity does not change dramatically over times when CO2 was lower or higher than the modern atmospheric value. Thus, in our investigation of the changes in tropical SST, from the glacial to interglacial states when greenhouse gas forcing nearly doubled, we use Late Pleistocene paleoclimate records to constrain earth system sensitivity for the tropics. Here we use Mg/Ca-paleothermometry using the foraminifera G. ruber from ODP Site 871 from the past 500 kyr in the western Pacific warm pool to estimate tropical Pacific equilibrium climate sensitivity to a doubling of greenhouse gas concentrations to be ~4°C. This tropical SST sensitivity to greenhouse gas forcing is ~1-2°C higher than that predicted by climate models of past glacial periods or future warming for the tropical Pacific. Equatorial Pacific SST sensitivity may be higher than predicted by models for a number of reasons. First, models may not be adequately representing long-term deep ocean feedbacks. Second, models may incorrectly parameterize tropical cloud (or other short-term) feedback processes. Lastly, either paleo-temperature or radiative forcing may have been incorrectly estimated (e.g. through calibration of paleoclimate evidence for temperature change). Since theory suggests that surface temperature in the high latitudes is more sensitive to radiative forcing changes than surface temperature in the tropics, the results of this study also imply that globally averaged Earth system sensitivity to greenhouse gas concentrations may be higher than most climate models predict.

Acclimation of two tomato species to high atmospheric CO sub 2 : I. Sugar and starch concentrations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yelle, S.; Beeson, R.C. Jr.; Trudel, M.J.

Lycopersicon esculentum Mill. cv Vedettos and Lycopersicon chmielewskii Rick, LA1028, were exposed to two CO{sub 2} concentrations for 10 weeks. Tomato plants grown at 900 microliters per liter contained more starch and more sugars than the control. However, we found no significant accumulation of starch and sugars in the young leaves of L. esculentum exposed to high CO{sub 2}. Carbon exchange rates were significantly higher in CO{sub 2}-enriched plants for the first few weeks of treatment but thereafter decreased as tomato plants acclimated to high atmospheric CO{sub 2}. This indicates that the long-term decline of photosynthetic efficiency of leaf 5more » cannot be attributed to an accumulation of sugar and/or starch. The average concentration of starch in leaves 5 and 9 was always higher in L. esculentum than in L. chmielewskii (151.7% higher). A higher proportion of photosynthates was directed into starch for L. esculentum than for L. chmielewskii. However, these characteristics did not improve the long-term photosynthetic efficiency of L. chmielewskii grown at high CO{sub 2} when compared with L. esculentum. The chloroplasts of tomato plants exposed to the higher CO{sub 2} concentration exhibited a marked accumulation of starch. The results reported here suggest that starch and/or sugar accumulation under high CO{sub 2} cannot entirely explain the loss of photosynthetic efficiency of high CO{sub 2}-grown plants.« less

Changes in nitrate concentrations and loads in United Kingdom watersheds since 1868: Evidence for land use change as a dominant driver and ineffective mitigation

NASA Astrophysics Data System (ADS)

Whelan, M. J.; Burt, T. P.; Howden, N. K.; Worrall, F.

2012-12-01

Nitrate concentrations and fluxes in many of the world's rivers have increased over the latter part of the 20th Century leading to freshwater and, more frequently, marine eutrophication. This has largely been linked to agricultural intensification which has increased food production via a combination of improved methods, crop varieties, pest control technologies, mechanisation and fertiliser use. The area of land under intensive production has also increased in many watersheds. Here we analyse long term water quality records from a number of UK rivers to assess temporal patterns of nitrate concentrations and fluxes and to identify driving factors. The data, which include the world's longest record of nitrate concentrations from the River Thames, London (1868 to 2008), show that dramatic and sustained increases in nitrate concentrations and fluxes occurred after periods of substantial land use change including the conversion of significant areas of permanent pasture to arable production in the 1940s and 1960s and increases in fertiliser use in the 1960s. Grassland to arable conversion can release large quantities of nitrate due to the enhanced mineralisation of the extra soil organic nitrogen which accumulates in pasture systems. Recent attempts to reverse these increases, such as widespread restrictions of nitrogen inputs have, thus far, been relatively ineffective, although there have been recent indications that levels have stabilised in some watersheds. Our analysis clearly shows the dominance of land use change over other potential drivers such as waste water emission, climatic and hydrological changes and suggests that current measures for the mitigation of large-scale diffuse pollution based on limiting fertiliser use are not drastic enough to reverse significantly the increases in riverine nitrate concentrations which have been observed. Analysis of the long term data also shows that trend detection is problematic for periods less than about 15 years, without a longer term historical context. The data and associated analysis support the continued maintenance of very long benchmark monitoring sites to identify trends and adequately assess the drivers of environmental change. Nitrate concentrations measured in the river Thames since 1868 showing drammatic increases in the latter half of the 20th century. Red line shows annual average concentration.

DEVELOPMENT OF ALTERNATE PERFORMANCE STANDARD FOR RADON RESISTANT CONSTRUCTION BASED ON SHORT-TERM/LONG- TERM INDOOR RADON CONCENTRATIONS - VOLUME 2: APPENDICES

EPA Science Inventory

The report gives results of a study of short- and long-term variations in radon concentration in about 80 houses in Florida. The study involves comparative sampling using the most common radon measurement technologies during the past year. he study, providing the most detailed da...

DEVELOPMENT OF ALTERNATE PERFORMANCE STANDARD FOR RADON RESISTANT CONSTRUCTION BASED ON SHORT-TERM/LONG- TERM INDOOR RADON CONCENTRATIONS - VOLUME 1: TECHNICAL REPORT

EPA Science Inventory

The report gives results of a study of short- and long-term variations in radon concentration in about 80 houses in Florida. The study involves comparative sampling using the most common radon measurement technologies during the past year. he study, providing the most detailed da...

Methods to assess carbonaceous aerosol sampling artifacts for IMPROVE and other long-term networks.

PubMed

Watson, John G; Chow, Judith C; Chen, L W Antony; Frank, Neil H

2009-08-01

Volatile organic compounds (VOCs) and semi-volatile organic compounds (SVOCs) adsorb to quartz fiber filters during fine and coarse particulate matter (PM2.5 and PM10, respectively) sampling for thermal/optical carbon analysis that measures organic carbon (OC) and elemental carbon (EC). Particulate SVOCs can evaporate after collection, with a small portion adsorbed within the filter. Adsorbed organic gases are measured as particulate OC, so passive field blanks, backup filters, prefilter organic denuders, and regression methods have been applied to compensate for positive OC artifacts in several long-term chemical speciation networks. Average backup filter OC levels from the Interagency Monitoring of Protected Visual Environments (IMPROVE) network were approximately 19% higher than field blank values. This difference is within the standard deviation of the average and likely results from low SVOC concentrations in the rural to remote environments of most IMPROVE sites. Backup filters from an urban (Fort Meade, MD) site showed twice the OC levels of field blanks. Sectioning backup filters from top to bottom showed nonuniform OC densities within the filter, contrary to the assumption that VOCs and SVOCs on a backup filter equal those on the front filter. This nonuniformity may be partially explained by evaporation and readsorption of vapors in different parts of the front and backup quartz fiber filter owing to temperature, relative humidity, and ambient concentration changes throughout a 24-hr sample duration. OC-PM2.5 regression analysis and organic denuder approaches demonstrate negative sampling artifact from both Teflon membrane and quartz fiber filters.

Effects of open-top chambers on 'Valencia' orange trees

DOE Office of Scientific and Technical Information (OSTI.GOV)

Olszyk, D.M.; Takemoto, B.K.; Kats, G.

1992-01-01

Young 'Valencia' orange trees (Citrus sinensis(L) Osbeck) were grown for four years in large open-top chambers with ambient (nonfiltered) air or in outside air to determine any effects of the chambers on the air pollutant susceptibility of the trees. Long-term ozone average concentrations (12 hours, growing season) were 8% lower, and cumulative ozone dose (hourly values >0.1 microL/L) was 29% lower in ambient chambers compared to outside air. Fruit yields were much higher (>39%) for ambient chamber trees than for outside trees over three harvests, due at least partly to less fruit drop during the growing season for ambient chambermore » trees. Ambient chamber trees were much larger than outside trees and produced over twice as much leaf material over four years of study. Leaves on ambient chamber trees were larger and less dense than on outside trees. Leaves on ambient chamber trees were under more stress than leaves on outside trees during summer months; with lower stomatal conductances (14% average) and transpiration rates (12%), and more negative leaf water pressure potentials (28%). In contrast, leaves on ambient chamber trees had higher net photosynthetic rates (13%) and higher leaf starch concentrations prior to tree flowering (31%), than leaves on outside trees. While these results indicated large long-term impacts on tree growth which must be considered when using open-top chambers, they did not indicate any net effect of chambers on the air pollutant susceptibility of trees which would limit the usefulness of chamber tree data for air quality impact assessment purposes.« less

Benzathine penicillin G: a model for long-term pharmacokinetic comparison of parenteral long-acting formulations.

PubMed

Shahbazi, M A; Azimi, K; Hamidi, M

2013-04-01

  Long-acting intramuscular penicillin G injection is an important product for the management of some severe infections. However, testing the bioequivalence of such long-acting formulations is difficult. Our aim was to undertake such a test using a generic formulation containing 1 200 000 IU of benzathine penicillin G powder and an innovator's product (Retarpen(®) 1·2 million units; Sandoz, Switzerland).   In an open, double-blind, randomized, two-periods, two-group crossover study, 12 healthy male volunteers received both formulations of benzathine penicillin G on two different days with a 5-month washout period between the doses and a sampling period of over 500 h. A simple, sensitive and rapid high-performance liquid chromatography (HPLC)-UV method was developed and validated for determination of penicillin G plasma concentrations and other pharmacokinetic (PK) parameters.   The analytical method used produced linear responses within a wide analyte concentration range with average within-run and between-run variations of below 15% with acceptable recovery, accuracy and sensitivity. The primary PK parameters we used were maximum plasma concentration (Cmax ), time to reach the maximal concentration (Tmax ) and the area under the plasma concentration vs. time curve from time zero to the last sampling time (AUC0→t ) using a standard non-compartmental approach. Based on these parameters, the two formulations were bioequivalent.   We illustrate the bioequivalence testing of a very long-acting product. The data indicate that the generic test formulation and the branded reference formulation were bioequivalent in fasting healthy Iranian male volunteers. © 2013 Blackwell Publishing Ltd.

Long-term Internal Variability of the Tropical Pacific Atmosphere-Ocean System

NASA Astrophysics Data System (ADS)

Hadi Bordbar, Mohammad; Martin, Thomas; Park, Wonsun; Latif, Mojib

2016-04-01

The tropical Pacific has featured some remarkable trends during the recent decades such as an unprecedented strengthening of the Trade Winds, a strong cooling of sea surface temperatures (SST) in the eastern and central part, thereby slowing global warming and strengthening the zonal SST gradient, and highly asymmetric sea level trends with an accelerated rise relative to the global average in the western and a drop in the eastern part. These trends have been linked to an anomalously strong Pacific Walker Circulation, the major zonal atmospheric overturning cell in the tropical Pacific sector, but the origin of the strengthening is controversial. Here we address the question as to whether the recent decadal trends in the tropical Pacific atmosphere-ocean system are within the range of internal variability, as simulated in long unforced integrations of global climate models. We show that the recent trends are still within the range of long-term internal decadal variability. Further, such variability strengthens in response to enhanced greenhouse gas concentrations, which may further hinder detection of anthropogenic climate signals in that region.

Assessment of long-term gas sampling design at two commercial manure-belt layer barns.

PubMed

Chai, Li-Long; Ni, Ji-Qin; Chen, Yan; Diehl, Claude A; Heber, Albert J; Lim, Teng T

2010-06-01

Understanding temporal and spatial variations of aerial pollutant concentrations is important for designing air quality monitoring systems. In long-term and continuous air quality monitoring in large livestock and poultry barns, these systems usually use location-shared analyzers and sensors and can only sample air at limited number of locations. To assess the validity of the gas sampling design at a commercial layer farm, a new methodology was developed to map pollutant gas concentrations using portable sensors under steady-state or quasi-steady-state barn conditions. Three assessment tests were conducted from December 2008 to February 2009 in two manure-belt layer barns. Each barn was 140.2 m long and 19.5 m wide and had 250,000 birds. Each test included four measurements of ammonia and carbon dioxide concentrations at 20 locations that covered all operating fans, including six of the fans used in the long-term sampling that represented three zones along the lengths of the barns, to generate data for complete-barn monitoring. To simulate the long-term monitoring, gas concentrations from the six long-term sampling locations were extracted from the 20 assessment locations. Statistical analyses were performed to test the variances (F-test) and sample means (t test) between the 6- and 20-sample data. The study clearly demonstrated ammonia and carbon dioxide concentration gradients that were characterized by increasing concentrations from the west to east ends of the barns following the under-cage manure-belt travel direction. Mean concentrations increased from 7.1 to 47.7 parts per million (ppm) for ammonia and from 2303 to 3454 ppm for carbon dioxide from the west to east of the barns. Variations of mean gas concentrations were much less apparent between the south and north sides of the barns, because they were 21.2 and 20.9 ppm for ammonia and 2979 and 2951 ppm for carbon dioxide, respectively. The null hypotheses that the variances and means between the 6- and 20-sample data were equal at alpha = 0.05 (P > 0.05) were accepted for both gases. The results proved that the long-term gas sampling design was valid in this instance and suggested that the gas sampling design in these two barns was one of the best on the basis of available long-term monitoring instrumentation at reasonable cost.

Sources and Transport of Nutrients, Organic Carbon, and Chlorophyll-a in the San Joaquin River Upstream of Vernalis, California, during Summer and Fall, 2000 and 2001

USGS Publications Warehouse

Kratzer, Charles R.; Dileanis, Peter D.; Zamora, Celia; Silva, Steven R.; Kendall, Carol; Bergamaschi, Brian A.; Dahlgren, Randy A.

2004-01-01

Oxidizable materials from the San Joaquin River upstream of Vernalis can contribute to low dissolved oxygen episodes in the Stockton Deep Water Ship Channel that can inhibit salmon migration in the fall. The U.S. Geological Survey collected and analyzed samples at four San Joaquin River sites in July through October 2000 and June through November 2001, and at eight tributary sites in 2001. The data from these sites were supplemented with data from samples collected and analyzed by the University of California at Davis at three San Joaquin River sites and eight tributary sites as part of a separate study. Streamflows in the San Joaquin River were slightly above the long-term average in 2000 and slightly below average in 2001. Nitrate loads at Vernalis in 2000 were above the long-term average, whereas loads in 2001 were close to average. Total nitrogen loads in 2000 were slightly above average, whereas loads in 2001 were slightly below average. Total phosphorus loads in 2000 and 2001 were well below average. These nutrient loads correspond with the flow-adjusted concentration trends--nitrate concentrations significantly increased since 1972 (p 0.05). Loading rates of nutrients and dissolved organic carbon increased in the San Joaquin River in the fall with the release of wetland drainage into Mud Slough and with increased reservoir releases on the Merced River. During August 2000 and September 2001, the chlorophyll-a loading rates and concentrations in the San Joaquin River declined and remained low during the rest of the sampling period. The most significant tributary sources of nutrients were the Tuolumne River, Harding Drain, and Mud Slough. The most significant tributary sources of dissolved organic carbon were Salt Slough, Mud Slough, and the Tuolumne and Stanislaus Rivers. Compared with nutrients and dissolved organic carbon, the tributaries were minor sources of chlorophyll-a, suggesting that most of the chlorophyll-a was produced in the San Joaquin River rather than its tributaries. On the basis of the carbon-to-nitrogen ratios and the d13C of particulate organic matter in the San Joaquin River and tributaries, the particulate organic matter in the river was mostly phytoplankton. On the basis of the d15N values of the particulate organic matter, and of total dissolved nitrogen and nitrate, the nitrate in the San Joaquin River probably was a significant nutrient source for the phytoplankton. The range of d15N and d18O values of nitrate in the San Joaquin River and tributaries suggest that animal waste or sewage was a significant source of nitrate in the river at the time the samples were collected.

Carotid Intima-Media Thickness and Long-Term Exposure to Traffic-Related Air Pollution in Middle-Aged Residents of Taiwan: A Cross-Sectional Study.

PubMed

Su, Ta-Chen; Hwang, Juey-Jen; Shen, Yu-Cheng; Chan, Chang-Chuan

2015-08-01

Associations between long-term exposure to air pollution and carotid intima-media thickness (CIMT) have inconsistent findings. In this study we aimed to evaluate association between 1-year average exposure to traffic-related air pollution and CIMT in middle-aged adults in Asia. CIMT was measured in Taipei, Taiwan, between 2009 and 2011 in 689 volunteers 35-65 years of age who were recruited as the control subjects of an acute coronary heart disease cohort study. We applied land-use regression models developed by the European Study of Cohorts for Air Pollution Effects (ESCAPE) to estimate each subject's 1-year average exposure to traffic-related air pollutants with particulate matter diameters ≤ 10 μm (PM10) and ≤ 2.5 μm (PM2.5) and the absorbance levels of PM2.5 (PM2.5abs), nitrogen dioxide (NO2), and nitrogen oxides (NOx) in the urban environment. One-year average air pollution exposures were 44.21 ± 4.19 μg/m3 for PM10, 27.34 ± 5.12 μg/m3 for PM2.5, and (1.97 ± 0.36) × 10-5/m for PM2.5abs. Multivariate regression analyses showed average percentage increases in maximum left CIMT of 4.23% (95% CI: 0.32, 8.13) per 1.0 × 10-5/m increase in PM2.5abs; 3.72% (95% CI: 0.32, 7.11) per 10-μg/m3 increase in PM10; 2.81% (95% CI: 0.32, 5.31) per 20-μg/m3 increase in NO2; and 0.74% (95% CI: 0.08, 1.41) per 10-μg/m3 increase in NOx. The associations were not evident for right CIMT, and PM2.5 mass concentration was not associated with the outcomes. Long-term exposures to traffic-related air pollution of PM2.5abs, PM10, NO2, and NOx were positively associated with subclinical atherosclerosis in middle-aged adults.

Potential health benefits of controlling dust emissions in Beijing.

PubMed

Meng, Jing; Liu, Junfeng; Fan, Songmiao; Kang, Chuyun; Yi, Kan; Cheng, Yanli; Shen, Xing; Tao, Shu

2016-06-01

Although the adverse impact of fine particulate matter (i.e., PM2.5) on human health has been well acknowledged, little is known of the health effects of its specific constituents. Over the past decade, the annual average dust concentrations in Beijing were approximately ∼14 μg m(-3), a value that poses a great threat to the city's 20 million residents. In this study, we quantify the potential long-term health damages in Beijing resulting from the dust exposure that occurred from 2000 to 2011. Each year in Beijing, nearly 4000 (95% CI: 1000-7000) premature deaths may be associated with long-term dust exposure, and ∼20% of these deaths are attributed to lung cancer. A decomposition analysis of the inter-annual variability of premature deaths in Beijing indicates that dust concentrations determine the year-to-year tendency, whereas population growth and lung cancer mortality rates drive the increasing tendency of premature death. We suggest that if Beijing takes effective measures towards reducing dust concentrations (e.g., controlling the resuspension of road dust and the fugitive dust from construction sites) to a level comparable to that of New York City's, the associated premature deaths will be significantly reduced. This recommendation offers "low-hanging fruit" suggestions for pollution control that would greatly benefit the public health in Beijing. Copyright © 2016 Elsevier Ltd. All rights reserved.

Migration and health risks of nonylphenol and bisphenol a in soil-winter wheat systems with long-term reclaimed water irrigation.

PubMed

Wang, Shiyu; Liu, Fei; Wu, Wenyong; Hu, Yaqi; Liao, Renkuan; Chen, Gaoting; Wang, Jiulong; Li, Jialin

2018-04-12

Reclaimed water reuse has become an important means of alleviating agricultural water shortage worldwide. However, the presence of endocrine disrupters has roused up considerable attention. Barrel test in farmland was conducted to investigate the migration of nonylphenol (NP) and bisphenol A (BPA) in soil-winter wheat system simulating reclaimed water irrigation. Additionally, the health risks on humans were assessed based on US EPA risk assessment model. The migration of NP and BPA decreased from the soil to the winter wheat; the biological concentration factors (BCFs) of NP and BPA in roots, stems, leaves, and grains all decreased with their added concentrations in soils. The BCFs of NP and BPA in roots were greatest (0.60-5.80 and 0.063-1.45, respectively). The average BCFs of NP and BPA in winter wheat showed negative exponential relations to their concentrations in soil. The amounts of NP and BPA in soil-winter wheat system accounted for 8.99-28.24% and 2.35-4.95%, respectively, of the initial amounts added into the soils. The hazard quotient (HQ) for children and adults ranged between 10 -6 and 1, so carcinogenic risks could be induced by ingesting winter wheat grains under long-term reclaimed water irrigation. Copyright © 2018 Elsevier Inc. All rights reserved.

Long-term maintenance needs planning.

DOT National Transportation Integrated Search

2005-09-01

This research contributes to Kentucky's knowledge base of long-term maintenance needs in two parts. Part I presents an estimate of the average revenue needed to maintain four categories of highway in the first fifteen years after each is built or res...

Fluvial sediment in the little Arkansas River basin, Kansas

USGS Publications Warehouse

Albert, C.D.; Stramel, G.J.

1966-01-01

Characteristics and transport of sediment in the Little Arkansas River basin in south-central Kansas were studied to determine if the water from the river could be used as a supplemental source for municipal supply or would provide adequate recharge to aquifers that are sources of municipal and agricultural water supplies. During periods when overland 1low contributed a significant amount to streamflow, the suspended sediment in the Little Arkansas River at Valley Center averaged about 85 percent of clay, about 13 percent of silt, and about 2 percent of sand. The average annual suspended-sediment discharge for the water years 1958, 1959, 1960, and 1961 was about 306,000 tons, and about 80 percent of the load was transported during 133 days of the 1,461-day period. The average daily water discharge of 352 cubic feet per second for the period 1958-61 was more than the long-term (i}9-year) average of 245 cfs; therefore, the average annual sediment load for 1958-61 was probably greater than the average annual load for the same long-term period. Studies of seepage in a part of the channel of Kisiwa Creek indicated that an upstream gravel-pit operation yielded clays which, when deposited in the channel, reduced seepage. A change in plant operation and subsequent runoff that removed the deposited clays restored natural seepage conditions. Experiments by the Wichita Water Department showed that artificial recharge probably cannot be accomplished by using raw turbid water that is injected into wells or by using pits. Recharge by raw turbid water on large permeable areas or by seepage canals may be feasible. Studies of chemical quality of surface water at several sites in the Little Arkansas River basin indicate that Turkey. Creek is a major contributor of chloride and other dissolved solids to the Little Arkansas River and that the dissolved-solids content is probably highest during low-flow periods when suspended-sediment concentration is low. Data collected by the Wichita Water Department indicate that chloride concentrations are diminishing with time at sampled locations. and they receive recharge from rainwater and snowmelt moving through overlying alluvium and from storage in the De Chelly sandstone which encloses the east half of the diatreme. The quality of water from all areas is suitable for domestic use. However, special treatment may be necessary to make the water suitable for pulp processing.

Relations of long-term and contemporary lipid levels and lipid genetic risk scores with coronary artery calcium in the framingham heart study.

PubMed

Tsao, Connie W; Preis, Sarah Rosner; Peloso, Gina M; Hwang, Shih-Jen; Kathiresan, Sekar; Fox, Caroline S; Cupples, L Adrienne; Hoffmann, Udo; O'Donnell, Christopher J

2012-12-11

This study evaluated the association of timing of lipid levels and lipid genetic risk score (GRS) with subclinical atherosclerosis. Atherosclerosis is a slowly progressive disorder influenced by suboptimal lipid levels. Long-term versus contemporary lipid levels may more strongly impact the development of coronary artery calcium (CAC). Framingham Heart Study (FHS) Offspring Cohort participants (n = 1,156, 44% male, 63 ± 9 years) underwent serial fasting lipids (low-density lipoprotein cholesterol [LDL-C], high-density lipoprotein, and triglycerides), Exam 1 (1971 to 1975) to Exam 7 (1998 to 2001). FHS Third Generation Cohort participants (n = 1,954, 55% male, 45 ± 6 years) had fasting lipid profiles assessed, 2002 to 2005. Computed tomography (2002 to 2005) measured CAC. Lipid GRSs were computed from significantly associated single-nucleotide polymorphisms. The association between early, long-term average, and contemporary lipids, and lipid GRS with elevated CAC was assessed using logistic regression. In FHS Offspring, Exam 1 and long-term average as compared with Exam 7 lipid measurements, including untreated lipid levels, were strongly associated with elevated CAC. In the FHS Third Generation, contemporary lipids were associated with CAC. The LDL-C GRS was associated with CAC (age-/sex-adjusted odds ratio: 1.14, 95% confidence interval: 1.00 to 1.29, p = 0.04). However, addition of the GRS to the lipid models did not result in a significant increase in the odds ratio or C-statistic for any lipid measure. Early and long-term average lipid levels, as compared with contemporary measures, are more strongly associated with elevated CAC. Lipid GRS was associated with lipid levels but did not predict elevated CAC. Adult early and long-term average lipid levels provide important information when assessing subclinical atherosclerosis and cardiovascular risk. Copyright © 2012 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Long-term mesalamine maintenance in ulcerative colitis: which is more important? Adherence or daily dose.

PubMed

Khan, Nabeel; Abbas, Ali M; Koleva, Yordanka N; Bazzano, Lydia A

2013-05-01

There are limited data about the long-term follow-up of patients with ulcerative colitis (UC) maintained on high versus low doses of mesalamine. We evaluated the best long-term average daily dose that would keep the disease in remission. Nationwide ulcerative colitis data were obtained from the Veterans Affairs health care system for the period 2001 to 2011. Those who started mesalamine maintenance during this period were included. Average daily dose and the level of adherence were assessed for the period between the first mesalamine dispense and the date of first flare defined as the first filling of 40 mg/day or more of oral prednisone or any dose of intravenous steroids. Patients with ulcerative colitis maintained on an average daily dose 2.4 to 2.8 g/day (low dose) were compared with 4.4 to 4.8 g/day (high dose). Adherence was assessed using continuous single interval medication availability indicator. We included 4452 patients with a median follow-up of 6 years. There was no significant reduction in the risk of flares when comparing high versus low average mesalamine dose among patients with high [hazard ratio = 0.96, P = 0.8)] and medium (hazard ratio = 0.74, P = 0.17) adherence. However, there was a significant reduction in the risk of flares with high dose of mesalamine among patients with low adherence (hazard ratio = 0.28, P = 0.003). Our data show that when starting a patient on mesalamine, there is no difference in the long-term flare risk between low versus high average daily dose as long as the patients have a high to moderate level of adherence.

Optimal chemotactic responses in stochastic environments

PubMed Central

Godány, Martin

2017-01-01

Although the “adaptive” strategy used by Escherichia coli has dominated our understanding of bacterial chemotaxis, the environmental conditions under which this strategy emerged is still poorly understood. In this work, we study the performance of various chemotactic strategies under a range of stochastic time- and space-varying attractant distributions in silico. We describe a novel “speculator” response in which the bacterium compare the current attractant concentration to the long-term average; if it is higher then they tumble persistently, while if it is lower than the average, bacteria swim away in search of more favorable conditions. We demonstrate how this response explains the experimental behavior of aerobically-grown Rhodobacter sphaeroides and that under spatially complex but slowly-changing nutrient conditions the speculator response is as effective as the adaptive strategy of E. coli. PMID:28644830

Long-term study of urban ultrafine particles and other pollutants

NASA Astrophysics Data System (ADS)

Wang, Yungang; Hopke, Philip K.; Chalupa, David C.; Utell, Mark J.

2011-12-01

Continuous measurements of number size distributions of ultrafine particles (UFPs) and other pollutants (PM 2.5, SO 2, CO and O 3) have been performed in Rochester, New York since late November 2001. The 2002-2009 average number concentrations of particles in three size ranges (10-50 nm, 50-100 nm and 100-500 nm) were 4730 cm -3, 1838 cm -3, and 1073 cm -3, respectively. The lowest annual average number concentrations of particles in 10-50 nm and 50-100 nm were observed during 2008-2009. The lowest monthly average number concentration of 10-50 nm particles was observed in July and the highest in February. The daily patterns of 10-50 nm particles had two peaks at early morning (7-8 AM) and early afternoon (2 PM). There was a distinct declining trend in the peak number concentrations from 2002-2005 to 2008-2009. Large reductions in SO 2 concentrations associated with northerly winds between 2007 and 2009 were observed. The most significant annual decrease in the frequency of morning particle nucleation was observed from 2005 to 2007. The monthly variation in the morning nucleation events showed a close correlation with number concentrations of 10-50 nm particles ( r = 0.89). The frequency of the local SO 2-related nucleation events was much higher before 2006. All of these results suggest significant impacts of highway traffic and industrial sources. The decrease in particle number concentrations and particle nucleation events likely resulted from a combination of the U.S. EPA 2007 Heavy-Duty Highway Rule implemented on October 1, 2006, the closure of a large coal-fired power plant in May 2008, and the reduction of Eastman Kodak emissions.

Estimating pesticide exposure from dietary intake and organic food choices: the Multi-Ethnic Study of Atherosclerosis (MESA).

PubMed

Curl, Cynthia L; Beresford, Shirley A A; Fenske, Richard A; Fitzpatrick, Annette L; Lu, Chensheng; Nettleton, Jennifer A; Kaufman, Joel D

2015-05-01

Organophosphate pesticide (OP) exposure to the U.S. population is dominated by dietary intake. The magnitude of exposure from diet depends partly on personal decisions such as which foods to eat and whether to choose organic food. Most studies of OP exposure rely on urinary biomarkers, which are limited by short half-lives and often lack specificity to parent compounds. A reliable means of estimating long-term dietary exposure to individual OPs is needed to assess the potential relationship with adverse health effects. We assessed long-term dietary exposure to 14 OPs among 4,466 participants in the Multi-Ethnic Study of Atherosclerosis, and examined the influence of organic produce consumption on this exposure. Individual-level exposure was estimated by combining information on typical intake of specific food items with average OP residue levels on those items. In an analysis restricted to a subset of participants who reported rarely or never eating organic produce ("conventional consumers"), we assessed urinary dialkylphosphate (DAP) levels across tertiles of estimated exposure (n = 480). In a second analysis, we compared DAP levels across subgroups with differing self-reported organic produce consumption habits (n = 240). Among conventional consumers, increasing tertile of estimated dietary OP exposure was associated with higher DAP concentrations (p < 0.05). DAP concentrations were also significantly lower in groups reporting more frequent consumption of organic produce (p < 0.02). Long-term dietary exposure to OPs was estimated from dietary intake data, and estimates were consistent with DAP measurements. More frequent consumption of organic produce was associated with lower DAPs.

STUDY OF RADIATION EXPOSURE DUE TO RADON, THORON AND PROGENY IN THE INDOOR ENVIRONMENT OF YAMUNA AND TONS VALLEYS OF GARHWAL HIMALAYA.

PubMed

Prasad, Mukesh; Rawat, Mukesh; Dangwal, Anoop; Prasad, Ganesh; Mishra, Rosaline; Ramola, R C

2016-10-01

Long-term measurements of indoor radon, thoron and their progeny concentrations have been carried out in dwellings of Yamuna and Tons Valleys of Uttarkashi, Garhwal Himalaya to investigate the health risk associated with inhalation of radon, thoron and progeny. The experimentally determined values of radon, thoron and progeny concentrations were used to estimate the annual inhalation doses and annual effective doses. The annual inhalation dose has been found to vary from 0.8 to 3.9 mSv y -1 with an average of 1.8 mSv y -1 The annual effective dose from the exposure to radon and its progeny in the study area has been found to vary from 0.1 to 2.4 mSv with an average of 1.2±0.6 mSv. Similarly, the annual effective dose due to thoron and its progeny has been found to vary from 0.2 to 1.5 mSv with an average of 0.6±0.4. The measurement techniques and results obtained are discussed in detail. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Long-term culture of rat hippocampal neurons at low density in serum-free medium: combination of the sandwich culture technique with the three-dimensional nanofibrous hydrogel PuraMatrix.

PubMed

Kaneko, Ai; Sankai, Yoshiyuki

2014-01-01

The primary culture of neuronal cells plays an important role in neuroscience. There has long been a need for methods enabling the long-term culture of primary neurons at low density, in defined serum-free medium. However, the lower the cell density, the more difficult it is to maintain the cells in culture. Therefore, we aimed to develop a method for long-term culture of neurons at low density, in serum-free medium, without the need for a glial feeder layer. Here, we describe the work leading to our determination of a protocol for long-term (>2 months) primary culture of rat hippocampal neurons in serum-free medium at the low density of 3×10(4) cells/mL (8.9×10(3) cells/cm2) without a glial feeder layer. Neurons were cultured on a three-dimensional nanofibrous hydrogel, PuraMatrix, and sandwiched under a coverslip to reproduce the in vivo environment, including the three-dimensional extracellular matrix, low-oxygen conditions, and exposure to concentrated paracrine factors. We examined the effects of varying PuraMatrix concentrations, the timing and presence or absence of a coverslip, the timing of neuronal isolation from embryos, cell density at plating, medium components, and changing the medium or not on parameters such as developmental pattern, cell viability, neuronal ratio, and neurite length. Using our method of combining the sandwich culture technique with PuraMatrix in Neurobasal medium/B27/L-glutamine for primary neuron culture, we achieved longer neurites (≥3,000 µm), greater cell viability (≥30%) for 2 months, and uniform culture across the wells. We also achieved an average neuronal ratio of 97%, showing a nearly pure culture of neurons without astrocytes. Our method is considerably better than techniques for the primary culture of neurons, and eliminates the need for a glial feeder layer. It also exhibits continued support for axonal elongation and synaptic activity for long periods (>6 weeks).

Air radon concentration decrease in a waste water treatment plant.

PubMed

Juste, B; Ortiz, J; Verdú, G; Martorell, S

2015-06-01

(222)Rn is a naturally occurring gas created from the decay of (226)Ra. The long-term health risk of breathing radon is lung cancer. One particular place where indoor radon concentrations can exceed national guidelines is in wastewater treatment plants (WWTPs) where treatment processes may contribute to ambient airborne concentrations. The aim of this paper was to study the radon concentration decrease after the application of corrective measures in a Spanish WWTP. According to first measures, air radon concentration exceeded International Commission Radiologica1 Protection (ICRP) normative (recommends intervention between 400 and 1000 Bq m(-3)). Therefore, the WWTP improved mechanical forced ventilation to lower occupational exposure. This measure allowed to increase the administrative controls, since the limitation of workers access to the plant changed from 2 h d(-1) (considering a maximum permissible dose of 20 mSv y(-1) averaged over 5 y) to 7 h d(-1). © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Interrupted time series analysis of children’s blood lead levels: A case study of lead hazard control program in Syracuse, New York

PubMed Central

Shao, Liyang; Zhang, Lianjun; Zhen, Zhen

2017-01-01

Children’s blood lead concentrations have been closely monitored over the last two decades in the United States. The bio-monitoring surveillance data collected in local agencies reflected the local temporal trends of children’s blood lead levels (BLLs). However, the analysis and modeling of the long-term time series of BLLs have rarely been reported. We attempted to quantify the long-term trends of children’s BLLs in the city of Syracuse, New York and evaluate the impacts of local lead poisoning prevention programs and Lead Hazard Control Program on reducing the children’s BLLs. We applied interrupted time series analysis on the monthly time series of BLLs surveillance data and used ARMA (autoregressive and moving average) models to measure the average children’s blood lead level shift and detect the seasonal pattern change. Our results showed that there were three intervention stages over the past 20 years to reduce children’s BLLs in the city of Syracuse, NY. The average of children’s BLLs was significantly decreased after the interventions, declining from 8.77μg/dL to 3.94μg/dL during1992 to 2011. The seasonal variation diminished over the past decade, but more short term influences were in the variation. The lead hazard control treatment intervention proved effective in reducing the children’s blood lead levels in Syracuse, NY. Also, the reduction of the seasonal variation of children’s BLLs reflected the impacts of the local lead-based paint mitigation program. The replacement of window and door was the major cost of lead house abatement. However, soil lead was not considered a major source of lead hazard in our analysis. PMID:28182688

Interrupted time series analysis of children's blood lead levels: A case study of lead hazard control program in Syracuse, New York.

PubMed

Shao, Liyang; Zhang, Lianjun; Zhen, Zhen

2017-01-01

Children's blood lead concentrations have been closely monitored over the last two decades in the United States. The bio-monitoring surveillance data collected in local agencies reflected the local temporal trends of children's blood lead levels (BLLs). However, the analysis and modeling of the long-term time series of BLLs have rarely been reported. We attempted to quantify the long-term trends of children's BLLs in the city of Syracuse, New York and evaluate the impacts of local lead poisoning prevention programs and Lead Hazard Control Program on reducing the children's BLLs. We applied interrupted time series analysis on the monthly time series of BLLs surveillance data and used ARMA (autoregressive and moving average) models to measure the average children's blood lead level shift and detect the seasonal pattern change. Our results showed that there were three intervention stages over the past 20 years to reduce children's BLLs in the city of Syracuse, NY. The average of children's BLLs was significantly decreased after the interventions, declining from 8.77μg/dL to 3.94μg/dL during1992 to 2011. The seasonal variation diminished over the past decade, but more short term influences were in the variation. The lead hazard control treatment intervention proved effective in reducing the children's blood lead levels in Syracuse, NY. Also, the reduction of the seasonal variation of children's BLLs reflected the impacts of the local lead-based paint mitigation program. The replacement of window and door was the major cost of lead house abatement. However, soil lead was not considered a major source of lead hazard in our analysis.

Association between air pollution and coronary artery calcification within six metropolitan areas in the USA (the Multi-Ethnic Study of Atherosclerosis and Air Pollution): a longitudinal cohort study

PubMed Central

Kaufman, Joel D; Adar, Sara D; Barr, R Graham; Budoff, Matthew; Burke, Gregory L; Curl, Cynthia L; Daviglus, Martha L; Roux, Ana V Diez; Gassett, Amanda J; Jacobs, David R; Kronmal, Richard; Larson, Timothy V; Navas-Acien, Ana; Olives, Casey; Sampson, Paul D; Sheppard, Lianne; Siscovick, David S; Stein, James H; Szpiro, Adam A; Watson, Karol E

2016-01-01

Summary Background Long-term exposure to fine particulate matter less than 2·5 μm in diameter (PM2·5) and traffic-related air pollutant concentrations are associated with cardiovascular risk. The disease process underlying these associations remains uncertain. We aim to assess association between long-term exposure to ambient air pollution and progression of coronary artery calcium and common carotid artery intima-media thickness. Methods In this prospective 10-year cohort study, we repeatedly measured coronary artery calcium by CT in 6795 participants aged 45–84 years enrolled in the Multi-Ethnic Study of Atherosclerosis and Air Pollution (MESA Air) in six metropolitan areas in the USA. Repeated scans were done for nearly all participants between 2002 and 2005, for a subset of participants between 2005 and 2007, and for half of all participants between 2010 and 2012. Common carotid artery intima-media thickness was measured by ultrasound in all participants at baseline and in 2010–12 for 3459 participants. Residence-specific spatio-temporal pollution concentration models, incorporating community-specific measurements, agency monitoring data, and geographical predictors, estimated concentrations of PM2·5 and nitrogen oxides (NOX) between 1999 and 2012. The primary aim was to examine the association between both progression of coronary artery calcium and mean carotid artery intima-media thickness and long-term exposure to ambient air pollutant concentrations (PM2·5, NOX, and black carbon) between examinations and within the six metropolitan areas, adjusting for baseline age, sex, ethnicity, socioeconomic characteristics, cardiovascular risk factors, site, and CT scanner technology. Findings In this population, coronary calcium increased on average by 24 Agatston units per year (SD 58), and intima-media thickness by 12 μm per year (10), before adjusting for risk factors or air pollutant exposures. Participant-specific pollutant concentrations averaged over the years 2000–10 ranged from 9·2–22·6 μg PM2·5/m3 and 7·2–139·2 parts per billion (ppb) NOX. For each 5 μg PM2·5/m3 increase, coronary calcium progressed by 4·1 Agatston units per year (95% CI 1·4–6·8) and for each 40 ppb NOX coronary calcium progressed by 4·8 Agatston units per year (0·9–8·7). Pollutant exposures were not associated with intima-media thickness change. The estimate for the effect of a 5 μg/m3 higher long-term exposure to PM2·5 in intima-media thickness was −0·9 μm per year (95% CI −3·0 to 1·3). For 40 ppb higher NOX, the estimate was 0·2 μm per year (−1·9 to 2·4). Interpretation Increased concentrations of PM2·5 and traffc-related air pollution within metropolitan areas, in ranges commonly encountered worldwide, are associated with progression in coronary calcification, consistent with acceleration of atherosclerosis. This study supports the case for global efforts of pollution reduction in prevention of cardiovascular diseases. Funding US Environmental Protection Agency and US National Institutes of Health. PMID:27233746

Neonicotinoid contamination of global surface waters and associated risk to aquatic invertebrates: a review.

PubMed

Morrissey, Christy A; Mineau, Pierre; Devries, James H; Sanchez-Bayo, Francisco; Liess, Matthias; Cavallaro, Michael C; Liber, Karsten

2015-01-01

Neonicotinoids, broad-spectrum systemic insecticides, are the fastest growing class of insecticides worldwide and are now registered for use on hundreds of field crops in over 120 different countries. The environmental profile of this class of pesticides indicate that they are persistent, have high leaching and runoff potential, and are highly toxic to a wide range of invertebrates. Therefore, neonicotinoids represent a significant risk to surface waters and the diverse aquatic and terrestrial fauna that these ecosystems support. This review synthesizes the current state of knowledge on the reported concentrations of neonicotinoids in surface waters from 29 studies in 9 countries world-wide in tandem with published data on their acute and chronic toxicity to 49 species of aquatic insects and crustaceans spanning 12 invertebrate orders. Strong evidence exists that water-borne neonicotinoid exposures are frequent, long-term and at levels (geometric means=0.13μg/L (averages) and 0.63μg/L (maxima)) which commonly exceed several existing water quality guidelines. Imidacloprid is by far the most widely studied neonicotinoid (66% of the 214 toxicity tests reviewed) with differences in sensitivity among aquatic invertebrate species ranging several orders of magnitude; other neonicotinoids display analogous modes of action and similar toxicities, although comparative data are limited. Of the species evaluated, insects belonging to the orders Ephemeroptera, Trichoptera and Diptera appear to be the most sensitive, while those of Crustacea (although not universally so) are less sensitive. In particular, the standard test species Daphnia magna appears to be very tolerant, with 24-96hour LC50 values exceeding 100,000μg/L (geometric mean>44,000μg/L), which is at least 2-3 orders of magnitude higher than the geometric mean of all other invertebrate species tested. Overall, neonicotinoids can exert adverse effects on survival, growth, emergence, mobility, and behavior of many sensitive aquatic invertebrate taxa at concentrations at or below 1μg/L under acute exposure and 0.1μg/L for chronic exposure. Using probabilistic approaches (species sensitivity distributions), we recommend here that ecological thresholds for neonicotinoid water concentrations need to be below 0.2μg/L (short-term acute) or 0.035μg/L (long-term chronic) to avoid lasting effects on aquatic invertebrate communities. The application of safety factors may still be warranted considering potential issues of slow recovery, additive or synergistic effects and multiple stressors that can occur in the field. Our analysis revealed that 81% (22/27) and 74% (14/19) of global surface water studies reporting maximum and average individual neonicotinoid concentrations respectively, exceeded these thresholds of 0.2 and 0.035μg/L. Therefore, it appears that environmentally relevant concentrations of neonicotinoids in surface waters worldwide are well within the range where both short- and long-term impacts on aquatic invertebrate species are possible over broad spatial scales. Copyright © 2014 Elsevier Ltd. All rights reserved.

Superior long-term stability of a glucose biosensor based on inserted barrel plating gold electrodes.

PubMed

Hsu, Cheng-Teng; Hsiao, Hung-Chan; Fang, Mei-Yen; Zen, Jyh-Myng

2009-10-15

Disposable one shot usage blood glucose strips are routinely used in the diagnosis and management of diabetes mellitus and their performance can vary greatly. In this paper we critically evaluated the long-term stability of glucose strips made of barrel plating gold electrodes. Compared to other glucose biosensing platforms of vapor deposited palladium and screen printed carbon electrodes, the proposed glucose biosensor was found to show the best stability among the three biosensing platforms in thermal acceleration experiments at 40 degrees C for 6 months with an average bias of 3.4% at glucose concentrations of 5-20 mM. The precision test of this barrel plating gold glucose biosensor also showed the best performance (coefficients of variation in the range of 1.4-2.4%) in thermal acceleration experiments at 40 degrees C, 50 degrees C and 70 degrees C for 27 days. Error grid analysis revealed that all measurements fell in zone A and zone B. Regression analysis showed no significant difference between the proposed biosensor and the reference method at 99% confidence level. The amperometric glucose biosensor fabricated by inserting two barrel plating gold electrodes onto an injection-molding plastic base followed by immobilizing with a bio-reagent layer and membrane was very impressive with a long-term stability up to 2.5 years at 25 degrees C. Overall, these results indicated that the glucose oxidase/barrel plating gold biosensing platform is ideal for long-term accurate glycemic control.

High feather mercury concentrations in the wandering albatross are related to sex, breeding status and trophic ecology with no demographic consequences

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bustamante, Paco, E-mail: pbustama@univ-lr.fr; Carravieri, Alice; Centre d’Etudes Biologiques de Chizé

Hg can affect physiology of seabirds and ultimately their demography, particularly if they are top consumers. In the present study, body feathers of >200 wandering albatrosses from Possession Island in the Crozet archipelago were used to explore the potential demographic effects of the long-term exposure to Hg on an apex predator. Variations of Hg with sex, age class, foraging habitat (inferred from δ{sup 13}C values), and feeding habits (inferred from δ{sup 15}N values) were examined as well as the influence of Hg on current breeding output, long-term fecundity and survival. Wandering albatrosses displayed among the highest Hg feather concentrations reportedmore » for seabirds, ranging from 5.9 to 95 µg g{sup −1}, as a consequence of their high trophic position (δ{sup 15}N values). These concentrations fall within the same range of those of other wandering albatross populations from subantarctic sites, suggesting that this species has similar exposure to Hg all around the Southern Ocean. In both immature and adult albatrosses, females had higher Hg concentrations than males (28 vs. 20 µg g{sup −1} dw on average, respectively), probably as a consequence of females foraging at lower latitudes than males (δ{sup 13}C values). Hg concentrations were higher in immature than in adult birds, and they remained fairly constant across a wide range of ages in adults. Such high levels in immature individuals question (i) the frequency of moult in young birds, (ii) the efficiency of Hg detoxification processes in immatures compared to adults, and (iii) importantly the potential detrimental effects of Hg in early life. Despite very high Hg concentrations in their feathers, neither effects on adults' breeding probability, hatching failure and fledgling failure, nor on adults' survival rate were detected, suggesting that long-term bioaccumulated Hg was not under a chemical form leading to deleterious effects on reproductive parameters in adult individuals. - Highlights: • Immature albatrosses had higher feather Hg concentrations than adults. • Foraging habitat influenced Hg bioaccumulation as a result of male and female segregation. • No carry-over effects were detected on reproductive parameters.« less

Mortality Associations with Long-Term Exposure to Outdoor Air Pollution in a National English Cohort

PubMed Central

Carey, Iain M.; Kent, Andrew J.; van Staa, Tjeerd; Cook, Derek G.; Anderson, H. Ross

2013-01-01

Rationale: Cohort evidence linking long-term exposure to outdoor particulate air pollution and mortality has come largely from the United States. There is relatively little evidence from nationally representative cohorts in other countries. Objectives: To investigate the relationship between long-term exposure to a range of pollutants and causes of death in a national English cohort. Methods: A total of 835,607 patients aged 40–89 years registered with 205 general practices were followed from 2003–2007. Annual average concentrations in 2002 for particulate matter with a median aerodynamic diameter less than 10 (PM10) and less than 2.5 μm (PM2.5), nitrogen dioxide (NO2), ozone, and sulfur dioxide (SO2) at 1 km2 resolution, estimated from emission-based models, were linked to residential postcode. Deaths (n = 83,103) were ascertained from linkage to death certificates, and hazard ratios (HRs) for all- and cause-specific mortality for pollutants were estimated for interquartile pollutant changes from Cox models adjusting for age, sex, smoking, body mass index, and area-level socioeconomic status markers. Measurements and Main Results: Residential concentrations of all pollutants except ozone were positively associated with all-cause mortality (HR, 1.02, 1.03, and 1.04 for PM2.5, NO2, and SO2, respectively). Associations for PM2.5, NO2, and SO2 were larger for respiratory deaths (HR, 1.09 each) and lung cancer (HR, 1.02, 1.06, and 1.05) but nearer unity for cardiovascular deaths (1.00, 1.00, and 1.04). Conclusions: These results strengthen the evidence linking long-term ambient air pollution exposure to increased all-cause mortality. However, the stronger associations with respiratory mortality are not consistent with most US studies in which associations with cardiovascular causes of death tend to predominate. PMID:23590261

[Attention therapy for children - long-term affects of the ATTENTIONER].

PubMed

Jacobs, Claus; Petermann, Franz

2008-11-01

A high percentage of children are affected by attention deficit disorders. For a large proportion the cardinal symptom is inattention; in particular, deficits in selective attention prevail. The ATTENTIONER offers an effective training method for the treatment of selective attention deficit. In 2007, long-term effects of therapy were already reported by Jacobs and Petermann, who examined children ten weeks after therapy on average. In the current study three measurements were conducted: pre-intervention, post-intervention, and at follow-up ten to 76 months after post-intervention. Significant long-term effects on measures of selective attention were observed. At follow-up the majority of patients achieved average results which were not clinically relevant. For most children stable therapy effects can be achieved with the ATTENTIONER.

Changes in Olsen Phosphorus Concentration and Its Response to Phosphorus Balance in Black Soils under Different Long-Term Fertilization Patterns

PubMed Central

Zhan, Xiaoying; Zhang, Li; Zhou, Baoku; Zhu, Ping; Zhang, Shuxiang; Xu, Minggang

2015-01-01

The Olsen phosphorus (P) concentration of a soil is a key index that can be used to evaluate the P supply capacity of the soil and to estimate the optimal P fertilization rate. A study of the relationship between the soil Olsen P concentration and the P balance (P input minus P output) and their variations among different fertilization patterns will help to provide useful information for proper management of P fertilization. In this paper, the two investigated long-term experiments were established on black soils in the northeast region of China. Six fertilization treatments were selected: (1) unfertilized (CK); (2) nitrogen only (N); (3) nitrogen and potassium (NK); (4) nitrogen and phosphorus (NP); (5) nitrogen, phosphorus, and potassium (NPK); and (6) nitrogen, phosphorus, potassium and manure (NPKM). The results showed that the average Olsen P concentrations in the black soils at Gongzhuling and Harbin (16- and 31-year study periods, respectively), decreased by 0.49 and 0.56 mg kg-1 a-1, respectively, without P addition and increased by 3.17 and 1.78 mg kg-1 a-1, respectively, with P fertilization. The changes in soil Olsen P concentrations were significantly (P<0.05) correlated with the P balances at both sites except for the NP and NPK treatments at Gongzhuling. Under an average deficit of 100 kg ha-1 P, the soil Olsen P concentration at both sites decreased by 1.36~3.35 mg kg-1 in the treatments without P addition and increased by 4.80~16.04 mg kg-1 in the treatments with 100 kg ha-1 of P accumulation. In addition, the changes in Olsen P concentrations in the soil with 100 kg ha-1of P balance were significantly correlated with the P activation coefficient (PAC, percentage of Olsen P to total P, r=0.99, P<0.01) and soil organic matter content (r=0.91, P<0.01). A low pH was related to large changes of Olsen P by 1 kg ha-1 of P balance. These results indicated that soil organic matter and pH have important effects on the change in soil Olsen P by 1 kg ha-1 of P balance. PMID:26177293

Changes in Olsen Phosphorus Concentration and Its Response to Phosphorus Balance in Black Soils under Different Long-Term Fertilization Patterns.

PubMed

Zhan, Xiaoying; Zhang, Li; Zhou, Baoku; Zhu, Ping; Zhang, Shuxiang; Xu, Minggang

2015-01-01

The Olsen phosphorus (P) concentration of a soil is a key index that can be used to evaluate the P supply capacity of the soil and to estimate the optimal P fertilization rate. A study of the relationship between the soil Olsen P concentration and the P balance (P input minus P output) and their variations among different fertilization patterns will help to provide useful information for proper management of P fertilization. In this paper, the two investigated long-term experiments were established on black soils in the northeast region of China. Six fertilization treatments were selected: (1) unfertilized (CK); (2) nitrogen only (N); (3) nitrogen and potassium (NK); (4) nitrogen and phosphorus (NP); (5) nitrogen, phosphorus, and potassium (NPK); and (6) nitrogen, phosphorus, potassium and manure (NPKM). The results showed that the average Olsen P concentrations in the black soils at Gongzhuling and Harbin (16- and 31-year study periods, respectively), decreased by 0.49 and 0.56 mg kg-1 a-1, respectively, without P addition and increased by 3.17 and 1.78 mg kg-1 a-1, respectively, with P fertilization. The changes in soil Olsen P concentrations were significantly (P<0.05) correlated with the P balances at both sites except for the NP and NPK treatments at Gongzhuling. Under an average deficit of 100 kg ha-1 P, the soil Olsen P concentration at both sites decreased by 1.36~3.35 mg kg-1 in the treatments without P addition and increased by 4.80~16.04 mg kg-1 in the treatments with 100 kg ha-1 of P accumulation. In addition, the changes in Olsen P concentrations in the soil with 100 kg ha-1of P balance were significantly correlated with the P activation coefficient (PAC, percentage of Olsen P to total P, r=0.99, P<0.01) and soil organic matter content (r=0.91, P<0.01). A low pH was related to large changes of Olsen P by 1 kg ha-1 of P balance. These results indicated that soil organic matter and pH have important effects on the change in soil Olsen P by 1 kg ha-1 of P balance.

Lung deposited surface area concentrations in a street canyon

NASA Astrophysics Data System (ADS)

Kuuluvainen, Heino; Hietikko, Riina; Järvinen, Anssi; Saukko, Erkka; Irjala, Matti; Niemi, Jarkko V.; Timonen, Hilkka; Keskinen, Jorma; Rönkkö, Topi

2017-04-01

Street canyons are interesting environments with respect to the dispersion of traffic emissions and human exposure. Pedestrians may be exposed to relatively high concentrations of fine particles and the vertical dispersion affects the human exposure above the ground level in buildings. Previously, particle concentrations have been measured in street canyons at a few different heights (Marini et al., 2015). The information on the lung deposited surface area (LDSA) concentration, which is a relevant metric for the negative health effects, is very limited even at the ground level of street canyons (Kuuluvainen et al., 2016). More information especially on the vertical dispersion and the ground level concentrations is needed, for instance, for the use of urban planning and the design of ventilation systems in buildings. Measurements were carried out in a busy street canyon in Helsinki, Finland, at an urban super-site measurement station (Mäkelänkatu 50). The data included vertical concentration profiles measured in an intensive measurement campaign with a Partector (Naneos GmbH) installed into a drone, long-term measurements with an AQ Urban particle sensor (Pegasor Ltd.), and an extensive comparison measurement in the field with different devices measuring the LDSA. These devices were an AQ Urban, Partector, DiSCmini (Testo AG), NSAM (TSI Inc.), and an ELPI+ (Dekati Ltd.). In addition, continuous measurements of gas phase components, particle size distributions, and meteorology were run at the supersite. The vertical profile measurements were con-ducted in November 2016 during two days. In the measurements, the drone was flown from the ground level to an altitude of 50 or 100 m, which is clearly above the roof level of the buildings. Altogether, 48 up-and-down flights were conducted during the two days. The vertical profiles were supported by continuous measurements at the ground level on both sides of the street canyon. The long-term measurements were conducted during the year 2016. A short period of data was also analysed with respect to the emissions of individual vehicles by using a recorded video of the traffic fleet. As an example of the vertical profiles, Figure 1 shows the LDSA concentration as a function of the altitude. The data measured with a time resolution of one second is seen along with the values averaged for different altitude intervals. The effect of wind conditions and changes in the traffic fleet on the concentration profiles could be analysed. In addition to the vertical profiles, we were able to analyse the LDSA concentrations on the ground level with respect to long-term averages and rapid changes caused by different individual vehicles. This work was conducted in two different research projects. The INKA-ILMA/EAKR project was funded by Tekes, European Union, Finnish companies, Helsinki Region Environmental Authority (HSY), and cities of Tampere and Kuopio. The CITYZER project was funded by Tekes and Finnish companies. References: Marini, S., Buonanno, G., Stabile, L., Avino, P. (2015). Environ. Sci. Pollut. Res., 22 (3), 2051-2063. Kuuluvainen, H., Rönkkö, T., Järvinen, A., Saari, S., Karjalainen, P., Lähde, T., Pirjola, L., Niemi, J. V., Hillamo, R., Keskinen, J. (2016). Atmos. Environ., 136, 105-113.

A long-term stability study of Prussian blue: A quality assessment of water content and cesium binding.

PubMed

Mohammad, Adil; Yang, Yongsheng; Khan, Mansoor A; Faustino, Patrick J

2015-01-25

Prussian blue (PB) is the active pharmaceutical ingredient (API) of Radiogardase, the first approved medical countermeasure for the treatment of radiocesium poisoning in the event of a major radiological incident such as a "dirty bomb" or nuclear attack. The purpose of this study is to assess the long-term stability of Prussian blue drug products (DPs) and APIs under laboratory storage condition by monitoring the loss in water content and the in vitro cesium binding. The water content was measured by thermal gravimetric analysis (TGA). The in-vitro cesium binding study was conducted using a surrogate model to mimic gastric residence and intestinal transport. Free cesium was analyzed using a validated flame atomic emission spectroscopy (AES) method. The binding equilibrium was reached at 24h. The Langmuir isotherm was plotted to calculate the maximum binding capacity (MBC). Comparison of the same PB samples with 2003 data samples, the water content of both APIs and DPs decreased on an average by approximately 12-24%. Consequently, the MBC of cesium was decreased from 358mg/g in 2003 to 265mg/g @ pH 7.5, a decrease of approximately 26%. The binding of cesium is also pH dependent with lowest binding at pH 1.0 and maximum binding at pH 7.5. At pH 7.5, the amount of cesium bound decreased by an average value of 7.9% for APIs and 8.9% for DPs (for 600ppm initial cesium concentration). These findings of water loss, pH dependence and decrease in cesium binding are consistent with our previously published data in 2003. Over last 10 years the stored DPs and APIs of PB have lost about 20% of water which has a negative impact on the PB cesium binding, however PB still meets the FDA specification of >150mg/g at equilibrium. The study is the first quantitative assessment of the long-term stability of PB and directs that proper long-term and short-term storage of PB is required to ensure that it is safe and efficacious at the time of an emergency situation. Published by Elsevier B.V.

Speciation and isotopic exchangeability of nickel in soil solution.

PubMed

Nolan, Annette L; Ma, Yibing; Lombi, Enzo; McLaughlin, Mike J

2009-01-01

Knowledge of trace metal speciation in soil pore waters is important in addressing metal bioavailability and risk assessment of contaminated soils. In this study, free Ni(2+) activities were determined in pore waters of long-term Ni-contaminated soils using a Donnan dialysis membrane technique. The pore water free Ni(2+) concentration as a percentage of total soluble Ni ranged from 21 to 80% (average 53%), and the average amount of Ni bound to dissolved organic matter estimated by Windermere Humic Aqueous Model VI was < or = 17%. These data indicate that complexed forms of Ni can constitute a significant fraction of total Ni in solution. Windermere Humic Aqueous Model VI provided reasonable estimates of free Ni(2+) fractions in comparison to the measured fractions (R(2) = 0.83 with a slope of 1.0). Also, the isotopically exchangeable pools (E value) of soil Ni were measured by an isotope dilution technique using water extraction, with and without resin purification, and 0.1 mol L(-1) CaCl(2) extraction, and the isotopic exchangeability of Ni species in soil water extracts was investigated. The concentrations of isotopically non-exchangeable Ni in water extracts were <9% of total water soluble Ni concentrations for all soils. The resin E values expressed as a percentage of the total Ni concentrations in soil showed that the labile Ni pool ranged from 0.9 to 32.4% (average 12.4%) of total soil Ni. Therefore the labile Ni pool in these well-equilibrated contaminated soils appears to be relatively small in relation to total Ni concentrations.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, L.L.; Hooper, M.

This report summarizes the activities and results for the second testing phase (Phase 2) of an Innovative Clean Coal Technology (ICCT) demonstration of advanced tangentially fired combustion techniques for the reduction of nitrogen oxide (NOx) emissions from coal-fired boilers. All three levels of Asea Brown Boveri Combustion Engineering Service`s (ABB CE`s) Low-NO{sub x} Concentric Firing System (LNCFS) are being demonstrated during this project. The primary goal of this project is to demonstrate the NO{sub x} emissions characteristics of these technologies when operated under normal load dispatched conditions. The equipment is being tested at Gulf Power Company`s Plant Lansing Smith Unitmore » 2 in Lynn Haven, Florida. The long-term NO{sub x} emission trends were documented while the unit was operating under normal load dispatch conditions with the LNCFS Level II equipment. Fifty-five days of long-term data were collected. The data included the effects of mill patterns, unit load, mill outages, weather, fuel variability, and load swings. Test results indicated full-load (180 MW) NO{sub x} emissions of 0.39 lb/MBtu, which is about equal to the short-term test results. At 110 MW, long-term NO{sub x} emissions increased to 0.42 lb/MBtu, which are slightly higher than the short-term data. At 75 MW, NO{sub x} emissions were 0.51 lb/MBtu, which is significantly higher than the short-term data. The annual and 30-day average achievable NOx emissions were determined to be 0.41 and 0.45 lb/MBtu, respectively, for long-term testing load scenarios. NO{sub x} emissions were reduced by a maximum of 40 percent when compared to the baseline data collected in the previous phase. The long-term NO{sub x} reduction at full load (180 MW) was 37 percent while NO{sub x} reduction at low load was minimal.« less

Psychosocial Outcomes in Long-Term Cochlear Implant Users.

PubMed

Castellanos, Irina; Kronenberger, William G; Pisoni, David B

The objectives of this study were to investigate psychosocial outcomes in a sample of prelingually deaf, early-implanted children, adolescents, and young adults who are long-term cochlear implant (CI) users and to examine the extent to which language and executive functioning predict psychosocial outcomes. Psychosocial outcomes were measured using two well-validated, parent-completed checklists: the Behavior Assessment System for Children and the Conduct Hyperactive Attention Problem Oppositional Symptom. Neurocognitive skills were measured using gold standard, performance-based assessments of language and executive functioning. CI users were at greater risk for clinically significant deficits in areas related to attention, oppositional behavior, hyperactivity-impulsivity, and social-adaptive skills compared with their normal-hearing peers, although the majority of CI users scored within average ranges relative to Behavior Assessment System for Children norms. Regression analyses revealed that language, visual-spatial working memory, and inhibition-concentration skills predicted psychosocial outcomes. Findings suggest that underlying delays and deficits in language and executive functioning may place some CI users at a risk for difficulties in psychosocial adjustment.

Identification of rice cultivar with exclusive characteristic to Cd using a field-polluted soil and its foreground application.

PubMed

Zhan, Jie; Wei, Shuhe; Niu, Rongcheng; Li, Yunmeng; Wang, Shanshan; Zhu, Jiangong

2013-04-01

Using low-accumulative plant, especially excluder crop, to safely produce food is one of the very important technologies of phytoremediation, which is practical to safe production and long-term remediation of heavy metal-contaminated soil. A pot experiment using field cadmium (Cd)-contaminated soil (Cd concentration was 0.75 mg kg(-1)) was conducted to compare Cd accumulation differences among 39 normal rice cultivars (Japonica) in Shenyang region of China for food safety and high grain yield aim. The results showed that brown grain Cd concentration in 12 rice cultivars of a total of 39 tested cultivars was lower than 0.2 mg kg(-1) (Agricultural Trade Standard of Nonpollution Food for Rice of China, NY 5115-2008). In these 12 cultivars, Cd enrichment factors (Cd concentration ratio in shoot to that in soil) of nine cultivars were lower than 1. Likewise, Cd translocation factors (Cd concentration ratio in shoot to that in root) of eight cultivars were lower than the 0.28 average. Furthermore, grain yield per pot of seven cultivars were higher than the average 18.4 g pot(-1). Four cultivars, i.e., Shendao 5, Tianfu 1, Fuhe 90, and Yanfeng 47 showed Cd-exclusive characteristic and better foreground application.

Long-term trends and weekday-to-weekend differences in ozone, its precursors, and other secondary pollutants in Atlanta, Georgia

NASA Astrophysics Data System (ADS)

Pollack, I. B.; Ryerson, T. B.; Baumann, K.; Edgerton, E. S.; De Gouw, J. A.; Gilman, J.; Graus, M.; Holloway, J.; Lerner, B. M.; Neuman, J. A.; Roberts, J. M.; Veres, P. R.; Warneke, C.; Trainer, M.; Parrish, D. D.

2013-12-01

In an environment rich in biogenic volatile organic compounds (VOCs), decreasing concentrations of ozone (-1.3 % yr-1) and other secondary pollutants (-8.2 % yr-1 for nitric acid, HNO3; and -7.9 % yr-1 for peroxyacetyl nitrate, PAN) in Atlanta, Georgia over the past fifteen years are primarily attributed to decreases in local emissions of nitrogen oxides (NOx=NO+NO2). Large reductions in abundances of NOx in the Southeast U.S. over the years (-8.0 % yr-1 for total reactive nitrogen, NOy) are the direct result of control strategies implemented to reduced emissions from electric-power generation plants and on-road motor vehicles. Here, we compile an extensive historical data set of trace gas measurements spanning fifteen years between 1998 and 2013 from a surface monitoring network site in downtown Atlanta (i.e. the SEARCH network Jefferson Street site) and research aircraft (e.g. the 2013 Southeast Atmosphere Study and 1999 Southern Oxidants Study aboard the NOAA P-3 aircraft). With this data set we confirm and extend long-term trends and weekday-to-weekend differences in ozone, its precursors, and other secondary pollutants during summertime in Atlanta. Long-term changes in abundances and enhancement ratios of secondary oxidation products indicate changes in pollutant formation chemistry in Atlanta resulting from the significant decrease in NOx precursor emissions over the past fifteen years. The most noteworthy changes include: 1) an increase in enhancement ratios of odd oxygen (Ox=O3+NO2) to (PAN+HNO3) of +5.5 % yr-1 indicating an increase in ozone production efficiency by a factor of 2 over the fifteen year period, 2) no significant change in the fraction of oxidized NOx out of NOy over time indicating little change in the extent of photochemical processing of the NOx emissions, and 3) a flip in observed ozone concentrations from higher average ozone on weekends to higher average ozone on weekdays after 2004. The observations for Atlanta will also be contrasted with results from a similar analysis of California's Los Angeles air basin, a region with considerably different precursor abundances and emissions, control strategies, transport, and meteorology.

Long-term Hearing Preservation After Resection of Vestibular Schwannoma: A Systematic Review and Meta-analysis.

PubMed

Ahsan, Syed F; Huq, Farhan; Seidman, Michael; Taylor, Andrew

2017-12-01

The objective is to perform a systematic review and meta-analysis of the literature on the long-term results of hearing preservation after vestibular schwannoma resection. Ovid/Medline, PubMed, Embase, and the Cochrane library from January 1980 to January 2015. Inclusion criteria: age ≥18 years, minimum 10 patients in the treatment group, hearing preserving microsurgery, no previous radiation treatment, serviceable hearing at immediate postop follow-up, hearing outcomes reported using Gardner Robinson or the American Academy of Otolaryngology-Head and Neck Surgeons hearing grading scales, and average follow-up of 5 years. Preoperative, immediate postoperative, and last follow-up audiograms were required. Exclusion criteria included neurofibromatosis type 2 patients and surgery for salvage therapy or decompression. Quality evaluated using Methodological Index for Non-Randomized Studies. Meta-analysis was performed using R v3.2.2, Metafor package v 1.9-7. Cohen's D was used to determine effect size. Ten reports had at least 5-year follow-up and used standardized hearing grading scales. The systematic review found that if hearing was preserved at Class A or B at early postop visit, the chance of preserving hearing at 5 years was excellent. Those who maintained speech discrimination score ≥ 89% at the early postoperative follow-up had better long-term hearing preservation. The meta-analysis reveals that only preoperative and postoperative pure-tone average was associated with long-term hearing preservation. Long-term (>5 yr) hearing durability rates are generally very good. Most studies do not report patient and tumor characteristics, therefore precluding combining studies for meta-analysis. Only preoperative and postoperative postoperative pure-tone average was associated with long-term hearing durability.

Water Budget of East Maui, Hawaii

USGS Publications Warehouse

Shade, Patricia J.

1999-01-01

Ground-water recharge is estimated from six monthly water budgets calculated using long-term average rainfall and streamflow data, estimated pan-evaporation and fog-drip data, and soil characteristics. The water-budget components are defined seasonally, through the use of monthly data, and spatially by broad climatic and geohydrologic areas, through the use of a geographic information system model. The long-term average water budget for east Maui was estimated for natural land-use conditions. The average rainfall, fog-drip, runoff, evapotranspiration, and ground-water recharge volumes for the east Maui study area are 2,246 Mgal/d, 323 Mgal/d, 771 Mgal/d, 735 Mgal/d, and 1,064 Mgal/d, respectively.

Long-term exposure to air pollution is associated with survival following acute coronary syndrome

PubMed Central

Tonne, Cathryn; Wilkinson, Paul

2013-01-01

Aims The aim of this study was to determine (i) whether long-term exposure to air pollution was associated with all-cause mortality using the Myocardial Ischaemia National Audit Project (MINAP) data for England and Wales, and (ii) the extent to which exposure to air pollution contributed to socioeconomic inequalities in prognosis. Methods and results Records of patients admitted to hospital with acute coronary syndrome (ACS) in MINAP collected under the National Institute for Cardiovascular Outcomes Research were linked to modelled annual average air pollution concentrations for 2004–10. Hazard ratios for mortality starting 28 days after admission were estimated using Cox proportional hazards models. Among the 154 204 patients included in the cohort, the average follow-up was 3.7 years and there were 39 863 deaths. Mortality rates were higher for individuals exposed to higher levels of particles with a diameter of ≤2.5 µm (PM2.5; PM, particulate matter): the fully adjusted hazard ratio for a 10 µg/m3 increase in PM2.5 was 1.20 (95% CI 1.04–1.38). No associations were observed for larger particles or oxides of nitrogen. Air pollution explained socioeconomic inequalities in survival to only a small extent. Conclusion Mortality from all causes was higher among individuals with greater exposure to PM2.5 in survivors of hospital admission for ACS in England and Wales. Despite higher exposure to PM2.5 among those from more deprived areas, such exposure was a minor contribution to the socioeconomic inequalities in prognosis following ACS. Our findings add to the evidence of mortality associated with long-term exposure to fine particles. PMID:23423735

Long-term exposure to ambient particulate matter (PM2.5) is associated with platelet counts in adults.

PubMed

Zhang, Zilong; Chan, Ta-Chien; Guo, Cui; Chang, Ly-Yun; Lin, Changqing; Chuang, Yuan Chieh; Jiang, Wun Kai; Ho, Kin Fai; Tam, Tony; Woo, Kam S; Lau, Alexis K H; Lao, Xiang Qian

2018-05-09

The prothrombotic effects of particulate matter (PM) may underlie the association of air pollution with increased risks of cardiovascular disease. This study aimed to investigate the association between long-term exposure to PM with an aerodynamic diameter ≤2.5 μm (PM 2.5 ) and platelet counts, a marker of coagulation profiles. The study participants were from a cohort consisting of 362,396 Taiwanese adults who participated in a standard medical examination program between 2001 and 2014. Platelet counts were measured through Complete Blood Count tests. A satellite-based spatio-temporal model was used to estimate 2-year average ambient PM 2.5 concentration at each participant's address. Mixed-effects linear regression models were used to investigate the association between PM 2.5 exposure and platelet counts. This analysis included 175,959 men with 396,248 observations and 186,437 women with 397,877 observations. Every 10-μg/m 3 increment in the 2-year average PM 2.5 was associated with increases of 0.42% (95% CI: 0.38%, 0.47%) and 0.49% (95% CI: 0.44%, 0.54%) in platelet counts in men and women, respectively. A series of sensitivity analyses, including an analysis in participants free of cardiometabolic disorders, confirmed the robustness of the observed associations. Baseline data analyses showed that every 10-μg/m 3 increment in PM 2.5 was associated with higher risk of 17% and 14% of having elevated platelet counts (≥90th percentile) in men and women, respectively. Long-term exposure to PM 2.5 appears to be associated with increased platelet counts, indicating potential adverse effects on blood coagulability. Copyright © 2018 Elsevier Ltd. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Serne, R. Jeffrey; Westsik, Joseph H.; Williams, Benjamin D.

This report describes the results from long-term laboratory leach tests performed at Pacific Northwest National Laboratory (PNNL) for Washington River Protection Solutions (WRPS) to evaluate the release of key constituents from monoliths of Cast Stone prepared with four simulated low-activity waste (LAW) liquid waste streams. Specific objectives of the Cast Stone long-term leach tests described in this report focused on four activities: 1. Extending the leaching times for selected ongoing EPA-1315 tests on monoliths made with LAW simulants beyond the conventional 63-day time period up to 609 days reported herein (with some tests continuing that will be documented later) inmore » an effort to evaluate long-term leaching properties of Cast Stone to support future performance assessment activities. 2. Starting new EPA-1315 leach tests on archived Cast Stone monoliths made with four LAW simulants using two leachants (deionized water [DIW] and simulated Hanford Integrated Disposal Facility (IDF) Site vadose zone pore water [VZP]). 3. Evaluating the impacts of varying the iodide loading (starting iodide concentrations) in one LAW simulant (7.8 M Na Hanford Tank Waste Operations Simulator (HTWOS) Average) by manufacturing new Cast Stone monoliths and repeating the EPA-1315 leach tests using DIW and the VZP leachants. 4. Evaluating the impacts of using a non-pertechnetate form of Tc that is present in some Hanford tanks. In this activity one LAW simulant (7.8 M Na HTWOS Average) was spiked with a Tc(I)-tricarbonyl gluconate species and then solidified into Cast Stone monoliths. Cured monoliths were leached using the EPA-1315 leach protocol with DIW and VZP. The leach results for the Tc-Gluconate Cast Stone monoliths were compared to Cast Stone monoliths pertechnetate.« less

Long term observations of PM2.5-associated PAHs: Comparisons between normal and episode days

NASA Astrophysics Data System (ADS)

Wang, Jia; Li, Xiao; Jiang, Nan; Zhang, Wenkai; Zhang, Ruiqin; Tang, Xiaoyan

2015-03-01

The pollution characteristic of fine particular matter (PM2.5) and associated polycyclic aromatic hydrocarbons (PAHs) are currently drawing a great deal of interest because of their influence on environment and health. In this study, PM2.5 was collected from 2011 to 2013 (n = 188) in a suburban area of Zhengzhou, China. 16-PAHs were analyzed to determine the concentration, seasonal variation and potential sources during normal days and episode events. The total mass of 16 PAHs and PM2.5 were in the range of 7-961 ng m-3 and 55-697 μg m-3, with a 3-year average of 174 ng m-3 and 194 μg m-3 respectively. Winter is most polluted for both PM2.5 and PAHs. Average PAH and PM2.5 concentrations during three episode events are 454 ng m-3 and 453 μg m-3, respectively, much higher than values during normal days (299 ng m-3 and 180 μg m-3, respectively). Ratios of Σ16PAH/PM2.5 varied with seasons and concentrations of PM2.5, but showed a negative correlation with PM2.5 concentrations during episode events. The dominant components of PAHs are Benzo[b]fluoranthene, Chrysene, Fluoranthene, and Benzo[k]fluoranthene, Benz[a]anthracene, Pyrene, Indeno(1,2,3-cd)pyrene and their total concentrations vary from 27 to 342 ng m-3, accounting for 58-82% (average = 73%) of 16 PAHs. The Benzo[a]pyrene (Bap) concentration obtained was 9.4 ng m-3 (3-year average), exceeding nearly one order of magnitude of ambient air BaP standard (annual average: 1.0 ng m-3) in China. Diagnose ratios and Positive Matrix Factorization results show that coal combustion, vehicles, coking plant, and biomass burning are main sources for PAHs in this area. The high concentrations of PM2.5 and PAHs, especially during episode events, reflected a potential health problem for nearby public and the necessity of air pollution control for both stationary and mobile sources.

Historical and projected climate in the Northern Rockies Region [Chapter 3

Treesearch

Linda A. Joyce; Marian Talbert; Darrin Sharp; Jeffrey Morisette; John Stevenson

2018-01-01

Climate influences the ecosystem services we obtain from forest and rangelands. Climate is described by the long-term characteristics of precipitation, temperature, wind, snowfall, and other measures of weather that occur over a long period in a particular place, and is typically expressed as long-term average conditions. Resource management practices are implemented...

Long-Term Planetary Habitability and the Carbonate-Silicate Cycle

NASA Astrophysics Data System (ADS)

Rushby, Andrew J.; Johnson, Martin; Mills, Benjamin J. W.; Watson, Andrew J.; Claire, Mark W.

2018-05-01

The potential habitability of an exoplanet is traditionally assessed by determining if its orbit falls within the circumstellar `habitable zone' of its star, defined as the distance at which water could be liquid on the surface of a planet (Kopparapu et al., 2013). Traditionally, these limits are determined by radiative-convective climate models, which are used to predict surface temperatures at user-specified levels of greenhouse gases. This approach ignores the vital question of the (bio)geochemical plausibility of the proposed chemical abundances. Carbon dioxide is the most important greenhouse gas in Earth's atmosphere in terms of regulating planetary temperature, with the long term concentration controlled by the balance between volcanic outgassing and the sequestration of CO2 via chemical weathering and sedimentation, as modulated by ocean chemistry, circulation and biological (microbial) productivity. We develop a model incorporating key aspects of Earth's short and long-term biogeochemical carbon cycle to explore the potential changes in the CO2 greenhouse due to variance in planet size and stellar insolation. We find that proposed changes in global topography, tectonics, and the hydrological cycle on larger planets results in proportionally greater surface temperatures for a given incident flux. For planets between 0.5 to 2 R_earth the effect of these changes results in average global surface temperature deviations of up to 20 K, which suggests that these relationships must be considered in future studies of planetary habitability.

Patterns and predictability in the intra-annual organic carbon variability across the boreal and hemiboreal landscape

USGS Publications Warehouse

Hytteborn, Julia K.; Temnerud, Johan; Alexander, Richard B.; Boyer, Elizabeth W.; Futter, Martyn N.; Fröberg, Mats; Dahné, Joel; Bishop, Kevin H.

2015-01-01

Factors affecting total organic carbon (TOC) concentrations in 215 watercourses across Sweden were investigated using parameter parsimonious regression approaches to explain spatial and temporal variabilities of the TOC water quality responses. We systematically quantified the effects of discharge, seasonality, and long-term trend as factors controlling intra-annual (among year) and inter-annual (within year) variabilities of TOC by evaluating the spatial variability in model coefficients and catchment characteristics (e.g. land cover, retention time, soil type).Catchment area (0.18–47,000 km2) and land cover types (forests, agriculture and alpine terrain) are typical for the boreal and hemiboreal zones across Fennoscandia. Watercourses had at least 6 years of monthly water quality observations between 1990 and 2010. Statistically significant models (p < 0.05) describing variation of TOC in streamflow were identified in 209 of 215 watercourses with a mean Nash-Sutcliffe efficiency index of 0.44. Increasing long-term trends were observed in 149 (70%) of the watercourses, and intra-annual variation in TOC far exceeded inter-annual variation. The average influences of the discharge and seasonality terms on intra-annual variations in daily TOC concentration were 1.4 and 1.3 mg l− 1 (13 and 12% of the mean annual TOC), respectively. The average increase in TOC was 0.17 mg l− 1 year− 1 (1.6% year− 1).Multivariate regression with over 90 different catchment characteristics explained 21% of the spatial variation in the linear trend coefficient, less than 20% of the variation in the discharge coefficient and 73% of the spatial variation in mean TOC. Specific discharge, water residence time, the variance of daily precipitation, and lake area, explained 45% of the spatial variation in the amplitude of the TOC seasonality.Because the main drivers of temporal variability in TOC are seasonality and discharge, first-order estimates of the influences of climatic variability and change on TOC concentration should be predictable if the studied catchments continue to respond similarly.

Using Computers To Accommodate Learning Disabled Students in Mathematics Classes.

ERIC Educational Resources Information Center

Rapp, Rhonda H.; Gittinger, Dennis J.

A person with a learning disability usually has average or above average intelligence, but has difficulty taking in, remembering, or expressing information. Learning disabilities can involve visual processing speed, short-term memory processing, fluid reasoning, and long-term memory retrieval. These disorders are intrinsic to the individual and…

A portable data-logging system for industrial hygiene personal chlorine monitoring.

PubMed

Langhorst, M L; Illes, S P

1986-02-01

The combination of suitable portable sensors or instruments with small microprocessor-based data-logger units has made it possible to obtain detailed monitoring data for many health and environmental applications. Following data acquisition in field use, the logged data may be transferred to a desk-top personal computer for complete flexibility in manipulation of data and formating of results. A system has been assembled from commercial components and demonstrated for chlorine personal monitoring applications. The system consists of personal chlorine sensors, a Metrosonics data-logger and reader unit, and an Apple II Plus personal computer. The computer software was developed to handle sensor calibration, data evaluation and reduction, report formating and long-term storage of raw data on a disk. This system makes it possible to generate time-concentration profiles, evaluate dose above a threshold, quantitate short-term excursions and summarize time-weighted average (TWA) results. Field data from plant trials demonstrated feasibility of use, ruggedness and reliability. No significant differences were found between the time-weighted average chlorine concentrations determined by the sensor/logger system and two other methods: the sulfamic acid bubbler reference method and the 3M Poroplastic diffusional dosimeter. The sensor/data-logger system, however, provided far more information than the other two methods in terms of peak excursions, TWAs and exposure doses. For industrial hygiene applications, the system allows better definition of employee exposures, particularly for chemicals with acute as well as chronic health effects.(ABSTRACT TRUNCATED AT 250 WORDS)

LONG TERM HYDROLOGICAL IMPACT ASSESSMENT (LTHIA)

EPA Science Inventory

LTHIA is a universal Urban Sprawl analysis tool that is available to all at no charge through the Internet. It estimates impacts on runoff, recharge and nonpoint source pollution resulting from past or proposed land use changes. It gives long-term average annual runoff for a lan...

Quantification of hair cortisol concentration in common marmosets (Callithrix jacchus) and tufted capuchins (Cebus apella).

PubMed

Phillips, Kimberley A; Tukan, Alyson N; Rigodanzo, Anna D; Reusch, Ryan T; Brasky, Kathleen M; Meyer, Jerrold S

2018-06-04

Quantifying cortisol concentration in hair is a non-invasive biomarker of long-term hypothalamic-pituitary-adrenal (HPA) activation, and thus can provide important information on laboratory animal health. Marmosets (Callithrix jacchus) and capuchins (Cebus apella) are New World primates increasingly used in biomedical and neuroscience research, yet published hair cortisol concentrations for these species are limited. Review of the existing published hair cortisol values from marmosets reveals highly discrepant values and the use of variable techniques for hair collection, processing, and cortisol extraction. In this investigation we utilized a well-established, standardized protocol to extract and quantify cortisol from marmoset (n = 12) and capuchin (n = 4) hair. Shaved hair samples were collected from the upper thigh during scheduled exams and analyzed via methanol extraction and enzyme immunoassay. In marmosets, hair cortisol concentration ranged from 2,710 to 6,267 pg/mg and averaged 4,070 ± 304 pg/mg. In capuchins, hair cortisol concentration ranged from 621 to 2,089 pg/mg and averaged 1,092 ± 338 pg/mg. Hair cortisol concentration was significantly different between marmosets and capuchins, with marmosets having higher concentrations than capuchins. The incorporation of hair cortisol analysis into research protocols provides a non-invasive measure of HPA axis activity over time, which offers insight into animal health. Utilization of standard protocols across laboratories is essential to obtaining valid measurements and allowing for valuable future cross-species comparisons. © 2018 Wiley Periodicals, Inc.

Long-term follow-up of unilateral transfemoral amputees from the Vietnam war.

PubMed

Dougherty, Paul J

2003-04-01

Despite their frequency, few reports exist concerning the initial and long-term consequences of battle-incurred unilateral transfemoral amputations. A retrospective cohort design was used to measure the long-term health of transfemoral battle amputees treated at a single hospital during the Vietnam War. Data collection consisted of medical record abstraction and a follow-up questionnaire that included the SF-36 Health Survey. Forty-six patients responded to the survey an average of 28 years after injury. Compared with the controls, patient responses to the SF-36 were significantly (p < 0.01) less in all categories except Mental Health and Vitality. Forty-three (93.5%) are or have been married. Forty-one (89.1%) are or have been employed an average of 20.1 years. Forty patients (87%) wore a prosthesis an average of 13.5 h/day. Although the patients do relatively well with employment and marriage stability, the low SF-36 scores suggest a significant disability.

Trends in Streamflow Characteristics at Long-Term Gaging Stations, Hawaii

USGS Publications Warehouse

Oki, Delwyn S.

2004-01-01

The surface-water resources of Hawaii have significant cultural, aesthetic, ecologic, and economic importance. Proper management of the surface-water resources of the State requires an understanding of the long- and short-term variability in streamflow characteristics that may occur. The U.S. Geological Survey maintains a network of stream-gaging stations in Hawaii, including a number of stations with long-term streamflow records that can be used to evaluate long-term trends and short-term variability in flow characteristics. The overall objective of this study is to obtain a better understanding of long-term trends and variations in streamflow on the islands of Hawaii, Maui, Molokai, Oahu, and Kauai, where long-term stream-gaging stations exist. This study includes (1) an analysis of long-term trends in flows (both total flow and estimated base flow) at 16 stream-gaging stations, (2) a description of patterns in trends within the State, and (3) discussion of possible regional factors (including rainfall) that are related to the observed trends and variations. Results of this study indicate the following: 1. From 1913 to 2002 base flows generally decreased in streams for which data are available, and this trend is consistent with the long-term downward trend in annual rainfall over much of the State during that period. 2. Monthly mean base flows generally were above the long-term average from 1913 to the early 1940s and below average after the early 1940s to 2002, and this pattern is consistent with the detected downward trends in base flows from 1913 to 2002. 3. Long-term downward trends in base flows of streams may indicate a reduction in ground-water discharge to streams caused by a long-term decrease in ground-water storage and recharge. 4. From 1973 to 2002, trends in streamflow were spatially variable (up in some streams and down in others) and, with a few exceptions, generally were not statistically significant. 5. Short-term variability in streamflow is related to the seasons and to the EL Ni?o-Southern Oscillation phenomenon that may be partly modulated by the phase of the Pacific Decadal Oscillation. 6. At almost all of the long-term stream-gaging stations considered in this study, average total flow (and to a lesser extent average base flow) during the winter months of January to March tended to be low following El Ni?o periods and high following La Ni?a periods, and this tendency was accentuated during positive phases of the Pacific Decadal Oscillation. 7. The El Ni?o-Southern Oscillation phenomenon occurs at a relatively short time scale (a few to several years) and appears to be more strongly related to processes controlling rainfall and direct runoff than ground-water storage and base flow. Long-term downward trends in base flows of streams may indicate a reduction in ground-water storage and recharge. Because ground water provides about 99 percent of Hawaii's domestic drinking water, a reduction in ground-water storage and recharge has serious implications for drinking-water availability. In addition, reduction in stream base flows may reduce habitat availability for native stream fauna and water availability for irrigation purposes. Further study is needed to determine (1) whether the downward trends in base flows from 1913 to 2002 will continue or whether the observed pattern is part of a long-term cycle in which base flows may eventually return to levels measured during 1913 to the early 1940s, (2) the physical causes for the detected trends and variations in streamflow, and (3) whether regional climate indicators successfully can be used to predict streamflow trends and variations throughout the State. These needs for future study underscore the importance of maintaining a network of long-term-trend stream-gaging stations in Hawaii.

Precipitation; ground-water age; ground-water nitrate concentrations, 1995-2002; and ground-water levels, 2002-03 in Eastern Bernalillo County, New Mexico

USGS Publications Warehouse

Blanchard, Paul J.

2004-01-01

The eastern Bernalillo County study area consists of about 150 square miles and includes all of Bernalillo County east of the crests of the Sandia and Manzanita Mountains. Soil and unconsolidated alluvial deposits overlie fractured and solution-channeled limestone in most of the study area. North of Interstate Highway 40 and east of New Mexico Highway 14, the uppermost consolidated geologic units are fractured sandstones and shales. Average annual precipitation at three long-term National Oceanic and Atmospheric Administration precipitation and snowfall data-collection sites was 14.94 inches at approximately 6,300 feet (Sandia Ranger Station), 19.06 inches at about 7,020 feet (Sandia Park), and 23.07 inches at approximately 10,680 feet (Sandia Crest). The periods of record at these sites are 1933-74, 1939-2001, and 1953-79, respectively. Average annual snowfall during these same periods of record was 27.7 inches at Sandia Ranger Station, 60.8 inches at Sandia Park, and 115.5 inches at Sandia Crest. Seven precipitation data-collection sites were established during December 2000-March 2001. Precipitation during 2001-03 at three U.S. Geological Survey sites ranged from 66 to 94 percent of period-of-record average annual precipitation at corresponding National Oceanic and Atmospheric Administration long-term sites in 2001, from 51 to 75 percent in 2002, and from 34 to 81 percent during January through September 2003. Missing precipitation records for one site resulted in the 34-percent value in 2003. Analyses of concentrations of chlorofluorocarbons CFC-11, CFC-12, and CFC-113 in ground-water samples from nine wells and one spring were used to estimate when the sampled water entered the ground-water system. Apparent ages of ground water ranged from as young as about 10 to 16 years to as old as about 20 to 26 years. Concentrations of dissolved nitrates in samples collected from 24 wells during 2001-02 were similar to concentrations in samples collected from the same wells during 1995, 1997, and (or) 1998. Nitrate concentrations in two wells were larger than the U.S. Environmental Protection Agency primary drinking-water regulation of 10 milligrams per liter in 1998 and in 2001. Ground-water levels were measured during June and July 2002 and during June, July, and August 2003 in 18 monitoring wells. The median change in water level for all 18 wells was a decline of 2.03 feet.

Effect of microalgal treatments on pesticides in water.

PubMed

Hultberg, Malin; Bodin, Hristina; Ardal, Embla; Asp, Håkan

2016-01-01

The effect of the microalgae Chlorella vulgaris on a wide range of different pesticides in water was studied. Treatments included short-term exposure (1 h) to living and dead microalgal biomass and long-term exposure (4 days) to actively growing microalgae. The initial pesticide concentration was 63.5 ± 3.9 µg L(-1). There was no significant overall reduction of pesticides after short-term exposure. A significant reduction of the total amount of pesticides was achieved after the long-term exposure to growing microalgae (final concentration 29.7 ± 1.0 µg L(-1)) compared with the long-term control (37.0 ± 1.2 µg L(-1)). The concentrations of 10 pesticides out of 38 tested were significantly lowered in the long-term algal treatment. A high impact of abiotic factors such as sunlight and aeration for pesticide reduction was observed when the initial control (63.5 ± 3.9 µg L(-1)) and the long-term control (37.0 ± 1.2 µg L(-1)) were compared. The results suggest that water treatment using microalgae, natural inhabitants of polluted surface waters, could be further explored not only for removal of inorganic nutrients but also for removal of organic pollutants in water.

An approach to counteracting long-term microgravity-induced muscle atrophy

NASA Technical Reports Server (NTRS)

Tesch, P. A.; Buchanan, P.; Dudley, G. A.

1990-01-01

To find means of alleviating muscle atrophy induced by long-term microgravity, the effects of a 19-week-long heavy-resistance training regime (using either concentric muscle actions only or concentric and eccentric muscle actions) on the strengths of the exercised knee extensor muscle group were investigated in two groups of male human subjects performing two types of training exercises: supine leg press or/and seated knee extension. Results show that a training program in which both the concentric and the eccentric muscle action was performed led to substantially greater increases in maximal muscle strength than when only concentric exercises were performed.

Watershed characteristics and water-quality trends and loads in 12 watersheds in Gwinnett County, Georgia

USGS Publications Warehouse

Joiner, John K.; Aulenbach, Brent T.; Landers, Mark N.

2014-01-01

The U.S. Geological Survey, in cooperation with Gwinnett County Department of Water Resources, established a Long-Term Trend Monitoring (LTTM) program in 1996. The LTTM program is a comprehensive, long-term, water-quantity and water-quality monitoring program designed to document and analyze the hydrologic and water-quality conditions of selected watersheds of Gwinnett County, Georgia. Water-quality monitoring initially began in six watersheds and was expanded to another six watersheds in 2001. As part of the LTTM program, streamflow, precipitation, water temperature, specific conductance, and turbidity were measured continuously at the 12 watershed monitoring stations for water years 2004–09. In addition, discrete water-quality samples were collected seasonally from May through October (summer) and November through April (winter), including one base-flow and three stormflow event composite samples, during the study period. Samples were analyzed for nutrients (nitrogen and phosphorus), total organic carbon, trace elements (total lead and total zinc), total dissolved solids, and total suspended sediment (total suspended solids and suspended-sediment concentrations). The sampling scheme was designed to identify variations in water quality both hydrologically and seasonally. The 12 watersheds were characterized for basin slope, population density, land use for 2009, and the percentage of impervious area from 2000 to 2009. Precipitation in water years 2004–09 was about 18 percent below average, and the county experienced exceptional drought conditions and below average runoff in water years 2007 and 2008. Watershed water yields, the percentage of precipitation that results in runoff, typically are lower in low precipitation years and are higher for watersheds with the highest percentages of impervious areas. A comparison of base-flow and stormflow water-quality samples indicates that turbidity and concentrations of total ammonia plus organic nitrogen, total nitrogen, total phosphorus, total organic carbon, total lead, total zinc, total suspended solids, and suspended-sediment concentrations increased with increasing discharge at all watersheds. Specific conductance, however, decreased during stormflow at all watersheds, and total dissolved solids concentrations decreased during stormflow at a few of the watersheds. Total suspended solids and suspended-sediment concentrations typically were two orders of magnitude higher in stormflow samples, turbidities were about 1.5 orders of magnitude higher, total phosphorus and total zinc were about one order of magnitude higher, and total ammonia plus organic nitrogen, total nitrogen, total organic carbon, and total lead were about twofold higher than in base-flow samples. Seasonal patterns and long-term trends in flow-adjusted water-quality concentrations were identified for five representative constituents—total nitrogen, total phosphorus, total zinc, total dissolved solids, and total suspended solids. Seasonal patterns for all five constituents were fairly similar, with higher concentrations in the summer and lower concentrations in the winter. Significant linear long-term trends in stormflow composite concentrations were identified for 36 of the 60 constituent-watershed combinations (5 constituents multiplied by 12 watersheds) for the period of record through water year 2011. Significant trends typically were decreasing for total nitrogen, total phosphorus, total suspended solids, and total zinc and increasing for total dissolved solids. Total dissolved solids and total suspended solids trends had the largest magnitude changes per year. Stream water loads were estimated for 10 water-quality constituents. These estimates represent the cumulative effects of watershed characteristics, hydrologic processes, biogeochemical processes, climatic variability, and human influences on watershed water quality. Yields, in load per unit area, were used to compare loads from watersheds with different sizes. A load estimation approach developed for the Gwinnett County LTTM program that incorporates storm-event composited samples was used with some minor modifications. This approach employs the commonly used regression-model method. Concentrations were modeled as a function of discharge, time, season, and turbidity to improve model predictions and reduce errors in load estimates. Total suspended solids annual loads have been identified in Gwinnett County’s Watershed Protection Plan for target performance criterion. The amount of annual runoff is the primary factor in determining the amount of annual constituent loads. Below average runoff during water years 2004–09, especially during water years 2006–08, resulted in corresponding below average loads. Variations in constituent yields between watersheds appeared to be related to various watershed characteristics. Suspended sediment (total suspended solids and suspended-sediment concentrations) along with constituents transported predominately in solid phase (total phosphorus, total organic carbon, total lead, and total zinc) and total dissolved solids typically had higher yields from watersheds that had high percentages of impervious areas or high basin slope. High total nitrogen yields were also associated with watersheds with high percentages of impervious areas. Low total nitrogen, total suspended solids, total lead, and total zinc yields appear to be associated with watersheds that have a low percentage of high-density development. Total suspended solids yields were lower in drought years, water years 2007–08, from the combined effects of less runoff and the result of fewer, lower magnitude storms, which likely resulted in less surface erosion and lower stream sediment transport.

Long-term leaf production response to elevated atmospheric carbon dioxide and tropospheric ozone

Treesearch

Alan F. Talhelm; Kurt S. Pregitzer; Christian P. Giardina

2011-01-01

Elevated concentrations of atmospheric CO2 and tropospheric O3 will profoundly influence future forest productivity, but our understanding of these influences over the long-term is poor. Leaves are key indicators of productivity and we measured the mass, area, and nitrogen concentration of leaves collected in litter traps...

Trends in lake chemistry in response to atmospheric deposition and climate in selected Class I wilderness areas in Colorado, Idaho, Utah, and Wyoming, 1993-2009

USGS Publications Warehouse

Mast, M. Alisa; Ingersoll, George P.

2011-01-01

In 2010, the U.S. Geological Survey, in cooperation with the U.S. Department of Agriculture Forest Service, Air Resource Management, began a study to evaluate long-term trends in lake-water chemistry for 64 high-elevation lakes in selected Class I wilderness areas in Colorado, Idaho, Utah, and Wyoming during 1993 to 2009. The purpose of this report is to describe trends in the chemical composition of these high-elevation lakes. Trends in emissions, atmospheric deposition, and climate variables (air temperature and precipitation amount) are evaluated over a similar period of record to determine likely drivers of changing lake chemistry. Sulfate concentrations in precipitation decreased over the past two decades at high-elevation monitoring stations in the Rocky Mountain region. The trend in deposition chemistry is consistent with regional declines in sulfur dioxide emissions resulting from installation of emission controls at large stationary sources. Trends in nitrogen deposition were not as widespread as those for sulfate. About one-half of monitoring stations showed increases in ammonium concentrations, but few showed significant changes in nitrate concentrations. Trends in nitrogen deposition appear to be inconsistent with available emission inventories, which indicate modest declines in nitrogen emissions in the Rocky Mountain region since the mid-1990s. This discrepancy may reflect uncertainties in emission inventories or changes in atmospheric transformations of nitrogen species that may be affecting deposition processes. Analysis of long-term climate records indicates that average annual mean air temperature minimums have increased from 0.57 to 0.75 °C per decade in mountain areas of the region with warming trends being more pronounced in Colorado. Trends in annual precipitation were not evident over the period 1990 to 2006, although wetter than average years during 1995 to 1997 and drier years during 2001 to 2004 caused a notable decline in precipitation in the middle part of the record.

SPECTRAL SURVEY OF X-RAY BRIGHT ACTIVE GALACTIC NUCLEI FROM THE ROSSI X-RAY TIMING EXPLORER

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rivers, Elizabeth; Markowitz, Alex; Rothschild, Richard, E-mail: erivers@ucsd.edu

2011-03-15

Using long-term monitoring data from the Rossi X-ray Timing Explorer (RXTE), we have selected 23 active galactic nuclei (AGNs) with sufficient brightness and overall observation time to derive broadband X-ray spectra from 3 to {approx}>100 keV. Our sample includes mainly radio-quiet Seyferts, as well as seven radio-loud sources. Given the longevity of the RXTE mission, the greater part of our data is spread out over more than a decade, providing truly long-term average spectra and eliminating inconsistencies arising from variability. We present long-term average values of absorption, Fe line parameters, Compton reflection strengths, and photon indices, as well as fluxesmore » and luminosities for the hard and very hard energy bands, 2-10 keV and 20-100 keV, respectively. We find tentative evidence for high-energy rollovers in three of our objects. We improve upon previous surveys of the very hard X-ray energy band in terms of accuracy and sensitivity, particularly with respect to confirming and quantifying the Compton reflection component. This survey is meant to provide a baseline for future analysis with respect to the long-term averages for these sources and to cement the legacy of RXTE, and especially its High Energy X-ray Timing Experiment, as a contributor to AGN spectral science.« less

The effect of ocean alkalinity and carbon transfer on deep-sea carbonate ion concentration during the past five glacial cycles

NASA Astrophysics Data System (ADS)

Kerr, Joanna; Rickaby, Rosalind; Yu, Jimin; Elderfield, Henry; Sadekov, Aleksey Yu.

2017-08-01

Glacial-interglacial deep Indo-Pacific carbonate ion concentration ([CO32-]) changes were mainly driven by two mechanisms that operated on different timescales: 1) a long-term increase during glaciation caused by a carbonate deposition reduction on shelves (i.e., the coral reef hypothesis), and 2) transient carbonate compensation responses to deep ocean carbon storage changes. To investigate these mechanisms, we have used benthic foraminiferal B/Ca to reconstruct deep-water [CO32-] in cores from the deep Indian and Equatorial Pacific Oceans during the past five glacial cycles. Based on our reconstructions, we suggest that the shelf-to-basin shift of carbonate deposition raised deep-water [CO32-], on average, by 7.3 ± 0.5 (SE) μmol/kg during glaciations. Oceanic carbon reorganisations during major climatic transitions caused deep-water [CO32-] deviations away from the long-term trend, and carbonate compensation processes subsequently acted to restore the ocean carbonate system to new steady state conditions. Deep-water [CO32-] showed similar patterns to sediment carbonate content (%CaCO3) records on glacial-interglacial timescales, suggesting that past seafloor %CaCO3 variations were dominated by deep-water carbonate preservation changes at our studied sites.

The effect of communication change on long-term reductions in child exposure to conflict: impact of the promoting strong African American families (ProSAAF) program.

PubMed

Beach, Steven R H; Barton, Allen W; Lei, Man Kit; Brody, Gene H; Kogan, Steven M; Hurt, Tera R; Fincham, Frank D; Stanley, Scott M

2014-12-01

African American couples (n = 331) with children, 89% of whom were married, were assigned to either (a) a culturally sensitive couple- and parenting-enhancement program (ProSAAF) or (b) an information-only control condition in which couples received self-help materials. Husbands averaged 41 years of age and wives averaged 39 years. We found significant effects of program participation in the short term on couple communication, which was targeted by the intervention, as well as over the long term, on self-reported arguing in front of children. Long-term parenting outcomes were fully mediated by changes in communication for wives, but not for husbands. For husbands, positive change depended on amount of wife reported change. We conclude that wives' changes in communication from baseline to posttest may be more pivotal for the couples' long-term experience of decreased arguing in front of children than are husbands' changes, with wives' changes leading to changes in both partners' reports of arguments in front of children. © 2014 Family Process Institute.

A comparative modeling analysis of multiscale temporal variability of rainfall in Australia

NASA Astrophysics Data System (ADS)

Samuel, Jos M.; Sivapalan, Murugesu

2008-07-01

The effects of long-term natural climate variability and human-induced climate change on rainfall variability have become the focus of much concern and recent research efforts. In this paper, we present the results of a comparative analysis of observed multiscale temporal variability of rainfall in the Perth, Newcastle, and Darwin regions of Australia. This empirical and stochastic modeling analysis explores multiscale rainfall variability, i.e., ranging from short to long term, including within-storm patterns, and intra-annual, interannual, and interdecadal variabilities, using data taken from each of these regions. The analyses investigated how storm durations, interstorm periods, and average storm rainfall intensities differ for different climate states and demonstrated significant differences in this regard between the three selected regions. In Perth, the average storm intensity is stronger during La Niña years than during El Niño years, whereas in Newcastle and Darwin storm duration is longer during La Niña years. Increase of either storm duration or average storm intensity is the cause of higher average annual rainfall during La Niña years as compared to El Niño years. On the other hand, within-storm variability does not differ significantly between different ENSO states in all three locations. In the case of long-term rainfall variability, the statistical analyses indicated that in Newcastle the long-term rainfall pattern reflects the variability of the Interdecadal Pacific Oscillation (IPO) index, whereas in Perth and Darwin the long-term variability exhibits a step change in average annual rainfall (up in Darwin and down in Perth) which occurred around 1970. The step changes in Perth and Darwin and the switch in IPO states in Newcastle manifested differently in the three study regions in terms of changes in the annual number of rainy days or the average daily rainfall intensity or both. On the basis of these empirical data analyses, a stochastic rainfall time series model was developed that incorporates the entire range of multiscale variabilities observed in each region, including within-storm, intra-annual, interannual, and interdecadal variability. Such ability to characterize, model, and synthetically generate realistic time series of rainfall intensities is essential for addressing many hydrological problems, including estimation of flood and drought frequencies, pesticide risk assessment, and landslide frequencies.

Analysis of the long and short-period terms due the nonsphericity of the central body: applications for Mercury

NASA Astrophysics Data System (ADS)

Carvalho, J. P. S.

2017-10-01

In this work, we present an approach taking into account the single-averaged equations and unaveraged equations to investigate the dynamics of artificial satellites on the effect due to the non-spherical shape of the planet Mercury. An analysis considering the long-period terms and another taking into account the short-period terms is presented. The numerical integrations of the equations developed are performed using the Maple software. We consider the numerical values of the most updated spherical harmonic coefficients in the literature. Emphasis is given to analyze the effect of the C22 term in the dynamics of the spacecraft. We show that the two techniques are in agreement (average or not average). We found orbits that librates around an equilibrium point with small variation of the orbital elements, in particular the eccentricity and argument of the pericenter. We also note that the C22 term contributes to reduce the growth of the orbital eccentricity.

A joint prevention and control mechanism for air pollution in the Beijing-Tianjin-Hebei region in china based on long-term and massive data mining of pollutant concentration

NASA Astrophysics Data System (ADS)

Wang, Hongbo; Zhao, Laijun

2018-02-01

China's Beijing-Tianjin-Hebei (BTH) region suffers from the country's worst air pollution. The problem has caused widespread concern both at home and abroad. Based on long-term and massive data mining of PM2.5 and PM10 concentration, we found that these pollutants showed similar variations in four seasons, but the most severe pollution was in winter. Through cluster analysis of the winter daily average concentration (DAC) of the two pollutants, we defined regions with similar variations in pollutant concentrations in winter. For the most polluted cities in BTH, the relationship between correlation coefficients for winter DAC and the distance between cities revealed that PM2.5 has regional, large-scale characteristics, with concentrated outbreaks, whereas PM10 has local, small-scale characteristics, with outbreaks at multiple locations. By selecting the key cities with the strongest linear relationship between the pollutant's DAC of each city and the daily individual air quality index values of the BTH region and through cluster analysis on the correlations between the pollutant DACs of the key cities, we defined regional divisions suitable for Joint Prevention and Control of Atmospheric Pollution (JPCAP) program to control PM2.5 and PM10. Comprehensively considering the degree of influence of regional atmospheric pollution control (RAPC) on air quality in BTH, as well as the elasticity and urgency of RAPC, we defined the control grades of the JPCAP regions. We found both the regions and corresponding control grades were consistent for PM2.5 and PM10. The thinking and methods of atmospheric pollution control we proposed will have broad significance for implementation of RAPC in other regions around the world.

Associations of Spatial Disparities of Alzheimer's Disease Mortality Rates with Soil Selenium and Sulfur Concentrations and Four Common Risk Factors in the United States.

PubMed

Sun, Hongbing

2017-01-01

Associations between environmental factors and spatial disparity of mortality rates of Alzheimer's disease (AD) in the US are not well understood. To find associations between 41 trace elements, four common risk factors, and AD mortality rates in the48 contiguous states. Isopleth maps of AD mortality rates of the 48 states and associated factors were examined. Correlations between state average AD mortality rates and concentrations of 41 soil elements, wine consumption, percentage of current smokers, obesity, and diagnosed diabetes of the 48 states between 1999 and 2014 were analyzed. Among 41 elements, soil selenium concentrations have the most significant inverse correlations with AD mortality rates. Rate ratio (RR) of the 6 states with the lowest product of soil selenium and sulfur concentrations is 53% higher than the 6 states with the highest soil selenium sulfur product in the 48 states (RR = 1.53, CI95% 1.51-1.54). Soil tin concentrations have the most significant inverse correlation with AD mortality growth rates between 1999 and 2014, followed by soil sulfur concentrations. Percentages of obesity, diagnosed diabetes, smoking, and wine consumption per capita also correlate significantly with AD mortality growth rates. High soil selenium and sulfur concentrations and wine consumption are associated with low AD mortality rates. Given that average soil selenium and sulfur concentrations are indicators of their intakes from food, water, and air by people in a region, long-term exposure to high soil selenium and sulfur concentrations might be beneficial to AD mortality rate reduction in a region.

Optimal estimation of suspended-sediment concentrations in streams

USGS Publications Warehouse

Holtschlag, D.J.

2001-01-01

Optimal estimators are developed for computation of suspended-sediment concentrations in streams. The estimators are a function of parameters, computed by use of generalized least squares, which simultaneously account for effects of streamflow, seasonal variations in average sediment concentrations, a dynamic error component, and the uncertainty in concentration measurements. The parameters are used in a Kalman filter for on-line estimation and an associated smoother for off-line estimation of suspended-sediment concentrations. The accuracies of the optimal estimators are compared with alternative time-averaging interpolators and flow-weighting regression estimators by use of long-term daily-mean suspended-sediment concentration and streamflow data from 10 sites within the United States. For sampling intervals from 3 to 48 days, the standard errors of on-line and off-line optimal estimators ranged from 52.7 to 107%, and from 39.5 to 93.0%, respectively. The corresponding standard errors of linear and cubic-spline interpolators ranged from 48.8 to 158%, and from 50.6 to 176%, respectively. The standard errors of simple and multiple regression estimators, which did not vary with the sampling interval, were 124 and 105%, respectively. Thus, the optimal off-line estimator (Kalman smoother) had the lowest error characteristics of those evaluated. Because suspended-sediment concentrations are typically measured at less than 3-day intervals, use of optimal estimators will likely result in significant improvements in the accuracy of continuous suspended-sediment concentration records. Additional research on the integration of direct suspended-sediment concentration measurements and optimal estimators applied at hourly or shorter intervals is needed.

Long-Term Trends Worldwide in Ambient NO2 Concentrations Inferred from Satellite Observations.

PubMed

Geddes, Jeffrey A; Martin, Randall V; Boys, Brian L; van Donkelaar, Aaron

2016-03-01

Air pollution is associated with morbidity and premature mortality. Satellite remote sensing provides globally consistent decadal-scale observations of ambient nitrogen dioxide (NO2) pollution. We determined global population-weighted annual mean NO2 concentrations from 1996 through 2012. We used observations of NO2 tropospheric column densities from three satellite instruments in combination with chemical transport modeling to produce a global 17-year record of ground-level NO2 at 0.1° × 0.1° resolution. We calculated linear trends in population-weighted annual mean NO2 (PWMNO2) concentrations in different regions around the world. We found that PWMNO2 in high-income North America (Canada and the United States) decreased more steeply than in any other region, having declined at a rate of -4.7%/year [95% confidence interval (CI): -5.3, -4.1]. PWMNO2 decreased in western Europe at a rate of -2.5%/year (95% CI: -3.0, -2.1). The highest PWMNO2 occurred in high-income Asia Pacific (predominantly Japan and South Korea) in 1996, with a subsequent decrease of -2.1%/year (95% CI: -2.7, -1.5). In contrast, PWMNO2 almost tripled in East Asia (China, North Korea, and Taiwan) at a rate of 6.7%/year (95% CI: 6.0, 7.3). The satellite-derived estimates of trends in ground-level NO2 were consistent with regional trends inferred from data obtained from ground-station monitoring networks in North America (within 0.7%/year) and Europe (within 0.3%/year). Our rankings of regional average NO2 and long-term trends differed from the satellite-derived estimates of fine particulate matter reported elsewhere, demonstrating the utility of both indicators to describe changing pollutant mixtures. Long-term trends in satellite-derived ambient NO2 provide new information about changing global exposure to ambient air pollution. Our estimates are publicly available at http://fizz.phys.dal.ca/~atmos/martin/?page_id=232.

40 CFR 439.52 - Effluent limitations attainable by the application of the best practicable control technology...

Code of Federal Regulations, 2011 CFR

2011-07-01

... day, must reflect not less than 74 percent reduction in the long-term average daily COD load of the... required to attain a limitation for COD that is less than the equivalent of 220 mg/L. (d) The long-term... of NPDES permit limitations regulating discharges subject to this subpart, calculation of the long...

40 CFR 439.52 - Effluent limitations attainable by the application of the best practicable control technology...

Code of Federal Regulations, 2010 CFR

2010-07-01

... day, must reflect not less than 74 percent reduction in the long-term average daily COD load of the... required to attain a limitation for COD that is less than the equivalent of 220 mg/L. (d) The long-term... of NPDES permit limitations regulating discharges subject to this subpart, calculation of the long...

A Flexible Spatio-Temporal Model for Air Pollution with Spatial and Spatio-Temporal Covariates.

PubMed

Lindström, Johan; Szpiro, Adam A; Sampson, Paul D; Oron, Assaf P; Richards, Mark; Larson, Tim V; Sheppard, Lianne

2014-09-01

The development of models that provide accurate spatio-temporal predictions of ambient air pollution at small spatial scales is of great importance for the assessment of potential health effects of air pollution. Here we present a spatio-temporal framework that predicts ambient air pollution by combining data from several different monitoring networks and deterministic air pollution model(s) with geographic information system (GIS) covariates. The model presented in this paper has been implemented in an R package, SpatioTemporal, available on CRAN. The model is used by the EPA funded Multi-Ethnic Study of Atherosclerosis and Air Pollution (MESA Air) to produce estimates of ambient air pollution; MESA Air uses the estimates to investigate the relationship between chronic exposure to air pollution and cardiovascular disease. In this paper we use the model to predict long-term average concentrations of NO x in the Los Angeles area during a ten year period. Predictions are based on measurements from the EPA Air Quality System, MESA Air specific monitoring, and output from a source dispersion model for traffic related air pollution (Caline3QHCR). Accuracy in predicting long-term average concentrations is evaluated using an elaborate cross-validation setup that accounts for a sparse spatio-temporal sampling pattern in the data, and adjusts for temporal effects. The predictive ability of the model is good with cross-validated R 2 of approximately 0.7 at subject sites. Replacing four geographic covariate indicators of traffic density with the Caline3QHCR dispersion model output resulted in very similar prediction accuracy from a more parsimonious and more interpretable model. Adding traffic-related geographic covariates to the model that included Caline3QHCR did not further improve the prediction accuracy.

Effectiveness of Emission Controls to Reduce the Atmospheric Concentrations of Mercury.

PubMed

Castro, Mark S; Sherwell, John

2015-12-15

Coal-fired power plants in the United States are required to reduce their emissions of mercury (Hg) into the atmosphere to lower the exposure of Hg to humans. The effectiveness of power-plant emission controls on the atmospheric concentrations of Hg in the United States is largely unknown because there are few long-term high-quality atmospheric Hg data sets. Here, we present the atmospheric concentrations of Hg and sulfur dioxide (SO2) measured from 2006 to 2015 at a relatively pristine location in western Maryland that is several (>50 km) kilometers downwind of power plants in Ohio, Pennsylvania, and West Virginia. Annual average atmospheric concentrations of gaseous oxidized mercury (GOM), SO2, fine particulate mercury (PBM2.5), and gaseous elemental mercury (GEM) declined by 75%, 75%, 43%, and 13%, respectively, and were strongly correlated with power-plant Hg emissions from the upwind states. These results provide compelling evidence that reductions in Hg emissions from power plants in the United States had their intended impact to reduce regional Hg pollution.

Storm water runoff concentration matrix for urban areas.

PubMed

Göbel, P; Dierkes, C; Coldewey, W G

2007-04-01

The infrastructure (roads, sidewalk, commercial and residential structures) added during the land development and urbanisation process is designed to collect precipitation and convey it out of the watershed, typically in existing surface water channels, such as streams and rivers. The quality of surface water, seepage water and ground water is influenced by pollutants that collect on impervious surfaces and that are carried by urban storm water runoff. Heavy metals, e.g. lead (Pb), zinc (Zn), copper (Cu), cadmium (Cd), polycyclic aromatic hydrocarbons (PAH), mineral oil hydrocarbons (MOH) and readily soluble salts in runoff, contribute to the degradation of water. An intensive literature search on the distribution and concentration of the surface-dependent runoff water has been compiled. Concentration variations of several pollutants derived from different surfaces have been averaged. More than 300 references providing about 1300 data for different pollutants culminate in a representative concentration matrix consisting of medians and extreme values. This matrix can be applied to long-term valuations and numerical modelling of storm water treatment facilities.

Assessing Provincial PM2.5 Trends in China from 2001 to 2015 Using High-Resolution Satellite Remote Sensing

NASA Astrophysics Data System (ADS)

Lin, C.; Lau, A. K. H.; LI, Y.; Li, C.

2017-12-01

Given the vast territory of China, control efforts for air pollution and the long-term PM2.5 trends may substantially differ among the provinces. In this study, we aim to assess the provincial PM2.5 trends in China during the past few Five-Year Plan (FYP) periods. The lack of long-term PM2.5 measurements, however, makes such assessment difficult. Satellite remote sensing of PM2.5 concentration is an important step toward filling this data gap. In this study, a PM2.5 data set was built over China at a resolution of 1 km from 2001 to 2015 using satellite remote sensing. Analyses show that the national average of PM2.5 concentration increased by 0.11 µg·m-3·yr-1 during the 10th FYP period (2001 to 2005) and started to decline by -0.75 µg·m-3·yr-1 and -2.20 µg·m-3·yr-1 during the 11th (2006 to 2010) and the 12th (2011 to 2015) FYP period, respectively. In addition, substantial differences in the PM2.5 trends were observed among the provinces. Although PM2.5 concentrations remained steady or worsened in most provinces during the 10th FYP period, PM2.5 concentrations substantially declined for provinces in the Beijing-Tianjin-Hebei (BTH) region, suggesting that these provinces were the most successful in their control efforts during this period. The most substantial decline in provincial PM2.5 concentration during the 12th FYP period was also observed in the BTH region. In contrast, PM2.5 concentrations remained steady for provinces in eastern and southeastern China (e.g., Shanghai) during the 12th FYP period, suggesting that these provinces have been less successful in controlling PM2.5 concentrations since 2011 and therefore require more efforts to effectively reduce the PM2.5 concentrations in future.

Long-term observations of saccharides in remote marine aerosols from the western North Pacific: A comparison between 1990-1993 and 2006-2009 periods

NASA Astrophysics Data System (ADS)

Chen, Jing; Kawamura, Kimitaka; Liu, Cong-Qiang; Fu, Pingqing

2013-03-01

Anhydrosugars (galactosan, mannosan and levoglucosan), sugars (xylose, fructose, glucose, sucrose and trehalose) and sugar alcohols (erythritol, arabitol, mannitol and inositol) were measured in the aerosol samples collected in a remote island (Chichi-Jima, Japan) in the western North Pacific from 1990 to 1993 and from 2006 to 2009. Total concentrations of anhydrosugars, the biomass burning tracers, were 0.01-5.57 ng m-3 (average 0.76 ng m-3) during 1990-1993 versus 0.01-7.19 ng m-3 (0.64 ng m-3) during 2006-2009. Their seasonal variations were characterized by winter/spring maxima and summer/fall minima. Such a seasonal pattern should be caused by the enhanced long-range atmospheric transport of biomass burning products and terrestrial organic matter (such as higher plant detritus and soil dust) from the Asian continent in winter/spring seasons, when the westerly or winter monsoon system prevails over the western North Pacific. Sugars and sugar alcohols showed different seasonal patterns. The monthly mean concentrations of erythritol, arabitol, mannitol, inositol, fructose, glucose and trehalose were found to be higher in spring/summer and lower in fall/winter during both 1990-1993 and 2006-2009 periods, indicating an enhanced biogenic emission of aerosols in warm seasons. Interestingly, saccharides showed a gradual decrease in their concentrations from 1991 to 1993 and an increase from 2006 to 2009. In addition, the monthly averaged concentrations of sugars and sugar alcohols showed maxima in early summer during 1990-1993, which occurred about 1-2 months earlier than those during 2006-2009. Such a clear seasonal shift may be attributable to the changes in the strength of westerly and trade wind systems during two periods.

Analysis of the distributions of hourly NO2 concentrations contributing to annual average NO2 concentrations across the European monitoring network between 2000 and 2014

NASA Astrophysics Data System (ADS)

Malley, Christopher S.; von Schneidemesser, Erika; Moller, Sarah; Braban, Christine F.; Hicks, W. Kevin; Heal, Mathew R.

2018-03-01

Exposure to nitrogen dioxide (NO2) is associated with negative human health effects, both for short-term peak concentrations and from long-term exposure to a wider range of NO2 concentrations. For the latter, the European Union has established an air quality limit value of 40 µg m-3 as an annual average. However, factors such as proximity and strength of local emissions, atmospheric chemistry, and meteorological conditions mean that there is substantial variation in the hourly NO2 concentrations contributing to an annual average concentration. The aim of this analysis was to quantify the nature of this variation at thousands of monitoring sites across Europe through the calculation of a standard set of chemical climatology statistics. Specifically, at each monitoring site that satisfied data capture criteria for inclusion in this analysis, annual NO2 concentrations, as well as the percentage contribution from each month, hour of the day, and hourly NO2 concentrations divided into 5 µg m-3 bins were calculated. Across Europe, 2010-2014 average annual NO2 concentrations (NO2AA) exceeded the annual NO2 limit value at 8 % of > 2500 monitoring sites. The application of this chemical climatology approach showed that sites with distinct monthly, hour of day, and hourly NO2 concentration bin contributions to NO2AA were not grouped into specific regions of Europe, furthermore, within relatively small geographic regions there were sites with similar NO2AA, but with differences in these contributions. Specifically, at sites with highest NO2AA, there were generally similar contributions from across the year, but there were also differences in the contribution of peak vs. moderate hourly NO2 concentrations to NO2AA, and from different hours across the day. Trends between 2000 and 2014 for 259 sites indicate that, in general, the contribution to NO2AA from winter months has increased, as has the contribution from the rush-hour periods of the day, while the contribution from peak hourly NO2 concentrations has decreased. The variety of monthly, hour of day and hourly NO2 concentration bin contributions to NO2AA, across cities, countries and regions of Europe indicate that within relatively small geographic areas different interactions between emissions, atmospheric chemistry and meteorology produce variation in NO2AA and the conditions that produce it. Therefore, measures implemented to reduce NO2AA in one location may not be as effective in others. The development of strategies to reduce NO2AA for an area should therefore consider (i) the variation in monthly, hour of day, and hourly NO2 concentration bin contributions to NO2AA within that area; and (ii) how specific mitigation actions will affect variability in hourly NO2 concentrations.

The effects of a secondary-treated bleached kraft mill effluent on aquatic organisms as assessed by short-term and long-term laboratory tests.

PubMed

Kovacs, T G; Gibbons, J S; Tremblay, L A; O'Connor, B I; Martel, P H; Voss, R H

1995-06-01

The chronic effects of secondary-treated effluent from a bleached kraft mill were assessed by means of long-term and short-term laboratory tests. In the long-term test, the effects of the effluent on the life cycle of fathead minnows (Pimephales promelas) were studied. In this experiment, which began with the egg stage and continued through to sexual maturity and reproduction, the fish were exposed in the laboratory to well water (control) and five concentrations (viz., 1.25, 2.5, 5, 10, or 20%) of effluent for 275 days. The effluent concentrations did not significantly affect the hatching of the eggs, the mortality of the hatched fish, the incidence of visible morphological abnormalities, the mortality and the hatchability of the first generation eggs and larvae, and the weights of minnows at various stages of development. Based on a conservative evaluation of the data, a significant finding of this work was that effluent concentrations > or = 2.5% caused lower egg production as well as changes in the gender balance (i.e., increased numbers of individuals with male secondary sexual characteristics) of the fish. Further work is required to understand the causes and ecological significance of these findings. Two short-term tests, each lasting 7 days, were also run. In one, even 100% effluent did not reduce the survival or growth of minnow larvae, correctly predicting the lack of effluent effects on similar endpoints in the long-term test. In the other short-term test, while the survival of Ceriodaphnia was also unaffected by 100% effluent, their reproductive capacity was reduced, but only at effluent concentrations an order of magnitude greater than those affecting the reproduction of minnows in the long-term test.

Cross-correlations between agricultural commodity futures markets in the US and China

NASA Astrophysics Data System (ADS)

Li, Zhihui; Lu, Xinsheng

2012-08-01

This paper examines the cross-correlation properties of agricultural futures markets between the US and China using a cross-correlation statistic test and multifractal detrended cross-correlation analysis (MF-DCCA). The results show that the cross-correlations between the two geographically distant markets for four pairs of important agricultural commodities futures are significantly multifractal. By introducing the concept of a “crossover”, we find that the multifractality of cross-correlations between the two markets is not long lasting. The cross-correlations in the short term are more strongly multifractal, but they are weakly so in the long term. Moreover, cross-correlations of small fluctuations are persistent and those of large fluctuations are anti-persistent in the short term while cross-correlations of all kinds of fluctuations for soy bean and soy meal futures are persistent and for corn and wheat futures are anti-persistent in the long term. We also find that cross-correlation exponents are less than the averaged generalized Hurst exponent when q<0 and more than the averaged generalized Hurst exponent when q>0 in the short term, while in the long term they are almost the same.

42 CFR 447.255 - Related information.

Code of Federal Regulations, 2011 CFR

2011-10-01

... assurances described in § 447.253(a), the following information: (a) The amount of the estimated average... which that estimated average rate increased or decreased relative to the average payment rate in effect... and, to the extent feasible, long-term effect the change in the estimated average rate will have on...

Plate tectonics and continental basaltic geochemistry throughout Earth history

NASA Astrophysics Data System (ADS)

Keller, Brenhin; Schoene, Blair

2018-01-01

Basaltic magmas constitute the primary mass flux from Earth's mantle to its crust, carrying information about the conditions of mantle melting through which they were generated. As such, changes in the average basaltic geochemistry through time reflect changes in underlying parameters such as mantle potential temperature and the geodynamic setting of mantle melting. However, sampling bias, preservation bias, and geological heterogeneity complicate the calculation of representative average compositions. Here we use weighted bootstrap resampling to minimize sampling bias over the heterogeneous rock record and obtain maximally representative average basaltic compositions through time. Over the approximately 4 Ga of the continental rock record, the average composition of preserved continental basalts has evolved along a generally continuous trajectory, with decreasing compatible element concentrations and increasing incompatible element concentrations, punctuated by a comparatively rapid transition in some variables such as La/Yb ratios and Zr, Nb, and Ti abundances approximately 2.5 Ga ago. Geochemical modeling of mantle melting systematics and trace element partitioning suggests that these observations can be explained by discontinuous changes in the mineralogy of mantle partial melting driven by a gradual decrease in mantle potential temperature, without appealing to any change in tectonic process. This interpretation is supported by the geochemical record of slab fluid input to continental basalts, which indicates no long-term change in the global proportion of arc versus non-arc basaltic magmatism at any time in the preserved rock record.

Chloride circulation in a lowland catchment and the formulation of transport by travel time distributions

NASA Astrophysics Data System (ADS)

Benettin, Paolo; van der Velde, Ype; van der Zee, Sjoerd E. A. T. M.; Rinaldo, Andrea; Botter, Gianluca

2013-08-01

Travel times are fundamental catchment descriptors that blend key information about storage, geochemistry, flow pathways and sources of water into a coherent mathematical framework. Here we analyze travel time distributions (TTDs) (and related attributes) estimated on the basis of the extensive hydrochemical information available for the Hupsel Brook lowland catchment in the Netherlands. The relevance of the work is perceived to lie in the general importance of characterizing nonstationary TTDs to capture catchment transport properties, here chloride flux concentrations at the basin outlet. The relative roles of evapotranspiration, water storage dynamics, hydrologic pathways and mass sources/sinks are discussed. Different hydrochemical models are tested and ranked, providing compelling examples of the improved process understanding achieved through coupled calibration of flow and transport processes. The ability of the model to reproduce measured flux concentrations is shown to lie mostly in the description of nonstationarities of TTDs at multiple time scales, including short-term fluctuations induced by soil moisture dynamics in the root zone and long-term seasonal dynamics. Our results prove reliable and suggest, for instance, that drastically reducing fertilization loads for one or more years would not result in significant permanent decreases in average solute concentrations in the Hupsel runoff because of the long memory shown by the system. Through comparison of field and theoretical evidence, our results highlight, unambiguously, the basic transport mechanisms operating in the catchment at hand, with a view to general applications.

Oxygen dynamics in a boreal lake responds to long-term changes in climate, ice phenology, and DOC inputs

NASA Astrophysics Data System (ADS)

Couture, Raoul-Marie; de Wit, Heleen A.; Tominaga, Koji; Kiuru, Petri; Markelov, Igor

2015-11-01

Boreal lakes are impacted by climate change, reduced acid deposition, and changing loads of dissolved organic carbon (DOC) from catchments. We explored, using the process-based lake model MyLake, how changes in these pressures modulate ice phenology and the dissolved oxygen concentrations (DO) of a small boreal humic lake. The model was parametrized against year-round time series of water temperature and DO from a lake buoy. Observed trends in air temperature (+0.045°C yr-1) and DOC concentration (0.11 mg C L-1 yr-1, +1% annually) over the past 40 years were used as model forcings. A backcast of ice freezing and breakup dates revealed that ice breakup occurred on average 8 days earlier in 2014 than in 1974. The earlier ice breakup enhanced water column ventilation resulting in higher DO in the spring. Warmer water in late summer led to longer anoxic periods, as microbial DOC turnover increased. A long-term increase in DOC concentrations caused a decline in lake DO, leading to 15% more hypoxic days (<3 mg L-1) and 10% more anoxic days (<15 µg L-1) in 2014 than in 1974. We conclude that climate warming and increasing DOC loads are antagonistic with respect to their effect on DO availability. The model suggests that DOC is a stronger driver of DO consumption than temperature. The browning of lakes may thus cause reductions in the oxythermal habitat of fish and aquatic biota in boreal lakes.

Purification of recombinant human secretory phospholipase A2 (group II) produced in long-term immobilized cell culture.

PubMed

Levin, W; Daniel, R F; Stoner, C R; Stoller, T J; Wardwell-Swanson, J A; Angelillo, Y M; Familletti, P C; Crowl, R M

1992-02-01

Recombinant human secretory phospholipase A2 (Group II) was expressed in long-term culture of immobilized Chinese hamster ovary cells utilizing a continuous-perfusion airlift bioreactor. The bioreactor was continuously perfused with cell-culture medium supplemented with 5% fetal calf serum at an average flow rate of 5 liters/day for 30 days. Recombinant phospholipase A2, at concentrations ranging from 100 to 500 micrograms/liter, was purified to apparent homogeneity by an efficient two-step procedure involving a silica-based cation-exchange resin and hydrophobic interaction chromatography (greater than 65% recovery of phospholipase A2). The purified recombinant protein has an apparent molecular weight of 16 kDa, identical to that of purified human placental or synovial fluid phospholipase A2, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Application of the purified protein onto several different gel filtration columns resulted in elution of the protein at molecular weights corresponding to 3.1-4.7 kDa, suggesting an interaction of the protein with the column resins. However, analytical ultracentrifugation experiments revealed that the protein behaves as a monomer (13.8-14.2 kDa) over a protein concentration range of approximately 10 micrograms/ml to 5 mg/ml. With autoclaved Escherichia coli membranes as substrate, the recombinant protein has catalytic properties (pH optimum, effects of bovine serum albumin, sodium chloride concentration, and requirement for calcium) similar to those of the protein purified from human placenta.

Early Postimplant Speech Perception and Language Skills Predict Long-Term Language and Neurocognitive Outcomes Following Pediatric Cochlear Implantation

PubMed Central

Kronenberger, William G.; Castellanos, Irina; Pisoni, David B.

2017-01-01

Purpose We sought to determine whether speech perception and language skills measured early after cochlear implantation in children who are deaf, and early postimplant growth in speech perception and language skills, predict long-term speech perception, language, and neurocognitive outcomes. Method Thirty-six long-term users of cochlear implants, implanted at an average age of 3.4 years, completed measures of speech perception, language, and executive functioning an average of 14.4 years postimplantation. Speech perception and language skills measured in the 1st and 2nd years postimplantation and open-set word recognition measured in the 3rd and 4th years postimplantation were obtained from a research database in order to assess predictive relations with long-term outcomes. Results Speech perception and language skills at 6 and 18 months postimplantation were correlated with long-term outcomes for language, verbal working memory, and parent-reported executive functioning. Open-set word recognition was correlated with early speech perception and language skills and long-term speech perception and language outcomes. Hierarchical regressions showed that early speech perception and language skills at 6 months postimplantation and growth in these skills from 6 to 18 months both accounted for substantial variance in long-term outcomes for language and verbal working memory that was not explained by conventional demographic and hearing factors. Conclusion Speech perception and language skills measured very early postimplantation, and early postimplant growth in speech perception and language, may be clinically relevant markers of long-term language and neurocognitive outcomes in users of cochlear implants. Supplemental materials https://doi.org/10.23641/asha.5216200 PMID:28724130

An assessment of hopanes in settled dust and air as indicators of exposure to traffic-related air pollution in Windsor, Ontario

NASA Astrophysics Data System (ADS)

Curran, Jason

Traffic-related air pollution (TRAP) has been linked with several adverse health effects. We investigated hopanes, markers of primary particle emissions from gasoline and diesel engines, in house dust as an alternative approach for assessing exposure to TRAP in Windsor, Ontario. Settled house dust was collected from the homes of 28 study participants (10 -- 13 yrs). The dust was then analyzed for a suite of hopanes by gas chromatography-mass spectrometry. We calculated correlations between dust hopane concentrations and estimates of annual average NO2 concentrations derived from an existing LUR model. Hopanes were consistently present in detectable quantities in house dust. Annual average outdoor NO2 estimated was moderately correlated with hopanes in house dust (r = 0.46; p<0.05). The correlations did not vary by infiltration efficiency or the presence of an attached garage. Hopanes measured in settled house dust show promise as an indicator of long-term exposure to traffic-related air pollution. Keywords: hopane; air pollution; traffic; dust; exposure; TRAP.

How robust are the estimated effects of air pollution on health? Accounting for model uncertainty using Bayesian model averaging.

PubMed

Pannullo, Francesca; Lee, Duncan; Waclawski, Eugene; Leyland, Alastair H

2016-08-01

The long-term impact of air pollution on human health can be estimated from small-area ecological studies in which the health outcome is regressed against air pollution concentrations and other covariates, such as socio-economic deprivation. Socio-economic deprivation is multi-factorial and difficult to measure, and includes aspects of income, education, and housing as well as others. However, these variables are potentially highly correlated, meaning one can either create an overall deprivation index, or use the individual characteristics, which can result in a variety of pollution-health effects. Other aspects of model choice may affect the pollution-health estimate, such as the estimation of pollution, and spatial autocorrelation model. Therefore, we propose a Bayesian model averaging approach to combine the results from multiple statistical models to produce a more robust representation of the overall pollution-health effect. We investigate the relationship between nitrogen dioxide concentrations and cardio-respiratory mortality in West Central Scotland between 2006 and 2012. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Long-term effects of commercial sawlog harvest on soil cation concentrations

Treesearch

Jennifer D. Knoepp; Wayne T. Swank

1997-01-01

There is increasing concern about the effects of nutrient removal associated with various forest harvesting practices on long-term site productivity. The authors measured exchangeable soil cation concentration responses to a commercial clearcut sawlog harvest in mixed hardwoods on a 59-ha watershed in the Southern Appalachians. Soils were sampled 17 months prior to and...

Atmospheric emissions and trends of nitrous oxide deduced from 10 years of ALE-GAGE data

NASA Technical Reports Server (NTRS)

Prinn, R.; Cunnold, D.; Alyea, F.; Rasmussen, R.; Simmonds, P.

1990-01-01

Long-term measurements of nitrous oxide (N2O) obtained during the Atmospheric Lifetime Experiment (ALE) and the Global Atmospheric Gases Experiment (GAGE) for a period from 1978 to 1988 are presented and interpreted. It is observed that the average concentration in the Northern Hemisphere is 0.75 +/- 0.16 ppbv higher than in the Southern Hemisphere and that the global average linear trend in N2O lies in the range from 0.25 to 0.31 percent/year. The measured trends and latitudinal distributions are shown to be consistent with the hypothesis that stratospheric photodissociation is the major atmospheric sink for N2O, while the cause of the N2O trend is suggested to be a combination of a growing tropical source and a growing Northern mid-latitude source. A 10-year average global N2O emission rate of (20.5 +/- 2.4) x 10 to the 12th g N2O/year is deduced from the ALE/GAGE data.

Hydrologic reconnaissance of the Wasatch Plateau-Book Cliffs coal-fields area, Utah

USGS Publications Warehouse

Waddell, Kidd M.; Contratto, P. Kay; Sumsion, C.T.; Butler, John R.

1981-01-01

Data obtained during a hydrologic reconnaissance in 1975-77 in the Wasatch Plateau-Book Cliffs coal-fields area of Utah were correlated with existing long-term data. Maps were prepared showing average precipitation, average streamflow, stream temperature, ground- and surface-water quality, sediment yield, and geology. Recommendations were made for additional study and suggested approaches for continued monitoring in the coalfields areas.moDuring the 1931-75 water years, the minimum discharges for the five major streams that head in the area ranged from about 12,000 to 26,000 acre-feet per year, and the maximum discharges ranged from about 59,000 to 315,000 acre-feet per year. Correlations indicate that 3 years of low-flow records at stream sites in the Wasatch Plateau would allow the development of relationships with long-term sites that can be used to estimate future low-flow records within a standard error of about 20 percent.Most water-quality degradation in streams occurs along the flanks of the Wasatch Plateau and Book Cliffs. In the uplands, dissolved-solids concentrations generally ranged from less than 100 to about 250 milligrams per liter, and in the lowlands, the concentrations ranged from about 250 to more than 6,000 milligrams per liter.Most springs in the Wasatch Plateau and Book Cliffs discharge from the Star Point Sandstone or younger formations, and the water generally contains less than about 1,000 milligrams per liter of dissolved solids. The discharges of 65 springs ranged from about 0.2 to 200 gallons per minute. The Blackhawk Formation, which is the principal coal-bearing formation, produces water in many of the mines. The dissolved-solids concentration in water discharging from springs and mines in the Blackhawk ranged from about 60 to 800 milligrams per liter.In the lowland areas, the Ferron Sandstone Member of the Maneos Shale appears to have the most potential for subsurface development of water of suitable chemical quality for human consumption. Three wells in the Ferron yielded water with dissolved-solids concentrations ranging from about 650 to 1,230 milligrams per liter.

Assessing bisphenol A (BPA) exposure risk from long-term dietary intakes in Taiwan.

PubMed

Chen, Wei-Yu; Shen, Yi-Pei; Chen, Szu-Chieh

2016-02-01

Dietary intake is the major bisphenol A (BPA) exposure route in humans, and is a cause of BPA-related adverse effects. The large-scale exposure risk of humans to BPA through dietary sources in Taiwan is less well studied. The aim of this study was to assess the average daily dose (ADD) and hazardous quotient (HQ) of BPA exposure risk from long-term dietary intake of BPA, as well as BPA concentrations in different age-sex groups in Taiwan. We reanalyzed the BPA concentrations of regular daily food sources (rice, poultry, livestock, seafood, protein, fruits, and vegetables) and used a national dietary survey to estimate the contribution of variance to ADDs and potential human health effect for different age-sex groups. This study found that the daily consumption of chicken, pork/beef, and seafood were estimated to be 33.77 (Male)/22.65 (Female), 91.70 (M)/66.35 (F), and 54.15 (M)/40.78 (F) g/day, respectively. The highest BPA ADD was found in the 6-9 years age group (95% CI=0.0006-0.0027 mg/kg-bw/day), whereas the lowest BPA ADD was in the ≥65 years age group (0.0002-0.0020 mg/kg-bw/day). Based on the latest EFSA guidelines (0.004 mg/kg-bw/day), the 97.5 percentile HQ of BPA intake in different age-sex groups in Taiwan posed no risks through dietary intake. However, a combination of multiple exposure routes and long-term exposure in specific populations may be of concern in the future. Copyright © 2015 Elsevier B.V. All rights reserved.

Effects of ocean acidification on primary production in a coastal North Sea phytoplankton community

PubMed Central

Eberlein, Tim; Wohlrab, Sylke; Rost, Björn; John, Uwe; Bach, Lennart T.; Riebesell, Ulf; Van de Waal, Dedmer B.

2017-01-01

We studied the effect of ocean acidification (OA) on a coastal North Sea plankton community in a long-term mesocosm CO2-enrichment experiment (BIOACID II long-term mesocosm study). From March to July 2013, 10 mesocosms of 19 m length with a volume of 47.5 to 55.9 m3 were deployed in the Gullmar Fjord, Sweden. CO2 concentrations were enriched in five mesocosms to reach average CO2 partial pressures (pCO2) of 760 μatm. The remaining five mesocosms were used as control at ambient pCO2 of 380 μatm. Our paper is part of a PLOS collection on this long-term mesocosm experiment. Here, we here tested the effect of OA on total primary production (PPT) by performing 14C-based bottle incubations for 24 h. Furthermore, photoacclimation was assessed by conducting 14C-based photosynthesis-irradiance response (P/I) curves. Changes in chlorophyll a concentrations over time were reflected in the development of PPT, and showed higher phytoplankton biomass build-up under OA. We observed two subsequent phytoplankton blooms in all mesocosms, with peaks in PPT around day 33 and day 56. OA had no significant effect on PPT, except for a marginal increase during the second phytoplankton bloom when inorganic nutrients were already depleted. Maximum light use efficiencies and light saturation indices calculated from the P/I curves changed simultaneously in all mesocosms, and suggest that OA did not alter phytoplankton photoacclimation. Despite large variability in time-integrated productivity estimates among replicates, our overall results indicate that coastal phytoplankton communities can be affected by OA at certain times of the seasonal succession with potential consequences for ecosystem functioning. PMID:28273107

Long term aerosol and trace gas measurements in Central Amazonia

NASA Astrophysics Data System (ADS)

Artaxo, Paulo; Barbosa, Henrique M. J.; Ferreira de Brito, Joel; Carbone, Samara; Rizzo, Luciana V.; Andreae, Meinrat O.; Martin, Scot T.

2016-04-01

The central region of the Amazonian forest is a pristine region in terms of aerosol and trace gases concentrations. In the wet season, Amazonia is actually one of the cleanest continental region we can observe on Earth. A long term observational program started 20 years ago, and show important features of this pristine region. Several sites were used, between then ATTO (Amazon Tall Tower Observatory) and ZF2 ecological research site, both 70-150 Km North of Manaus, receiving air masses that traveled over 1500 km of pristine tropical forests. The sites are GAW regional monitoring stations. Aerosol chemical composition (OC/EC and trace elements) is being analysed using filters for fine (PM2.5) and coarse mode aerosol as well as Aerodyne ACSM (Aerosol Chemical Speciation Monitors). VOCs are measured using PTR-MS, while CO, O3 and CO2 are routinely measured. Aerosol absorption is being studied with AE33 aethalometers and MAAP (Multi Angle Absorption Photometers). Aerosol light scattering are being measured at several wavelengths using TSI and Ecotech nephelometers. Aerosol size distribution is determined using scanning mobility particle sizer at each site. Lidars measure the aerosol column up to 12 Km providing the vertical profile of aerosol extinction. The aerosol column is measures using AERONET sun photometers. In the wet season, organic aerosol comprises 75-85% of fine aerosol, and sulfate and nitrate concentrations are very low (1-3 percent). Aerosols are dominated by biogenic primary particles as well as SOA from biogenic precursors. Black carbon in the wet season accounts for 5-9% of fine mode aerosol. Ozone in the wet season peaks at 10-12 ppb at the middle of the day, while carbon monoxide averages at 50-80 ppb. Aerosol optical thickness (AOT) is a low 0.05 to 0.1 at 550 nm in the wet season. Sahara dust transport events sporadically enhance the concentration of soil dust aerosols and black carbon. In the dry season (August-December), long range transported biomass burning alters atmospheric composition very significantly. AOT can reach values as high as 2-3 at 550 nm, and concentrations of aerosol species and trace gases are strongly enriched.

Long-term results with percutaneous interspinous process devices in the treatment of neurogenic intermittent claudication.

PubMed

Fransen, Patrick

2017-12-01

Neurogenic intermittent claudication (NIC) is the main symptom of degenerative lumbar spinal stenosis. Percutaneous interspinous process decompression devices (IPDs) have been designed as an alternative therapy to conservative treatment and to open decompressive surgery for patients suffering from NIC. Initial short-term results were encouraging. We present the long-term results of a group of patients that we followed to provide insight on long-term outcomes and effectiveness of this technique compared to other decompression methods. Fifteen patients operated for NIC by implantation of percutaneous IPDs have been prospectively monitored for reoperations or complications. Follow-up (FU) was interrupted if the patient was reoperated. Results were considered poor if the patient had to be reoperated at any stage of the FU or if the treatment failed to alleviate the pain after 6 months. Results were considered average if the patient still suffered some pain but did not require reoperation. The patients were followed up to 7 years after the initial surgery. The mean length of the FU was 3.53 years and all patients could be followed. At the end of the FU, the results were good in only 20.0% (3/15), average in 13.3% (2/15) and poor in 66.7% (10/15). Despite initial satisfactory results, long-term FU is disappointing, with 80% poor or average results. The long-term reoperation rate is high (66.6%), increases over time and is higher than after implantation of IPDs for decompression augmentation. Although this technique is simple and safe, its effectiveness seems short-lived. We recommend cautious use and informing patients about the risk of relatively early failure and recurrence.

On the construction, comparison, and variability of airsheds for interpreting semivolatile organic compounds in passively sampled air.

PubMed

Westgate, John N; Wania, Frank

2011-10-15

Air mass origin as determined by back trajectories often aids in explaining some of the short-term variability in the atmospheric concentrations of semivolatile organic contaminants. Airsheds, constructed by amalgamating large numbers of back trajectories, capture average air mass origins over longer time periods and thus have found use in interpreting air concentrations obtained by passive air samplers. To explore some of their key characteristics, airsheds for 54 locations on Earth were constructed and compared for roundness, seasonality, and interannual variability. To avoid the so-called "pole problem" and to simplify the calculation of roundness, a "geodesic grid" was used to bin the back-trajectory end points. Departures from roundness were seen to occur at all latitudes and to correlate significantly with local slope but no strong relationship between latitude and roundness was revealed. Seasonality and interannual variability vary widely enough to imply that static models of transport are not sufficient to describe the proximity of an area to potential sources of contaminants. For interpreting an air measurement an airshed should be generated specifically for the deployment time of the sampler, especially when investigating long-term trends. Samples taken in a single season may not represent the average annual atmosphere, and samples taken in linear, as opposed to round, airsheds may not represent the average atmosphere in the area. Simple methods are proposed to ascertain the significance of an airshed or individual cell. It is recommended that when establishing potential contaminant source regions only end points with departure heights of less than ∼700 m be considered.

When fed foods with similar palatability, healthy adult dogs and cats choose different macronutrient compositions.

PubMed

Hall, Jean A; Vondran, Jodi C; Vanchina, Melissa A; Jewell, Dennis E

2018-05-17

Dogs and cats make short-term food choices based on palatability. We hypothesized that if palatability were masked, long-term food choices would be based on physiologic requirements, and circulating metabolite concentrations would reflect those choices. Four experimental foods with similar palatability, but varying in macronutrient composition, were prepared for healthy adult dogs (n=17) and cats (n=27). Food 1 was high protein; Food 2 was high fat; Food 3 was high carbohydrates; and Food 4 was balanced for macronutrients. By choosing any combination of foods, dogs and cats could individually set their macronutrient intake. Plasma metabolomic profiles were determined at baseline and after animals had consumed their food intake of choice for 28 days. Based on food intake calculations over 28 days, dogs on average chose to consume most of their calories from fat (41.1±4.3%) and then carbohydrate (35.8±3.7%), whereas cats on average chose to consume most of their calories from carbohydrate (43.1±4.0%) and then protein (30.3±3.9%; all P <0.001). Age and lean or fat body mass also influenced protein intake. Younger, leaner cats consumed more protein compared with older cats, whereas younger leaner dogs consumed less protein compared with dogs having more fat body mass. Older cats with moderate protein intake had lower circulating docosahexaenoic acid (DHA) concentrations as well as higher concentrations of sulfated microbial catabolic products compared with younger, leaner cats. In summary, when fed foods with similar palatability, dogs and cats consume different macronutrient compositions, and concentrations of circulating metabolites in cats reflect food choices. © 2018. Published by The Company of Biologists Ltd.

Long-Term Effects of Ambient PM2.5 on Hypertension and Blood Pressure and Attributable Risk Among Older Chinese Adults.

PubMed

Lin, Hualiang; Guo, Yanfei; Zheng, Yang; Di, Qian; Liu, Tao; Xiao, Jianpeng; Li, Xing; Zeng, Weilin; Cummings-Vaughn, Lenise A; Howard, Steven W; Vaughn, Michael G; Qian, Zhengmin Min; Ma, Wenjun; Wu, Fan

2017-05-01

Long-term exposure to ambient fine particulate pollution (PM 2.5 ) has been associated with cardiovascular diseases. Hypertension, a major risk factor for cardiovascular diseases, has also been hypothesized to be linked to PM 2.5 However, epidemiological evidence has been mixed. We examined long-term association between ambient PM 2.5 and hypertension and blood pressure. We interviewed 12 665 participants aged 50 years and older and measured their blood pressures. Annual average PM 2.5 concentrations were estimated for each community using satellite data. We applied 2-level logistic regression models to examine the associations and estimated hypertension burden attributable to ambient PM 2.5 For each 10 μg/m 3 increase in ambient PM 2.5 , the adjusted odds ratio of hypertension was 1.14 (95% confidence interval, 1.07-1.22). Stratified analyses found that overweight and obesity could enhance the association, and consumption of fruit was associated with lower risk. We further estimated that 11.75% (95% confidence interval, 5.82%-18.53%) of the hypertension cases (corresponding to 914, 95% confidence interval, 453-1442 cases) could be attributable to ambient PM 2.5 in the study population. Findings suggest that long-term exposure to ambient PM 2.5 might be an important risk factor of hypertension and is responsible for significant hypertension burden in adults in China. A higher consumption of fruit may mitigate, whereas overweight and obesity could enhance this effect. © 2017 American Heart Association, Inc.

Contrasted spatial and long-term trends in precipitation chemistry and deposition fluxes at rural stations in France

NASA Astrophysics Data System (ADS)

Pascaud, A.; Sauvage, S.; Coddeville, P.; Nicolas, M.; Croisé, L.; Mezdour, A.; Probst, A.

2016-12-01

The long-distance effect of atmospheric pollution on ecosystems has led to the conclusion of international agreements to regulate atmospheric emissions and monitor their impact. This study investigated variations in atmospheric deposition chemistry in France using data gathered from three different monitoring networks (37 stations) over the period from 1995 to 2007. Despite some methodological differences (e.g. type of collector, frequency of sampling and analysis), converging results were found in spatial variations, seasonal patterns and temporal trends. With regard to spatial variations, the mean annual pH in particular ranged from 4.9 in the north-east to 5.8 in the south-east. This gradient was related to the concentration of NO3- and non-sea-salt SO42- (maximum volume-weighted mean of 38 and 31 μeq l-1 respectively) and of acid-neutralising compounds such as non-sea-salt Ca2+ and NH4+. In terms of seasonal variations, winter and autumn pH were linked to lower acidity neutralisation than during the warm season. The temporal trends in atmospheric deposition varied depending on the chemical species and site location. The most significant and widespread trend was the decrease in non-sea-salt SO42- concentrations (significant at 65% of the stations). At the same time, many stations showed an increasing trend in annual pH (+0.3 on average for 16 stations). These two trends are probably due to the reduction in SO2 emissions that has been imposed in Europe since the 1980s. Temporal trends in inorganic N concentrations were rather moderate and not consistent with the trends reported in emission estimates. Despite the reduction in NOx emissions, NO3- concentrations in atmospheric deposition remained mostly unchanged or even increased at three stations (+0.43 μeq l-1 yr-1 on average). In contrast NH4+ concentrations in atmospheric deposition decreased at several stations located in western and northern areas, while the estimates of NH3 emissions remained fairly stable. The decrease in non-sea-salt SO42- and NH4+ concentrations was mainly due to a decrease in summer values and can in part be related to a dilution process since the precipitation amount showed an increasing trend during the summer. Furthermore, increasing trends in NO3- concentrations in the spring and, to a lesser extent, in NH4+ concentrations suggested that other atmospheric physicochemical processes should also be taken into account.

Characterizing depth-dependent refractive index of articular cartilage subjected to mechanical wear or enzymic degeneration

NASA Astrophysics Data System (ADS)

Wang, Kuyu; Wu, Jianping; Day, Robert; Kirk, Thomas Brett; Hu, Xiaozhi

2016-09-01

Utilizing a laser scanning confocal microscope system, the refractive indices of articular cartilage (AC) with mechanical or biochemical degenerations were characterized to investigate whether potential correlations exist between refractive index (RI) and cartilage degeneration. The cartilage samples collected from the medial femoral condyles of kangaroo knees were mechanically degenerated under different loading patterns or digested in trypsin solution with different concentrations. The sequences of RI were then measured from cartilage surface to deep region and the fluctuations of RI were quantified considering combined effects of fluctuating frequency and amplitude. The compositional and microstructural alterations of cartilage samples were assessed with histological methods. Along with the loss of proteoglycans, the average RI of cartilage increased and the local fluctuation of RI became stronger. Short-term high-speed test induced little influence to both the depth fluctuation and overall level of RI. Long-term low-speed test increased the fluctuation of RI but the average RI was barely changed. The results substantially demonstrate that RI of AC varies with both compositional and structural alterations and is potentially an indicator for the degeneration of AC.

Exercise mitigates cumulative associations between stress and BMI in girls age 10 to 19.

PubMed

Puterman, Eli; Prather, Aric A; Epel, Elissa S; Loharuka, Sheila; Adler, Nancy E; Laraia, Barbara; Tomiyama, A Janet

2016-02-01

Long-term psychological stress is associated with BMI increases in children as they transition to adulthood, whereas long-term maintenance of physical activity can slow excess weight gain. We hypothesized that in addition to these main effects, long-term physical activity mitigates the relationship between long-term stress and BMI increase. The NHLBI Growth and Health Study enrolled 2,379 10-year-old Black and White girls, following them annually for 10 measurement points. Growth curve modeling captured the dynamics of BMI, measured yearly, and stress and physical activity, measured at varying years. At average levels of activity and stress, with all covariates remaining fixed, average BMI at baseline was 19.74 (SE = 0.38) and increased 0.64 BMI (SE = 0.01, p < .001) units every year. However, this increase in BMI significantly varied as a function of cumulative stress and physical activity. Slower BMI gain occurred in those girls who were less stressed and more active (0.62 BMI units/year, SE = .02, p < .001), whereas the most rapid and largest growth occurred in girls who were more stressed and less active (0.92 BMI units/year, SE = .02, p < .001). Racial identification did not alter these effects. As hypothesized, in girls who maintained long-term activity, BMI growth was mitigated, even when reporting high long-term stress, compared with less physically active girls. This study adds to a converging literature in which physical activity, a modifiable prevention target, functions to potentially limit the damaging health effects of long-term psychological stress. (c) 2016 APA, all rights reserved).

Exercise mitigates cumulative associations between stress and BMI in girls age 10–19

PubMed Central

Prather, Aric A.; Epel, Elissa S.; Loharuka, Sheila; Adler, Nancy E.; Laraia, Barbara

2015-01-01

Objective Long-term psychological stress is associated with BMI increases in children as they transition to adulthood, while long-term maintenance of physical activity can slow excess weight gain. We hypothesized that in addition to these main effects, long-term physical activity mitigates the relationship between long-term stress and BMI increase. Methods The NHLBI Growth and Health Study enrolled 2,379 10-year-old Black and White girls, following them annually for 10 measurement points. Growth curve modeling captured the dynamics of BMI, measured yearly, and stress and physical activity, measured every other year. Results At average levels of activity and stress, with all covariates remaining fixed, average BMI at baseline was 19.74 (SE = 0.38) and increased 0.64 BMI (SE= 0.01, p < .001) units every year. However, this increase in BMI significantly varied as a function of cumulative stress and physical activity. Slower BMI gain occurred in those girls who were less stressed and more active (0.62 BMI units/year, SE= .02, p < .001), whereas the most rapid and largest growth occurred in girls who were the more stressed and less active (0.92 BMI units/year, SE= .02, p < .001). Racial identification did not alter these effects. Conclusions As hypothesized, in girls who maintained long-term activity, BMI growth was mitigated, even when reporting high long-term stress, compared to less physically active girls. This study adds to a converging literature in which physical activity, a modifiable prevention target, functions to potentially limit the damaging health effects of long-term psychological stress. PMID:26301595

Cost analysis and facility reimbursement in the long-term health care industry.

PubMed Central

Ullmann, S G

1984-01-01

This article examines costs and develops a system of prospective reimbursement for the industry committed to long-term health care. Together with estimates of average cost functions--for purposes of determining those factors affecting the costs of long-term health care, the author examines in depth the cost effects of patient mix and facility quality. Policy implications are indicated. The article estimates cost savings and predicted improvements in facility performance resulting from adoption of a prospective reimbursement system. PMID:6427138

Improved Knowledge Base would be Helpful in Reaching Policy Decisions on Providing Long-Term, In-Home Services for the Elderly.

DTIC Science & Technology

1981-10-26

per month required to maintain such persons in an intermediate care facility . However, the clients eligible for long-term, in-home care were also...assistance under the Food Stamp program. When such clients enter an intermediate care facility , some of their public financial assistance is used to... intermediate care facility was not significant on the average, considering all public assistance costs. For our sample of 30 clients in Oklahoma’s long- term, in

Consider long-term care as service alternative.

PubMed

Loria, L S

1987-04-01

The increasing demand for elderly care services, pressures on inpatient average length of stay and payment levels, and potential financial rewards from providing additional services, makes long-term care look attractive to hospitals. Long-term care, however, is not for every hospital. Before deciding to establish long-term care services, management should examine how the service fits within the hospital's strategic plan. The action plan below provides guidance in evaluating a decision to use hospital facilities for long-term care. Examine how long-term care services fit within the hospital's strategic plan. Study area demographics and competitors to assess the need and supply of long-term care services. Survey the medical staff, consumers and payers to determine attitudes, perceptions and interests regarding long-term care services. Develop a facility plan that identifies areas of excess capacity that can be most easily converted into long-term care with minimal effects on hospital operations. Prepare a financial feasibility analysis of the contribution margin and return on investment attributable to long-term care services. Include an impact analysis on hospital operations. Establish a management task force to develop a detailed implementation plan including assigned individual responsibilities and related timetable. Develop an effective marketing plan designed to generate increased patient market share.

Kinetic and microbiological characterization of aerobic granules performing partial nitritation of a low-strength wastewater at 10 °C.

PubMed

Reino, Clara; Suárez-Ojeda, María Eugenia; Pérez, Julio; Carrera, Julián

2016-09-15

A granular airlift reactor enriched in ammonia oxidizing bacteria (AOB) was operated at 10 °C performing stable partial nitritation in the long-term. The reactor treated a synthetic low-strength influent during 250 days with an average nitrogen loading rate of 0.63 ± 0.06 g N L(-1) d(-1). Nitrate production was barely detected, being the average concentration in the effluent of 0.6 ± 0.3 mg N-NO3 L(-1). Furthermore, a suitable effluent for a subsequent reactor performing the anammox process was achieved. A maximum specific growth rate as high as 0.63 ± 0.05 d(-1) was determined by performing kinetic experiments with the granular sludge in a chemostat and fitting the results to the Monod model. Pyrosequencing analysis showed a high enrichment in AOB (41 and 65% of the population were identified as Nitrosomonas genus on day 98 and 233, respectively) and an effective repression of nitrite oxidizing bacteria in the long-term. Pyrosequencing analysis also identified the coexistence of nitrifying bacteria and heterotrophic psychrotolerant microorganisms in the granular sludge. Some psychrotolerant microorganisms are producers of cryoprotective extracellular polymeric substances that could explain the better survival of the whole consortia at cold temperatures. Copyright © 2016 Elsevier Ltd. All rights reserved.

The influence of a tilt training programme on the renin-angiotensin-aldosterone system activity in patients with vasovagal syncope.

PubMed

Gajek, Jacek; Zyśko, Dorota; Krzemińska, Sylwia; Mazurek, Walentyna

2009-08-01

We assessed the influence of short-term and long-term tilt training on the activity of the renin-angiotensin-aldosterone system (RAAS) in vasovagal patients. Thirty-nine patients (28 F, 11 M) aged 39.7 +/- 11.2 years with a history of vasovagal syncope and a positive head-up tilt test (HUT) were studied. Blood samples for plasma renin activity (PRA) and aldosterone (ALDO) concentration were drawn at the baseline, immediately after HUT and 10 min after HUT, during the diagnostic, the negative short-term (2-5 days) follow-up HUT and long-term (1-3 months) follow-up HUT. Tilt training was started after diagnostic HUT. In diagnostic HUT, PRA increased significantly immediately after HUT comparing to the baseline, during recovery the values did not change. ALDO concentration increased after HUT comparing to baseline and further increased during recovery. After short-term tilt training, PRA and ALDO concentrations did not significantly change compared to their corresponding values in diagnostic HUT. After long-term tilt training, PRA did not significantly change compared to the values in the diagnostic and short-term follow-up HUT. ALDO concentration also did not change significantly at the baseline and immediately after HUT, and 10 min after HUT ALDO concentration was significantly lower than after diagnostic HUT. Tilt training changes the response of RAAS to the prolonged orthostasis in vasovagal patients. The coupling between PRA and ALDO after diagnostic HUT has been found to be altered and the physiological relationship was restored after long-term tilt training. The beneficial effect of tilt training depends partially on changed RAAS activation.

Geothermal production and reduced seismicity: Correlation and proposed mechanism

NASA Astrophysics Data System (ADS)

Cardiff, Michael; Lim, David D.; Patterson, Jeremy R.; Akerley, John; Spielman, Paul; Lopeman, Janice; Walsh, Patrick; Singh, Ankit; Foxall, William; Wang, Herbert F.; Lord, Neal E.; Thurber, Clifford H.; Fratta, Dante; Mellors, Robert J.; Davatzes, Nicholas C.; Feigl, Kurt L.

2018-01-01

At Brady Hot Springs, a geothermal field in Nevada, heated fluids have been extracted, cooled, and re-injected to produce electrical power since 1992. Analysis of daily pumping records and catalogs of microseismicity between 2010 and 2015 indicates a statistically significant correlation between days when the daily volume of production was at or above its long-term average rate and days when no seismic event was detected. Conversely, shutdowns in pumping for plant maintenance correlate with increased microseismicity. We hypothesize that the effective stress in the subsurface has adapted to the long-term normal operations (deep extraction) at the site. Under this hypothesis, extraction of fluids inhibits fault slip by increasing the effective stress on faults; in contrast, brief pumping cessations represent times when effective stress is decreased below its long-term average, increasing the likelihood of microseismicity.

Evaluation of outdoor human thermal sensation of local climate zones based on long-term database

NASA Astrophysics Data System (ADS)

Unger, János; Skarbit, Nóra; Gál, Tamás

2018-02-01

This study gives a comprehensive picture on the diurnal and seasonal general outdoor human thermal sensation levels in different urban quarters based on long-term (almost 3 years) data series from urban and rural areas of Szeged, Hungary. It is supplemented with a case study dealing with an extreme heat wave period which is more and more frequent in the last decades in the study area. The intra-urban comparison is based on a thermal aspect classification of the surface, namely, the local climate zone (LCZ) system, on an urban meteorological station network and on the utilization of the physiologically equivalent temperature (PET) comfort index with categories calibrated to the local population. The selected stations represent sunlit areas well inside the LCZ areas. The results show that the seasonal and annual average magnitudes of the thermal load exerted by LCZs in the afternoon and evening follow their LCZ numbers. It is perfectly in line with the LCZ concept originally concentrating only on air temperature ( T air) differences between the zones. Our results justified the subdivision of urban areas into LCZs and give significant support to the application possibilities of the LCZ concept as a broader term covering different thermal phenomena.

Spatial and temporal changes in the structure of groundwater nitrate concentration time series (1935 1999) as demonstrated by autoregressive modelling

NASA Astrophysics Data System (ADS)

Jones, A. L.; Smart, P. L.

2005-08-01

Autoregressive modelling is used to investigate the internal structure of long-term (1935-1999) records of nitrate concentration for five karst springs in the Mendip Hills. There is a significant short term (1-2 months) positive autocorrelation at three of the five springs due to the availability of sufficient nitrate within the soil store to maintain concentrations in winter recharge for several months. The absence of short term (1-2 months) positive autocorrelation in the other two springs is due to the marked contrast in land use between the limestone and swallet parts of the catchment, rapid concentrated recharge from the latter causing short term switching in the dominant water source at the spring and thus fluctuating nitrate concentrations. Significant negative autocorrelation is evident at lags varying from 4 to 7 months through to 14-22 months for individual springs, with positive autocorrelation at 19-20 months at one site. This variable timing is explained by moderation of the exhaustion effect in the soil by groundwater storage, which gives longer residence times in large catchments and those with a dominance of diffuse flow. The lags derived from autoregressive modelling may therefore provide an indication of average groundwater residence times. Significant differences in the structure of the autocorrelation function for successive 10-year periods are evident at Cheddar Spring, and are explained by the effect the ploughing up of grasslands during the Second World War and increased fertiliser usage on available nitrogen in the soil store. This effect is moderated by the influence of summer temperatures on rates of mineralization, and of both summer and winter rainfall on the timing and magnitude of nitrate leaching. The pattern of nitrate leaching also appears to have been perturbed by the 1976 drought.

Short-term effect of ambient air pollution on COPD mortality in four Chinese cities

NASA Astrophysics Data System (ADS)

Meng, Xia; Wang, Cuicui; Cao, Dachun; Wong, Chit-Ming; Kan, Haidong

2013-10-01

Ambient air pollution has been associated with increased mortality and morbidity; however, few studies have examined the short-term effect of air pollution specifically on chronic obstructive pulmonary disease (COPD), which is an important cause of mortality and morbidity world wide. In this analysis, we examined the associations between daily air pollution levels [particulate matter less than 10 microns in aerodynamic diameter (PM10), sulfur dioxide (SO2) and nitrogen dioxide (NO2)] and COPD mortality in four Chinese cities. We used Poisson regression models with natural spline smoothing functions to adjust for long-term and seasonal trends of COPD mortality, as well as other time-varying covariates. We did a meta-analysis to obtain the 4-city average estimates. Air pollution (PM10, SO2, and NO2) was found to be associated with increased risk of COPD mortality in these four cities. Using the random-effects model, an increase of 10 μg m-3 of 2-day moving average concentrations of PM10, SO2 and NO2 corresponded to a 0.78% (95% CI, 0.13-1.42), 1.30% (95% CI, 0.61-1.99), and 1.78% (95% CI, 1.10-2.46) increase of COPD mortality, respectively. The concentration-response curves indicated linear associations without threshold. Only NO2 remained significant in the multi-pollutant models. To our knowledge, this is the first multi-city study in Asian developing region to report the short-term effect of air pollution on COPD mortality. Our results contribute to very limited data on the effects of air pollution on COPD mortality for high exposure settings typical in developing countries.

A COMPARISON OF WINTER SHORT-TERM AND ANNUAL AVERAGE RADON MEASUREMENTS IN BASEMENTS OF A RADON-PRONE REGION AND EVALUATION OF FURTHER RADON TESTING INDICATORS

PubMed Central

Barros, Nirmalla G.; Steck, Daniel J.; Field, R. William

2014-01-01

The primary objective of this study was to investigate the temporal variability between basement winter short-term (7 to 10 days) and basement annual radon measurements. Other objectives were to test the short-term measurement’s diagnostic performance at two reference levels and to evaluate its ability to predict annual average basement radon concentrations. Electret ion chamber (short-term) and alpha track (annual) radon measurements were obtained by trained personnel in Iowa residences. Overall, the geometric mean of the short-term radon concentrations (199 Bq m−3) was slightly greater than the geometric mean of the annual radon concentrations (181 Bq m−3). Short-term tests incorrectly predicted that the basement annual radon concentrations would be below 148 Bq m−3 12% of the time and 2% of the time at 74 Bq m−3. The short-term and annual radon concentrations were strongly correlated (r=0.87, p<0.0001). The foundation wall material of the basement was the only significant factor to have an impact on the absolute difference between the short-term and annual measurements. The findings from this study provide evidence of a substantially lower likelihood of obtaining a false negative result from a single short-term test in a region with high indoor radon potential when the reference level is lowered to 74 Bq m−3. PMID:24670901

Roadmap to Long-Term Monitoring Optimization

EPA Pesticide Factsheets

This roadmap focuses on optimization of established long-term monitoring programs for groundwater. Tools and techniques discussed concentrate on methods for optimizing the monitoring frequency and spatial (three-dimensional) distribution of wells ...

Reduced Ultrafine Particle Concentration in Urban Air: Changes in Nucleation and Anthropogenic Emissions.

PubMed

Saha, Provat K; Robinson, Ellis S; Shah, Rishabh U; Zimmerman, Naomi; Apte, Joshua S; Robinson, Allen L; Presto, Albert A

2018-06-19

Nucleation is an important source of ambient ultrafine particles (UFP). We present observational evidence of the changes in the frequency and intensity of nucleation events in urban air by analyzing long-term particle size distribution measurements at an urban background site in Pittsburgh, Pennsylvania during 2001-2002 and 2016-2017. We find that both frequency and intensity of nucleation events have been reduced by 40-50% over the past 15 years, resulting in a 70% reduction in UFP concentrations from nucleation. On average, the particle growth rates are 30% slower than 15 years ago. We attribute these changes to dramatic reductions in SO 2 (more than 90%) and other pollutant concentrations. Overall, UFP concentrations in Pittsburgh have been reduced by ∼48% in the past 15 years, with a ∼70% reduction in nucleation, ∼27% in weekday local sources (e.g., weekday traffic), and 49% in the regional background. Our results highlight that a reduction in anthropogenic emissions can considerably reduce nucleation events and UFP concentrations in a polluted urban environment.

Sediment concentrations and loads in the Loxahatchee River estuary, Florida, 1980-82

USGS Publications Warehouse

Sonntag, Wayne H.; McPherson, Benjamin F.

1984-01-01

This study was conducted to estimate the magnitude of sediment loads and the general spatial and temporal patterns of sediment transport in the Loxahatchee River estuary, Florida. Mean concentrations of suspended sediment generally were higher in the Jupiter Inlet area than in the remainder of the embayment area. Concentrations of suspended sediment varied with season and weather conditions. Concentrations in selected tributaries following Tropical Storm Dennis in August 1981 immediately increased as much as 16 times over concentrations before the storm. Suspended-sediment loads from the tributaries were also highly seasonal and storm related. During a 61-day period of above-average rainfall that included Tropical Storm Dennis, 5 major tributaries discharged 926 tons (short) of suspended sediment to the estuary, accounting for 74 percent of the input for the 1981 water year and 49 percent of the input for the 20-month study period. Suspended-sediment loads at Jupiter Inlet and at the mouth of the estuary embayment on both incoming and outgoing tides far exceeded tributary loads, but the direction of long-term, net tidal transport was not determined. (USGS)

Species richness inside and outside long-term exclosures

Treesearch

W. A. Laycock; D. L. Bartos; K. D. Klement

2004-01-01

Recent environmental literature contains claims that livestock grazing has caused reduction in species diversity on Western rangelands. Data of species richness (number of species) is presented from inside and outside 24 long-term exclosures in Montana, Utah, and Wyoming. For the average of all exclosures there was no difference between species richness inside and...

Evaluating methods for estimating space-time paths of individuals in calculating long-term personal exposure to air pollution

NASA Astrophysics Data System (ADS)

Schmitz, Oliver; Soenario, Ivan; Vaartjes, Ilonca; Strak, Maciek; Hoek, Gerard; Brunekreef, Bert; Dijst, Martin; Karssenberg, Derek

2016-04-01

Air pollution is one of the major concerns for human health. Associations between air pollution and health are often calculated using long-term (i.e. years to decades) information on personal exposure for each individual in a cohort. Personal exposure is the air pollution aggregated along the space-time path visited by an individual. As air pollution may vary considerably in space and time, for instance due to motorised traffic, the estimation of the spatio-temporal location of a persons' space-time path is important to identify the personal exposure. However, long term exposure is mostly calculated using the air pollution concentration at the x, y location of someone's home which does not consider that individuals are mobile (commuting, recreation, relocation). This assumption is often made as it is a major challenge to estimate space-time paths for all individuals in large cohorts, mostly because limited information on mobility of individuals is available. We address this issue by evaluating multiple approaches for the calculation of space-time paths, thereby estimating the personal exposure along these space-time paths with hyper resolution air pollution maps at national scale. This allows us to evaluate the effect of the space-time path and resulting personal exposure. Air pollution (e.g. NO2, PM10) was mapped for the entire Netherlands at a resolution of 5×5 m2 using the land use regression models developed in the European Study of Cohorts for Air Pollution Effects (ESCAPE, http://escapeproject.eu/) and the open source software PCRaster (http://www.pcraster.eu). The models use predictor variables like population density, land use, and traffic related data sets, and are able to model spatial variation and within-city variability of annual average concentration values. We approximated space-time paths for all individuals in a cohort using various aggregations, including those representing space-time paths as the outline of a persons' home or associated parcel of land, the 4 digit postal code area or neighbourhood of a persons' home, circular areas around the home, and spatial probability distributions of space-time paths during commuting. Personal exposure was estimated by averaging concentrations over these space-time paths, for each individual in a cohort. Preliminary results show considerable differences of a persons' exposure using these various approaches of space-time path aggregation, presumably because air pollution shows large variation over short distances.

The relationship between interannual and long-term cloud feedbacks

DOE PAGES

Zhou, Chen; Zelinka, Mark D.; Dessler, Andrew E.; ...

2015-12-11

The analyses of Coupled Model Intercomparison Project phase 5 simulations suggest that climate models with more positive cloud feedback in response to interannual climate fluctuations also have more positive cloud feedback in response to long-term global warming. Ensemble mean vertical profiles of cloud change in response to interannual and long-term surface warming are similar, and the ensemble mean cloud feedback is positive on both timescales. However, the average long-term cloud feedback is smaller than the interannual cloud feedback, likely due to differences in surface warming pattern on the two timescales. Low cloud cover (LCC) change in response to interannual andmore » long-term global surface warming is found to be well correlated across models and explains over half of the covariance between interannual and long-term cloud feedback. In conclusion, the intermodel correlation of LCC across timescales likely results from model-specific sensitivities of LCC to sea surface warming.« less

Sources, concentrations, and risks of naphthalene in indoor and outdoor air.

PubMed

Batterman, S; Chin, J-Y; Jia, C; Godwin, C; Parker, E; Robins, T; Max, P; Lewis, T

2012-08-01

Naphthalene is a ubiquitous pollutant, and very high concentrations are sometimes encountered indoors when this chemical is used as a pest repellent or deodorant. This study describes the distribution and sources of vapor-phase naphthalene concentrations in four communities in southeast Michigan, USA. Outdoors, naphthalene was measured in the communities and at a near-road site. Indoors, naphthalene levels were characterized in 288 suburban and urban homes. The median outdoor concentration was 0.15 μg/m(3), and a modest contribution from rush-hour traffic was noted. The median indoor long-term concentration was 0.89 μg/m(3), but concentrations were extremely skewed and 14% of homes exceeded 3 μg/m(3), the chronic reference concentration for non-cancer effects, 8% exceeded 10 μg/m(3), and levels reached 200 μg/m(3). The typical excess individual lifetime cancer risk was about 10(-4) and reached 10(-2) in some homes. Important sources include naphthalene's use as a pest repellent and deodorant, migration from attached garages and, to lesser extents, cigarette smoke and vehicle emissions. Excessive use as a repellent caused the highest concentrations. Naphthalene presents high risks in a subset of homes, and policies and actions to reduce exposures, for example, sales bans or restrictions, improved labeling, and consumer education, should be considered. Long-term average concentrations of naphthalene in most homes fell into the 0.2-1.7 μg/m(3) range reported as representative in earlier studies. The highly skewed distribution of concentrations results in a subset of homes with elevated concentrations and health risks that greatly exceed US EPA and World Health Organization (WHO) guidelines. The most important indoor source is the use of naphthalene as a pest repellant or deodorant; secondary sources include presence of an attached garage, cigarette smoking, and outdoor sources. House-to-house variation was large, reflecting differences among the residences and naphthalene use practices. Stronger policies and educational efforts are needed to eliminate or modify indoor usage practices of this chemical. © 2011 John Wiley & Sons A/S.

Long-Term Planetary Habitability and the Carbonate-Silicate Cycle.

PubMed

Rushby, Andrew J; Johnson, Martin; Mills, Benjamin J W; Watson, Andrew J; Claire, Mark W

2018-05-01

The potential habitability of an exoplanet is traditionally assessed by determining whether its orbit falls within the circumstellar "habitable zone" of its star, defined as the distance at which water could be liquid on the surface of a planet (Kopparapu et al., 2013 ). Traditionally, these limits are determined by radiative-convective climate models, which are used to predict surface temperatures at user-specified levels of greenhouse gases. This approach ignores the vital question of the (bio)geochemical plausibility of the proposed chemical abundances. Carbon dioxide is the most important greenhouse gas in Earth's atmosphere in terms of regulating planetary temperature, with the long-term concentration controlled by the balance between volcanic outgassing and the sequestration of CO 2 via chemical weathering and sedimentation, as modulated by ocean chemistry, circulation, and biological (microbial) productivity. We developed a model that incorporates key aspects of Earth's short- and long-term biogeochemical carbon cycle to explore the potential changes in the CO 2 greenhouse due to variance in planet size and stellar insolation. We find that proposed changes in global topography, tectonics, and the hydrological cycle on larger planets result in proportionally greater surface temperatures for a given incident flux. For planets between 0.5 and 2 R ⊕ , the effect of these changes results in average global surface temperature deviations of up to 20 K, which suggests that these relationships must be considered in future studies of planetary habitability. Key Words: Planets-Atmospheres-Carbon dioxide-Biogeochemistry. Astrobiology 18, 469-480.

Characteristics of atmospheric ammonia and its relationship with vehicle emissions in a megacity in China

NASA Astrophysics Data System (ADS)

Wang, Ruyu; Ye, Xingnan; Liu, Yuxuan; Li, Haowen; Yang, Xin; Chen, Jianmin; Gao, Wei; Yin, Zi

2018-06-01

Atmospheric ammonia plays an important role in haze formation in East China. In this study, long-term measurements of NH3 concentrations were implemented at urban, suburban, and tunnel sites in Shanghai, the largest city in East China. The average monthly ammonia concentrations at the urban site varied from 3.7 ppb to 14.5 ppb and exhibited the highest levels in summer and lowest levels in winter, indicating that the biological emissions and agriculture in the surrounding areas are important contributors. The suburban NH3 levels were significantly higher in autumn compared to those at the urban site, indicating the important contribution of agricultural activities. Regardless of the season, the difference of NH3 concentrations between the tunnel and urban sites remained almost constant. On average, the tunnel NH3 level was three times higher than that of the nearby urban site, indicating strong vehicle NH3 emissions in the tunnel. The tunnel NH3 levels on weekdays were comparable to those on weekends, a result that was in agreement with the daily average traffic volume. It was estimated that the vehicle emissions contributed 12.6-24.6% of the atmospheric NH3 in the urban area and 3.8-7.5% for the whole area of Shanghai. Our results suggest that vehicle NH3 emissions should be considered, although agricultural emissions are still more important for mitigating severe haze pollution during wintertime in the megacities of China.

Lipid concentrations in Lake Michigan fishes: Seasonal, spatial, ontogenetic, and long-term trends

USGS Publications Warehouse

Madenjian, Charles P.; Elliott, Robert F.; DeSorcie, Timothy J.; Stedman, Ralph M.; O'Connor, Daniel V.; Rottiers, Donald V.

2000-01-01

Lipid concentrations were measured in seven species of fish from several locations in Lake Michigan during spring, summer, and fall in 1994 to 1995. Adult alewife (Alosa pseudoharengus) and age-2 coho salmon (Oncorhynchus kisutch) exhibited pronounced seasonal changes in lipid content. Adult alewives averaged 7.4% lipid, on a wet weight basis, during spring (May), 2.6% in summer (July), and 12.2% in fall (late September through October). Spring lipid concentration was low in age-2 coho salmon, averaging only 1.9%, then increased to 7.8% during summer and decreased to 4.5% by fall. In contrast, lipid content in adult bloater (Coregonus hoyi) was relatively constant with respect to season, ranging between 10.6% and 12.4% during the year. Lipid concentration increased with fish size for all species except rainbow smelt (Osmerus mordax). Although deepwater sculpin (Myoxocephalus thompsoni) were considerably larger than slimy sculpin (Cottus cognatus) (mean total length of 117 mm vs 68 mm), mean lipid content of deepwater sculpin (7.6%) was only slightly higher than that for slimy sculpin (6.6%). Comparison of lipid concentrations from this study with previous studies indicated that lipid concentration in lake trout (Salvelinus namaycush) and alewives in Lake Michigan did not change significantly from 1969–1971 to 1994–1995. Lipid concentration in large (about 250 mm total length) adult bloaters near Saugatuck (along the southeastern shore of the lake) decreased from 23.3% in 1980 to 11.9% in 1986, but showed no significant change between 1986 and 1994–1995.

A depth-averaged 2-D shallow water model for breaking and non-breaking long waves affected by rigid vegetation

USDA-ARS?s Scientific Manuscript database

This paper presents a depth-averaged two-dimensional shallow water model for simulating long waves in vegetated water bodies under breaking and non-breaking conditions. The effects of rigid vegetation are modelled in the form of drag and inertia forces as sink terms in the momentum equations. The dr...

Long-term orbit prediction for the Venus Radar Mapper Mission using an averaging method

NASA Technical Reports Server (NTRS)

Kwok, J. H.

1984-01-01

A set of singly averaged equations of motion are presented and applied to long-term orbit prediction of an orbiting spacecraft around a slowly rotating planet, using the Venus Radar Mapper Mission as an example. The equations of motion used are valid for all eccentricities less than one. The disturbing potentials used include nonsphericity of the Venus gravity field and third-body effects due to the sun. Recursive relationships are used in the expansion and evaluation of these potentials and their respective partial derivatives. Special care is taken to optimize computational efficiency. The averaging method is compared with high precision Cowell's method using a desktop microcomputer and shows computational saving of about two orders of magnitude.

Transforming Mean and Osculating Elements Using Numerical Methods

NASA Technical Reports Server (NTRS)

Ely, Todd A.

2010-01-01

Mean element propagation of perturbed two body orbits has as its mathematical basis averaging theory of nonlinear dynamical systems. Averaged mean elements define the long-term evolution characteristics of an orbit. Using averaging theory, a near identity transformation can be found that transforms the mean elements back to the osculating elements that contain short period terms in addition to the secular and long period mean elements. The ability to perform the conversion is necessary so that orbit design conducted in mean elements can be converted back into osculating results. In the present work, this near identity transformation is found using the Fast Fourier Transform. An efficient method is found that is capable of recovering the osculating elements to first order

Nitrifying moving bed biofilm reactor (MBBR) biofilm and biomass response to long term exposure to 1 °C.

PubMed

Hoang, V; Delatolla, R; Abujamel, T; Mottawea, W; Gadbois, A; Laflamme, E; Stintzi, A

2014-02-01

This study aims to investigate moving bed biofilm reactor (MBBR) nitrification rates, nitrifying biofilm morphology, biomass viability as well as bacterial community shifts during long-term exposure to 1 °C. Long-term exposure to 1 °C is the key operational condition for potential ammonia removal upgrade units to numerous northern region treatment systems. The average laboratory MBBR ammonia removal rate after long-term exposure to 1 °C was measured to be 18 ± 5.1% as compared to the average removal rate at 20 °C. Biofilm morphology and specifically the thickness along with biomass viability at various depths in the biofilm were investigated using variable pressure electron scanning microscope (VPSEM) imaging and confocal laser scanning microscope (CLSM) imaging in combination with viability live/dead staining. The biofilm thickness along with the number of viable cells showed significant increases after long-term exposure to 1 °C. Hence, this study observed nitrifying bacteria with higher activities at warm temperatures and a slightly greater quantity of nitrifying bacteria with lower activities at cold temperatures in nitrifying MBBR biofilms. Using DNA sequencing analysis, Nitrosomonas and Nitrosospira (ammonia oxidizers) as well as Nitrospira (nitrite oxidizer) were identified and no population shift was observed between 20 °C and after long-term exposure to 1 °C. Copyright © 2013 Elsevier Ltd. All rights reserved.

Long-term ambient air pollution and lung function impairment in Chinese children from a high air pollution range area: The Seven Northeastern Cities (SNEC) study

NASA Astrophysics Data System (ADS)

Zeng, Xiao-Wen; Vivian, Elaina; Mohammed, Kahee A.; Jakhar, Shailja; Vaughn, Michael; Huang, Jin; Zelicoff, Alan; Xaverius, Pamela; Bai, Zhipeng; Lin, Shao; Hao, Yuan-Tao; Paul, Gunther; Morawska, Lidia; Wang, Si-Quan; Qian, Zhengmin; Dong, Guang-Hui

2016-08-01

Epidemiological studies have reported inconsistent and inconclusive associations between long-term exposure to ambient air pollution and lung function in children from Europe and America, where air pollution levels were typically low. The aim of the present study is to examine the relationship between air pollutants and lung function in children selected from heavily industrialized and polluted cities in northeastern China. During 2012, 6740 boys and girls aged 7-14 years were recruited in 24 districts of seven northeastern cities. Portable electronic spirometers were used to measure lung function. Four-year average concentrations of particulate matter with an aerodynamic diameter ≤10 μm (PM10), sulfur dioxide (SO2), nitrogen dioxide (NO2), and ozone (O3) were measured at monitoring stations in the 24 districts. Two-staged regression models were used in the data analysis, controlling for covariates. Overall, for all subjects, the increased odds of lung function impairment associated with exposure to air pollutants, ranged from 5% (adjusted odds ratio [aOR] = 1.05; 95% confidence interval [CI] = 1.01, 1.10) for FVC < 85% predicted per 46.3 μg/m3 for O3 to 81% (aOR = 1.81; 95%CI = 1.44, 2.28) for FEV1 < 85% predicted per 30.6 μg/m3 for PM10. The linear regression models consistently showed a negative relationship between all air pollutants and lung function measures across subjects. There were significant interaction terms indicating gender differences for lung function impairment and pulmonary function from exposure to some pollutants (P < 0.10). In conclusion, long term exposure to high concentrations of ambient air pollution is associated with decreased pulmonary function and lung function impairment, and females appear to be more susceptible than males.

Decadal and seasonal trends of nutrient concentration and export from highly managed coastal catchments.

PubMed

Wan, Yongshan; Wan, Lei; Li, Yuncong; Doering, Peter

2017-05-15

Understanding anthropogenic and hydro-climatic influences on nutrient concentrations and export from highly managed catchments often necessitates trend detection using long-term monitoring data. This study analyzed the temporal trend (1979-2014) of total nitrogen (TN) and total phosphorus (TP) concentrations and export from four adjacent coastal basins in south Florida where land and water resources are highly managed through an intricate canal network. The method of integrated seasonal-trend decomposition using LOESS (LOcally weighted regrESSion) was employed for trend detection. The results indicated that long-term trends in TN and TP concentrations (increasing/decreasing) varied with basins and nutrient species, reflecting the influence of basin specific land and water management practices. These long-term trends were intervened by short-term highs driven by high rainfall and discharges and lows associated with regional droughts. Seasonal variations in TP were more apparent than for TN. Nutrient export exhibited a chemostatic behavior for TN from all the basins, largely due to the biogenic nature of organic N associated with the ubiquity of organic materials in the managed canal network. Varying degrees of chemodynamic export was present for TP, reflecting complex biogeochemical responses to the legacy of long-term fertilization, low soil P holding capacity, and intensive stormwater management. The anthropogenic and hydro-climatic influences on nutrient concentration and export behavior had great implications in nutrient loading abatement strategies for aquatic ecosystem restoration of the downstream receiving waterbody. Published by Elsevier Ltd.

Correspondence between hair cortisol concentrations and 30-day integrated daily salivary and weekly urinary cortisol measures

PubMed Central

Short, Sarah J.; Stalder, Tobias; Marceau, Kristine P.; Entringer, Sonja; Moog, Nora K.; Shirtcliff, Elizabeth A.; Wadhwa, Pathik D.; Buss, Claudia

2016-01-01

Characterization of cortisol production, regulation and function is of considerable interest and relevance given its ubiquitous role in virtually all aspects of physiology, health and disease risk. The quantification of cortisol concentration in hair has been proposed as a promising approach for the retrospective assessment of integrated, long-term cortisol production. However, human research is still needed to directly test and validate current assumptions about which aspects of cortisol production and regulation are reflected in hair cortisol concentrations (HCC). Here, we report findings from a validation study in a sample of 17 healthy adults (mean ± SD age: 34 ± 8.6 yrs). To determine the extent to which HCC captures cumulative cortisol production, we examined the correspondence of HCC, obtained from the first 1cm scalp-near hair segment, assumed to retrospectively reflect 1-month integrated cortisol secretion, with 30-day average salivary cortisol area-under-the curve (AUC) based on 3 samples collected per day (on awakening, +30 min, at bedtime) and the average of 4 weekly 24-hr urinary free cortisol (UFC) assessments. To further address which aspects of cortisol production and regulation are best reflected in the HCC measure, we also examined components of the salivary measures that represent: 1) production in response to the challenge of awakening (using the cortisol awakening response [CAR]), and 2) chronobiological regulation of cortisol production (using diurnal slope). Finally, we evaluated the test-retest stability of each cortisol measure. Results indicate that HCC was most strongly associated with the prior 30-day integrated cortisol production measure (average salivary cortisol AUC) (r = 0.61, p = 0.01). There were no significant associations between HCC and the 30-day summary measures using CAR or diurnal slope. The relationship between 1-month integrated 24-hr UFC and HCC did not reach statistical significance (r = 0.30, p = 0.28). Lastly, of all cortisol measures, test-retest correlations of serial measures were highest for HCC (month-to-month: r = 0.84, p < 0.001), followed by 24-hr UFC (week-to-week: r’s between 0.59 and 0.68, ps < 0.05) and then integrated salivary cortisol concentrations (week-to-week: r’s between 0.38 and 0.61, p’s between 0.13 and 0.01). These findings support the contention that HCC provides a reliable estimate of long-term integrated free cortisol production that is aligned with integrated salivary cortisol production measured over a corresponding one-month period. PMID:27235635

Correspondence between hair cortisol concentrations and 30-day integrated daily salivary and weekly urinary cortisol measures.

PubMed

Short, Sarah J; Stalder, Tobias; Marceau, Kristine; Entringer, Sonja; Moog, Nora K; Shirtcliff, Elizabeth A; Wadhwa, Pathik D; Buss, Claudia

2016-09-01

Characterization of cortisol production, regulation and function is of considerable interest and relevance given its ubiquitous role in virtually all aspects of physiology, health and disease risk. The quantification of cortisol concentration in hair has been proposed as a promising approach for the retrospective assessment of integrated, long-term cortisol production. However, human research is still needed to directly test and validate current assumptions about which aspects of cortisol production and regulation are reflected in hair cortisol concentrations (HCC). Here, we report findings from a validation study in a sample of 17 healthy adults (mean±SD age: 34±8.6 yrs). To determine the extent to which HCC captures cumulative cortisol production, we examined the correspondence of HCC, obtained from the first 1cm scalp-near hair segment, assumed to retrospectively reflect 1-month integrated cortisol secretion, with 30-day average salivary cortisol area-under-the curve (AUC) based on 3 samples collected per day (on awakening, +30min, at bedtime) and the average of 4 weekly 24-h urinary free cortisol (UFC) assessments. To further address which aspects of cortisol production and regulation are best reflected in the HCC measure, we also examined components of the salivary measures that represent: (1) production in response to the challenge of awakening (using the cortisol awakening response [CAR]), and (2) chronobiological regulation of cortisol production (using diurnal slope). Finally, we evaluated the test-retest stability of each cortisol measure. Results indicate that HCC was most strongly associated with the prior 30-day integrated cortisol production measure (average salivary cortisol AUC) (r=0.61, p=0.01). There were no significant associations between HCC and the 30-day summary measures using CAR or diurnal slope. The relationship between 1-month integrated 24-h UFC and HCC did not reach statistical significance (r=0.30, p=0.28). Lastly, of all cortisol measures, test-retest correlations of serial measures were highest for HCC (month-to-month: r=0.84, p<0.001), followed by 24-h UFC (week-to-week: r's between 0.59 and 0.68, ps<0.05) and then integrated salivary cortisol concentrations (week-to-week: r's between 0.38 and 0.61, p's between 0.13 and 0.01). These findings support the contention that HCC provides a reliable estimate of long-term integrated free cortisol production that is aligned with integrated salivary cortisol production measured over a corresponding one-month period. Copyright © 2016 Elsevier Ltd. All rights reserved.

Sequential Neighborhood Effects: The Effect of Long-Term Exposure to Concentrated Disadvantage on Children's Reading and Math Test Scores.

PubMed

Hicks, Andrew L; Handcock, Mark S; Sastry, Narayan; Pebley, Anne R

2018-02-01

Prior research has suggested that children living in a disadvantaged neighborhood have lower achievement test scores, but these studies typically have not estimated causal effects that account for neighborhood choice. Recent studies used propensity score methods to account for the endogeneity of neighborhood exposures, comparing disadvantaged and nondisadvantaged neighborhoods. We develop an alternative propensity function approach in which cumulative neighborhood effects are modeled as a continuous treatment variable. This approach offers several advantages. We use our approach to examine the cumulative effects of neighborhood disadvantage on reading and math test scores in Los Angeles. Our substantive results indicate that recency of exposure to disadvantaged neighborhoods may be more important than average exposure for children's test scores. We conclude that studies of child development should consider both average cumulative neighborhood exposure and the timing of this exposure.

Sequential Neighborhood Effects: The Effect of Long-Term Exposure to Concentrated Disadvantage on Children's Reading and Math Test Scores

PubMed Central

Hicks, Andrew L.; Handcock, Mark S.; Sastry, Narayan

2018-01-01

Prior research has suggested that children living in a disadvantaged neighborhood have lower achievement test scores, but these studies typically have not estimated causal effects that account for neighborhood choice. Recent studies used propensity score methods to account for the endogeneity of neighborhood exposures, comparing disadvantaged and nondisadvantaged neighborhoods. We develop an alternative propensity function approach in which cumulative neighborhood effects are modeled as a continuous treatment variable. This approach offers several advantages. We use our approach to examine the cumulative effects of neighborhood disadvantage on reading and math test scores in Los Angeles. Our substantive results indicate that recency of exposure to disadvantaged neighborhoods may be more important than average exposure for children's test scores. We conclude that studies of child development should consider both average cumulative neighborhood exposure and the timing of this exposure. PMID:29192386

New York harbor water-quality survey, 1988-1990. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brosnan, T.M.

1991-08-27

Fifty two stations were monitored over twelve weeks of each of the summers of 1988 through 1990 to provide the 79th, 80th, and 81st Annual Summer Water Quality Surveys of New York Harbor. Coliform bacteria continue to exhibit significant long-term improvements throughout the harbor due to water pollution control plant construction and upgrades. Only 4% of stations were out of compliance with coliform standards in 1990, with exceedances confined to waterways heavily impacted by combined sewer overflows (CSO's). In 1990, average summer dissolved oxygen (DO) met state standards at 94% of surface, and 85% of bottom sites; however many sitesmore » contravened DO standards at least once. While average DO compliance in 1990 was significantly better than any time since at least 1986, 1988 and 1989 were noticeably worse, particularly in waterways prone to phytoplankton blooms and density stratification. Nutrient and chlorophyll a concentrations displayed spatial trends.« less

Aircraft pollution in the vicinity of airports

DOE Office of Scientific and Technical Information (OSTI.GOV)

Segal, H.M.

1981-01-01

A study carried out by the FAA and the Environmental Protection Agency that reassessed the impact of aircraft emissions on air quality around airports is discussed. Improvements in measuring techniques, for example, the use of vertical towers at different elevations, made it possible to compare emissions with the National Ambient Air Quality Standards (NAAQS). For CO, it was found that one-hour average concentrations never exceeded seven ppm, which is to be compared with the 35 ppm limiting level of the NAAQS. Emissions of NO/sub 2/ were only 10% of the long-term NAAQS standard. With regard to the short-term standard, however,more » the measurements were inconclusive because it is not yet known how much of the NO emitted by the engine is converted into NO/sub 2/ before reaching populated areas.« less

Tackling the mortality from long-term exposure to outdoor air pollution in megacities: Lessons from the Greater Cairo case study.

PubMed

Wheida, Ali; Nasser, Amira; El Nazer, Mostafa; Borbon, Agnes; Abo El Ata, Gehad A; Abdel Wahab, Magdy; Alfaro, Stephane C

2018-01-01

The poor outdoor air quality in megacities of the developing world and its impact on health is a matter of concern for both the local populations and the decision-makers. The objective of this work is to quantify the mortality attributable to long-term exposure to PM2.5, NO 2 , and O 3 in Greater Cairo (Egypt). We analyze the temporal and spatial variability of the three pollutants concentrations measured at 18 stations of the area. Then, we apply the method recommended by the WHO to estimate the excess mortality. In this assessment, three different shapes (log-linear, linear, and log-log) of the concentration-response functions (CRF) are used. With PM2.5 concentrations varying from 50 to more than 100µg/m 3 in the different sectors of the megacity, the spatial variability of this pollutant is found to be one important cause of uncertainty on the excess mortality associated with it. Also important is the choice of the CRF. With the average (75µg/m 3 ) PM2.5 concentration and the most favorable log-log shape of the CRF, 11% (CI, 9-14%) of the non-accidental mortality in the population older than 30 years can still be attributed to PM2.5, which corresponds to 12520 (CI, 10240-15930) yearly premature deaths. Should the Egyptian legal 70µg/m 3 PM10 limit (corresponding to approximately 37.5µg/m 3 for PM2.5) be met, this number would be reduced to 7970, meaning that 4550 premature deaths could be avoided each year. Except around some industrial or traffic hot spots, NO 2 concentration is found to be below the 40µg/m 3 air quality guideline of the WHO. However, the average concentration (34µg/m 3 ) of this gas exceeds the stricter 10µg/m 3 recommendation of the HRAPIE project and it is thus estimated that from 7850 to 10470 yearly deaths can be attributed to NO 2 . Finally, with the ozone concentration measured at one station only, it is found that, depending on the choice of the CRF, between 2.4% and 8.8% of the mortality due to respiratory diseases can be attributed to this gas. In Greater Cairo, PM2.5 and NO 2 constitute major health risks. The best estimate is that in the population older than 30 years, 11% and 8% of the non-accidental mortality can be attributed to these two pollutants, respectively. Copyright © 2017 Elsevier Inc. All rights reserved.

Short-term variability and long-term change in the composition of the littoral zone fish community in Spirit Lake, Iowa

USGS Publications Warehouse

Pierce, C.L.; Sexton, M.D.; Pelham, M.E.; Larscheid, J.G.

2001-01-01

We assessed short-term variability and long-term change in the composition of the littoral fish community in Spirit Lake, Iowa. Fish were sampled in several locations at night with large beach seines during spring, summer and fall of 1995-1998. Long-term changes were inferred from comparison with a similar study conducted over 70 y earlier in Spirit Lake. We found 26 species in the littoral zone. The number of species per sample ranged from 4 to 18, averaging 11.8. The average number of species per sample was higher at stations with greater vegetation density. A distinct seasonal pattern was evident in the number of species collected per sample in most years, increasing steadily from spring to fall. Patterns of variability within our 1995-1998 study period suggest that: (1) numerous samples are necessary to adequately characterize a littoral fish community, (2) sampling should be done when vegetation and young-of-year densities are highest and (3) sampling during a single year is inadequate to reveal the full community. The number of native species has declined by approximately 25% over the last 70 y. A coincident decline in littoral vegetation and associated habitat changes during the same period are likely causes of the long-term community change.

Long-Term Exposure to Ozone and Life Expectancy in the United States, 2002 to 2008

PubMed Central

Li, Chaoyang; Balluz, Lina S.; Vaidyanathan, Ambarish; Wen, Xiao-Jun; Hao, Yongping; Qualters, Judith R.

2016-01-01

Abstract Long-term exposure to ground-level ozone is associated with increased risk of morbidity and mortality. The association remains uncertain between long-term exposure to ozone and life expectancy. We assessed the associations between seasonal mean daily 8-hour maximum (8-hr max) ozone concentrations measured during the ozone monitoring seasons and life expectancy at birth in 3109 counties of the conterminous U.S. during 2002 to 2008. We used latent class growth analysis to identify latent classes of counties that had distinct mean levels and rates of change in ozone concentrations over the 7-year period and used linear regression analysis to determine differences in life expectancy by ozone levels. We identified 3 classes of counties with distinct seasonal mean daily 8-hr max ozone concentrations and rates of change. When compared with the counties with the lowest ozone concentrations, the counties with the highest ozone concentrations had 1.7- and 1.4-year lower mean life expectancy in males and females (both P < 0.0001), respectively. The associations remained statistically significant after controlling for potential confounding effects of seasonal mean PM2.5 concentrations and other selected environmental, demographic, socio-economic, and health-related factors (both P < 0.0001). A 5 ppb higher ozone concentration was associated with 0.25 year lower life expectancy in males (95% CI: −0.30 to −0.19) and 0.21 year in females (95% CI: −0.25 to −0.17). We identified 3 classes of counties with distinct mean levels and rates of change in ozone concentrations. Our findings suggest that long-term exposure to a higher ozone concentration may be associated with a lower life expectancy. PMID:26886595

Timing of solid food introduction is associated with urinary F2-isoprostane concentrations in childhood.

PubMed

Frederiksen, Brittni N; Seifert, Jennifer; Kroehl, Miranda; Lamb, Molly M; Milne, Ginger L; Rewers, Marian; Norris, Jill M

2015-10-01

Timing of solid food introduction in infancy has been associated with several chronic diseases. To explore potential mechanisms, we investigated the relationship between timing of solid food introduction and F2-isoprostanes-a marker of oxidative stress. Urinary F2-isoprostanes were assessed in 336 healthy children aged less than 11.5 y with 1,266 clinic visits (mean = 3.8 visits per child) in the Diabetes Autoimmunity Study in the Young. We analyzed the association between F2-isoprostane concentrations and infant diet exposures using linear mixed models adjusted for age, age(2), HLA-DR3/4,DQB1*0302 genotype, first-degree relative with type 1 diabetes, maternal age, maternal education, sex, and exposure to in utero cigarette smoke. Later solid food introduction was associated with lower F2-isoprostane concentrations in childhood (on average, 0.10 ng/mg per month of age at introduction; estimate: -0.10 (95% confidence interval (CI): -0.18, -0.02) P value = 0.02). Moreover, childhood F2-isoprostane concentrations were, on average, 0.24 ng/mg lower in individuals breastfed at solid food introduction (estimate: -0.24 (95% CI: -0.47, -0.01) P value = 0.04) compared with those who were not. Associations remained significant after limiting analyses to F2-isoprostanes after 2 y of age. Our results suggest a long-term protective effect of later solid food introduction and breastfeeding at solid food introduction against increased F2-isoprostane concentrations throughout childhood.

Long-term Use of Opioids for Complex Chronic Pain

PubMed Central

Von Korff, Michael R.

2014-01-01

Increased opioid prescribing for back pain and other chronic musculoskeletal pain conditions has been accompanied by dramatic increases in prescription opioid addiction and fatal overdose. Opioid-related risks appear to increase with dose. While short-term randomized trials of opioids for chronic pain have found modest analgesic benefits (a one-third reduction in pain intensity on average), the long-term safety and effectiveness of opioids for chronic musculoskeletal pain is unknown. Given the lack of large, long-term randomized trials, recent epidemiologic data suggests the need for caution when considering long-term use of opioids to manage chronic musculoskeletal pain, particularly at higher dosage levels. Principles for achieving more selective and cautious use of opioids for chronic musculoskeletal pain are proposed. PMID:24315147

Long-term outcomes of vertebral column resection for kyphosis in patients with cured spinal tuberculosis: average 8-year follow-up.

PubMed

Liu, Congcong; Lin, Li; Wang, Weixing; Lv, Guohua; Deng, Youwen

2016-05-01

OBJECTIVE The authors conducted a study to evaluate the long-term clinical and radiographic outcomes of vertebral column resection (VCR) for kyphosis in patients with cured spinal tuberculosis. METHODS This was a retrospective study. Between 2003 and 2009, 28 consecutive patients with cured spinal tuberculosis underwent VCR for kyphosis in which the target vertebra was removed completely. Autologous iliac crest bone graft or titanium mesh packed with autograft was placed into the osteotomy gap to reconstruct the spine for anterior column stability. Posterior pedicle screw fixation and fusion were typically performed. Radiographic parameters, including kyphosis angle and sagittal balance, were measured, and visual analog scale score, America Spinal Injury Association grade, Scoliosis Research Society outcome instrument (SRS-22) score, Oswestry Disability Index, patient satisfaction index, and long-term complications were evaluated. RESULTS This study included 12 males and 16 females, with an average age of 20.9 years at the time of surgery. The average follow-up was 96.9 months. No deaths occurred in this study. At the final follow-up, the kyphosis angle improved from the preoperative average of 70.7° to the final follow-up average of 30.2°, and the average kyphosis correction loss was 8.5°. The sagittal balance averaged 15.4 mm before surgery, 2.8 mm after surgery, and 5.4 mm at the final followup. Thirteen patients showed improvement of more than 1 America Spinal Injury Association grade. The visual analog scale, Oswestry Disability Index, and SRS-22 scores improved significantly, and the overall satisfaction rate was 92.9%. Adjacent-segment degeneration occurred in 3 patients. No severe instrumentation-related complications were observed. CONCLUSIONS The long-term safety and efficacy of the VCR technique for treating spinal tuberculosis-related kyphosis were favorable, and no severe late-stage complications appeared. Lumbar tubercular kyphosis showed a tendency for sagittal decompensation within the first 3 postoperative years. Cases of adjacent-segment degenerations were relatively few and mild without clinical symptoms.

Short-term and long-term effects of guar on postprandial plasma glucose, insulin and glucagon-like peptide 1 concentration in healthy rats.

PubMed

Prieto, P G; Cancelas, J; Villanueva-Peñacarrillo, M L; Malaisse, W J; Valverde, I

2006-06-01

Ingestion of guar gum decreases postprandial glycemia and insulinemia and improves sensitivity to insulin in diabetic patients and several animal models of diabetes. The aim of the present study was to compare the short-term and long-term effects of guar on plasma insulin and glucagon-like peptide 1 concentration in healthy rats. In the short-term experiments, the concomitant intragastric administration of glucose and guar reduced the early increment in plasma glucose, insulin and glucagon-like peptide 1 concentration otherwise induced by glucose alone. Comparable findings were made after twelve days of meal training exposing the rats to either a control or guar-enriched diet for fifteen minutes. Mean plasma glucose concentrations were lower while mean insulin concentrations were higher in the guar group than in the controls according to intragastric glucose tolerance tests conducted in overnight fasted rats maintained for 19 to 36 days on either the control or guar-enriched diet. The intestinal content of glucagon-like peptide 1 at the end of the experiments was also lower in the guar group. Changes in body weight over 62 days of observation were comparable in the control and guar rats. Thus, long-term intake of guar improves glucose tolerance and insulin response to glucose absorption, without improving insulin sensitivity, in healthy rats.

Long-term variability in sugarcane bagasse feedstock compositional methods: Sources and magnitude of analytical variability

DOE PAGES

Templeton, David W.; Sluiter, Justin B.; Sluiter, Amie; ...

2016-10-18

In an effort to find economical, carbon-neutral transportation fuels, biomass feedstock compositional analysis methods are used to monitor, compare, and improve biofuel conversion processes. These methods are empirical, and the analytical variability seen in the feedstock compositional data propagates into variability in the conversion yields, component balances, mass balances, and ultimately the minimum ethanol selling price (MESP). We report the average composition and standard deviations of 119 individually extracted National Institute of Standards and Technology (NIST) bagasse [Reference Material (RM) 8491] run by seven analysts over 7 years. Two additional datasets, using bulk-extracted bagasse (containing 58 and 291 replicates each),more » were examined to separate out the effects of batch, analyst, sugar recovery standard calculation method, and extractions from the total analytical variability seen in the individually extracted dataset. We believe this is the world's largest NIST bagasse compositional analysis dataset and it provides unique insight into the long-term analytical variability. Understanding the long-term variability of the feedstock analysis will help determine the minimum difference that can be detected in yield, mass balance, and efficiency calculations. The long-term data show consistent bagasse component values through time and by different analysts. This suggests that the standard compositional analysis methods were performed consistently and that the bagasse RM itself remained unchanged during this time period. The long-term variability seen here is generally higher than short-term variabilities. It is worth noting that the effect of short-term or long-term feedstock compositional variability on MESP is small, about $0.03 per gallon. The long-term analysis variabilities reported here are plausible minimum values for these methods, though not necessarily average or expected variabilities. We must emphasize the importance of training and good analytical procedures needed to generate this data. As a result, when combined with a robust QA/QC oversight protocol, these empirical methods can be relied upon to generate high-quality data over a long period of time.« less

Long-term variability in sugarcane bagasse feedstock compositional methods: Sources and magnitude of analytical variability

DOE Office of Scientific and Technical Information (OSTI.GOV)

Templeton, David W.; Sluiter, Justin B.; Sluiter, Amie

In an effort to find economical, carbon-neutral transportation fuels, biomass feedstock compositional analysis methods are used to monitor, compare, and improve biofuel conversion processes. These methods are empirical, and the analytical variability seen in the feedstock compositional data propagates into variability in the conversion yields, component balances, mass balances, and ultimately the minimum ethanol selling price (MESP). We report the average composition and standard deviations of 119 individually extracted National Institute of Standards and Technology (NIST) bagasse [Reference Material (RM) 8491] run by seven analysts over 7 years. Two additional datasets, using bulk-extracted bagasse (containing 58 and 291 replicates each),more » were examined to separate out the effects of batch, analyst, sugar recovery standard calculation method, and extractions from the total analytical variability seen in the individually extracted dataset. We believe this is the world's largest NIST bagasse compositional analysis dataset and it provides unique insight into the long-term analytical variability. Understanding the long-term variability of the feedstock analysis will help determine the minimum difference that can be detected in yield, mass balance, and efficiency calculations. The long-term data show consistent bagasse component values through time and by different analysts. This suggests that the standard compositional analysis methods were performed consistently and that the bagasse RM itself remained unchanged during this time period. The long-term variability seen here is generally higher than short-term variabilities. It is worth noting that the effect of short-term or long-term feedstock compositional variability on MESP is small, about $0.03 per gallon. The long-term analysis variabilities reported here are plausible minimum values for these methods, though not necessarily average or expected variabilities. We must emphasize the importance of training and good analytical procedures needed to generate this data. As a result, when combined with a robust QA/QC oversight protocol, these empirical methods can be relied upon to generate high-quality data over a long period of time.« less

76 FR 60935 - Notice of Application from ExxonMobil Corporation, Highland Uranium Mine and Millsite, To Amend...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-30

... and Extend the NRC Long-Term Surveillance Boundary With Respect to Materials License SUA-1139 AGENCY... concentration limits and to extend the NRC Long-Term Surveillance Boundary at its Highland Uranium Mine and Mill... wells and at the proposed POC well. The amendment also proposes to expand the Long-Term Surveillance...

Variability of Changjiang Diluted Water revealed by a 45-year long-term ocean hindcast and Self-Organizing Maps analysis

NASA Astrophysics Data System (ADS)

Zeng, Xiangming; He, Ruoying; Zong, Haibo

2017-08-01

Based on long-term realistic ocean circulation hindcast for in the Bohai, Yellow, and East China Seas, 45 years (1961-2005) of sea surface salinity data were analyzed using Self-Organizing Maps (SOM) to have a better understanding of the Changjiang Diluted Water (CDW) variation. Three spatial patterns were revealed by the SOM: normal, transition, and extension. The normal pattern mainly occurs from December to May while the CDW hugs China's east coast closely and flows southward. The extension pattern is dominant from June to October when the CDW extends northwestward toward Jeju Island in an omega shape. The transition pattern prevails for the rest of the year. Pattern-averaged temperature, circulation, and chlorophyll-a concentration show significant differences. CDW area and its eastern most extension were explored as a function of the Changjiang runoff and regional upwelling index. We found that Changjiang runoff and upwelling index can be reasonable predictors for the overall CDW area, while ambient circulation determines the distribution and structure of the CDW, and thus the CDW eastern most extension.

Low pH Springs - A Natural Laboratory for Ocean Acidification

NASA Astrophysics Data System (ADS)

Derse, E.; Rebolledo-Vieyra, M.; Potts, D. C.; Paytan, A.

2009-12-01

Recent increases in atmospheric carbon dioxide of 40% above pre-industrial levels has resulted in rising aqueous CO2 concentrations that lower the pH of the oceans. Currently, the surface ocean has an average pH between 8.1 and 8.2: it is estimated that over the next 100 years this value will decrease by ~0.4 pH units. Previous studies have highlighted the negative impacts that changes in pH (and the resulting CaCO3 saturation state) have on marine organisms; however, to date, very little is known about the long-term impacts of ocean acidification on ecosystems as a whole. The Yucatán Peninsula of Quintana Roo, Mexico, represents an ecosystem where naturally low pH groundwater (7.25-8.07) has been discharging offshore at highly localized points (called ojos) since the last deglaciation. We present preliminary chemical and biological data on a selection of ojos from lagoon sites in Puerto Morelos, Mexico. We address the potential long-term implications of low pH waters on marine ecosystems.

Long-term study on workers occupationally exposed to ethylbenzene.

PubMed

Bardodĕj, Z; Círek, A

1988-01-01

Ethylbenzene is synthesized from benzene; subject to catalytic dehydrogenation it yields styrene, a raw material for the production of synthetic rubber and plastics. Long-term biomonitoring of occupational ethylbenzene exposures, carried out in the past 20 years in some 200 ethylbenzene-production workers, revealed this substance to pose little hazard to human health. As it turned out, mandelic acid concentrations in these workers' urine never exceeded 3.25 mmol.l-1 and none of the exposed showed damage to hematopoiesis and/or liver tissue. Over the last 10 years no case of malignancy has been recorded in this industrial facility belonging to a larger chemical complex where the overall incidence of cancer is about 3 times the national average. Today's low-level ethylbenzene exposures would make it fully justifiable if the present-day MAC limits, both whole-shift (200 mg.m-3) and peak (1,000 mg.m-3), were to be halved, i.e. to be lowered to 100 mg.m3 and 500 mg.m3 respectively. These newly recommended limit values are no more exceeded nowadays.

Personality as a predictor of weight loss maintenance after surgery for morbid obesity.

PubMed

Larsen, Junilla K; Geenen, Rinie; Maas, Cora; de Wit, Pieter; van Antwerpen, Tiny; Brand, Nico; van Ramshorst, Bert

2004-11-01

Personality characteristics are assumed to underlie health behaviors and, thus, a variety of health outcomes. Our aim was to examine prospectively whether personality traits predict short- and long-term weight loss after laparoscopic adjustable gastric banding. Of patients undergoing laparoscopic adjustable gastric banding, 168 (143 women, 25 men, 18 to 58 years old, mean 37 years, preoperative BMI 45.9 +/- 5.6 kg/m(2)) completed the Dutch Personality Questionnaire on average 1.5 years before the operation. The relationship between preoperative personality and short- and long-term postoperative weight loss was determined using multilevel regression analysis. The average weight loss of patients progressively increased to 10 BMI points until 18 months after surgery and stabilized thereafter. A lower baseline BMI, being a man, and a higher educational level were associated with a lower weight loss. None of the personality variables was associated with weight outcome at short-term follow-up. Six of seven personality variables did not predict long-term weight outcome. Egoism was associated with less weight loss in the long-term postoperative period. The effect sizes of the significant predictions were small. None of the personality variables predicted short-term weight outcome, and only one variable showed a small and unexpected association with long-term weight outcome that needs confirmation. This suggests that personality assessment as intake psychological screening is of little use for the prediction of a poor or successful weight outcome after bariatric surgery.

Modeling storms improves estimates of long-term shoreline change

NASA Astrophysics Data System (ADS)

Frazer, L. Neil; Anderson, Tiffany R.; Fletcher, Charles H.

2009-10-01

Large storms make it difficult to extract the long-term trend of erosion or accretion from shoreline position data. Here we make storms part of the shoreline change model by means of a storm function. The data determine storm amplitudes and the rate at which the shoreline recovers from storms. Historical shoreline data are temporally sparse, and inclusion of all storms in one model over-fits the data, but a probability-weighted average model shows effects from all storms, illustrating how model averaging incorporates information from good models that might otherwise have been discarded as un-parsimonious. Data from Cotton Patch Hill, DE, yield a long-term shoreline loss rate of 0.49 ± 0.01 m/yr, about 16% less than published estimates. A minimum loss rate of 0.34 ± 0.01 m/yr is given by a model containing the 1929, 1962 and 1992 storms.

Geothermal production and reduced seismicity: Correlation and proposed mechanism

DOE PAGES

Cardiff, Michael; Lim, David D.; Patterson, Jeremy R.; ...

2018-01-15

At Brady Hot Springs, a geothermal field in Nevada, heated fluids have been extracted, cooled, and re-injected to produce electrical power since 1992. Analysis of daily pumping records and catalogs of microseismicity between 2010 and 2015 indicates a statistically significant correlation between days when the daily volume of production was at or above its long-term average rate and days when no seismic event was detected. Conversely, shutdowns in pumping for plant maintenance correlate with increased microseismicity. Our hypothesis is that the effective stress in the subsurface has adapted to the long-term normal operations (deep extraction) at the site. Under thismore » hypothesis, extraction of fluids inhibits fault slip by increasing the effective stress on faults; in contrast, brief pumping cessations represent times when effective stress is decreased below its long-term average, increasing the likelihood of microseismicity.« less

Geothermal production and reduced seismicity: Correlation and proposed mechanism

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cardiff, Michael; Lim, David D.; Patterson, Jeremy R.

At Brady Hot Springs, a geothermal field in Nevada, heated fluids have been extracted, cooled, and re-injected to produce electrical power since 1992. Analysis of daily pumping records and catalogs of microseismicity between 2010 and 2015 indicates a statistically significant correlation between days when the daily volume of production was at or above its long-term average rate and days when no seismic event was detected. Conversely, shutdowns in pumping for plant maintenance correlate with increased microseismicity. Our hypothesis is that the effective stress in the subsurface has adapted to the long-term normal operations (deep extraction) at the site. Under thismore » hypothesis, extraction of fluids inhibits fault slip by increasing the effective stress on faults; in contrast, brief pumping cessations represent times when effective stress is decreased below its long-term average, increasing the likelihood of microseismicity.« less

Antecedent flow conditions and nitrate concentrations in the Mississippi River basin

USGS Publications Warehouse

Murphy, Jennifer C.; Hirsch, Robert M.; Sprague, Lori A.

2014-01-01

The relationship between antecedent flow conditions and nitrate concentrations was explored at eight sites in the 2.9 million square kilometers (km2) Mississippi River basin, USA. Antecedent flow conditions were quantified as the ratio between the mean daily flow of the previous year and the mean daily flow from the period of record (Qratio), and the Qratio was statistically related to nitrate anomalies (the unexplained variability in nitrate concentration after filtering out season, long-term trend, and contemporaneous flow effects) at each site. Nitrate anomaly and Qratio were negatively related at three of the four major tributary sites and upstream in the Mississippi River, indicating that when mean daily streamflow during the previous year was lower than average, nitrate concentrations were higher than expected. The strength of these relationships increased when data were subdivided by contemporaneous flow conditions. Five of the eight sites had significant negative relationships (p ≤ 0.05) at high or moderately high contemporaneous flows, suggesting nitrate that accumulates in these basins during a drought is flushed during subsequent high flows. At half of the sites, when mean daily flow during the previous year was 50 percent lower than average, nitrate concentration can be from 9 to 27 percent higher than nitrate concentrations that follow a year with average mean daily flow. Conversely, nitrate concentration can be from 8 to 21 percent lower than expected when flow during the previous year was 50 percent higher than average. Previously documented for small, relatively homogenous basins, our results suggest that relationships between antecedent flows and nitrate concentrations are also observable at a regional scale. Relationships were not observed (using all contemporaneous flow data together) for basins larger than 1 million km2, suggesting that above this limit the overall size and diversity within these basins may necessitate the use of more complicated statistical approaches or that there may be no discernible basin-wide relationship with antecedent flow. The relationships between nitrate concentration and Qratio identified in this study serve as the basis for future studies that can better define specific hydrologic processes occurring during and after a drought (or high flow period) which influence nitrate concentration, such as the duration or magnitude of low flows, and the timing of low and high flows.

Neither short-term nor long-term administration of oral choline alters metabolite concentrations in human brain.

PubMed

Dechent, P; Pouwels, P J; Frahm, J

1999-08-01

This study reexamined conflicting proton magnetic resonance spectroscopy (MRS) reports of increased or unaffected choline-containing compounds (Cho) in human brain in response to a single dose of 50 mg/kg choline bitartrate. The present work was based on a well-established strategy for quantitative proton MRS (2.0 T, STEAM localization sequence, TR/TE/TM = 6000/20/10 ms, LCModel automated spectral evaluation) that allows the determination of cerebral metabolite concentrations rather than T1-weighted resonance intensity ratios. Moreover, the investigations were extended to a possible long-term effect of oral choline by monitoring the continuous ingestion of 2 x 16 g of lecithin per day for 4 weeks. Six young healthy volunteers participated in each study and metabolite concentrations were determined in standardized locations in gray matter, white matter, cerebellum, and thalamus. Neither for short-term nor for long-term administration of choline do the data reveal statistically significant deviations from the basal concentrations of Cho, total N-acetyl-containing compounds (neuronal markers), total creatine, and myo-inositol (glial marker) in any of the investigated brain regions. Previous reports of increased Cho are not confirmed.

Impacts of Early Childhood Education on Medium- and Long-Term Educational Outcomes

ERIC Educational Resources Information Center

McCoy, Dana Charles; Yoshikawa, Hirokazu; Ziol-Guest, Kathleen M.; Duncan, Greg J.; Schindler, Holly S.; Magnuson, Katherine; Yang, Rui; Koepp, Andrew; Shonkoff, Jack P.

2017-01-01

Despite calls to expand early childhood education (ECE) in the United States, questions remain regarding its medium- and long-term impacts on educational outcomes. We use meta-analysis of 22 high-quality experimental and quasi-experimental studies conducted between 1960 and 2016 to find that on average, participation in ECE leads to statistically…

Civil Conflict and Human Capital Accumulation: The Long-Term Effects of Political Violence in Peru

ERIC Educational Resources Information Center

Leon, Gianmarco

2012-01-01

This paper provides empirical evidence of the persistent effect of exposure to political violence on human capital accumulation. I exploit the variation in conflict location and birth cohorts to identify the long- and short-term effects of the civil war on educational attainment. Conditional on being exposed to violence, the average person…

Cerebrospinal fluid kynurenine and kynurenic acid concentrations are associated with coma duration and long-term neurocognitive impairment in Ugandan children with cerebral malaria.

PubMed

Holmberg, Dag; Franzén-Röhl, Elisabeth; Idro, Richard; Opoka, Robert O; Bangirana, Paul; Sellgren, Carl M; Wickström, Ronny; Färnert, Anna; Schwieler, Lilly; Engberg, Göran; John, Chandy C

2017-07-28

One-fourth of children with cerebral malaria (CM) retain cognitive sequelae up to 2 years after acute disease. The kynurenine pathway of the brain, forming neuroactive metabolites, e.g. the NMDA-receptor antagonist kynurenic acid (KYNA), has been implicated in long-term cognitive dysfunction in other CNS infections. In the present study, the association between the kynurenine pathway and neurologic/cognitive complications in children with CM was investigated. Cerebrospinal fluid (CSF) concentrations of KYNA and its precursor kynurenine in 69 Ugandan children admitted for CM to Mulago Hospital, Kampala, Uganda, between 2008 and 2013 were assessed. CSF kynurenine and KYNA were compared to CSF cytokine levels, acute and long-term neurologic complications, and long-term cognitive impairments. CSF kynurenine and KYNA from eight Swedish children without neurological or infectious disease admitted to Astrid Lindgren's Children's Hospital were quantified and used for comparison. Children with CM had significantly higher CSF concentration of kynurenine and KYNA than Swedish children (P < 0.0001 for both), and CSF kynurenine and KYNA were positively correlated. In children with CM, CSF kynurenine and KYNA concentrations were associated with coma duration in children of all ages (P = 0.003 and 0.04, respectively), and CSF kynurenine concentrations were associated with worse overall cognition (P = 0.056) and attention (P = 0.003) at 12-month follow-up in children ≥5 years old. CSF KYNA and kynurenine are elevated in children with CM, indicating an inhibition of glutamatergic and cholinergic signaling. This inhibition may lead acutely to prolonged coma and long-term to impairment of attention and cognition.

Developing the remote sensing-based early warning system for monitoring TSS concentrations in Lake Mead.

PubMed

Imen, Sanaz; Chang, Ni-Bin; Yang, Y Jeffrey

2015-09-01

Adjustment of the water treatment process to changes in water quality is a focus area for engineers and managers of water treatment plants. The desired and preferred capability depends on timely and quantitative knowledge of water quality monitoring in terms of total suspended solids (TSS) concentrations. This paper presents the development of a suite of nowcasting and forecasting methods by using high-resolution remote-sensing-based monitoring techniques on a daily basis. First, the integrated data fusion and mining (IDFM) technique was applied to develop a near real-time monitoring system for daily nowcasting of the TSS concentrations. Then a nonlinear autoregressive neural network with external input (NARXNET) model was selected and applied for forecasting analysis of the changes in TSS concentrations over time on a rolling basis onward using the IDFM technique. The implementation of such an integrated forecasting and nowcasting approach was assessed by a case study at Lake Mead hosting the water intake for Las Vegas, Nevada, in the water-stressed western U.S. Long-term monthly averaged results showed no simultaneous impact from forest fire events on accelerating the rise of TSS concentration. However, the results showed a probable impact of a decade of drought on increasing TSS concentration in the Colorado River Arm and Overton Arm. Results of the forecasting model highlight the reservoir water level as a significant parameter in predicting TSS in Lake Mead. In addition, the R-squared value of 0.98 and the root mean square error of 0.5 between the observed and predicted TSS values demonstrates the reliability and application potential of this remote sensing-based early warning system in terms of TSS projections at a drinking water intake. Copyright © 2015 Elsevier Ltd. All rights reserved.

High-resolution satellite remote sensing of provincial PM2.5 trends in China from 2001 to 2015

NASA Astrophysics Data System (ADS)

Lin, C. Q.; Liu, G.; Lau, A. K. H.; Li, Y.; Li, C. C.; Fung, J. C. H.; Lao, X. Q.

2018-05-01

Given the vast territory of China, the long-term PM2.5 trends may substantially differ among the provinces. In this study, we aim to assess the provincial PM2.5 trends in China during the past few Five-Year Plan (FYP) periods. The lack of long-term PM2.5 measurements, however, makes such assessment difficult. Satellite remote sensing of PM2.5 concentration is an important step toward filling this data gap. In this study, a PM2.5 data set was built over China at a resolution of 1 km from 2001 to 2015 using satellite remote sensing. Analyses show that the national average of PM2.5 concentration increased by 0.04 μg·m-3·yr-1 during the 10th FYP period (2001-2005) and started to decline by -0.65 μg·m-3·yr-1 and -2.33 μg·m-3·yr-1 during the 11th (2006-2010) and the 12th (2011-2015) FYP period, respectively. In addition, substantial differences in the PM2.5 trends were observed among the provinces. Provinces in the Beijing-Tianjin-Hebei (BTH) region had the largest reduction of PM2.5 concentrations during the 10th and 12th FYP period. The greatest reduction rate of PM2.5 concentration during the 10th and 12th FYP period was observed in Beijing (-3.68 μg·m-3·yr-1) and Tianjin (-6.62 μg·m-3·yr-1), respectively. In contrast, PM2.5 concentrations remained steady for provinces in eastern and southeastern China (e.g., Shanghai) during the 12th FYP period. In overall, great efforts are still required to effectively reduce the PM2.5 concentrations in future.

Reducing soil phosphorus fertility brings potential long-term environmental gains: A UK analysis

NASA Astrophysics Data System (ADS)

Withers, Paul J. A.; Hodgkinson, Robin A.; Rollett, Alison; Dyer, Chris; Dils, Rachael; Collins, Adrian L.; Bilsborrow, Paul E.; Bailey, Geoff; Sylvester-Bradley, Roger

2017-05-01

Soil phosphorus (P) fertility arising from historic P inputs is a major driver of P mobilisation in agricultural runoff and increases the risk of aquatic eutrophication. To determine the environmental benefit of lowering soil P fertility, a meta-analysis of the relationship between soil test P (measured as Olsen-P) and P concentrations in agricultural drainflow and surface runoff in mostly UK soils was undertaken in relation to current eutrophication control targets (30-35 µg P L-1). At agronomic-optimum Olsen P (16-25 mg kg-1), concentrations of soluble reactive P (SRP), total dissolved P (TDP), total P (TP) and sediment-P (SS-P) in runoff were predicted by linear regression analysis to vary between 24 and 183 µg L-1, 38 and 315 µg L-1, 0.2 and 9.6 mg L-1, and 0.31 and 3.2 g kg-1, respectively. Concentrations of SRP and TDP in runoff were much more sensitive to changes in Olsen-P than were TP and SS-P concentrations, which confirms that separate strategies are required for mitigating the mobilisation of dissolved and particulate P forms. As the main driver of eutrophication, SRP concentrations in runoff were reduced on average by 60 µg L-1 (71%) by lowering soil Olsen-P from optimum (25 mg kg-1) to 10 mg kg-1. At Olsen-P concentrations below 12 mg kg-1, dissolved hydrolysable P (largely organic) became the dominant form of soluble P transported. We concluded that maintaining agronomic-optimum Olsen-P could still pose a eutrophication risk, and that a greater research focus on reducing critical soil test P through innovative agro-engineering of soils, crops and fertilisers would give long-term benefits in reducing the endemic eutrophication risk arising from legacy soil P. Soil P testing should become compulsory in priority catchments suffering, or sensitive to, eutrophication to ensure soil P reserves are fully accounted for as part of good fertiliser and manure management.

Identification and characterisation of local aerosol sources using high temporal resolution measurements.

PubMed

Contini, D; Donateo, A; Cesari, D; Belosi, F; Francioso, S

2010-09-01

Aerosol and gaseous pollution measurements were carried out at an urban background site in the south of Italy located near an industrial complex. Collection of 24 h samples of PM10 and PM2.5 and successive chemical quantification of metals were performed. Data were compared with measurements taken at a suburban background site, located at 25 km distance. The comparison showed the presence of an industrial contribution with a well defined chemical emission profile, similar, in terms of metals content, to urban emissions. As this made difficult the quantitative characterisation of the contribution of the two sources to atmospheric PM, a statistical method based on the treatment of data arising from high temporal resolution measurements was developed. Data were taken with a micrometeorological station based on an integrating nephelometer (Mie pDR-1200) for optical detection of PM2.5 concentration, with successive evaluation of vertical turbulent fluxes using the eddy-correlation method. Results show that the contribution from the two sources (urban emissions and industrial releases) have a very different behaviour, with the industrial contribution being present at high wind velocity with short concentration peaks (average duration 4 min) associated to strong positive and negative vertical fluxes. The estimated contribution to PM2.5 is 2.3% over long-term averages. The urban emissions are mainly present at low wind velocity, with longer concentration peaks in the morning and late evening hours, generally associated to small positive vertical fluxes. The characterisation of the contribution was performed using deposition velocity V(d) that is on average -3.5 mm s(-1) and has a diurnal pattern, with negligible values during the night and a minimum value of around -9 mm s(-1) late in the afternoon. Results show a correlation between V(d), friction velocity and wind velocity that could be the basis for a parameterisation of V(d) to be used in dispersion codes.

Covariation of climate and long-term erosion rates acrossa steep rainfall gradient on the Hawaiian island of Kaua'i

USGS Publications Warehouse

Ken Ferrier,; J. Taylor Perron,; Sujoy Mukhopadhyay,; Matt Rosener,; Stock, Jonathan; Slosberg, Michelle; Kimberly L. Huppert,

2013-01-01

Erosion of volcanic ocean islands creates dramatic landscapes, modulates Earth’s carbon cycle, and delivers sediment to coasts and reefs. Because many volcanic islands have large climate gradients and minimal variations in lithology and tectonic history, they are excellent natural laboratories for studying climatic effects on the evolution of topography. Despite concerns that modern sediment fluxes to island coasts may exceed long-term fluxes, little is known about how erosion rates and processes vary across island interiors, how erosion rates are influenced by the strong climate gradients on many islands, and how modern island erosion rates compare to long-term rates. Here, we present new measurements of erosion rates over 5 yr to 5 m.y. timescales on the Hawaiian island of Kaua‘i, across which mean annual precipitation ranges from 0.5 to 9.5 m/yr. Eroded rock volumes from basins across Kaua‘i indicate that million-year-scale erosion rates are correlated with modern mean annual precipitation and range from 8 to 335 t km–2 yr–1. In Kaua‘i’s Hanalei River basin, 3He concentrations in detrital olivines imply millennial-scale erosion rates of >126 to >390 t km–2 yr–1 from olivine-bearing hillslopes, while fluvial suspended sediment fluxes measured from 2004 to 2009 plus estimates of chemical and bed-load fluxes imply basin-averaged erosion rates of 545 ± 128 t km–2 yr–1. Mapping of landslide scars in satellite imagery of the Hanalei basin from 2004 and 2010 implies landslide-driven erosion rates of 30–47 t km–2 yr–1. These measurements imply that modern erosion rates in the Hanalei basin are no more than 2.3 ± 0.6 times faster than millennial-scale erosion rates, and, to the extent that modern precipitation patterns resemble long-term patterns, they are consistent with a link between precipitation rates and long-term erosion rates.

Partial nitrification in an air-lift reactor with long-term feeding of increasing ammonium concentrations.

PubMed

Chai, Li-Yuan; Ali, Mohammad; Min, Xiao-Bo; Song, Yu-Xia; Tang, Chong-Jian; Wang, Hai-Ying; Yu, Cheng; Yang, Zhi-Hui

2015-06-01

The partial nitrification (PN) performance under high ammonium concentrations was evaluated in an airlift reactor (ALR). The ALR was operated for 253days with stepwise elevation of ammonium concentration to 1400mg/L corresponding nitrogen loading rate of 2.1kg/m(3)/d. The ammonium removal rate was finally developed to 2.0kg/m(3)/d with average removal efficiency above 91% and nitrite accumulation percentage of 80%. Results showed that the combined effect of limited DO, high bicarbonate, pH and free ammonia (FA) contributed to the stable nitrite accumulation substantially. The biomass in the ALR was improved with the inception of granulation. Precipitates on biomass surface was unexpectedly experienced which might improve the settleability of PN biomass. Organic functional groups attached to the PN biomass suggested the possible absorbability to different types of pollutant. The results provided important evidence for the possibility of applying an ALR to treat high strength ammonium wastewater. Copyright © 2015 Elsevier Ltd. All rights reserved.

Assessments of the efficacy of a long-term application of a phytoremediation system using hybrid poplar trees at former oil tank farm sites.

PubMed

El-Gendy, Ahmed S; Svingos, Sotero; Brice, Donald; Garretson, Joel H; Schnoor, Jerald

2009-05-01

A poplar tree-phytoremediation system was installed at former refinery and tank farm sites in Cabin Creek, West Virginia, to cleanup petroleum-contaminated-soils and groundwater. Groundwater and soils in both sites were sampled and analyzed on a regular basis to monitor changes in contaminant concentration since 1999. The concentration of benzene, toluene, ethylbenzene, xylene, and gasoline range organics (GRO) decreased an average of 81%, 90%, 67%, 78%, and 82%, respectively, in the lower soil horizons and 34%, 84%, 12%, 19%, and 59%, respectively, in groundwater. In addition, concentrations of oxygen, methane, and carbon dioxide in soil gas demonstrated that tree roots dewatered soils and allowed penetration of oxygen deep into the soil profile, creating necessary conditions for rhizosphere bioremediation. Although required clean-up time can limit phytoremediation, it has proven to be a cost-effective strategy for site improvement if imminent pathways for human exposure and risk are not an issue.

Release of cobalt and chromium ions into the serum following implantation of the metal-on-metal Maverick-type artificial lumbar disc (Medtronic Sofamor Danek).

PubMed

Zeh, Alexander; Planert, Michael; Siegert, Gabriele; Lattke, Peter; Held, Andreas; Hein, Werner

2007-02-01

Cross-sectional study of 10 patients to measure the serum levels of cobalt and chromium after TDA. To investigate the release of cobalt and chromium ions into the serum following implantation of the metal-on-metal Maverick-type artificial lumbar disc. In total hip endoprosthetics and consequently for TDA (total disc arthroplasty), metal-on-metal combinations are used with the aim of reducing wear debris. In metal-on-metal TDA the release of metal ions has until now been secondary to the main discussion. We investigated the serum cobalt and chromium concentration following implantation of 15 Maverick TDAs (monosegmental L5-S1, n = 5; bisegmental L4-L5 and L5-S1, n = 5; average age, 36.5 years). Five healthy subjects (no metal implants) acted as a control group. The measurements of the metals were carried out using the HITACHI Z-8200 AAS polarized Zeeman atomic absorption spectrometer after an average of 14.8 months. The concentrations of cobalt and chromium ions in the serum amounted on average to 4.75 microg/L (SD, 2.71) for cobalt and 1.10 microg/L (SD, 1.24) for chromium. Compared with control group, both the chromium and cobalt levels in the serum showed significant increases (Mann-Whitney U test, P = 0.0120). At follow-up,the Oswestry Disability Score was on average significantly decreased by 24.4 points (L5-S1) (t test, P < 0.05) and by 26.8 points (L4-S1) (t test, P < 0.05). The improved clinical situation is also represented by a significant decrease of the Visual Analog Pain Scale of 42.2 points after the follow-up (t test, P < 0.05). Significant systemic release of Cr/Co was proven in the serum compared with the control group. The concentrations of Cr/Co measured in the serum are similar in terms of their level to the values measured in THA metal-on-metal combinations or exceed these values given in the literature. Long-term implication of this metal exposure is unknown and should be studied further.

Long-term exposure to ambient ozone and mortality: a quantitative systematic review and meta-analysis of evidence from cohort studies.

PubMed

Atkinson, R W; Butland, B K; Dimitroulopoulou, C; Heal, M R; Stedman, J R; Carslaw, N; Jarvis, D; Heaviside, C; Vardoulakis, S; Walton, H; Anderson, H R

2016-02-23

While there is good evidence for associations between short-term exposure to ozone and a range of adverse health outcomes, the evidence from narrative reviews for long-term exposure is suggestive of associations with respiratory mortality only. We conducted a systematic, quantitative evaluation of the evidence from cohort studies, reporting associations between long-term exposure to ozone and mortality. Cohort studies published in peer-reviewed journals indexed in EMBASE and MEDLINE to September 2015 and PubMed to October 2015 and cited in reviews/key publications were identified via search strings using terms relating to study design, pollutant and health outcome. Study details and estimate information were extracted and used to calculate standardised effect estimates expressed as HRs per 10 ppb increment in long-term ozone concentrations. 14 publications from 8 cohorts presented results for ozone and all-cause and cause-specific mortality. We found no evidence of associations between long-term annual O3 concentrations and the risk of death from all causes, cardiovascular or respiratory diseases, or lung cancer. 4 cohorts assessed ozone concentrations measured during the warm season. Summary HRs for cardiovascular and respiratory causes of death derived from 3 cohorts were 1.01 (95% CI 1.00 to 1.02) and 1.03 (95% CI 1.01 to 1.05) per 10 ppb, respectively. Our quantitative review revealed a paucity of independent studies regarding the associations between long-term exposure to ozone and mortality. The potential impact of climate change and increasing anthropogenic emissions of ozone precursors on ozone levels worldwide suggests further studies of the long-term effects of exposure to high ozone levels are warranted. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Toxicological Assessment of the International Space Station Atmosphere with Emphasis on Metox Canister Regeneration

NASA Technical Reports Server (NTRS)

James, John T.; Limero, Tom; Beck, Steve; Martin, Millie; Covington, Phillip; Boyd, John; Peters, Randy

2003-01-01

Space-faring crews must have safe breathing air throughout their missions to ensure adequate performance and good health. Toxicological assessment of air quality depends on the standards that define acceptable air quality, measurements of pollutant levels during the flight, and reports from the crew on their in-flight perceptions of air quality. Air samples returned from ISS on flights 8A, UF2, 9A, and 11A were analyzed for trace pollutants. On average, the air during this period of operations was safe for human respiration. However, about 3 hours into the regeneration of 2 Metox canisters in the U.S. airlock on 20 February 2002 the crew reported an intolerable odor that caused them to stop the regeneration, take refuge in the Russian segment, and scrub air in the U.S. segment for 30 hours. Analytical data from grab samples taken during the incident showed that the pollutants released were characteristic of nominal air pollutants, but were present in much higher concentrations. The odors reported by the crew were due to relatively high concentrations of n-butanol, and possibly other pollutants in the mixture. Later data taken during regeneration of Metox canisters that had not been subject to long-term flows showed minimal effects on air quality. Long-term trending data suggest that a disruption in atmospheric mixing between the Service Module and the U.S. Laboratory has occurred and that formaldehyde concentrations are gradually increasing in the U.S. Laboratory. Trending data also show that the releases of octafluoropropane (OFP) have subsided.

The meaning and mental health consequences of long-term immigration detention for people seeking asylum.

PubMed

Coffey, Guy J; Kaplan, Ida; Sampson, Robyn C; Tucci, Maria Montagna

2010-06-01

The aim of the present research was to examine the experience of extended periods of immigration detention from the perspective of previously detained asylum seekers and to identify the consequences of these experiences for life after release. The study sample comprised seventeen adult refugees (sixteen male and one female; average age 42 years), who had been held in immigration detention funded by the Australian government for on average three years and two months. They were interviewed on average three years and eight months following their release and had been granted permanent visa status or such status was imminent. The study employed a combination of qualitative and quantitative methods to explore detention and post-detention experiences, and mental health some years after release. The qualitative component consisted of semi-structured interviews exploring psychological well-being, daily life, significant events, relationships, and ways of coping throughout these periods. This was supplemented with standardised quantitative measures of current mental health and quality of life. All participants were struggling to rebuild their lives in the years following release from immigration detention, and for the majority the difficulties experienced were pervasive. Participants suffered an ongoing sense of insecurity and injustice, difficulties with relationships, profound changes to view of self and poor mental health. Depression and demoralisation, concentration and memory disturbances, and persistent anxiety were very commonly reported. Standardised measures found high rates of depression, anxiety, PTSD and low quality of life scores. The results strongly suggest that the psychological and interpersonal difficulties participants were suffering at the time of interview were the legacy of their adverse experiences while detained. The current study assists in identifying the characteristics of prolonged immigration detention producing long-term psychological harm. Copyright 2010 Elsevier Ltd. All rights reserved.

Analysis of Ozone Trends and Spatial Variations in the North American Lower and Middle Troposphere from a Long-term Ozone Climatology Dataset

NASA Astrophysics Data System (ADS)

Liu, J.; Tarasick, D. W.; Mao, H.; Li, Y., , Dr; Osman, M.; Zhao, T.; Jung, J.; Fioletov, V.; Moeini, O.

2017-12-01

Ozone trends and spatial variations in the North American free troposphere from the 1970s to the 2000s are characterized, based on the newly developed Trajectory-mapped Ozonesonde dataset for the Stratosphere and Troposphere (TOST). TOST uses a special domain-filling technique with forward and backward trajectory calculations to fill in spatial gaps in ozonesonde data. TOST is resolved in latitude, longitude, and altitude so it can provide new information on the long-term variations of troposheric ozone in three dimensions. . Global trend calculations with sparse and irregularly-spaced ozonesonde data must contend with the problem of how to properly weight the data in a zonal or regional average. As TOST spreads the data according to dynamic meteorological information, in a zonal or regional average it will therefore weight the data according to the meteorologically-determined area that each site samples. Through four decades, the highest ozone concentrations in the lower and middle troposphere generally appeared over the central midlatitudes of North America. Longitudinally, ozone was lowest over the southern Pacific Ocean, intermediate over the North American continent, and highest in the outflow along the east coast. The overall ozone trends in the four decades averaged over North America are positive. In particular, there has been an increasing trend at high latitudes between 50-90°N in the North American middle troposphere. Our analysis suggests that this may be caused by influences from the stratosphere and from lower latitudes during the period. The trends from TOST are compared with the original ozonesonde data at selected stations and both datasets correlate closely.

Effect of membrane filtration artifacts on dissolved trace element concentrations

USGS Publications Warehouse

Horowitz, Arthur J.; Elrick, Kent A.; Colberg, Mark R.

1992-01-01

Among environment scientists, the current and almost universally accepted definition of dissolved constituents is an operational one; only those materials which pass through a 0.45-??m membrane filter are considered to be dissolved. Detailed laboratory and field studies on Fe and Al indicate that a number of factors associated with filtration, other than just pore size, can substantially alter 'dissolved' trace element concentrations; these include: filter type, filter diameter, filtration method, volume of sample processed, suspended sediment concentration, suspended sediment grain-size distribution, concentration of colloids and colloidally associated trace elements and concentration of organic matter. As such, reported filtered-water concentrations employing the same pore size filter may not be equal. Filtration artifacts may lead to the production of chemical data that indicate seasonal or annual 'dissolved' chemical trends which do not reflect actual environmental conditions. Further, the development of worldwide averages for various dissolved chemical constituents, the quantification of geochemical cycles, and the determination of short- or long-term environmental chemical trends may be subject to substantial errors, due to filtration artifacts, when data from the same or multiple sources are combined. Finally, filtration effects could have a substantial impact on various regulatory requirements.

The effect of membrane filtration artifacts on dissolved trace element concentrations

USGS Publications Warehouse

Horowitz, A.J.; Elrick, K.A.; Colberg, M.R.

1992-01-01

Among environment scientists, the current and almost universally accepted definition of dissolved constituents is an operational one only those materials which pass through a 0.45-??m membrane filter are considered to be dissolved. Detailed laboratory and field studies on Fe and Al indicate that a number of factors associated with filtration, other than just pore size, can substantially alter 'dissolved' trace element concentrations; these include: filter type, filter diameter, filtration method, volume of sample processed, suspended sediment concentration, suspended sediment grain-size distribution, concentration of colloids and colloidally-associated trace elements and concentration of organic matter. As such, reported filtered-water concentrations employing the same pore size filter may not be equal. Filtration artifacts may lead to the production of chemical data that indicate seasonal or annual 'dissolved' chemical trends which do not reflect actual environmental conditions. Further, the development of worldwide averages for various dissolved chemical constituents, the quantification of geochemical cycles, and the determination of short- or long-term environmental chemical trends may be subject to substantial errors, due to filtration artifacts, when data from the same or multiple sources are combined. Finally, filtration effects could have a substantial impact on various regulatory requirements.

Long-term Exposure to PM2.5 and Mortality Among Older Adults in the Southeastern US.

PubMed

Wang, Yan; Shi, Liuhua; Lee, Mihye; Liu, Pengfei; Di, Qian; Zanobetti, Antonella; Schwartz, Joel D

2017-03-01

Little is known about what factors modify the effect of long-term exposure to PM2.5 on mortality, in part because in most previous studies certain groups such as rural residents and individuals with lower socioeconomic status (SES) are under-represented. We studied 13.1 million Medicare beneficiaries (age ≥65) residing in seven southeastern US states during 2000-2013 with 95 million person-years of follow-up. We predicted annual average of PM2.5 in each zip code tabulation area (ZCTA) using a hybrid spatiotemporal model. We fit Cox proportional hazards models to estimate the association between long-term PM2.5 and mortality. We tested effect modification by individual-level covariates (race, sex, eligibility for both Medicare and Medicaid, and medical history), neighborhood-level covariates (urbanicity, percentage below poverty level, lower education, median income, and median home value), mean summer temperature, and mass fraction of 11 PM2.5 components. The hazard ratio (HR) for death was 1.021 (95% confidence interval: 1.019, 1.022) per 1 μg m increase in annual PM2.5. The HR decreased with age. It was higher among males, non-whites, dual-eligible individuals, and beneficiaries with previous hospital admissions. It was higher in neighborhoods with lower SES or higher urbanicity. The HR increased with mean summer temperature. The risk associated with PM2.5 increased with relative concentration of elemental carbon, vanadium, copper, calcium, and iron and decreased with nitrate, organic carbon, and sulfate. Associations between long-term PM2.5 exposure and death were modified by individual-level, neighborhood-level variables, temperature, and chemical compositions.

Effect of long-term exposure of 2.4 GHz radiofrequency radiation emitted from Wi-Fi equipment on testes functions.

PubMed

Dasdag, Suleyman; Taş, Muzaffer; Akdag, Mehmet Zulkuf; Yegin, Korkut

2015-03-01

The aim of this study was to investigate long-term effects of radiofrequency radiation (RFR) emitted from a Wireless Fidelity (Wi-Fi) system on testes. The study was carried out on 16 Wistar Albino adult male rats by dividing them into two groups such as sham (n: 8) and exposure (n: 8). Rats in the exposure group were exposed to 2.4 GHz RFR radiation for 24 h/d during 12 months (1 year). The same procedure was applied to the rats in the sham control group except the Wi-Fi system was turned off. Immediately after the last exposure, rats were sacrificed and reproductive organs were removed. Motility (%), concentration (×10(6)/mL), tail defects (%), head defects (%) and total morphologic defects (%) of sperms and weight of testes (g), left epididymis (g), prostate (g), seminal vesicles (g) were determined. Seminiferous tubules diameter (μm) and tunica albuginea thickness (μm) were also measured. However, the results were evaluated by using Johnsen's score. Head defects increased in the exposure group (p < 0.05) while weight of the epididymis and seminal vesicles, seminiferous tubules diameter and tunica albuginea thickness were decreased in the exposure group (p < 0.01, p < 0.001, p < 0.0001). However, other alterations of other parameters were not found significant (p > 0.05). In conclusion, we observed that long-term exposure of 2.4 GHz RF emitted from Wi-Fi (2420 μW/kg, 1 g average) affects some of the reproductive parameters of male rats. We suggest Wi-Fi users to avoid long-term exposure of RF emissions from Wi-Fi equipment.

Ambient air pollution, lung function and airway responsiveness in children with asthma

PubMed Central

Ierodiakonou, Despo; Zanobetti, Antonella; Coull, Brent A.; Melly, Steve; Postma, Dirkje S.; Boezen, H. Marike; Vonk, Judith M.; Williams, Paul V.; Shapiro, Gail G.; McKone, Edward F.; Hallstrand, Teal S.; Koenig, Jane Q.; Schildcrout, Jonathan S.; Lumley, Thomas; Fuhlbrigge, Anne N.; Koutrakis, Petros; Schwartz, Joel; Weiss, Scott T.; Gold, Diane R

2016-01-01

Background Although ambient air pollution has been linked to reduced lung function in healthy children, longitudinal analyses of pollution effects in asthma are lacking. Objective To investigate pollution effects in a longitudinal asthma study and effect modification by controller medications. Methods We examined associations of lung function and methacholine responsiveness (PC20) with ozone, carbon monoxide (CO), nitrogen dioxide (NO2) and sulfur dioxide (SO2) levels in 1,003 asthmatic children participating in a 4-year clinical trial. We further investigated whether budesonide and nedocromil modified pollution effects. Daily pollutant concentrations were linked to zip/postal code of residence. Linear mixed models tested associations of within-subject pollutant concentrations with FEV1 and FVC %predicted, FEV1/FVC and PC20, adjusting for seasonality and confounders. Results Same-day and 1-week average CO levels were negatively associated with post-bronchodilator %predicted FEV1 (change(95%CI) per IQR: −0.33(−0.49, −0.16), −0.41(−0.62, −0.21), respectively) and FVC (−0.19(−0.25, −0.07), −0.25(−0.43, −0.07)). Longer-term four-month averages of CO were negatively associated with prebronchodilator %predicted FEV1 and FVC (−0.36(−0.62, −0.10), −0.21(−0.42, −0.01)). Four-month averaged CO and ozone levels were negatively associated with FEV1/FVC (p<0.05). Increased four-month average NO2 levels were associated with reduced post-bronchodilator FEV1 and FVC %predicted. Long-term exposures to SO2 were associated with reduced PC20 (%change(95%CI) per IQR:-6(-11,-1.5)). Treatment augmented the negative short-term CO effect on PC20. Conclusions Air pollution adversely influences lung function and PC20 in asthmatic children. Treatment with controller medications may not protect but worsens the CO effects on PC20. This clinical trial design evaluates modification of pollution effects by treatment without confounding by indication. PMID:26187234

Global synthesis of long-term cloud condensation nuclei observations

NASA Astrophysics Data System (ADS)

Schmale, Julia; Henning, Silvia; Stratmann, Frank; Henzing, Bas; Schlag, Patrick; Aalto, Pasi; Keskinen, Helmi; Sellegri, Karine; Ovadnevaite, Jurgita; Krüger, Mira; Jefferson, Anne; Whitehead, James; Carslaw, Ken; Yum, Seong Soo; Kristensson, Adam; Baltensperger, Urs; Gysel, Martin

2016-04-01

Cloud condensation nuclei (CCN) are aerosol particles with the ability to activate into droplets at a given super saturation and therefore influence the microphysical and optical properties of clouds. To predict cloud radiative properties understanding the spatial and temporal variability of CCN concentrations in different environments is important. However, currently, the effects of atmospheric particles on changes in cloud radiative forcing are still the largest contribution of uncertainty in climate forcing prediction (IPCC, 2013). Numerous intensive field campaigns have already explored detailed characteristics of CCN in many locations around the world. However, these rather short-term observations can generally not address seasonal or inter-annual variations and a comparison between campaign sites is difficult due to the higher influence of specific environmental circumstances on short-term measurements results. Here, we present results of more long-term CCN and aerosol number concentrations as well as size distribution data covering at least one full year between 2006 and 2014. The 12 locations include ACTRIS stations (http://www.actris.net/) in Europe, and further sites in North America, Brazil and Korea. The sites are located in different environments allowing for temporal and spatial characterization of CCN variability in different atmospheric regimes. Those include marine, remote-continental, boreal forest, rain forest, Arctic and monsoon-influenced environments, as well as boundary layer and free tropospheric conditions. The aerosol populations and their activation behavior show significant differences across the stations. While peak concentrations of CCN are observed in summer at the high altitude sites, in the Arctic the highest concentrations occur during the Haze period in spring. The rural-marine and rural-continental sites exhibit similar CCN concentration characteristics with a relatively flat annual cycle. At some stations, e.g. in the boreal environment, the annual cycle is more pronounced for higher SS. Geometric mean diameters of aerosol populations as well as the activation ratios on the basis of particles > 50 nm vary strongly among sites and throughout the seasons. Additionally, autocorrelation analysis is performed to investigate the persistence of variables over different timescales and to explore meaningful averaging periods for global modelling of CCN. In terms of CCN persistence, we find three different regimes: (1) CCN concentrations persist for a week or longer showing also seasonal patterns. (2) CCN concentrations persist for less than one week and there is little seasonal pattern. And (3) CCN concentrations are highly variable and do not persist longer than 2 days but show seasonal cycles. Several but not all sites show diurnal cycles. These different behaviors are influenced by environmental factors such as rainy seasons in the Amazon or Korea (monsoon) but also by anthropogenic pollution episodes such as during the Arctic Haze period.

Comparing polychlorinated biphenyl concentrations and patterns in the Saginaw River using sediment, caged fish, and semipermeable membrane devices

USGS Publications Warehouse

Echols, K.R.; Gale, R.W.; Schwartz, T.R.; Huckins, J.N.; Williams, L.L.; Meadows, J.C.; Morse, D.; Petty, J.D.; Orazio, C.E.; Tillitt, D.E.

2000-01-01

Three techniques of assessing bioavailable polychlorinated biphenyls (PCBs) in the Saginaw River, MI, were compared: sediments, caged fish, and semipermeable membrane devices (SPMDs). SPMDs and caged fish were placed in the river for 28 days at five sites where sediments were also sampled. The samples were analyzed for PCB congeners to determine concentrations and patterns. Total PCB concentrations ranged from 33 to 280 ng/g (dry weight) in sediments, 46 to 290 ng/g (wet weight) in caged fish, and 77 to 790 ng/g in SPMDs. Previously reported rates of PCB accumulation by SPMDs were used to estimate aqueous concentrations from the PCB concentrations detected in the SPMDs. Sediment-water partition coefficients were used to estimate aqueous PCB concentrations from sediment. Steady-state bioconcentration factors and depuration rate constants were used to estimate dissolved PCB concentrations from caged channel catfish. Relative PCB patterns from the SPMDs, caged fish, and sediment were compared using principal components analysis. SPMD and sediment samples provide complementary information. Sediments reflect long-term accumulation and weathering, while SPMDs integrate water concentrations only during the sampling period. Because of higher water solubilities of lower-chlorinated PCBs these predominate in the SPMDs as compared to in the fish and sediments. Contaminant profile differences between caged fish and SPMDs are likely due to metabolism and depuration of certain PCB congeners by fish.Three techniques of assessing bioavailable polychlorinated biphenyls (PCBs) in the Saginaw River, Ml, were compared: sediments, caged fish, and semipermeable membrane devices (SPMDs). SPMDs and caged fish were placed in the river for 28 days at five sites where sediments were also sampled. The samples were analyzed for PCB congeners to determine concentrations and patterns. Total PCB concentrations ranged from 33 to 280 ng/g (dry weight) in sediments, 46 to 290 ng/g (wet weight) in caged fish, and 77 to 790 ng/g in SPMDs. Previously reported rates of PCB accumulation by SPMDs were used to estimate aqueous concentrations from the PCB concentrations detected in the SPMDs. Sediment-water partition coefficients were used to estimate aqueous PCB concentrations from sediment. Steady-state bioconcentration factors and depuration rate constants were used to estimate dissolved PCB concentrations from caged channel catfish. Relative PCB patterns from the SPMDs, caged fish, and sediment were compared using principal components analysis. SPMD and sediment samples provide complementary information. Sediments reflect long-term accumulation and weathering, while SPMDs integrate water concentrations only during the sampling period. Because of higher water solubilities of lower-chlorinated PCBs these predominate in the SPMDs as compared to in the fish and sediments. Contaminant profile differences between caged fish and SPMDs are likely due to metabolism and depuration of certain PCB congeners by fish.At five sites in the Saginaw River, MI, PCB concentrations were determined in the summer of 1993 using three methods: sediment analysis, concentrations in caged fish, and concentrations in semipermeable membrane devices (SPMDs). On average, total PCB concentrations in the SPMDs were twice those found in caged fish, and the SPMD-to-fish concentration ratios of di-, tri-, tetra-, and pentaCB homologues were 10.0, 3.0, 2.5, and 1.4, respectively. Average concentrations in the sediments were approximately half those in the SPMDs, and the caged fish showed a greater preponderance of higher log octanol-water partition coefficient PCBs similar to the sediment pattern. On average, the water PCB concentrations estimated from sediment concentrations were five times higher than those calculated from SPMDs and three times higher than those estimated from caged fish. The total PCB concentrations in sediment, caged fish, and SPMDs ranged 33-280, 46-290, and 77-790 ng/g, respectiv

Hydroelectric production from Brazil's São Francisco River could cease due to climate change and inter-annual variability.

PubMed

de Jong, Pieter; Tanajura, Clemente Augusto Souza; Sánchez, Antonio Santos; Dargaville, Roger; Kiperstok, Asher; Torres, Ednildo Andrade

2018-09-01

By the end of this century higher temperatures and significantly reduced rainfall are projected for the Brazilian North and Northeast (NE) regions due to Global Warming. This study examines the impact of these long-term rainfall changes on the Brazilian Northeast's hydroelectric production. Various studies that use different IPCC models are examined in order to determine the average rainfall reduction by the year 2100 in comparison to baseline data from the end of the 20th century. It was found that average annual rainfall in the NE region could decrease by approximately 25-50% depending on the emissions scenario. Analysis of historical rainfall data in the São Francisco basin during the last 57years already shows a decline of more than 25% from the 1961-90 long-term average. Moreover, average annual rainfall in the basin has been below its long-term average every year bar one since 1992. If this declining trend continues, rainfall reduction in the basin could be even more severe than the most pessimistic model projections. That is, the marked drop in average rainfall projected for 2100, based on the IPCC high emissions scenario, could actually eventuate before 2050. Due to the elasticity factor between rainfall and streamflow and because of increased amounts of irrigation in the São Francisco basin, the reduction in the NE's average hydroelectric production in the coming decades could be double the predicted decline in rainfall. Conversely, it is estimated that wind power potential in the Brazilian NE will increase substantially by 2100. Therefore both wind and solar power will need to be significantly exploited in order for the NE region to sustainably replace lost hydroelectric production. Copyright © 2018 Elsevier B.V. All rights reserved.

Mass balance, meteorological, ice motion, surface altitude, runoff, and ice thickness data at Gulkana Glacier, Alaska, 1995 balance year

USGS Publications Warehouse

March, Rod S.

2000-01-01

The 1995 measured winter snow, maximum winter snow, net, and annual balances in the Gulkana Glacier basin were evaluated on the basis of meteorological, hydrological, and glaciological data obtained in the basin. Averaged over the glacier, the measured winter snow balance was 0.94 meter on April 19, 1995, 0.6 standard deviation below the long-term average; the maximum winter snow balance, 0.94 meter, was reached on April 25, 1995; the net balance (from September 18, 1994 to August 29, 1995) was -0.70 meter, 0.76 standard deviation below the long-term average. The annual balance (October 1, 1994, to September 30, 1995) was -0.86 meter. Ice-surface motion and altitude changes measured at three index sites document seasonal ice speed and glacier-thickness changes. Annual stream runoff was 2.05 meters averaged over the basin, approximately equal to the long-term average. The 1976 ice-thickness data are reported from a single site near the highest measurement site (180 meters thick) and from two glacier cross profiles near the mid-glacier (270 meters thick on centerline) and low glacier (150 meters thick on centerline) measurement sites. A new area-altitude distribution determined from 1993 photogrammetry is reported. Area-averaged balances are reported from both the 1967 and 1993 area-altitude distribution so the reader may directly see the effect of the update. Briefly, loss of ablation area between 1967 and 1993 results in a larger weighting being applied to data from the upper glacier site and hence, increases calculated area-averaged balances. The balance increase is of the order of 15 percent for net balance.

Exposure to airborne asbestos during removal and installation of gaskets and packings: a review of published and unpublished studies.

PubMed

Madl, Amy K; Clark, Katherine; Paustenbach, Dennis J

2007-01-01

In recent years, questions have been raised about the health risks to persons who have been occupationally exposed to asbestos-containing gaskets and packing materials used in pipes, valves, and machinery (pumps, autos, etc.). Up until the late 1970s, these materials were widely used throughout industrial and maritime operations, refineries, chemical plants, naval ships, and energy plants. Seven simulation studies and four work-site industrial hygiene studies of industrial and maritime settings involving the collection of more than 300 air samples were evaluated to determine the likely airborne fiber concentrations to which a worker may have been exposed while working with encapsulated asbestos-containing gaskets and packing materials. Each study was evaluated for the representativeness of work practices, analytical methods, sample size, and potential for asbestos contamination (e.g., insulation on valves or pipes used in the study). Specific activities evaluated included the removal and installation of gaskets and packings, flange cleaning, and gasket formation. In all but one of the studies relating to the replacement of gaskets and packing using hand-held tools, the short-term average exposures were less than the current 30-min OSHA excursion limit of 1 fiber per cubic centimeter (f/cc) and all of the long-term average exposures were less than the current 8-h permissible exposure limit time-weighted average (PEL-TWA) of 0.1 f/cc. The weight of evidence indicates that the use of hand tools and hand-operated power tools to remove or install gaskets or packing as performed by pipefitters or other tradesmen in nearly all plausible situations would not have produced airborne concentrations in excess of contemporaneous regulatory levels.

Climate Factors Contributing to Streamflow Inputs and Extreme Water-level Deviations from Long-term Averages for Lakes Superior and Michigan-Huron

NASA Astrophysics Data System (ADS)

Anderson, M. T.; Stamm, J. F.

2014-12-01

The Great Lakes are a highly valued freshwater resource of the United States and Canada. The Lakes are the focus of a science-based restoration program, known as the Great Lakes Restoration Initiative (GLRI). Physical and chemical factors, such as inflows and nutrient loads to the Great Lakes can affect ecosystem function, contribute to the spread of invasive species and increase the occurrence of harmful algal blooms. Since about 1999, water levels in Lakes Superior and Michigan-Huron have been at or below the long-term average (1918 to present). Analyses of streamflow trends for the period 1960 to 2012 in watersheds draining into Lakes Superior and Michigan-Huron showed a long-term decline in average inflows, which helps to explain the persistently below-average lake levels. Recent climatic conditions of October 2013 to August 2014 have contributed to a rapid rise in lake levels, most notably in Lake Superior. Lake Superior recently reached an elevation of 602.56 feet above sea level in August 2014, which is the highest level in 17 years. Coincident with this recovery was the development of a large algal bloom in Lake Erie in August of 2014 that shut down the Toledo, Ohio municipal water supply. These anomalous, extreme deviations from long-term average lake levels will be examined to better understand the forcing factors that contributed to changes in inflow volumes and lake-levels. Particular focus will be given to the climatology of years when changes in lake levels are most pronounced, such as; the measured lake-level declines during 1964-1965 and 1998-2000; and lake-level rises during 1973-1974, 1987-1989, and 2013-2014. The climatology of years with periods of algal blooms will also be examined such as, 2003, 2008, 2011 and 2014.

Gained insights from combined high-frequency and long-term water quality monitoring in agricultural catchments

NASA Astrophysics Data System (ADS)

Jomaa, Seifeddine; Dupas, Rémi; Musolff, Andreas; Rozemeijer, Joachim; Borchardt, Dietrich; Rode, Michael

2017-04-01

Despite extensive efforts to reduce nitrate (NO3) transfer in agricultural areas, the NO3 concentration in rivers often changes little. To investigate the reasons for this limited response, NO3 dynamics in a 100 km2 agricultural catchment in eastern Germany was analysed from decadal to infra-hourly time scales. First, Dynamic Harmonic Regression (DHR) analysis of a 32-year (1982-2014) record of NO3 and discharge revealed that i) the long-term trend in NO3 concentration was closely related to that in discharge, suggesting that large-scale weather and climate patterns were masking the effect of improved nitrogen management on NO3 trends; ii) maximum winter and minimum summer concentrations had a persistent seasonal pattern, which was interpreted as a dynamic NO3 concentration from the soil and subsoil columns; and iii) the catchment progressively changed from chemodynamic to more chemostatic behaviour over the three decades of study, which is a sign of long-term homogenisation of NO3 concentrations in the profile. Second, infra-hourly (15 min time interval) analysis of storm-event dynamics during a typical hydrological year (2005-2006) was performed to identify periods of the year with high leaching risk and to link the latter to agricultural management practices in the catchment. Also, intra-hourly data was used to improve NO3 load estimation during storm events. An Event Response Reconstruction (ERR) model was built using NO3 concentration response descriptor variables and predictor variables deduced from discharge and precipitation records. The ERR approach significantly improved NO3 load estimates compared to linear interpolation of grab-sampling data (error was reduced from 10 to 1%). Finally, this study shows that detailed physical understanding of NO3 dynamics across time scales can be obtained only through combined analysis of long-term records and high-resolution sensor data. Hence, a joint effort is advocated between environmental authorities, who usually perform long-term monitoring, and scientific programmes, which usually perform high-resolution monitoring.

RELATIONSHIPS BETWEEN SUMMER CONCENTRATIONS OF TOTAL NITROGEN AND CHLOROPHYLL A IN TEN COASTAL SYSTEMS IN THE EASTERN UNITED STATES

EPA Science Inventory

We have examined relationships between summer (JuneAugust) average concentrations of total nitrogen (TN) and chlorophyll a (chl a) concentrations in the near-shore Mid-Atlantic Bight and nine bays and estuaries in the eastern United States: Boston Harbor/Massachusetts Bay, Long I...

A source study of atmospheric polycyclic aromatic hydrocarbons in Shenzhen, South China.

PubMed

Liu, Guoqing; Tong, Yongpeng; Luong, John H T; Zhang, Hong; Sun, Huibin

2010-04-01

Air pollution has become a serious problem in the Pearl River Delta, South China, particularly in winter due to the local micrometeorology. In this study, atmospheric polycyclic aromatic hydrocarbons (PAHs) were monitored weekly in Shenzhen during the winter of 2006. Results indicated that the detected PAHs were mainly of vapor phase compounds with phenanthrene dominant. The average vapor phase and particle phase PAHs concentration in Shenzhen was 101.3 and 26.7 ng m( - 3), respectively. Meteorological conditions showed great effect on PAH concentrations. The higher PAHs concentrations observed during haze episode might result from the accumulation of pollutants under decreased boundary layer, slower wind speed, and long-term dryness conditions. The sources of PAHs in the air were estimated by principal component analysis in combination with diagnostic ratios. Vehicle exhaust was the major PAHs source in Shenzhen, accounting for 50.0% of the total PAHs emissions, whereas coal combustion and solid waste incineration contributed to 29.4% and 20.6% of the total PAHs concentration, respectively. The results clearly indicated that the increasing solid waste incinerators have become a new important PAHs source in this region.

High risks of lung disease associated with early-life and moderate lifetime arsenic exposure in northern Chile.

PubMed

Steinmaus, Craig; Ferreccio, Catterina; Acevedo, Johanna; Balmes, John R; Liaw, Jane; Troncoso, Patricia; Dauphiné, David C; Nardone, Anthony; Smith, Allan H

2016-12-15

Arsenic in drinking water has been associated with increases in lung disease, but information on the long-term impacts of early-life exposure or moderate exposure levels are limited. We investigated pulmonary disease and lung function in 795 subjects from three socio-demographically similar areas in northern Chile: Antofagasta, which had a well-described period of high arsenic water concentrations (860μg/L) from 1958 to 1970; Iquique, which had long-term arsenic water concentrations near 60μg/L; and Arica, with long-term water concentrations ≤10μg/L. Compared to adults never exposed >10μg/L, adults born in Antofagasta during the high exposure period had elevated odds ratios (OR) of respiratory symptoms (e.g., OR for shortness of breath=5.56, 90% confidence interval (CI): 2.68-11.5), and decreases in pulmonary function (e.g., 224mL decrease in forced vital capacity in nonsmokers, 90% CI: 97-351mL). Subjects with long-term exposure to arsenic water concentrations near 60μg/L also had increases in some pulmonary symptoms and reduced lung function. Overall, these findings provide new evidence that in utero or childhood arsenic exposure is associated with non-malignant pulmonary disease in adults. They also provide preliminary new evidence that long-term exposures to moderate levels of arsenic may be associated with lung toxicity, although the magnitude of these latter findings were greater than expected and should be confirmed. Copyright © 2016 Elsevier Inc. All rights reserved.

High risks of lung disease associated with early-life and moderate lifetime arsenic exposure in northern Chile

PubMed Central

Steinmaus, Craig; Ferreccio, Catterina; Acevedo, Johanna; Balmes, John R; Liaw, Jane; Troncoso, Patricia; Dauphiné, David C; Nardone, Anthony; Smith, Allan H

2016-01-01

Background Arsenic in drinking water has been associated with increases in lung disease, but information on the long-term impacts of early-life exposure or moderate exposure levels are limited. Methods We investigated pulmonary disease and lung function in 795 subjects from three socio-demographically similar areas in northern Chile: Antofagasta, which had a well-described period of high arsenic water concentrations (860 μg/L) from 1958–1970; Iquique, which had long-term arsenic water concentrations near 60 μg/L; and Arica, with long-term water concentrations ≤10 μg/L. Results Compared to adults never exposed >10 μg/L, adults born in Antofagasta during the high exposure period had elevated odds ratios (OR) of respiratory symptoms (e.g., OR for shortness of breath = 5.56, 90% confidence interval (CI): 2.68–11.5), and decreases in pulmonary function (e.g., 224 ml decrease in forced vital capacity in nonsmokers, 90% CI: 97–351 ml). Subjects with long-term exposure to arsenic water concentrations near 60 μg/L also had increases in some pulmonary symptoms and reduced lung function. Conclusions Overall, these findings provide new evidence that in utero or childhood arsenic exposure is associated with non-malignant pulmonary disease in adults. They also provide preliminary new evidence that long-term exposures to moderate levels of arsenic may be associated with lung toxicity, although the magnitude of these latter findings were greater than expected and should be confirmed. PMID:27725189

The Glyphosate-Based Herbicide Roundup Does not Elevate Genome-Wide Mutagenesis of Escherichia coli.

PubMed

Tincher, Clayton; Long, Hongan; Behringer, Megan; Walker, Noah; Lynch, Michael

2017-10-05

Mutations induced by pollutants may promote pathogen evolution, for example by accelerating mutations conferring antibiotic resistance. Generally, evaluating the genome-wide mutagenic effects of long-term sublethal pollutant exposure at single-nucleotide resolution is extremely difficult. To overcome this technical barrier, we use the mutation accumulation/whole-genome sequencing (MA/WGS) method as a mutagenicity test, to quantitatively evaluate genome-wide mutagenesis of Escherichia coli after long-term exposure to a wide gradient of the glyphosate-based herbicide (GBH) Roundup Concentrate Plus. The genome-wide mutation rate decreases as GBH concentration increases, suggesting that even long-term GBH exposure does not compromise the genome stability of bacteria. Copyright © 2017 Tincher et al.

Safety and Efficacy of Rivastigmine in Adolescents with Down Syndrome: Long-Term Follow-Up

PubMed Central

Spiridigliozzi, Gail A.; Crissman, Blythe G.; McKillop, Jane Anne; Yamamoto, Haru; Kishnani, Priya S.

2010-01-01

Abstract Following the completion of a 20-week, open-label study of the safety and efficacy of liquid rivastigmine for adolescents with Down syndrome, 5 of the 10 adolescents in the clinical trial continued long-term rivastigmine therapy and 5 did not. After an average period of 38 months, all 10 subjects returned for a follow-up assessment to determine the safety and efficacy of long-term rivastigmine use. Rivastigmine was well tolerated and overall health appeared to be unaffected by long-term rivastigmine use. Performance change on cognitive and language measures administered at the termination of the open-label clinical trial was compared between the two groups. No between-group difference in median performance change across the long-term period was found, suggesting that the long-term use of rivastigmine does not improve cognitive and language performance. However, two subjects demonstrated remarkable improvement in adaptive function over the long-term period. Both subjects had received long-term rivastigmine therapy. The discussion addresses the challenge of assessing cognitive change in clinical trials using adolescents with Down syndrome as subjects and the use of group versus individual data to evaluate the relevance of medication effects. PMID:21186971

Assessment of seasonality in exposure to dioxins, furans and dioxin-like PCBs by using long-term food-consumption data.

PubMed

Feinberg, M; Soler, L; Contenot, S; Verger, P

2011-04-01

According to the European Food Safety Authority (EFSA) guidance related to uncertainties in dietary exposure assessment, exposure assessment based on short-term food-consumption surveys, such as 24-h recalls or 2-day records, tend to overestimate long-term exposure because of the assumption that the dietary pattern will be similar day after day over a lifetime. The aim of this study was to make an assessment of dietary exposure to polychlorinated dibenzodioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs), also called 'dioxins' and 'dioxin-like PCBs', using long-term household purchase and consumption survey data collected by TNS-Secodip. Weekly purchases of the major dioxins and dl-PCB vector products of these contaminants were collected for 328 single-person households, who participated at TNS-Secodip consumption surveys from 2003 to 2005 and who were single-person households in order to estimate better their consumption. These data were combined with average contamination levels of food products. Weekly gross average exposure was estimated at 10.2 pg toxic equivalent (WHO TEQ) kg(-1) bw week(-1) (95% confidence interval [9.6, 10.9]). According to the typical shape of the distribution of individual weekly exposures, it is sensible to fit an exponential law to these data. The mean was therefore 12.1 pg WHO TEQ kg(-1) bw week(-1). This value is higher than the arithmetic mean because it better takes into account inter-individual variability. It was estimated that about 20% of persons in this sample were exceeding the current health-based guidance value mainly due to high consumption of seafood and/or dairy products. Thanks to long survey duration (3 years) and the weekly recording of food consumption, it was possible to demonstrate the actual seasonality of dietary exposure to dioxins and dl-PCBs with a maximum between March and September; similar seasonality is observable for fish consumption. Autoregressive integrated moving average (ARIMA) models were adjusted to the time series and it was demonstrated that the number of times the upper limit of confidence intervals exceeds the provisional tolerable weekly intake (PTWI) is about 15 weeks per year on average. Finally, compared with the results obtained from data collected in the short-term surveys (1 week), this study does not suggest that short-term consumption surveys tend to overestimate the long-term exposure.

7 CFR 634.27 - Cost-share payment.

Code of Federal Regulations, 2010 CFR

2010-01-01

... AGRICULTURE LONG TERM CONTRACTING RURAL CLEAN WATER PROGRAM Participant RCWP Contracts § 634.27 Cost-share... essential for meeting the water quality objectives in the project area. (c) Basis for cost-share payment. (1...) Average cost, or (ii) Actual cost not to exceed average cost. (2) If the average cost at the time of...

7 CFR 634.27 - Cost-share payment.

Code of Federal Regulations, 2014 CFR

2014-01-01

... AGRICULTURE LONG TERM CONTRACTING RURAL CLEAN WATER PROGRAM Participant RCWP Contracts § 634.27 Cost-share... essential for meeting the water quality objectives in the project area. (c) Basis for cost-share payment. (1...) Average cost, or (ii) Actual cost not to exceed average cost. (2) If the average cost at the time of...

7 CFR 634.27 - Cost-share payment.

Code of Federal Regulations, 2013 CFR

2013-01-01

... AGRICULTURE LONG TERM CONTRACTING RURAL CLEAN WATER PROGRAM Participant RCWP Contracts § 634.27 Cost-share... essential for meeting the water quality objectives in the project area. (c) Basis for cost-share payment. (1...) Average cost, or (ii) Actual cost not to exceed average cost. (2) If the average cost at the time of...

7 CFR 634.27 - Cost-share payment.

Code of Federal Regulations, 2011 CFR

2011-01-01

... AGRICULTURE LONG TERM CONTRACTING RURAL CLEAN WATER PROGRAM Participant RCWP Contracts § 634.27 Cost-share... essential for meeting the water quality objectives in the project area. (c) Basis for cost-share payment. (1...) Average cost, or (ii) Actual cost not to exceed average cost. (2) If the average cost at the time of...

7 CFR 634.27 - Cost-share payment.

Code of Federal Regulations, 2012 CFR

2012-01-01

... AGRICULTURE LONG TERM CONTRACTING RURAL CLEAN WATER PROGRAM Participant RCWP Contracts § 634.27 Cost-share... essential for meeting the water quality objectives in the project area. (c) Basis for cost-share payment. (1...) Average cost, or (ii) Actual cost not to exceed average cost. (2) If the average cost at the time of...

The complementary relationship in estimation of regional evapotranspiration: An enhanced Advection-Aridity model

Treesearch

Michael T. Hobbins; Jorge A. Ramirez; Thomas C. Brown

2001-01-01

Long-term monthly evapotranspiration estimates from Brutsaert and Stricker’s Advection-Aridity model were compared with independent estimates of evapotranspiration derived from long-term water balances for 139 undisturbed basins across the conterminous United States. On an average annual basis for the period 1962-1988 the original model, which uses a Penman wind...

Impact of Infection Prevention and Control Initiatives on Acute Respiratory Infections in a Pediatric Long-Term Care Facility

PubMed Central

Murray, Meghan T.; Jackson, Olivia; Cohen, Bevin; Hutcheon, Gordon; Saiman, Lisa; Larson, Elaine; Neu, Natalie

2016-01-01

We evaluated the collective impact of several infection prevention and control initiatives aimed at reducing acute respiratory infections (ARIs) in a pediatric long-term care facility. ARIs did not decrease overall, though the proportion of infections associated with outbreaks and average number of cases per outbreak decreased. Influenza rates decreased significantly. PMID:27053088

Sources of suspended sediment in the Waikele watershed, Oʻahu, Hawaiʻi

USGS Publications Warehouse

Izuka, Scot K.

2012-01-01

Data from streamflow/sediment gages and measurements of changes in channel-bed sediment storage were gathered between October 1, 2007, and September 30, 2010, to assess the sources of suspended sediment in the Waikele watershed, Oʻahu, Hawaiʻi. Streamflow from the watershed averaged 33 cubic feet per second during the study period, with interannual variations corresponding with variations in the frequency and magnitude of storm-flow peaks. Average streamflow during the study period was lower than the long-term average, but the study period included a storm on December 11, 2008, that caused record-high streamflows in parts of the watershed. Suspended-sediment yield from the Waikele watershed during the study period averaged 82,500 tons per year, which is 2.7 times higher than the long-term average. More than 90 percent of the yield during the study period was discharged during the December 11, 2008, storm. The study-period results are consistent with long-term records that show that the vast majority of suspended-sediment transport occurs during a few large storms. Results of this study also show that all but a small percentage of the suspended-sediment yield came from hillslopes. Only a small fraction of bed sediments is fine enough to be transported as suspended load; most bed sediments in the watershed are coarse. Silt and clay constitute less than 3 percent of the bed-sediment volume on average. Some larger clasts, however, can disintegrate during transport and contribute to the suspended load downstream. During the study period, suspended-sediment yield from the urbanized Mililani subbasin averaged 25 tons per year per square mile (tons/yr/mi2), which was much smaller than the yield from any other subbasin; these results indicate that urban land use yields much less sediment than other land uses. The wet, forested Kipapa subbasin had an average normalized hillslope suspended-sediment yield of 386 tons/yr/mi2; the average yield for forested areas in the watershed may be lower. Suspended-sediment yield from agricultural land use in the watershed is estimated to range between 5,590 and 6,440 tons/yr/mi2 during the study period; the long-term average is estimated to be 2,070 to 2,390 tons/yr/mi2. Of the three land uses considered, agriculture had by far the highest normalized suspended-sediment yield during this study - about an order of magnitude higher than forests and two orders of magnitude higher than urban areas.

Effects of different analysis techniques and recording duty cycles on passive acoustic monitoring of killer whales.

PubMed

Riera, Amalis; Ford, John K; Ross Chapman, N

2013-09-01

Killer whales in British Columbia are at risk, and little is known about their winter distribution. Passive acoustic monitoring of their year-round habitat is a valuable supplemental method to traditional visual and photographic surveys. However, long-term acoustic studies of odontocetes have some limitations, including the generation of large amounts of data that require highly time-consuming processing. There is a need to develop tools and protocols to maximize the efficiency of such studies. Here, two types of analysis, real-time and long term spectral averages, were compared to assess their performance at detecting killer whale calls in long-term acoustic recordings. In addition, two different duty cycles, 1/3 and 2/3, were tested. Both the use of long term spectral averages and a lower duty cycle resulted in a decrease in call detection and positive pod identification, leading to underestimations of the amount of time the whales were present. The impact of these limitations should be considered in future killer whale acoustic surveys. A compromise between a lower resolution data processing method and a higher duty cycle is suggested for maximum methodological efficiency.

The effect of long-term corticosterone treatment on blood cell differentials and function in laboratory and wild-caught amphibian models.

PubMed

Falso, Paul G; Noble, Christopher A; Diaz, Jesus M; Hayes, Tyrone B

2015-02-01

The effect of long-term stress on amphibian immunity is not well understood. We modeled a long-term endocrine stress scenario by elevating plasma corticosterone in two species of amphibians and examined effects on white blood cell differentials and innate immune activity. Plasma corticosterone was elevated in American bullfrogs (Lithobates catesbeianus) by surgically implanting corticosterone capsules and in African clawed frogs (Xenopus laevis) by immersion in corticosterone-treated water. To provide a context for our results within endogenous corticosterone fluctuations, diurnal plasma corticosterone cycles were determined. A daily low of corticosterone was observed in X. laevis at 12:00, while a significant pattern was not observed in L. catesbeianus. Elevated plasma corticosterone levels increased the ratio of peripheral neutrophils to lymphocytes, in both species, and decreased eosinophil concentrations in L. catesbeianus over a long-term period. Whole blood oxidative burst generally correlated with neutrophil concentrations, and thus was increased with corticosterone treatment, significantly in L. catesbeianus. In L. catesbeianus, an endogenous response of eosinophils and lymphocytes to implanted empty (sham) capsules was observed, but this effect was attenuated by corticosterone. Peripheral monocyte and basophil concentrations were not significantly altered by corticosterone treatment in either species. Our results show that long-term stress can alter amphibian immune parameters for extended periods and may play a role in susceptibility to disease. Copyright © 2015 Elsevier Inc. All rights reserved.

Exposure assessment of natural uranium from drinking water.

PubMed

Jakhu, Rajan; Mehra, Rohit; Mittal, H M

2016-12-08

The uranium concentration in the drinking water of the residents of the Jaipur and Ajmer districts of Rajasthan has been measured for exposure assessment. The daily intake of uranium from the drinking water for the residents of the study area is found to vary from 0.4 to 123.9 μg per day. For the average uranium ingestion rate of 35.2 μg per day for a long term exposure period of 60 years, estimations have been made for the retention of uranium in different body organs and its excretion with time using ICRP's biokinetic model of uranium. Radioactive and chemical toxicity of uranium has been reported and discussed in detail in the present manuscript.

Beyond long memory in heart rate variability: An approach based on fractionally integrated autoregressive moving average time series models with conditional heteroscedasticity

NASA Astrophysics Data System (ADS)

Leite, Argentina; Paula Rocha, Ana; Eduarda Silva, Maria

2013-06-01

Heart Rate Variability (HRV) series exhibit long memory and time-varying conditional variance. This work considers the Fractionally Integrated AutoRegressive Moving Average (ARFIMA) models with Generalized AutoRegressive Conditional Heteroscedastic (GARCH) errors. ARFIMA-GARCH models may be used to capture and remove long memory and estimate the conditional volatility in 24 h HRV recordings. The ARFIMA-GARCH approach is applied to fifteen long term HRV series available at Physionet, leading to the discrimination among normal individuals, heart failure patients, and patients with atrial fibrillation.

[Time-series analysis of ambient PM₁₀ pollution on residential mortality in Beijing].

PubMed

Xue, Jiang-li; Wang, Qi; Cai, Yue; Zhou, Mai-geng

2012-05-01

To explore the short-term impact of ambient PM(10) on daily non-accidental death, cardiovascular and respiratory death of residents in Beijing. Mortality data of residents in Beijing during 2006 to 2009 were obtained from public health surveillance and information service center of Chinese Center for Disease Control and Prevention, contemporaneous data of average daily air concentration of PM(10), SO(2), NO(2) were obtained from Beijing Environment Protection Bureau (year 2005 - 2006) and public website of Beijing environmental protection (year 2007 - 2009), respectively, contemporaneous meteorological data were obtained from china meteorological data sharing service system. Generalized addictive model (GAM) of time serial analysis was applied. In additional to the control of confounding factors such as long-term trend, day of the week effect, meteorological factors, lag effect and the effects of other atmospheric pollutants were also analyzed. During year 2006 to 2009, the number of average daily non-accidental death, respiratory disease caused death, cardiovascular and cerebrovascular diseases caused death among Beijing residents were 140.1, 15.0, 65.8, respectively;contemporaneous medians of average daily air concentration of PM(10), SO(2), NO(2) were 123.0, 26.0, 58.0 µg/m(3), respectively;contemporaneous average atmosphere pressure, temperature and relative humidity were 10.1 kPa, 13.5°C and 51.9%, respectively. An exposure-response relationship between exposure to ambient PM(10) and increased daily death number was found as every 10 µg/m(3) increase in daily average concentration of PM(10), there was a 0.1267% (95%CI: 0.0824% - 0.1710%) increase in daily non-accidental death of residents, 0.1365% (95%CI: 0.0010% - 0.2720%) increase in respiratory death and 0.1239% (95%CI: 0.0589% - 0.1889%) increase in cardiovascular death. Ambient PM(10) had greatest influence on daily non-accidental and cardiovascular death of the same day, while its greatest influence on respiratory death occurred 5 days later. The ambient PM(10) pollution increased daily non-accidental, respiratory disease caused, cardiovascular and cerebrovascular diseases caused deaths among residents in Beijing, and lag effect existed as for the effect of ambient PM(10) pollution on respiratory disease caused death.

Effect of 26 Years of Intensively Managed Carya cathayensis Stands on Soil Organic Carbon and Fertility

PubMed Central

Wu, Jiasen; Huang, Jianqin; Liu, Dan; Li, Jianwu; Zhang, Jinchi; Wang, Hailong

2014-01-01

Chinese hickory (Carya cathayensis), a popular nut food tree species, is mainly distributed in southeastern China. A field study was carried out to investigate the effect of long-term intensive management on fertility of soils under a C. cathayensis forest. Results showed that after 26 years' intensive management, the soil organic carbon (SOC) content of the A and B horizons reduced by 19% and 14%, respectively. The reduced components of SOC are mainly the alkyl C and O-alkyl C, whereas the aromatic C and carbonyl C remain unchanged. The reduction of active organic matter could result in degradation of soil fertility. The pH value of soil in the A horizon had dropped by 0.7 units on average. The concentrations of the major nutrients also showed a decreasing trend. On average the concentrations of total nitrogen (N), phosphorus (P), and potassium (K) of tested soils dropped by 21.8%, 7.6%, and 13.6%, respectively, in the A horizon. To sustain the soil fertility and C. cathayensis production, it is recommended that more organic fertilizers (manures) should be used together with chemical fertilizers. Lime should also be applied to reduce soil acidity. PMID:24558339

Effect of 26 years of intensively managed Carya cathayensis stands on soil organic carbon and fertility.

PubMed

Wu, Jiasen; Huang, Jianqin; Liu, Dan; Li, Jianwu; Zhang, Jinchi; Wang, Hailong

2014-01-01

Chinese hickory (Carya cathayensis), a popular nut food tree species, is mainly distributed in southeastern China. A field study was carried out to investigate the effect of long-term intensive management on fertility of soils under a C. cathayensis forest. Results showed that after 26 years' intensive management, the soil organic carbon (SOC) content of the A and B horizons reduced by 19% and 14%, respectively. The reduced components of SOC are mainly the alkyl C and O-alkyl C, whereas the aromatic C and carbonyl C remain unchanged. The reduction of active organic matter could result in degradation of soil fertility. The pH value of soil in the A horizon had dropped by 0.7 units on average. The concentrations of the major nutrients also showed a decreasing trend. On average the concentrations of total nitrogen (N), phosphorus (P), and potassium (K) of tested soils dropped by 21.8%, 7.6%, and 13.6%, respectively, in the A horizon. To sustain the soil fertility and C. cathayensis production, it is recommended that more organic fertilizers (manures) should be used together with chemical fertilizers. Lime should also be applied to reduce soil acidity.

Modelling and Evaluation of Environmental Impact due to Continuous Emissions of the Severonickel Plant (Kola Peninsula)

NASA Astrophysics Data System (ADS)

Mahura, A.; Gonzalez-Aparicio, I.; Nuterman, R.; Baklanov, A.

2012-04-01

In this study, evaluation of potential impact - through concentration, deposition and loadings patterns - on population and environment due to continuous anthropogenic emissions (on example of sulfates) of the Cu-Ni smelters of the Russian North is given. To estimate impact, the Danish Emergency Response Model for Atmosphere (DERMA) was employed to perform long-term simulations of air concentration, time integrated air concentration (TIAC), dry (DD) and wet (WD) deposition patterns resulting from continuous emissions of the Severonickel smelters located on the Kola Peninsula (Murmansk region, Russia). To perform such simulations the 3D meteorological fields (from the European Center for Medium-Range Weather Forecasts, ECMWF) for the year 2000 were used as input. For simplicity, it has been assumed that normalized releases of sulfates from smelters location occurred at a constant rate every day. For each daily release the atmospheric transport, dispersion, dry and wet deposition due to removal processes were estimated during 10 day interval. Output from these long-term simulations is an essential input for evaluation of impact, doses, risks, and short- and long-term consequences, etc. Detailed analyses of simulated concentration and deposition fields allowed evaluating the spatial and temporal variability of resulted patterns on different scales. Temporal variability of both wet and dry deposition as well as their contribution into total deposition have been estimated. On an annual scale, the concentration and deposition patterns were estimated for the most populated cities of the North-West Russia. The modeled annual fields were also integrated into GIS environment as well as layers with population density (from the Center for International Earth Science Information Network, CIESIN) and standard administrative division of the North-West Russia and bordering countries. Furthermore, the estimation of deposited amounts (loadings) of sulfates for selected regions of Russia and border countries has been performed. It has been found that for the "mild emission scenario" (i.e. approx. 31.6 ths. ton), for the Severonickel smelters, the annual average daily dry deposition value is 5.79 ton (with the highest - 10.4 ton - in September, and the lowest - 2.9 ton - in March). The annual average daily wet deposition is 22.7 tons, and a strong month-to-month variability is seen compared with dry deposition. The highest average WD (46.3 ton) is in January, and the lowest - 5.5 ton - in July. There are also differences in amount deposited in total from daily releases. On an annual scale, on average, 32.9% of emitted amount could be deposited at the surface during the considered duration (i.e. 10 days) of atmospheric transport. The highest deposited amount of 57.2% is observed in January and the lowest of 14.3% - in July. Taking into account actual annual (on example of year 2000) emissions of sulfur dioxide as 45.3 ths. ton (Severonickel smelters, city of Monchegorsk), the summary annual time integrated air concentration, dry and wet deposition were re-scaled and these have been estimated for most populated cities (Arkhangelsk, Petrozavodsk, Sankt-Petersburg, Syktyvkar, Pskov, and Vologda) of the North-West Russia. It was found that among these cities, the TIAC is the highest - 86 μg•h/m3 - for Arkhangelsk and the lowest - 4 μg•h/m3 - for Pskov. Both dry and wet depositions were also the highest for Arkhangelsk - 0.5 and 2.2 mg/m2, respectively. Detailed analysis also showed that for regions surrounding the Kola Peninsula, on average (maximum), the total (dry plus wet) deposition was 0.6 (3.0), 1.8 (5.1), and 28.3 (122) mg/m2 for the territories of the Arkhangelsk, Karelia, and Murmansk regions of Russia. For border regions with Scandinavian countries, on average (maximum), the total deposition was 2.2 (6.7) mg/m2 in Finnmark (Norway); 0.2 (0.4) in Norrbotten and 0.03 (0.1) mg/m2 in Vsterbotten counties (Sweden); 0.6 (1.2) in Eastern Finland, 2.2 (7.2) in Lapland, and 1.4 (2.9) mg/m2 in Oulu provinces of Finland. For urban population living in the central and northern territories of the Kola Peninsula the yearly loading due to deposition of sulfates could be more than 40 kg/person. For bordering territories with the Murmansk region such loadings are less than 5 kg/person for the Eastern Finland, Karelia, and Arkhangelsk regions; and up to 15 kg/person - for the Northern Norway.

Long-term efficacy of polyethylene glycol 3350 for the treatment of chronic constipation in children with and without encopresis.

PubMed

Pashankar, Dinesh S; Bishop, Warren P; Loening-Baucke, Vera

2003-01-01

Seventy-four children (43 with chronic constipation, 31 with constipation and encopresis) treated with polyethylene glycol 3350 (PEG) for longer than 3 months were studied to assess long-term efficacy. The mean duration of PEG therapy was 8.4 months (range, 3-30). Weekly stool frequency, stool consistency, and symptoms associated with constipation improved significantly with PEG therapy in all 74 patients. In 31 children with encopresis, soiling ceased completely in 16 patients and frequency of soiling decreased significantly in all others. The average effective long-term dose of PEG was 0.7 g/kg/day. Long-term PEG therapy is effective for the treatment of chronic constipation with and without encopresis in children.

Radiologically Guided Placement of Mushroom-retained Gastrostomy Catheters: Long-term Outcomes of Use in 300 Patients at a Single Center.

PubMed

Ahmed, Osman; Jilani, Danial; Sheth, Sujay; Giger, Maryellen; Funaki, Brian

2015-08-01

To assess long-term outcomes including risk of complications and nutritional benefits of mushroom-retained (pull-type) gastrostomy catheters placed in patients by interventional radiologists. All patients who received pull-type gastrostomy tubes between 2010 and 2013 were retrospectively reviewed, including 142 men (average weight, 169.6 lb [76.32 kg]; mean age, 65.2 years; range, 22-92 years) and 158 women (average weight, 150.4 lb [67.68 kg]; mean age, 65.2 years; range, 18-98 years). Indications for placement were cerebrovascular accident (n = 80), failure to thrive (n = 71), other central nervous system disorder (n = 51), head and neck cancer (n = 47), and other malignancy (n = 51). Complications were recorded per Society of Interventional Radiology practice guidelines. Patient weight was documented at specific follow-up intervals. Statistical analysis was performed by using the Student t test and one-way analysis of variance for the effects of sex and indication for placement, respectively, on average weight change. The technical success rate was 98.4% (300 of 305 patients). Major and minor complications occurred at a rate of 3.7% (n = 11) and 13% (n = 39), respectively. Follow-up weight during the early (≤45 days), intermediate (≤180 days), and long-term (>180 days) periods was available for 71% (n = 214), 36% (n = 108), and 15% (n = 44) of the 300 patients, respectively. Weight gain occurred in 77% (160 of 214), 60% (65 of 108), and 73% (32 of 44) of the patients, respectively. Patients who gained weight gained 6.7, 10.6, and 16.3 lb (3.02, 4.77, and 7.34 kg) during each follow-up period, respectively. Average weight gain at follow-up in all patients was 4.2, 0.6, and 5.4 lb (1.89, 0.27, and 2.43 kg), respectively. No significant differences in average weight change were seen among groups when they were classified according to sex or indication for placement. Placement of mushroom-retained gastrostomy catheters is a viable long-term treatment option for enteral nutrition, with complication rates similar to those reported for other gastrostomy techniques. Improvement in nutrition status measured as weight gain was seen in most patients in both early and long-term periods. (©) RSNA, 2015.

Influence of long-term consumption of bitter apricot seeds on risk factors for cardiovascular diseases.

PubMed

Kopčeková, Jana; Kolesárová, Anna; Kováčik, Anton; Kováčiková, Eva; Gažarová, Martina; Chlebo, Peter; Valuch, Jozef; Kolesárová, Adriana

2018-05-04

The present study was designed to reveal whether long-term consumption of bitter apricot seeds causes changes in lipid profile and other risk factors for cardiovascular diseases. The study group consisted of 12 healthy adult volunteers (5 females and 7 males). The average age of women was 41.60 ± 11.28 years and the average age of men was 36.71 ± 13.70 years. Volunteers consumed 60 mg kg -1 of body weight of bitter apricot seeds divided into 8-12 doses daily for 12 weeks. Volunteers were recruited from the general population of Slovak Republic. After 12 weeks, mean body weight of the participants increased from 77.34 to 78.22 kg (P > 0.05). The average total cholesterol levels decreased from 4.86 mmol L -1 at the beginning of the study to 4.44 mmol L -1 at the end of the study (P < 0.05). We did not observe any significant increase in high-density cholesterol (from 1.55 to 1.60 mmol L -1 ). The average low-density cholesterol levels decreased from 2.93 mmol L -1 at the beginning of the study to 2.31 mmol L -1 at the end of the study (P < 0.001). Concentration of triglycerides increased significantly over the 12-week intervention period from 0.84 to 1.17 mmol L -1 . After the intervention, the high-sensitivity C-reactive protein level decreased from 1.92 to 1.23 mg L -1 , but results were non-significant (P > 0.05). Creatine kinase serum levels increased from 2.31 to 2.77 mg L -1 (P > 0.05) over the 12-week intervention period. The results suggest that regular intake of bitter apricot seeds may be considered potentially useful for prevention of cardiovascular diseases.

Increased mitochondrial energy efficiency in skeletal muscle after long-term fasting: its relevance to animal performance.

PubMed

Bourguignon, Aurore; Rameau, Anaïs; Toullec, Gaëlle; Romestaing, Caroline; Roussel, Damien

2017-07-01

In the final stage of fasting, skeletal muscle mass and protein content drastically decrease when the maintenance of efficient locomotor activity becomes crucial for animals to reactivate feeding behaviour and survive a very long period of starvation. As mitochondrial metabolism represents the main physiological link between the endogenous energy store and animal performance, the aim of this study was to determine how a very long, natural period of fasting affected skeletal muscle mitochondrial bioenergetics in king penguin ( Aptenodytes patagonicus ) chicks. Rates of mitochondrial oxidative phosphorylation were measured in pectoralis permeabilized fibres and isolated mitochondria. Mitochondrial ATP synthesis efficiency and the activities of respiratory chain complexes were measured in mitochondria isolated from pectoralis muscle. Results from long-term (4-5 months) naturally fasted chicks were compared with those from short-term (10 day) fasted birds. The respiratory activities of muscle fibres and isolated mitochondria were reduced by 60% and 45%, respectively, on average in long-term fasted chicks compared with short-term fasted birds. Oxidative capacity and mitochondrial content of pectoralis muscle were lowered by long-term fasting. Bioenergetic analysis of pectoralis muscle also revealed that mitochondria were, on average, 25% more energy efficient in the final stage of fasting (4-5 months) than after 10 days of fasting (short-term fasted birds). These results suggest that the strong reduction in respiratory capacity of pectoralis muscle was partly alleviated by increased mitochondrial ATP synthesis efficiency. Such oxidative phosphorylation optimization can impact animal performance, e.g. the metabolic cost of locomotion or the foraging efficiency. © 2017. Published by The Company of Biologists Ltd.

Long Term Psychological and Physical Effects of the POW Experience: A Review of the Literature

DTIC Science & Technology

1974-01-01

depression, rage, and psyhosotnatic conversions such as ulcer , migraine, and colitis . These were followed by an incubation of anxiety symptoms, also called...of cause and effect. Even when not based only on a small number of patients in psychiatric treatment, most papers on concentration camp survivors...survivors of the horrendous trauma of concentration camps. Al- though overall data on the incidence and prevalence of long-term psychiatric

Effective production planning for purchased part under long lead time and uncertain demand: MRP Vs demand-driven MRP

NASA Astrophysics Data System (ADS)

Shofa, M. J.; Moeis, A. O.; Restiana, N.

2018-04-01

MRP as a production planning system is appropriate for the deterministic environment. Unfortunately, most production systems such as customer demands are stochastic, so that MRP is inappropriate at the time. Demand-Driven MRP (DDMRP) is new approach for production planning system dealing with demand uncertainty. The objective of this paper is to compare the MRP and DDMRP for purchased part under long lead time and uncertain demand in terms of average inventory levels. The evaluation is conducted through a discrete event simulation with the long lead time and uncertain demand scenarios. The next step is evaluating the performance of DDMRP by comparing the inventory level of DDMRP with MRP. As result, DDMRP is more effective production planning than MRP in terms of average inventory levels.

Support, shape and number of replicate samples for tree foliage analysis.

PubMed

Luyssaert, Sebastiaan; Mertens, Jan; Raitio, Hannu

2003-06-01

Many fundamental features of a sampling program are determined by the heterogeneity of the object under study and the settings for the error (alpha), the power (beta), the effect size (ES), the number of replicate samples, and sample support, which is a feature that is often overlooked. The number of replicates, alpha, beta, ES, and sample support are interconnected. The effect of the sample support and its shape on the required number of replicate samples was investigated by means of a resampling method. The method was applied to a simulated distribution of Cd in the crown of a Salix fragilis L. tree. Increasing the dimensions of the sample support results in a decrease in the variance of the element concentration under study. Analysis of the variance is often the foundation of statistical tests, therefore, valid statistical testing requires the use of a fixed sample support during the experiment. This requirement might be difficult to meet in time-series analyses and long-term monitoring programs. Sample supports have their largest dimension in the direction with the largest heterogeneity, i.e. the direction representing the crown height, and this will give more accurate results than supports with other shapes. Taking the relationships between the sample support and the variance of the element concentrations in tree crowns into account provides guidelines for sampling efficiency in terms of precision and costs. In terms of time, the optimal support to test whether the average Cd concentration of the crown exceeds a threshold value is 0.405 m3 (alpha = 0.05, beta = 0.20, ES = 1.0 mg kg(-1) dry mass). The average weight of this support is 23 g dry mass, and 11 replicate samples need to be taken. It should be noted that in this case the optimal support applies to Cd under conditions similar to those of the simulation, but not necessarily all the examinations for this tree species, element, and hypothesis test.

Deciphering the Long-Term Trend of Atlantic Basin Intense Hurricanes: More Active Versus Less Active During the Present Epoch

NASA Technical Reports Server (NTRS)

Wilson, Robert M.

1998-01-01

During the interval of 1944-1997, 120 intense hurricanes (i.e., those of category 3 or higher on the Saffir-Simpson hurricane damage potential scale) were observed in the Atlantic basin, having an annual frequency of 0-7 events per year, being more active prior to the mid 1960's than thereafter (hence a possible two-state division: more active versus less active), and being preferentially lower during El Nino years as compared to non-El Nino years. Because decadal averages of the frequency of intense hurricanes closely resemble those of average temperature anomalies for northern hemispheric and global standards and of the average temperature at the Armagh Observatory (Northern Ireland), a proxy for climatic change, it is inferred that the long-term trends of the annual frequency of intense hurricanes and temperature may be statistically related. Indeed, on the basis of 4- and 10-yr moving averages, one finds that there exists strong linear associations between the annual frequency of intense hurricanes in the Atlantic basin and temperature (specially, when temperature slightly leads). Because the long-term leading trends of temperature are now decidedly upward, beginning about the mid 1980's, it is inferred that the long-term consequential trends of the annual frequency of intense hurricanes should now also be upward, having begun near 1990, suggesting that a return to the more active state probably has already occurred. However, because of the anomalous El Nino activity of the early to mid 1990's, the switch from the less active to the more active state essentially went unnoticed (a marked increase in the number of intense hurricanes was not observed until the 1995 and 1996 hurricane seasons, following the end of the anomalous El Nino activity). Presuming that a return to the more active state has, indeed, occurred, one expects the number of seasonal intense hurricanes during the present epoch (continuing through about 2012) to usually be higher than average (i.e., greater than or equal to 2), except during El Nino-related seasons when the number usually will be less than average.

Mass balance, meteorology, area altitude distribution, glacier-surface altitude, ice motion, terminus position, and runoff at Gulkana Glacier, Alaska, 1996 balance year

USGS Publications Warehouse

March, Rod S.

2003-01-01

The 1996 measured winter snow, maximum winter snow, net, and annual balances in the Gulkana Glacier Basin were evaluated on the basis of meteorological, hydrological, and glaciological data. Averaged over the glacier, the measured winter snow balance was 0.87 meter on April 18, 1996, 1.1 standard deviation below the long-term average; the maximum winter snow balance, 1.06 meters, was reached on May 28, 1996; and the net balance (from August 30, 1995, to August 24, 1996) was -0.53 meter, 0.53 standard deviation below the long-term average. The annual balance (October 1, 1995, to September 30, 1996) was -0.37 meter. Area-averaged balances were reported using both the 1967 and 1993 area altitude distributions (the numbers previously given in this abstract use the 1993 area altitude distribution). Net balance was about 25 percent less negative using the 1993 area altitude distribution than the 1967 distribution. Annual average air temperature was 0.9 degree Celsius warmer than that recorded with the analog sensor used since 1966. Total precipitation catch for the year was 0.78 meter, 0.8 standard deviations below normal. The annual average wind speed was 3.5 meters per second in the first year of measuring wind speed. Annual runoff averaged 1.50 meters over the basin, 1.0 standard deviation below the long-term average. Glacier-surface altitude and ice-motion changes measured at three index sites document seasonal ice-speed and glacier-thickness changes. Both showed a continuation of a slowing and thinning trend present in the 1990s. The glacier terminus and lower ablation area were defined for 1996 with a handheld Global Positioning System survey of 126 locations spread out over about 4 kilometers on the lower glacier margin. From 1949 to 1996, the terminus retreated about 1,650 meters for an average retreat rate of 35 meters per year.

Regional grassland productivity responses to precipitation during multiyear above- and below-average rainfall periods.

PubMed

Petrie, Matthew D; Peters, Debra P C; Yao, Jin; Blair, John M; Burruss, Nathan D; Collins, Scott L; Derner, Justin D; Gherardi, Laureano A; Hendrickson, John R; Sala, Osvaldo E; Starks, Patrick J; Steiner, Jean L

2018-05-01

There is considerable uncertainty in the magnitude and direction of changes in precipitation associated with climate change, and ecosystem responses are also uncertain. Multiyear periods of above- and below-average rainfall may foretell consequences of changes in rainfall regime. We compiled long-term aboveground net primary productivity (ANPP) and precipitation (PPT) data for eight North American grasslands, and quantified relationships between ANPP and PPT at each site, and in 1-3 year periods of above- and below-average rainfall for mesic, semiarid cool, and semiarid warm grassland types. Our objective was to improve understanding of ANPP dynamics associated with changing climatic conditions by contrasting PPT-ANPP relationships in above- and below-average PPT years to those that occurred during sequences of multiple above- and below-average years. We found differences in PPT-ANPP relationships in above- and below-average years compared to long-term site averages, and variation in ANPP not explained by PPT totals that likely are attributed to legacy effects. The correlation between ANPP and current- and prior-year conditions changed from year to year throughout multiyear periods, with some legacy effects declining, and new responses emerging. Thus, ANPP in a given year was influenced by sequences of conditions that varied across grassland types and climates. Most importantly, the influence of prior-year ANPP often increased with the length of multiyear periods, whereas the influence of the amount of current-year PPT declined. Although the mechanisms by which a directional change in the frequency of above- and below-average years imposes a persistent change in grassland ANPP require further investigation, our results emphasize the importance of legacy effects on productivity for sequences of above- vs. below-average years, and illustrate the utility of long-term data to examine these patterns. © 2018 John Wiley & Sons Ltd.

Normal and anomalous diffusion in fluctuations of dust concentration nearby emission source

NASA Astrophysics Data System (ADS)

Szczurek, Andrzej; Maciejewska, Monika; Wyłomańska, Agnieszka; Sikora, Grzegorz; Balcerek, Michał; Teuerle, Marek

2018-02-01

Particulate matter (PM) is an important component of air. Nowadays, major attention is payed to fine dust. It has considerable environmental impact, including adverse effect on human health. One of important issues regarding PM is the temporal variation of its concentration. The variation contains information about factors influencing this quantity in time. The work focuses on the character of PM concentration dynamics indoors, in the vicinity of emission source. The objective was to recognize between the homogeneous or heterogeneous dynamics. The goal was achieved by detecting normal and anomalous diffusion in fluctuations of PM concentration. For this purpose we used anomalous diffusion exponent, β which was derived from Mean Square Displacement (MSD) analysis. The information about PM concentration dynamics may be used to design sampling strategy, which serves to attain representative information about PM behavior in time. The data analyzed in this work was collected from single-point PM concentration monitoring in the vicinity of seven emission sources in industrial environment. In majority of cases we observed heterogeneous character of PM concentration dynamics. It confirms the complexity of interactions between the emission sources and indoor environment. This result also votes against simplistic approach to PM concentration measurement indoors, namely their occasional character, short measurement periods and long term averaging.

Fecal 20-oxo-pregnane concentrations in free-ranging African elephants (Loxodonta africana) treated with porcine zona pellucida vaccine.

PubMed

Ahlers, M J; Ganswindt, A; Münscher, S; Bertschinger, H J

2012-07-01

Because of overpopulation of African elephants in South Africa and the consequent threat to biodiversity, the need for a method of population control has become evident. In this regard, the potential use of the porcine zona pellucida (pZP) vaccine as an effective means for population control is explored. While potential effects of pZP treatment on social behavior of African elephants have been investigated, no examination of the influence of pZP vaccination on the endocrine correlates in treated females has been undertaken. In this study, ovarian activity of free-ranging, pZP-treated African elephant females was monitored noninvasively for 1 yr at Thornybush Private Nature Reserve, South Africa, by measuring fecal 5α-pregnan-3β-ol-20-on concentrations via enzyme immunoassay. A total of 719 fecal samples from 19 individuals were collected over the study period, averaging 38 samples collected per individual (minimum, maximum: 16, 52). Simultaneously, behavioral observations were made to record the occurrence of estrous behavior for comparison. Each elephant under study showed 5α-pregnan-3β-ol-20-on concentrations rising above baseline at some period during the study indicating luteal activity. Average 5α-pregnan-3β-ol-20-on concentrations were 1.61 ± 0.46 μg/g (mean ± SD). Within sampled females, 42.9% exhibited estrous cycles within the range reported for captive African elephants, 14.3% had irregular cycles, and 42.9% did not appear to be cycling. Average estrous cycle duration was 14.72 ± 0.85 wk. Estrous behavior coincided with the onset of the luteal phase and a subsequent rise in 5α-pregnan-3β-ol-20-on concentrations. Average 5α-pregnan-3β-ol-20-on levels positively correlated with rainfall. No association between average individual 5α-pregnan-3β-ol-20-on concentrations or cyclicity status with age or parity were detected. Earlier determination of efficacy was established via fecal hormone analysis with no pregnancies determined 22 mo post-treatment and onward. Results indicate the presence of ovarian activity amongst pZP-treated female African elephants in 2 yr after initial immunization. Further study should now be aimed toward investigating the long-term effects of pZP vaccination on the reproductive function of female African elephants. Copyright © 2012 Elsevier Inc. All rights reserved.

Continuous real-time water-quality monitoring and regression analysis to compute constituent concentrations and loads in the North Fork Ninnescah River upstream from Cheney Reservoir, south-central Kansas, 1999–2012

USGS Publications Warehouse

Stone, Mandy L.; Graham, Jennifer L.; Gatotho, Jackline W.

2013-01-01

Cheney Reservoir, located in south-central Kansas, is the primary water supply for the city of Wichita. The U.S. Geological Survey has operated a continuous real-time water-quality monitoring station since 1998 on the North Fork Ninnescah River, the main source of inflow to Cheney Reservoir. Continuously measured water-quality physical properties include streamflow, specific conductance, pH, water temperature, dissolved oxygen, and turbidity. Discrete water-quality samples were collected during 1999 through 2009 and analyzed for sediment, nutrients, bacteria, and other water-quality constituents. Regression models were developed to establish relations between discretely sampled constituent concentrations and continuously measured physical properties to compute concentrations of those constituents of interest that are not easily measured in real time because of limitations in sensor technology and fiscal constraints. Regression models were published in 2006 that were based on data collected during 1997 through 2003. This report updates those models using discrete and continuous data collected during January 1999 through December 2009. Models also were developed for four new constituents, including additional nutrient species and indicator bacteria. In addition, a conversion factor of 0.68 was established to convert the Yellow Springs Instruments (YSI) model 6026 turbidity sensor measurements to the newer YSI model 6136 sensor at the North Ninnescah River upstream from Cheney Reservoir site. Newly developed models and 14 years of hourly continuously measured data were used to calculate selected constituent concentrations and loads during January 1999 through December 2012. The water-quality information in this report is important to the city of Wichita because it allows the concentrations of many potential pollutants of interest to Cheney Reservoir, including nutrients and sediment, to be estimated in real time and characterized over conditions and time scales that would not be possible otherwise. In general, model forms and the amount of variance explained by the models was similar between the original and updated models. The amount of variance explained by the updated models changed by 10 percent or less relative to the original models. Total nitrogen, nitrate, organic nitrogen, E. coli bacteria, and total organic carbon models were newly developed for this report. Additional data collection over a wider range of hydrological conditions facilitated the development of these models. The nitrate model is particularly important because it allows for comparison to Cheney Reservoir Task Force goals. Mean hourly computed total suspended solids concentration during 1999 through 2012 was 54 milligrams per liter (mg/L). The total suspended solids load during 1999 through 2012 was 174,031 tons. On an average annual basis, the Cheney Reservoir Task Force runoff (550 mg/L) and long-term (100 mg/L) total suspended solids goals were never exceeded, but the base flow goal was exceeded every year during 1999 through 2012. Mean hourly computed nitrate concentration was 1.08 mg/L during 1999 through 2012. The total nitrate load during 1999 through 2012 was 1,361 tons. On an annual average basis, the Cheney Reservoir Task Force runoff (6.60 mg/L) nitrate goal was never exceeded, the long-term goal (1.20 mg/L) was exceeded only in 2012, and the base flow goal of 0.25 mg/L was exceeded every year. Mean nitrate concentrations that were higher during base flow, rather than during runoff conditions, suggest that groundwater sources are the main contributors of nitrate to the North Fork Ninnescah River above Cheney Reservoir. Mean hourly computed phosphorus concentration was 0.14 mg/L during 1999 through 2012. The total phosphorus load during 1999 through 2012 was 328 tons. On an average annual basis, the Cheney Reservoir Task Force runoff goal of 0.40 mg/L for total phosphorus was exceeded in 2002, the year with the largest yearly mean turbidity, and the long-term goal (0.10 mg/L) was exceeded in every year except 2011 and 2012, the years with the smallest mean streamflows. The total phosphorus base flow goal of 0.05 mg/L was exceeded every year. Given that base flow goals for total suspended solids, nitrate, and total phosphorus were exceeded every year despite hydrologic conditions, the established base flow goals are either unattainable or substantially more best management practices will need to be implemented to attain them. On an annual average basis, no discernible patterns were evident in total suspended sediment, nitrate, and total phosphorus concentrations or loads over time, in large part because of hydrologic variability. However, more rigorous statistical analyses are required to evaluate temporal trends. A more rigorous analysis of temporal trends will allow evaluation of watershed investments in best management practices.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhou, Chen; Zelinka, Mark D.; Dessler, Andrew E.

The analyses of Coupled Model Intercomparison Project phase 5 simulations suggest that climate models with more positive cloud feedback in response to interannual climate fluctuations also have more positive cloud feedback in response to long-term global warming. Ensemble mean vertical profiles of cloud change in response to interannual and long-term surface warming are similar, and the ensemble mean cloud feedback is positive on both timescales. However, the average long-term cloud feedback is smaller than the interannual cloud feedback, likely due to differences in surface warming pattern on the two timescales. Low cloud cover (LCC) change in response to interannual andmore » long-term global surface warming is found to be well correlated across models and explains over half of the covariance between interannual and long-term cloud feedback. In conclusion, the intermodel correlation of LCC across timescales likely results from model-specific sensitivities of LCC to sea surface warming.« less

Compilation of water resources development and hydrologic data of Saipan, Mariana Islands

USGS Publications Warehouse

Van der Brug, Otto

1985-01-01

Saipan is the largest island of the Northern Mariana Islands, a chain of 14 islands north of Guam. Saipan comprises one third of the land area of the islands. No long-term rainfall record is available at any location, but some rainfall records are for periods up to 16 years, some of which began in 1901. Average annual rainfall for the island is 81 inches, with the southern end receiving about 10 inches less annually than the rest of the island. The amount of rainfall which runs off in northeast Saipan ranges from 23 to 64 percent and averages about 40 percent. Runoff on the rest of the island is from springs or occurs only during heavy rainfall. Surface-water development appears impractical. Ground water is the main source of water for the island and production was almost 4 million gallons per day in 1982. However, chloride concentration in ground water exceeds 1,000 milligrams per liter in many locations. The average chloride concentration of the domestic water stays near the maximum permissible level (600 milligrams per liter). This report summarizes the history of the water-resources development and presents all available hydrologic data, including rainfall records since 1901, streamflow records since 1968, and drilling logs, pumping tests, chemical analyses, and production figures from 180 testholes and wells drilled on Saipan. (USGS)

Decadal trend of black carbon and refractory carbonaceous aerosol in the western rim of the North Pacific Ocean: atmospheric concentration and the retrieved record of deposition flux

NASA Astrophysics Data System (ADS)

Kaneyasu, Naoki; Yamaguchi, Takashi; Noguchi, Izumi; Akiyama, Masayuki; Matsumoto, Kiyoshi

2013-04-01

The long-term trend of light absorbing carbonaceous aerosols (or black carbon: BC) or refractory carbonaceous aerosol (or elemental carbon: EC) concentration is reported at European background sites such as Mace Head, and that of aerosol absorption coefficient are monitored in many GAW sites. On the contrary, such long-term data are relatively scarce at around the western part of the North Pacific Ocean. Thus, to understand the long-term variation of in the area, BC in fine aerosol fraction has been measured at Chichi-jima Islands, Japan. Chichi-jima Island is located 1000 km south of the Japanese mainland, and 1800 km west of the coast line of the Asian continent. BC has been measured with an Aethalometer (Magee, AE-16 and AE-30) since December, 1998 with 1 hr time resolution. Mass flowmeter embedded inside the Aethalometer is calibrated with a rotational dry gas-meter once a year. Monthly averaged BC concentration shows an obvious seasonal variation, i.e. high concentration during late autumn-winter-spring period resulting from the transport from East Asia, with maximum daily concentration above 500 ng m-3. In summer, daily concentration was usually less than 20 ng m-3, due to the clean background airmass originating from the North Pacific Anticyclone. Decadal trend of the annual averaged BC concentration showed a increasing trend from 2000 to 2007 and started to decrease after 2008, which roughly coincides with the reported emission trend of SO2 in China (Lu et al., 2010). In addition, total (i.e., wet + dry) deposition record of refractory carbon at two sites in the northern Japan (Rishiri Island: a remote island site, and Sapporo City: an urban site) are retrieved. At these sites, the local government have been measuring the chemical components in precipitation water collected by deposition gauges. In the deposition gauge, a membrane filter made of cellulose-acetate is fixed at the bottom of the funnel to remove water-insoluble particles from the precipitated water. Those "used" membrane filters have been archived for almost two decades at Sapporo without interruption, and for 13 years at Rishiri Island intermittently. We developed a procedure to analyse particulate refractory carbon retained on the membrane filter. The analysis was conducted by thermal-optical transmittance (TOT) method with a Sunset Model-4 carbon analyser (IMPROVE protocol. In this study, we call the resultant analytical quantity as TOT-EC(I). In Sapporo, the annual total deposition of TOT-EC(I) in 2011 (80 mg m-2yr-1) decreased greatly from that in 2001 (208 mg m-2 yr-1) probably due to the strict emission control regulation for the exhaust of diesel powered vehicles that took effect in the 2000s in Japan. In Rishi Island, total deposition in 2011 (47 mg m-2 yr-1) also decreased from that of 2001(141 mg m-2 yr-1). However, the monthly variation of the total deposition in 2001 had pronounced springtime increase while that in 2011 is not obvious. Thus, there is a possibility that the data in 2001 at Rishiri Island were affected by the smoke from Siberian forest fire which becomes active typically during the spring to summer season. Reference Lu, Z. et al., ACP. 10, 6311-6331 (2010).

Effect of CoCl(2) treatment on major and trace elements metabolism and protein concentration in mice.

PubMed

Zaksas, Nataliya; Gluhcheva, Yordanka; Sedykh, Sergey; Madzharova, Maria; Atanassova, Nina; Nevinsky, Georgy

2013-01-01

Cobalt (Co) is a transition metal and an essential trace element, required for vitamin B(12) biosynthesis, enzyme activation and other biological processes, but toxic in high concentrations. There is lack of data for the effect of long-term Co(II) treatment on the concentrations of other trace elements. We estimate the influence of cobalt chloride (CoCl(2)) on the relative content of different metals in mouse plasma using two-jet arc plasmatron atomic emission and on the total protein content. On average, the content of different elements in the plasma of 2-month-old balb/c mice (control group) decreased in the order: Ca>Mg>Si>Fe>Zn>Cu≥Al≥B. The treatment of mice for 60 days with CoCl(2) (daily dose 125 mg/kg) did not appreciably change the relative content of Ca, Cu, and Zn, while a 2.4-fold statistically significant decrease in the content of B and significant increase in the content of Mg (1.4-fold), Al and Fe (2.0-fold) and Si (3.2-fold) was found. A detectable amount of Mo was observed only for two control mice, while the plasma of 9 out of 16 mice of the treated group contained this metal. The administration of Co made its concentration detectable in the plasma of all mice of the treated group, but the relative content varied significantly. The treatment led to a 2.2-fold decrease in the concentration of the total plasma protein. Chronic exposure to CoCl(2) affects homeostasis as well as the concentrations and metabolism of other essential elements, probably due to competition of Co ions for similar binding sites within cells, altered signal transduction and protein biosynthesis. Long-term treatment also leads to significant weight changes and reduces the total protein concentration. The data may be useful for an understanding of Co toxicity, its effect on the concentration of other metal ions and different physiological processes. Copyright © 2012 Elsevier GmbH. All rights reserved.

Using spatial-stream-network models and long-term data to understand and predict dynamics of faecal contamination in a mixed land-use catchment.

PubMed

Neill, Aaron James; Tetzlaff, Doerthe; Strachan, Norval James Colin; Hough, Rupert Lloyd; Avery, Lisa Marie; Watson, Helen; Soulsby, Chris

2018-01-15

An 11year dataset of concentrations of E. coli at 10 spatially-distributed sites in a mixed land-use catchment in NE Scotland (52km 2 ) revealed that concentrations were not clearly associated with flow or season. The lack of a clear flow-concentration relationship may have been due to greater water fluxes from less-contaminated headwaters during high flows diluting downstream concentrations, the importance of persistent point sources of E. coli both anthropogenic and agricultural, and possibly the temporal resolution of the dataset. Point sources and year-round grazing of livestock probably obscured clear seasonality in concentrations. Multiple linear regression models identified potential for contamination by anthropogenic point sources as a significant predictor of long-term spatial patterns of low, average and high concentrations of E. coli. Neither arable nor pasture land was significant, even when accounting for hydrological connectivity with a topographic-index method. However, this may have reflected coarse-scale land-cover data inadequately representing "point sources" of agricultural contamination (e.g. direct defecation of livestock into the stream) and temporal changes in availability of E. coli from diffuse sources. Spatial-stream-network models (SSNMs) were applied in a novel context, and had value in making more robust catchment-scale predictions of concentrations of E. coli with estimates of uncertainty, and in enabling identification of potential "hot spots" of faecal contamination. Successfully managing faecal contamination of surface waters is vital for safeguarding public health. Our finding that concentrations of E. coli could not clearly be associated with flow or season may suggest that management strategies should not necessarily target only high flow events or summer when faecal contamination risk is often assumed to be greatest. Furthermore, we identified SSNMs as valuable tools for identifying possible "hot spots" of contamination which could be targeted for management, and for highlighting areas where additional monitoring could help better constrain predictions relating to faecal contamination. Copyright © 2017 Elsevier B.V. All rights reserved.

Short- and long-term effects of carbohydrate limitation on sugar and organic acid accumulation during mandarin fruit growth.

PubMed

Antoine, Sandrine; Pailly, Olivier; Gibon, Yves; Luro, François; Santini, Jérémie; Giannettini, Jean; Berti, Liliane

2016-08-01

The physiological roles of organic acids in fruit cells are not fully understood, especially in citrus, whereas the decline in titratable acidity during ripening shown by many citrus fruits is due to the utilization of citric acid. We induced carbohydrate depletion by removing source leaves at two key periods in mandarin development (early and full citric acid accumulation). Then, we assessed the resulting changes in the short term (within 48 h) and long term (several weeks until ripening). Control mature fruits were characterized by elevated fresh weight, large diameters and high quantities of malic acid, citric acid and sucrose. At the same stage, fruits subjected to early or late defoliation had higher glucose, fructose, citric acid concentrations and lower sucrose concentrations. They differed only in their malic acid concentrations, which were higher in early defoliation fruits and similar in late defoliation fruits when compared to control fruits. Finally, fruits subjected to late defoliation were characterized by high proline and γ-aminobutyric acid concentrations, and low fructose and glucose concentrations. We have shown that short- and long-term carbohydrate limitation modifies sugar and organic acid metabolism during mandarin fruit growth. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

Long-term interactive effects of N addition with P and K availability on N status of Sphagnum.

PubMed

Chiwa, Masaaki; Sheppard, Lucy J; Leith, Ian D; Leeson, Sarah R; Tang, Y Sim; Neil Cape, J

2018-06-01

Little information exists concerning the long-term interactive effect of nitrogen (N) addition with phosphorus (P) and potassium (K) on Sphagnum N status. This study was conducted as part of a long-term N manipulation on Whim bog in south Scotland to evaluate the long-term alleviation effects of phosphorus (P) and potassium (K) on N saturation of Sphagnum (S. capillifolium). On this ombrotrophic peatland, where ambient deposition was 8 kg N ha -1 yr -1 , 56 kg N ha -1 yr -1 of either ammonium (NH 4 + , N red ) or nitrate (NO 3 - , N ox ) with and without P and K, were added over 11 years. Nutrient concentrations of Sphagnum stem and capitulum, and pore water quality of the Sphagnum layer were assessed. The N-saturated Sphagnum caused by long-term (11 years) and high doses (56 kg N ha -1 yr -1 ) of reduced N was not completely ameliorated by P and K addition; N concentrations in Sphagnum capitula for N red 56 PK were comparable with those for N red 56, although N concentrations in Sphagnum stems for N red 56 PK were lower than those for N red 56. While dissolved inorganic nitrogen (DIN) concentrations in pore water for N red 56 PK were not different from N red 56, they were lower for N ox 56 PK than for N ox 56 whose stage of N saturation had not advanced compared to N red 56. These results indicate that increasing P and K availability has only a limited amelioration effect on the N assimilation of Sphagnum at an advanced stage of N saturation. This study concluded that over the long-term P and K additions will not offset the N saturation of Sphagnum. Copyright © 2018 Elsevier Ltd. All rights reserved.

Decadal Trends of Atlantic Basin Tropical Cyclones (1950-1999)

NASA Technical Reports Server (NTRS)

Wilson, Robert M.

2001-01-01

Ten-year moving averages of the seasonal rates for 'named storms,' tropical storms, hurricanes, and major (or intense) hurricanes in the Atlantic basin suggest that the present epoch is one of enhanced activity, marked by seasonal rates typically equal to or above respective long-term median rates. As an example, the 10-year moving average of the seasonal rates for named storms is now higher than for any previous year over the past 50 years, measuring 10.65 in 1994, or 2.65 units higher than its median rate of 8. Also, the 10-year moving average for tropical storms has more than doubled, from 2.15 in 1955 to 4.60 in 1992, with 16 of the past 20 years having a seasonal rate of three or more (the median rate). For hurricanes and major hurricanes, their respective 10-year moving averages turned upward, rising above long-term median rates (5.5 and 2, respectively) in 1992, a response to the abrupt increase in seasonal rates that occurred in 1995. Taken together, the outlook for future hurricane seasons is for all categories of Atlantic basin tropical cyclones to have seasonal rates at levels equal to or above long-term median rates, especially during non-El Nino-related seasons. Only during El Nino-related seasons does it appear likely that seasonal rates might be slightly diminished.

Trends in polycyclic aromatic hydrocarbon concentrations in the great lakes atmosphere.

PubMed

Sun, Ping; Blanchard, Pierrette; Brice, Kenneth A; Hites, Ronald A

2006-10-15

Atmospheric polycyclic aromatic hydrocarbon (PAHs) concentrations were measured in both the vapor and particle phases at seven sites near the Great Lakes as a part of the Integrated Atmospheric Deposition Network. Lower molecular weight PAHs, including fluorene, phenanthrene, fluoranthrene, and pyrene, were dominant in the vapor phase, and higher molecular weight PAHs, including chrysene, benzo[a]pyrene, and coronene, were dominant in the particle phase. The highest PAH concentrations in both the vapor and particle phases were observed in Chicago followed by the semiurban site at Sturgeon Point, NY. The spatial difference of PAH concentrations can be explained by the local population density. Long-term decreasing trends of most PAH concentrations were observed in both the vapor and particle phases at Chicago, with half-lives ranging from 3-10 years in the vapor phase and 5-15 years in the particle phase. At Eagle Harbor, Sleeping Bear Dunes, and Sturgeon Point, total PAH concentrations in the vapor phase showed significant, but slow, long-term decreasing trends. At the Sturgeon Point site, which was impacted by a nearby city, particle-phase PAH concentrations also declined. However, most particle-phase PAH concentrations did not show significant long-term decreasing trends at the remote sites. Seasonal trends were also observed for particle-phase PAH concentrations, which were higher in the winter and lower in the summer.

Long-Term Stability of One-Inch Condenser Microphones Calibrated at the National Institute of Standards and Technology

PubMed Central

Wagner, Randall P.; Guthrie, William F.

2015-01-01

The devices calibrated most frequently by the acoustical measurement services at the National Institute of Standards and Technology (NIST) over the 50-year period from 1963 to 20121 were one-inch condenser microphones of three specific standard types: LS1Pn, LS1Po, and WS1P. Due to its long history of providing calibrations of such microphones to customers, NIST is in a unique position to analyze data concerning the long-term stability of these devices. This long history has enabled NIST to acquire and aggregate a substantial amount of repeat calibration data for a large number of microphones that belong to various other standards and calibration laboratories. In addition to determining microphone sensitivities at the time of calibration, it is important to have confidence that the microphones do not typically undergo significant drift as compared to the calibration uncertainty during the periods between calibrations. For each of the three microphone types, an average drift rate and approximate 95 % confidence interval were computed by two different statistical methods, and the results from the two methods were found to differ insignificantly in each case. These results apply to typical microphones of these types that are used in a suitable environment and handled with care. The average drift rate for Type LS1Pn microphones was −0.004 dB/year to 0.003 dB/year. The average drift rate for Type LS1Po microphones was −0.016 dB/year to 0.008 dB/year. The average drift rate for Type WS1P microphones was −0.004 dB/year to 0.018 dB/year. For each of these microphone types, the average drift rate is not significantly different from zero. This result is consistent with the performance expected of condenser microphones designed for use as transfer standards. In addition, the values that bound the confidence intervals are well within the limits specified for long-term stability in international standards. Even though these results show very good long-term stability historically for these microphone types, it is expected that periodic calibrations will always be done to track the calibration history of individual microphones and check for anomalies indicative of shifts in sensitivity. PMID:26958445

Spatial variation of PM2.5, PM10, PM2.5 absorbance and PMcoarse concentrations between and within 20 European study areas and the relationship with NO2 - Results of the ESCAPE project

NASA Astrophysics Data System (ADS)

Eeftens, Marloes; Tsai, Ming-Yi; Ampe, Christophe; Anwander, Bernhard; Beelen, Rob; Bellander, Tom; Cesaroni, Giulia; Cirach, Marta; Cyrys, Josef; de Hoogh, Kees; De Nazelle, Audrey; de Vocht, Frank; Declercq, Christophe; Dėdelė, Audrius; Eriksen, Kirsten; Galassi, Claudia; Gražulevičienė, Regina; Grivas, Georgios; Heinrich, Joachim; Hoffmann, Barbara; Iakovides, Minas; Ineichen, Alex; Katsouyanni, Klea; Korek, Michal; Krämer, Ursula; Kuhlbusch, Thomas; Lanki, Timo; Madsen, Christian; Meliefste, Kees; Mölter, Anna; Mosler, Gioia; Nieuwenhuijsen, Mark; Oldenwening, Marieke; Pennanen, Arto; Probst-Hensch, Nicole; Quass, Ulrich; Raaschou-Nielsen, Ole; Ranzi, Andrea; Stephanou, Euripides; Sugiri, Dorothee; Udvardy, Orsolya; Vaskövi, Éva; Weinmayr, Gudrun; Brunekreef, Bert; Hoek, Gerard

2012-12-01

The ESCAPE study (European Study of Cohorts for Air Pollution Effects) investigates relationships between long-term exposure to outdoor air pollution and health using cohort studies across Europe. This paper analyses the spatial variation of PM2.5, PM2.5 absorbance, PM10 and PMcoarse concentrations between and within 20 study areas across Europe.We measured NO2, NOx, PM2.5, PM2.5 absorbance and PM10 between October 2008 and April 2011 using standardized methods. PMcoarse was determined as the difference between PM10 and PM2.5. In each of the twenty study areas, we selected twenty PM monitoring sites to represent the variability in important air quality predictors, including population density, traffic intensity and altitude. Each site was monitored over three 14-day periods spread over a year, using Harvard impactors. Results for each site were averaged after correcting for temporal variation using data obtained from a reference site, which was operated year-round.Substantial concentration differences were observed between and within study areas. Concentrations for all components were higher in Southern Europe than in Western and Northern Europe, but the pattern differed per component with the highest average PM2.5 concentrations found in Turin and the highest PMcoarse in Heraklion. Street/urban background concentration ratios for PMcoarse (mean ratio 1.42) were as large as for PM2.5 absorbance (mean ratio 1.38) and higher than those for PM2.5 (1.14) and PM10 (1.23), documenting the importance of non-tailpipe emissions. Correlations between components varied between areas, but were generally high between NO2 and PM2.5 absorbance (average R2 = 0.80). Correlations between PM2.5 and PMcoarse were lower (average R2 = 0.39). Despite high correlations, concentration ratios between components varied, e.g. the NO2/PM2.5 ratio varied between 0.67 and 3.06.In conclusion, substantial variability was found in spatial patterns of PM2.5, PM2.5 absorbance, PM10 and PMcoarse. The highly standardized measurement of particle concentrations across Europe will contribute to a consistent assessment of health effects across Europe.

Alteration in certain enzymological parameters of an Indian major carp, Cirrhinus mrigala exposed to short- and long-term exposure of clofibric acid and diclofenac.

PubMed

Saravanan, Manoharan; Ramesh, Mathan; Petkam, Rakpong

2013-12-01

The extensive use of pharmaceuticals in human and veterinary medicine may enter the aquatic environment and pose a serious threat to non-target aquatic organisms like fish. In this study, Indian major carp Cirrhinus mrigala was exposed to different concentrations (1, 10 and 100 μg L⁻¹) of most commonly used pharmaceutical drugs clofibric acid (CA) and diclofenac (DCF) to evaluate its impacts on certain enzymological parameters during short- and long-term exposures. During short-term (96 h) exposure period, plasma glutamate oxaloacetate transaminase (GOT), glutamate pyruvate transaminase (GPT) and gill Na⁺/K⁺-ATPase activity were significantly altered at all concentrations of both the CA- and DCF-treated fish. In long-term exposure (35 days), gill Na⁺/K⁺-ATPase activity was found to be significantly increased at all concentration of CA and DCF exposures throughout the study period (except at the end of 7th day in 10 and 100 µg L⁻¹) . However, a biphasic trend was observed in plasma GOT and GPT activity when compared to the control groups. In both short- and long-term exposure, a significant (P < 0.01 and P < 0.05) changes were observed in all enzymological parameters of fish C. mrigala exposed to different concentrations of CA and DCF. The alterations of these enzymological parameters can be effectively used as potential biomarkers in monitoring of pharmaceutical toxicity in aquatic environment and organisms.

Long-term ammonia removal in a coconut fiber-packed biofilter: analysis of N fractionation and reactor performance under steady-state and transient conditions.

PubMed

Baquerizo, Guillermo; Maestre, Juan P; Machado, Vinicius C; Gamisans, Xavier; Gabriel, David

2009-05-01

A comprehensive study of long-term ammonia removal in a biofilter packed with coconut fiber is presented under both steady-state and transient conditions. Low and high ammonia loads were applied to the reactor by varying the inlet ammonia concentration from 90 to 260 ppm(v) and gas contact times ranging from 20 to 36 s. Gas samples and leachate measurements were periodically analyzed and used for characterizing biofilter performance in terms of removal efficiency (RE) and elimination capacity (EC). Also, N fractions in the leachate were quantified to both identify the experimental rates of nitritation and nitratation and to determine the N leachate distribution. Results showed stratification in the biofilter activity and, thus, most of the NH(3) removal was performed in the lower part of the reactor. An average EC of 0.5 kg N-NH(3)m(-3)d(-1) was obtained for the whole reactor with a maximum local average EC of 1.7 kg N-NH(3)m(-3)d(-1). Leachate analyses showed that a ratio of 1:1 of ammonium and nitrate ions in the leachate was obtained throughout steady-state operation at low ammonia loads with similar values for nitritation and nitratation rates. Low nitratation rates during high ammonia load periods occurred because large amounts of ammonium and nitrite accumulated in the packed bed, thus causing inhibition episodes on nitrite-oxidizing bacteria due to free ammonia accumulation. Mass balances showed that 50% of the ammonia fed to the reactor was oxidized to either nitrite or nitrate and the rest was recovered as ammonium indicating that sorption processes play a fundamental role in the treatment of ammonia by biofiltration.

Characteristics of Occupational Exposure to Benzene during Turnaround in the Petrochemical Industries.

PubMed

Chung, Eun-Kyo; Shin, Jung-Ah; Lee, Byung-Kyu; Kwon, Jiwoon; Lee, Naroo; Chung, Kwang-Jae; Lee, Jong-Han; Lee, In-Seop; Kang, Seong-Kyu; Jang, Jae-Kil

2010-09-01

The level of benzene exposure in the petrochemical industry during regular operation has been well established, but not in turnaround (TA), where high exposure may occur. In this study, the characteristics of occupational exposure to benzene during TA in the petrochemical companies were investigated in order to determine the best management strategies and improve the working environment. This was accomplished by evaluating the exposure level for the workers working in environments where benzene was being produced or used as an ingredient during the unit process. From 2003 to 2008, a total of 705 workers in three petrochemical companies in Korea were studied. Long- and short-term (< 1 hr) samples were taken during TAs. TA was classified into three stages: shut-down, maintenance and start-up. All works were classified into 12 occupation categories. The long-term geometric mean (GM) benzene exposure level was 0.025 (5.82) ppm (0.005-42.120 ppm) and the short-term exposure concentration during TA was 0.020 (17.42) ppm (0.005-61.855 ppm). The proportions of TA samples exceeding the time-weighted average, occupational exposure level (TWA-OEL in Korea, 1 ppm) and the short-term exposure limit (STEL-OEL, 5 ppm) were 4.1% (20 samples of 488) and 6.0% (13 samples of 217), respectively. The results for the benzene exposure levels and the rates of exceeding the OEL were both statistically significant (p < 0.05). Among the 12 job categories of petrochemical workers, mechanical engineers, plumbers, welders, fieldman and scaffolding workers exhibited long-term samples that exceeded the OEL of benzene, and the rate of exceeding the OEL was statistically significant for the first two occupations (p < 0.05). These findings suggest that the periodic work environment must be assessed during non-routine works such as TA.

Early Formation of Serum Advanced Glycation End-Products in Children with Type 1 Diabetes Mellitus: Relationship with Glycemic Control.

PubMed

Jaisson, Stéphane; Souchon, Pierre-François; Desmons, Aurore; Salmon, Anne-Sophie; Delemer, Brigitte; Gillery, Philippe

2016-05-01

To quantify serum advanced glycation end-products (AGEs) at the onset of type 1 diabetes mellitus and to determine their potential usefulness as retrospective indicators of glycemic balance. Carboxymethyllysine (CML) and pentosidine concentrations were determined by liquid chromatography-tandem mass spectrometry in 3 groups of children with type 1 diabetes mellitus: group (Gr) 1, subjects included at disease onset (n = 36); Gr2, subjects with diabetes of 5 years duration (n = 48); Gr3, subjects with diabetes of 10 years duration and in control subjects (n = 33). Hemoglobin A1c (HbA1c) values were recorded over the entire course of treatment for assessing long-term glycemic balance. Serum AGE concentrations were increased in all groups of subjects with diabetes compared with control subjects, but were highest in Gr1 (for CML: 0.155, 0.306, 0.219, and 0.224 mmol/mol Lys in control, Gr1, Gr2, and Gr3 subjects, respectively; for pentosidine: 312, 492, 365, and 403 nmol/mol Lys, respectively). AGE concentrations were closely correlated with HbA1c values (r = 0.78 for CML; r = 0.49 for pentosidine). In Gr2 and Gr3, the overall glycemic balance estimated by average HbA1c values was positively correlated with CML and pentosidine concentrations, especially in the first year of follow-up. Our results indicate that AGE concentrations are elevated in serum at the time of diabetes mellitus diagnosis, suggesting that the deleterious role of AGEs in the development of long-term complications should be taken into account even at the initial stages of the disease. Moreover, in some circumstances, AGEs could serve as surrogate markers of HbA1c for monitoring glycemic control. Copyright © 2016 Elsevier Inc. All rights reserved.

Dispersion modeling of polycyclic aromatic hydrocarbons from combustion of biomass and fossil fuels and production of coke in Tianjin, China.

PubMed

Tao, Shu; Li, Xinrong; Yang, Yu; Coveney, Raymond M; Lu, Xiaoxia; Chen, Haitao; Shen, Weiran

2006-08-01

A USEPA, procedure, ISCLT3 (Industrial Source Complex Long-Term), was applied to model the spatial distribution of polycyclic aromatic hydrocarbons (PAHs) emitted from various sources including coal, petroleum, natural gas, and biomass into the atmosphere of Tianjin, China. Benzo[a]pyrene equivalent concentrations (BaPeq) were calculated for risk assessment. Model results were provisionally validated for concentrations and profiles based on the observed data at two monitoring stations. The dominant emission sources in the area were domestic coal combustion, coke production, and biomass burning. Mainly because of the difference in the emission heights, the contributions of various sources to the average concentrations at receptors differ from proportions emitted. The shares of domestic coal increased from approximately 43% at the sources to 56% at the receptors, while the contributions of coking industry decreased from approximately 23% at the sources to 7% at the receptors. The spatial distributions of gaseous and particulate PAHs were similar, with higher concentrations occurring within urban districts because of domestic coal combustion. With relatively smaller contributions, the other minor sources had limited influences on the overall spatial distribution. The calculated average BaPeq value in air was 2.54 +/- 2.87 ng/m3 on an annual basis. Although only 2.3% of the area in Tianjin exceeded the national standard of 10 ng/m3, 41% of the entire population lives within this area.

Changes in the biomass and species composition of macroalgae in a eutrophic estuary

NASA Astrophysics Data System (ADS)

Lavery, Paul S.; Lukatelich, R. J.; McComb, A. J.

1991-07-01

More than 20 years of data are presented on the macroalgal biomass, species composition and water quality of Peel-Harvey estuary in south-western Australia. The occurrence of macroalgal blooms was a sudden event in the late 1960s, and appears to have resulted from nutrient availability surpassing a threshold of some kind. Cladophora dominated the system until 1979 and appears to have had a competitive advantage in deep-water areas because of its morphology. A catastrophic event compounded by a series of unfavourable conditions resulted in the loss of Cladophora from the deep areas and its estuary-wide replacement by Chaetomorpha, which was more competitive in the shallows. Since 1979, changes in water quality have been reflected in changes in biomass and species composition in the system. Average annual biomass is linearly related to average light attenuation over the summer growth period. Periods of high nutrient concentrations favour Ulva and Enteromorpha, while Chaetomorpha resumes dominance during periods of lower mean nutrient concentrations. Nutrient concentrations appear to be more influential on an inter-annual than seasonal scale, except in the case of Ulva which, on the basis of tissue N and P concentrations, is seasonally nitrogen-limited. Light attenuation appears to have seasonal and long-term effects. The data support the hypothesis of other workers that inter-annual differences in hydrographic events and phytoplankton dynamics influence macroalgal dynamics. The concept is examined further in light of this extensive database.

Biopersistences of man-made vitreous fibers and crocidolite fibers in rat lungs following short-term exposures.

PubMed Central

Musselman, R P; Miiller, W C; Eastes, W; Hadley, J G; Kamstrup, O; Thevenaz, P; Hesterberg, T W

1994-01-01

Biopersistence of commercial man-made vitreous fibers (MMVF) and crocidolite were studied in Fischer 344 rats. MMVF used were size-selected to be rat-respirable, and rats were exposed nose-only 6 h/day for 5 days to gravimetric concentrations (30 mg/m3) of two fiber glass compositions--a rockwool, and a slagwool--or to 10 mg/m3 of long-fibered crocidolite, or to filtered air. Animals were sacrificed at 1 hr, 1, 5, 31, 90, 180, 270, 365, and 545 days after exposure stopped. Fibers were recovered from digested lung tissue to determine changes in concentrations (fibers/mg dry lung) and fiber retentions (expressed as percent of day 1 retention [PR]) for selected dimension categories. One-day average concentrations of lung-retained MMVF and crocidolite fibers, of diameter > or = 0.5 micron or > 20 microns in length, were nearly equal, permitting direct comparisons between MMVF and crocidolite. At 270 days average PR for MMVF > or = 0.5 micron in diameter were from 3 to 6 +/- 2% and 27 +/- 9% for crocidolite. For fibers > 20 microns, PR were 1 to 4 +/- 4% for MMVF and 37 +/- 20% for crocidolite. At 545 days, MMVF > 20 microns in length were at background level while concentration of crocidolite fibers > 20 microns in length remained at 2000 +/- 400 f/mg DL (dry lung), or 38 +/- 9% of day-1 retention. These results suggest strongly that MMVF dissolved or fractured in vivo whereas crocidolite fibers did not change. PMID:7882918

Ambient Air Pollutants Have Adverse Effects on Insulin and Glucose Homeostasis in Mexican Americans

PubMed Central

Chen, Zhanghua; Salam, Muhammad T.; Toledo-Corral, Claudia; Watanabe, Richard M.; Xiang, Anny H.; Buchanan, Thomas A.; Habre, Rima; Bastain, Theresa M.; Lurmann, Fred; Wilson, John P.; Trigo, Enrique

2016-01-01

OBJECTIVE Recent studies suggest that air pollution plays a role in type 2 diabetes (T2D) incidence and mortality. The underlying physiological mechanisms have yet to be established. We hypothesized that air pollution adversely affects insulin sensitivity and secretion and serum lipid levels. RESEARCH DESIGN AND METHODS Participants were selected from BetaGene (n = 1,023), a study of insulin resistance and pancreatic β-cell function in Mexican Americans. All participants underwent DXA and oral and intravenous glucose tolerance tests and completed dietary and physical activity questionnaires. Ambient air pollutant concentrations (NO2, O3, and PM2.5) for short- and long-term periods were assigned by spatial interpolation (maximum interpolation radius of 50 km) of data from air quality monitors. Traffic-related air pollution from freeways (TRAP) was estimated using the dispersion model as NOx. Variance component models were used to analyze individual and multiple air pollutant associations with metabolic traits. RESULTS Short-term (up to 58 days cumulative lagged averages) exposure to PM2.5 was associated with lower insulin sensitivity and HDL-to-LDL cholesterol ratio and higher fasting glucose and insulin, HOMA-IR, total cholesterol, and LDL cholesterol (LDL-C) (all P ≤ 0.036). Annual average PM2.5 was associated with higher fasting glucose, HOMA-IR, and LDL-C (P ≤ 0.043). The effects of short-term PM2.5 exposure on insulin sensitivity were largest among obese participants. No statistically significant associations were found between TRAP and metabolic outcomes. CONCLUSIONS Exposure to ambient air pollutants adversely affects glucose tolerance, insulin sensitivity, and blood lipid concentrations. Our findings suggest that ambient air pollutants may contribute to the pathophysiology in the development of T2D and related sequelae. PMID:26868440

End-task versus in-task feedback to increase procedural learning retention during spinal anaesthesia training of novices.

PubMed

Lean, Lyn Li; Hong, Ryan Yee Shiun; Ti, Lian Kah

2017-08-01

Communication of feedback during teaching of practical procedures is a fine balance of structure and timing. We investigate if continuous in-task (IT) or end-task feedback (ET) is more effective in teaching spinal anaesthesia to medical students. End-task feedback was hypothesized to improve both short-term and long-term procedural learning retention as experiential learning promotes active learning after encountering errors during practice. Upon exposure to a 5-min instructional video, students randomized to IT or ET feedbacks were trained using a spinal simulator mannequin. A blinded expert tested the students using a spinal anaesthesia checklist in the short term (immediate) and long-term (average 4 months). Sixty-five students completed the training and testing. There were no differences in demographics of age or gender within IT or ET distributions. Both short-term and long-term learning retention of spinal anaesthesia ET feedback proved to be better (P < 0.01) than IT feedback. The time taken for ET students was shorter at long-term testing. End-task feedback improves both short-term and long-term procedural learning retention.

Preimpoundment hydrologic conditions in the Swatara Creek (1981- 84) and estimated postimpoundment water quality in and downstream from the planned Swatara State Park Reservoir, Lebanon and Schuylkill counties, Pennsylvania

USGS Publications Warehouse

Fishel, D.K.

1988-01-01

The hydrology and water quality of Swatara Creek were studied by the U.S. Geological Survey in cooperation with the Pennsylvania Department of Environmental Resources, Bureau of State Parks, from July 1981 through September 1984. The purpose of the study was to determine the effects of anthracite-coal mining and other point and nonpoint sources on the water quality of a planned 10,500 acre-foot reservoir. The Swatara State Park Reservoir is planned to be used for recreation and drinking-water supply for the city of Lebanon and surrounding communities. Annual precipitation during 1982, 1983, and 1984 was about 8 percent below, near normal, and 29 percent above the long-term average, respectively. The average annual precipitation during a year with near-normal precipitation, the 1983 water year, was 47 inches at Pine Grove. Mean streamflows during 1982, 1983, and 1984 were about 15 percent below, 4 percent above, and 50 percent above the long-term average, respectively. The average streamflow to the planned reservoir area during the 1983 water year was about 220 cubic feet per second. Inflows to, and downstream discharge from, the planned reservoir wer poorly buffered. Median alkalinity ranged from 4 to 7 mg/L (milligrams per liter) and median acidity ranged from 2 to 5 mg/L at the three sampling locations. Maximum total-recoverable iron, aluminum, and manganese concentrations were 100,000, 66,000, and 2,300 micrograms per liter, respectively. During 1983 the annual discharges of total-recoverable iron, aluminum, and manganese to the planned reservoir area were estimated to be 692, 300, and 95 tons, respectively. About 87 percent of the total-recoverable iron and 91 percent of total-recoverable sluminum measured was in the suspended phase. The data indicated that mine drainage affects the quality of Swatara Creek and will affect the quality of the planned reservoir. In addition to mine drainage, point-source nutrient and metal discharges will probably affect the planned reservoir. For example, in September 1983, Swatara Creek was sampled downstream from a point source. A dissolved- phosphorus concentration of 14 mg/L and total ammonia plus organic nitrogen concentration of 8.2 mg/L were measured. At the same location, concentrations of total-recoverable aluminum, chromium, copper, iron, and lead were 35, 300, 110, 1,300, and 32 micrograms per liter, respectively. Inflows to the planned Swatara State Park Reservoir are estimated to be acidic and rich in nutrients and select metals. Unless an effort is made to improve the quality of water from point and nonpoint sources, these conditions may impair the planned uses for the reservoir. Conservation releases from the reservoir need to be carefully controlled or these conditions also may degrade the water quality downstream.

Patterns and Rates of Historical Shoreline Change along the New England and Mid-Atlantic Coasts

NASA Astrophysics Data System (ADS)

Kratzmann, M. G.; Hapke, C. J.; Himmelstoss, E. A.; List, J. H.; Thieler, E. R.

2010-12-01

The U.S. Geological Survey is analyzing historical shoreline changes along open-ocean shores of the conterminous United States and parts of Hawaii, Alaska and the Great Lakes to calculate trends and rates of shoreline movement. This accurate and detailed coastal change information is necessary as growing coastal communities and infrastructure are threatened by erosion. Repeatable analytical methods were developed for shoreline movement calculations to facilitate periodic updates of coastal change in a systematic and internally consistent manner. The U.S. New England and Mid-Atlantic coasts from Maine to Virginia are the most recent to be completed in the National Assessment of Shoreline Change project. Shorelines from the 1800s through 2007 were derived from historical maps, orthophotos, and airborne lidar (1997-2007). All shoreline change rates are calculated using the Digital Shoreline Analysis System (DSAS) developed by the U.S. Geological Survey. Long-term rates of change are calculated using linear regression through all available shorelines (n = 4 to 12) for the full period of record (100-150 years). Short-term rates of change are calculated for the most recent 25-30 years, using the end-point method. Shoreline change rates were calculated for 78% of the 1360 km of coast in the study area. Complete coverage is lacking due to data gaps, as well as locations (rocky coastlines, large embayments, and beaches) where robust data are unavailable. The average rates of shoreline change for New England and the Mid-Atlantic are erosional, with higher erosion rates observed in the long-term than in the short-term. The average rates of long- and short-term shoreline change in New England (Maine, New Hampshire, Massachusetts, Rhode Island) are -0.4 m/yr ± 0.1 m/yr and -0.2 ± 0.09 m/yr, respectively. The average long-term rate in the Mid-Atlantic (New York, New Jersey, Delaware, Maryland, Virginia) is -0.6 ± 0.1 m/yr and the short-term rate of change is -0.3 ± 0.1 m/yr. In the Mid-Atlantic, there is a more pronounced difference in the percentage of erosional transects in the long-term (67%) than the short-term (54%), unlike the similar percentages of erosional transects in the long- (71%) and short-term (70%) within New England. However, the percentage of coastline eroding at higher rates (more than -3 m/yr) is greater in the short-term for both New England and the Mid-Atlantic, suggesting an increase in erosional hazards.

Calculation of average landslide frequency using climatic records

Treesearch

L. M. Reid

1998-01-01

Abstract - Aerial photographs are used to develop a relationship between the number of debris slides generated during a hydrologic event and the size of the event, and the long-term average debris-slide frequency is calculated from climate records using the relation.

Nitrogen fertilization decreases forest soil fungal and bacterial biomass in three long-term experiments

Treesearch

Matthew D. Wallenstein; Steven McNulty; Ivan J. Fernandez; Johnny Boggs; William H. Schlesinger

2006-01-01

We examined the effects of N fertilization on forest soil fungal and bacterial biomass at three long-term experiments in New England (Harvard Forest, MA; Mt. Ascutney, VT; Bear Brook, ME). At Harvard Forest, chronic N fertilization has decreased organic soil microbial biomass C (MBC) by an average of 54% and substrate induced respiration (SIR) was decreased by an...

Long-term predictive capability of erosion models

NASA Technical Reports Server (NTRS)

Veerabhadra, P.; Buckley, D. H.

1983-01-01

A brief overview of long-term cavitation and liquid impingement erosion and modeling methods proposed by different investigators, including the curve-fit approach is presented. A table was prepared to highlight the number of variables necessary for each model in order to compute the erosion-versus-time curves. A power law relation based on the average erosion rate is suggested which may solve several modeling problems.

Representativeness of shorter measurement sessions in long-term indoor air monitoring.

PubMed

Maciejewska, M; Szczurek, A

2015-02-01

Indoor air quality (IAQ) considerably influences health, comfort and the overall performance of people who spend most of their lives in confined spaces. For this reason, there is a strong need to develop methods for IAQ assessment. The fundamental issue in the quantitative determination of IAQ is the duration of measurements. Its inadequate choice may result in providing incorrect information and this potentially leads to wrong conclusions. The most complete information may be acquired through long-term monitoring. However it is typically perceived as impractical due to time and cost load. The aim of this study was to determine whether long-term monitoring can be adequately represented by a shorter measurement session. There were considered three measurable quantities: temperature, relative humidity and carbon dioxide concentration. They are commonly recognized as indicatives for IAQ and may be readily monitored. Scaled Kullback-Leibler divergence, also called relative entropy, was applied as a measure of data representativeness. We considered long-term monitoring in a range from 1 to 9 months. Based on our work, the representative data on CO2 concentration may be acquired while performing measurements during 20% of time dedicated to long-term monitoring. In the case of temperature and relative humidity the respective time demand was 50% of long-term monitoring. From our results, in indoor air monitoring strategies, there could be considered shorter measurement sessions, while still collecting data which are representative for long-term monitoring.

Airborne observations of cloud condensation nuclei spectra and aerosols over East Inner Mongolia

NASA Astrophysics Data System (ADS)

Yang, Jiefan; Lei, Hengchi; Lü, Yuhuan

2017-08-01

A set of vertical profiles of aerosol number concentrations, size distributions and cloud condensation nuclei (CCN) spectra was observed using a passive cloud and aerosol spectrometer (PCASP) and cloud condensation nuclei counter, over the Tongliao area, East Inner Mongolia, China. The results showed that the average aerosol number concentration in this region was much lower than that in heavily polluted areas. Monthly average aerosol number concentrations within the boundary layer reached a maximum in May and a minimum in September, and the variations in CCN number concentrations at different supersaturations showed the same trend. The parameters c and k of the empirical function N = cS k were 539 and 1.477 under clean conditions, and their counterparts under polluted conditions were 1615 and 1.42. Measurements from the airborne probe mounted on a Yun-12 (Y12) aircraft, together with Hybrid Single-Particle Lagrangian Integrated Trajectory model backward trajectories indicated that the air mass from the south of Tongliao contained a high concentration of aerosol particles (1000-2500 cm-3) in the middle and lower parts of the troposphere. Moreover, detailed intercomparison of data obtained on two days in 2010 indicated that the activation efficiency in terms of the ratio of N CCN to N a (aerosols measured from PCASP) was 0.74 (0.4 supersaturations) when the air mass mainly came from south of Tongliao, and this value increased to 0.83 on the relatively cleaner day. Thus, long-range transport of anthropogenic pollutants from heavily polluted mega cities, such as Beijing and Tianjin, may result in slightly decreasing activation efficiencies.

Relevance analysis and short-term prediction of PM2.5 concentrations in Beijing based on multi-source data

NASA Astrophysics Data System (ADS)

Ni, X. Y.; Huang, H.; Du, W. P.

2017-02-01

The PM2.5 problem is proving to be a major public crisis and is of great public-concern requiring an urgent response. Information about, and prediction of PM2.5 from the perspective of atmospheric dynamic theory is still limited due to the complexity of the formation and development of PM2.5. In this paper, we attempted to realize the relevance analysis and short-term prediction of PM2.5 concentrations in Beijing, China, using multi-source data mining. A correlation analysis model of PM2.5 to physical data (meteorological data, including regional average rainfall, daily mean temperature, average relative humidity, average wind speed, maximum wind speed, and other pollutant concentration data, including CO, NO2, SO2, PM10) and social media data (microblog data) was proposed, based on the Multivariate Statistical Analysis method. The study found that during these factors, the value of average wind speed, the concentrations of CO, NO2, PM10, and the daily number of microblog entries with key words 'Beijing; Air pollution' show high mathematical correlation with PM2.5 concentrations. The correlation analysis was further studied based on a big data's machine learning model- Back Propagation Neural Network (hereinafter referred to as BPNN) model. It was found that the BPNN method performs better in correlation mining. Finally, an Autoregressive Integrated Moving Average (hereinafter referred to as ARIMA) Time Series model was applied in this paper to explore the prediction of PM2.5 in the short-term time series. The predicted results were in good agreement with the observed data. This study is useful for helping realize real-time monitoring, analysis and pre-warning of PM2.5 and it also helps to broaden the application of big data and the multi-source data mining methods.

Antihypertensive effect of long-term oral administration of jellyfish (Rhopilema esculentum) collagen peptides on renovascular hypertension.

PubMed

Zhuang, Yongliang; Sun, Liping; Zhang, Yufeng; Liu, Gaoxiang

2012-02-01

Antihypertensive effect of long-term oral administration of jellyfish (Rhopilema esculentum) collagen peptides (JCP) on renovascular hypertension rats (RVHs) was evaluated. The systolic blood pressure and diastolic blood pressure of the RVHs were significantly reduced with administration of JCP (p < 0.05), compared with model control group. However, the arterial blood pressure of normal rats showed no significant changes during long-term oral treatment with high dose JCP (p > 0.05). Furthermore, effect of JCP on angiotensin II (Ang II) concentration of plasma had no significance (p > 0.05), but JCP significantly inhibited the Ang II concentration in RVHs' kidney (p < 0.05). The kidney should be the target site of JCP.

Antihypertensive Effect of Long-Term Oral Administration of Jellyfish (Rhopilema esculentum) Collagen Peptides on Renovascular Hypertension

PubMed Central

Zhuang, Yongliang; Sun, Liping; Zhang, Yufeng; Liu, Gaoxiang

2012-01-01

Antihypertensive effect of long-term oral administration of jellyfish (Rhopilema esculentum) collagen peptides (JCP) on renovascular hypertension rats (RVHs) was evaluated. The systolic blood pressure and diastolic blood pressure of the RVHs were significantly reduced with administration of JCP (p < 0.05), compared with model control group. However, the arterial blood pressure of normal rats showed no significant changes during long-term oral treatment with high dose JCP (p > 0.05). Furthermore, effect of JCP on angiotensin II (Ang II) concentration of plasma had no significance (p > 0.05), but JCP significantly inhibited the Ang II concentration in RVHs’ kidney (p < 0.05). The kidney should be the target site of JCP. PMID:22412809

A short history of the development of the Turc-Mezentsev water balance formula

NASA Astrophysics Data System (ADS)

Andréassian, Vazken; Lebecherel, Laure

2013-04-01

In the 1950s, a formula linking long term average evaporation to long-term average precipitation and potential evaporation was quasi-simultaneously proposed in France and in the Soviet Union. However, because Turc and Mezentsev published in French and Russian respectively, their work has received limited attention, and the formula they proposed is often given different names. • Work of Lucien Turc in France (1954) Lucien Turc, a French soil scientist, worked at the Versailles soil science laboratory of the French National Agronomical Research Institute. For agronomic purposes, he was interested in developing a formula to estimate actual evapotranspiration from precipitation and temperature data. Since lysimeter data were so scarce at that time, he had the idea to derive such a formula from catchment water balance. With the help of the hydrologist Maurice Pardé, he assembled a set of data on 254 catchments from all over the world. He derived long-term average actual evapotranspiration (E) from estimates of long-term average precipitation (P) and long-term average discharge (Q). Then, Turc looked for a mathematical function linking two non-dimensional terms: the aridity index (the ratio of precipitation P and potential evapotranspiration E0) and the evapotranspiration rate (the ratio of E and E0). He proposed the following formulation: E/P=1/[1+(P/E0)**n]**(1/n) in which n is an exponent to estimate. Turc graphically looked for the most convenient value for n, and concluded that the best fit was "with n=3, or may be n=2" (Turc, 1954, p.563). • Work of Varfolomeï Mezentsev in the Soviet Union (1955) Mezentsev (1955) worked at the University of Omsk in Siberia. He started his analysis from a formula proposed by Bagrov (1953): dE/dP=1-(E/E0)**n (Eq.1) This formula presents the interesting property to integrate into the Schreiber (1904) water balance formula for n=1:and into the Ol'Dekop (1911) water balance formula for n=2. But it had no analytical solution for other values of n. Mezentsev (1955) complexified Bagrov's formula by rewriting it as follows: dE/dP=[1-(E/E0)**n]**(1+1/n) (Eq.2) which keeps the same interpretation as Eq. 1. Eq. 2 can be integrated analytically and yields Eq. 3: E/P=1/[1+(P/E0)**n]**(1/n) (Eq.3) which is identical to the general formulation proposed by Turc. Based on a set of 35 catchments of the Siberian plateau, Mezentsev suggested using the value of 2.3 for parameter n, which is close to the value advised by Turc. References Bagrov, N. A., 1953. O srednem mnogoletnem ispraeniiz c paverknosti sushi (on the average long-term evaporation from the land surface), Meteorologia i Gidrologia, 10, 20-25. Mezentsev, V., 1955. More on the computation of total evaporation (Yechio raz o rastchetie srednevo summarnovo ispareniia). Meteorologia i Gidrologia, 5: 24-26. Turc, L., 1954. Le bilan d'eau des sols: relation entre les précipitations, l'évaporation et l'écoulement. Annales Agronomiques, Série A(5): 491-595.

Stochastic Modeling of Soil Salinity

NASA Astrophysics Data System (ADS)

Suweis, Samir; Rinaldo, Andrea; van der Zee, Sjoerd E. A. T. M.; Maritan, Amos; Porporato, Amilcare

2010-05-01

Large areas of cultivated land worldwide are affected by soil salinity. Estimates report that 10% of arable land in over 100 countries, and nine million km2 are salt affected, especially in arid and semi-arid regions. High salinity causes both ion specific and osmotic stress effects, with important consequences for plant production and quality. Salt accumulation in the root zone may be due to natural factors (primary salinization) or due to irrigation (secondary salinization). Simple (e.g., vertically averaged over the soil depth) coupled soil moisture and salt balance equations have been used in the past. Despite their approximations, these models have the advantage of parsimony, thus allowing a direct analysis of the interplay of the main processes. They also provide the ideal starting point to include external, random hydro-climatic fluctuations in the analysis of long-term salinization trends. We propose a minimalist stochastic model of primary soil salinity, in which the rate of soil salinization is determined by the balance between dry and wet salt deposition and the intermittent leaching events caused by rainfall events. The long term probability density functions of salt mass and concentration are found by reducing the coupled soil moisture and salt mass balance equation to a stochastic differential equation driven by multiplicative Poisson noise. The novel analytical solutions provide insight on the interplay of the main soil, plant and climate parameters responsible for long-term soil salinization. In fact, soil salinity statistics are obtained as a function of climate, soil and vegetation parameters. These, in turn, can be combined with soil moisture statistics to obtain a full characterization of soil salt concentrations and the ensuing risk of primary salinization. In particular, the solutions show the existence of two quite distinct regimes, the first one where the mean salt mass remains nearly constant with increasing rainfall frequency, and the second one where mean salt content increases markedly with increasing rainfall frequency. As a result, relatively small reductions of rainfall in drier climates may entail dramatic shifts in long-term soil salinization trends, with significant consequences e.g. for climate change impacts on rain-fed agriculture. The analytical nature of the solution allows direct estimation of the impact of changes in the climatic drivers on soil salinity and makes it suitable for computations of salinity risk at the global scale as a function of simple parameters. Moreover it facilitates their coupling with other models of long-term soil-plant biogeochemistry.

Long-term interventions effects of robotic training on patients after anterior cruciate ligament reconstruction.

PubMed

Hu, Chunying; Huang, Qiuchen; Yu, Lili; Zhou, Yue; Gu, Rui; Ye, Miao; Ge, Meng; Xu, Yanfeng; Liu, Jianfeng

2016-08-01

[Purpose] The aim of this study was to examine the long-term interventions effects of robot-assisted therapy rehabilitation on functional activity levels after anterior cruciate ligament reconstruction. [Subjects and Methods] The subjects were 8 patients (6 males and 2 females) who received anterior cruciate ligament reconstruction. The subjects participated in robot-assisted therapy lasting for one month. The Timed Up-and-Go test, 10-Meter Walk test, Functional Reach Test, surface electromyography of the vastus lateralis and vastus medialis, and extensor strength of isokinetic movement of the knee joint were evaluated before and after the intervention. [Results] The average value of the of vastus medialis EMG, Functional Reach Test, and the maximum and average extensor strength of the knee joint isokinetic movement increased significantly, and the time of the 10-Meter Walk test decreased significantly. [Conclusion] These results suggest that walking ability and muscle strength can be improved by robotic walking training as a long-term intervention.

Long-term interventions effects of robotic training on patients after anterior cruciate ligament reconstruction

PubMed Central

Hu, Chunying; Huang, Qiuchen; Yu, Lili; Zhou, Yue; Gu, Rui; Ye, Miao; Ge, Meng; Xu, Yanfeng; Liu, Jianfeng

2016-01-01

[Purpose] The aim of this study was to examine the long-term interventions effects of robot-assisted therapy rehabilitation on functional activity levels after anterior cruciate ligament reconstruction. [Subjects and Methods] The subjects were 8 patients (6 males and 2 females) who received anterior cruciate ligament reconstruction. The subjects participated in robot-assisted therapy lasting for one month. The Timed Up-and-Go test, 10-Meter Walk test, Functional Reach Test, surface electromyography of the vastus lateralis and vastus medialis, and extensor strength of isokinetic movement of the knee joint were evaluated before and after the intervention. [Results] The average value of the of vastus medialis EMG, Functional Reach Test, and the maximum and average extensor strength of the knee joint isokinetic movement increased significantly, and the time of the 10-Meter Walk test decreased significantly. [Conclusion] These results suggest that walking ability and muscle strength can be improved by robotic walking training as a long-term intervention. PMID:27630396

National assessment of shoreline change—Summary statistics for updated vector shorelines and associated shoreline change data for the Gulf of Mexico and Southeast Atlantic coasts

USGS Publications Warehouse

Himmelstoss, Emily A.; Kratzmann, Meredith G.; Thieler, E. Robert

2017-07-18

Long-term rates of shoreline change for the Gulf of Mexico and Southeast Atlantic regions of the United States have been updated as part of the U.S. Geological Survey’s National Assessment of Shoreline Change project. Additional shoreline position data were used to compute rates where the previous rate-of-change assessment only included four shoreline positions at a given location. The long-term shoreline change rates also incorporate the proxy-datum bias correction to account for the unidirectional onshore bias of the proxy-based high water line shorelines relative to the datum-based mean high water shorelines. The calculation of uncertainty associated with the long-term average rates has also been updated to match refined methods used in other study regions of the National Assessment project. The average rates reported here have a reduced amount of uncertainty relative to those presented in the previous assessments for these two regions.

[Characteristics of atmospheric CO2 concentration and variation of carbon source & sink at Lin'an regional background station].

PubMed

Pu, Jing-Jiao; Xu, Hong-Hui; Kang, Li-Li; Ma, Qian-Li

2011-08-01

Characteristics of Atmospheric CO2 concentration obtained by Flask measurements were analyzed at Lin'an regional background station from August 2006 to July 2009. According to the simulation results of carbon tracking model, the impact of carbon sources and sinks on CO2 concentration was evaluated in Yangtze River Delta. The results revealed that atmospheric CO2 concentrations at Lin'an regional background station were between 368.3 x 10(-6) and 414.8 x 10(-6). The CO2 concentration varied as seasons change, with maximum in winter and minimum in summer; the annual difference was about 20.5 x 10(-6). The long-term trend of CO2 concentration showed rapid growth year by year; the average growth rate was about 3.2 x 10(-6)/a. CO2 flux of Yangtze River Delta was mainly contributed by fossil fuel burning, terrestrial biosphere exchange and ocean exchange, while the contribution of fire emission was small. CO2 flux from fossil fuel burning played an important role in carbon source; terrestrial biosphere and ocean were important carbon sinks in this area. Seasonal variations of CO2 concentration at Lin'an regional background station were consistent with CO2 fluxes from fossil fuel burning and terrestrial biosphere exchange.

Temporal changes in nitrogen and phosphorus concentrations with comparisons to conservation practices and agricultural activities in the Lower Grand River, Missouri and Iowa, and selected watersheds, 1969–2015

USGS Publications Warehouse

Krempa, Heather M.; Flickinger, Allison K.

2017-08-01

This report presents the results of a cooperative study by the U.S. Geological Survey and Missouri Department of Natural Resources to estimate total nitrogen (TN) and total phosphorus (TP) concentrations at monitoring sites within and near the Lower Grand River hydrological unit. The primary objectives of the study were to quantify temporal changes in TN and TP concentrations and compare those concentrations to conservation practices and agricultural activities. Despite increases in funding during 2011–15 for conservation practices in the Lower Grand River from the Mississippi River Basin Healthy Watersheds Initiative, decreases in flow-normalized TN and TP concentrations during this time at the long-term Grand River site were less than at other long-term sites, which did not receive funding from the Mississippi River Basin Healthy Watersheds Initiative. The relative differences in the magnitude of flow-normalized TN and TP concentrations among long-term sites are directly related to the amount of agricultural land use within the watershed. Significant relations were determined between nitrogen from cattle manure and flow-normalized TN concentrations at selected long-term sites, indicating livestock manure may be a substantial source of nitrogen within the selected long-term site watersheds. Relations between flow-normalized TN and TP concentrations with Conservation Reserve Program acres and with nitrogen and phosphorus from commercial fertilizer indicate that changes in these factors alone did not have a substantial effect on stream TN and TP concentrations; other landscape activities, runoff, within-bank nutrients that are suspended during higher streamflows, or a combination of these have had a greater effect on stream TN and TP concentrations; or there is a lag time that is obscuring relations. Temporal changes in flow-adjusted TN and TP concentrations were not substantial at Lower Grand River Mississippi River Basin Healthy Watersheds Initiative sites, indicating factors besides stream variability did not have substantial effects on TN and TP concentrations. Flow-weighted TN and TP concentrations at Lower Grand River Mississippi River Basin Healthy Watershed Initiative sites increase with increasing streamflow, which indicates runoff, within-bank nutrients that are suspended during higher streamflows, or both, have more effect on stream TN and TP concentrations than consistent point sources or groundwater sources. Timing of TN and TP concentration increases compared to streamflow increases indicate that nitrogen and phosphorus loads are more strongly related to streamflow than to a particular period of the year, indicating that runoff, within-bank nutrients that are suspended during higher streamflows, or both are a substantial source of nutrients regardless of timing.

Space-for-time substitution in predicting the state of picoplankton and nanoplankton in a changing Arctic Ocean

NASA Astrophysics Data System (ADS)

Li, William K. W.; Carmack, Eddy C.; McLaughlin, Fiona A.; Nelson, R. John; Williams, William J.

2013-10-01

The Arctic Ocean is changing rapidly but there are no long-term time series observations on the state of the phytoplankton community that could allow a link to be made from physical/chemical pressures to the impact on marine ecosystems. Here, we test the idea that space-for-time (SFT) substitution might predict temporal change in the Canada Basin premised on differences in the present state of phytoplankton in other geographic zones, specifically the ratio in the abundance of picophytoplankton to nanophytoplankton (Pico:Nano). We compared the change in Pico:Nano observed in the Canada Basin from 2004 to 2012 to the different average states of this ratio in 26 other ocean ecological regions. Our results show that as upper ocean nitrate concentration changed in the Canada Basin from year to year, the concomitant change in Pico:Nano was statistically commensurate with the difference that this ratio exhibits between Longhurst ecological provinces in relation to nitrate concentration. Lower average concentration of nitrate in the upper water column is associated with a higher value of Pico:Nano, a result consistent with resource control of phytoplankton size structure in the ocean. We suggest that SFT substitution allows an explanation of temporal progression from spatial pattern as a test of mechanism, but such statistical prediction is not necessarily a projection of future states.

Looking for a relevant potential evapotranspiration model at the watershed scale

NASA Astrophysics Data System (ADS)

Oudin, L.; Hervieu, F.; Michel, C.; Perrin, C.; Anctil, F.; Andréassian, V.

2003-04-01

In this paper, we try to identify the most relevant approach to calculate Potential Evapotranspiration (PET) for use in a daily watershed model, to try to bring an answer to the following question: "how can we use commonly available atmospheric parameters to represent the evaporative demand at the catchment scale?". Hydrologists generally see the Penman model as the ideal model regarding to its good adequacy with lysimeter measurements and its physically-based formulation. However, in real-world engineering situations, where meteorological stations are scarce, hydrologists are often constrained to use other PET formulae with less data requirements or/and long-term average of PET values (the rationale being that PET is an inherently conservative variable). We chose to test 28 commonly used PET models coupled with 4 different daily watershed models. For each test, we compare both PET input options: actual data and long-term average data. The comparison is made in terms of streamflow simulation efficiency, over a large sample of 308 watersheds. The watersheds are located in France, Australia and the United States of America and represent varied climates. Strikingly, we find no systematic improvements of the watershed model efficiencies when using actual PET series instead of long-term averages. This suggests either that watershed models may not conveniently use the climatic information contained in PET values or that formulae are only awkward indicators of the real PET which watershed models need.

Effects of Bedrock Landsliding on Cosmogenically Determined Erosion Rates

NASA Technical Reports Server (NTRS)

Niemi, Nathan; Oskin, Mike; Burbank, Douglas; Heimsath, Arjun

2005-01-01

The successful quantification of long-term erosion rates underpins our understanding of landscape. formation, the topographic evolution of mountain ranges, and the mass balance within active orogens. The measurement of in situ-produced cosmogenic radionuclides (CRNs) in fluvial and alluvial sediments is perhaps the method with the greatest ability to provide such long-term erosion rates. In active orogens, however, deep-seated bedrock landsliding is an important erosional process, the effect of which on CRN-derived erosion rates is largely unquantified. We present a numerical simulation of cosmogenic nuclide production and distribution in landslide-dominated catchments to address the effect of bedrock landsliding on cosmogenic erosion rates in actively eroding landscapes. Results of the simulation indicate that the temporal stability of erosion rates determined from CRN concentrations in sediment decreases with increased ratios of landsliding to sediment detachment rates within a given catchment area, and that larger catchment areas must be sampled with increased frequency of landsliding in order to accurately evaluate long-term erosion rates. In addition, results of this simulation suggest that sediment sampling for CRNs is the appropriate method for determining long-term erosion rates in regions dominated by mass-wasting processes, while bedrock surface sampling for CRNs is generally an ineffective means of determining long-term erosion rates. Response times of CRN concentrations to changes in erosion rate indicate that climatically driven cycles of erosion may be detected relatively quickly after such changes occur, but that complete equilibration of CRN concentrations to new erosional conditions may take tens of thousands of years. Simulation results of CRN erosion rates are compared with a new, rich dataset of CRN concentrations from the Nepalese Himalaya, supporting conclusions drawn from the simulation.

Long term trends in sewage abatement and water quality in the Hudson-Raritan Estuary

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brosnan, T.M.; O`Shea, M.L.

1995-12-31

Long-term trends in dissolved oxygen (DO) and coliform bacteria concentrations are used to evaluate the impact of 70 years of sewage abatement and treatment in the Hudson-Raritan Estuary near New York City (NYC). Regional construction of wastewater treatment plants since the 1920`s has reduced discharges of untreated sewage into the estuary from approximately 47 M{sup 3}/S in 1936 to less than 0.1 M{sup 3}/S by 1994. From at least 1922 through the early 1960s, average summer DO percent saturation in the Hudson River varied between 35--50% in surface waters and 25--40% in bottom waters. Beginning in the late 1970s, DOmore » concentrations increased through the 1980s and especially into the 1990s, coinciding with the secondary treatment upgrade of the 7.4 M3/s North River plant in the spring of 1991. Average summer percent saturation in the early 1 990s exceeded 80% in surface waters and 60% in bottom waters. In addition, summer DO minima increased from less than 1.5 mg/L in the early 1970s, to greater than 3.0 mg/L in the 1990s, and the duration of hypoxia during summer months has been reduced. While this general trend has been observed throughout the estuary, some areas have displayed recent declines in DO, possibly due to increasing eutrophication. Total coliforms also display strong decreasing trends from the 1960s into the 1990s, with declines attributed to plant construction and expansion, and improved operation of the sewer system. Metal loadings have also decreased significantly. Signs of improved ecosystem quality include reopened beaches and shellfish beds, re-infestation of woodpilings by marine wood-borers, and the resurgence of wading birds in several areas of the estuary.« less

Short-term air pollution exposure aggravates Parkinson’s disease in a population-based cohort

PubMed Central

Lee, Hyewon; Myung, Woojae; Kim, Doh Kwan; Kim, Satbyul Estella; Kim, Clara Tammy; Kim, Ho

2017-01-01

Increasing experimental evidence has suggested air pollution as new risk factor for neurological disease. Although long-term exposure is reportedly related to neurological disease, information on association with short-term exposure is scarce. We examined the association of short-term exposure to particles <2.5 μm (PM2.5), nitrogen dioxide (NO2), sulfur dioxide (SO2), ozone (O3), and carbon monoxide (CO) with PD aggravation in Seoul from the National Health Insurance Service–National Sample Cohort, Korea during 2002–2013. PD aggravation cases were defined as emergency hospital admissions for primarily diagnosed PD and analyzed with a case-crossover analysis, designed for rare acute outcomes. Pollutants concentrations on case and control days were compared and effect modifications were explored. A unit increase in 8-day moving average of concentrations was significantly associated with PD aggravation. The association was consistent for PM2.5 (odds ratio [95% confidence interval]: 1.61 [1.14–2.29] per 10 μg/m3), NO2 (2.35 [1.39–3.97] per 10 ppb), SO2 (1.54 [1.11–2.14] per 1 ppb), and CO (1.46 [1.05–2.04] per 0.1 ppm). The associations were stronger in women, patients aged 65–74 years, and cold season, but not significant. In conclusion, short-term air pollution exposure increased risk of PD aggravation, and may cause neurological disease progression in humans. PMID:28300224

7 CFR 3555.10 - Definitions and abbreviations.

Code of Federal Regulations, 2014 CFR

2014-01-01

... perpetuity, primarily for conveyance under long-term ground leases. See section 502(a)(3)(B) of the Housing... fully repay the unpaid principal balance over the mortgage term. Amortized payment. Equal monthly... principal over the term of the loan. Annual fee. A periodic amount that is based on the average annual...

Temporal modelling and forecasting of the airborne pollen of Cupressaceae on the southwestern Iberian Peninsula.

PubMed

Silva-Palacios, Inmaculada; Fernández-Rodríguez, Santiago; Durán-Barroso, Pablo; Tormo-Molina, Rafael; Maya-Manzano, José María; Gonzalo-Garijo, Ángela

2016-02-01

Cupressaceae includes species cultivated as ornamentals in the urban environment. This study aims to investigate airborne pollen data for Cupressaceae on the southwestern Iberian Peninsula over a 21-year period and to analyse the trends in these data and their relationship with meteorological parameters using time series analysis. Aerobiological sampling was conducted from 1993 to 2013 in Badajoz (SW Spain). The main pollen season for Cupressaceae lasted, on average, 58 days, ranging from 55 to 112 days, from 24 January to 22 March. Furthermore, a short-term forecasting model has been developed for daily pollen concentrations. The model proposed to forecast the airborne pollen concentration is described by one equation. This expression is composed of two terms: the first term represents the pollen concentration trend in the air according to the average concentration of the previous 10 days; the second term is obtained from considering the actual pollen concentration value, which is calculated based on the most representative meteorological parameters multiplied by a fitting coefficient. Temperature was the main meteorological factor by its influence over daily pollen forecast, being the rain the second most important factor. This model represents a good approach to a continuous balance model of Cupressaceae pollen concentration and is supported by a close agreement between the observed and predicted mean concentrations. The novelty of the proposed model is the analysis of meteorological parameters that are not frequently used in Aerobiology.

Phytoestrogens and Their Metabolites in Bulk-Tank Milk: Effects of Farm Management and Season

PubMed Central

Adler, Steffen A.; Purup, Stig; Hansen-Møller, Jens; Thuen, Erling; Steinshamn, Håvard

2015-01-01

Phytoestrogens have structures similar to endogenous steroids and may induce or inhibit the response of hormone receptors. The objectives of the present study were to compare the effects of long-term vs. short-term grassland management in organic and conventional dairy production systems, compare organic and conventional production systems and assess seasonal variation on phytoestrogen concentrations in bulk-tank milk. The concentrations of phytoestrogens were analyzed in bulk-tank milk sampled three times in two subsequent years from 28 dairy farms: Fourteen organic (ORG) dairy farms with either short-term or long-term grassland management were paired with 14 conventional (CON) farms with respect to grassland management. Grassland management varied in terms of time since establishment. Short-term grassland management (SG) was defined as establishment or reseeding every fourth year or more often, and long-term grassland management (LG) was defined as less frequent establishment or reseeding. The proportion of red clover (Trifolium pretense L.) in the herbage was positively correlated with milk concentrations of the mammalian isoflavone equol. Therefore, organically produced bulk-tank milk contained more equol than conventionally produced milk, and milk from ORG-SG farms had more equol than milk from ORG-LG farms. Milk produced during the indoor-feeding periods had more equol than milk produced during the outdoor feeding period, because pastures contained less red clover than fields intended for silage production. Organically produced milk had also higher concentrations of the mammalian lignan enterolactone, but in contrast to equol, concentrations increased in the outdoor-feeding periods compared to the indoor-feeding periods. There were no indications of fertility problems on ORG-SG farms who had the highest red clover proportions in the herbage. This study shows that production system, grassland management, and season affect milk concentrations of phytoestrogens. However, compared to soy products, milk concentrations of phytoestrogens are low and future studies are required to investigate if the intake of phytoestrogens from dairy products has physiological effects in humans. PMID:25996600

Hip protector compliance: a 13-month study on factors and cost in a long-term care facility.

PubMed

Burl, Jeffrey B; Centola, James; Bonner, Alice; Burque, Colleen

2003-01-01

To determine if a high compliance rate for wearing external hip protectors could be achieved and sustained in a long-term care population. A 13-month prospective study of daytime use of external hip protectors in an at-risk long-term care population. One hundred-bed not-for-profit long-term care facility. Thirty-eight ambulatory residents having at least 1 of 4 risk factors (osteoporosis, recent fall, positive fall screen, previous fracture). The rehabilitation department coordinated an implementation program. Members of the rehabilitation team met with eligible participants, primary caregivers, families, and other support staff for educational instruction and a description of the program. The rehabilitation team assumed overall responsibility for measuring and ordering hip protectors and monitoring compliance. By the end of the third month, hip protector compliance averaged greater than 90% daily wear. The average number of falls per month in the hip protector group was 3.9 versus 1.3 in nonparticipants. Estimated total indirect staff time was 7.75 hours. The total cost of the study (hip protectors and indirect staff time) was 6,300 US dollars. High hip protector compliance is both feasible and sustainable in an at-risk long-term care population. Achieving high compliance requires an interdisciplinary approach with one department acting as a champion. The cost of protectors could be a barrier to widespread use. Facilities might be unable to cover the cost until the product is paid for by third-party payers.

Processing short-term and long-term information with a combination of polynomial approximation techniques and time-delay neural networks.

PubMed

Fuchs, Erich; Gruber, Christian; Reitmaier, Tobias; Sick, Bernhard

2009-09-01

Neural networks are often used to process temporal information, i.e., any kind of information related to time series. In many cases, time series contain short-term and long-term trends or behavior. This paper presents a new approach to capture temporal information with various reference periods simultaneously. A least squares approximation of the time series with orthogonal polynomials will be used to describe short-term trends contained in a signal (average, increase, curvature, etc.). Long-term behavior will be modeled with the tapped delay lines of a time-delay neural network (TDNN). This network takes the coefficients of the orthogonal expansion of the approximating polynomial as inputs such considering short-term and long-term information efficiently. The advantages of the method will be demonstrated by means of artificial data and two real-world application examples, the prediction of the user number in a computer network and online tool wear classification in turning.

Municipal sludge metal contamination of old-field ecosystems: Do liming and tilling affect remediation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Benninger-Truax, M.; Taylor, D.H.

1993-10-01

Mechanisms of ecosystem recovery following 11 years of sewage sludge disposal were addressed by examining the effects of tilling and/or liming on soil chemistry and the heavy metal (Cd, Cu, Pb, and Zn) concentrations in soil, earthworms, vegetation, spiders, and crickets. In 1989 and 1990, subplots in each of three former 0.1-ha, long-term treatments (sludge, fertilizer, and control) were either unmanipulated or manipulated via tilling and/or liming. Liming significantly increased the pH of soil from the long-term sludge and fertilizer plots, and the combination of tilling and liming affected the heavy metal concentrations in earthworms, as lower concentrations of Cd,more » Cu, Pb, and Zn were found in earthworms collected from subplots that had been both tilled and limed. However, most observed significant differences in heavy metal concentrations reflected the long-term treatments, as heavy metal concentrations tended to be greater in the soil and biota collected from sludge-treated plots. Thus, heavy metals remained in the soil in forms available to the biota, regardless of the cessation of sludge application or subplot manipulations (liming and/or tilling) for two years following cessation of sludge application.« less

Estimating Pesticide Exposure from Dietary Intake and Organic Food Choices: The Multi-Ethnic Study of Atherosclerosis (MESA)

PubMed Central

Beresford, Shirley A.A.; Fenske, Richard A.; Fitzpatrick, Annette L.; Lu, Chensheng; Nettleton, Jennifer A.; Kaufman, Joel D.

2015-01-01

Background Organophosphate pesticide (OP) exposure to the U.S. population is dominated by dietary intake. The magnitude of exposure from diet depends partly on personal decisions such as which foods to eat and whether to choose organic food. Most studies of OP exposure rely on urinary biomarkers, which are limited by short half-lives and often lack specificity to parent compounds. A reliable means of estimating long-term dietary exposure to individual OPs is needed to assess the potential relationship with adverse health effects. Objectives We assessed long-term dietary exposure to 14 OPs among 4,466 participants in the Multi-Ethnic Study of Atherosclerosis, and examined the influence of organic produce consumption on this exposure. Methods Individual-level exposure was estimated by combining information on typical intake of specific food items with average OP residue levels on those items. In an analysis restricted to a subset of participants who reported rarely or never eating organic produce (“conventional consumers”), we assessed urinary dialkylphosphate (DAP) levels across tertiles of estimated exposure (n = 480). In a second analysis, we compared DAP levels across subgroups with differing self-reported organic produce consumption habits (n = 240). Results Among conventional consumers, increasing tertile of estimated dietary OP exposure was associated with higher DAP concentrations (p < 0.05). DAP concentrations were also significantly lower in groups reporting more frequent consumption of organic produce (p < 0.02). Conclusions Long-term dietary exposure to OPs was estimated from dietary intake data, and estimates were consistent with DAP measurements. More frequent consumption of organic produce was associated with lower DAPs. Citation Curl CL, Beresford SA, Fenske RA, Fitzpatrick AL, Lu C, Nettleton JA, Kaufman JD. 2015. Estimating pesticide exposure from dietary intake and organic food choices: the Multi-Ethnic Study of Atherosclerosis (MESA). Environ Health Perspect 123:475–483; http://dx.doi.org/10.1289/ehp.1408197 PMID:25650532

Temporary storage or permanent removal? The division of nitrogen between biotic assimilation and denitrification in stormwater biofiltration systems.

PubMed

Payne, Emily G I; Fletcher, Tim D; Russell, Douglas G; Grace, Michael R; Cavagnaro, Timothy R; Evrard, Victor; Deletic, Ana; Hatt, Belinda E; Cook, Perran L M

2014-01-01

The long-term efficacy of stormwater treatment systems requires continuous pollutant removal without substantial re-release. Hence, the division of incoming pollutants between temporary and permanent removal pathways is fundamental. This is pertinent to nitrogen, a critical water body pollutant, which on a broad level may be assimilated by plants or microbes and temporarily stored, or transformed by bacteria to gaseous forms and permanently lost via denitrification. Biofiltration systems have demonstrated effective removal of nitrogen from urban stormwater runoff, but to date studies have been limited to a 'black-box' approach. The lack of understanding on internal nitrogen processes constrains future design and threatens the reliability of long-term system performance. While nitrogen processes have been thoroughly studied in other environments, including wastewater treatment wetlands, biofiltration systems differ fundamentally in design and the composition and hydrology of stormwater inflows, with intermittent inundation and prolonged dry periods. Two mesocosm experiments were conducted to investigate biofilter nitrogen processes using the stable isotope tracer 15NO3(-) (nitrate) over the course of one inflow event. The immediate partitioning of 15NO3(-) between biotic assimilation and denitrification were investigated for a range of different inflow concentrations and plant species. Assimilation was the primary fate for NO3(-) under typical stormwater concentrations (∼1-2 mg N/L), contributing an average 89-99% of 15NO3(-) processing in biofilter columns containing the most effective plant species, while only 0-3% was denitrified and 0-8% remained in the pore water. Denitrification played a greater role for columns containing less effective species, processing up to 8% of 15NO3(-), and increased further with nitrate loading. This study uniquely applied isotope tracing to biofiltration systems and revealed the dominance of assimilation in stormwater biofilters. The findings raise important questions about nitrogen release upon plant senescence, seasonally and in the long term, which have implications on the management and design of biofiltration systems.

Application of a cell-once-through perfusion strategy for production of recombinant antibody from rCHO cells in a Centritech Lab II centrifuge system.

PubMed

Kim, Byoung Jin; Chang, Ho Nam; Oh, Duk Jae

2007-01-01

Based upon the results of scale-down intermittent perfusion processes, a cell-once-through (COT) perfusion concept was applied to a dual bioreactor system coupled to a Centritech Lab II centrifuge for culture of recombinant Chinese hamster ovary (rCHO) cells for monoclonal antibody production. In this new culture mode, i.e., the COT perfusion process, total spent medium was transferred to the centrifuge and a fixed percentage was removed. Approximately 99% of the viable cells are transferred to another bioreactor filled with fresh medium by single operation of the Centritech Lab II centrifuge system for about 30 min. Accordingly, a significant reduction of the cell-passage frequency to the centrifuge led to minimization of cell damage caused by mechanical shear stress, oxygen limitation, nutrient limitation, and low temperature outside the bioreactor. The effects of culture temperature shift and fortified medium on cell growth and recombinant antibody production in the COT perfusion process were investigated. Although the suppressive effects of low culture temperature on cell growth led to a loss of stability in a long-term COT perfusion culture system, the average antibody concentration at 33 degrees C was 157.8 mg/L, approximately 2.4-fold higher than that at 37 degrees C. By the use of a fortified medium at 37 degrees C, rCHO cells were maintained at high density above 1.2 x 10(7) cells/mL, and antibody was produced continuously in a range of 260-280 mg/L in a stable long-term COT perfusion culture. The proposed new culture mode, the COT perfusion approach, guarantees the recovery of rCHO cells damaged by lowered temperature or high lactate and ammonium concentration. It will be an attractive choice for minimization of cell damage and stable long-term antibody production with high cell density.

Comparison of Long-term Care in Nursing Homes Versus Home Health: Costs and Outcomes in Alabama.

PubMed

Blackburn, Justin; Locher, Julie L; Kilgore, Meredith L

2016-04-01

To compare acute care outcomes and costs among nursing home residents with community-dwelling home health recipients. A matched retrospective cohort study of Alabamians aged more than or equal to 65 years admitted to a nursing home or home health between March 31, 2007 and December 31, 2008 (N = 1,291 pairs). Medicare claims were compared up to one year after admission into either setting. Death, emergency department and inpatient visits, inpatient length of stay, and acute care costs were compared using t tests. Medicaid long-term care costs were compared for a subset of matched beneficiaries. After one year, 77.7% of home health beneficiaries were alive compared with 76.2% of nursing home beneficiaries (p < .001). Home health beneficiaries averaged 0.2 hospital visits and 0.1 emergency department visits more than nursing home beneficiaries, differences that were statistically significant. Overall acute care costs were not statistically different; home health beneficiaries' costs averaged $31,423, nursing home beneficiaries' $32,239 (p = .5032). Among 426 dual-eligible pairs, Medicaid long-term care costs averaged $4,582 greater for nursing home residents (p < .001). Using data from Medicare claims, beneficiaries with similar functional status, medical diagnosis history, and demographics had similar acute care costs regardless of whether they were admitted to a nursing home or home health care. Additional research controlling for exogenous factors relating to long-term care decisions is needed. © The Author 2014. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Long-term intake of nuts in relation to cognitive function in older women.

PubMed

O'Brien, J; Okereke, O; Devore, E; Rosner, B; Breteler, M; Grodstein, F

2014-05-01

Nuts contain nutrients that may benefit brain health; thus, we examined long-term intake of nuts in relation to cognition in older women. Population-based prospective cohort study. Academic research using data from the Nurses' Health Study. Nut intake was assessed in a food-frequency questionnaire beginning in1980, and approximately every four years thereafter. Between 1995-2001, 16,010 women age 70 or older (mean age = 74 years) without a history of stroke were administered 4 repeated telephone-based cognitive interviews over 6 years. Our final sample included 15,467 women who completed an initial cognitive interview and had complete information on nut intake. The Telephone Interview for Cognitive Status (TICS), a global score averaging the results of all tests (TICS, immediate and delayed verbal recall, category fluency, and attention), and a verbal memory score averaging the results of tests of verbal recall. In multivariable-adjusted linear regression models, higher long-term total nut intake was associated with better average cognitive status for all cognitive outcomes. For the global composite score combining all tests, women consuming at least 5 servings of nuts/week had higher scores than non-consumers (mean difference=0.08 standard units, 95% confidence interval 0.00-0.15; p-trend=0.003). This mean difference of 0.08 is equivalent to the mean difference we find between women 2 years apart in age. Long-term intake of nuts was not associated with rates of cognitive decline. Higher nut intake may be related to better overall cognition at older ages, and could be an easily-modifiable public health intervention.

Long-term changes in the perception of job characteristics: results from the Belstress II--study.

PubMed

Clays, Els; De Bacquer, Dirk; Leynen, Francoise; Kornitzer, Marcel; Kittel, France; De Backer, Guy

2006-09-01

The aim was to explore long-term changes in the perception of job characteristics--based on the Job Content Questionnaire (JCQ)--in view of the changing labor market in Western societies. A total number of 2,821 workers from nine companies were involved in the longitudinal Belstress-project. Data were gathered on two occasions with a mean time interval of 6.6 yr. At both times, participants completed the JCQ which measures the perception of job demands, job control and social support. In addition, the instrument contains questions regarding physical job demands, job insecurity and impact of world market competition (WMC). Changes over time in the perception of the different dimensions of the JCQ were evaluated within a sample of 2,490 respondents who remained in the same job. A statistically significant long-term stability of all JCQ scales was found. As far as intra-individual changes over time are concerned, the population showed a modest average increase in the perception of job demands, control and support of approximately 3%. Long-term changes in the other scales were larger, with an average increase of 10.3% in job insecurity and 15.5% in impact of WMC. Substantial variation in these two scales was found at the level of the company and in some socio-demographic factors. While perceived job characteristics remained relatively stable over an average period of 6.6 yr, a substantial increase was noted in job insecurity and the impact of WMC. These dimensions are becoming increasingly important within the context of economic globalization and labor market flexibility.

Concentration-response of short-term ozone exposure and hospital admissions for asthma in Texas.

PubMed

Zu, Ke; Liu, Xiaobin; Shi, Liuhua; Tao, Ge; Loftus, Christine T; Lange, Sabine; Goodman, Julie E

2017-07-01

Short-term exposure to ozone has been associated with asthma hospital admissions (HA) and emergency department (ED) visits, but the shape of the concentration-response (C-R) curve is unclear. We conducted a time series analysis of asthma HAs and ambient ozone concentrations in six metropolitan areas in Texas from 2001 to 2013. Using generalized linear regression models, we estimated the effect of daily 8-hour maximum ozone concentrations on asthma HAs for all ages combined, and for those aged 5-14, 15-64, and 65+years. We fit penalized regression splines to evaluate the shape of the C-R curves. Using a log-linear model, estimated risk per 10ppb increase in average daily 8-hour maximum ozone concentrations was highest for children (relative risk [RR]=1.047, 95% confidence interval [CI]: 1.025-1.069), lower for younger adults (RR=1.018, 95% CI: 1.005-1.032), and null for older adults (RR=1.002, 95% CI: 0.981-1.023). However, penalized spline models demonstrated significant nonlinear C-R relationships for all ages combined, children, and younger adults, indicating the existence of thresholds. We did not observe an increased risk of asthma HAs until average daily 8-hour maximum ozone concentrations exceeded approximately 40ppb. Ozone and asthma HAs are significantly associated with each other; susceptibility to ozone is age-dependent, with children at highest risk. C-R relationships between average daily 8-hour maximum ozone concentrations and asthma HAs are significantly curvilinear for all ages combined, children, and younger adults. These nonlinear relationships, as well as the lack of relationship between average daily 8-hour maximum and peak ozone concentrations, have important implications for assessing risks to human health in regulatory settings. Copyright © 2017. Published by Elsevier Ltd.

Variation in urinary spot sample, 24 h samples, and longer-term average urinary concentrations of short-lived environmental chemicals: implications for exposure assessment and reverse dosimetry

PubMed Central

Aylward, Lesa L; Hays, Sean M; Zidek, Angelika

2017-01-01

Population biomonitoring data sets such as the Canadian Health Measures Survey (CHMS) and the United States National Health and Nutrition Examination Survey (NHANES) collect and analyze spot urine samples for analysis for biomarkers of exposure to non-persistent chemicals. Estimation of population intakes using such data sets in a risk-assessment context requires consideration of intra- and inter-individual variability to understand the relationship between variation in the biomarker concentrations and variation in the underlying daily and longer-term intakes. Two intensive data sets with a total of 16 individuals with collection and measurement of serial urine voids over multiple days were used to examine these relationships using methyl paraben, triclosan, bisphenol A (BPA), monoethyl phthalate (MEP), and mono-2-ethylhexyl hydroxyl phthalate (MEHHP) as example compounds. Composited 24 h voids were constructed mathematically from the individual collected voids, and concentrations for each 24 h period and average multiday concentrations were calculated for each individual in the data sets. Geometric mean and 95th percentiles were compared to assess the relationship between distributions in spot sample concentrations and the 24 h and multiday collection averages. In these data sets, spot sample concentrations at the 95th percentile were similar to or slightly higher than the 95th percentile of the distribution of all 24 h composite void concentrations, but tended to overestimate the maximum of the multiday concentration averages for most analytes (usually by less than a factor of 2). These observations can assist in the interpretation of population distributions of spot samples for frequently detected analytes with relatively short elimination half-lives. PMID:27703149

ALTERATIONS IN BRAIN CREATINE CONCENTRATIONS UNDER LONG-TERM SOCIAL ISOLATION (EXPERIMENTAL STUDY).

PubMed

Koshoridze, N; Kuchukashvili, Z; Menabde, K; Lekiashvili, Sh; Koshoridze, M

2016-02-01

Stress represents one of the main problems of modern humanity. This study was done for understanding more clearly alterations in creatine content of the brain under psycho-emotional stress induced by long-term social isolation. It was shown that under 30 days social isolation creatine amount in the brain was arisen, while decreasing concentrations of synthesizing enzymes (AGAT, GAMT) and creatine transporter protein (CrT). Another important point was that such changes were accompanied by down-regulation of creatine kinase (CK), therefore the enzyme's concentration was lowered. In addition, it was observed that content of phosphocreatine (PCr) and ATP were also reduced, thus indicating down-regulation of energy metabolism of brain that is really a crucial point for its normal functioning. To sum up the results it can be underlined that long-term social isolation has negative influence on energy metabolism of brain; and as a result reduce ATP content, while increase of free creatine concentration, supposedly maintaining maximal balance for ATP amount, but here must be also noted that up-regulated oxidative pathways might have impact on blood brain barrier, resulting on its permeability.

National-scale exposure prediction for long-term concentrations of particulate matter and nitrogen dioxide in South Korea.

PubMed

Kim, Sun-Young; Song, Insang

2017-07-01

The limited spatial coverage of the air pollution data available from regulatory air quality monitoring networks hampers national-scale epidemiological studies of air pollution. The present study aimed to develop a national-scale exposure prediction model for estimating annual average concentrations of PM 10 and NO 2 at residences in South Korea using regulatory monitoring data for 2010. Using hourly measurements of PM 10 and NO 2 at 277 regulatory monitoring sites, we calculated the annual average concentrations at each site. We also computed 322 geographic variables in order to represent plausible local and regional pollution sources. Using these data, we developed universal kriging models, including three summary predictors estimated by partial least squares (PLS). The model performance was evaluated with fivefold cross-validation. In sensitivity analyses, we compared our approach with two alternative approaches, which added regional interactions and replaced the PLS predictors with up to ten selected variables. Finally, we predicted the annual average concentrations of PM 10 and NO 2 at 83,463 centroids of residential census output areas in South Korea to investigate the population exposure to these pollutants and to compare the exposure levels between monitored and unmonitored areas. The means of the annual average concentrations of PM 10 and NO 2 for 2010, across regulatory monitoring sites in South Korea, were 51.63 μg/m3 (SD = 8.58) and 25.64 ppb (11.05), respectively. The universal kriging exposure prediction models yielded cross-validated R 2 s of 0.45 and 0.82 for PM 10 and NO 2 , respectively. Compared to our model, the two alternative approaches gave consistent or worse performances. Population exposure levels in unmonitored areas were lower than in monitored areas. This is the first study that focused on developing a national-scale point wise exposure prediction approach in South Korea, which will allow national exposure assessments and epidemiological research to answer policy-related questions and to draw comparisons among different countries. Copyright © 2017 Elsevier Ltd. All rights reserved.

A county-level estimate of PM2.5 related chronic mortality risk in China based on multi-model exposure data.

PubMed

Wang, Qing; Wang, Jiaonan; He, Mike Z; Kinney, Patrick L; Li, Tiantian

2018-01-01

Ambient fine particulate matter (PM 2.5 ) pollution is currently a serious environmental problem in China, but evidence of health effects with higher resolution and spatial coverage is insufficient. This study aims to provide a better overall understanding of long-term mortality effects of PM 2.5 pollution in China and a county-level spatial map for estimating PM 2.5 related premature deaths of the entire country. Using four sets of satellite-derived PM 2.5 concentration data and the integrated exposure-response model which has been employed by the Global Burden of Disease (GBD) to estimate global mortality of ambient and household air pollution in 2010, we estimated PM 2.5 related premature mortality for five endpoints across China in 2010. Premature deaths attributed to PM 2.5 nationwide amounted to 1.27million in total, and 119,167, 83,976, 390,266, 670,906 for adult chronic obstructive pulmonary disease, lung cancer, ischemic heart disease, and stroke, respectively; 3995 deaths for acute lower respiratory infections were estimated in children under the age of 5. About half of the premature deaths were from counties with annual average PM 2.5 concentrations above 63.61μg/m 3 , which cover 16.97% of the Chinese territory. These counties were largely located in the Beijing-Tianjin-Hebei region and the North China Plain. High population density and high pollution areas exhibited the highest health risks attributed to air pollution. On a per capita basis, the highest values were mostly located in heavily polluted industrial regions. PM 2.5 -attributable health risk is closely associated with high population density and high levels of pollution in China. Further estimates using long-term historical exposure data and concentration-response (C-R) relationships should be completed in the future to investigate longer-term trends in the effects of PM 2.5 . Copyright © 2017 Elsevier Ltd. All rights reserved.