Nitro-polycyclic aromatic hydrocarbons - gas-particle partitioning, mass size distribution, and formation along transport in marine and continental background air

NASA Astrophysics Data System (ADS)

Lammel, Gerhard; Mulder, Marie D.; Shahpoury, Pourya; Kukučka, Petr; Lišková, Hana; Přibylová, Petra; Prokeš, Roman; Wotawa, Gerhard

2017-05-01

Nitro-polycyclic aromatic hydrocarbons (NPAH) are ubiquitous in polluted air but little is known about their abundance in background air. NPAHs were studied at one marine and one continental background site, i.e. a coastal site in the southern Aegean Sea (summer 2012) and a site in the central Great Hungarian Plain (summer 2013), together with the parent compounds, PAHs. A Lagrangian particle dispersion model was used to track air mass history. Based on Lagrangian particle statistics, the urban influence on samples was quantified for the first time as a fractional dose to which the collected volume of air had been exposed. At the remote marine site, the 3-4-ring NPAH (sum of 11 targeted species) concentration was 23.7 pg m-3 while the concentration of 4-ring PAHs (6 species) was 426 pg m-3. The most abundant NPAHs were 2-nitrofluoranthene (2NFLT) and 3-nitrophenanthrene. Urban fractional doses in the range of < 0.002-5.4 % were calculated. At the continental site, the Σ11 3-4-ring NPAH and Σ6 4-ring PAH were 58 and 663 pg m-3, respectively, with 9-nitroanthracene and 2NFLT being the most concentrated amongst the targeted NPAHs. The NPAH levels observed in the marine background air are the lowest ever reported and remarkably lower, by more than 1 order of magnitude, than 1 decade before. Day-night variation of NPAHs at the continental site reflected shorter lifetime during the day, possibly because of photolysis of some NPAHs. The yields of formation of 2NFLT and 2-nitropyrene (2NPYR) in marine air seem to be close to the yields for OH-initiated photochemistry observed in laboratory experiments under high NOx conditions. Good agreement is found for the prediction of NPAH gas-particle partitioning using a multi-phase poly-parameter linear free-energy relationship. Sorption to soot is found to be less significant for gas-particle partitioning of NPAHs than for PAHs. The NPAH levels determined in the south-eastern outflow of Europe confirm intercontinental transport

Aircraft and background noise annoyance effects

NASA Technical Reports Server (NTRS)

Willshire, K. F.

1984-01-01

To investigate annoyance of multiple noise sources, two experiments were conducted. The first experiment, which used 48 subjects, was designed to establish annoyance-noise level functions for three community noise sources presented individually: jet aircraft flyovers, air conditioner, and traffic. The second experiment, which used 216 subjects, investigated the effects of background noise on aircraft annoyance as a function of noise level and spectrum shape; and the differences between overall, aircraft, and background noise annoyance. In both experiments, rated annoyance was the dependent measure. Results indicate that the slope of the linear relationship between annoyance and noise level for traffic is significantly different from that of flyover and air conditioner noise and that further research was justified to determine the influence of the two background noises on overall, aircraft, and background noise annoyance (e.g., experiment two). In experiment two, total noise exposure, signal-to-noise ratio, and background source type were found to have effects on all three types of annoyance. Thus, both signal-to-noise ratio, and the background source must be considered when trying to determine community response to combined noise sources.

Effects of background noise on total noise annoyance

NASA Technical Reports Server (NTRS)

Willshire, K. F.

1987-01-01

Two experiments were conducted to assess the effects of combined community noise sources on annoyance. The first experiment baseline relationships between annoyance and noise level for three community noise sources (jet aircraft flyovers, traffic and air conditioners) presented individually. Forty eight subjects evaluated the annoyance of each noise source presented at four different noise levels. Results indicated the slope of the linear relationship between annoyance and noise level for the traffic noise was significantly different from that of aircraft and of air conditioner noise, which had equal slopes. The second experiment investigated annoyance response to combined noise sources, with aircraft noise defined as the major noise source and traffic and air conditioner noise as background noise sources. Effects on annoyance of noise level differences between aircraft and background noise for three total noise levels and for both background noise sources were determined. A total of 216 subjects were required to make either total or source specific annoyance judgements, or a combination of the two, for a wide range of combined noise conditions.

Long term assessment of air quality from a background station on the Malaysian Peninsula.

PubMed

Latif, Mohd Talib; Dominick, Doreena; Ahamad, Fatimah; Khan, Md Firoz; Juneng, Liew; Hamzah, Firdaus Mohamad; Nadzir, Mohd Shahrul Mohd

2014-06-01

Rural background stations provide insight into seasonal variations in pollutant concentrations and allow for comparisons to be made with stations closer to anthropogenic emissions. In Malaysia, the designated background station is located in Jerantut, Pahang. A fifteen-year data set focusing on ten major air pollutants and four meteorological variables from this station were analysed. Diurnal, monthly and yearly pollutant concentrations were derived from hourly continuous monitoring data. Statistical methods employed included principal component regression (PCR) and sensitivity analysis. Although only one of the yearly concentrations of the pollutants studied exceeded national and World Health Organisation (WHO) guideline standards, namely PM10, seven of the pollutants (NO, NO2, NOx, O3, PM10, THC and CH4) showed a positive upward trend over the 15-year period. High concentrations of PM10 were recorded during severe haze episodes in this region. Whilst, monthly concentrations of most air pollutants, such as: PM10, O3, NOx, NO2, CO and NmHC were recorded at higher concentrations between June and September, during the southwest monsoon. Such results correspond with the mid-range transport of pollutants from more urbanised and industrial areas. Diurnal patterns, rationed between major air pollutants and sensitivity analysis, indicate the influence of local traffic emissions on air quality at the Jerantut background station. Although the pollutant concentrations have not shown a rapid increase, an alternative background station will need to be assigned within the next decade if development projects in the surrounding area are not halted. Copyright © 2014 Elsevier B.V. All rights reserved.

Using background air pollutants levels correlation analysis to identify periods of long-range transport of anthropogenic pollution

NASA Astrophysics Data System (ADS)

Konkova, Elizaveta S.; Burtseva, Larisa V.; Gromov, Sergey A.; Gromov, Sergey S.

2017-04-01

Increasing trends of airborne lead and cadmium at background station within the central region of European Russia have been identified previously (e.g., Gromov & Konkova, 2016). In order to reveal the possible drivers of these trends, a deeper investigation of correlation among these heavy metals (HM) and other co-measured pollutants is done in this study. Based on the data for the 2001-2012 period, calculations have been carried out for the period from 2006 onwards, when the growth of HM concentrations is observed. Pairwise correlations of individual species abundances were derived for the entire time series and subsets for each calendar year, including warm (April to September) and cold seasons (October to March). The calculated values for the seasons and the whole years vary substantially, suggesting that that variable ratios of atmospheric HM emission sources could affect the final air concentrations at measurement site in these periods. To distinguish the events of predominant influence of natural and anthropogenic sources, we assume that correlation between lead and cadmium levels must be greater in the case of natural sources being in effect. High values of the correlation coefficient are expected in cases when HM air abundances are induced by the long-range transport from the regions of anthropogenic sources (co-emission of these metals results from a number of same sources, and both of them are also present on same matrix aerosols). The results demonstrate a substantial correlation between Pb and Cd, with higher values for individual seasons (70% of 0.5 and higher) than for whole years. Higher mass concentrations of airborne dust (TSP) in remote areas are to large extent promoted by large particles blown away from the surface at local surroundings. Captured better by filters, such events could be a particular indicator of local (mostly natural) sources. Low or insignificant correlation with HM indicates prevalence of long-range transport of them and could

Background compensation for a radiation level monitor

DOEpatents

Keefe, D.J.

1975-12-01

Background compensation in a device such as a hand and foot monitor is provided by digital means using a scaler. With no radiation level test initiated, a scaler is down-counted from zero according to the background measured. With a radiation level test initiated, the scaler is up-counted from the previous down-count position according to the radiation emitted from the monitored object and an alarm is generated if, with the scaler having crossed zero in the positive going direction, a particular number is exceeded in a specific time period after initiation of the test. If the test is initiated while the scale is down-counting, the background count from the previous down- count stored in a memory is used as the initial starting point for the up-count.

Processing AIRS Scientific Data Through Level 3

NASA Technical Reports Server (NTRS)

Granger, Stephanie; Oliphant, Robert; Manning, Evan

2010-01-01

The Atmospheric Infra-Red Sounder (AIRS) Science Processing System (SPS) is a collection of computer programs, known as product generation executives (PGEs). The AIRS SPS PGEs are used for processing measurements received from the AIRS suite of infrared and microwave instruments orbiting the Earth onboard NASA's Aqua spacecraft. Early stages of the AIRS SPS development were described in a prior NASA Tech Briefs article: Initial Processing of Infrared Spectral Data (NPO-35243), Vol. 28, No. 11 (November 2004), page 39. In summary: Starting from Level 0 (representing raw AIRS data), the AIRS SPS PGEs and the data products they produce are identified by alphanumeric labels (1A, 1B, 2, and 3) representing successive stages or levels of processing. The previous NASA Tech Briefs article described processing through Level 2, the output of which comprises geo-located atmospheric data products such as temperature and humidity profiles among others. The AIRS Level 3 PGE samples selected information from the Level 2 standard products to produce a single global gridded product. One Level 3 product is generated for each day s collection of Level 2 data. In addition, daily Level 3 products are aggregated into two multiday products: an eight-day (half the orbital repeat cycle) product and monthly (calendar month) product.

Air levels of carcinogenic polycyclic aromatic hydrocarbons after the World Trade Center disaster.

PubMed

Pleil, Joachim D; Vette, Alan F; Johnson, Brent A; Rappaport, Stephen M

2004-08-10

The catastrophic collapse of the World Trade Center (WTC) on September 11, 2001, created an immense dust cloud followed by fires that emitted soot into the air of New York City (NYC) well into December. The subsequent cleanup used diesel equipment that further polluted the air until the following June. The particulate air pollutants contained mutagenic and carcinogenic polycyclic aromatic hydrocarbons (PAHs). By using an assay developed for archived samples of fine particles, we measured nine PAHs in 243 samples collected at or near Ground Zero from September 23, 2001, to March 27, 2002. Based on temporal trends of individual PAH levels, we differentiated between fire and diesel sources and predicted PAH levels between 3 and 200 d after the disaster. Predicted PAH air concentrations on September 14, 2001, ranged from 1.3 to 15 ng/m(3); these values are among the highest reported from outdoor sources. We infer that these high initial air concentrations resulted from fires that rapidly diminished over 100 d. Diesel sources predominated for the next 100 d, during which time PAH levels declined slowly to background values. Because elevated PAH levels were transient, any elevation in cancer risk from PAH exposure should be very small among nonoccupationally exposed residents of NYC. However, the high initial levels of PAHs may be associated with reproductive effects observed in the offspring of women who were (or became) pregnant shortly after September 11, 2001. Because no PAH-specific air sampling was conducted, this work provides the only systematic measurements, to our knowledge, of ambient PAHs after the WTC disaster.

Calculating background levels for ecological risk parameters in toxic harbor sediment

USGS Publications Warehouse

Leadon, C.J.; McDonnell, T.R.; Lear, J.; Barclift, D.

2007-01-01

Establishing background levels for biological parameters is necessary in assessing the ecological risks from harbor sediment contaminated with toxic chemicals. For chemicals in sediment, the term contaminated is defined as having concentrations above background and significant human health or ecological risk levels. For biological parameters, a site could be considered contaminated if levels of the parameter are either more or less than the background level, depending on the specific parameter. Biological parameters can include tissue chemical concentrations in ecological receptors, bioassay responses, bioaccumulation levels, and benthic community metrics. Chemical parameters can include sediment concentrations of a variety of potentially toxic chemicals. Indirectly, contaminated harbor sediment can impact shellfish, fish, birds, and marine mammals, and human populations. This paper summarizes the methods used to define background levels for chemical and biological parameters from a survey of ecological risk investigations of marine harbor sediment at California Navy bases. Background levels for regional biological indices used to quantify ecological risks for benthic communities are also described. Generally, background stations are positioned in relatively clean areas exhibiting the same physical and general chemical characteristics as nearby areas with contaminated harbor sediment. The number of background stations and the number of sample replicates per background station depend on the statistical design of the sediment ecological risk investigation, developed through the data quality objective (DQO) process. Biological data from the background stations can be compared to data from a contaminated site by using minimum or maximum background levels or comparative statistics. In Navy ecological risk assessments (ERA's), calculated background levels and appropriate ecological risk screening criteria are used to identify sampling stations and sites with contaminated

Critical assessment of day time traffic noise level at curbside open-air microenvironment of Kolkata City, India.

PubMed

Kundu Chowdhury, Anirban; Debsarkar, Anupam; Chakrabarty, Shibnath

2015-01-01

The objective of the research work is to assess day time traffic noise level at curbside open-air microenvironment of Kolkata city, India under heterogeneous environmental conditions. Prevailing traffic noise level in terms of A-weighted equivalent noise level (Leq) at the microenvironment was in excess of 12.6 ± 2.1 dB(A) from the day time standard of 65 dB(A) for commercial area recommended by the Central Pollution Control Board (CPCB) of India. Noise Climate and Traffic Noise Index of the microenvironment were accounted for 13 ± 1.8 dB(A) and 88.8 ± 6.1 dB(A) respectively. A correlation analysis explored that prevailing traffic noise level of the microenvironment had weak negative (-0.21; p < 0.01) and very weak positive (0.19; p < 0.01) correlation with air temperature and relative humidity. A Varimax rotated principal component analysis explored that motorized traffic volume had moderate positive loading with background noise component (L90, L95, L99) and prevailing traffic noise level had very strong positive loading with peak noise component (L1, L5, L10). Background and peak noise component cumulatively explained 80.98 % of variance in the data set. Traffic noise level at curbside open-air microenvironment of Kolkata City was higher than the standard recommended by CPCB of India. It was highly annoying also. Air temperature and relative humidity had little influence and the peak noise component had the most significant influence on the prevailing traffic noise level at curbside open-air microenvironment. Therefore, traffic noise level at the microenvironment of the city can be reduced with careful honking and driving.

Ground-to-air flow visualization using Solar Calcium-K line Background-Oriented Schlieren

NASA Astrophysics Data System (ADS)

Hill, Michael A.; Haering, Edward A.

2017-01-01

The Calcium-K Eclipse Background-Oriented Schlieren experiment was performed as a proof of concept test to evaluate the effectiveness of using the solar disk as a background to perform the Background-Oriented Schlieren (BOS) method of flow visualization. A ground-based imaging system was equipped with a Calcium-K line optical etalon filter to enable the use of the chromosphere of the sun as the irregular background to be used for BOS. A US Air Force T-38 aircraft performed three supersonic runs which eclipsed the sun as viewed from the imaging system. The images were successfully post-processed using optical flow methods to qualitatively reveal the density gradients in the flow around the aircraft.

Ground Level Ozone Regional Background Characteristics In North-west Pacific Rim

NASA Astrophysics Data System (ADS)

Chiang, C.; Fan, J.; Chang, J. S.

2007-12-01

Understanding the ground level ozone regional background characteristics is essential in understanding the contribution of long-range transport of pollutants from Asia Mainland to air quality in downwind areas. In order to understand this characteristic in north-west Pacific Rim, we conducted a coupled study using ozone observation from regional background stations and 3-D regional-scale chemical transport model simulations. We used O3, CO, wind speed and wind direction data from two regional background stations and ¡§other stations¡¨ over a ten year period and organized several numerical experiments to simulate one spring month in 2003 to obtain a deeper understanding. The so called ¡§other stations¡¨ had actually been named as background stations under various governmental auspices. But we found them to be often under strong influence of local pollution sources with strong diurnal or slightly longer time variations. We found that the Yonagunijima station (24.74 N, 123.02 E) and Heng-Chuen station (21.96 N,120.78 E), about a distance of 400 km apart, have almost the same ozone time series pattern. For these two stations in 2003, correlation coefficients (R2) for annual observed ozone concentration is about 0.64, in the springtime it is about 0.7, and in a one-month period at simulation days it is about 0.76. These two stations have very little small scale variations in all the variables studied. All variations are associated with large scale circulation changes. This is especially so at Yonagunijima station. Using a 3-D regional-scale chemical transport model for East Asia region including contribution from Asia continental outflow and neighboring island pollution areas we found that the Yonagunijima and HengChuen station are indeed free of pollutants from all neighboring areas keeping in mind that pollutants from Taiwan area is never far away. Ozone concentrations in these two stations are dominated by synoptic scale weather patterns, with diffused

Background levels in the Borexino detector

NASA Astrophysics Data System (ADS)

D'Angelo, Davide; Wurm, Michael; Borexino Collaboration

2008-11-01

The Borexino detector, designed and constructed for sub-MeV solar neutrino spectroscopy, is taking data at the Gran Sasso Laboratory, Italy; since May 2007. The main physics objective of Borexino, based on elastic scattering of neutrinos in organic liquid scintillator, is the real time flux measurement of the 862keV mono-energetic neutrinos from 7Be, which set extremely severe radio-purity requirements in the detector's design and handling. The first year of continous data taking provide now evidence of the extremely low background levels achieved in the construction of the detector and in the purification of the target mass. Several pieces of analysis sense the presence of radioisotopes of the 238U and 232Th chains, of 85Kr and of 210Po out of equilibrium from other Radon daughters. Particular emphasis is given to the detection of the cosmic muon background whose angular distributions have been obtained with the outer detector tracking algorithm and to the possibility of tagging the muon-induced neutron background in the scintillator with the recently enhanced electronics setup.

[Algorithm for taking into account the average annual background of air pollution in the assessment of health risks].

PubMed

Fokin, M V

2013-01-01

State Budgetary Educational Institution of Higher Professional Education "I.M. Sechenov First Moscow State Medical University" of the Ministry of Health care and Social Development, Moscow, Russian Federation. The assessment of health risks from air pollution with emissions from industrial facilities, without the average annual background of air pollution does not meet sanitary legislation. However Russian Federal Service for Hydrometeorology and Environmental Monitoring issues official certificates for a limited number of areas covered by the observations of the full program on the stationary points. Questions of accounting average background air pollution in the evaluation of health risks from exposure to emissions from industrial facilities are considered.

Air shower simulation for background estimation in muon tomography of volcanoes

NASA Astrophysics Data System (ADS)

Béné, S.; Boivin, P.; Busato, E.; Cârloganu, C.; Combaret, C.; Dupieux, P.; Fehr, F.; Gay, P.; Labazuy, P.; Laktineh, I.; Lénat, J.-F.; Miallier, D.; Mirabito, L.; Niess, V.; Portal, A.; Vulpescu, B.

2013-01-01

One of the main sources of background for the radiography of volcanoes using atmospheric muons comes from the accidental coincidences produced in the muon telescopes by charged particles belonging to the air shower generated by the primary cosmic ray. In order to quantify this background effect, Monte Carlo simulations of the showers and of the detector are developed by the TOMUVOL collaboration. As a first step, the atmospheric showers were simulated and investigated using two Monte Carlo packages, CORSIKA and GEANT4. We compared the results provided by the two programs for the muonic component of vertical proton-induced showers at three energies: 1, 10 and 100 TeV. We found that the spatial distribution and energy spectrum of the muons were in good agreement for the two codes.

Processing AIRS Scientific Data Through Level 2

NASA Technical Reports Server (NTRS)

Oliphant, Robert; Lee, Sung-Yung; Chahine, Moustafa; Susskind, Joel; arnet, Christopher; McMillin, Larry; Goldberg, Mitchell; Blaisdell, John; Rosenkranz, Philip; Strow, Larrabee

2007-01-01

The Atmospheric Infrared Spectrometer (AIRS) Science Processing System (SPS) is a collection of computer programs, denoted product generation executives (PGEs), for processing the readings of the AIRS suite of infrared and microwave instruments orbiting the Earth aboard NASA s Aqua spacecraft. AIRS SPS at an earlier stage of development was described in "Initial Processing of Infrared Spectral Data' (NPO-35243), NASA Tech Briefs, Vol. 28, No. 11 (November 2004), page 39. To recapitulate: Starting from level 0 (representing raw AIRS data), the PGEs and their data products are denoted by alphanumeric labels (1A, 1B, and 2) that signify the successive stages of processing. The cited prior article described processing through level 1B (the level-2 PGEs were not yet operational). The level-2 PGEs, which are now operational, receive packages of level-1B geolocated radiance data products and produce such geolocated geophysical atmospheric data products such as temperature and humidity profiles. The process of computing these geophysical data products is denoted "retrieval" and is quite complex. The main steps of the process are denoted microwave-only retrieval, cloud detection and cloud clearing, regression, full retrieval, and rapid transmittance algorithm.

Teaching about Natural Background Radiation

ERIC Educational Resources Information Center

Al-Azmi, Darwish; Karunakara, N.; Mustapha, Amidu O.

2013-01-01

Ambient gamma dose rates in air were measured at different locations (indoors and outdoors) to demonstrate the ubiquitous nature of natural background radiation in the environment and to show that levels vary from one location to another, depending on the underlying geology. The effect of a lead shield on a gamma radiation field was also…

“Estimating Regional Background Air Quality using Space/Time Ordinary Kriging to Support Exposure Studies”

EPA Science Inventory

Local-scale dispersion models are increasingly being used to perform exposure assessments. These types of models, while able to characterize local-scale air quality at increasing spatial scale, however, lack the ability to include background concentration in their overall estimat...

Background Noise Analysis in a Few-Photon-Level Qubit Memory

NASA Astrophysics Data System (ADS)

Mittiga, Thomas; Kupchak, Connor; Jordaan, Bertus; Namazi, Mehdi; Nolleke, Christian; Figeroa, Eden

2014-05-01

We have developed an Electromagnetically Induced Transparency based polarization qubit memory. The device is composed of a dual-rail probe field polarization setup colinear with an intense control field to store and retrieve any arbitrary polarization state by addressing a Λ-type energy level scheme in a 87Rb vapor cell. To achieve a signal-to-background ratio at the few photon level sufficient for polarization tomography of the retrieved state, the intense control field is filtered out through an etalon filtrating system. We have developed an analytical model predicting the influence of the signal-to-background ratio on the fidelities and compared it to experimental data. Experimentally measured global fidelities have been found to follow closely the theoretical prediction as signal-to-background decreases. These results suggest the plausibility of employing room temperature memories to store photonic qubits at the single photon level and for future applications in long distance quantum communication schemes.

Using Tropospheric Ozone Profiles and Surface Data (2004 - 2012) to Determine Background Ozone Levels in Houston, Texas

NASA Astrophysics Data System (ADS)

Spychala, M. D.; Morris, G. A.; Lefer, B. L.; Rappenglueck, B.; Cohan, D. S.; zhou, W.

2012-12-01

The Tropospheric Ozone Pollution Project (TOPP) at Rice University (2004 - 2006) and the University of Houston (2006 - present) has gathered > 400 profiles of ozone, temperature, pressure, and relative humidity, and > 250 of those also have wind speed and wind direction near the core of the City of Houston, Texas. Houston continues to be plagued with difficulty in coming into compliance with EPA National Ambient Air Quality Standards (NAAQS) due to a combination of its geographic location, large commuter population, significant petrochemical and energy production, and favorable weather patterns. An outstanding question remains the relative partitioning of ozone between local and remote, anthropogenic and natural sources. In this presentation, we use TOPP ozone profiles to determine a "background" ozone concentration and compare this measure with surface monitor "background" ozone as determined from upwind and downwind Continuous Air Monitoring Stations (CAMS) in an effort to further our understanding of this partitioning. For periods studied with the Community Multiscale Air Quality (CMAQ) Model, we also compare the sonde and surface "background" ozone with that suggested by the model.

Air-surface exchange measurements of gaseous elemental mercury over naturally enriched and background terrestrial landscapes in Australia

NASA Astrophysics Data System (ADS)

Edwards, G. C.; Howard, D. A.

2012-10-01

This paper presents the first gaseous elemental mercury (GEM) air-surface exchange measurements obtained over naturally enriched and background (< 0.1 μg g-1 Hg) terrestrial landscapes in Australia. Two pilot field studies were carried out during the Australian autumn and winter periods at a copper-gold-cobalt-arsenic-mercury mineral field near Pulganbar, NSW. GEM fluxes using a dynamic flux chamber approach were measured, along with controlling environmental parameters over three naturally enriched and three background substrates. The enriched sites results showed net emission to the atmosphere and a strong correlation between flux and substrate Hg concentration, with average fluxes ranging from 14 ± 1 ng m-2 h-1 to 113 ± 6 ng m-2 h-1. Measurements at background sites showed both emission and deposition. The average Hg flux from all background sites showed an overall net emission of 0.36 ± 0.06 ng m-2 h-1. Fluxes show strong relationships with temperature, radiation, and substrate parameters. A compensation point of 2.48, representative of bare soils was determined. Comparison of the Australian data to North American data confirmed the need for Australian specific mercury air-surface exchange data representative of Australia's unique climatic conditions, vegetation types, land use patterns, and soils.

Observations of Europe wide Trends in background and peak O3, CO and NO2 levels

NASA Astrophysics Data System (ADS)

Fleming, Z. L.; Monks, P. S.; Brunsdon, C.; Henne, S.; Buchmann, B.; Konovalov, I.; Beekman, M.

2009-04-01

The GEOMON (Global Earth Observation and MONitoring) project has produced a harmonised data set of trace gases from various ground-based measurement stations. These stations belong to a variety of regional, national and European air quality networks (e.g. EMEP, GAW). Investigations into instrumental calibration and data quality have been carried out in order to make comparison between the sites as accurate as possible for a long time-scale trend analysis. Ozone seasonal cycles at the various sites have been compared, showing characteristic cycles according to latitude, elevation, vicinity to coastal areas and pollution sources and population nearby. A de-trending of this seasonal cycle revealed long-term variations in ozone and a considerable difference between background and peak ozone trends between sites. National, European and international legislation has aimed at reducing CO and NO2 and correspondingly, reduce O3 levels over the last 20 years but the trends are not as clear cut and reveal that there is not a homogeneous reduction in these species across Europe. Splitting the data into seasonal periods and also into lower and upper concentration percentiles shows us more clearly how the species vary across Europe. There is a tendency for peak ozone levels to decrease, whilst the background levels have mostly increased. Averages, lower and upper percentiles of these species at the GEOMON stations are shown on European maps and the distribution of annual ozone trends is evaluated. Comparisons with models that estimate the lower and upper percentiles of ozone during summer overestimate ozone levels but not uniformly across Europe.

Regional and local background ozone in Houston during Texas Air Quality Study 2006

NASA Astrophysics Data System (ADS)

Langford, A. O.; Senff, C. J.; Banta, R. M.; Hardesty, R. M.; Alvarez, R. J.; Sandberg, Scott P.; Darby, Lisa S.

2009-04-01

Principal Component Analysis (PCA) is used to isolate the common modes of behavior in the daily maximum 8-h average ozone mixing ratios measured at 30 Continuous Ambient Monitoring Stations in the Houston-Galveston-Brazoria area during the Second Texas Air Quality Study field intensive (1 August to 15 October 2006). Three principal components suffice to explain 93% of the total variance. Nearly 84% is explained by the first component, which is attributed to changes in the "regional background" determined primarily by the large-scale winds. The second component (6%) is attributed to changes in the "local background," that is, ozone photochemically produced in the Houston area and spatially and temporally averaged by local circulations. Finally, the third component (3.5%) is attributed to short-lived plumes containing high ozone originating from industrial areas along Galveston Bay and the Houston Ship Channel. Regional background ozone concentrations derived using the first component compare well with mean ozone concentrations measured above the Gulf of Mexico by the tunable profiler for aerosols and ozone lidar aboard the NOAA Twin Otter. The PCA regional background values also agree well with background values derived using the lowest daily 8-h maximum method of Nielsen-Gammon et al. (2005), provided the Galveston Airport data (C34) are omitted from that analysis. The differences found when Galveston is included are caused by the sea breeze, which depresses ozone at Galveston relative to sites further inland. PCA removes the effects of this and other local circulations to obtain a regional background value representative of the greater Houston area.

Background contamination by coplanar polychlorinated biphenyls (PCBs) in trace level high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS) analytical procedures.

PubMed

Ferrario, J; Byrne, C; Dupuy, A E

1997-06-01

The addition of the "dioxin-like" polychlorinated biphenyl (PCB) congeners to the assessment of risk associated with the 2,3,7,8-chlorine substituted dioxins and furans has dramatically increased the number of laboratories worldwide that are developing analytical procedures for their detection and quantitation. Most of these procedures are based on established sample preparation and analytical techniques employing high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS), which are used for the analyses of dioxin/furans at low parts-per-trillion (ppt) levels. A significant and widespread problem that arises when using these sample preparation procedures for the analysis of coplanar PCBs is the presence of background levels of these congeners. Industrial processes, urban incineration, leaking electrical transformers, hazardous waste accidents, and improper waste disposal practices have released appreciable quantities of PCBs into the environment. This contamination has resulted in the global distribution of these compounds via the atmosphere and their ubiquitous presence in ambient air. The background presence of these compounds in method blanks must be addressed when determining the exact concentrations of these and other congeners in environmental samples. In this study reliable procedures were developed to accurately define these background levels and assess their variability over the course of the study. The background subtraction procedures developed and employed increase the probability that the values reported accurately represent the concentrations found in the samples and were not biased due to this background contamination.

Background contamination by coplanar polychlorinated biphenyls (PCBs) in trace level high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS) analytical procedures

NASA Technical Reports Server (NTRS)

Ferrario, J.; Byrne, C.; Dupuy, A. E. Jr

1997-01-01

The addition of the "dioxin-like" polychlorinated biphenyl (PCB) congeners to the assessment of risk associated with the 2,3,7,8-chlorine substituted dioxins and furans has dramatically increased the number of laboratories worldwide that are developing analytical procedures for their detection and quantitation. Most of these procedures are based on established sample preparation and analytical techniques employing high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS), which are used for the analyses of dioxin/furans at low parts-per-trillion (ppt) levels. A significant and widespread problem that arises when using these sample preparation procedures for the analysis of coplanar PCBs is the presence of background levels of these congeners. Industrial processes, urban incineration, leaking electrical transformers, hazardous waste accidents, and improper waste disposal practices have released appreciable quantities of PCBs into the environment. This contamination has resulted in the global distribution of these compounds via the atmosphere and their ubiquitous presence in ambient air. The background presence of these compounds in method blanks must be addressed when determining the exact concentrations of these and other congeners in environmental samples. In this study reliable procedures were developed to accurately define these background levels and assess their variability over the course of the study. The background subtraction procedures developed and employed increase the probability that the values reported accurately represent the concentrations found in the samples and were not biased due to this background contamination.

The Influence of Declining Air Lead Levels on Blood Lead-Air Lead Slope Factors in Children

EPA Science Inventory

This presentation describes calculation of blood lead-air lead slope factor within an analysis of the relationship between blood lead levels and air lead levels among participants in the National Health and Nutrition Examination Survey (NHANES). The slope factors are compared wi...

Compliance with the annual NO 2 air quality standard in Athens. Required NO x levels and expected health implications

NASA Astrophysics Data System (ADS)

Chaloulakou, A.; Mavroidis, I.; Gavriil, I.

Recent risk assessment studies have shown that high outdoor NO 2 levels observed in residential areas contribute to increased respiratory and cardiovascular diseases and mortality. Detailed information on present NO 2 levels as well as predictions of NO 2 concentrations corresponding to reduced NO x levels in urban areas are very useful to decision and policy makers in order to protect the public health. In the present paper, monitoring stations of the Athens network are initially classified into two main groups, traffic affected and urban background, using effectively a criterion based on the ratio of annual mean NO:NO 2 concentrations. Two empirical methodologies are then considered and compared for assessing the effect of different NO x levels on the attainment of the annual NO 2 air quality standard at urban-background locations in the Athens area. An interesting finding is that these two methodologies, one more general and one both year and site dependent, give similar results for the specific study area and can be applied alternatively based on the length of available concentration time series. The results show that in order to meet the EU annual mean NO 2 objective at all the urban-background locations of the Athens area, annual NO x concentrations should be reduced to approximately 60 μg m -3, requiring NO x emission reductions of up to 30%. An analysis of the health implications of the currently observed NO 2 levels is conducted, based on a dose-response relationship, and is coupled with available health-related data for the Athens area. This analysis suggests that if NO 2 concentrations were reduced to the levels of the annual EU air quality standard, then a decrease of hospital admissions of up to 2.6% would be observed, depending on the levels of NO 2 measured at different monitoring sites of the Athens conurbation.

The advantages and disadvantages of centralized control of air power at operational level

NASA Astrophysics Data System (ADS)

Arisoy, Uǧur

2014-05-01

People do not want to see and hear a war. In today's world, if war is inevitable, the use of air power is seen as the preferable means of conducting operations instead of financially burdensome land battles which are more likely to cause heavy loss of life. The use of Air Power has gained importance in NATO operations in the Post-Cold War era. For example, air power has undertaken a decisive role from the beginning to the end of the operation in Libya. From this point of view, the most important issue to consider is how to direct air power more effectively at operational level. NATO's Core JFAC (Joint Force Air Command) was established in 2012 to control joint air power at operational level from a single center. US had experienced JFAC aproach in the Operation Desert Storm in 1991. UK, France, Germany, Italy and Spain are also directing their air power from their JFAC structures. Joint air power can be directed from a single center at operational level by means of JFAC. JFAC aproach provides complex planning progress of Air Power to be controled faster in a single center. An Air Power with a large number of aircrafts, long range missiles of cutting-edge technology may have difficulties in achieving results unless directed effectively. In this article, directing air power more effectively at operational level has been studied in the framework of directing air power from a single center carried out by SWOT analysis technique. "Directing Air Power at operational level from a single center similar to JFAC-like structure" is compared with "Directing Air Power at operational level from two centers similar to AC (Air Command) + CAOC (Combined Air Operations Center) structure" As a result of this study, it is assessed that directing air power at operational level from a single center would bring effectiveness to the air campaign. The study examines directing air power at operational level. Developments at political, strategic and tactical levels have been ignored.

The Influence of Declining Air Lead Levels on Blood Lead–Air Lead Slope Factors in Children

PubMed Central

Richmond-Bryant, Jennifer; Davis, Allen; Cohen, Jonathan; Lu, Shou-En; Svendsgaard, David; Brown, James S.; Tuttle, Lauren; Hubbard, Heidi; Rice, Joann; Kirrane, Ellen; Vinikoor-Imler, Lisa C.; Kotchmar, Dennis; Hines, Erin P.; Ross, Mary

2014-01-01

Background: It is difficult to discern the proportion of blood lead (PbB) attributable to ambient air lead (PbA), given the multitude of lead (Pb) sources and pathways of exposure. The PbB–PbA relationship has previously been evaluated across populations. This relationship was a central consideration in the 2008 review of the Pb national ambient air quality standards. Objectives: The objectives of this study were to evaluate the relationship between PbB and PbA concentrations among children nationwide for recent years and to compare the relationship with those obtained from other studies in the literature. Methods: We merged participant-level data for PbB from the National Health and Nutrition Examination Survey (NHANES) III (1988–1994) and NHANES 9908 (1999–2008) with PbA data from the U.S. Environmental Protection Agency. We applied mixed-effects models, and we computed slope factor, d[PbB]/d[PbA] or the change in PbB per unit change in PbA, from the model results to assess the relationship between PbB and PbA. Results: Comparing the NHANES regression results with those from the literature shows that slope factor increased with decreasing PbA among children 0–11 years of age. Conclusion: These findings suggest that a larger relative public health benefit may be derived among children from decreases in PbA at low PbA exposures. Simultaneous declines in Pb from other sources, changes in PbA sampling uncertainties over time largely related to changes in the size distribution of Pb-bearing particulate matter, and limitations regarding sampling size and exposure error may contribute to the variability in slope factor observed across peer-reviewed studies. Citation: Richmond-Bryant J, Meng Q, Davis A, Cohen J, Lu SE, Svendsgaard D, Brown JS, Tuttle L, Hubbard H, Rice J, Kirrane E, Vinikoor-Imler LC, Kotchmar D, Hines EP, Ross M. 2014. The Influence of declining air lead levels on blood lead–air lead slope factors in children. Environ Health Perspect 122:754�

Assessment of indoor and outdoor particulate air pollution at an urban background site in Iran.

PubMed

Mohammadyan, Mahmoud; Ghoochani, Mahboobeh; Kloog, Itai; Abdul-Wahab, Sabah Ahmed; Yetilmezsoy, Kaan; Heibati, Behzad; Godri Pollitt, Krystal J

2017-05-01

The relationship between indoor and outdoor particulate air pollution was investigated at an urban background site on the Payambar Azam Campus of Mazandaran University of Medical Sciences in Sari, Northern Iran. The concentration of particulate matter sized with a diameter less than 1 μm (PM 1.0 ), 2.5 μm (PM 2.5 ), and 10 μm (PM 10 ) was evaluated at 5 outdoor and 12 indoor locations. Indoor sites included classrooms, corridors, and office sites in four university buildings. Outdoor PM concentrations were characterized at five locations around the university campus. Indoor and outdoor PM measurements (1-min resolution) were conducted in parallel during weekday mornings and afternoons. No difference found between indoor PM 10 (50.1 ± 32.1 μg/m 3 ) and outdoor PM 10 concentrations (46.5 ± 26.0 μg/m 3 ), indoor PM 2.5 (22.6 ± 17.4 μg/m 3 ) and outdoor PM 2.5 concentration (22.2 ± 15.4 μg/m 3 ), or indoor PM 1.0 (14.5 ± 13.4 μg/m 3 ) and outdoor mean PM 1.0 concentrations (14.2 ± 12.3 μg/m 3 ). Despite these similar concentrations, no correlations were found between outdoor and indoor PM levels. The present findings are not only of importance for the potential health effects of particulate air pollution on people who spend their daytime over a period of several hours in closed and confined spaces located at a university campus but also can inform regulatory about the improvement of indoor air quality, especially in developing countries.

Global air monitoring study: a multi-country comparison of levels of indoor air pollution in different workplaces.

PubMed

Koong, Heng Nung; Khoo, Deborah; Higbee, Cheryl; Travers, Mark; Hyland, Andrew; Cummings, K Michael; Dresler, Carolyn

2009-03-01

A local study completed in Singapore, which was part of an international multi-country study that aims to develop a global assessment of exposure to second-hand smoke in indoor workplaces, gathered data regarding the indoor air quality of public areas. It was hypothesised that air would be less polluted in non-smoking venues compared to places where smoking occurred. A TSI SidePak AM510 Personal Aerosol Monitor was used to sample and record the levels of respirable suspended particles (RSP) in the air. A broad range of venues were sampled in Singapore. The primary goal of data analysis was to assess the difference in the average levels of RSP in smoke-free and non smoke-free venues. Data was assessed at 3 levels: (a) the mean RSP across all venues sampled compared with the mean levels of smoke-free and non smoke-free venues, (b) levels in venues where smoking occurred compared with similar venues in Ireland, and (c) comparison between smoke-free and non smoke-free areas according to the type of venue. Statistical significance was assessed using the Mann-Whitney U-test. The level of indoor air pollution was 96% lower in smoke-free venues compared to non smoke-free venues. Averaged across each type of venue, the lowest levels of indoor air pollution were found in restaurants (17 microg/m3) and the highest in bars (622 microg/m3); both well above the US EPA Air Quality Index hazardous level of >or=251 ug/m3. This study demonstrates that workers and patrons are exposed to harmful levels of a known carcinogen and toxin. Policies that prohibit smoking in public areas dramatically reduce exposure and improve worker and patron health.

Study of light backgrounds from relativistic electrons in air light-guides

NASA Astrophysics Data System (ADS)

Riordan, S.; Zhao, Y. X.; Baunack, S.; Becker, D.; Clarke, C.; Dehmelt, K.; Deshpande, A.; Gericke, M.; Gläser, B.; Imai, K.; Kutz, T.; Maas, F. E.; McNulty, D.; Pan, J.; Park, S.; Rahman, S.; Souder, P. A.; Wang, P.; Wellman, B.; Kumar, K. S.

2018-07-01

The MOLLER experiment proposed at the Thomas Jefferson National Accelerator Facility plans a precision low energy determination of the weak mixing angle via the measurement of the parity-violating asymmetry in the scattering of high energy longitudinally polarized electrons from electrons bound in a liquid hydrogen target (Møller scattering). A relative measure of the scattering rate is planned to be obtained by intercepting the Møller scattered electrons with a circular array of thin fused silica tiles attached to air light guides, which facilitate the transport of Cherenkov photons generated within the tiles to photomultiplier tubes (PMTs). The scattered flux will also pass through the light guides of downstream tiles, generating additional Cherenkov as well as scintillation light and is a potential background. In order to estimate the rate of these backgrounds, a gas-filled tube detector was designed and deployed in an electron beam at the MAMI facility at Johannes Gutenberg University, Mainz, Germany. Described in this paper is the design of a detector to measure separately the scintillation and Cherenkov responses of gas mixtures from relativistic electrons, the results of studies of several gas mixtures with comparisons to simulations, and conclusions about the implications for the design of the MOLLER detector apparatus.

Air-surface exchange measurements of gaseous elemental mercury over naturally enriched and background terrestrial landscapes in Australia

NASA Astrophysics Data System (ADS)

Edwards, G. C.; Howard, D. A.

2013-05-01

This paper presents the first gaseous elemental mercury (GEM) air-surface exchange measurements obtained over naturally enriched and background (<0.1 μg g-1 Hg) terrestrial landscapes in Australia. Two pilot field studies were carried out during the Australian autumn and winter periods at a copper-gold-cobalt-arsenic-mercury mineral field near Pulganbar, NSW. GEM fluxes using a dynamic flux chamber approach were measured, along with controlling environmental parameters over three naturally enriched and three background substrates. The enriched sites results showed net emission to the atmosphere and a strong correlation between flux and substrate Hg concentration, with average fluxes ranging from 14 ± 1 ng m-2 h-1 to 113 ± 6 ng m-2 h-1. Measurements at background sites showed both emission and deposition. The average Hg flux from all background sites showed an overall net emission of 0.36 ± 0.06 ng m-2 h-1. Fluxes show strong relationships with temperature, radiation, and substrate parameters. A compensation point of 2.48, representative of bare soils was determined. For periods of deposition, dry deposition velocities ranged from 0.00025 cm s-1 to 0.0083 cm s-1 with an average of 0.0041 ± 0.00018 cm s-1, representing bare soil, nighttime conditions. Comparison of the Australian data to North American data suggests the need for Australian-specific mercury air-surface exchange data representative of Australia's unique climatic conditions, vegetation types, land use patterns and soils.

Gestational exposure to urban air pollution related to a decrease in cord blood vitamin d levels.

PubMed

Baïz, Nour; Dargent-Molina, Patricia; Wark, John D; Souberbielle, Jean-Claude; Slama, Rémy; Annesi-Maesano, Isabella

2012-11-01

Vitamin D deficiency has been implicated in the increased risk of several diseases. Exposure to air pollution has been suggested as a contributor to vitamin D deficiency. However, studies that have examined the effects of air pollution on vitamin D status are few and have never focused on prenatal life as an exposure window. Our aim was to investigate the associations between gestational exposure to urban air pollutants and 25-hydroxyvitamin D [25(OH)D] cord blood serum level in 375 mother-child pairs of the EDEN birth cohort. The Atmospheric Dispersion Modelling System (ADMS-Urban) pollution model, a validated dispersion model combining data on traffic conditions, topography, meteorology, and background pollution, was used to assess the concentrations of two major urban pollutants, particulate matter less than 10 μm in diameter (PM(10)) and nitrogen dioxide (NO(2)), at the mother's home address during pregnancy. Cord blood samples were collected at birth and were analyzed for levels of 25(OH)D. Maternal exposure to ambient urban levels of NO(2) and PM(10) during the whole pregnancy was a strong predictor of low vitamin D status in newborns. After adjustment, log-transformed 25(OH)D decreased by 0.15 U (P = 0.05) and 0.41 U (P = 0.04) for a 10-μg/m(3) increase in NO(2) and PM(10) pregnancy levels, respectively. The association was strongest for third-trimester exposures (P = 0.0003 and P = 0.004 for NO(2) and PM(10), respectively). Gestational exposure to ambient urban air pollution, especially during late pregnancy, may contribute to lower vitamin D levels in offspring. This could affect the child's risk of developing diseases later in life.

Microcomputer pollution model for civilian airports and Air Force Bases. Model application and background

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

Segal, H.M.

1988-08-01

This is one of three reports describing the Emissions and Dispersion Modeling System (EDMS). All reports use the same main title--A MICROCOMPUTER MODEL FOR CIVILIAN AIRPORTS AND AIR FORCE BASES--but different subtitles. The subtitles are: (1) USER'S GUIDE - ISSUE 2 (FAA-EE-88-3/ESL-TR-88-54); (2) MODEL DESCRIPTION (FAA-EE-88-4/ESL-TR-88-53); (S) MODEL APPLICATION AND BACKGROUND (FAA-EE-88-5/ESL-TR-88-55). The first and second reports above describe the EDMS model and provide instructions for its use. This is the third report. IT consists of an accumulation of five key documents describing the development and use of the EDMS model. This report is prepared in accordance with discussions withmore » the EPA and requirements outlined in the March 27, 1980 Federal Register for submitting air-quality models to the EPA. Contents: Model Development and Use - Its Chronology and Reports; Monitoring Concorde EMissions; The Influence of Aircraft Operations on Air Quality at Airports; Simplex A - A simplified Atmospheric Dispersion Model for Airport Use -(User's Guide); Microcomputer Graphics in Atmospheric Dispersion Modeling; Pollution from Motor Vehicles and Aircraft at Stapleton International Airport (Abbreviated Report).« less

Measurement of speech levels in the presence of time varying background noise

NASA Technical Reports Server (NTRS)

Pearsons, K. S.; Horonjeff, R.

1982-01-01

Short-term speech level measurements which could be used to note changes in vocal effort in a time varying noise environment were studied. Knowing the changes in speech level would in turn allow prediction of intelligibility in the presence of aircraft flyover noise. Tests indicated that it is possible to use two second samples of speech to estimate long term root mean square speech levels. Other tests were also performed in which people read out loud during aircraft flyover noise. Results of these tests indicate that people do indeed raise their voice during flyovers at a rate of about 3-1/2 dB for each 10 dB increase in background level. This finding is in agreement with other tests of speech levels in the presence of steady state background noise.

Background Indoor Air Concentrations of Volatile Organic Compounds in North American Residences (1990 – 2005): A Compilation of Statistics for Assessing Vapor Intrusion

EPA Pesticide Factsheets

This technical report presents a summary of indoor air studies that measured background concentrations of VOCs in the indoor air of thousands of North American residences and an evaluation and compilation of their reported statistical information.

Siting Background Towers to Characterize Incoming Air for Urban Greenhouse Gas Estimation: A Case Study in the Washington, DC/Baltimore Area

NASA Astrophysics Data System (ADS)

Mueller, K.; Yadav, V.; Lopez-Coto, I.; Karion, A.; Gourdji, S.; Martin, C.; Whetstone, J.

2018-03-01

There is increased interest in understanding urban greenhouse gas (GHG) emissions. To accurately estimate city emissions, the influence of extraurban fluxes must first be removed from urban greenhouse gas (GHG) observations. This is especially true for regions, such as the U.S. Northeastern Corridor-Baltimore/Washington, DC (NEC-B/W), downwind of large fluxes. To help site background towers for the NEC-B/W, we use a coupled Bayesian Information Criteria and geostatistical regression approach to help site four background locations that best explain CO2 variability due to extraurban fluxes modeled at 12 urban towers. The synthetic experiment uses an atmospheric transport and dispersion model coupled with two different flux inventories to create modeled observations and evaluate 15 candidate towers located along the urban domain for February and July 2013. The analysis shows that the average ratios of extraurban inflow to total modeled enhancements at urban towers are 21% to 36% in February and 31% to 43% in July. In July, the incoming air dominates the total variability of synthetic enhancements at the urban towers (R2 = 0.58). Modeled observations from the selected background towers generally capture the variability in the synthetic CO2 enhancements at urban towers (R2 = 0.75, root-mean-square error (RMSE) = 3.64 ppm; R2 = 0.43, RMSE = 4.96 ppm for February and July). However, errors associated with representing background air can be up to 10 ppm for any given observation even with an optimal background tower configuration. More sophisticated methods may be necessary to represent background air to accurately estimate urban GHG emissions.

Interaction between air pollution exposure and genes in relation to levels of inflammatory markers and risk of myocardial infarction

PubMed Central

Panasevich, Sviatlana; Leander, Karin; Ljungman, Petter; Bellander, Tom; de Faire, Ulf; Pershagen, Göran; Nyberg, Fredrik

2013-01-01

Objectives Air pollution exposure induces cardiovascular effects, possibly via systemic inflammation and coagulation misbalance. Genetic variation may determine individual susceptibility. Our aim was to investigate effect modification by inflammation (Interleukin6 (IL6), tumour necrosis factor-α (TNF-α)) and coagulation (fibrinogen Bβ, plasminogen activator inhibitor-1 (PAI-1)) gene variants on the effect of long-term or short-term air pollution exposure on both blood marker levels and non-fatal myocardial infarction (MI) risk. Design Population-based case–control study with a nested case-crossover study. Gene-environment interactions for short-term and long-term air pollution on blood marker levels were studied in population controls, for long-term exposure on MI risk using case–control design, and for short-term exposure on MI onset using case-crossover design. Setting The Stockholm Heart Epidemiology Programme (SHEEP) conducted in 1992–1994 in Stockholm, Sweden. Spatial modelling was used to assess long-term (up to 30 years retrospectively) air pollution exposure to traffic-NO2 and heating-SO2 emissions at home addresses. Urban background NO2, SO2, PM10 and O3 measurements were used to estimate short-term (up to 5 days) air pollution exposure. Participants 1192 MI cases and 1506 population controls aged 45–70 years. Outcomes The levels of blood markers of inflammation (IL-6, TNF-α) and coagulation (fibrinogen, PAI-1) and MI risk. Results We observed gene–environment interaction for several IL6 and TNF SNPs in relation to inflammation blood marker levels. One-year traffic-NO2 exposure was associated with higher IL-6 levels with each additional IL6-174C allele, and 1-year heating-SO2 exposure with higher levels of TNF-α in TNF-308AA homozygotes versus −308G carriers. Short-term air pollution exposure also interacted with IL6 and TNF in relation to marker levels. The risk of MI followed the effect on blood markers in each genotype group

[METHODOLOGY FOR THE ASSESSMENT OF THE IMPACT OF THE ATMOSPHERIC AIR POLLUTION ON THE FORMATION OF THE LEVELS OF OVERALL MORBIDITY RATE OF BRONCHIAL ASTHMA].

PubMed

Veremchuk, L V; Cherpack, N A; Gvozdenko, T A; Volkova, M V

2015-01-01

In large cities with strong air pollution the formation of the levels of morbidity rate of bronchial asthma has a complex causation that requires the search for informative methods for identification of causes and consequences of this dependence. Method for the assessment of the dependence of overall levels of morbidity rate of bronchial asthma on the degree of air pollution allows you to select a "useful information" of the direct impact of air pollution on a background of random processes and latent relationship between human and environment. The use of the method of the information entropy analysis allowed us to estimate the total and the individual contribution of the separate components of air pollution on the formation of levels of total morbidity rate of bronchial asthma in the population of the city of Vladivostok. Levels of total incidence of this pathology were established to differ in various age groups. The adult population is more adapted to air pollution, but retains a high sensitivity to the impact of nitrogen dioxide. Levels of overall l morbidity rate of bronchial asthma in children and adolescents depend on the total air pollution with some dominance of the influence of suspended matter and carbon monoxide.

Air on the Move.

ERIC Educational Resources Information Center

NatureScope, 1985

1985-01-01

Provides (1) background information on global winds, air masses, fronts, and pressure systems; (2) five activities on this topic; and (3) a ready-to-copy coloring page and worksheet. Each activity includes an objective, list of materials needed, recommended age level(s), subject area(s), and instructional strategies. (JN)

Improving Fluency Skills of Secondary-Level Students from Diverse Backgrounds

ERIC Educational Resources Information Center

O'Shea, Doris J.; McQuiston, Kathleen; McCollin, Michelle

2009-01-01

Many secondary-level students from culturally and linguistically diverse (CLD) backgrounds need to nurture their ongoing literacy growth to become independent, tenacious readers. Middle and high school teachers' use of direct and explicit strategies that are focused on culturally and linguistically responsive practices (e.g., use of relevant texts…

Higher fuel prices are associated with lower air pollution levels.

PubMed

Barnett, Adrian G; Knibbs, Luke D

2014-05-01

Air pollution is a persistent problem in urban areas, and traffic emissions are a major cause of poor air quality. Policies to curb pollution levels often involve raising the price of using private vehicles, for example, congestion charges. We were interested in whether higher fuel prices were associated with decreased air pollution levels. We examined an association between diesel and petrol prices and four traffic-related pollutants in Brisbane from 2010 to 2013. We used a regression model and examined pollution levels up to 16 days after the price change. Higher diesel prices were associated with statistically significant short-term reductions in carbon monoxide and nitrogen oxides. Changes in petrol prices had no impact on air pollution. Raising diesel taxes in Australia could be justified as a public health measure. As raising taxes is politically unpopular, an alternative political approach would be to remove schemes that put a downward pressure on fuel prices, such as industry subsidies and shopping vouchers that give fuel discounts. Copyright © 2014 Elsevier Ltd. All rights reserved.

Estimating North American background ozone in U.S. surface air with two independent global models: Variability, uncertainties, and recommendations

EPA Science Inventory

Accurate estimates for North American background (NAB) ozone (O3) in surface air over the United States are needed for setting and implementing an attainable national O3 standard. These estimates rely on simulations with atmospheric chemistry-transport models that set North Amer...

Political factors affecting the enactment of state-level clean indoor air laws.

PubMed

Tung, Gregory Jackson; Vernick, Jon S; Stuart, Elizabeth A; Webster, Daniel W

2014-06-01

We examined the effects of key political institutional factors on the advancement of state-level clean indoor air laws. We performed an observational study of state-level clean indoor air law enactment among all 50 US states from 1993 to 2010 by using extended Cox hazard models to assess risk of enacting a relevant law. During the 18-year period from 1993 to 2010, 28 states passed a law covering workplaces, 33 states passed a law covering restaurants, 29 states passed a law covering bars, and 16 states passed a law covering gaming facilities. States with term limits had a 2.15 times greater hazard (95% confidence interval [CI] = 1.27, 3.65; P = .005) of enacting clean indoor air laws. The presence of state-level preemption of local clean indoor air laws was associated with a 3.26 times greater hazard (95% CI = 1.11, 9.53; P = .031) of state-level policy enactment. In the presence of preemption, increased legislative professionalism was strongly associated (hazard ratio = 3.28; 95% CI = 1.10, 9.75; P = .033) with clean indoor air law enactment. Political institutional factors do influence state-level clean indoor air law enactment and may be relevant to other public health policy areas.

Measurements of Background and Polluted Air in Rural Regions of Rwanda

NASA Astrophysics Data System (ADS)

DeWitt, L.; Gasore, J.; Prinn, R. G.; Potter, K. E.

2015-12-01

Rwanda, a mountainous nation in Equatorial East Africa, is one of the least-urbanized nations in Africa. The majority of the population are subsistence farmers, and major sources of air pollution (e.g., particulates, greenhouse gases) in Rwanda include agricultural burning and cookstoves in rural areas, and older diesel vehicles and mototaxis in cities. Currently, initiatives to supply efficient cookstoves, development of cleaner-burning fuel from recycled agricultural waste, and new regulations on vehicle emissions and importation are underway. These initiatives seek to help Rwanda grow in the greenest way possible, to mitigate negative health and climate effects of development; however, little ambient data on air quality is available in different regions of Rwanda for a baseline study before and benefits study after these initiatives. The Rwanda Climate Observatory, located on the summit of Mt. Mugogo (-1.5833°, 29.5667°), a 2.5 km peak, has recently begun measurements of black carbon (BC) aerosol concentration and O3 and CO gas concentrations. BC measurements were performed with a 7-wavelength Magee Scientific aethalometer and the aethalometer model was used to calculate the influence of fossil fuel and biomass burning sources on BC concentrations. CO and O3 measurements were used in conjunction with BC aerosol data, and HYSPLIT back trajectories were also used to help discriminate between periods of heavy burning and periods of regional influence from traffic and general cookfire emissions. Since Mt. Mugogo is in a rural area, this station captures a snapshot of regional background pollution away from high anthropogenic influence. The nearby households and fields also allow case studies of household and crop burning during localized events and help quanitfy potential daily exposure to particulates and climate-forcing emissions in remote areas of this developing country. We will present time series of the BC, O3, CO and insolation measurements at Mt. Mugogo

Below background levels of blood lead impact cytokine levels in male and female mice

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

Iavicoli, I.; Carelli, G.; Stanek, E.J.

2006-01-15

A number of studies have documented that Pb exerts immunotoxic effects on T lymphocytes. In studies designed to explore this general response over a broad dose range, female Swiss mice were administered six different diets containing Pb acetate 1 day after mating. During lactation, the mothers received the same feed given during pregnancy, and the same diets were administered to the offspring for 9 months after weaning. At the end of exposure, blood Pb level in the offspring was determined, and possible changes in two type 1 cytokines (IL-2, INF-{gamma}) and one type 2 cytokine (IL-4) in the serum weremore » measured. At higher dietary Pb levels (40 and 400 ppm), a significant increase in IL-4 production was associated with a profound decrease in INF-{gamma} and IL-2 production. At the lowest Pb diet level (0.02 ppm), which resulted in a blood lead level of (0.8 {mu}g/dL), which is below background (2-3 {mu}g/dL) values in humans, increases in INF-{gamma} and IL-2 production along with a significant decrease in IL-4 production were observed. The findings provide evidence of a reversal of lead-induced cytokine skewing depending on the blood lead concentration. As blood lead concentration increases, there is a notable skewing toward Th2, while the pattern is reversed favoring Th1 development at lower blood lead values. The present findings are also notable since they indicate the potential for dietary Pb to have significant biological effects below normal background concentrations.« less

Modeling Speech Level as a Function of Background Noise Level and Talker-to-Listener Distance for Talkers Wearing Hearing Protection Devices

ERIC Educational Resources Information Center

Bouserhal, Rachel E.; Bockstael, Annelies; MacDonald, Ewen; Falk, Tiago H.; Voix, Jérémie

2017-01-01

Purpose: Studying the variations in speech levels with changing background noise level and talker-to-listener distance for talkers wearing hearing protection devices (HPDs) can aid in understanding communication in background noise. Method: Speech was recorded using an intra-aural HPD from 12 different talkers at 5 different distances in 3…

Temporal variability of the bioaerosol background at a subway station: concentration level, size distribution, and diversity of airborne bacteria.

PubMed

Dybwad, Marius; Skogan, Gunnar; Blatny, Janet Martha

2014-01-01

Naturally occurring bioaerosol environments may present a challenge to biological detection-identification-monitoring (BIODIM) systems aiming at rapid and reliable warning of bioterrorism incidents. One way to improve the operational performance of BIODIM systems is to increase our understanding of relevant bioaerosol backgrounds. Subway stations are enclosed public environments which may be regarded as potential bioterrorism targets. This study provides novel information concerning the temporal variability of the concentration level, size distribution, and diversity of airborne bacteria in a Norwegian subway station. Three different air samplers were used during a 72-h sampling campaign in February 2011. The results suggested that the airborne bacterial environment was stable between days and seasons, while the intraday variability was found to be substantial, although often following a consistent diurnal pattern. The bacterial levels ranged from not detected to 10(3) CFU m(-3) and generally showed increased levels during the daytime compared to the nighttime levels, as well as during rush hours compared to non-rush hours. The airborne bacterial levels showed rapid temporal variation (up to 270-fold) on some occasions, both consistent and inconsistent with the diurnal profile. Airborne bacterium-containing particles were distributed between different sizes for particles of >1.1 μm, although ∼50% were between 1.1 and 3.3 μm. Anthropogenic activities (mainly passengers) were demonstrated as major sources of airborne bacteria and predominantly contributed 1.1- to 3.3-μm bacterium-containing particles. Our findings contribute to the development of realistic testing and evaluation schemes for BIODIM equipment by providing information that may be used to simulate operational bioaerosol backgrounds during controlled aerosol chamber-based challenge tests with biological threat agents.

Temporal Variability of the Bioaerosol Background at a Subway Station: Concentration Level, Size Distribution, and Diversity of Airborne Bacteria

PubMed Central

Dybwad, Marius; Skogan, Gunnar

2014-01-01

Naturally occurring bioaerosol environments may present a challenge to biological detection-identification-monitoring (BIODIM) systems aiming at rapid and reliable warning of bioterrorism incidents. One way to improve the operational performance of BIODIM systems is to increase our understanding of relevant bioaerosol backgrounds. Subway stations are enclosed public environments which may be regarded as potential bioterrorism targets. This study provides novel information concerning the temporal variability of the concentration level, size distribution, and diversity of airborne bacteria in a Norwegian subway station. Three different air samplers were used during a 72-h sampling campaign in February 2011. The results suggested that the airborne bacterial environment was stable between days and seasons, while the intraday variability was found to be substantial, although often following a consistent diurnal pattern. The bacterial levels ranged from not detected to 103 CFU m−3 and generally showed increased levels during the daytime compared to the nighttime levels, as well as during rush hours compared to non-rush hours. The airborne bacterial levels showed rapid temporal variation (up to 270-fold) on some occasions, both consistent and inconsistent with the diurnal profile. Airborne bacterium-containing particles were distributed between different sizes for particles of >1.1 μm, although ∼50% were between 1.1 and 3.3 μm. Anthropogenic activities (mainly passengers) were demonstrated as major sources of airborne bacteria and predominantly contributed 1.1- to 3.3-μm bacterium-containing particles. Our findings contribute to the development of realistic testing and evaluation schemes for BIODIM equipment by providing information that may be used to simulate operational bioaerosol backgrounds during controlled aerosol chamber-based challenge tests with biological threat agents. PMID:24162566

Air radioactivity levels following the Fukushima reactor accident measured at the Laboratoire Souterrain de Modane, France.

PubMed

Loaiza, P; Brudanin, V; Piquemal, F; Reyss, J-L; Stekl, I; Warot, G; Zampaolo, M

2012-12-01

The radioactivity levels in the air of the radionuclides released by the Fukushima accident were measured at the Laboratoire Souterrain de Modane, in the South-East of France, during the period 25 March-18 April 2011. Air-filters from the ventilation system exposed for one or two days were measured using low-background gamma-ray spectrometry. In this paper we present the activity concentrations obtained for the radionuclides (131)I, (132)Te, (134)Cs, (137)Cs, (95)Nb, (95)Zr, (106)Ru, (140)Ba/La and (103)Ru. The activity concentration of (131)I was of the order of 100 μBq/m(3), more than 100 times higher than the activities of other fission products. The highest activities of (131)I were measured as a first peak on 30 March and a second peak on 3-4 April. The activity concentrations of (134)Cs and (137)Cs varied from 5 to 30 μBq/m(3). The highest activity concentration recorded for Cs corresponded to the same period as for (131)I, with a peak on 2-3 April. The results of the radioactivity concentration levels in grass and mushrooms exposed to the air in the Modane region were also measured. Activity concentrations of (131)I of about 100 mBq/m(2) were found in grass. Copyright © 2012 Elsevier Ltd. All rights reserved.

Background levels of methane in Mars’ atmosphere show strong seasonal variations

NASA Astrophysics Data System (ADS)

Webster, Christopher R.; Mahaffy, Paul R.; Atreya, Sushil K.; Moores, John E.; Flesch, Gregory J.; Malespin, Charles; McKay, Christopher P.; Martinez, German; Smith, Christina L.; Martin-Torres, Javier; Gomez-Elvira, Javier; Zorzano, Maria-Paz; Wong, Michael H.; Trainer, Melissa G.; Steele, Andrew; Archer, Doug; Sutter, Brad; Coll, Patrice J.; Freissinet, Caroline; Meslin, Pierre-Yves; Gough, Raina V.; House, Christopher H.; Pavlov, Alexander; Eigenbrode, Jennifer L.; Glavin, Daniel P.; Pearson, John C.; Keymeulen, Didier; Christensen, Lance E.; Schwenzer, Susanne P.; Navarro-Gonzalez, Rafael; Pla-García, Jorge; Rafkin, Scot C. R.; Vicente-Retortillo, Álvaro; Kahanpää, Henrik; Viudez-Moreiras, Daniel; Smith, Michael D.; Harri, Ari-Matti; Genzer, Maria; Hassler, Donald M.; Lemmon, Mark; Crisp, Joy; Sander, Stanley P.; Zurek, Richard W.; Vasavada, Ashwin R.

2018-06-01

Variable levels of methane in the martian atmosphere have eluded explanation partly because the measurements are not repeatable in time or location. We report in situ measurements at Gale crater made over a 5-year period by the Tunable Laser Spectrometer on the Curiosity rover. The background levels of methane have a mean value 0.41 ± 0.16 parts per billion by volume (ppbv) (95% confidence interval) and exhibit a strong, repeatable seasonal variation (0.24 to 0.65 ppbv). This variation is greater than that predicted from either ultraviolet degradation of impact-delivered organics on the surface or from the annual surface pressure cycle. The large seasonal variation in the background and occurrences of higher temporary spikes (~7 ppbv) are consistent with small localized sources of methane released from martian surface or subsurface reservoirs.

42 CFR 84.140 - Air velocity and noise levels; hoods and helmets; minimum requirements.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 42 Public Health 1 2011-10-01 2011-10-01 false Air velocity and noise levels; hoods and helmets... PROTECTIVE DEVICES Supplied-Air Respirators § 84.140 Air velocity and noise levels; hoods and helmets; minimum requirements. Noise levels generated by the respirator will be measured inside the hood or helmet...

42 CFR 84.140 - Air velocity and noise levels; hoods and helmets; minimum requirements.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 42 Public Health 1 2010-10-01 2010-10-01 false Air velocity and noise levels; hoods and helmets... PROTECTIVE DEVICES Supplied-Air Respirators § 84.140 Air velocity and noise levels; hoods and helmets; minimum requirements. Noise levels generated by the respirator will be measured inside the hood or helmet...

Estimation of exposure to atmospheric pollutants during pregnancy integrating space-time activity and indoor air levels: does it make a difference?

PubMed Central

Marion, OUIDIR; Lise, GIORGIS-ALLEMAND; Sarah, LYON-CAEN; Xavier, MORELLI; Claire, CRACOWSKI; Sabrina, PONTET; Isabelle, PIN; Johanna, LEPEULE; Valérie, SIROUX; Rémy, SLAMA

2016-01-01

Studies of air pollution effects during pregnancy generally only consider exposure in the outdoor air at the home address. We aimed to compare exposure models differing in their ability to account for the spatial resolution of pollutants, space-time activity and indoor air pollution levels. We recruited 40 pregnant women in the Grenoble urban area, France, who carried a Global Positioning System (GPS) during up to 3 weeks; in a subgroup, indoor measurements of fine particles (PM2.5) were conducted at home (n=9) and personal exposure to nitrogen dioxide (NO2) was assessed using passive air samplers (n=10). Outdoor concentrations of NO2, and PM2.5 were estimated from a dispersion model with a fine spatial resolution. Women spent on average 16 h per day at home. Considering only outdoor levels, for estimates at the home address, the correlation between the estimate using the nearest background air monitoring station and the estimate from the dispersion model was high (r=0.93) for PM2.5 and moderate (r=0.67) for NO2. The model incorporating clean GPS data was less correlated with the estimate relying on raw GPS data (r=0.77) than the model ignoring space-time activity (r=0.93). PM2.5 outdoor levels were not to moderately correlated with estimates from the model incorporating indoor measurements and space-time activity (r=−0.10 to 0.47), while NO2 personal levels were not correlated with outdoor levels (r=−0.42 to 0.03). In this urban area, accounting for space-time activity little influenced exposure estimates; in a subgroup of subjects (n=9), incorporating indoor pollution levels seemed to strongly modify them. PMID:26300245

View of Glacier Grey from Lago Grey (Grey Lake), with the Cuernos del Paine mountains in the background, seen during NASA's AirSAR 2004 campaign in Chile

NASA Image and Video Library

2004-03-11

View of Glacier Grey from Lago Grey (Grey Lake), with the Cuernos del Paine mountains in the background, seen during NASA's AirSAR 2004 campaign in Chile. AirSAR 2004 is a three-week expedition in Central and South America by an international team of scientists that is using an all-weather imaging tool, called the Airborne Synthetic Aperture Radar (AirSAR), located onboard NASA's DC-8 airborne laboratory. Scientists from many parts of the world are combining ground research with NASA's AirSAR technology to improve and expand on the quality of research they are able to conduct. Founded in 1959, Torres del Paine National Park encompasses 450,000 acres in the Patagonia region of Chile. This region is being studied by NASA using a DC-8 equipped with an Airborne Synthetic Aperture Radar (AirSAR) developed by scientists from NASA’s Jet Propulsion Laboratory. This is a very sensitive region that is important to scientists because the temperature has been consistently rising causing a subsequent melting of the region’s glaciers. AirSAR will provide a baseline model and unprecedented mapping of the region. This data will make it possible to determine whether the warming trend is slowing, continuing or accelerating. AirSAR will also provide reliable information on ice shelf thickness to measure the contribution of the glaciers to sea level.

A comparison of self reported air pollution problems and GIS-modeled levels of air pollution in people with and without chronic diseases

PubMed Central

Piro, Fredrik Niclas; Madsen, Christian; Næss, Øyvind; Nafstad, Per; Claussen, Bjørgulf

2008-01-01

Objective To explore various contributors to people's reporting of self reported air pollution problems in area of living, including GIS-modeled air pollution, and to investigate whether those with respiratory or other chronic diseases tend to over-report air pollution problems, compared to healthy people. Methods Cross-sectional data from the Oslo Health Study (2000–2001) were linked with GIS-modeled air pollution data from the Norwegian Institute of Air Research. Multivariate regression analyses were performed. 14 294 persons aged 30, 40, 45, 60 or 75 years old with complete information on modeled and self reported air pollution were included. Results People who reported air pollution problems were exposed to significantly higher GIS-modeled air pollution levels than those who did not report such problems. People with chronic disease, reported significantly more air pollution problems after adjustment for modeled levels of nitrogen dioxides, socio-demographic variables, smoking, depression, dwelling conditions and an area deprivation index, even if they had a non-respiratory disease. No diseases, however, were significantly associated with levels of nitrogen dioxides. Conclusion Self reported air pollution problems in area of living are strongly associated with increased levels of GIS-modeled air pollution. Over and above this, those who report to have a chronic disease tend to report more air pollution problems in area of living, despite no significant difference in air pollution exposure compared to healthy people, and no associations between these diseases and NO2. Studies on the association between self reported air pollution problems and health should be aware of the possibility that disease itself may influence the reporting of air pollution. PMID:18307757

Understanding how roadside concentrations of NOx are influenced by the background levels, traffic density, and meteorological conditions using Boosted Regression Trees

NASA Astrophysics Data System (ADS)

Sayegh, Arwa; Tate, James E.; Ropkins, Karl

2016-02-01

Oxides of Nitrogen (NOx) is a major component of photochemical smog and its constituents are considered principal traffic-related pollutants affecting human health. This study investigates the influence of background concentrations of NOx, traffic density, and prevailing meteorological conditions on roadside concentrations of NOx at UK urban, open motorway, and motorway tunnel sites using the statistical approach Boosted Regression Trees (BRT). BRT models have been fitted using hourly concentration, traffic, and meteorological data for each site. The models predict, rank, and visualise the relationship between model variables and roadside NOx concentrations. A strong relationship between roadside NOx and monitored local background concentrations is demonstrated. Relationships between roadside NOx and other model variables have been shown to be strongly influenced by the quality and resolution of background concentrations of NOx, i.e. if it were based on monitored data or modelled prediction. The paper proposes a direct method of using site-specific fundamental diagrams for splitting traffic data into four traffic states: free-flow, busy-flow, congested, and severely congested. Using BRT models, the density of traffic (vehicles per kilometre) was observed to have a proportional influence on the concentrations of roadside NOx, with different fitted regression line slopes for the different traffic states. When other influences are conditioned out, the relationship between roadside concentrations and ambient air temperature suggests NOx concentrations reach a minimum at around 22 °C with high concentrations at low ambient air temperatures which could be associated to restricted atmospheric dispersion and/or to changes in road traffic exhaust emission characteristics at low ambient air temperatures. This paper uses BRT models to study how different critical factors, and their relative importance, influence the variation of roadside NOx concentrations. The paper

PM10 Concentration levels at an urban and background site in Cyprus: The impact of urban sources and dust storms

PubMed Central

Achilleos, Souzana; Evans, John S.; Yiallouros, Panayiotis K.; Kleanthous, Savvas; Schwartz, Joel; Koutrakis, Petros

2016-01-01

Air quality in Cyprus is influenced by both local and transported pollution including desert dust storms. We examined PM10 concentration data collected in Nicosia (urban representative) from April 1, 1993 through December 11, 2008, and Ayia Marina (rural background representative) from January 1, 1999 through December 31, 2008. Measurements were conducted using a Tapered Element Oscillating Micro-balance (TEOM). PM10 concentrations, meteorological records and satellite data were used to identify dust storm days. We investigated long term trends using a Generalized Additive Model (GAM) after controlling for day of week, month, temperature, wind speed, and relative humidity. In Nicosia, annual PM10 concentrations ranged from 50.4 to 63.8 μg/m3 and exceeded the EU annual standard limit enacted in 2005 of 40 μg/m3 every year. A large, statistically significant impact of urban sources (defined as the difference between urban and background levels) was seen in Nicosia over the period 2000–2008, and was highest during traffic hours, weekdays, cold months, and low wind conditions. Our estimate of the mean (standard error) contribution of urban sources to the daily ambient PM10 was 24.0 (0.4) μg/m3. The study of yearly trends showed that PM10 levels in Nicosia decreased from 59.4 μg/m3 in 1993 to 49.0 μg/m3 in 2008, probably in part as a result of traffic emission control policies in Cyprus. In Ayia Marina, annual concentrations ranged from 27.3 to 35.6 μg/m3, and no obvious time trends were observed. The levels measured at the Cyprus background site are comparable to background concentrations reported in other Eastern Mediterranean countries. Average daily PM10 concentrations during desert dust storms were around 100 μg/m3 since 2000 and much higher in earlier years. Despite the large impact of dust storms and their increasing frequency over time, dust storms were responsible for a small fraction of the exceedances of the daily PM10 limit. PMID:25562931

PUBLIC HEALTH AIR SURVEILLANCE EVALUATION (PHASE): BACKGROUND AND AIR QUALITY ASPECT

EPA Science Inventory

NERL's Human Exposure and Atmospheric Sciences Division and other participants in the Public Health Air Surveillance Evaluation (PHASE) project will be discussing their results with the New York State Departments of Health and Environmental Conservation. The PHASE project is a ...

Improving indoor air quality through botanical air filtration in energy efficient residences

NASA Astrophysics Data System (ADS)

Newkirk, Daniel W.

According to the U.S. EPA, the average American spends 90% of their time indoors where pollutants are two to five times more prevalent than outside. The consequences of these pollutants are estimated to cost the U.S. 125 billion dollars in lost health and productivity. Background literature suggests botanical air filtration may be able to solve this problem by leveraging the natural ability of plants to purify indoor air. By improving indoor air quality, energy consumption can also be reduced by bringing in less outside air to dilute contaminants within the space. A botanical air filter, called the Biowall, was designed and grown aeroponically in a sealed environmental chamber. Precise measurements of air temperature, air humidity, air quality and energy consumption were made under various lighting levels, plant species and watering strategies to optimize its performance. It was found to reduce indoor air pollutants 60 percent and has the potential to reduce heating and cooling energy consumption by 20 to 30 percent.

Investigation of background radiation levels and geologic unit profiles in Durango, Colorado

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

Triplett, G.H.; Foutz, W.L.; Lesperance, L.R.

1989-11-01

As part of the Uranium Mill Tailings Remedial Action (UMTRA) Project, Oak Ridge National Laboratory (ORNL) has performed radiological surveys on 435 vicinity properties (VPs) in the Durango area. This study was undertaken to establish the background radiation levels and geologic unit profiles in the Durango VP area. During the months of May through June, 1986, extensive radiometric measurements and surface soil samples were collected in the Durango VP area by personnel from ORNL's Grand Junction Office. A majority of the Durango VP surveys were conducted at sites underlain by Quaternary alluvium, older Quaternary gravels, and Cretaceous Lewis and Mancosmore » shales. These four geologic units were selected to be evaluated. The data indicated no formation anomalies and established regional background radiation levels. Durango background radionuclide concentrations in surface soil were determined to be 20.3 {plus minus} 3.4 pCi/g for {sup 40}K, 1.6 {plus minus} 0.5 pCi/g for {sup 226}Ra, and 1.2 {plus minus} 0.3 pCi/g for {sup 232}Th. The Durango background gamma exposure rate was found to be 16.5 {plus minus} 1.3 {mu}R/h. Average gamma spectral count rate measurements for {sup 40}K, {sup 226}Ra and {sup 232}Th were determined to be 553, 150, and 98 counts per minute (cpm), respectively. Geologic unit profiles and Durango background radiation measurements are presented and compared with other areas. 19 refs., 15 figs., 5 tabs.« less

Background ozone in North China: trends, photochemical and transport impacts

NASA Astrophysics Data System (ADS)

Xu, X.; Lin, W.; Ge, B.

2011-12-01

Tropospheric ozone is one of the key greenhouse gases and plays an important role in atmospheric chemistry. Being a strong oxidant, ozone in the surface layer has significant impacts on human and vegetation health. Long-term measurements of surface ozone are highly needed for climate change assessment and environmental policy-making. Such measurements are scarce, particularly from the background regions. Since 2004, surface ozone and some related reactive gases have been observed at Shangdianzi (SDZ), a Global Atmosphere Watch (GAW) station in North China. Located at the north edge of the Northern China Plain (NCP), the SDZ station is an ideal site for capturing polluted air masses from the NCP sector (southwest) and clean air masses from the background sector (northeast). This facilitates the investigation of impacts of regional transport on surface ozone. In this study, we present long-term measurements of surface ozone made at SDZ, discuss the trends of surface ozone levels in different seasons. Results about the observation-based ozone production efficiency (OPE) for the site will be presented, along with impacts from horizontal and vertical air transport.

Background ozone in North China: trends, photochemical and transport impacts

NASA Astrophysics Data System (ADS)

Xu, X.; Lin, W.; Ge, B.

2012-04-01

Tropospheric ozone is one of the key greenhouse gases and plays an important role in atmospheric chemistry. Being a strong oxidant, ozone in the surface layer has significant impacts on human and vegetation health. Long-term measurements of surface ozone are highly needed for climate change assessment and environmental policy-making. Such measurements are scarce, particularly from the background regions. Since 2004, surface ozone and some related reactive gases have been observed at Shangdianzi (SDZ), a Global Atmosphere Watch (GAW) station in North China. Located at the north edge of the Northern China Plain (NCP), the SDZ station is an ideal site for capturing polluted air masses from the NCP sector (southwest) and clean air masses from the background sector (northeast). This facilitates the investigation of impacts of regional transport on surface ozone. In this study, we present long-term measurements of surface ozone made at SDZ, discuss the trends of surface ozone levels in different seasons. Results about the observation-based ozone production efficiency (OPE) for the site will be presented, along with impacts from horizontal and vertical air transport.

Measurement and reduction of low-level radon background in the KATRIN experiment

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

Fränkle, F. M.

The KArlsruhe TRItium Neutrino (KATRIN) experiment is a next generation, model independent, large scale experiment to determine the mass of the electron anti-neutrino by investigating the kinematics of tritium beta decay with a sensitivity of 200 meV/c{sup 2}. The measurement setup consists of a high luminosity windowless gaseous molecular tritium source (WGTS), a differential and cryogenic pumped electron transport and tritium retention section, a tandem spectrometer section (pre-spectrometer and main spectrometer) for energy analysis, followed by a detector system for counting transmitted beta decay electrons. Measurements performed at the KATRIN pre-spectrometer test setup showed that the decay of radon (Rn)more » atoms in the volume of the KATRIN spectrometers is a major background source. Rn atoms from low-level radon emanation of materials inside the vacuum region of the KATRIN spectrometers are able to penetrate deep into the magnetic flux tube so that the alpha decay of Rn contributes to the background. Of particular importance are electrons emitted in processes accompanying the Rn alpha decay, such as shake-off, internal conversion of excited levels in the Rn daughter atoms and Auger electrons. Lowenergy electrons (< 100 eV) directly contribute to the background in the signal region. High-energy electrons can be stored magnetically inside the volume of the spectrometer and are able to create thousands of secondary electrons via subsequent ionization processes with residual gas molecules. In order to reduce the Rn induced background different active and passive counter measures were developed and tested. This proceeding will give an overview on Rn sources within the KATRIN spectrometer, describes how Rn decays inside the spectrometer produce background events at the detector and presents different counter measures to reduce the Rn induced background.« less

Measurement and reduction of low-level radon background in the KATRIN experiment

NASA Astrophysics Data System (ADS)

Fränkle, F. M.

2013-08-01

The KArlsruhe TRItium Neutrino (KATRIN) experiment is a next generation, model independent, large scale experiment to determine the mass of the electron anti-neutrino by investigating the kinematics of tritium beta decay with a sensitivity of 200 meV/c2. The measurement setup consists of a high luminosity windowless gaseous molecular tritium source (WGTS), a differential and cryogenic pumped electron transport and tritium retention section, a tandem spectrometer section (pre-spectrometer and main spectrometer) for energy analysis, followed by a detector system for counting transmitted beta decay electrons. Measurements performed at the KATRIN pre-spectrometer test setup showed that the decay of radon (Rn) atoms in the volume of the KATRIN spectrometers is a major background source. Rn atoms from low-level radon emanation of materials inside the vacuum region of the KATRIN spectrometers are able to penetrate deep into the magnetic flux tube so that the alpha decay of Rn contributes to the background. Of particular importance are electrons emitted in processes accompanying the Rn alpha decay, such as shake-off, internal conversion of excited levels in the Rn daughter atoms and Auger electrons. Lowenergy electrons (< 100 eV) directly contribute to the background in the signal region. High-energy electrons can be stored magnetically inside the volume of the spectrometer and are able to create thousands of secondary electrons via subsequent ionization processes with residual gas molecules. In order to reduce the Rn induced background different active and passive counter measures were developed and tested. This proceeding will give an overview on Rn sources within the KATRIN spectrometer, describes how Rn decays inside the spectrometer produce background events at the detector and presents different counter measures to reduce the Rn induced background.

Background levels of methane in Mars' atmosphere show strong seasonal variations.

PubMed

Webster, Christopher R; Mahaffy, Paul R; Atreya, Sushil K; Moores, John E; Flesch, Gregory J; Malespin, Charles; McKay, Christopher P; Martinez, German; Smith, Christina L; Martin-Torres, Javier; Gomez-Elvira, Javier; Zorzano, Maria-Paz; Wong, Michael H; Trainer, Melissa G; Steele, Andrew; Archer, Doug; Sutter, Brad; Coll, Patrice J; Freissinet, Caroline; Meslin, Pierre-Yves; Gough, Raina V; House, Christopher H; Pavlov, Alexander; Eigenbrode, Jennifer L; Glavin, Daniel P; Pearson, John C; Keymeulen, Didier; Christensen, Lance E; Schwenzer, Susanne P; Navarro-Gonzalez, Rafael; Pla-García, Jorge; Rafkin, Scot C R; Vicente-Retortillo, Álvaro; Kahanpää, Henrik; Viudez-Moreiras, Daniel; Smith, Michael D; Harri, Ari-Matti; Genzer, Maria; Hassler, Donald M; Lemmon, Mark; Crisp, Joy; Sander, Stanley P; Zurek, Richard W; Vasavada, Ashwin R

2018-06-08

Variable levels of methane in the martian atmosphere have eluded explanation partly because the measurements are not repeatable in time or location. We report in situ measurements at Gale crater made over a 5-year period by the Tunable Laser Spectrometer on the Curiosity rover. The background levels of methane have a mean value 0.41 ± 0.16 parts per billion by volume (ppbv) (95% confidence interval) and exhibit a strong, repeatable seasonal variation (0.24 to 0.65 ppbv). This variation is greater than that predicted from either ultraviolet degradation of impact-delivered organics on the surface or from the annual surface pressure cycle. The large seasonal variation in the background and occurrences of higher temporary spikes (~7 ppbv) are consistent with small localized sources of methane released from martian surface or subsurface reservoirs. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Effect of dry-cleaned clothes on tetrachloroethylene levels in indoor air, personal air, and breath for residents of several New Jersey homes

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

Thomas, K.W.; Pellizzari, E.D.; Perritt, R.L.

1991-10-01

Several volatile organic compounds, including tetrachloroethylene, have been found to be nearly ubiquitous in residential indoor environments during previous TEAM studies. Eleven homes in New Jersey were monitored over three or five days to examine the effect of bringing freshly dry-cleaned clothes into the home on indoor air levels and personal exposures to tetrachloroethylene. Indoor air, personal air, and breath concentrations were measured over multiple 12-hrs periods before and after dry-cleaned clothes were introduced into nine of the homes. No dry-cleaned clothes were introduced into the two remaining homes. Outdoor air tetrachloroethylene concentrations were measured at six of the elevenmore » homes. Indoor/outdoor concentration ratios and source strengths were calculated at the six homes with outdoor measurements. Elevated indoor air levels and human exposures to tetrachloroethylene were measured at seven of the nine homes with dry-cleaned clothes. Indoor air concentrations reached 300 micrograms/m3 in one home and elevated indoor levels persisted for at least 48 hrs in all seven homes. Indoor/outdoor tetrachloroethylene concentration ratios exceeded 100 for the four homes with both dry-cleaned clothes and outdoor measurements. Maximum source strengths ranged from 16 to 69 mg/hr in these homes and did not directly correspond to the number of dry-cleaned garments brought into the home. Breath levels of tetrachloroethylene increased two to six-fold for participants living in seven homes with increased indoor air levels. Indoor air, personal air, and breath tetrachloroethylene concentrations were significantly related (0.05 level) to the number of garments introduced divided by the home volume.« less

Level-1C Product from AIRS: Principal Component Filtering

NASA Technical Reports Server (NTRS)

Manning, Evan M.; Jiang, Yibo; Aumann, Hartmut H.; Elliott, Denis A.; Hannon, Scott

2012-01-01

The Atmospheric Infrared Sounder (AIRS), launched on the EOS Aqua spacecraft on May 4, 2002, is a grating spectrometer with 2378 channels in the range 3.7 to 15.4 microns. In a grating spectrometer each individual radiance measurement is largely independent of all others. Most measurements are extremely accurate and have very low noise levels. However, some channels exhibit high noise levels or other anomalous behavior, complicating applications needing radiances throughout a band, such as cross-calibration with other instruments and regression retrieval algorithms. The AIRS Level-1C product is similar to Level-1B but with instrument artifacts removed. This paper focuses on the "cleaning" portion of Level-1C, which identifies bad radiance values within spectra and produces substitute radiances using redundant information from other channels. The substitution is done in two passes, first with a simple combination of values from neighboring channels, then with principal components. After results of the substitution are shown, differences between principal component reconstructed values and observed radiances are used to investigate detailed noise characteristics and spatial misalignment in other channels.

Measurement of BTEX (benzene, toluene, ethybenzene, and xylene) levels at urban and semirural areas of Algiers City using passive air samplers.

PubMed

Kerchich, Yacine; Kerbachi, Rabah

2012-12-01

The study presents the levels of air pollution by aromatic organic compounds BTEX (benzene, toluene, ethylbenzene, o-, m-, and p-xylenes) in the city of Algiers. The sampling was carried out using Radiello passive sampler. Three sampling campaigns were carried out in roadside, tunnel, urban background, and semirural sites in Algiers. In order to determine the diurnal mean levels of air pollution by BTEX to which people are exposed, a modified passive sampler was used for the first time. In addition, monitoring of pollution inside vehicles was also made. In the spring of 2009, more than 27 samplings were carried out. In the background and road traffic sites the Radiello sampler was exposed for 7 days, whereas the time exposure was reduced to 1 day in the case of the vehicle as well as the tunnel. The results indicate that average benzene concentrations in the roadside and inside vehicle exceed largely the limit value of 5 microg m(-3) established by the European Community (EC). On the other hand, it has been noticed that the concentration levels of other BTEX are relatively high. Also, in order to identify the origin of emission sources, ratios and correlations between the BTEX species have been highlighted. This study shows that road traffic remains the main source of many local emission in Algiers. The vehicle fleet in Algeria is growing rapidly since the 1990s following economic growth and is responsible for the increasing air pollution in large cities. Because there are no data collection of BTEX carried out by national air quality network, all environmental and transportation policies are based on European emissions standards, but national emission standards are currently not in place. This work will contribute to the analysis of real emissions of BTEX in Algiers, for the development of management and for assessment of population exposure variation depending on the location in the city of Algiers.

AIRS pulse tube cooler system-level and in-space performance comparison

NASA Technical Reports Server (NTRS)

Ross, R. G.

2002-01-01

This paper presents the derivation of the test and analysis techniques as well as the measured system-level performance of the flight AIRS coolers during instrument-level, spacecraft-level, and in-space operation.

Stress and physiological, behavioral and performance patterns of children under varied air ion levels

NASA Astrophysics Data System (ADS)

Fornof, K. T.; Gilbert, G. O.

1988-12-01

The possibility that individual differences in reactivity to stressors are a major factor underlying discordant results reported for air ion studies prompted an investigation of response patterns in school children under both normal indoor air ion levels and moderately increased negative air ion levels (4000±500/cm3). It was hypothesized that the impact of stressors is reduced with high negative air ionization, and that resultant changes in stress effects would be differentially exhibited according to the children's normal degree of stimulus reactivity. A counter-balanced, replicative, withinssubject design was selected, and the subjects were 12 environmentally sensitive, 1st 4th grade school children. In addition to monitoring stress effects on activity level, attention span, concentration to task and conceptual performance, measures were also made of urinary 5-hydroxyindole acetic acid levels and skin resistance response (SRR) to determine if changes extended to the physiological state. The cold water test was used to add physical stress and enable calculations of Lacey's autonomic lability scores (ALS) as indicators of individual reactivity. The results show main effects for air ions on both physiological parameters, with 48% less change in %SRR ( P<0.01) and 46% less change in urinary 5-HIAA levels ( P<0.055) during negative air ions, indicating increased stress tolerance. Strong interactive effects for ALS x air ion condition appeared, with high and low ALS children reacting oppositely to negative air ions in measures of skin resistance level ( P<0.01), wrist activity ( P<0.01) and digit span backwards ( P<0.004). Thus individual differences in autonomic reactivity and the presence or absence of stressors appear as critical elements for internal validity, and in preventing consequent skewed results from obscuring progress in air ion research.

Precipitation and Air Temperature Impact on Seasonal Variations of Groundwater Levels

NASA Astrophysics Data System (ADS)

Vitola, Ilva; Vircavs, Valdis; Abramenko, Kaspars; Lauva, Didzis; Veinbergs, Arturs

2012-12-01

The aim of this study is to clarify seasonal effects of precipitation and temperature on groundwater level changes in monitoring stations of the Latvia University of Agriculture - Mellupīte, Bērze and Auce. Groundwater regime and level fluctuations depend on climatic conditions such as precipitation intensity, evapotranspiration, surface runoff and drainage, as well as other hydrological factors. The relationship between precipitation, air temperature and groundwater level fluctuations could also lead and give different perspective of possible changes in groundwater quality. Using mathematical statistics and graphic-analytic methods it is concluded that autumn and winter precipitation has the dominant impact on groundwater level fluctuations, whereas spring and summer season fluctuations are more dependent on the air temperature.

Modelled air pollution levels versus EC air quality legislation - results from high resolution simulation.

PubMed

Chervenkov, Hristo

2013-12-01

An appropriate method for evaluating the air quality of a certain area is to contrast the actual air pollution levels to the critical ones, prescribed in the legislative standards. The application of numerical simulation models for assessing the real air quality status is allowed by the legislation of the European Community (EC). This approach is preferable, especially when the area of interest is relatively big and/or the network of measurement stations is sparse, and the available observational data are scarce, respectively. Such method is very efficient for similar assessment studies due to continuous spatio-temporal coverage of the obtained results. In the study the values of the concentration of the harmful substances sulphur dioxide, (SO2), nitrogen dioxide (NO2), particulate matter - coarse (PM10) and fine (PM2.5) fraction, ozone (O3), carbon monoxide (CO) and ammonia (NH3) in the surface layer obtained from modelling simulations with resolution 10 km on hourly bases are taken to calculate the necessary statistical quantities which are used for comparison with the corresponding critical levels, prescribed in the EC directives. For part of them (PM2.5, CO and NH3) this is done for first time with such resolution. The computational grid covers Bulgaria entirely and some surrounding territories and the calculations are made for every year in the period 1991-2000. The averaged over the whole time slice results can be treated as representative for the air quality situation of the last decade of the former century.

Correlation between low level fluctuations in the x ray background and faint galaxies

NASA Technical Reports Server (NTRS)

Tolstoy, Eline; Griffiths, R. E.

1993-01-01

A correlation between low-level x-ray fluctuations in the cosmic x-ray background flux and the large numbers of galaxies found in deep optical imaging, to m(sub v) is less than or equal to 24 - 26, is desired. These (faint) galaxies by their morphology and color in deep multi-color CCD images and plate material were optically identified. Statistically significant correlations between these galaxies and low-level x-ray fluctuations at the same positions in multiple deep Einstein HRI observations in PAVO and in a ROSAT PSPC field were searched for. Our aim is to test the hypothesis that faint 'star burst' galaxies might contribute significantly to the cosmic x-ray background (at approximately 1 keV).

Lacrimal Cytokines Assessment in Subjects Exposed to Different Levels of Ambient Air Pollution in a Large Metropolitan Area

PubMed Central

Matsuda, Monique; Bonatti, Rodolfo; Marquezini, Mônica V.; Garcia, Maria L. B.; Santos, Ubiratan P.; Braga, Alfésio L. F.; Alves, Milton R.

2015-01-01

Background Air pollution is one of the most environmental health concerns in the world and has serious impact on human health, particularly in the mucous membranes of the respiratory tract and eyes. However, ocular hazardous effects to air pollutants are scarcely found in the literature. Design Panel study to evaluate the effect of different levels of ambient air pollution on lacrimal film cytokine levels of outdoor workers from a large metropolitan area. Methods Thirty healthy male workers, among them nineteen professionals who work on streets (taxi drivers and traffic controllers, high pollutants exposure, Group 1) and eleven workers of a Forest Institute (Group 2, lower pollutants exposure compared to group 1) were evaluated twice, 15 days apart. Exposure to ambient PM2.5 (particulate matter equal or smaller than 2.5 μm) was 24 hour individually collected and the collection of tears was performed to measure interleukins (IL) 2, 4, 5 and 10 and interferon gamma (IFN-γ) levels. Data from both groups were compared using Student’s t test or Mann- Whitney test for cytokines. Individual PM2.5 levels were categorized in tertiles (lower, middle and upper) and compared using one-way ANOVA. Relationship between PM2.5 and cytokine levels was evaluated using generalized estimating equations (GEE). Results PM2.5 levels in the three categories differed significantly (lower: ≤22 μg/m3; middle: 23–37.5 μg/m3; upper: >37.5 μg/m3; p<0.001). The subjects from the two groups were distributed unevenly in the lower category (Group 1 = 8%; Group 2 = 92%), the middle category (Group 1 = 89%; Group 2 = 11%) and the upper category (Group 1 = 100%). A significant relationship was found between IL-5 and IL-10 and PM2.5 levels of the group 1, with an average decrease of 1.65 pg/mL of IL-5 level and of 0.78 pg/mL of IL-10 level in tear samples for each increment of 50 μg/m3 of PM2.5 (p = 0.01 and p = 0.003, respectively). Conclusion High levels of PM2.5 exposure is associated

Air filtration systems and restrictive access conditions improve indoor air quality in clinical units: Penicillium as a general indicator of hospital indoor fungal levels.

PubMed

Araujo, Ricardo; Cabral, João Paulo; Rodrigues, Acácio Gonçalves

2008-03-01

High-efficiency particulate air (HEPA) filters do not completely prevent nosocomial fungal infections. The first aim of this study was to evaluate the impact of different filters and access conditions upon airborne fungi in hospital facilities. Additionally, this study identified fungal indicators of indoor air concentrations. Eighteen rooms and wards equipped with different air filter systems, and access conditions were sampled weekly, during 16 weeks. Tap water samples were simultaneously collected. The overall mean concentration of atmospheric fungi for all wards was 100 colony forming units/m(3). We found a direct proportionality between the levels of the different fungi in the studied atmospheres. Wards with HEPA filters at positive air flow yielded lower fungal levels. Also, the existence of an anteroom and the use of protective clothes were associated to the lowest fungal levels. Principal component analysis showed that penicillia afforded the best separation between wards' air fungal levels. Fungal strains were rarely recovered from tap water samples. In addition to air filtration systems, some access conditions to hospital units, like presence of anteroom and use of protective clothes, may prevent high fungal air load. Penicillia can be used as a general indicator of indoor air fungal levels at Hospital S. João.

[Field investigations of the air pollution level of populated territories].

PubMed

Vinokurov, M V

2014-01-01

The assessment and management of air quality of settlements is one of the priorities in the field of environmental protection. In the management of air quality the backbone factor is the methodology of the organization, performance and interpretation of data of field investigations. The present article is devoted to the analysis of the existing methodological approaches and practical aspects of their application in the organization and performance of field investigations with the aim to confirm the adequacy of the boundaries of the sanitary protection zone in the old industrial regions, hygienic evaluation of the data of field investigations of the air pollution level.

Monitoring of air pollution levels related to Charilaos Trikoupis Bridge.

PubMed

Sarigiannis, D A; Handakas, E J; Kermenidou, M; Zarkadas, I; Gotti, A; Charisiadis, P; Makris, K; Manousakas, M; Eleftheriadis, K; Karakitsios, S P

2017-12-31

Charilaos Trikoupis bridge is the longest cable bridge in Europe that connects Western Greece with the rest of the country. In this study, six air pollution monitoring campaigns (including major regulated air pollutants) were carried out from 2013 to 2015 at both sides of the bridge, located in the urban areas of Rio and Antirrio respectively. Pollution data were statistically analyzed and air quality was characterized using US and European air quality indices. From the overall campaign, it was found that air pollution levels were below the respective regulatory thresholds, but once at the site of Antirrio (26.4 and 52.2μg/m 3 for PM 2.5 and ΡΜ 10 , respectively) during the 2nd winter period. Daily average PM 10 and PM 2.5 levels from two monitoring sites were well correlated to gaseous pollutant (CO, NO, NO 2 , NO x and SO 2 ) levels, meteorological parameters and factor scores from Positive Matrix Factorization during the 3-year period. Moreover, the elemental composition of PM 10 and PM 2.5 was used for source apportionment. That analysis revealed that major emission sources were sulfates, mineral dust, biomass burning, sea salt, traffic and shipping emissions for PM 10 and PM 2.5 , for both Rio and Antirrio. Seasonal variation indicates that sulfates, mineral dust and traffic emissions increased during the warm season of the year, while biomass burning become the dominant during the cold season. Overall, the contribution of the Charilaos Trikoupis bridge to the vicinity air pollution is very low. This is the result of the relatively low daily traffic volume (~10,000 vehicles per day), the respective traffic fleet composition (~81% of the traffic fleet are private vehicles) and the speed limit (80km/h) which does not favor traffic emissions. In addition, the strong and frequent winds further contribute to the rapid dispersion of the emitted pollutants. Copyright © 2017. Published by Elsevier B.V.

PM10 concentration levels at an urban and background site in Cyprus: the impact of urban sources and dust storms.

PubMed

Achilleos, Souzana; Evans, John S; Yiallouros, Panayiotis K; Kleanthous, Savvas; Schwartz, Joel; Koutrakis, Petros

2014-12-01

Air quality in Cyprus is influenced by both local and transported pollution, including desert dust storms. We examined PM10 concentration data collected in Nicosia (urban representative) from April 1, 1993, through December 11, 2008, and in Ayia Marina (rural background representative) from January 1, 1999, through December 31, 2008. Measurements were conducted using a Tapered Element Oscillating Micro-balance (TEOM). PM10 concentrations, meteorological records, and satellite data were used to identify dust storm days. We investigated long-term trends using a Generalized Additive Model (GAM) after controlling for day of week, month, temperature, wind speed, and relative humidity. In Nicosia, annual PM10 concentrations ranged from 50.4 to 63.8 μg/m3 and exceeded the EU annual standard limit enacted in 2005 of 40 μg/m3 every year A large, statistically significant impact of urban sources (defined as the difference between urban and background levels) was seen in Nicosia over the period 2000-2008, and was highest during traffic hours, weekdays, cold months, and low wind conditions. Our estimate of the mean (standard error) contribution of urban sources to the daily ambient PM10 was 24.0 (0.4) μg/m3. The study of yearly trends showed that PM10 levels in Nicosia decreased from 59.4 μg/m3 in 1993 to 49.0 μg/m3 in 2008, probably in part as a result of traffic emission control policies in Cyprus. In Ayia Marina, annual concentrations ranged from 27.3 to 35.6 μg/m3, and no obvious time trends were observed. The levels measured at the Cyprus background site are comparable to background concentrations reported in other Eastern Mediterranean countries. Average daily PM10 concentrations during desert dust storms were around 100 μg/m3 since 2000 and much higher in earlier years. Despite the large impact ofdust storms and their increasing frequency over time, dust storms were responsible for a small fraction of the exceedances of the daily PM10 limit. Implications: This

Control of asthma triggers in indoor air with air cleaners: a modeling analysis

PubMed Central

Myatt, Theodore A; Minegishi, Taeko; Allen, Joseph G; MacIntosh, David L

2008-01-01

Background Reducing exposure to environmental agents indoors shown to increase asthma symptoms or lead to asthma exacerbations is an important component of a strategy to manage asthma for individuals. Numerous investigations have demonstrated that portable air cleaning devices can reduce concentrations of asthma triggers in indoor air; however, their benefits for breathing problems have not always been reproducible. The potential exposure benefits of whole house high efficiency in-duct air cleaners for sensitive subpopulations have yet to be evaluated. Methods We used an indoor air quality modeling system (CONTAM) developed by NIST to examine peak and time-integrated concentrations of common asthma triggers present in indoor air over a year as a function of natural ventilation, portable air cleaners, and forced air ventilation equipped with conventional and high efficiency filtration systems. Emission rates for asthma triggers were based on experimental studies published in the scientific literature. Results Forced air systems with high efficiency filtration were found to provide the best control of asthma triggers: 30–55% lower cat allergen levels, 90–99% lower risk of respiratory infection through the inhalation route of exposure, 90–98% lower environmental tobacco smoke (ETS) levels, and 50–75% lower fungal spore levels than the other ventilation/filtration systems considered. These results indicate that the use of high efficiency in-duct air cleaners provide an effective means of controlling allergen levels not only in a single room, like a portable air cleaner, but the whole house. Conclusion These findings are useful for evaluating potential benefits of high efficiency in-duct filtration systems for controlling exposure to asthma triggers indoors and for the design of trials of environmental interventions intended to evaluate their utility in practice. PMID:18684328

Mitochondrial Genetic Background Modifies the Relationship between Traffic-Related Air Pollution Exposure and Systemic Biomarkers of Inflammation

PubMed Central

Wittkopp, Sharine; Staimer, Norbert; Tjoa, Thomas; Gillen, Daniel; Daher, Nancy; Shafer, Martin; Schauer, James J.; Sioutas, Constantinos; Delfino, Ralph J.

2013-01-01

Background Mitochondria are the main source of reactive oxygen species (ROS). Human mitochondrial haplogroups are linked to differences in ROS production and oxidative-stress induced inflammation that may influence disease pathogenesis, including coronary artery disease (CAD). We previously showed that traffic-related air pollutants were associated with biomarkers of systemic inflammation in a cohort panel of subjects with CAD in the Los Angeles air basin. Objective We tested whether air pollutant exposure-associated inflammation was stronger in mitochondrial haplogroup H than U (high versus low ROS production) in this panel (38 subjects and 417 observations). Methods Inflammation biomarkers were measured weekly in each subject (≤12 weeks), including interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), C-reactive protein, interleukin-6 soluble receptor and tumor necrosis factor-soluble receptor II. We determined haplogroup by restriction fragment length polymorphism analysis. Air pollutants included nitrogen oxides (NOx), carbon monoxide (CO), organic carbon, elemental and black carbon (EC, BC); and particulate matter mass, three size fractions (<0.25 µm, 0.25–2.5 µm, and 2.5–10 µm in aerodynamic diameter). Particulate matter extracts were analyzed for organic compounds, including polycyclic aromatic hydrocarbons (PAH), and in vitro oxidative potential of aqueous extracts. Associations between exposures and biomarkers, stratified by haplogroup, were analyzed by mixed-effects models. Results IL-6 and TNF-α were associated with traffic-related air pollutants (BC, CO, NOx and PAH), and with mass and oxidative potential of quasi-ultrafine particles <0.25 µm. These associations were stronger for haplogroup H than haplogroup U. Conclusions Results suggest that mitochondrial haplogroup U is a novel protective factor for air pollution-related systemic inflammation in this small group of subjects. PMID:23717615

Particulate sulphate and ozone in rural air: Preliminary results from three sites in central England

NASA Astrophysics Data System (ADS)

Martin, A.; Barber, F. R.

Daily particulate sulphate concentrations in air have been measured at a 'background' rural site and at two other sites near rural power stations. The samples were collected by drawing air through filter papers and were analysed by X-ray fluorescence. At the background site the concentration of particulate sulphates was strongly dependent on the O 3 and total S in air. Above a certain 'critical' level of daily O 3, 28% of the daily S in air was particulate on average, but the amounts were not related to the actual O 3 levels. At lower O 3 levels, there appeared to be a constant background of about 2 μg of particulate sulphate per cubic meter of air, together with about 5% of the total S in air as particulate. When black smoke in air was low, the particulate sulphate was also low, despite the O 3 levels. Near the power stations, there was no significantly different rate of production or loss of particulate sulphate. On average, at all three sites over the year, about 12% of the daily total S was particulate, probably corresponding to an average conversion rate of SO 2 of less than 1% per hour. Estimates of hourly particulate sulphates are available from previous measurements at the background site, using a different analysis technique. Particulate sulphate was not found every hour, but typically during 20 h a day in early summer and 8 h a day in early winter. An influence of humidity as well as O 3 was apparent in the peak hourly particulate sulphate values, which reached 60% of the total S. No correlation could be found of particulate sulphate with solar radiation, wind direction, concentrations of oxides of nitrogen in air or ammonium or sulphate in rainwater, but further measurements are planned.

42 CFR 84.202 - Air velocity and noise levels; hoods and helmets; minimum requirements.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 42 Public Health 1 2011-10-01 2011-10-01 false Air velocity and noise levels; hoods and helmets... PROTECTIVE DEVICES Chemical Cartridge Respirators § 84.202 Air velocity and noise levels; hoods and helmets; minimum requirements. Noise levels generated by the respirator will be measured inside the hood or helmet...

42 CFR 84.202 - Air velocity and noise levels; hoods and helmets; minimum requirements.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 42 Public Health 1 2010-10-01 2010-10-01 false Air velocity and noise levels; hoods and helmets... PROTECTIVE DEVICES Chemical Cartridge Respirators § 84.202 Air velocity and noise levels; hoods and helmets; minimum requirements. Noise levels generated by the respirator will be measured inside the hood or helmet...

BOREAS AFM-5 Level-1 Upper Air Network Data

NASA Technical Reports Server (NTRS)

Barr, Alan; Hrynkiw, Charmaine; Newcomer, Jeffrey A. (Editor); Hall, Forrest G. (Editor); Smith, David E. (Technical Monitor)

2000-01-01

The Boreal Ecosystem-Atmosphere Study (BOREAS) Airborne Fluxes and Meteorology (AFM)-5 team collected and processed data from the numerous radiosonde flights during the project. The goals of the AFM-05 team were to provide large-scale definition of the atmosphere by supplementing the existing Atmospheric Environment Service (AES) aerological network, both temporally and spatially. This data set includes basic upper-air parameters collected from the network of upper-air stations during the 1993, 1994, and 1996 field campaigns over the entire study region. The data are contained in tabular ASCII files. The level-1 upper-air network data are available from the Earth Observing System Data and Information System (EOSDIS) Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC). The data files also are available on a CD-ROM (see document number 20010000884).

School Policies and Practices that Improve Indoor Air Quality

ERIC Educational Resources Information Center

Jones, Sherry Everett; Smith, Alisa M.; Wheeler, Lani S.; McManus, Tim

2010-01-01

Background: To determine whether schools with a formal indoor air quality management program were more likely than schools without a formal program to have policies and practices that promote superior indoor air quality. Methods: This study analyzed school-level data from the 2006 School Health Policies and Programs Study, a national study of…

Some insights into the relationship between urban air pollution and noise levels.

PubMed

Kim, Ki-Hyun; Ho, Duy Xuan; Brown, Richard J C; Oh, J-M; Park, Chan Goo; Ryu, In Cheol

2012-05-01

The relationship between noise and air pollution was investigated in eight different districts across Seoul, Korea, between September and November 2010. The noise levels in each district were measured at both roadside and non-roadside locations. It was found that the maximum levels of noise were generally at frequencies of around 1000 Hz. The equivalent noise levels (L(eq)), over all districts, averaged 61.4 ± 7.36 dB which is slightly lower than the noise guidelines set by the World Health Organization (WHO) of 70 dB for industrial, commercial, traffic, and outdoor areas. Comparison of L(eq) levels in each district consistently indicates that noise levels are higher at roadside sites than non-roadside sites. In addition the relative dominance of noise during daytime as compared to nighttime was also apparent. Moreover, the results of an analysis relating sound levels with air pollutant levels indicate strongly that the correlation between these two parameters is the strongest at roadside sites (relative to non-roadside sites) and during nighttime (relative to daytime). The results of our data analysis point to a positive, but complex, correlation between noise levels and air pollution. Copyright © 2012 Elsevier B.V. All rights reserved.

Issues and progress in determining background ozone and particle concentrations

NASA Astrophysics Data System (ADS)

Pinto, J. P.

2011-12-01

Exposure to ambient ozone is associated with a variety of health outcomes ranging from mild breathing discomfort to mortality. For the purpose of health risk and policy assessments EPA evaluates the anthropogenic increase in ozone above background concentrations and has defined the North American (NA) background concentration of O3 as that which would occur in the U.S. in the absence of anthropogenic emissions of precursors in the U.S., Canada, and Mexico. Monthly average NA background ozone has been used to evaluate health risks, but EPA and state air quality managers must also estimate day specific ozone background levels for high ozone episodes as part of urban scale photochemical modeling efforts to support ozone regulatory programs. The background concentration of O3 is of more concern than other air pollutants because it typically represents a much larger fraction of observed O3 than do the backgrounds of other criteria pollutants (particulate matter (PM), CO, NO2, SO2). NA background cannot be determined directly from ambient monitoring data because of the influence of NA precursor emissions on formation of ozone within NA. Instead, estimates of NA background O3 have been based on GEOS-Chem using simulations in which NA anthropogenic precursor emissions are zeroed out. Thus, modeled NA background O3 includes contributions from natural sources of precursors (including CH4, NMVOCs, NOx, and CO) everywhere in the world, anthropogenic sources of precursors outside of NA, and downward transport of O3 from the stratosphere. Although monitoring data cannot determine NA background directly, measurements by satellites, aircraft, ozonesondes and surface monitors have proved to be highly useful for identifying sources of background O3 and for evaluating the performance of the GEOS-Chem model. Model simulated NA background concentrations are strong functions of location and season with large inter-day variability and with values increasing with elevation and higher in

Factors Affecting Parent's Perception on Air Quality-From the Individual to the Community Level.

PubMed

Guo, Yulin; Liu, Fengfeng; Lu, Yuanan; Mao, Zongfu; Lu, Hanson; Wu, Yanyan; Chu, Yuanyuan; Yu, Lichen; Liu, Yisi; Ren, Meng; Li, Na; Chen, Xi; Xiang, Hao

2016-05-12

The perception of air quality significantly affects the acceptance of the public of the government's environmental policies. The aim of this research is to explore the relationship between the perception of the air quality of parents and scientific monitoring data and to analyze the factors that affect parents' perceptions. Scientific data of air quality were obtained from Wuhan's environmental condition reports. One thousand parents were investigated for their knowledge and perception of air quality. Scientific data show that the air quality of Wuhan follows an improving trend in general, while most participants believed that the air quality of Wuhan has deteriorated, which indicates a significant difference between public perception and reality. On the individual level, respondents with an age of 40 or above (40 or above: OR = 3.252; 95% CI: 1.170-9.040), a higher educational level (college and above: OR = 7.598; 95% CI: 2.244-25.732) or children with poor healthy conditions (poor: OR = 6.864; 95% CI: 2.212-21.302) have much more negative perception of air quality. On the community level, industrial facilities, vehicles and city construction have major effects on parents' perception of air quality. Our investigation provides baseline information for environmental policy researchers and makers regarding the public's perception and expectation of air quality and the benefits to the environmental policy completing and enforcing.

Radon as a Source of External Background at Homestake Mine

NASA Astrophysics Data System (ADS)

Thomas, Keenan; Mei, Dongming; Zhang, Chao; Gray, Fred; Gaitskell, Richard; Fiorucci, Simon

2009-05-01

External sources of radioactivity are important concerns for experiments planned for DUSEL at the Homestake Mine in Lead, South Dakota. Radon emanation and deposition is a major threat to the targeted sensitivity of low background experimentation such as double beta decay detection and dark matter searches. Methods to reduce and mitigate these measured levels will need to be developed to prevent experimental signals from contamination through airborne radon decays as well as the deposition of radon daughters. Radon levels were measured at various depths at the Homestake Mine in December of 2008, January and March of 2009. These measurements will be useful in the development of an underground ventilation system to dilute radon concentrations in the air and subsequent systems to provide radon-free air to clean rooms, as well as preparing researchers for the hazards they pose to their experiments. In addition, the measured radon level will be used to understand the radon emanation from different types of rock.

Australia’s first national level quantitative environmental justice assessment of industrial air pollution

NASA Astrophysics Data System (ADS)

Chakraborty, Jayajit; Green, Donna

2014-04-01

This study presents the first national level quantitative environmental justice assessment of industrial air pollution in Australia. Specifically, our analysis links the spatial distribution of sites and emissions associated with industrial pollution sources derived from the National Pollution Inventory, to Indigenous status and social disadvantage characteristics of communities derived from Australian Bureau of Statistics indicators. Our results reveal a clear national pattern of environmental injustice based on the locations of industrial pollution sources, as well as volume, and toxicity of air pollution released at these locations. Communities with the highest number of polluting sites, emission volume, and toxicity-weighted air emissions indicate significantly greater proportions of Indigenous population and higher levels of socio-economic disadvantage. The quantities and toxicities of industrial air pollution are particularly higher in communities with the lowest levels of educational attainment and occupational status. These findings emphasize the need for more detailed analysis in specific regions and communities where socially disadvantaged groups are disproportionately impacted by industrial air pollution. Our empirical findings also underscore the growing necessity to incorporate environmental justice considerations in environmental planning and policy-making in Australia.

Indoor Levels of Formaldehyde and Other Pollutants and Relationship to Air Exchange Rates and Human Activities

NASA Astrophysics Data System (ADS)

Huangfu, Y.; O'Keeffe, P.; Kirk, M.; Walden, V. P.; Lamb, B. K.; Jobson, B. T.

2017-12-01

This paper reports results on an indoor air quality study conducted on six homes in summer and winter, contrasting indoor and outdoor concentrations of O3, CO, CO2, NOx, PM2.5, and selected volatile organic hydrocarbons measured by PTR-MS. Data were collected as 1 minute averages. Air exchange rates of the homes were determined by CO2 tracer release. Smart home sensors, recording human activity level in various places in the home, and window and doors openings, were utilized to better understand the link between human activity and indoor air pollution. From our study, averaged air exchange rates of the homes ranged from 0.2 to 1.2 hour-1 and were greatly affected by the ventilation system type and window and door openings. In general, a negative correlation between air exchange rate and indoor VOCs levels was observed, with large variation of pollutant levels between the homes. For most of the VOCs measured in the house, including formaldehyde and acetaldehyde, summer levels were much higher than winter levels. In some homes formaldehyde levels displayed a time of day variation that was linked to changes in indoor temperature. During a wildfire period in the summer of 2015, outdoor levels of PM2.5, formaldehyde, and benzene dramatically increased, significantly impacting indoor levels due to infiltration. Human activities, such as cooking, can significantly change the levels of most of the compounds measured in the house and the levels can be significantly elevated for short periods of time, with peak levels can be several orders higher compared with typical levels. The data suggest that an outcome of state energy codes that require new homes to be energy efficient, and as a consequence built with lower air exchange rates, will be unacceptable levels of air toxics, notably formaldehyde.

Background differences in baseline and stimulated MMP levels influence abdominal aortic aneurysm susceptibility

PubMed Central

Dale, Matthew A.; Ruhlman, Melissa K.; Zhao, Shijia; Meisinger, Trevor; Gu, Linxia; Swier, Vicki J.; Agrawal, Devendra K.; Greiner, Timothy C.; Carson, Jeffrey S.; Baxter, B. Timothy; Xiong, Wanfen

2015-01-01

Objective Evidence has demonstrated profound influence of genetic background on cardiovascular phenotypes. Murine models in Marfan syndrome (MFS) have shown that genetic background-related variations affect thoracic aortic aneurysm formation, rupture, and lifespan of mice. MFS mice with C57Bl/6 genetic background are less susceptible to aneurysm formation compared to the 129/SvEv genetic background. In this study, we hypothesize that susceptibility to abdominal aortic aneurysm (AAA) will be increased in 129/SvEv mice versus C57Bl/6 mice. We tested this hypothesis by assessing differences in aneurysm size, tissue properties, immune response, and MMP expression. Methods Mice of C57Bl/6 or 129/SvEv background underwent AAA induction by periaortic application of CaCl2. Baseline aortic diameters, tissue properties and MMP levels were measured. After aneurysm induction, diameters, MMP expression, and immune response (macrophage infiltration and bone marrow transplantation) were measured. Results Aneurysms were larger in 129/SvEv mice than C57Bl/6 mice (83.0% ± 13.6 increase compared to 57.8% ± 6.4). The aorta was stiffer in the 129/SvEv mice compared to C57Bl/6 mice (952.5 kPa ± 93.6 versus 621.4 kPa ± 84.2). Baseline MMP-2 and post-aneurysm MMP-2 and -9 levels were higher in 129/SvEv aortas compared to C57Bl/6 aortas. Elastic lamella disruption/fragmentation and macrophage infiltration were increased in 129/SvEv mice. Myelogenous cell reversal by bone marrow transplantation did not affect aneurysm size. Conclusions These data demonstrate that 129/SvEv mice are more susceptible to AAA compared to C57Bl/6 mice. Intrinsic properties of the aorta between the two strains of mice, including baseline expression of MMP-2, influence susceptibility to AAA. PMID:26546710

Effect of background noise on neuronal coding of interaural level difference cues in rat inferior colliculus

PubMed Central

Mokri, Yasamin; Worland, Kate; Ford, Mark; Rajan, Ramesh

2015-01-01

Humans can accurately localize sounds even in unfavourable signal-to-noise conditions. To investigate the neural mechanisms underlying this, we studied the effect of background wide-band noise on neural sensitivity to variations in interaural level difference (ILD), the predominant cue for sound localization in azimuth for high-frequency sounds, at the characteristic frequency of cells in rat inferior colliculus (IC). Binaural noise at high levels generally resulted in suppression of responses (55.8%), but at lower levels resulted in enhancement (34.8%) as well as suppression (30.3%). When recording conditions permitted, we then examined if any binaural noise effects were related to selective noise effects at each of the two ears, which we interpreted in light of well-known differences in input type (excitation and inhibition) from each ear shaping particular forms of ILD sensitivity in the IC. At high signal-to-noise ratios (SNR), in most ILD functions (41%), the effect of background noise appeared to be due to effects on inputs from both ears, while for a large percentage (35.8%) appeared to be accounted for by effects on excitatory input. However, as SNR decreased, change in excitation became the dominant contributor to the change due to binaural background noise (63.6%). These novel findings shed light on the IC neural mechanisms for sound localization in the presence of continuous background noise. They also suggest that some effects of background noise on encoding of sound location reported to be emergent in upstream auditory areas can also be observed at the level of the midbrain. PMID:25865218

Air pollution exposure--a trigger for myocardial infarction?

PubMed

Berglind, Niklas; Ljungman, Petter; Möller, Jette; Hallqvist, Johan; Nyberg, Fredrik; Rosenqvist, Mårten; Pershagen, Göran; Bellander, Tom

2010-04-01

The association between ambient air pollution exposure and hospitalization for cardiovascular events has been reported in several studies with conflicting results. A case-crossover design was used to investigate the effects of air pollution in 660 first-time myocardial infarction cases in Stockholm in 1993-1994, interviewed shortly after diagnosis using a standard protocol. Air pollution data came from central urban background monitors. No associations were observed between the risk for onset of myocardial infarction and two-hour or 24-hour air pollution exposure. No evidence of susceptible subgroups was found. This study provides no support that moderately elevated air pollution levels trigger first-time myocardial infarction.

AirMSPI Level 2 V001 New Data for NASA's ORACLES Campaign

Atmospheric Science Data Center

2018-05-07

AirMSPI Level 2 V001 New Data for NASA's ORACLES Campaign Friday, February 2, 2018 The NASA Langley Atmospheric Sciences Data Center (ASDC) and Jet Propulsion ... ) flight campaign.   AirMSPI flies in the nose of NASA's high-altitude ER-2 aircraft. The instrument was built by JPL and the ...

Background culturable bacteria aerosol in two large public buildings using HVAC filters as long term, passive, high-volume air samplers.

PubMed

Stanley, Nicholas J; Kuehn, Thomas H; Kim, Seung Won; Raynor, Peter C; Anantharaman, Senthilvelan; Ramakrishnan, M A; Goyal, Sagar M

2008-04-01

Background culturable bacteria aerosols were collected and identified in two large public buildings located in Minneapolis, Minnesota and Seattle, Washington over a period of 5 months and 3 months, respectively. The installed particulate air filters in the ventilation systems were used as the aerosol sampling devices at each location. Both pre and final filters were collected from four air handing units at each site to determine the influence of location within the building, time of year, geographical location and difference between indoor and outdoor air. Sections of each loaded filter were eluted with 10 ml of phosphate buffered saline (PBS). The resulting solutions were cultured on blood agar plates and incubated for 24 h at 36 degrees C. Various types of growth media were then used for subculturing, followed by categorization using a BioLog MicroStation (Biolog, Hayward, CA, USA) and manual observation. Environmental parameters were gathered near each filter by the embedded on-site environmental monitoring systems to determine the effect of temperature, humidity and air flow. Thirty nine different species of bacteria were identified, 17 found only in Minneapolis and 5 only in Seattle. The hardy spore-forming genus Bacillus was the most commonly identified and showed the highest concentrations. A significant decrease in the number of species and their concentration occurred in the Minneapolis air handling unit supplying 100% outdoor air in winter, however no significant correlations between bacteria concentration and environmental parameters were found.

Concentrations, sources and human health risk of inhalation exposure to air toxics in Edmonton, Canada.

PubMed

Bari, Md Aynul; Kindzierski, Warren B

2017-04-01

With concern about levels of air pollutants in recent years in the Capital Region of Alberta, an investigation of ambient concentrations, sources and potential human health risk of hazardous air pollutants (HAPs) or air toxics was undertaken in the City of Edmonton over a 5-year period (2009-2013). Mean concentrations of individual HAPs in ambient air including volatile organic compounds (VOCs), polycyclic aromatic hydrocarbons (PAHs) and trace metals ranged from 0.04 to 1.73 μg/m 3 , 0.01-0.54 ng/m 3 , and 0.05-3.58 ng/m 3 , respectively. Concentrations of benzene, naphthalene, benzo(a)pyrene (BaP), arsenic, manganese and nickel were far below respective annual Alberta Ambient Air Quality Objectives. Carcinogenic and non-carcinogenic risk of air toxics were also compared with risk levels recommended by regulatory agencies. Positive matrix factorization identified six air toxics sources with traffic as the dominant contributor to total HAPs (4.33 μg/m 3 , 42%), followed by background/secondary organic aerosol (SOA) (1.92 μg/m 3 , 25%), fossil fuel combustion (0.92 μg/m 3 , 11%). On high particulate air pollution event days, local traffic was identified as the major contributor to total HAPs compared to background/SOA and fossil fuel combustion. Carcinogenic risk values of traffic, background/SOA and metals industry emissions were above the USEPA acceptable level (1 × 10 -6 ), but below a tolerable risk (1 × 10 -4 ) and Alberta benchmark (1 × 10 -5 ). These findings offer useful preliminary information about current ambient air toxics levels, dominant sources and their potential risk to public health; and this information can support policy makers in the development of appropriate control strategies if required. Copyright © 2017 Elsevier Ltd. All rights reserved.

Critical level setting of continuous air monitor.

PubMed

Li, Huibin; Jia, Mingyan; Wang, Kailiang

2013-01-01

Algorithms used to compensate the radon and thoron progeny's interference are one of the key technologies for continuous air monitors (CAMs). In this study, a CAM that can automatically change filter was manufactured, and equations used to calculate the transuranic aerosol concentration and the corresponding critical level were derived. The parameters used in calculation were acquired by continuous measurement in a high radon environment. At last, validation of the calculation was tested in a cave where the radon concentration fluctuated frequently, and the results were analysed.

The effects of transboundary air pollution following major events in China on air quality in the U.S.: Evidence from Chinese New Year and sandstorms.

PubMed

Ngo, N S; Zhong, N; Bao, X

2018-04-15

Transboundary air pollution is a global environmental and public health problem including in the U.S., where pollution emissions from China, the largest emitter of anthropogenic air pollution in the world, can travel across the Pacific Ocean and reach places like California and Oregon. We examine the effects of transboundary air pollution following major events in China, specifically sandstorms, a natural-occurring source of air pollution, and Chinese New Year, a major 7-day holiday, on background air quality in the U.S. We focus on high elevation sites on the west coast between 2000 and 2013. We use regression analysis and a natural experiment to exploit the variation in the timing of these events in China, which are plausibly uncorrelated to other factors that affect air quality in China and the U.S. We find that sandstorms are associated with statistically significant increases in background coarse and fine particulate matter (PM) in the U.S., representing between 16 and 39% of average weekly PM levels. We also find Chinese New Year is associated with modest reductions in background air quality in the U.S., representing between 0.4 and 2.5% of PM levels. Findings are robust to different models and falsification tests. These results suggest that regression analysis could be a powerful tool to complement other, more widely used techniques in the environmental sciences that study this problem. This also has important implications for policymakers, who could track major sandstorms in China and prepare for possible increased foreign pollution emissions in the U.S. Copyright © 2018 Elsevier Ltd. All rights reserved.

Proposed methodology for estimating the impact of highway improvements on urban air pollution.

DOT National Transportation Integrated Search

1971-01-01

The aim of this methodology is to indicate the expected change in ambient air quality in the vicinity of a highway improvement and in the total background level of urban air pollution resulting from the highway improvement. Both the jurisdiction in w...

Correlations between health status and OralChroma™-determined volatile sulfide levels in mouth air of the elderly.

PubMed

Awano, Shuji; Takata, Yutaka; Soh, Inho; Yoshida, Akihiro; Hamasaki, Tomoko; Sonoki, Kazuo; Ohsumi, Tomoko; Nishihara, Tatsuji; Ansai, Toshihiro

2011-12-01

Dimethyl sulfide (DMS), a volatile sulfur compound (VSC) found in mouth air, is thought to be associated with systemic diseases; this in contrast to the two other VSCs found in mouth air: hydrogen sulfide and methyl mercaptan (MM). This study aimed to validate the relationship between DMS in mouth air and oral and systemic factors. The subjects were 393 elderly Japanese volunteers participating in an oral and systemic health survey. They were surveyed for the concentration of VSC components in their mouth air and for their oral and systemic health status. Using logistic regression models, the prevalence of DMS in mouth air above the organoleptic threshold level (OTL) was found to be significantly associated with high-density lipoprotein (HDL) cholesterol level, medical history of colon polyps and asthma, being female, and the presence of MM in mouth air above the OTL. Our data suggest that systemic factors, such as a high serum HDL cholesterol level and a medical history of asthma and colon polyps, might be more prominent in subjects with elevated DMS. The differences, although statistically significant, are quite small. They also indicate that an oral factor, such as a high MM mouth-air level also influences the DMS mouth-air level in addition to systemic factors.

Effects of the Bermuda High and the Great Plains low-level jet upon background and peak ozone concentrations in Texas urban areas

NASA Astrophysics Data System (ADS)

Estes, M. J.; Wang, Y.; Lei, R.; Wang, S. C.; Jia, B.

2017-12-01

Previous studies have established that the westward extent of the Bermuda High is strongly linked to the ozone concentrations in Houston. This study examines the linkages between the Bermuda High, the Great Plains low-level jet, background ozone in the eastern half of Texas, and local contributions to peak ozone in Texas urban areas. Analysis of North American Regional Reanalysis (NARR) wind and pressure fields will be used to establish the presence and strength of synoptic-scale weather features, and this information will be used with ozone data from air quality networks to determine the effects upon the seasonal and interannual variations of ozone. Quantification of the effects of large-scale meteorological factors will improve understanding of the causes of ozone variations, including decadal trends in Texas cities.

Design and implementation of an air monitoring program in support of a brownfields redevelopment program

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

Maisel, B.E.; Hunt, G.T.; Devaney, R.J. Jr.

EPA`s Brownfields Economic Redevelopment Initiative has sparked renewal of industrial and commercial parcels otherwise idled or under-utilized because of real or perceived environmental contamination. In certain cases, restoring such parcels to productive economic use requires a redevelopment effort protective of human health and welfare through minimizing offsite migration of environmental contaminants during cleanup, demolition and remediation activities. To support these objectives, an air monitoring program is often required as an integral element of a comprehensive brownfields redevelopment effort. This paper presents a strategic framework for design and execution of an ambient air monitoring program in support of a brownfields remediationmore » effort ongoing in Lawrence, MA. Based on site characterization, the program included sample collection and laboratory analysis of ambient air samples for polychlorinated biphenyls (PCBs), polychlorinated dibenzodioxins and polychlorinated dibenzofurans (PCDDs/PCDFs), total suspended particulate (TSP), inhalable particulate (PM10), and lead. The program included four monitoring phases, identified as background, wintertime, demolition/remediation and post-demolition. Air sampling occurred over a 16 month period during 1996--97, during which time nine sampling locations were utilized to produce approximately 1,500 ambient air samples. Following strict data review and validation procedures, ambient air data interpretation focused on the following: evaluation of upwind/downwind sample pairs, comparison of ambient levels to existing regulatory standards, relation of ambient levels to data reported in the open literature, and, determination of normal seasonal variations in existing background burden, comparison of ambient levels measured during site activity to background levels.« less

Motor performance of tongue with a computer-integrated system under different levels of background physical exertion

PubMed Central

Huo, Xueliang; Johnson-Long, Ashley N.; Ghovanloo, Maysam; Shinohara, Minoru

2015-01-01

The purpose of this study was to compare the motor performance of tongue, using Tongue Drive System, to hand operation for relatively complex tasks under different levels of background physical exertion. Thirteen young able-bodied adults performed tasks that tested the accuracy and variability in tracking a sinusoidal waveform, and the performance in playing two video games that require accurate and rapid movements with cognitive processing using tongue and hand under two levels of background physical exertion. Results show additional background physical activity did not influence rapid and accurate displacement motor performance, but compromised the slow waveform tracking and shooting performances in both hand and tongue. Slow waveform tracking performance by the tongue was compromised with an additional motor or cognitive task, but with an additional motor task only for the hand. Practitioner Summary We investigated the influence of task complexity and background physical exertion on the motor performance of tongue and hand. Results indicate the task performance degrades with an additional concurrent task or physical exertion due to the limited attentional resources available for handling both the motor task and background exertion. PMID:24003900

Factors Affecting Parent’s Perception on Air Quality—From the Individual to the Community Level

PubMed Central

Guo, Yulin; Liu, Fengfeng; Lu, Yuanan; Mao, Zongfu; Lu, Hanson; Wu, Yanyan; Chu, Yuanyuan; Yu, Lichen; Liu, Yisi; Ren, Meng; Li, Na; Chen, Xi; Xiang, Hao

2016-01-01

The perception of air quality significantly affects the acceptance of the public of the government’s environmental policies. The aim of this research is to explore the relationship between the perception of the air quality of parents and scientific monitoring data and to analyze the factors that affect parents’ perceptions. Scientific data of air quality were obtained from Wuhan’s environmental condition reports. One thousand parents were investigated for their knowledge and perception of air quality. Scientific data show that the air quality of Wuhan follows an improving trend in general, while most participants believed that the air quality of Wuhan has deteriorated, which indicates a significant difference between public perception and reality. On the individual level, respondents with an age of 40 or above (40 or above: OR = 3.252; 95% CI: 1.170–9.040), a higher educational level (college and above: OR = 7.598; 95% CI: 2.244–25.732) or children with poor healthy conditions (poor: OR = 6.864; 95% CI: 2.212–21.302) have much more negative perception of air quality. On the community level, industrial facilities, vehicles and city construction have major effects on parents’ perception of air quality. Our investigation provides baseline information for environmental policy researchers and makers regarding the public’s perception and expectation of air quality and the benefits to the environmental policy completing and enforcing. PMID:27187432

Mexico City air quality research initiative. Volume 2, Problem definition, background, and summary of prior research

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

Not Available

1994-06-01

Air pollution in Mexico City has increased along with the growth of the city, the movement of its population, and the growth of employment created by industry. The main cause of pollution in the city is energy consumption. Therefore, it is necessary to take into account the city`s economic development and its prospects when considering the technological relationships between well-being and energy consumption. Air pollution in the city from dust and other particles suspended in the air is an old problem. However, pollution as we know it today began about 50 years ago with the growth of industry, transportation, andmore » population. The level of well-being attained in Mexico City implies a high energy use that necessarily affects the valley`s natural air quality. However, the pollution has grown so fast that the City must act urgently on three fronts: first, following a comprehensive strategy, transform the economic foundation of the city with nonpolluting activities to replace the old industries, second, halt pollution growth through the development of better technologies; and third, use better fuels, emission controls, and protection of wooded areas.« less

Techno-Economic Analysis of Indian Draft Standard Levels for RoomAir Conditioners

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

McNeil, Michael A.; Iyer, Maithili

The Indian Bureau of Energy Efficiency (BEE) finalized its first set of efficiency standards and labels for room air conditioners in July of 2006. These regulations followed soon after the publication of levels for frost-free refrigerators in the same year. As in the case of refrigerators, the air conditioner program introduces Minimum Efficiency Performance Standards (MEPS) and comparative labels simultaneously, with levels for one to five stars. Also like the refrigerator program, BEE defined several successive program phases of increasing stringency. In support of BEE's refrigerator program, Lawrence Berkeley National Laboratory (LBNL) produced an analysis of national impacts of standardsmore » in collaboration with the Collaborative Labeling and Standards Program (CLASP). That analysis drew on LBNL's experience with standards programs in the United States, as well as many other countries. Subsequently, as part of the process for setting optimal levels for air conditioner regulations, CLASP commissioned LBNL to provide support to BEE in the form of a techno-economic evaluation of air conditioner efficiency technologies. This report describes the methodology and results of this techno-economic evaluation. The analysis consists of three components: (1) Cost effectiveness to consumers of efficiency technologies relative to current baseline. (2) Impacts on the current market from efficiency regulations. (3) National energy and financial impacts. The analysis relied on detailed and up-to-date technical data made available by BEE and industry representatives. Technical parameters were used in conjunction with knowledge about air conditioner use patterns in the residential and commercial sectors, and prevailing marginal electricity prices, in order to give an estimate of per-unit financial impacts. In addition, the overall impact of the program was evaluated by combining unit savings with market forecasts in order to yield national impacts. LBNL presented preliminary

A radon daughter deposition model for low background experiments

NASA Astrophysics Data System (ADS)

Rielage, K.; Guiseppe, V. E.; Mastbaum, A.; Elliott, S. R.; Hime, A.

2009-05-01

The next generation low-background detectors operating underground, such as dark matter searches and neutrinoless double-beta decay, aim for unprecedented low levels of radioactive backgrounds. Although the radioactive decays of airborne radon (particularly ^222Rn) and its subsequent daughters present in an experiment are potential backgrounds, more troublesome is the deposition of radon daughters on detector materials. Exposure to radon at any stage of assembly of an experiment can result in surface contamination by daughters supported by the long half life (22 y) of ^210Pb on sensitive locations of a detector. An understanding of the potential surface contamination will enable requirements of radon-reduced air and clean room environments for the assembly of low background experiments. It is known that there are a number of environmental factors that govern the deposition of daughters onto surfaces. However, existing models have not explored the impact of some environmental factors important for low background experiments. A test stand has been constructed to deposit radon daughters on various surfaces under a controlled environment in order to develop a deposition model. Results from this test stand and the resulting deposition model will be presented.

Bi-level Optimization Method of Air-conditioning System Based on Office Building Energy Storage Characteristics

NASA Astrophysics Data System (ADS)

Wang, Qingze; Chen, Xingying; Ji, Li; Liao, Yingchen; Yu, Kun

2017-05-01

The air-conditioning system of office building is a large power consumption terminal equipment, whose unreasonable operation mode leads to low energy efficiency. Realizing the optimization of the air-conditioning system has become one of the important research contents of the electric power demand response. In this paper, in order to save electricity cost and improve energy efficiency, bi-level optimization method of air-conditioning system based on TOU price is put forward by using the energy storage characteristics of the office building itself. In the upper level, the operation mode of the air-conditioning system is optimized in order to minimize the uses’ electricity cost in the premise of ensuring user’ comfort according to the information of outdoor temperature and TOU price, and the cooling load of the air-conditioning is output to the lower level; In the lower level, the distribution mode of cooling load among the multi chillers is optimized in order to maximize the energy efficiency according to the characteristics of each chiller. Finally, the experimental results under different modes demonstrate that the strategy can improve the energy efficiency of chillers and save the electricity cost for users.

Grass pollen counts, air pollution levels and allergic rhinitis severity.

PubMed

Annesi-Maesano, Isabella; Rouve, Sarah; Desqueyroux, Hélène; Jankovski, Roger; Klossek, Jean-Michel; Thibaudon, Michel; Demoly, Pascal; Didier, Alain

2012-01-01

Little is known about the relation between allergic rhinitis severity and airborne pollen in combination with air pollutants. To model the risk of suffering from severe seasonal allergic rhinitis (SAR) as a function of both pollen count and air pollution levels in a large nationwide sample of patients whose SAR was diagnosed by a physician and confirmed by skin prick test positivity or specific immunolglobulin E to common aeroallergens. The severity of SAR symptoms was estimated with the Symptomatic Global Score (SGS) among 36,397 patients suffering from an untreated and uncomplicated SAR between May and August 2004 in metropolitan France. Patients who had an SGS in the upper third quartile were classified as suffering from severe SAR. A multilevel model relating SAR severity, pollen and air pollution was used to take into account the hierarchical data structure. 18.9% of the 17,567 urban patients retained for the analysis suffered from severe rhinitis. At the Lag0 (day of the visit), a rise of 60 grass pollen grains/m(3) increased the risk of suffering from a severe SAR form by 8% in the multileveled model after adjusting for potential confounders and air pollution levels. Results were also confirmed in the subsample of individuals with documented sensitization to grass pollen. Grass pollen count aggravated SAR in terms of symptoms in our nationwide sample. These findings confirm the need for proper treatment and preventive measures in SAR patients sensitized to grass pollen. Copyright © 2012 S. Karger AG, Basel.

Development of an Ultra-Low Background Liquid Scintillation Counter for Trace Level Analysis

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

Erchinger, Jennifer L.; Orrell, John L.; Aalseth, Craig E.

2015-09-01

Low-level liquid scintillation counting (LSC) has been established as one of the radiation detection techniques useful in elucidating environmental processes and environmental monitoring around nuclear facilities. The Ultra-Low Background Liquid Scintillation Counter (ULB-LSC) under construction in the Shallow Underground Laboratory at Pacific Northwest National Laboratory aims to further reduce the MDAs and/or required sample processing. Through layers of passive shielding in conjunction with an active veto and 30 meters water equivalent overburden, the background reduction is expected to be 10 to 100 times below typical analytic low-background liquid scintillation systems. Simulations have shown an expected background of around 14 countsmore » per day. A novel approach to the light collection will use a coated hollow light guide cut into the inner copper shielding. Demonstration LSC measurements will show low-energy detection, spectral deconvolution, and alpha/beta discrimination capabilities, from trials with standards of tritium, strontium-90, and actinium-227, respectively. An overview of the system design and expected demonstration measurements will emphasize the potential applications of the ULB-LSC in environmental monitoring for treaty verification, reach-back sample analysis, and facility inspections.« less

42 CFR 84.181 - Non-powered air-purifying particulate filter efficiency level determination.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 42 Public Health 1 2010-10-01 2010-10-01 false Non-powered air-purifying particulate filter...-purifying particulate filter efficiency level determination. (a) Twenty filters of each non-powered air-purifying particulate respirator model shall be tested for filter efficiency against: (1) A solid sodium...

42 CFR 84.181 - Non-powered air-purifying particulate filter efficiency level determination.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 42 Public Health 1 2011-10-01 2011-10-01 false Non-powered air-purifying particulate filter...-purifying particulate filter efficiency level determination. (a) Twenty filters of each non-powered air-purifying particulate respirator model shall be tested for filter efficiency against: (1) A solid sodium...

42 CFR 84.181 - Non-powered air-purifying particulate filter efficiency level determination.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 42 Public Health 1 2012-10-01 2012-10-01 false Non-powered air-purifying particulate filter...-purifying particulate filter efficiency level determination. (a) Twenty filters of each non-powered air-purifying particulate respirator model shall be tested for filter efficiency against: (1) A solid sodium...

42 CFR 84.181 - Non-powered air-purifying particulate filter efficiency level determination.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 42 Public Health 1 2014-10-01 2014-10-01 false Non-powered air-purifying particulate filter...-purifying particulate filter efficiency level determination. (a) Twenty filters of each non-powered air-purifying particulate respirator model shall be tested for filter efficiency against: (1) A solid sodium...

42 CFR 84.181 - Non-powered air-purifying particulate filter efficiency level determination.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 42 Public Health 1 2013-10-01 2013-10-01 false Non-powered air-purifying particulate filter...-purifying particulate filter efficiency level determination. (a) Twenty filters of each non-powered air-purifying particulate respirator model shall be tested for filter efficiency against: (1) A solid sodium...

A hybrid modeling with data assimilation to evaluate human exposure level

NASA Astrophysics Data System (ADS)

Koo, Y. S.; Cheong, H. K.; Choi, D.; Kim, A. L.; Yun, H. Y.

2015-12-01

Exposure models are designed to better represent human contact with PM (Particulate Matter) and other air pollutants such as CO, SO2, O3, and NO2. The exposure concentrations of the air pollutants to human are determined by global and regional long range transport of global and regional scales from Europe and China as well as local emissions from urban and road vehicle sources. To assess the exposure level in detail, the multiple scale influence from background to local sources should be considered. A hybrid air quality modeling methodology combing a grid-based chemical transport model with a local plume dispersion model was used to provide spatially and temporally resolved air quality concentration for human exposure levels in Korea. In the hybrid modeling approach, concentrations from a grid-based chemical transport model and a local plume dispersion model are added to provide contributions from photochemical interactions, long-range (regional) transport and local-scale dispersion. The CAMx (Comprehensive Air quality Model with Extensions was used for the background concentrations from anthropogenic and natural emissions in East Asia including Korea while the road dispersion by vehicle emission was calculated by CALPUFF model. The total exposure level of the pollutants was finally assessed by summing the background and road contributions. In the hybrid modeling, the data assimilation method based on the optimal interpolation was applied to overcome the discrepancies between the model predicted concentrations and observations. The air quality data from the air quality monitoring stations in Korea. The spatial resolution of the hybrid model was 50m for the Seoul Metropolitan Ares. This example clearly demonstrates that the exposure level could be estimated to the fine scale for the exposure assessment by using the hybrid modeling approach with data assimilation.

Influence of the steady background turbulence level on second sound dynamics in He II II

NASA Astrophysics Data System (ADS)

Dalban-Canassy, M.; Hilton, D. K.; Sciver, S. W. Van

2007-01-01

We report complementary results to our previous publication [Dalban-Canassy M, Hilton DK, Van Sciver SW. Influence of the steady background turbulence level on second sound dynamics in He II. Adv Cryo Eng 2006;51:371-8], both of which are aimed at determining the influence of background turbulence on the breakpoint energy of second sound pulses in He II. The apparatus consists of a channel 175 mm long and 242 mm 2 in cross section immersed in a saturated bath of He II at 1.7 K. A heater at the bottom end generates both background turbulence, through a low level steady heat flux (up to qs = 2.6 kW/m 2), and high intensity square second sound pulses ( qp = 100 or 200 kW/m 2) of variable duration Δ t0 (up to 1 ms). Two superconducting filament sensors, located 25.4 mm and 127 mm above the heater, measure the temperature profiles of the traveling pulses. We present here an analysis of the measurements gathered on the top sensor, and compare them to similar results for the bottom sensor [1]. The strong dependence of the breakpoint energy on the background heat flux previously illustrated is also observed on the top sensor. The present work shows that the ratio of energy received at the top sensor to that at the bottom sensor diminishes with increasing background heat flux.

Influence of air pollution on exhaled carbon monoxide levels in smokers and non-smokers. A prospective cross-sectional study.

PubMed

Maga, Mikołaj; Janik, Maciej K; Wachsmann, Agnieszka; Chrząstek-Janik, Olga; Koziej, Mateusz; Bajkowski, Mateusz; Maga, Paweł; Tyrak, Katarzyna; Wójcik, Krzysztof; Gregorczyk-Maga, Iwona; Niżankowski, Rafał

2017-01-01

The poor air quality and cigarette smoking are the most important reasons for increased carbon monoxide (CO) level in exhaled air. However, the influence of high air pollution concentration in big cities on the exhaled CO level has not been well studied yet. To evaluate the impact of smoking habit and air pollution in the place of living on the level of CO in exhaled air. Citizens from two large cities and one small town in Poland were asked to complete a survey disclosing their place of residence, education level, work status and smoking habits. Subsequently, the CO level in their exhaled air was measured. Air quality data, obtained from the Regional Inspectorates of Environmental Protection, revealed the differences in atmospheric CO concentration between locations. 1226 subjects were divided into 4 groups based on their declared smoking status and place of living. The average CO level in exhaled air was significantly higher in smokers than in non-smokers (p<0.0001) as well as in non-smokers from big cities than non-smokers from small ones (p<0.0001). Created model showed that non-smokers from big cities have odds ratio of 125.3 for exceeding CO cutoff level of 4ppm compared to non-smokers from small towns. The average CO level in exhaled air is significantly higher in smokers than non-smokers. Among non-smokers, the average exhaled CO level is significantly higher in big city than small town citizens. These results suggest that permanent exposure to an increased concentration of air pollution and cigarette smoking affect the level of exhaled CO. Copyright © 2016 Elsevier Inc. All rights reserved.

New insight into the distribution pattern, levels, and risk diagnosis of FRs in indoor and outdoor air at low- and high-altitude zones of Pakistan: Implications for sources and exposure.

PubMed

Khan, Muhammad Usman; Besis, Athanasios; Li, Jun; Zhang, Gan; Malik, Riffat Naseem

2017-10-01

Data regarding flame retardants (FRs) in indoor and outdoor air and their exposure to population are scarce and especially unknown in the case of Pakistan. The current study was designed to probe FR concentrations and distribution pattern in indoor and outdoor air at different altitudinal zones (DAZs) of Pakistan with special emphasis on their risk to the exposed population. In this study, passive air samplers for the purpose of FR deposition were deployed in indoor and outdoor air at the industrial, rural, and background/colder zones/sites. All the indoor and outdoor air samples collected from DAZs were analyzed for the target FRs (9.30-472.30 pg/m 3 ), showing a decreasing trend as follows: ∑NBFRs > ∑PBDEs > ∑DP. However, significant correlations among FRs in the indoor and outdoor air at DAZs signified a similar source of FR origin that is used in different consumer goods. Furthermore, air mass trajectories revealed that movement of air over industrial area sources influenced concentrations of FRs at rural sites. The FR concentrations, estimated daily intake (EDI) and the hazard quotient (HQ), were recorded to be higher in toddlers than those in adults. In addition, indoor air samples showed higher FR levels, EDI and HQ, than outdoor air samples. An elevated FR concentrations and their prevalent exposure risks were recorded in the industrial zones followed by rural and background zones. The HQ for BDE-47 and BDE-99 in the indoor and outdoor air samples at different industrial and rural sites were recorded to be >1 in toddlers and adults, this further warrants a health risk in the population. However, FR investigation in indoor and outdoor air samples will provide a baseline data in Pakistan to take further steps by the government and agencies for its implementations. Copyright © 2017 Elsevier Ltd. All rights reserved.

Do US Ambient Air Lead Levels Have a Significant Impact on Childhood Blood Lead Levels: Results of a National Study

PubMed Central

Brink, LuAnn L.; Talbott, Evelyn O.; Sharma, Ravi K.; Marsh, Gary M.; Wu, Wen Chi; Rager, Judith R.; Strosnider, Heather M.

2013-01-01

Introduction. Although lead paint and leaded gasoline have not been used in the US for thirty years, thousands of US children continue to have blood lead levels (BLLs) of concern. Methods. We investigated the potential association of modeled air lead levels and BLLs ≥ 10 μg/dL using a large CDC database with BLLs on children aged 0–3 years. Percent of children with BLLs ≥ 10 μg/dL (2000–2007) by county and proportion of pre-50 housing and SES variables were merged with the US EPA's National Air Toxics Assessment (NATA) modeled air lead data. Results. The proportion with BLL ≥ 10 μg/dL was 1.24% in the highest air lead counties, and the proportion with BLL ≥ 10 μg/dL was 0.36% in the lowest air lead counties, resulting in a crude prevalence ratio of 3.4. Further analysis using multivariate negative binomial regression revealed that NATA lead was a significant predictor of % BLL ≥ 10 μg/dL after controlling for percent pre-l950 housing, percent rural, and percent black. A geospatial regression revealed that air lead, percent older housing, and poverty were all significant predictors of % BLL ≥ 10 μg/dL. Conclusions. More emphasis should be given to potential sources of ambient air lead near residential areas. PMID:23983719

Can air pollution negate the health benefits of cycling and walking?

PubMed

Tainio, Marko; de Nazelle, Audrey J; Götschi, Thomas; Kahlmeier, Sonja; Rojas-Rueda, David; Nieuwenhuijsen, Mark J; de Sá, Thiago Hérick; Kelly, Paul; Woodcock, James

2016-06-01

Active travel (cycling, walking) is beneficial for the health due to increased physical activity (PA). However, active travel may increase the intake of air pollution, leading to negative health consequences. We examined the risk-benefit balance between active travel related PA and exposure to air pollution across a range of air pollution and PA scenarios. The health effects of active travel and air pollution were estimated through changes in all-cause mortality for different levels of active travel and air pollution. Air pollution exposure was estimated through changes in background concentrations of fine particulate matter (PM2.5), ranging from 5 to 200μg/m3. For active travel exposure, we estimated cycling and walking from 0 up to 16h per day, respectively. These refer to long-term average levels of active travel and PM2.5 exposure. For the global average urban background PM2.5 concentration (22μg/m3) benefits of PA by far outweigh risks from air pollution even under the most extreme levels of active travel. In areas with PM2.5 concentrations of 100μg/m3, harms would exceed benefits after 1h 30min of cycling per day or more than 10h of walking per day. If the counterfactual was driving, rather than staying at home, the benefits of PA would exceed harms from air pollution up to 3h 30min of cycling per day. The results were sensitive to dose-response function (DRF) assumptions for PM2.5 and PA. PA benefits of active travel outweighed the harm caused by air pollution in all but the most extreme air pollution concentrations. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

AirMSPI Level 1B2 V003 New and Reprocessed Data

Atmospheric Science Data Center

2013-12-10

AirMSPI Level 1B2 V003 New and Reprocessed Data PODEX Thursday, December 12, ... The V001 & V002 data were reprocessed as V003, as well as new Pacific targets acquired on February 1, 2013. This release also includes both a terrain and an ellipsoid kml file per date/time/target. More details about the PODEX campaign and AirMSPI participation can be ...

Impact of natural gas extraction on PAH levels in ambient air.

PubMed

Paulik, L Blair; Donald, Carey E; Smith, Brian W; Tidwell, Lane G; Hobbie, Kevin A; Kincl, Laurel; Haynes, Erin N; Anderson, Kim A

2015-04-21

Natural gas extraction, often referred to as "fracking," has increased rapidly in the U.S. in recent years. To address potential health impacts, passive air samplers were deployed in a rural community heavily affected by the natural gas boom. Samplers were analyzed for 62 polycyclic aromatic hydrocarbons (PAHs). Results were grouped based on distance from each sampler to the nearest active well. PAH levels were highest when samplers were closest to active wells. Additionally, PAH levels closest to natural gas activity were an order of magnitude higher than levels previously reported in rural areas. Sourcing ratios indicate that PAHs were predominantly petrogenic, suggesting that elevated PAH levels were influenced by direct releases from the earth. Quantitative human health risk assessment estimated the excess lifetime cancer risks associated with exposure to the measured PAHs. Closest to active wells, the risk estimated for maximum residential exposure was 2.9 in 10 000, which is above the U.S. EPA's acceptable risk level. Overall, risk estimates decreased 30% when comparing results from samplers closest to active wells to those farthest. This work suggests that natural gas extraction may be contributing significantly to PAHs in air, at levels that are relevant to human health.

Impact of natural gas extraction on Pah levels in ambient air

PubMed Central

Paulik, L. Blair; Donald, Carey E.; Smith, Brian W.; Tidwell, Lane G.; Hobbie, Kevin A.; Kincl, Laurel; Haynes, Erin N.; Anderson, Kim A.

2015-01-01

Natural gas extraction, often referred to as “fracking,” has increased rapidly in the U.S. in recent years. To address potential health impacts, passive air samplers were deployed in a rural community heavily affected by the natural gas boom. Samplers were analyzed for 62 polycyclic aromatic hydrocarbons (PAHs). Results were grouped based on distance from each sampler to the nearest active well. PAH levels were highest when samplers were closest to active wells. Additionally, PAH levels closest to natural gas activity were an order of magnitude higher than levels previously reported in rural areas. Sourcing ratios indicate that PAHs were predominantly petrogenic, suggesting that elevated PAH levels were influenced by direct releases from the earth. Quantitative human health risk assessment estimated the excess lifetime cancer risks associated with exposure to the measured PAHs. Closest to active wells, the risk estimated for maximum residential exposure was 2.9 in 10,000, which is above the U.S. EPA's acceptable risk level. Overall, risk estimates decreased 30% when comparing results from samplers closest to active wells to those farthest. This work suggests that natural gas extraction may be contributing significantly to PAHs in air, at levels that are relevant to human health. PMID:25810398

Air pollution and urinary n-acetyl-B-glucosaminidase levels in residents living near a cement plant.

PubMed

Jung, Min Soo; Kim, Jae Yoon; Lee, Hyun Seung; Lee, Chul Gab; Song, Han Soo

2016-01-01

To identify adverse renal effects due to air pollution derived from a cement plant in Korea. Urinary n-acetyl-B-glucosaminidase (U-NAG) levels in residents living near a cement plant were compared to those in a group who lived farther away from the plant. From June to August 2013 and from August to November 2014, laboratory tests for U-NAG and heavy metal were conducted on 547 study participants. Based on the level of air pollution exposure, subjects were divided into the "less exposed group," (LEG) which consisted of 66 persons who lived more than 5 km away from the cement plant, the "more exposed group from the rural area" (MEG-R), which consisted of 272 persons, and the "more exposed group from downtown area" (MEG-D), which consisted of 209 persons who lived within a 1 km radius of the cement plant. U-NAG levels >5.67 U/L were defined as "higher U-NAG" levels. We compared the prevalence of higher U-NAG levels and estimated the adjusted odds ratio (OR) by air pollution exposure using a chi-square test and multiple logistic regression analysis. Further, we estimated the interaction between air pollution exposure and heavy metal exposure in renal toxicity. The OR of higher U-NAG levels by MEG-D and MEG-R compared to LEG was 2.13 (95 % CI 0.86-4.96) and 4.79 (95 CI 1.65-10.01), respectively. Urinary cadmium (U-Cd), urinary mercury (U-Hg), age, occupation, hypertension, and diabetes had a significant association with higher U-NAG levels. However, blood lead (B-Pb), sex, and smoking were not associated with higher U-NAG. Especially, concurrent exposure to heavy metals (U-Hg or/and U-Cd) and air pollution had an additive adverse effect. In the group with both 4 th quartile heavy metal exposure (U-Cd or/and U-Hg) and air pollution exposure, the OR in MEG-R and MEG-D was 6.49 (95 % 1.42-29.65) and 8.12 (95 % CI 1.74-37.92), respectively, after adjustment for age, occupation, hypertension, diabetes. U-NAG levels seem to be affected by air pollution exposure as well

Computational fluid dynamics modeling to assess the impact of roadside barriers on near-road air quality

EPA Science Inventory

Near-road air quality is an issue of emerging concern, with field studies consistently showing elevated air pollutant concentrations adjacent to major roads, usually decreasing to background levels within several hundred meters. Roadside barriers, both vegetative and structural, ...

Trends in motor neuron disease: association with latitude and air lead levels in Spain.

PubMed

Santurtún, Ana; Villar, Alejandro; Delgado-Alvarado, Manuel; Riancho, Javier

2016-08-01

Motor neuron diseases (MND) are a group of disorders characterized by motor neuron degeneration. Among them, amyotrophic lateral sclerosis (ALS) is by far the most common in adulthood. This paper assesses the trend and geographical pattern in MND incidence in Spain and the possible air lead levels effect on this pathology. To confirm this concept, we performed a retrospective analysis of the deaths due to MND in Spain during 2000 and 2013, determined the geographical differences, and explored the relationship between MND and the air levels of lead. Overall, between 2000 and 2013, 11,355 people died in Spain because of MND. Disease mortality significantly increased in recent years (2007-2013) when compared with the first time of the period. Spearman's rank correlation coefficient also showed a statistically significant positive trend (CC = 0.824, p = 0.0002). Among people over 65 years, mortality rates were higher in Northern provinces. Moreover, we found a significant association of MND mortality with higher air lead levels (CC = 0.457, p = 0.01). Our study confirms that MND mortality is increasing in Spain, with a significant latitude gradient, which suggests an important role of environmental exposures. This ecological study suggests that air lead levels may be implicated in ALS pathogenesis.

Air-powder polishing on self-ligating brackets after clinical use: effects on debris levels.

PubMed

Aragón, Mônica L S Castro; Lima, Leandro Santiago; Normando, David

2016-01-01

Debris buildup on brackets and arch surfaces is one of the main factors that can influence the intensity of friction between bracket and orthodontic wire. This study sought to evaluate the effect of air-powder polishing cleaning on debris levels of self-ligating ceramic brackets at the end of orthodontic treatment, compared to the behavior of conventional brackets. Debris levels were evaluated in metal conventional orthodontic brackets (n = 42) and ceramic self-ligating brackets (n = 42) on canines and premolars, arranged in pairs. There were brackets with and without air-powder polishing. At the end of orthodontic treatment, a hemiarch served as control and the contralateral hemiarch underwent prophylaxis with air-powder polishing. Debris buildup in bracket slots was assessed through images, and Wilcoxon test was used to analyze the results. The median debris levels were statistically lower in the conventional metal brackets compared to self-ligating ones (p = 0.02), regarding brackets not submitted to air-powder polishing. Polishing significantly reduced debris buildup to zero in both systems, without differences between groups. Ceramic self-ligating brackets have a higher debris buildup in comparison to conventional metal brackets in vivo, but prophylaxis with sodium bicarbonate jet was effective in reducing debris levels in self-ligating and also in conventional brackets.

Anemia Prevalence and Hemoglobin Levels are Associated with Long-Term Exposure to Air Pollution in an Older Population

PubMed Central

Honda, Trenton; Pun, Vivian C.; Manjourides, Justin; Suh, Helen

2017-01-01

BACKGROUND Anemia, a highly prevalent disorder in elderly populations, is associated with numerous adverse health outcomes, including increased mortality, impaired functional status and cognitive disorders. Approximately two-thirds of anemia in American elderly is caused by chronic inflammation or is unexplained. A potential contributing factor may include air pollution exposures, which have been shown to increase systemic inflammation and affect erythropoiesis. Few studies, however, have investigated the associations of air pollution on hemoglobin levels and anemia. METHODS We used linear regression models and modified Poisson regression with robust error variance to examine the associations of particulate matter (PM2.5) and nitrogen dioxide (NO2) on hemoglobin concentrations and prevalence of anemia, respectively, among 4,121 older Americans enrolled in the National Social Life, Health, and Aging Project. We estimated participant-specific exposures to PM2.5 using spatio-temporal models, and to NO2 using nearest measurements from Environmental Protection Agency’s Air Quality System. Hemoglobin levels were measured for participants in each of two data collection waves from dried blood spots. Anemia was defined using World Health Organization hemoglobin-based criteria of <13 and <12 g/dL for men and women, respectively. Models were adjusted for age, sex, smoking status, race, income, education, neighborhood socioeconomic status, region, urbanicity and medication use. Mediation by C-reactive protein (CRP), a marker of systemic inflammation, was also investigated. RESULTS An inter-quartile range (IQR, 3.9 μg/m3) increase in the one-year moving average PM2.5 was positively associated with anemia prevalence (prevalence ratio, or PR 1.33, 95% CI: 1.23, 1.45) and decreases in average hemoglobin of 0.81 g/dL (p<0.001). Similarly, an IQR (9.6 ppb) increase in NO2 was associated with anemia prevalence (PR 1.43, 95% CI: 1.25, 1.63) and a decrease in average hemoglobin of 0

Regional Air Pollutions in Three Different Regions of Asia From a Transcontinental Transport Perspective

NASA Astrophysics Data System (ADS)

Pochanart, P.; Kanaya, Y.; Komazaki, Y.; Liu, Y.; Akimoto, H.

2007-12-01

Asia is known as one of the regions with the fastest rate of growing in industrialization and urbanization. As a result, the rapid increases of large-scale air pollution in Asia emerge as a serious concern at both domestic and international levels. Apart from the problems of air quality degradation, emission control, environmental risk, and health effect in a domestic level, evidences from scientific studies indicate that by the long-range transport, Asian air pollution is becoming a global problem. Observations and model studies confirm that air pollution from Asia could be transported to North America or farther. In this work, we investigate the Asian air pollutions, in particular ozone and some other atmospheric components such as carbon monoxide and black carbon, from the ground- based observations in the three different regions, namely 1) background region of Siberia and central Asia, 2) highly anthropogenic region in eastern China, and 3) the rim region of the Asia-Pacific. In a transcontinental transport perspective, these regions are regarded as the inflow region, source region, and outflow region of Asia, respectively. From the results, it is found that the influences from large-scale emission in East Asia are observed clearly in the source region, and to the significant extent in the outflow region. For the inflow region of Asia, our data in Siberia and Kyrgyzstan indicate that air masses in this region are mostly intact from large-scale anthropogenic emission, and remain much of the global background atmospheric pollution characteristic. When the air masses are transported to source region, the air pollutants level increased sharply and frequent episodes of extremely high pollutions have been observed. Our results show good correlation between the residence time of air masses over the source region in eastern China and the observed levels of air pollutants verifying the strong enhancements by anthropogenic emissions from industrialization and

Population-Level Exposure to Particulate Air Pollution during Active Travel: Planning for Low-Exposure, Health-Promoting Cities

PubMed Central

Hankey, Steve; Lindsey, Greg; Marshall, Julian D.

2016-01-01

Background: Providing infrastructure and land uses to encourage active travel (i.e., bicycling and walking) are promising strategies for designing health-promoting cities. Population-level exposure to air pollution during active travel is understudied. Objectives: Our goals were a) to investigate population-level patterns in exposure during active travel, based on spatial estimates of bicycle traffic, pedestrian traffic, and particulate concentrations; and b) to assess how those exposure patterns are associated with the built environment. Methods: We employed facility–demand models (active travel) and land use regression models (particulate concentrations) to estimate block-level (n = 13,604) exposure during rush-hour (1600–1800 hours) in Minneapolis, Minnesota. We used the model-derived estimates to identify land use patterns and characteristics of the street network that are health promoting. We also assessed how exposure is correlated with indicators of health disparities (e.g., household income, proportion of nonwhite residents). Our work uses population-level rates of active travel (i.e., traffic flows) rather than the probability of walking or biking (i.e., “walkability” or “bikeability”) to assess exposure. Results: Active travel often occurs on high-traffic streets or near activity centers where particulate concentrations are highest (i.e., 20–42% of active travel occurs on blocks with high population-level exposure). Only 2–3% of blocks (3–8% of total active travel) are “sweet spots” (i.e., high active travel, low particulate concentrations); sweet spots are located a) near but slightly removed from the city-center or b) on off-street trails. We identified 1,721 blocks (~ 20% of local roads) where shifting active travel from high-traffic roads to adjacent low-traffic roads would reduce exposure by ~ 15%. Active travel is correlated with population density, land use mix, open space, and retail area; particulate concentrations were

33. View from roof of Hwing, with Gwing in background, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

33. View from roof of H-wing, with G-wing in background, looking southwest - Offutt Air Force Base, Strategic Air Command Headquarters & Command Center, Headquarters Building, 901 SAC Boulevard, Bellevue, Sarpy County, NE

Rural southeast Texas air quality measurements during the 2006 Texas Air Quality Study.

PubMed

Schade, Gunnar W; Khan, Siraj; Park, Changhyoun; Boedeker, Ian

2011-10-01

The authors conducted air quality measurements of the criteria pollutants carbon monoxide, nitrogen oxides, and ozone together with meteorological measurements at a park site southeast of College Station, TX, during the 2006 Texas Air Quality Study II (TexAQS). Ozone, a primary focus of the measurements, was above 80 ppb during 3 days and above 75 ppb during additional 8 days in summer 2006, suggestive of possible violations of the ozone National Ambient Air Quality Standard (NAAQS) in this area. In concordance with other air quality measurements during the TexAQS II, elevated ozone mixing ratios coincided with northerly flows during days after cold front passages. Ozone background during these days was as high as 80 ppb, whereas southerly air flows generally provided for an ozone background lower than 40 ppb. Back trajectory analysis shows that local ozone mixing ratios can also be strongly affected by the Houston urban pollution plume, leading to late afternoon ozone increases of as high as 50 ppb above background under favorable transport conditions. The trajectory analysis also shows that ozone background increases steadily the longer a southern air mass resides over Texas after entering from the Gulf of Mexico. In light of these and other TexAQS findings, it appears that ozone air quality is affected throughout east Texas by both long-range and regional ozone transport, and that improvements therefore will require at least a regionally oriented instead of the current locally oriented ozone precursor reduction policies.

Sources and levels of background noise in the NASA Ames 40- by 80-foot wind tunnel

NASA Technical Reports Server (NTRS)

Soderman, Paul T.

1988-01-01

Background noise levels are measured in the NASA Ames Research Center 40- by 80-Foot Wind Tunnel following installation of a sound-absorbent lining on the test-section walls. Results show that the fan-drive noise dominated the empty test-section background noise at airspeeds below 120 knots. Above 120 knots, the test-section broadband background noise was dominated by wind-induced dipole noise (except at lower harmonics of fan blade-passage tones) most likely generated at the microphone or microphone support strut. Third-octave band and narrow-band spectra are presented for several fan operating conditions and test-section airspeeds. The background noise levels can be reduced by making improvements to the microphone wind screen or support strut. Empirical equations are presented relating variations of fan noise with fan speed or blade-pitch angle. An empirical expression for typical fan noise spectra is also presented. Fan motor electric power consumption is related to the noise generation. Preliminary measurements of sound absorption by the test-section lining indicate that the 152 mm thick lining will adequately absorb test-section model noise at frequencies above 300 Hz.

Exposure to ambient air pollution--does it affect semen quality and the level of reproductive hormones?

PubMed

Radwan, Michał; Jurewicz, Joanna; Polańska, Kinga; Sobala, Wojciech; Radwan, Paweł; Bochenek, Michał; Hanke, Wojciech

2016-01-01

Ambient air pollution has been associated with a variety of reproductive disorders. However, a limited amount of research has been conducted to examine the association between air pollution and male reproductive outcomes, specifically semen quality. The present study was designed to address the hypothesis that exposure to fluctuating levels of specific air pollutants adversely affects sperm parameters and the level of reproductive hormones. The study population consisted of 327 men who were attending an infertility clinic in Łodź, Poland for diagnostic purposes and who had normal semen concentration of 15-300 mln/ml. All participants were interviewed and provided a semen sample. Air quality data were obtained from AirBase database. The statistically significant association was observed between abnormalities in sperm morphology and exposure to all examined air pollutants (PM10, PM2.5, SO2, NOX, CO). Exposure to air pollutants (PM10, PM2.5, CO, NOx) was also negatively associated with the level of testosterone. Additional exposure to PM2.5, PM10 increase the percentage of cells with immature chromatin (HDS). The present study provides suggestive evidence of an association between ambient air pollution and sperm quality. Further research is needed to explore this association in more detail. Individual precise exposure assessment would be needed for more detailed risk characterization.

Influence of background particulate matter (PM) on urban air quality in the Pacific Northwest.

PubMed

Timonen, H; Wigder, N; Jaffe, D

2013-11-15

Elevated particulate matter concentrations due to Asian long-range transport (LRT) are frequently observed in the free troposphere (FT) above the Pacific Northwest, U.S. Transport of this aerosol from the FT to the boundary layer (BL) and its effect to local air quality remain poorly constrained. We used data collected at the Mount Bachelor observatory (MBO, 2.8 km a.s.l) and from ground stations in the Pacific Northwest to study transport of fine particulate matter (PM) from the FT to the BL. During Asian LRT episodes PM concentrations were clearly elevated above the corresponding monthly averages at MBO as well as at low elevation sites across Washington and Oregon. Also, a clear correlation between MBO and low elevation sites was observed, indicating that LRT episodes are seen in both the FT and BL. In addition, drum impactor measurements show that the chemical composition of PM at MBO was similar to that measured at the BL sites. Using a simple regression model, we estimate that during springtime, when the transport from Asia is most effective, the contribution of Asian sources to PM2.5 in clean background areas of the Pacific Northwest was on average 1.7 μg m(-3) (representing approximately 50-80% of PM). The influence of LRT PM was also seen in measurement stations situated in the urban and urban background areas. However, the fraction of LRT PM was less pronounced (36-50% of PM) due to larger local emissions in the urban areas. Copyright © 2013 Elsevier Ltd. All rights reserved.

Air quality in Moscow megacity: basic level and extreme cases

NASA Astrophysics Data System (ADS)

Pankratova, N.; Skorokhod, A.; Moiseenko, K.

2012-04-01

Moscow is one of the largest megacities in the world. Total annual emissions of polluting substances into the atmosphere in Moscow is likely to be about 2,0 mln. t. More than 90% of pollutants are emitted by traffic. Problem of air quality assessment is very urgent for Moscow both to alarm population and to compare with other world megacities. To study contemporary structure of atmospheric pollution over Moscow megacity data on air composition (including CO, NO, NO2, O3, CH4, CO2, SO2, NMHC, aerosol) obtained since 2002 has been analyzed. The monitoring site is located at Moscow State University meteorological observatory on South-West of Moscow. All observations are provided by A.M. Obukhov Institute of Atmospheric Physics RAS. Due to these continuous measurements typical (basic) level of pollution as well as extreme cases have been studied. The relationship between O3, NOx and VOCs were analyzed as well. Due to weather conditions (cyclonic regime is dominated) concentrations of pollutants usually do not reach dangerous levels but sometimes they are high. The case of abnormal hot and dry weather in the summer of 2010 was investigated. Many Russians were suffering from the record-breaking heat and the worst drought in 40 years. The heat was caused by very intensive and stable blocking anticyclone that established in Moscow since June, 18 till August, 18. Anticyclone of such strength has been never observed before. During 33 days in succession surface air temperature exceeded 30°C. During these 2 months troposphere over ETR was almost closed for western winds. Hot weather led to numerous forest and peat fires (about 29,000 cases) with total covered area about 12,000 km2. One of aftermaths was significant change of atmospheric composition. Many cities and settlements were covered by dense haze from fires. Evident presence of high amount of aerosol in the ambient air caused anxiety and application of safeguards. Meanwhile, less obvious increase of concentrations of

Risk management in air protection in the Republic of Croatia.

PubMed

Peternel, Renata; Toth, Ivan; Hercog, Predrag

2014-03-01

In the Republic of Croatia, according to the Air Protection Act, air pollution assessment is obligatory on the whole State territory. For individual regions and populated areas in the State a network has been established for permanent air quality monitoring. The State network consists of stations for measuring background pollution, regional and cross-border remote transfer and measurements as part of international government liabilities, then stations for measuring air quality in areas of cultural and natural heritage, and stations for measuring air pollution in towns and industrial zones. The exceeding of alert and information threshold levels of air pollutants are related to emissions from industrial plants, and accidents. Each excess represents a threat to human health in case of short-time exposure. Monitoring of alert and information threshold levels is carried out at stations from the state and local networks for permanent air quality monitoring according to the Air Quality Measurement Program in the State network for permanent monitoring of air quality and air quality measurement programs in local networks for permanent air quality monitoring. The State network for permanent air quality monitoring has a developed automatic system for reporting on alert and information threshold levels, whereas many local networks under the competence of regional and local self-governments still lack any fully installed systems of this type. In case of accidents, prompt action at all responsibility levels is necessary in order to prevent crisis and this requires developed and coordinated competent units of State Administration as well as self-government units. It is also necessary to be continuously active in improving the implementation of legislative regulations in the field of crises related to critical and alert levels of air pollutants, especially at local levels.

Determination of radionuclide concentrations in ground level air using the ASS-500 high volume sampler

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

Frenzel, E.; Arnold, D.; Wershofen, H.

1996-06-01

A method for determination of radionuclide concentrations in air aerosol samples collected by the high volume aerosol sampler ASS-500 was elaborated. The aerosol sampling station ASS-500 is a Stand alone, all-weather proofed instrument. It is designed for representative sampling of airborne radionuclides from ground level air at a height of about 1.5 m above ground level. The ASS-500 station enables continuous air monitoring both normal and emergency Situations. The collection of aerosols on the Petrianov FPP-15-1.5 type filter out of an air volume of about 100,000 m{sup 3} (sampling period 1 wk) or of about 250,000 m{sup 3} (sampling periodmore » 3 wk) admits accurate spectrometric low level measurements of natural and artificial radionuclides. The achieved detection limit is 0.5 {mu}Bq m{sup -3} and 0.2 {mu}Bq m{sup -3} for {sup 137}Cs, respectively. A new developed air flow Meter system allows to enhance the collected air volume to about 150,000 m{sup 3} per week and lowers the detection limit to <0.4 {mu}Bq m{sup -3} for {sup 137}Cs for weekly collected aerosol samples. In Poland the CLOR uses 9 Stations ASS-500 at different sites as atmospheric radioactivity control system. On the basis of spectrometric measurements of natural and artificial radionuclides in the collected aerosol samples at the different sites, CLOR establishes a weekly report about the radiological situation at Poland for responsible authorities. The very low achievable detection limit of the Station ASS-500 due 10 the high air flow fate and the long possible sampling period were the key argument for other government radiation protection authorities in Europe to introduce the Station ASS-500 into their low level radionuclide atmospheric monitoring programs (Austria, Belarus, France, Germany, Iceland, Spain, Switzerland, Ukraine).« less

Indoor air quality levels in a University Hospital in the Eastern Province of Saudi Arabia

PubMed Central

El-Sharkawy, Mahmoud F.; Noweir, Mohamed E. H.

2014-01-01

Aim of the Study: The complex hospital environment requires special attention to ensure a healthy indoor air quality (IAQ) to protect patients and healthcare workers against hospital-acquired infections and occupational diseases. Poor hospital IAQ may cause outbreaks of building-related illness such as headaches, fatigue, eye, and skin irritations, and other symptoms. The general objective for this study was to assess IAQ inside a large University hospital at Al-Khobar City in the Eastern Province of Saudi Arabia. Materials and Methods: Different locations representing areas where most activities and tasks are performed were selected as sampling points for air pollutants in the selected hospital. In addition, several factors were studied to determine those that were most likely to affect the IAQ levels. The temperature and relative percent humidity of different air pollutants were measured simultaneously at each location. Results: The outdoor levels of all air pollutant levels, except volatile organic compounds (VOCs), were higher than the indoor levels which meant that the IAQ inside healthcare facilities (HCFs) were greatly affected by outdoor sources, particularly traffic. The highest levels of total suspended particulates (TSPs) and those less than 10 microns (PM10) inside the selected hospital were found at locations that are characterized with m4ore human activity. Conclusions: Levels of particulate matter (both PM10 and TSP) were higher than the Air Quality Guidelines (AQGs). The highest concentrations of the fungal species recorded were Cladosporium and Penicillium. Education of occupants of HCF on IAQ is critical. They must be informed about the sources and effects of contaminants and the proper operation of the ventilation system. PMID:24696632

Two Disciplines of Examiners? The Effect of Professional Background and Level of Experience in Grade-Setting.

ERIC Educational Resources Information Center

Havik, Odd Erik

1980-01-01

Focuses on the influence of examiners' level of experience and professional background on grades given in oral and written undergraduate examinations in psychology. Level of experience was found to have no significant effect. Clinical psychologists gave more laudabilis grades on oral exams and academic psychologists on essay exams. (JD)

Characterizing the spatial variability of local and background concentration signals for air pollution at the neighbourhood scale

NASA Astrophysics Data System (ADS)

Shairsingh, Kerolyn K.; Jeong, Cheol-Heon; Wang, Jonathan M.; Evans, Greg J.

2018-06-01

Vehicle emissions represent a major source of air pollution in urban districts, producing highly variable concentrations of some pollutants within cities. The main goal of this study was to identify a deconvolving method so as to characterize variability in local, neighbourhood and regional background concentration signals. This method was validated by examining how traffic-related and non-traffic-related sources influenced the different signals. Sampling with a mobile monitoring platform was conducted across the Greater Toronto Area over a seven-day period during summer 2015. This mobile monitoring platform was equipped with instruments for measuring a wide range of pollutants at time resolutions of 1 s (ultrafine particles, black carbon) to 20 s (nitric oxide, nitrogen oxides). The monitored neighbourhoods were selected based on their land use categories (e.g. industrial, commercial, parks and residential areas). The high time-resolution data allowed pollutant concentrations to be separated into signals representing background and local concentrations. The background signals were determined using a spline of minimums; local signals were derived by subtracting the background concentration from the total concentration. Our study showed that temporal scales of 500 s and 2400 s were associated with the neighbourhood and regional background signals respectively. The percent contribution of the pollutant concentration that was attributed to local signals was highest for nitric oxide (NO) (37-95%) and lowest for ultrafine particles (9-58%); the ultrafine particles were predominantly regional (32-87%) in origin on these days. Local concentrations showed stronger associations than total concentrations with traffic intensity in a 100 m buffer (ρ:0.21-0.44). The neighbourhood scale signal also showed stronger associations with industrial facilities than the total concentrations. Given that the signals show stronger associations with different land use suggests that

Time course of EEG background activity level before spontaneous awakening in infants.

PubMed

Zampi, Chiara; Fagioli, Igino; Salzarulo, Piero

2002-12-01

This research aimed to investigate the time course of the cortical activity level preceding spontaneous awakening as a function of age and state. Two groups of infants (1-4 and 9-14 weeks of age) were continuously monitored by polygraphic recording and behavioural observation during the night. The electroencephalographic (EEG) activity recorded by the C3-O1 lead was analysed through an automatic analysis method which provides, for each 30-s epoch, a single measure, time domain based, of the EEG synchronization. The EEG parameter values were computed in the 6 min preceding each awakening out of non-rapid eye movement (NREM) sleep and out of rapid eye movement (REM) sleep. The EEG background activity level did not change in the minutes preceding awakening out of REM sleep. Awakening out of NREM sleep was preceded by a change of EEG activity level in the direction of higher activation with different time course according to the age. Both REM and NREM sleep results suggest that a high level of EEG activity is a prerequisite for the occurrence of a spontaneous awakening.

Air transparent soundproof window

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

Kim, Sang-Hoon, E-mail: shkim@mmu.ac.kr; Lee, Seong-Hyun

2014-11-15

A soundproof window or wall which is transparent to airflow is presented. The design is based on two wave theories: the theory of diffraction and the theory of acoustic metamaterials. It consists of a three-dimensional array of strong diffraction-type resonators with many holes centered on each individual resonator. The negative effective bulk modulus of the resonators produces evanescent wave, and at the same time the air holes with subwavelength diameter existed on the surfaces of the window for macroscopic air ventilation. The acoustic performance levels of two soundproof windows with air holes of 20mm and 50mm diameters were measured. Themore » sound level was reduced by about 30 - 35dB in the frequency range of 400 - 5,000Hz with the 20mm window, and by about 20 - 35dB in the frequency range of 700 - 2,200Hz with the 50mm window. Multi stop-band was created by the multi-layers of the window. The attenuation length or the thickness of the window was limited by background noise. The effectiveness of the soundproof window with airflow was demonstrated by a real installation.« less

Background noise analysis in urban airport surroundings of Brazilian cities, Congonhas Airport, São Paulo

PubMed Central

Scatolini, Fabio; Alves, Cláudio Jorge Pinto

2016-01-01

ABSTRACT OBJECTIVE To perform a quantitative analysis of the background noise at Congonhas Airport surroundings based on large sampling and measurements with no interruption. METHODS Measuring sites were chosen from 62 and 72 DNL (day-night-level) noise contours, in urban sites compatible with residential use. Fifteen sites were monitored for at least 168 hours without interruption or seven consecutive days. Data compilation was based on cross-reference between noise measurements and air traffic control records, and results were validated by airport meteorological reports. Preliminary diagnoses were established using the standard NBR-13368. Background noise values were calculated based on the Sound Exposure Level (SEL). Statistic parameters were calculated in one-hour intervals. RESULTS Only four of the fifteen sites assessed presented aircraft operations as a clear cause for the noise annoyance. Even so, it is possible to detect background noise levels above regulation limits during periods of low airport activity or when it closes at night. CONCLUSIONS All the sites monitored showed background noise levels above regulation limits between 7:00 and 21:00. In the intervals between 6:00-6:59 and 21:00-22:59 the noise data, when analyzed with the current airport operational characteristics, still allow the development of additional mitigating measures. PMID:28099658

The effect of long-range air mass transport pathways on PM10 and NO2 concentrations at urban and rural background sites in Ireland: Quantification using clustering techniques.

PubMed

Donnelly, Aoife A; Broderick, Brian M; Misstear, Bruce D

2015-01-01

The specific aims of this paper are to: (i) quantify the effects of various long range transport pathways nitrogen dioxide (NO2) and particulate matter with diameter less than 10μm (PM10) concentrations in Ireland and identify air mass movement corridors which may lead to incidences poor air quality for application in forecasting; (ii) compare the effects of such pathways at various sites; (iii) assess pathways associated with a period of decreased air quality in Ireland. The origin of and the regions traversed by an air mass 96h prior to reaching a receptor is modelled and k-means clustering is applied to create air-mass groups. Significant differences in air pollution levels were found between air mass cluster types at urban and rural sites. It was found that easterly or recirculated air masses lead to higher NO2 and PM10 levels with average NO2 levels varying between 124% and 239% of the seasonal mean and average PM10 levels varying between 103% and 199% of the seasonal mean at urban and rural sites. Easterly air masses are more frequent during winter months leading to higher overall concentrations. The span in relative concentrations between air mass clusters is highest at the rural site indicating that regional factors are controlling concentration levels. The methods used in this paper could be applied to assist in modelling and forecasting air quality based on long range transport pathways and forecast meteorology without the requirement for detailed emissions data over a large regional domain or the use of computationally demanding modelling techniques.

Carbon-13 Isotopic Abundance and Concentration of Atmospheric Methane for Background Air in the Southern and Northern Hemispheres from 1978 to 1989 (NDP-049)

DOE Data Explorer

Stevens, C. M. [Chemical Technology Division, Argonne National Laboratory, Argonne, Illinois (USA)

2012-01-01

This data package presents atmospheric CH4 concentration and 13C isotopic abundance data derived from air samples collected over the period 1978-1989 at globally distributed clean-air sites. The data set comprises 201 records, 166 from the Northern Hemisphere and 35 from the Southern Hemisphere. The air samples were collected mostly in rural or marine locations remote from large sources of CH4 and are considered representative of tropospheric background conditions. The air samples were processed by isolation of CH4 from air and conversion to CO2 for isotopic analysis by isotope ratio mass spectrometry. These data represent one of the earliest records of 13C isotopic yy!measurements for atmospheric methane and have been used to refine estimates of CH4 emissions, calculate annual growth rates of emissions from changing sources, and provide evidence for changes in the rate of atmospheric removal of CH4. The data records consist of sample collection date; number of samples combined for analysis; sampling location; analysis date; CH4 concentration; 13C isotopic abundance; and flag codes to indicate outliers, repeated analyses, and other information.

Effect of Background Luminance Level on the Assessment of Color Visual Acuity Using Colored Landolt Rings in Young Healthy Subjects.

PubMed

Tanaka, Yoshiki; Yokoyama, Sho; Horai, Rie; Kojima, Takashi; Hiroyuki, Sato; Kato, Yukihito; Takagi, Mari; Nakamura, Hideki; Tanaka, Kiyoshi; Ichikawa, Kazuo; Tanabe, Shoko

2018-03-01

To evaluate the color visual acuity (CVA) of young healthy subjects using colored Landolt rings and the effect of background luminance level on the CVA. We measured the CVA of 20 young healthy subjects (age: 23.8 ± 3.8 years) with different colors using a computer and a liquid crystal display, with 15 Landolt ring colors (30 cd/m 2 ) with a background luminance of 30 cd/m 2 , and then 100 cd/m 2 . We then used different background luminance levels (15-50 cd/m 2 ) using four Landolt ring colors (red, green-yellow, green, and blue-green) to evaluate the effect of the background luminance level on CVA. The CVA significantly differed among the colors with a background luminance of 30 cd/m 2 (p < 0.0001). Green-yellow and blue-purple had poor CVA (high LogMAR value; 0.808 ± 0.107 and 0.633 ± 0.150, respectively) with a background luminance of 30 cd/m 2 (same luminance as the Landolt rings). There were no significant differences in the CVAs among the colors with a background luminance of 100 cd/m 2 (p = 0.5999). There were no significant difference in the CVA between background luminance 30 cd/m 2 and other luminance level ranging from 28 to 32 cd/m 2 for colors of red, green-yellow, green, and blue-green. The results reveal that the background luminance of Landolt rings affects the CVA. Distinctive CVAs for each color are measured by equalizing the luminance between the Landolt ring and the background. We consider that the poor CVAs of these colors reflect the visual function of S-cone, because GY and BP are included in the confusion locus of tritan axis on the chromaticity diagram. We believe that CVA assessment may be useful for individuals who have known or suspected ocular dysfunction or color vision deficiencies.

Effect Measure Modification of Blood Lead-Air Lead Slope Factors

EPA Science Inventory

Background: There is abundant literature finding that blood lead (PbB) levels are directly influenced by susceptibility factors including race and ethnicity, age, and housing. However, no study has explored how susceptibility factors influence the PbB-air lead (PbA) relationship...

Final Environmental Assessment for Low-Level Flight Testing, Evaluation, and Training, Edwards Air Force Base

DTIC Science & Technology

2005-05-01

4. TITLE AND SUBTITLE Final Environmental Assessment for Low-Level Flight Testing, Evaluation, and Training, Edwards Air Force Base 5a. CONTRACT...NAME(S) AND ADDRESS(ES) Air Force Flight Test Center,Environmental Management Directorate,Edwards AFB,CA,93524 8. PERFORMING ORGANIZATION REPORT...DISTRIBUTION/AVAILABILITY STATEMENT Approved for public release; distribution unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT The U.S. Air Force Flight Test

A Well-Mixed Computational Model for Estimating Room Air Levels of Selected Constituents from E-Vapor Product Use.

PubMed

Rostami, Ali A; Pithawalla, Yezdi B; Liu, Jianmin; Oldham, Michael J; Wagner, Karl A; Frost-Pineda, Kimberly; Sarkar, Mohamadi A

2016-08-16

Concerns have been raised in the literature for the potential of secondhand exposure from e-vapor product (EVP) use. It would be difficult to experimentally determine the impact of various factors on secondhand exposure including, but not limited to, room characteristics (indoor space size, ventilation rate), device specifications (aerosol mass delivery, e-liquid composition), and use behavior (number of users and usage frequency). Therefore, a well-mixed computational model was developed to estimate the indoor levels of constituents from EVPs under a variety of conditions. The model is based on physical and thermodynamic interactions between aerosol, vapor, and air, similar to indoor air models referred to by the Environmental Protection Agency. The model results agree well with measured indoor air levels of nicotine from two sources: smoking machine-generated aerosol and aerosol exhaled from EVP use. Sensitivity analysis indicated that increasing air exchange rate reduces room air level of constituents, as more material is carried away. The effect of the amount of aerosol released into the space due to variability in exhalation was also evaluated. The model can estimate the room air level of constituents as a function of time, which may be used to assess the level of non-user exposure over time.

Exploring the background features of acidic and basic air pollutants around an industrial complex using data mining approach.

PubMed

Chen, Ho-Wen; Tsai, Ching-Tsan; She, Chin-Wen; Lin, Yo-Chen; Chiang, Chow-Feng

2010-11-01

Air pollution data around a monitored site are normally difficult to analyze due to highly inter-related meteorological and topographical factors on top of many complicated atmospheric chemical interactions occurred in local and regional wind fields. The challenge prompts this study to develop a comprehensive data-mining algorithm of cluster analysis followed by meteorological and interspecies correlations to mitigate the inherent data complexity and dissimilarity. This study investigated the background features of acidic and basic air pollutants around a high-tech industrial park in Taiwan. Monthly samplings were taken at 10 sites around the park in a year. The temporal distribution plots show a baseline with two characteristic groups of high and low peaks. Hierarchical cluster analysis confirms that high peaks were primarily associated with low speed south wind in summer for all the chemical species, except for F(-), Cl(-), NH(3) and HF. Crosschecking with the topographical map identifies several major external sources in south and southwest. Further meteorological correlation suggests that HCl is highly positively associated with humidity, while Cl(-) is highly negatively associated with temperature, both for most stations. Interestingly, HNO(3) is highly negatively associated with wind speed for most stations and the hotspot was found in summer and around the foothill of Da-Tu Mountain in the northwest, a stagnant pocket on the study site. However, F(-) is highly positively associated with wind speed at downwind stations to the prevailing north wind in winter, indicating an internal source from the north. The presence of NH(4)(+) stimulates the formation of NO(3)(-), SO(4)(-2) (R=0.7), and HNO(3), H(2)SO(4), NH(3) (R=0.3-0.4). As H(2)SO(4) could be elevated to a level as high as 40% of the regulated standard, species interactions may be a dominate mechanism responsible for the substantial increase in summer from external sources. Copyright © 2010 Elsevier Ltd

Air-soil exchange of PCBs: levels and temporal variations at two sites in Turkey.

PubMed

Yolsal, Didem; Salihoglu, Güray; Tasdemir, Yücel

2014-03-01

Seasonal distribution of polychlorinated biphenyls (PCBs) at the air-soil intersection was determined for two regions: one with urban characteristics where traffic is dense (BUTAL) and the other representing the coastal zone (Mudanya). Fifty-one air and soil samples were simultaneously collected. Total PCB (Σ82 PCB) levels in the soil samples collected during a 1-year period ranged between 105 and 7,060 pg/g dry matter (dm) (BUTAL) and 110 and 2,320 pg/g dm (Mudanya). Total PCB levels in the gaseous phase were measured to be between 100 and 910 pg/m(3) (BUTAL) and 75 and 1,025 pg/m(3) (Mudanya). Variations in the concentrations were observed depending on the season. Though the PCB concentrations measured in the atmospheres of both regions in the summer months were high, they were found to be lower in winter. However, while soil PCB levels were measured to be high at BUTAL during summer months, they were found to be high during winter months in Mudanya. The direction and amount of the PCB movement were determined by calculating the gaseous phase change fluxes at air-soil intersection. While a general PCB movement from soil to air was found for BUTAL, the PCB movement from air to soil was calculated for the Mudanya region in most of the sampling events. During the warmer seasons PCB movement towards the atmosphere was observed due to evaporation from the soil. With decreases in the temperature, both decreases in the number of PCB congeners occurring in the air and a change in the direction of some congeners were observed, possibly caused by deposition from the atmosphere to the soil. 3-CB and 4-CB congeners were found to be dominant in the atmosphere, and 4-, 5-, and 6-CBs were found to dominate in the surface soils.

Traffic-related Air Pollution and Attention in Primary School Children

PubMed Central

Suades-González, Elisabet; García-Esteban, Raquel; Rivas, Ioar; Pujol, Jesús; Alvarez-Pedrerol, Mar; Forns, Joan; Querol, Xavier; Basagaña, Xavier

2017-01-01

Background: Although air pollution’s short-term effects are well understood to be marked and preventable, its acute neuropsychological effects have, to our knowledge, not yet been studied. We aim to examine the association between daily variation in traffic-related air pollution and attention. Methods: We conducted a follow-up study from January 2012 to March 2013 in 2,687 school children from 265 classrooms in 39 schools in Barcelona (Catalonia, Spain). We assessed four domains of children’s attention processes every 3 months over four repeated visits providing a total of 10,002 computerized tests on 177 different days using the child Attention Network test (ANT). Ambient daily levels of nitrogen dioxide (NO2) and elemental carbon (EC) in particulate matter <2.5 µm (PM2.5) filters were measured at a fixed air quality background monitoring station and in schools. Results: Daily ambient levels of both NO2 and EC were negatively associated with all attention processes (e.g., children in the bottom quartile of daily exposure to ambient NO2 levels had a 14.8 msecond [95% confidence interval, 11.2, 18.4] faster response time than those in the top quartile, which was equivalent to a 1.1-month [0.84, 1.37] retardation in the natural developmental improvement in response speed with age). Similar findings were observed after adjusting for the average indoor (classroom) levels of pollutants. Associations for EC were similar to those for NO2 and robust to several sensitivity analyses. Conclusions: The short-term association of traffic-related air pollutants with fluctuations in attention adds to the evidence that air pollution may have potential harmful effects on neurodevelopment. See video abstract at, http://links.lww.com/EDE/B158. PMID:27922536

AirMSPI Level 1B2 V006 New Data for the SPEX-PR Campaign

Atmospheric Science Data Center

2018-05-08

... Imager (AirMSPI) Level 1B2 data products for the SPEX engineering flights + Porter Ranch gas leak overflights (SPEX-PR) flight ... AirMSPI data contains all targets acquired during the SPEX engineering flights + Porter Ranch gas leak overflights (SPEX-PR) flight ...

Health risk assessment of air emissions from a municipal solid waste incineration plant--a case study.

PubMed

Cangialosi, Federico; Intini, Gianluca; Liberti, Lorenzo; Notarnicola, Michele; Stellacci, Paolo

2008-01-01

A health risk assessment of long-term emissions of carcinogenic and non-carcinogenic air pollutants has been carried out for the municipal solid waste incinerator (MSWI) of the city of Taranto, Italy. Ground level air concentrations and soil deposition of carcinogenic (Polychlorinated Dibenzo-p-Dioxins/Furans and Cd) and non-carcinogenic (Pb and Hg) pollutants have been estimated using a well documented atmospheric dispersion model. Health risk values for air inhalation, dermal contact, soil and food ingestion have been calculated based on a combination of these concentrations and a matrix of environmental exposure factors. Exposure of the surrounding population has been addressed for different release scenarios based on four pollutants, four exposure pathways and two receptor groups (children and adults). Spatial risk distribution and cancer excess cases projected from plant emissions have been compared with background mortality records. Estimated results based on the MSWI emissions show: (1) individual risks well below maximum acceptable levels, (2) very small incremental cancer risk compared with background level.

Indoor air quality in Portuguese archives: a snapshot on exposure levels.

PubMed

Pinheiro, A C; Viegas, C; Viegas, S; Veríssimo, C; Brandão, J; Macedo, M F

2012-01-01

Indoor air quality recently entered legislation in Portugal. Several parameters must be evaluated and kept within limits in order to obtain a certification for air quality and energy consumption. Certification parameters were analyzed in two Portuguese archives in order to assess indoor air quality both for people attending or working on these premises and for maintenance of a written heritage that must be retained for future generations. Carbon monoxide (CO) and carbon dioxide (CO₂), formaldehyde, and fungal counts were kept within stipulated limits. Relative humidity (RH), volatile organic compounds (VOC), particulate matter (PM₁₀), and ozone (O₃) showed values above legislated levels and justified the implementation of corrective measures. In terms of conservation, studies on the limit values are still needed, but according to the available international guidelines, some of the analyzed parameters such as PM₁₀, O₃, and RH were also above desirable values. Corrective measures were proposed to these institutions. Although this study was only of a short duration, it proved valuable in assessing potential eventual problems and constitutes the first Portuguese indoor air quality assessment taking into consideration both aspects of an archive such as human health and heritage safekeeping.

Occupational exposure to acrylamide in closed system production plants: air levels and biomonitoring.

PubMed

Moorman, William J; Reutman, Susan S; Shaw, Peter B; Blade, Leo Michael; Marlow, David; Vesper, Hubert; Clark, John C; Schrader, Steven M

2012-01-01

The aim of this study was to evaluate biomarkers of acrylamide exposure, including hemoglobin adducts and urinary metabolites in acrylamide production workers. Biomarkers are integrated measures of the internal dose, and it is total acrylamide dose from all routes and sources that may present health risks. Workers from three companies were studied. Workers potentially exposed to acrylamide monomer wore personal breathing-zone air samplers. Air samples and surface-wipe samples were collected and analyzed for acrylamide. General-area air samples were collected in chemical processing units and control rooms. Hemoglobin adducts were isolated from ethylenediamine teraacetic acid (EDTA)-whole blood, and adducts of acrylamide and glycidamide, at the N-terminal valines of hemoglobin, were cleaved from the protein chain by use of a modified Edman reaction. Full work-shift, personal breathing zone, and general-area air samples were collected and analyzed for particulate and acrylamide monomer vapor. The highest general-area concentration of acrylamide vapor was 350 μg/cm(3) in monomer production. Personal breathing zone and general-area concentrations of acrylamide vapor were found to be highest in monomer production operations, and lower levels were in the polymer production operations. Adduct levels varied widely among workers, with the highest in workers in the monomer and polymer production areas. The acrylamide adduct range was 15-1884 pmol/g; glycidamide adducts ranged from 17.8 to 1376 p/mol/g. The highest acrylamide and glycidamide adduct levels were found among monomer production process operators. The primary urinary metabolite N-acetyl-S-(2-carbamoylethyl) cysteine (NACEC) ranged from the limit of detection to 15.4 μg/ml. Correlation of workplace exposure and sentinel health effects is needed to determine and control safe levels of exposure for regulatory standards.

Land cover and air pollution are associated with asthma hospitalisations: A cross-sectional study.

PubMed

Alcock, Ian; White, Mathew; Cherrie, Mark; Wheeler, Benedict; Taylor, Jonathon; McInnes, Rachel; Otte Im Kampe, Eveline; Vardoulakis, Sotiris; Sarran, Christophe; Soyiri, Ireneous; Fleming, Lora

2017-12-01

There is increasing policy interest in the potential for vegetation in urban areas to mitigate harmful effects of air pollution on respiratory health. We aimed to quantify relationships between tree and green space density and asthma-related hospitalisations, and explore how these varied with exposure to background air pollution concentrations. Population standardised asthma hospitalisation rates (1997-2012) for 26,455 urban residential areas of England were merged with area-level data on vegetation and background air pollutant concentrations. We fitted negative binomial regression models using maximum likelihood estimation to obtain estimates of asthma-vegetation relationships at different levels of pollutant exposure. Green space and gardens were associated with reductions in asthma hospitalisation when pollutant exposures were lower but had no significant association when pollutant exposures were higher. In contrast, tree density was associated with reduced asthma hospitalisation when pollutant exposures were higher but had no significant association when pollutant exposures were lower. We found differential effects of natural environments at high and low background pollutant concentrations. These findings can provide evidence for urban planning decisions which aim to leverage health co-benefits from environmental improvements. Copyright © 2017 Elsevier Ltd. All rights reserved.

23. Station Compressor Room 1 with Air Compressors and Accumulator ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

23. Station Compressor Room 1 with Air Compressors and Accumulator Tanks, view to the south. One of the two large station air compressor units used for depressing the draft tube water level is visible atop a concrete pedestal on the left side of photograph (the second identical compressor is located in an adjacent room). Two of the six station air accumulator tanks are visible in the background. The smaller station service air compressor is visible in right foreground of the photograph was installed in the early 1980s, and replaced the original station service air compressor. - Washington Water Power Clark Fork River Noxon Rapids Hydroelectric Development, Powerhouse, South bank of Clark Fork River at Noxon Rapids, Noxon, Sanders County, MT

Comparison of Indoor Air Quality Management Strategies between the School and District Levels in New York State

ERIC Educational Resources Information Center

Lin, Shao; Kielb, Christine L.; Reddy, Amanda L.; Chapman, Bonnie R.; Hwang, Syni-An

2012-01-01

Background: Good school indoor air quality (IAQ) can affect the health and functioning of school occupants. Thus, it is important to assess the degree to which schools and districts employ strategies to ensure good IAQ management. We examined and compared the patterns of IAQ management strategies between public elementary schools and their school…

Notification: Background Investigation Services EPA’s Efforts to Incorporate Environmental Justice Into Clean Air Act Inspections for Air Toxics

EPA Pesticide Factsheets

Project #OPE-FY14-0017, March 7, 2014. The OIG plans to begin the preliminary research phase of an evaluation of the EPA's efforts to incorporate environmental justice into Clean Air Act (CAA) inspections for air toxics.

Development of Atmospheric Air 85Kr Monitoring Methodology on the Territory of the USSR

NASA Astrophysics Data System (ADS)

Pakhomov, Sergei; Dubasov, Yury

2014-05-01

atmospheric air was close to background level during monitoring. But in Lipetsk; Orsk; Nizhni Tagil and Temirtau 10-20% excess of background level was systematically observed. In Chelyabinsk concentration of 85Kr steadily exceeded this level by 2-3 times, and incidentally exceeded it for order. Generally, during this period about 1500 values of concentration 85Kr were obtained. Actually, the large-scale monitoring system of atmospheric 85Kr with a binding of sampling points to 14 air-separating plants covered the territory 1000 x 3000 km was created. The developed method of 85Kr activity measurement was successfully applied also when carrying out expedition works in Northern Atlantic during the period from 1987 to 1994 with use o ZIF-1000 cryogenic installation for sampling, which initially was intended for liquid nitrogen manufacturing at the ship. Generally, 80 measurements of 85Kr concentration were obtained using this method. It was determined, that the average concentration of 85Kr in atmospheric air in the open regions of the Atlantic Ocean, were close to background level during monitoring. The concentrations of 85Kr steadily exceeded this level by 2-3 times in English Channel, and incidentally exceeded it in tens times.

Combining the AIRS, CrIS and IASI Radiance Records for Climate Level Retrievals

NASA Astrophysics Data System (ADS)

Strow, L. L.

2016-12-01

The AIRS record is now 14+ years long, and with the addition of CrIS should provide a 30+ year long hyperspectral radiance record that can be supplemented with another two times in the diurnal cycle with IASI starting in 2007. The stability of these sensors can be established by comparisons to CO2 variability and to tropical sea surface temperature trends. At present the observed stabilities are much better than climate requirements of 0.01/year. SNO observations indicate radiometric agreement among these sensors of 0.1 - 0.3K before any empirical adjustments. A 1-year set of SNO overlaps have statistical uncertainties of less than 0.01K between these three sensors. Moreover, we show that IASI can be used as a transfer standard between AIRS and CrIS (or between CrIS-1 and CrIS-2) should there be a gap in overlap of sensors in the PM orbit. We have done these SNO comparisons by converting AIRS and IASI spectral to the CrIS instrument lineshape (ILS). Achieving climate quality retrievals, trends, and anomalies of temperature and humidity is non-trivial and requires error characterization (not validation) that to date has not been done with single-footprint hyperspectral sensor retrievals. We suggest that the infrared hyperspectral community utilize a common ILS radiance product as a first-step in achieving climate-quality retrievals in order to remove uncertainties in differential instrument sensitivies and in different forward radiative transfer models. We propose a very different approach for Level 3 (climate) products where anomalies and trends (one of the main products of interest to the climate community) are derived directly from Level 3 radiance products, giving far superior error traceability and retrieval regularization in the vertical. Tempertature and humidity trends and anomalies for 14-years of AIRS will be presented and compared to those provided by ERA-Interim, AIRS Level3 data, and microwave sensors. A significant advantage of this approach, which

Air to air views of Endeavour, Orbiter Vehicle (OV) 105

NASA Image and Video Library

1959-01-01

Air to air views of Endeavour, Orbiter Vehicle (OV) 105, transported via the Shuttle Carrier Aircraft (SCA), NASA 911, on its way to KSC, 05-06-91. JSC with Clear Creek and Egret Bay Blvd in the foreground and Clear Lake and Galveston Bay in the background

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

Determination of Selected Chemical Levels in Room Air and on Surfaces after the Use of Cartridge- and Tank-Based E-Vapor Products or Conventional Cigarettes.

PubMed

Liu, Jianmin; Liang, Qiwei; Oldham, Michael J; Rostami, Ali A; Wagner, Karl A; Gillman, I Gene; Patel, Piyush; Savioz, Rebecca; Sarkar, Mohamadi

2017-08-28

There is an ongoing debate regarding the potential of secondhand exposure of non-users to various chemicals from use of e-vapor products (EVPs). Room air levels of 34 chemicals (nicotine, propylene glycol (PG), glycerol, 15 carbonyl chemicals, 12 volatile organic chemicals (VOCs), and four selected trace elements) were measured where EVPs and cigarettes were used by n = 37 healthy adult tobacco users in an exposure chamber. The products used were MarkTen ® 2.5% Classic (Group I), a Prototype GreenSmoke ® 2.4% (Group II), Ego-T ® Tank with subjects' own e-liquids (Group III) and subjects' own conventional cigarettes (Group IV). Products were used under controlled conditions and 4-h ad libitum use. Background (without subjects) and baseline levels (with subjects) were measured. Cumulative 4-h. levels of nicotine, PG and glycerol measured were several-fold below the time-weighted average limits used in workplace exposure evaluation. Most the other chemicals (>75%) were at or below the limit of quantification during EVP use. Significant levels of chemicals (17 out of 34) were observed in Group IV. Overall, our results indicate that under the study conditions with the products tested, cumulative room air levels of the selected chemicals measured over 4-h were relatively small and were several-fold below the current occupational regulatory and consensus limits.

Background levels of some major, trace, and rare earth elements in indigenous plant species growing in Norway and the influence of soil acidification, soil parent material, and seasonal variation on these levels.

PubMed

Gjengedal, Elin; Martinsen, Thomas; Steinnes, Eiliv

2015-06-01

Baseline levels of 43 elements, including major, trace, and rare earth elements (REEs) in several native plant species growing in boreal and alpine areas, are presented. Focus is placed on species metal levels at different soil conditions, temporal variations in plant tissue metal concentrations, and interspecies variation in metal concentrations. Vegetation samples were collected at Sogndal, a pristine site in western Norway, and at Risdalsheia, an acidified site in southernmost Norway. Metal concentrations in the different species sampled in western Norway are compared with relevant literature data from Norway, Finland, and northwest Russia, assumed to represent natural conditions. Except for aluminium (Al) and macronutrients, the levels of metals were generally lower in western Norway than in southern Norway and may be considered close to natural background levels. In southern Norway, the levels of cadmium (Cd) and lead (Pb) in particular appear to be affected by air pollution, either by direct atmospheric supply or through soil acidification. Levels of some elements show considerable variability between as well as within plant species. Calcium (Ca), magnesium (Mg), and potassium (K) are higher in most species at Sogndal compared to Risdalsheia, despite increased extractable concentrations in surface soil in the south, probably attributed to different buffer mechanisms in surface soil. Antagonism on plant uptake is suggested between Ca, Mg, and K on one hand and Al on the other. Tolerance among calcifuges to acid conditions and a particular ability to detoxify or avoid uptake of Al ions are noticeable for Vaccinium vitis-idaea.

Do Individual and Neighborhood Characteristics Influence Perceived Air Quality?

PubMed Central

Deguen, Séverine; Padilla, Manon; Kihal-Talantikite, Wahida

2017-01-01

Background: Despite improvements, air pollution still remains a major public health issue. Numerous epidemiological studies have demonstrated the adverse health effects of air pollution exposure based on modeled measures, but only a few have considered the health impact of perceived air quality. Improving our knowledge of individual perceptions is crucial to defining targeted actions and promoting appropriate intervention measures. Our objective is to investigate the relationship between subjective and objective measures of air pollution and to focus on how individual characteristics combined with the neighborhood socioeconomic deprivation index, measured at a fine spatial scale, may or may not alter this relationship. Materials and Methods: The subjective measures of air quality reported by a sample of Lyon residents were collected via an individual questionnaire. The objective measures of air pollution were modeled by the local air quality monitoring network of the Rhône-Alpes region at census block level. We used a socioeconomic deprivation index to capture the different socioeconomic dimensions at census block level. The statistical analysis was structured in two steps: (1) identification of individual determinants of the subjective measures of air quality using multiple correspondence analysis followed by hierarchical clustering; (2) identification of individual and contextual characteristics that may alter the relationship between the objective and subjective measures of air pollution. Results: Among the youngest and the middle aged population (ages 30 to 59), consistent results between level of satisfaction, perceived air quality and objective measures of air pollution were found whatever the individual characteristics of the population. It is less clear among the oldest population: globally no significant difference between the NO2 concentrations and the level of satisfaction was observed. Conclusions: We found a significant relationship between the

Do Individual and Neighborhood Characteristics Influence Perceived Air Quality?

PubMed

Deguen, Séverine; Padilla, Manon; Padilla, Cindy; Kihal-Talantikite, Wahida

2017-12-12

Background : Despite improvements, air pollution still remains a major public health issue. Numerous epidemiological studies have demonstrated the adverse health effects of air pollution exposure based on modeled measures, but only a few have considered the health impact of perceived air quality. Improving our knowledge of individual perceptions is crucial to defining targeted actions and promoting appropriate intervention measures. Our objective is to investigate the relationship between subjective and objective measures of air pollution and to focus on how individual characteristics combined with the neighborhood socioeconomic deprivation index, measured at a fine spatial scale, may or may not alter this relationship. Materials and Methods : The subjective measures of air quality reported by a sample of Lyon residents were collected via an individual questionnaire. The objective measures of air pollution were modeled by the local air quality monitoring network of the Rhône-Alpes region at census block level. We used a socioeconomic deprivation index to capture the different socioeconomic dimensions at census block level. The statistical analysis was structured in two steps: (1) identification of individual determinants of the subjective measures of air quality using multiple correspondence analysis followed by hierarchical clustering; (2) identification of individual and contextual characteristics that may alter the relationship between the objective and subjective measures of air pollution. Results : Among the youngest and the middle aged population (ages 30 to 59), consistent results between level of satisfaction, perceived air quality and objective measures of air pollution were found whatever the individual characteristics of the population. It is less clear among the oldest population: globally no significant difference between the NO₂ concentrations and the level of satisfaction was observed. Conclusion s : We found a significant relationship between the

Data Assimilation and Regional Forecasts Using Atmospheric InfraRed Sounder (AIRS) Profiles

NASA Technical Reports Server (NTRS)

Chou, Shih-Hung; Zavodsky, Bradley; Jedlovec, Gary

2009-01-01

In data sparse regions, remotely-sensed observations can be used to improve analyses, which in turn should lead to better forecasts. One such source comes from the Atmospheric Infrared Sounder (AIRS), which together with the Advanced Microwave Sounding Unit (AMSU), provides temperature and moisture profiles with an accuracy comparable to that of radiosondes. The purpose of this paper is to describe a procedure to optimally assimilate AIRS thermodynamic profiles--obtained from the version 5.0 Earth Observing System (EOS) science team retrieval algorithm-into a regional configuration of the Weather Research and Forecasting (WRF) model using WRF-Var. The paper focuses on development of background error covariances for the regional domain and background field type, a methodology for ingesting AIRS profiles as separate over-land and over-water retrievals with different error characteristics, and utilization of level-by-level quality indicators to select only the highest quality data. The assessment of the impact of the AIRS profiles on WRF-Var analyses will focus on intelligent use of the quality indicators, optimized tuning of the WRF-Var, and comparison of analysis soundings to radiosondes. The analyses will be used to conduct a month-long series of regional forecasts over the continental U.S. The long-tern1 impact of AIRS profiles on forecast will be assessed against verifying radiosonde and stage IV precipitation data.

Data Assimilation and Regional Forecasts using Atmospheric InfraRed Sounder (AIRS) Profiles

NASA Technical Reports Server (NTRS)

Zabodsky, Brad; Chou, Shih-Hung; Jedlovec, Gary J.

2009-01-01

In data sparse regions, remotely-sensed observations can be used to improve analyses, which in turn should lead to better forecasts. One such source comes from the Atmospheric Infrared Sounder (AIRS), which, together with the Advanced Microwave Sounding Unit (AMSU), provides temperature and moisture profiles with an accuracy comparable to that of radionsondes. The purpose of this poster is to describe a procedure to optimally assimilate AIRS thermodynamic profiles, obtained from the version 5.0 Earth Observing System (EOS) science team retrieval algorithm, into a regional configuration of the Weather Research and Forecasting (WRF) model using WRF-Var. The poster focuses on development of background error covariances for the regional domain and background field type, a methodology for ingesting AIRS profiles as separate over-land and over-water retrievals with different error characteristics, and utilization of level-by-level quality indicators to select only the highest quality data. The assessment of the impact of the AIRS profiles on WRF-Var analyses will focus on intelligent use of the quality indicators, optimized tuning of the WRF-Var, and comparison of analysis soundings to radiosondes. The analyses are used to conduct a month-long series of regional forecasts over the continental U.S. The long-term impact of AIRS profiles on forecast will be assessed against NAM analyses and stage IV precipitation data.

Air pollution, health and social deprivation: A fine-scale risk assessment.

PubMed

Morelli, Xavier; Rieux, Camille; Cyrys, Josef; Forsberg, Bertil; Slama, Rémy

2016-05-01

Risk assessment studies often ignore within-city variations of air pollutants. Our objective was to quantify the risk associated with fine particulate matter (PM2.5) exposure in 2 urban areas using fine-scale air pollution modeling and to characterize how this risk varied according to social deprivation. In Grenoble and Lyon areas (0.4 and 1.2 million inhabitants, respectively) in 2012, PM2.5 exposure was estimated on a 10×10m grid by coupling a dispersion model to population density. Outcomes were mortality, lung cancer and term low birth weight incidences. Cases attributable to air pollution were estimated overall and stratifying areas according to the European Deprivation Index (EDI), taking 10µg/m(3) yearly average as reference (counterfactual) level. Estimations were repeated assuming spatial homogeneity of air pollutants within urban area. Median PM2.5 levels were 18.1 and 19.6μg/m(3) in Grenoble and Lyon urban areas, respectively, corresponding to 114 (5.1% of total, 95% confidence interval, CI, 3.2-7.0%) and 491 non-accidental deaths (6.0% of total, 95% CI 3.7-8.3%) attributable to long-term exposure to PM2.5, respectively. Attributable term low birth weight cases represented 23.6% of total cases (9.0-37.1%) in Grenoble and 27.6% of cases (10.7-42.6%) in Lyon. In Grenoble, 6.8% of incident lung cancer cases were attributable to air pollution (95% CI 3.1-10.1%). Risk was lower by 8 to 20% when estimating exposure through background stations. Risk was highest in neighborhoods with intermediate to higher social deprivation. Risk assessment studies relying on background stations to estimate air pollution levels may underestimate the attributable risk. Copyright © 2016 Elsevier Inc. All rights reserved.

Current Background Noise Sources and Levels in the NASA Ames 40- by 80-Foot Wind Tunnel: A Status Report

NASA Technical Reports Server (NTRS)

Allen, Christopher S.; Jaeger, Stephen; Soderman, Paul; Koga, Dennis (Technical Monitor)

1999-01-01

Background noise measurements were made of the acoustic environment in the National Full-Scale Aerodynamics Complex 40- by 80-Foot Wind Tunnel (40x80) at NASA Ames Research Center. The measurements were acquired subsequent to the 40x80 Aeroacoustic Modernization Project, which was undertaken to improve the anechoic characteristics of the 40x80's closed test section as well as reduce the levels of background noise in the facility. The resulting 40x80 anechoic environment was described by Soderman et. al., and the current paper describes the resulting 40x80 background noise, discusses the sources of the noise, and draws comparisons to previous 40x80 background noise levels measurements. At low wind speeds or low frequencies, the 40x80 background noise is dominated by the fan drive system. To obtain the lowest fan drive noise for a given tunnel condition, it is possible in the 40x80 to reduce the fans' rotational speed and adjust the fans' blade pitch, as described by Schmidtz et. al. This idea is not new, but has now been operationally implemented with modifications for increased power at low rotational speeds. At low to mid-frequencies and at higher wind speeds, the dominant noise mechanism was thought to be caused by the surface interface of the previous test section floor acoustic lining. In order to reduce this noise mechanism, the new test section floor lining was designed to resist the pumping of flow in and out of the space between the grating slats required to support heavy equipment. In addition, the lining/flow interface over the entire test section was designed to be smoother and quieter than the previous design. At high wind speeds or high frequencies, the dominant source of background noise in the 40x80 is believed to be caused by the response of the in-flow microphone probes (required by the nature of the closed test section) to the fluctuations in the freestream flow. The resulting background noise levels are also different for probes of various

Traffic and outdoor air pollution levels near residences and poorly controlled asthma in adults.

PubMed

Meng, Ying-Ying; Wilhelm, Michelle; Rull, Rudolph P; English, Paul; Ritz, Beate

2007-05-01

Air pollution may exacerbate asthma. To investigate associations between traffic and outdoor air pollution levels near residences and poorly controlled asthma among adults diagnosed as having asthma in Los Angeles and San Diego counties, California. We estimated traffic density within 500 ft of 2001 California Health Interview Survey respondents' reported residential cross-street intersections. Additionally, we assigned annual average concentrations of ozone, nitrogen dioxide, particulate matter 2.5 and 10 micrometers or less in diameter, and carbon monoxide measured at government monitoring stations within a 5-mile radius of the reported residential cross-street intersections. We observed a 2-fold increase in poorly controlled asthma (odds ratio [OR], 2.11; 95% confidence interval [CI], 1.38-3.23) among asthmatic adults in the highest quintile of traffic density after adjusting for age, sex, race, and poverty. Similar increases were seen for nonelderly adults, men, and women, although associations seemed strongest in elderly adults (OR, 3.00; 95% CI, 1.13-7.91). Ozone exposures were associated with poorly controlled asthma among elderly adults (OR, 1.70; 95% CI, 0.91-3.18 per 1 pphm) and men (OR, 1.76; 95% CI, 1.05-2.94 per 1 pphm), whereas particulate matter 10 micrometers or less seemed to affect primarily women (OR, 2.06; 95% CI, 1.17-3.61), even at levels below the national air quality standard. Heavy traffic and high air pollution levels near residences are associated with poorly controlled asthma.

AirMSPI Level 1B2 V006 New Data for NASA’s RADEX Campaign

Atmospheric Science Data Center

2018-05-09

AirMSPI Level 1B2 V006 New Data for NASA’s RADEX Campaign RADEX Wednesday, May 16, 2018 The NASA Langley Atmospheric Science Data Center (ASDC) and Jet Propulsion ... flight campaign.   AirMSPI flies in the nose of NASA's high-altitude ER-2 aircraft. The instrument was built by JPL and the ...

AirMSPI Level 1B2 V006 New Data for NASA/SRON ACEPOL Campaign

Atmospheric Science Data Center

2018-05-07

AirMSPI Level 1B2 V006 New Data for NASA/SRON ACEPOL Campaign ACEPOL Wednesday, April 18, 2018 The NASA Langley Atmospheric Sciences Data Center (ASDC) and Jet Propulsion ... flight campaign.   AirMSPI flies in the nose of NASA's high-altitude ER-2 aircraft. The instrument was built by JPL and the ...

Search for tachyons associated with extensive air showers in the ground level cosmic radiation

NASA Technical Reports Server (NTRS)

Masjed, H. F.; Ashton, F.

1985-01-01

Events detected in a shielded plastic scintillation counter occurring in the 26 microsec preceding the arrival of an extensive air shower at ground level with local electron density or = 20 m to the -2 power and the 240 microsec after its arrival have been studied. No significant excess of events (tachyons) arriving in the early time domain have been observed in a sample of 11,585 air shower triggers.

Role of persistent low-level clouds in mitigating air quality impacts of wintertime cold pool conditions

NASA Astrophysics Data System (ADS)

VanReken, Timothy M.; Dhammapala, Ranil S.; Jobson, B. Thomas; Bottenus, Courtney L.; VanderSchelden, Graham S.; Kaspari, Susan D.; Gao, Zhongming; Zhu, Qiurui; Lamb, Brian K.; Liu, Heping; Johnston, Jeff

2017-04-01

The Yakima Air Wintertime Nitrate Study (YAWNS) was conducted in January 2013 to investigate the drivers of elevated levels of fine particulate matter (PM2.5) frequently present in the region during winter stagnation periods. An extended stagnation period occurred during the study. For the first four days of the event, skies were clear and the strong diel variation in air pollution patterns were consistent with the expected effects of strong low-level nighttime temperature inversions with moderate mixing during daylight hours. Later in the event a low-level cloud layer formed that persisted over the Yakima Valley for the next seven days while regional conditions remained stagnant. Coincident with the onset of cloud, the levels of all measured primary pollutants, including CO2, CO, NOx, particle number concentration, and black carbon, dropped dramatically and remained low with negligible diel variation for as long as the cloud layer was present. The observed patterns for these air pollutants are consistent with decreased stability and enhanced mixing associated with the cloud-topped boundary layer. Interestingly, levels of secondary pollutants, most notably particulate ammonium nitrate, did not exhibit the same decline. This difference may be due to shifts in the chemical production of secondary pollutants during cloudy conditions, or may merely reflect a further influence of mixing. The results imply that the best strategies for managing wintertime air quality during episodes of persistent cloud are likely different from those needed during clear-sky stagnation events.

Benzene levels in ambient air and breath of smokers and nonsmokers in urban and pristine environments

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

Wester, R.C.; Maibach, H.I.; Gruenke, L.D.

Benzene levels in human breath and in ambient air were compared in the urban area of San Francisco (SF) and in a more remote coastal pristine setting of Stinson Beach, Calif. (SB). Benzene analysis was done by gas chromatography-mass spectroscopy (GC-MS). Ambient benzene levels were sevenfold higher in SF (2.6 +/- 1.3 ppb, n = 25) than SB (0.38 +/- 0.39 ppb, n = 21). In SF, benzene in smokers' breath (6.8 +/- 3.0 ppb) was greater than in nonsmokers' breath (2.5 +/- 0.8 ppb) and smokers' ambient air (3.3 +/- 0.8 ppb). In SB the same pattern was observed:more » benzene in smokers' breath was higher than in nonsmokers' breath and ambient air. Benzene in SF nonsmokers' breath was greater than in SB nonsmokers' breath. Marijuana-only smokers had benzene breath levels between those of smokers and nonsmokers. There was little correlation between benzene in breath and number of cigarettes smoked, or with other benzene exposures such as diet. Of special interest was the finding that benzene in breath of SF nonsmokers (2.5 +/- 0.8 ppb) was greater than that in nonsmokers ambient air (1.4 +/- 0.1 ppb). The same was true in SB, where benzene in nonsmokers breath was greater than ambient air (1.8 +/- 0.2 ppb versus 1.0 +/- 0.1 ppb on d 1 and 1.3 +/- 0.3 ppb versus 0.23 +/- 0.18 ppb on d 2). This suggests an additional source of benzene other than outdoor ambient air.« less

Decreasing airborne contamination levels in high-risk hospital areas using a novel mobile air-treatment unit.

PubMed

Bergeron, V; Reboux, G; Poirot, J L; Laudinet, N

2007-10-01

To evaluate the performance of a new mobile air-treatment unit that uses nonthermal-plasma reactors for lowering the airborne bioburden in critical hospital environments and reducing the risk of nosocomial infection due to opportunistic airborne pathogens, such as Aspergillus fumigatus. Tests were conducted in 2 different high-risk hospital areas: an operating room under simulated conditions and rooms hosting patients in a pediatric hematology ward. Operating room testing provided performance evaluations of removal rates for airborne contamination (ie, particles larger than 0.5 microm) and overall lowering of the airborne bioburden (ie, colony-forming units of total mesophilic flora and fungal flora per cubic meter of air). In the hematology service, opportunistic and nonpathogenic airborne fungal levels in a patient's room equipped with an air-treatment unit were compared to those in a control room. In an operating room with a volume of 118 m(3), the time required to lower the concentration of airborne particles larger than 0.5 microm by 90% was decreased from 12 minutes with the existing high-efficiency particulate air filtration system to less than 2 minutes with the units tested, with a 2-log decrease in the steady-state levels of such particles (P<.01). Concurrently, total airborne mesophilic flora concentrations dropped by a factor of 2, and the concentrations of fungal species were reduced to undetectable levels (P<.01). The 12-day test period in the hematology ward revealed a significant reduction in airborne fungus levels (P<.01), with average reductions of 75% for opportunistic species and 82% for nonpathogenic species. Our data indicate that the mobile, nonthermal-plasma air treatment unit tested in this study can rapidly reduce the levels of airborne particles and significantly lower the airborne bioburden in high-risk hospital environments.

Background concentrations of polychlorinated dibenzo-p-dioxins, dibenzofurans, and biphenyls in the global oceanic atmosphere.

PubMed

Morales, Laura; Dachs, Jordi; González-Gaya, Belén; Hernán, Gema; Abalos, Manuela; Abad, Esteban

2014-09-02

The remote oceans are among the most pristine environments in the world, away from sources of anthropogenic persistent organic pollutants (POP), but nevertheless recipients of atmospheric deposition of POPs that have undergone long-range atmospheric transport (LRAT). In this work, the background occurrence of gas and aerosol phase polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin like polychlorinated biphenyls (dl-PCB) is evaluated for the first time in the atmosphere of the tropical and subtropical Atlantic, Pacific, and Indian oceans. Thirty-nine air samples were collected during the eight-month Malaspina circumnavigation cruise onboard the R/V Hespérides. The background levels of dioxins and dl-PCBs remained very low and in many cases very close to or below the limit of detection. Expectedly, the levels of PCBs were higher than dioxins, PCB#118 being the most abundant compound. In the particular case of dioxins, octachlorodibenzo-p-dioxin (OCDD) was the most abundant PCDD/F congener. Distribution of dl-PCB is dominated by the gas phase, while for PCDD/F the aerosol phase concentrations were higher, particularly for the more hydrophobic congeners. The Atlantic Ocean presented on average the highest PCDD/F and dl-PCB concentrations, being lower in the southern hemisphere. The assessment of air mass back trajectories show a clear influence of continental source regions, and lower concentrations when the air mass has an oceanic origin. In addition, the samples affected by an oceanic air mass are characterized by a lower contribution of the less chlorinated dioxins in comparison with the furans, consistent with the reported higher reaction rate constants of dibenzo-p-dioxins with OH radicals than those of dibenzofurans. The total dry atmospheric deposition of aerosol-bound ∑PCDD/F and ∑dl-PCB to the global oceans was estimated to be 354 and 896 kg/year, respectively.

Effect of public transport strikes on air pollution levels in Barcelona (Spain).

PubMed

Basagaña, Xavier; Triguero-Mas, Margarita; Agis, David; Pérez, Noemí; Reche, Cristina; Alastuey, Andrés; Querol, Xavier

2018-01-01

Public transport strikes can lead to an increase of the number of private vehicle trips, which in turn can increase air pollution levels. We aimed to estimate the change in air pollution concentrations during public transport strikes in the city of Barcelona (Spain). Data on strikes of the metro, train or bus systems were collected from government records (2005-2016). We collected daily concentrations of NOx; particulate matter with an aerodynamic diameter smaller than 10μm (PM10), 2.5μm (PM2.5), and 1μm (PM1); particle number concentration (N); black carbon (BC) and CO from research and official monitoring stations. We fitted linear regression models for each pollutant with the strike indicator as an independent variable, and models were adjusted for day of the week, month, year, and holiday periods. During the study period, there were 208days affected by a strike of the metro (28), train (106) or bus (91) systems. Half of the strikes were partial, most of them were single-day strikes, there was little overlap between strikes of the different transport systems, and all strikes had to comply with mandatory minimal services. When pooling all types of strikes, NOx and BC showed higher levels during strike days in comparison with non-strike days (increase between 4.1% and 7.7%, with higher increases for NO). The increases in these concentrations were more evident during full day and multiday metro strikes. In conclusion, alterations in public transport have consequences on air quality. This highlights the importance of public transport in reducing air pollution concentrations in cities. Copyright © 2017 Elsevier B.V. All rights reserved.

BAERLIN2014 - the influence of land surface types on and the horizontal heterogeneity of air pollutant levels in Berlin

NASA Astrophysics Data System (ADS)

Bonn, Boris; von Schneidemesser, Erika; Andrich, Dorota; Quedenau, Jörn; Gerwig, Holger; Lüdecke, Anja; Kura, Jürgen; Pietsch, Axel; Ehlers, Christian; Klemp, Dieter; Kofahl, Claudia; Nothard, Rainer; Kerschbaumer, Andreas; Junkermann, Wolfgang; Grote, Rüdiger; Pohl, Tobias; Weber, Konradin; Lode, Birgit; Schönberger, Philipp; Churkina, Galina; Butler, Tim M.; Lawrence, Mark G.

2016-06-01

Urban air quality and human health are among the key aspects of future urban planning. In order to address pollutants such as ozone and particulate matter, efforts need to be made to quantify and reduce their concentrations. One important aspect in understanding urban air quality is the influence of urban vegetation which may act as both emitter and sink for trace gases and aerosol particles. In this context, the "Berlin Air quality and Ecosystem Research: Local and long-range Impact of anthropogenic and Natural hydrocarbons 2014" (BAERLIN2014) campaign was conducted between 2 June and 29 August in the metropolitan area of Berlin and Brandenburg, Germany. The predominant goals of the campaign were (1) the characterization of urban gaseous and particulate pollution and its attribution to anthropogenic and natural sources in the region of interest, especially considering the connection between biogenic volatile organic compounds and particulates and ozone; (2) the quantification of the impact of urban vegetation on organic trace gas levels and the presence of oxidants such as ozone; and (3) to explain the local heterogeneity of pollutants by defining the distribution of sources and sinks relevant for the interpretation of model simulations. In order to do so, the campaign included stationary measurements at urban background station and mobile observations carried out from bicycle, van and airborne platforms. This paper provides an overview of the mobile measurements (Mobile BAERLIN2014) and general conclusions drawn from the analysis. Bicycle measurements showed micro-scale variations of temperature and particulate matter, displaying a substantial reduction of mean temperatures and particulate levels in the proximity of vegetated areas compared to typical urban residential area (background) measurements. Van measurements extended the area covered by bicycle observations and included continuous measurements of O3, NOx, CO, CO2 and point-wise measurement of volatile

Application of nonparametric regression methods to study the relationship between NO2 concentrations and local wind direction and speed at background sites.

PubMed

Donnelly, Aoife; Misstear, Bruce; Broderick, Brian

2011-02-15

Background concentrations of nitrogen dioxide (NO(2)) are not constant but vary temporally and spatially. The current paper presents a powerful tool for the quantification of the effects of wind direction and wind speed on background NO(2) concentrations, particularly in cases where monitoring data are limited. In contrast to previous studies which applied similar methods to sites directly affected by local pollution sources, the current study focuses on background sites with the aim of improving methods for predicting background concentrations adopted in air quality modelling studies. The relationship between measured NO(2) concentration in air at three such sites in Ireland and locally measured wind direction has been quantified using nonparametric regression methods. The major aim was to analyse a method for quantifying the effects of local wind direction on background levels of NO(2) in Ireland. The method was expanded to include wind speed as an added predictor variable. A Gaussian kernel function is used in the analysis and circular statistics employed for the wind direction variable. Wind direction and wind speed were both found to have a statistically significant effect on background levels of NO(2) at all three sites. Frequently environmental impact assessments are based on short term baseline monitoring producing a limited dataset. The presented non-parametric regression methods, in contrast to the frequently used methods such as binning of the data, allow concentrations for missing data pairs to be estimated and distinction between spurious and true peaks in concentrations to be made. The methods were found to provide a realistic estimation of long term concentration variation with wind direction and speed, even for cases where the data set is limited. Accurate identification of the actual variation at each location and causative factors could be made, thus supporting the improved definition of background concentrations for use in air quality modelling

An accurate derivation of the air dose-rate and the deposition concentration distribution by aerial monitoring in a low level contaminated area

NASA Astrophysics Data System (ADS)

Nishizawa, Yukiyasu; Sugita, Takeshi; Sanada, Yukihisa; Torii, Tatsuo

2015-04-01

Since 2011, MEXT (Ministry of Education, Culture, Sports, Science and Technology, Japan) have been conducting aerial monitoring to investigate the distribution of radioactive cesium dispersed into the atmosphere after the accident at the Fukushima Dai-ichi Nuclear Power Plant (FDNPP), Tokyo Electric Power Company. Distribution maps of the air dose-rate at 1 m above the ground and the radioactive cesium deposition concentration on the ground are prepared using spectrum obtained by aerial monitoring. The radioactive cesium deposition is derived from its dose rate, which is calculated by excluding the dose rate of the background radiation due to natural radionuclides from the air dose-rate at 1 m above the ground. The first step of the current method of calculating the dose rate due to natural radionuclides is calculate the ratio of the total count rate of areas where no radioactive cesium is detected and the count rate of regions with energy levels of 1,400 keV or higher (BG-Index). Next, calculate the air dose rate of radioactive cesium by multiplying the BG-Index and the integrated count rate of 1,400 keV or higher for the area where the radioactive cesium is distributed. In high dose-rate areas, however, the count rate of the 1,365-keV peak of Cs-134, though small, is included in the integrated count rate of 1,400 keV or higher, which could cause an overestimation of the air dose rate of natural radionuclides. We developed a method for accurately evaluating the distribution maps of natural air dose-rate by excluding the effect of radioactive cesium, even in contaminated areas, and obtained the accurate air dose-rate map attributed the radioactive cesium deposition on the ground. Furthermore, the natural dose-rate distribution throughout Japan has been obtained by this method.

Air Pollution and Serum Glucose Levels

PubMed Central

Sade, Maayan Yitshak; Kloog, Itai; Liberty, Idit F.; Katra, Itzhak; Novack, Lena; Novack, Victor

2015-01-01

Abstract Recent studies demonstrated an adverse effect of chronic exposure to air pollution (AP) on metabolic syndrome and its components. In a population-based study, we investigated the association between exposure to ambient AP and serum glucose (SG), among subjects with normal glucose, impaired fasting glucose (IFG), and diabetes mellitus (DM). We included 1,063,887 SG tests performed in 131,882 subjects (years 2001–2012). Exposure data included daily levels of SO2, NO2 and other pollutants of industrial, traffic, and nonanthropogenic sources. Demographical, clinical, and medications purchase data were assessed. Log-transformed SG levels were analyzed by linear mixed models adjusted for seasonal variables and personal characteristics. SG increases (%increase [95% CI]), among subjects with normal glucose, IFG, and DM, respectively, were associated with 6.36 ppb increase of NO2 measured 24 to 72 hours before the test (0.40% [0.31%; 0.50%], 0.56% [0.40%; 0.71%], and 1.08% [0.86%; 1.29%]); and with 1.17 ppb increase of SO2 measured 24 hours before the test (0.29% [0.22%; 0.36%], 0.20% [0.10%; 0.31%], and 0.33% [0.14%; 0.52%]). Among DM population, weakest association was observed among patients treated with Metformin (0.56% increase in SG [0.18%; 0.95%]). In conclusion, NO2 and SO2 exposure is associated with small but significantly increased levels of SG. Although DM patients were found to be more susceptible to the AP induced SG variations, Metformin treatment seem to have a protective effect. Given the chronic lifetime exposure to AP and the broad coverage of the population, even small associations such as those found in our study can be associated with detrimental health effects and may have profound public health implications. PMID:26166095

Geochemistry of regional background aerosols in the Western Mediterranean

NASA Astrophysics Data System (ADS)

Pey, J.; Pérez, N.; Castillo, S.; Viana, M.; Moreno, T.; Pandolfi, M.; López-Sebastián, J. M.; Alastuey, A.; Querol, X.

2009-11-01

The chemical composition of regional background aerosols, and the time variability and sources in the Western Mediterranean are interpreted in this study. To this end 2002-2007 PM speciation data from an European Supersite for Atmospheric Aerosol Research (Montseny, MSY, located 40 km NNE of Barcelona in NE Spain) were evaluated, with these data being considered representative of regional background aerosols in the Western Mediterranean Basin. The mean PM 10, PM 2.5 and PM 1 levels at MSY during 2002-2007 were 16, 14 and 11 µg/m 3, respectively. After compiling data on regional background PM speciation from Europe to compare our data, it is evidenced that the Western Mediterranean aerosol is characterised by higher concentrations of crustal material but lower levels of OM + EC and ammonium nitrate than at central European sites. Relatively high PM 2.5 concentrations due to the transport of anthropogenic aerosols (mostly carbonaceous and sulphate) from populated coastal areas were recorded, especially during winter anticyclonic episodes and summer midday PM highs (the latter associated with the transport of the breeze and the expansion of the mixing layer). Source apportionment analyses indicated that the major contributors to PM 2.5 and PM 10 were secondary sulphate, secondary nitrate and crustal material, whereas the higher load of the anthropogenic component in PM 2.5 reflects the influence of regional (traffic and industrial) emissions. Levels of mineral, sulphate, sea spray and carbonaceous aerosols were higher in summer, whereas nitrate levels and Cl/Na were higher in winter. A considerably high OC/EC ratio (14 in summer, 10 in winter) was detected, which could be due to a combination of high biogenic emissions of secondary organic aerosol, SOA precursors, ozone levels and insolation, and intensive recirculation of aged air masses. Compared with more locally derived crustal geological dusts, African dust intrusions introduce relatively quartz-poor but clay

Background oriented schlieren in a density stratified fluid.

PubMed

Verso, Lilly; Liberzon, Alex

2015-10-01

Non-intrusive quantitative fluid density measurement methods are essential in the stratified flow experiments. Digital imaging leads to synthetic schlieren methods in which the variations of the index of refraction are reconstructed computationally. In this study, an extension to one of these methods, called background oriented schlieren, is proposed. The extension enables an accurate reconstruction of the density field in stratified liquid experiments. Typically, the experiments are performed by the light source, background pattern, and the camera positioned on the opposite sides of a transparent vessel. The multimedia imaging through air-glass-water-glass-air leads to an additional aberration that destroys the reconstruction. A two-step calibration and image remapping transform are the key components that correct the images through the stratified media and provide a non-intrusive full-field density measurements of transparent liquids.

Quality assurance of temporal variability of natural decay chain and neutron induced background for low-level NORM analysis

DOE PAGES

Yoho, Michael; Porterfield, Donivan R.; Landsberger, Sheldon

2015-09-22

In this study, twenty-one high purity germanium (HPGe) background spectra were collected over 2 years at Los Alamos National Laboratory. A quality assurance methodology was developed to monitor spectral background levels from thermal and fast neutron flux levels and naturally occurring radioactive material decay series radionuclides. 238U decay products above 222Rn demonstrated minimal temporal variability beyond that expected from counting statistics. 238U and 232Th progeny below Rn gas displayed at most twice the expected variability. Further, an analysis of the 139 keV 74Ge(n, γ) and 691 keV 72Ge(n, n') spectral features demonstrated temporal stability for both thermal and fastmore » neutron fluxes.« less

Effect of Different Levels of Pressure Relieving Air-Mattress Firmness on Cough Strength.

PubMed

Kamikawa, Norimichi; Taito, Shunsuke; Takahashi, Makoto; Sekikawa, Kiyokazu; Hamada, Hironobu

2016-01-01

Cough is an important host-defense mechanism. The elderly and patients who are severely ill cannot cough effectively when lying in the supine position. Furthermore, pressure relieving air-mattresses are recommended for preventing the development of pressure ulcers. In this study, we clarified whether or not the cough peak flow (CPF), an index of cough strength, is affected by different firmness levels of a pressure relieving air-mattress in healthy volunteers in the supine position. Fifty-two healthy young men participated. All the measurements were carried out on each participant in the supine position on a pressure relieving air-mattress. The participants were assessed at two firmness levels, a "hard" and "soft" mode. The CPF, forced vital capacity (FVC), maximal expiratory pressure (PEmax), and maximal inspiratory pressure (PImax) were determined for each mode. The sinking distance of the body into the mattress was measured without any activity and the difference between the sinking distances of the two firmness levels was determined. The CPF, FVC, PEmax, and PImax were determined for each mode. The sinking distance of the body into the mattress was measured and the difference between the sinking distances of the two firmness levels was determined. The CPF, FVC, PEmax and PImax values of the participants coughing on the mattress were significantly lower when the mattress was in "soft" than in "hard" mode. The differences between the sinking distances of the mattress in "soft" and "hard" modes were larger for the anterior superior iliac spine. A harder mattress may lead to increased CPF in healthy young men lying in the supine position, and increased CPF may be important for host defense.

Estimating representative background PM2.5 concentration in heavily polluted areas using baseline separation technique and chemical mass balance model

NASA Astrophysics Data System (ADS)

Gao, Shuang; Yang, Wen; Zhang, Hui; Sun, Yanling; Mao, Jian; Ma, Zhenxing; Cong, Zhiyuan; Zhang, Xian; Tian, Shasha; Azzi, Merched; Chen, Li; Bai, Zhipeng

2018-02-01

The determination of background concentration of PM2.5 is important to understand the contribution of local emission sources to total PM2.5 concentration. The purpose of this study was to exam the performance of baseline separation techniques to estimate PM2.5 background concentration. Five separation methods, which included recursive digital filters (Lyne-Hollick, one-parameter algorithm, and Boughton two-parameter algorithm), sliding interval and smoothed minima, were applied to one-year PM2.5 time-series data in two heavily polluted cities, Tianjin and Jinan. To obtain the proper filter parameters and recession constants for the separation techniques, we conducted regression analysis at a background site during the emission reduction period enforced by the Government for the 2014 Asia-Pacific Economic Cooperation (APEC) meeting in Beijing. Background concentrations in Tianjin and Jinan were then estimated by applying the determined filter parameters and recession constants. The chemical mass balance (CMB) model was also applied to ascertain the effectiveness of the new approach. Our results showed that the contribution of background PM concentration to ambient pollution was at a comparable level to the contribution obtained from the previous study. The best performance was achieved using the Boughton two-parameter algorithm. The background concentrations were estimated at (27 ± 2) μg/m3 for the whole year, (34 ± 4) μg/m3 for the heating period (winter), (21 ± 2) μg/m3 for the non-heating period (summer), and (25 ± 2) μg/m3 for the sandstorm period in Tianjin. The corresponding values in Jinan were (30 ± 3) μg/m3, (40 ± 4) μg/m3, (24 ± 5) μg/m3, and (26 ± 2) μg/m3, respectively. The study revealed that these baseline separation techniques are valid for estimating levels of PM2.5 air pollution, and that our proposed method has great potential for estimating the background level of other air pollutants.

Physical Activity- and Alcohol-dependent Association Between Air Pollution Exposure and Elevated Liver Enzyme Levels: An Elderly Panel Study.

PubMed

Kim, Kyoung-Nam; Lee, Hyemi; Kim, Jin Hee; Jung, Kweon; Lim, Youn-Hee; Hong, Yun-Chul

2015-05-01

The deleterious effects of air pollution on various health outcomes have been demonstrated. However, few studies have examined the effects of air pollution on liver enzyme levels. Blood samples were drawn up to three times between 2008 and 2010 from 545 elderly individuals who regularly visited a community welfare center in Seoul, Korea. Data regarding ambient air pollutants (particulate matter ≤2.5 μm [PM2.5], nitrogen dioxide [NO2], ozone [O3], carbon monoxide, and sulfur dioxide) from monitoring stations were used to estimate air pollution exposure. The effects of the air pollutants on the concentrations of three liver enzymes (aspartate aminotransferase [AST], alanine aminotransferase [ALT], and γ-glutamyltranspeptidase [γ-GTP)]) were evaluated using generalized additive and linear mixed models. Interquartile range increases in the concentrations of the pollutants showed significant associations of PM2.5 with AST (3.0% increase, p=0.0052), ALT (3.2% increase, p=0.0313), and γ-GTP (5.0% increase, p=0.0051) levels; NO2 with AST (3.5% increase, p=0.0060) and ALT (3.8% increase, p=0.0179) levels; and O3 with γ-GTP (5.3% increase, p=0.0324) levels. Significant modification of these effects by exercise and alcohol consumption was found (p for interaction <0.05). The effects of air pollutants were greater in non-exercisers and heavy drinkers. Short-term exposure to air pollutants such as PM2.5, NO2, and O3 is associated with increased liver enzyme levels in the elderly. These adverse effects can be reduced by exercising regularly and abstinence from alcohol.

Essential air service : changes in subsidy levels, air carrier costs, and passenger traffic

DOT National Transportation Integrated Search

2000-04-01

Overall, DOT applied relevant statutory authority when determining which communities would receive air service subsidized by the EAS program. Under this authority, communities may receive subsidized air service if they were initially eligible for Ess...

Molecular-level removal of proteinaceous contamination from model surfaces and biomedical device materials by air plasma treatment.

PubMed

Banerjee, K K; Kumar, S; Bremmell, K E; Griesser, H J

2010-11-01

Established methods for cleaning and sterilising biomedical devices may achieve removal of bioburden only at the macroscopic level while leaving behind molecular levels of contamination (mainly proteinaceous). This is of particular concern if the residue might contain prions. We investigated at the molecular level the removal of model and real-life proteinaceous contamination from model and practical surfaces by air plasma (ionised air) treatment. The surface-sensitive technique of X-ray photoelectron spectroscopy (XPS) was used to assess the removal of proteinaceous contamination, with the nitrogen (N1s) photoelectron signal as its marker. Model proteinaceous contamination (bovine serum albumin) adsorbed on to a model surface (silicon wafer) and the residual proteinaceous contamination resulting from incubating surgical stainless steel (a practical biomaterial) in whole human blood exhibited strong N1s signals [16.8 and 18.5 atomic percent (at.%), respectively] after thorough washing. After 5min air plasma treatment, XPS detected no nitrogen on the sample surfaces, indicating complete removal of proteinaceous contamination, down to the estimated XPS detection limit 10ng/cm(2). Applying the same plasma treatment, the 7.7at.% nitrogen observed on a clinically cleaned dental bur was reduced to a level reflective of new, as-received burs. Contact angle measurements and atomic force microscopy also indicated complete molecular-level removal of the proteinaceous contamination upon air plasma treatment. This study demonstrates the effectiveness of air plasma treatment for removing proteinaceous contamination from both model and practical surfaces and offers a method for ensuring that no molecular residual contamination such as prions is transferred upon re-use of surgical and dental instruments. Crown Copyright © 2010. Published by Elsevier Ltd. All rights reserved.

An objective classification system of air mass types for Szeged, Hungary, with special attention to plant pollen levels.

PubMed

Makra, László; Juhász, Miklós; Mika, János; Bartzokas, Aristides; Béczi, Rita; Sümeghy, Zoltán

2006-07-01

This paper discusses the characteristic air mass types over the Carpathian Basin in relation to plant pollen levels over annual pollination periods. Based on the European Centre for Medium-Range Weather Forecasts dataset, daily sea-level pressure fields analysed at 00 UTC were prepared for each air mass type (cluster) in order to relate sea-level pressure patterns to pollen levels in Szeged, Hungary. The database comprises daily values of 12 meteorological parameters and daily pollen concentrations of 24 species for their pollination periods from 1997 to 2001. Characteristic air mass types were objectively defined via factor analysis and cluster analysis. According to the results, nine air mass types (clusters) were detected for pollination periods of the year corresponding to pollen levels that appear with higher concentration when irradiance is moderate while wind speed is moderate or high. This is the case when an anticyclone prevails in the region west of the Carpathian Basin and when Hungary is under the influence of zonal currents (wind speed is high). The sea level pressure systems associated with low pollen concentrations are mostly similar to those connected to higher pollen concentrations, and arise when wind speed is low or moderate. Low pollen levels occur when an anticyclone prevails in the region west of the Carpathian Basin, as well as when an anticyclone covers the region with Hungary at its centre. Hence, anticyclonic or anticyclonic ridge weather situations seem to be relevant in classifying pollen levels.

Low Background Levels of Mars Methane at Gale Crater Indicate Seasonal Cycle: Updated Results from TLS-SAM on Curiosity

NASA Astrophysics Data System (ADS)

Webster, C. R.; Mahaffy, P. R.; Atreya, S. K.

2016-12-01

In situ measurements of atmospheric methane have been made over a 3-year period at Gale Crater on Mars using the Tunable Laser Spectrometer (TLS) instrument in the Sample Analysis at Mars (SAM) suite on the Curiosity rover. We have reported two important observations: (i) a background level of 0.5 ppbv that is about five times lower than some model predictions based on generation from UV degradation of micro-meteorites or interplanetary dust delivered to the martian surface; (ii) a "spike" of elevated levels of 7 ppbv that were seen1 on four sequential observations over a 2-month period before dropping to background levels. This spike was attributed to an episodic release from a small local source, probably to the north of Gale crater. While the elevated levels of the spike did not return (repeat) one Mars year later, we have seen what appears to be a seasonal variation to the background levels that are all < 1ppbv. The variation ranges from a low of 0.2 ppbv in the northern hemisphere spring to 0.9 ppbv in the northern hemisphere late summer, a change in mixing ratio over a range larger than expected from our current understanding of methane sources and sinks. We will present recent atmospheric methane measurements, and their correlations with a variety of environmental conditions at the location of Curiosity, and discuss the mechanisms that are believed to be contributing to the low background methane signals and their variation. 1 "Mars Methane Detection and Variability at Gale Crater", C. R. Webster et al., Science, 347, 415-417 (2015) and references therein. The research described here was carried out in part at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration (NASA).

U.S. Air Force Bomber Sustainment and Modernization: Background and Issues for Congress

DTIC Science & Technology

2013-04-23

the B-2’ s self- defense capabilities against U.S. Air Force Bomber Sustainment and Modernization: Issues for Congress...Sustaining U.S. Global Leadership: Priorities for the 21st Century Defense ; • the effectiveness and sustainability of the Air Force’s continuous...decisions considered by Congress, could have potential consequences for future national defense strategies and on U.S. long-range strike

AIR RADIOACTIVITY MONITOR

DOEpatents

Bradshaw, R.L.; Thomas, J.W.

1961-04-11

The monitor is designed to minimize undesirable background buildup. It consists of an elongated column containing peripheral electrodes in a central portion of the column, and conduits directing an axial flow of radioactively contaminated air through the center of the column and pure air through the annular portion of the column about the electrodes. (AEC)

Soil dioxins levels at agriculture sites and natural preserve areas of Taiwan.

PubMed

Jou, Jin-juh; Lin, Kae-Long; Chung, Jen-Chir; Liaw, Shu-Liang

2007-08-17

In this study, agriculture soil in Taiwan has been sampled and analyzed to determine the background level of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/DF) in the agricultural and nature preserve areas. Another objective is to investigate relationship between soil characteristics and air deposition in Taiwan. The results indicate that in nature preserve areas the topsoil shows an extraordinary profile of PCDD/DF compared to that in the air deposition. The PCDD/DF levels of the low-contaminated agricultural soils are compatible with those of the nature preserves soils. However, in the highly-contaminated agricultural soils, there is an abrupt jump in their concentrations, 10-100 times higher. The overall I-TEQ values of the background topsoils range from 0.101 to 15.2 ng I-TEQ/kg. Near industrial/urban areas in Taiwan the PCDD/DF are slightly higher compared to those in the low concentration group. Typically, the PCDD/DF background values found in this survey fall in the 90% confidence interval and can thus, be deemed the background levels in Taiwan. Ninety-five percent of these data are below the European and American soil standard of 10 ng I-TEQ/kg d.w. The PCDD/DF profile with one neighborhood soil sample was shown no significant difference.

Ozone Levels in the North and South of Jordan: Effects of Transboundary Air Pollution

NASA Astrophysics Data System (ADS)

Alsawair, Jihad Khalaf

The first phase of this work sought to assess the causes of air quality deterioration in the south of the region over the Red Sea near the resort areas of Eilat and Aqaba. Accordingly, a coordinated Jordanian-Israeli study was performed during the month of November 2007 along the boarder of the two countries. The Jordanian measurements were made at a fixed monitoring location in the city of Aqaba, while the Israeli measurements were made using a mobile laboratory at kibbutz Eilot some 3 km north of the coastal city of Eilat. The results indicated that pollution episodes are highly dependent on wind direction, where southerly winds carry local transportation (i.e., ship, trucks) and possibly some industrial emissions towards the north end of the Red Sea, while northerly winds are associated with the transport of regional O 3. The results revealed that under the prevailing (˜90% of the time) northerly wind flows, the quality of the air is relatively good for all primary pollutants but O3 was elevated, indicative of the downwind regional transport of this secondary species from the Mediterranean coast. However, during days with southerly air flow the air quality was significantly deteriorated with elevated levels of sulfur dioxide (SO2) and nitrogen oxides (NOx). The second phase of this work, which also involved Jordanian and Israeli scientists, was undertaken in the northern part of the region for a two-week period in May/June 2009. This part of the research was aimed at examining previous modeling results that indicated that elevated O3 levels should occur in Northern Jordan from emissions in Northern Israel that are transported a distance of more than 100 km. Ozone and other pollutants were monitored at five sites in Israel (Haifa, Neve Shanan, Kiryat Tivon, Afula, and Maoz Haim) and two in Jordan (Taiba and Irbid). The sites were located along the prevailing wind direction that presumably moves air-masses eastward from the Mediterranean coast, over the Israel

Assessment of Health-Cost Externalities of Air Pollution at the National Level using the EVA Model System

NASA Astrophysics Data System (ADS)

Brandt, Jørgen; Silver, Jeremy David; Heile Christensen, Jesper; Skou Andersen, Mikael; Geels, Camilla; Gross, Allan; Buus Hansen, Ayoe; Mantzius Hansen, Kaj; Brandt Hedegaard, Gitte; Ambelas Skjøth, Carsten

2010-05-01

Air pollution has significant negative impacts on human health and well-being, which entail substantial economic consequences. We have developed an integrated model system, EVA (External Valuation of Air pollution), to assess health-related economic externalities of air pollution resulting from specific emission sources/sectors. The EVA system was initially developed to assess externalities from power production, but in this study it is extended to evaluate costs at the national level. The EVA system integrates a regional-scale atmospheric chemistry transport model (DEHM), address-level population data, exposure-response functions and monetary values applicable for Danish/European conditions. Traditionally, systems that assess economic costs of health impacts from air pollution assume linear approximations in the source-receptor relationships. However, atmospheric chemistry is non-linear and therefore the uncertainty involved in the linear assumption can be large. The EVA system has been developed to take into account the non-linear processes by using a comprehensive, state-of-the-art chemical transport model when calculating how specific changes to emissions affect air pollution levels and the subsequent impacts on human health and cost. Furthermore, we present a new "tagging" method, developed to examine how specific emission sources influence air pollution levels without assuming linearity of the non-linear behaviour of atmospheric chemistry. This method is more precise than the traditional approach based on taking the difference between two concentration fields. Using the EVA system, we have estimated the total external costs from the main emission sectors in Denmark, representing the ten major SNAP codes. Finally, we assess the impacts and external costs of emissions from international ship traffic around Denmark, since there is a high volume of ship traffic in the region.

Quantile-based Bayesian maximum entropy approach for spatiotemporal modeling of ambient air quality levels.

PubMed

Yu, Hwa-Lung; Wang, Chih-Hsin

2013-02-05

Understanding the daily changes in ambient air quality concentrations is important to the assessing human exposure and environmental health. However, the fine temporal scales (e.g., hourly) involved in this assessment often lead to high variability in air quality concentrations. This is because of the complex short-term physical and chemical mechanisms among the pollutants. Consequently, high heterogeneity is usually present in not only the averaged pollution levels, but also the intraday variance levels of the daily observations of ambient concentration across space and time. This characteristic decreases the estimation performance of common techniques. This study proposes a novel quantile-based Bayesian maximum entropy (QBME) method to account for the nonstationary and nonhomogeneous characteristics of ambient air pollution dynamics. The QBME method characterizes the spatiotemporal dependence among the ambient air quality levels based on their location-specific quantiles and accounts for spatiotemporal variations using a local weighted smoothing technique. The epistemic framework of the QBME method can allow researchers to further consider the uncertainty of space-time observations. This study presents the spatiotemporal modeling of daily CO and PM10 concentrations across Taiwan from 1998 to 2009 using the QBME method. Results show that the QBME method can effectively improve estimation accuracy in terms of lower mean absolute errors and standard deviations over space and time, especially for pollutants with strong nonhomogeneous variances across space. In addition, the epistemic framework can allow researchers to assimilate the site-specific secondary information where the observations are absent because of the common preferential sampling issues of environmental data. The proposed QBME method provides a practical and powerful framework for the spatiotemporal modeling of ambient pollutants.

Next-generation air measurement technologies | Science ...

EPA Pesticide Factsheets

This is a presentation at a workshop in Chicago on emerging air monitoring technologies, hosted by a local nonprofit. The audience is composed of a mixture of technical backgrounds. This presentation will be part of an opening panel and the goal is to give an overview of the state of science on emerging air sensor technology. This is a presentation at a workshop in Chicago on emerging air monitoring technologies, hosted by a local nonprofit. The audience is composed of a mixture of technical backgrounds. This presentation will be part of an opening panel and the goal is to give an overview of the state of science on emerging air sensor technology.

Gross Alpha Beta Radioactivity in Air Filters Measured by Ultra Low Level α/β Counter

NASA Astrophysics Data System (ADS)

Cfarku, Florinda; Bylyku, Elida; Deda, Antoneta; Dhoqina, Polikron; Bakiu, Erjona; Perpunja, Flamur

2010-01-01

Study of radioactivity in air as very important for life is done regularly using different methods in every country. As a result of nuclear reactors, atomic centrals, institutions and laboratories, which use the radioactivity substances in open or closed sources, there are a lot radioactive wastes. Mixing of these wastes after treatment with rivers and lakes waters makes very important control of radioactivity. At the other side nuclear and radiological accidents are another source of the contamination of air and water. Due to their radio toxicity, especially those of Sr90, Pu239, etc. a contamination hazard for human begins exist even at low concentration levels. Measurements of radioactivity in air have been performed in many parts of the world mostly for assessment of the doses and risk resulting from consuming air. In this study we present the results of international comparison organized by IAEA Vienna, Austria for the air filters spiked with unknown Alpha and Beta Activity. For the calibration of system we used the same filters spiked: a) with Pu-239 as alpha source; b) Sr-90 as beta source and also the blank filter. The measurements of air filter samples after calibration of the system are done with Ultra Low Level α/β Counter (MPC 9604) Protean Instrument Corporation. The high sensitivity of the system for the determination of the Gross Alpha and Beta activity makes sure detection of low values activity of air filters. Our laboratory results are: Aα = (0.19±0.01) Bq/filter and Aα (IAEA) = (0.17±0.009) Bq/filter; Aβ = (0.33±0.009) Bq/filter and Aβ (IAEA) = (0.29±0.01) Bq/filter. As it seems our results are in good agreement with reference values given by IAEA (International Atomic Energy Agency).

Mercury in soil gas and air--A potential tool in mineral exploration

USGS Publications Warehouse

McCarthy, Joseph Howard; Vaughn, W.W.; Learned, R.E.; Meuschke, J.L.

1969-01-01

The mercury content in soil gas and in the atmosphere was measured in several mining districts to test the possibility that the mercury content in the atmosphere is higher over ore deposits than over barren ground. At Cortez, Nev., the distribution of anorhalous amounts of mercury in the air collected at ground level (soil gas) correlates well with the distribution of gold-bearing rocks that are covered by as much as 100 feet of gravel. The mercury content in the atmosphere collected at an altitude of 200 feet by an aircraft was 20 times background over a mercury posit and 10 times background over two porphyry copper deposits. Measurement of mercury in soil gas and air may prove to be a valuable exploration tool.

ACUTE RESPIRATORY HEALTH EFFECTS OF AIR POLLUTION ON ASTHMATIC CHILDREN IN US INNER CITIES

EPA Science Inventory

BACKGROUND: Children with asthma in inner-city communities may be particularly vulnerable to adverse effects of air pollution because of their airways disease and exposure to relatively high levels of motor vehicle emissions. OBJECTIVE: To investigate the association between fluc...

STRATEGIES TO REDUCE EXPOSURE TO TRAFFIC-RELATED AIR POLLUTION AT THE LOCAL LEVEL

EPA Science Inventory

As public health concerns for populations living, working and going to school near high-traffic roadways have increased, so have the need to identify and implement air pollution control strategies effective at the local level. While strategies implemented at the federal and stat...

Air Quality Planning Unit | Ground-level Ozone | New England ...

EPA Pesticide Factsheets

2017-09-05

Looking for answers about a specific air quality issue? Here's a list of topics and programs related to air quality and Air Quality Planning (AQP) staff who can answer questions and provide information about them.

Air Quality Planning Unit | Ground-level Ozone | New England ...

EPA Pesticide Factsheets

2017-04-10

Looking for answers about a specific air quality issue? Here's a list of topics and programs related to air quality and Air Quality Planning (AQP) staff who can answer questions and provide information about them.

Whole air canister sampling coupled with preconcentration GC/MS analysis of part-per-trillion levels of trimethylsilanol in semiconductor cleanroom air.

PubMed

Herrington, Jason S

2013-08-20

The costly damage airborne trimethylsilanol (TMS) exacts on optics in the semiconductor industry has resulted in the demand for accurate and reliable methods for measuring TMS at trace levels (i.e., parts per trillion, volume per volume of air [ppt(v)] [~ng/m(3)]). In this study I developed a whole air canister-based approach for field sampling trimethylsilanol in air, as well as a preconcentration gas chromatography/mass spectrometry laboratory method for analysis. The results demonstrate clean canister blanks (0.06 ppt(v) [0.24 ng/m(3)], which is below the detection limit), excellent linearity (a calibration relative response factor relative standard deviation [RSD] of 9.8%) over a wide dynamic mass range (1-100 ppt(v)), recovery/accuracy of 93%, a low selected ion monitoring method detection limit of 0.12 ppt(v) (0.48 ng/m(3)), replicate precision of 6.8% RSD, and stability (84% recovery) out to four days of storage at room temperature. Samples collected at two silicon wafer fabrication facilities ranged from 10.0 to 9120 ppt(v) TMS and appear to be associated with the use of hexamethyldisilazane priming agent. This method will enable semiconductor cleanroom managers to monitor and control for trace levels of trimethylsilanol.

US EPA's National Dioxin Air Monitoring Network: Analytical ...

EPA Pesticide Factsheets

The U.S. EPA has established a National Dioxin Air Monitoring Network (NDAMN) to determine the temporal and geographical variability of atmospheric chlorinated dibenzo-p-dioxins (CDDs), furans (CDFs), and coplanar polychlorinated biphenyls (PCBs) at rural and non-impacted locations throughout the United States. Currently operating at 32 sampling stations, NDAMN has three primary purposes: (1) to determine the atmospheric levels and occurrences of dioxin-like compounds in rural and agricultural areas where livestock, poultry, and animal feed crops are grown; (2) to provide measurements of atmospheric levels in different geographic regions of the U.S.; and (3) to provide information regarding the long-range transport of dioxin-like compounds in air over the U.S. Designed in 1997, NDAMN has been implemented in phases, with the first phase consisting of 9 monitoring stations and is achieving congener-specific detection lmits of 0.1 fg/m3 for 2,3,7,8-TCDD and 10 fg/m3 for OCDD. With respect to coplanar PCBs, the detection limits are generally higher due to the presence of background levels in the air during the preparation and processing of the samples. Achieving these extremely low levels of detection present a host of analytical issues. Among these issues are the methods used to establish ultra-trace detection limits, measures to ensure against and monitor for breakthrough of native analytes when sampling large volumes of air, and procedures for handling and e

Effect of Different Levels of Pressure Relieving Air-Mattress Firmness on Cough Strength

PubMed Central

Kamikawa, Norimichi; Taito, Shunsuke; Takahashi, Makoto; Sekikawa, Kiyokazu; Hamada, Hironobu

2016-01-01

Cough is an important host-defense mechanism. The elderly and patients who are severely ill cannot cough effectively when lying in the supine position. Furthermore, pressure relieving air-mattresses are recommended for preventing the development of pressure ulcers. In this study, we clarified whether or not the cough peak flow (CPF), an index of cough strength, is affected by different firmness levels of a pressure relieving air-mattress in healthy volunteers in the supine position. Fifty-two healthy young men participated. All the measurements were carried out on each participant in the supine position on a pressure relieving air-mattress. The participants were assessed at two firmness levels, a “hard” and “soft” mode. The CPF, forced vital capacity (FVC), maximal expiratory pressure (PEmax), and maximal inspiratory pressure (PImax) were determined for each mode. The sinking distance of the body into the mattress was measured without any activity and the difference between the sinking distances of the two firmness levels was determined. The CPF, FVC, PEmax, and PImax were determined for each mode. The sinking distance of the body into the mattress was measured and the difference between the sinking distances of the two firmness levels was determined. The CPF, FVC, PEmax and PImax values of the participants coughing on the mattress were significantly lower when the mattress was in “soft” than in “hard” mode. The differences between the sinking distances of the mattress in “soft” and “hard” modes were larger for the anterior superior iliac spine. A harder mattress may lead to increased CPF in healthy young men lying in the supine position, and increased CPF may be important for host defense. PMID:26741497

Time lag between the tropopause height and the levels of 7Be concentration in near surface air

NASA Astrophysics Data System (ADS)

Ioannidou, A.; Vasileiadis, A.; Melas, D.

2012-04-01

The concentration of 7Be at near surface air has been determined over 2009, a year of a deep solar minimum, in the region of Thessaloniki, Greece at 40°62' N, 22°95'E. In geomagnetic latitudes over 40° N, the elevation of the tropopause during the warm summer months and the vertical exchange of air masses within the troposphere cause greater mixture of the air masses resulting in higher concentration levels for 7Be in surface air. The positive correlation between the monthly activity concentration of 7Be and the tropopause height (0.94, p < 0.0001), and also between 7Be concentration and the temperature T (°C) (R = 0.97, p < 0.001), confirm that the increased rate of vertical transport within the troposphere, especially during warmer summer months, has as a result the descent to surface of air masses enriched in 7Be. However, the 7Be concentration levels in near surface air are not expected to respond immediately to the change of elevation of the tropopause. It was found that there's a time lag of ~ 3 days between the change in the daily surface concentrations of 7Be the change in the elevation of the tropopause.

Observations of Air Quality at the Edge of Kathmandu, Nepal, and the Diurnal Cycle of Air Pollution In and Around the Kathmandu Valley

NASA Astrophysics Data System (ADS)

Panday, A. K.; Prinn, R. G.; Regmi, R. P.

2006-12-01

The Kathmandu Valley is a bowl-shaped basin in the Nepal Himalaya, with a rapidly growing city surrounded by rice fields and steep terraced and forested mountain slopes. The valley's air quality is influenced by urban and rural emissions, nocturnal pooling of cold air, slope winds, and a daily exchange of air through mountain passes. To understand these processes and to inform air pollution policy in Nepal, we have carried out the most comprehensive study of air pollution in Nepal to date. During the 9-month dry season of 2004-2005, we carried out continuous measurements every minute of carbon monoxide, ozone, PM10, wind speed, wind direction, solar radiation, temperature, and humidity on the eastern edge of Kathmandu city, at a site that daily received air from both the city and rural areas. We recorded the diurnal cycle of the vertical temperature structure and stability with temperature loggers on towers and mountains. A sodar measured the mixed layer height and upper-level winds. 24-hour simultaneous bag sampling campaigns on mountain peaks, passes, the rural valley, and within the city provided glimpses of the spatial patterns of the diurnal cycle of CO -- a useful tracer of anthropogenic emissions. We measured winds on mountain passes and ozone on mountain peaks. At our main measurement site we found a daily-recurring pattern of CO and PM10, with an afternoon low showing rural background levels, even though the arriving air had traversed the city. This was followed by an evening peak starting at sunset, a second low late at night, and a morning peak enhanced by re-circulation. Pollutants emitted in the valley only traveled out of the valley between the late morning and sunset. During winter months, rush hour was outside of this period, enhancing the morning and evening peaks. Within the city, ozone dropped to zero at night. At mid-day we observed an ozone peak enhanced by photochemical production when the air mass that had been stagnant over the city swept

Transcriptome analysis reveals a stress response of Shewanella oneidensis deprived of background levels of ionizing radiation

PubMed Central

Li, Xiaoping; Schilkey, Faye; Smith, Geoffrey B.

2018-01-01

Natural ionizing background radiation has exerted a constant pressure on organisms since the first forms of life appeared on Earth, so that cells have developed molecular mechanisms to avoid or repair damages caused directly by radiation or indirectly by radiation-induced reactive oxygen species (ROS). In the present study, we investigated the transcriptional effect of depriving Shewanella oneidensis cultures of background levels of radiation by growing the cells in a mine 655 m underground, thus reducing the dose rate from 72.1 to 0.9 nGy h-1 from control to treatment, respectively. RNASeq transcriptome analysis showed the differential expression of 4.6 and 7.6% of the S. oneidensis genome during early- and late-exponential phases of growth, respectively. The greatest change observed in the treatment was the downregulation of ribosomal proteins (21% of all annotated ribosomal protein genes during early- and 14% during late-exponential) and tRNA genes (14% of all annotated tRNA genes in early-exponential), indicating a marked decrease in protein translation. Other significant changes were the upregulation of membrane transporters, implying an increase in the traffic of substrates across the cell membrane, as well as the up and downregulation of genes related to respiration, which could be interpreted as a response to insufficient oxidants in the cells. In other reports, there is evidence in multiple species that some ROS not just lead to oxidative stress, but act as signaling molecules to control cellular metabolism at the transcriptional level. Consistent with these reports, several genes involved in the metabolism of carbon and biosynthesis of amino acids were also regulated, lending support to the idea of a wide metabolic response. Our results indicate that S. oneidensis is sensitive to the withdrawal of background levels of ionizing radiation and suggest that a transcriptional response is required to maintain homeostasis and retain normal growth. PMID:29768440

3. AERIAL VIEW FROM THE EAST OF (FOREGROUND TO BACKGROUND) ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

3. AERIAL VIEW FROM THE EAST OF (FOREGROUND TO BACKGROUND) SLC-3 AIR FORCE BUILDING (BLDG. 761), TECHNICAL SUPPORT BUILDING (BLDG. 762/762A), ENTRY CONTROL POINT (BLDG. 768), AND LOB (BLDG. 763). EAST SIDE OF SLC-3E MOBILE SERVICE TOWER (MST) VISIBLE IN UPPER LEFT CORNER. - Vandenberg Air Force Base, Space Launch Complex 3, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

STEMS-Air: a simple GIS-based air pollution dispersion model for city-wide exposure assessment.

PubMed

Gulliver, John; Briggs, David

2011-05-15

Current methods of air pollution modelling do not readily meet the needs of air pollution mapping for short-term (i.e. daily) exposure studies. The main limiting factor is that for those few models that couple with a GIS there are insufficient tools for directly mapping air pollution both at high spatial resolution and over large areas (e.g. city wide). A simple GIS-based air pollution model (STEMS-Air) has been developed for PM(10) to meet these needs with the option to choose different exposure averaging periods (e.g. daily and annual). STEMS-Air uses the grid-based FOCALSUM function in ArcGIS in conjunction with a fine grid of emission sources and basic information on meteorology to implement a simple Gaussian plume model of air pollution dispersion. STEMS-Air was developed and validated in London, UK, using data on concentrations of PM(10) from routinely available monitoring data. Results from the validation study show that STEMS-Air performs well in predicting both daily (at four sites) and annual (at 30 sites) concentrations of PM(10). For daily modelling, STEMS-Air achieved r(2) values in the range 0.19-0.43 (p<0.001) based solely on traffic-related emissions and r(2) values in the range 0.41-0.63 (p<0.001) when adding information on 'background' levels of PM(10). For annual modelling of PM(10), the model returned r(2) in the range 0.67-0.77 (P<0.001) when compared with monitored concentrations. The model can thus be used for rapid production of daily or annual city-wide air pollution maps either as a screening process in urban air quality planning and management, or as the basis for health risk assessment and epidemiological studies. Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved.

Impact of air quality guidelines on COPD sufferers

PubMed Central

Liu, Youcheng; Yan, Shuang; Poh, Karen; Liu, Suyang; Iyioriobhe, Emanehi; Sterling, David A

2016-01-01

Background COPD is one of the leading causes of morbidity and mortality in both high- and low-income countries and a major public health burden worldwide. While cigarette smoking remains the main cause of COPD, outdoor and indoor air pollution are important risk factors to its etiology. Although studies over the last 30 years helped reduce the values, it is not very clear if the current air quality guidelines are adequately protective for COPD sufferers. Objective This systematic review was to summarize the up-to-date literature on the impact of air pollution on the COPD sufferers. Methods PubMed and Google Scholar were utilized to search for articles related to our study’s focus. Search terms included “COPD exacerbation”, “air pollution”, “air quality guidelines”, “air quality standards”, “COPD morbidity and mortality”, “chronic bronchitis”, and “air pollution control” separately and in combination. We focused on articles from 1990 to 2015. We also used articles prior to 1990 if they contained relevant information. We focused on articles written in English or with an English abstract. We also used the articles in the reference lists of the identified articles. Results Both short-term and long-term exposures to outdoor air pollution around the world are associated with the mortality and morbidity of COPD sufferers even at levels below the current air quality guidelines. Biomass cooking in low-income countries was clearly associated with COPD morbidity in adult nonsmoking females. Conclusion There is a need to continue to improve the air quality guidelines. A range of intervention measures could be selected at different levels based on countries’ socioeconomic conditions to reduce the air pollution exposure and COPD burden. PMID:27143874

Traffic Impacts on PM2.5 Air Quality in Nairobi, Kenya

PubMed Central

Kinney, Patrick L.; Gichuru, Michael Gatari; Volavka-Close, Nicole; Ngo, Nicole; Ndiba, Peter K.; Law, Anna; Gachanja, Anthony; Gaita, Samuel Mwaniki; Chillrud, Steven N.; Sclar, Elliott

2011-01-01

Motor vehicle traffic is an important source of particulate pollution in cities of the developing world, where rapid growth, coupled with a lack of effective transport and land use planning, may result in harmful levels of fine particles (PM2.5) in the air. However, a lack of air monitoring data hinders health impact assessments and the development of transportation and land use policies that could reduce health burdens due to outdoor air pollution. To address this important need, a study of traffic-related PM2.5 was carried out in the city of Nairobi, Kenya, a model city for sub-Saharan Africa, in July 2009. Sampling was carried out using portable filter-based air samplers carried in backpacks by technicians on weekdays over two weeks at several sites in and around Nairobi ranging from high-traffic roadways to rural background. Mean daytime concentrations of PM2.5 ranged from 10.7 at the rural background site to 98.1 μg/m3 on a sidewalk in the central business district. Horizontal dispersion measurements demonstrated a decrease in PM2.5 concentration from 128.7 to 18.7 μg/m3 over 100 meters downwind of a major intersection in Nairobi. A vertical dispersion experiment revealed a decrease from 119.5 μg/m3 at street level to 42.8 μg/m3 on a third-floor rooftop in the central business district. Though not directly comparable to air quality guidelines, which are based on 24-hour or annual averages, the urban concentrations we observed raise concern with regard to public health and related policy. Taken together with survey data on commuting patterns within Nairobi, these results suggest that many Nairobi residents are exposed on a regular basis to elevated concentrations of fine particle air pollution, with potentially serious long-term implications for health. PMID:21779151

Assimilation of Atmospheric InfraRed Sounder (AIRS) Profiles using WRF-Var

NASA Technical Reports Server (NTRS)

Zavodsky, Brad; Jedlovec, Gary J.; Lapenta, William

2008-01-01

The Weather Research and Forecasting (WRF) model contains a three-dimensional variational (3DVAR) assimilation system (WRF-Var), which allows a user to join data from multiple sources into one coherent analysis. WRF-Var combines observations with a background field traditionally generated using a previous model forecast through minimization of a cost function. In data sparse regions, remotely-sensed observations may be able to improve analyses and produce improved forecasts. One such source comes from the Atmospheric Infrared Sounder (AIRS), which together with the Advanced Microwave Sounding Unit (AMSU), represents one of the most advanced space-based atmospheric sounding systems. The combined AIRS/AMSU system provides radiance measurements used as input to a sophisticated retrieval scheme which has been shown to produce temperature profiles with an accuracy of 1 K over 1 km layers and humidity profiles with accuracy of 15% in 2 km layers in both clear and partly cloudy conditions. The retrieval algorithm also provides estimates of the accuracy of the retrieved values at each pressure level, allowing the user to select profiles based on the required error tolerances of the application. The purpose of this paper is to describe a procedure to optimally assimilate high-resolution AIRS profile data into a regional configuration of the Advanced Research WRF (ARW) version 2.2 using WRF-Var. The paper focuses on development of background error covariances for the regional domain and background field type using gen_be and an optimal methodology for ingesting AIRS temperature and moisture profiles as separate overland and overwater retrievals with different error characteristics in the WRF-Var. The AIRS thermodynamic profiles are obtained from the version 5.0 Earth Observing System (EOS) science team retrieval algorithm and contain information about the quality of each temperature layer. The quality indicators are used to select the highest quality temperature and moisture

Characteristics of atmospheric carbon monoxide at a high-mountain background station in East Asia

NASA Astrophysics Data System (ADS)

Ou-Yang, Chang-Feng; Lin, Neng-Huei; Lin, Chia-Ching; Wang, Sheng-Hsiang; Sheu, Guey-Rong; Lee, Chung-Te; Schnell, Russell C.; Lang, Patricia M.; Kawasato, Taro; Wang, Jia-Lin

2014-06-01

Atmospheric CO were monitored at the Lulin Atmospheric Background Station (LABS) with an elevation of 2862 m AMSL from April 2006 to April 2011 by the in-situ non-dispersive infrared (NDIR) spectrometer and weekly flask sample collections via collaboration with NOAA/ESRL/GMD. In general very coherent results were observed between the two datasets, despite a slight difference between the two. A distinct seasonal pattern of CO was noticed at the LABS with a springtime maximum and a summertime minimum, which was predominately shaped by the long-range transport of biomass burning air masses from Southeast Asia and oceanic influences from the Pacific, respectively. Diurnal cycles were also observed at the LABS, with a maximum in late afternoon and a minimum in early morning. The daytime CO maximum was most likely caused by the up-slope transport of lower elevation air. After filtering out the possibly polluted data points from the entire dataset with a mathematic procedure, the mean background CO level at the LABS was assessed as 129.3 ± 46.6 ppb, compared to 149.0 ± 72.2 ppb prior to the filtering. The cluster analysis of the backward trajectories revealed six possible source regions, which shows that air masses originating from the Westerly Wind Zone were dominated in spring and winter resulting in higher CO concentrations. As a contrast, the oceanic influences from the Pacific were found mostly in summer, contributing a lower seasonal CO concentration throughout a year.

In the Background

ERIC Educational Resources Information Center

Garibay, Pat

2007-01-01

Educators and administrators are looking for new ways to boost student performance and eliminate barriers to learning. When working to improve the classroom environment, facility managers typically target the physical structure, temperature controls, humidity levels and ventilation. Many heating, ventilating and air conditioning (HVAC) consultants…

Background Acoustics Levels in the 9x15 Wind Tunnel and Linear Array Testing

NASA Technical Reports Server (NTRS)

Stephens, David

2011-01-01

The background noise level in the 9x15 foot wind tunnel at NASA Glenn has been documented, and the results compare favorably with historical measurements. A study of recessed microphone mounting techniques was also conducted, and a recessed cavity with a micronic wire mesh screen reduces hydrodynamic noise by around 10 dB. A three-microphone signal processing technique can provide additional benefit, rejecting up to 15 dB of noise contamination at some frequencies. The screen and cavity system offers considerable benefit to test efficiency, although there are additional calibration requirements.

GSOD Based Daily Global Mean Surface Temperature and Mean Sea Level Air Pressure (1982-2011)

DOE Data Explorer

Xuan Shi, Dali Wang

2014-05-05

This data product contains all the gridded data set at 1/4 degree resolution in ASCII format. Both mean temperature and mean sea level air pressure data are available. It also contains the GSOD data (1982-2011) from NOAA site, contains station number, location, temperature and pressures (sea level and station level). The data package also contains information related to the data processing methods

From Good Intentions to Proven Interventions: Effectiveness of Actions to Reduce the Health Impacts of Air Pollution

PubMed Central

Giles, Luisa V.; Barn, Prabjit; Künzli, Nino; Romieu, Isabelle; Mittleman, Murray A.; van Eeden, Stephan; Allen, Ryan; Carlsten, Chris; Stieb, Dave; Noonan, Curtis; Smargiassi, Audrey; Kaufman, Joel D.; Hajat, Shakoor; Kosatsky, Tom; Brauer, Michael

2011-01-01

Background Associations between air pollution and a multitude of health effects are now well established. Given ubiquitous exposure to some level of air pollution, the attributable health burden can be high, particularly for susceptible populations. Objectives An international multidisciplinary workshop was convened to discuss evidence of the effectiveness of actions to reduce health impacts of air pollution at both the community and individual level. The overall aim was to summarize current knowledge regarding air pollution exposure and health impacts leading to public health recommendations. Discussion During the workshop, experts reviewed the biological mechanisms of action of air pollution in the initiation and progression of disease, as well as the state of the science regarding community and individual-level interventions. The workshop highlighted strategies to reduce individual baseline risk of conditions associated with increased susceptibility to the effects of air pollution and the need to better understand the role of exposure duration in disease progression, reversal, and adaptation. Conclusion We have identified two promising and largely unexplored strategies to address and mitigate air pollution–related health impacts: reducing individual baseline risk of cardiovascular disease and incorporating air pollution–related health impacts into land-use decisions. PMID:20729178

Understanding the rapid growth of background concentrations of methane in 2007

NASA Astrophysics Data System (ADS)

Witham, C. S.; Manning, A. J.; O'Doherty, S.; Simmonds, P. G.

2009-04-01

The growth of background levels of atmospheric methane showed a marked increase in both hemispheres in 2007. This paper looks at the data from a range of observation stations that monitor methane at high frequency, including Barrow (Alaska), Ragged Point (Barbados), Trinidad Head (California), Cape Grim (Australia), Cape Matatula (Samoa), Gosan (South Korea) and Mace Head (Ireland), to try to understand the likely causes for this sudden rise. At each station the recent history of the air arriving at each station is considered using the NAME model. NAME (Numerical Atmospheric-dispersion Modelling Environment) is a Lagrangian atmospheric dispersion model that uses 3D meteorology from the UK Met Office numerical weather prediction model. High temporal resolution and high precision measurements of a wide range of trace gases in ambient air are available from the instrumentation at the AGAGE (Advanced Global Atmospheric Gases Experiment), NOAA and Korean measurement stations. The locations of these stations span both hemispheres and therefore allow global changes to be monitored. In this work, we are primarily interested in the measurements of methane and carbon monoxide. Baseline concentrations of methane and carbon monoxide have been determined for both the Northern and Southern Hemispheres using NAME and statistical post-processing of the observations at each measurement station. For this application, NAME is run backwards in time for ten days for each 3-hour interval for the years of specific interest 2006-2008 inclusive, releasing thousands of model particles at each observing site. A map is then produced estimating all of the surface (0-100m) contributions within ten days of travel arriving at each site during each interval. The resulting matrix describes the dilution in concentration that occurs from a unit release from each grid as it travels to the measurement site. By identifying regions where air is expected to be unpolluted, baseline periods can be

TISSUE CONCENTRATION OF PCBS IN ANIMAL EXPERIMENTS AS COMPARED WITH THOSE IN HUMANS WITH BACKGROUND-LEVEL EXPOSURE

EPA Science Inventory

TISSUE CONCENTRATION OF PCBS IN ANIMAL EXPERIMENTS AS COMPARED WITH THOSE IN HUMANS WITH BACKGROUND-LEVEL EXPOSURE. M J DeVito1 and M P Longnecker2. 1NHEERL, ORD, USEPA; Research Triangle Park, NC, USA; 2Epidemiology
Branch, NIEHS, Research Triangle Park, NC, USA.

To ...

Generalized water-level contours, September-October 2000 and March-April 2001, and long-term water-level changes, at the U.S. Air Force Plant 42 and vicinity, Palmdale, California

USGS Publications Warehouse

Christensen, Allen H.

2005-01-01

Historically, the U.S. Air Force Plant 42 has relied on ground water as the primary source of water owing, in large part, to the scarcity of surface water in the region. Groundwater withdrawal for municipal, industrial, and agricultural use has affected ground-water levels at U.S. Air Force Plant 42, and vicinity. A study to document changes in groundwater gradients and to present historical water-level data was completed by the U.S. Geological Survey in cooperation with the U.S. Air Force. This report presents historical water-level data, hydrographs, and generalized seasonal water-level and water-level contours for September?October 2000 and March?April 2001. The collection and interpretation of ground-water data helps local water districts, military bases, and private citizens gain a better understanding of the ground-water flow systems, and consequently water availability. During September?October 2000 and March?April 2001 the U.S. Geological Survey and other agencies made a total of 102 water-level measurements, 46 during September?October 2000 and 56 during March?April 2001. These data document recent conditions and, when compared with historical data, document changes in ground-water levels. Two water-level contour maps were drawn: the first depicts water-level conditions for September?October 2000 map and the second depicts water-level conditions for March?April 2001 map. In general, the water-level contour maps show water-level depressions formed as result of ground-water withdrawal. One hundred sixteen long-term hydrographs, using water-level data from 1915 through 2000, were constructed to show water-level trends in the area. The hydrographs indicate that water-level decline occurred throughout the study area, with the greatest declines south of U.S. Air Force Plant 42.

Limitations of STIRAP-like population transfer in extended systems: the three-level system embedded in a web of background states.

PubMed

Jakubetz, Werner

2012-12-14

This paper presents a systematic numerical investigation of background state participation in STIRAP (stimulated Raman-adiabatic passage) population transfer among vibrational states, focusing on the consequences for the robustness of the method. The simulations, which are performed over extended grids in the parameter space of the Stokes- and pump pulses (frequencies, field strengths, and pulse lengths), involve hierarchies of (3 + N)-level systems of increasing complexity, ranging from the standard three-level STIRAP setup, (N = 0) in Λ-configuration, up to N = 446. A strongly coupled three-level core system is selected from the full Hamiltonian of the double-well HCN∕HNC system, and the couplings connecting this core system to the remaining states are (re-) parameterized in different ways, from very weak to very strong. The systems so obtained represent a three-level system embedded in various ways in webs of cross-linked vibrational background states and incorporate typical molecular properties. We first summarize essential properties of population transfer in the standard three-level system and quantify the robustness of the method and its dependence on the pulse parameters. Against these reference results, we present results obtained for four (3 + 446)-level systems and several subsystems. For pulse lengths of at most few picoseconds the intrinsic robustness of STIRAP with respect to variations in the field strength disappears as soon as the largest core-background couplings exceed about one tenth of the STIRAP couplings. In such cases robustness with respect to variations in the field strength is entirely lost, since at higher field strengths, except for irregularly spaced narrow frequency ranges, transfer probabilities are strongly reduced. STIRAP-like population transfer is maintained, with some restrictions, at low field strengths near the onset of adiabatic transfer. The suppression of STIRAP is traced back to different mechanisms based on a

Exposures to Walkability and Particulate Air Pollution in a Nationwide Cohort of Women

PubMed Central

James, Peter; Hart, Jaime E.; Laden, Francine

2015-01-01

Background Features of neighborhoods associated with walkability (i.e., connectivity, accessibility, and density) may also be correlated with levels of ambient air pollution, which would attenuate the health benefits of walkability. Objectives We examined the relationship between neighborhood walkability and ambient air pollution in a cross-sectional analysis of a cohort study spanning the entire United States using residence-level exposure assessment for ambient air pollution and the built environment. Methods Using data from the Nurses’ Health Study, we used linear regression to estimate the association between a neighborhood walkability index, combining neighborhood intersection count, business count, and population density (defined from Census data, infoUSA business data, and StreetMap USA data), and air pollution, defined from a GIS-based spatiotemporal PM2.5 model. Results After adjustment for Census tract median income, median home value, and percent with no high school education, the highest tertile of walkability index, intersection count, business count, and population density was associated with a with 1.58 (95% CI 1.54, 1.62), 1.20 (95% CI 1.16, 1.24), 1.31 (95% CI 1.27, 1.35), and 1.84 (95% CI 1.80, 1.88) μg/m3 higher level of PM2.5 respectively, compared to the lowest tertile. Results varied somewhat by neighborhood socioeconomic status and greatly by region. Conclusions This nationwide analysis showed a positive relationship between neighborhood walkability and modeled air pollution levels, which were consistent after adjustment for neighborhood-level socioeconomic status. Regional differences in the air pollution-walkability relationship demonstrate that there are factors that vary across region that allow for walkable neighborhoods with low levels of air pollution. PMID:26397775

Comparing and evaluating model estimates of background ozone in surface air over North America

NASA Astrophysics Data System (ADS)

Oberman, J.; Fiore, A. M.; Lin, M.; Zhang, L.; Jacob, D. J.; Naik, V.; Horowitz, L. W.

2011-12-01

Tropospheric ozone adversely affects human health and vegetation, and is thus a criteria pollutant regulated by the U.S. Environmental Protection Agency (EPA) under the National Ambient Air Quality Standard (NAAQS). Ozone is produced in the atmosphere via photo-oxidation of volatile organic compounds (VOCs) and carbon monoxide (CO) in the presence of nitrogen oxides (NOx). The present EPA approach considers health risks associated with exposure to ozone enhancement above the policy-relevant background (PRB), which is currently defined as the surface concentration of ozone that would exist without North American anthropogenic emissions. PRB thus includes production by natural precursors, production by precursors emitted on foreign continents, and transport of stratospheric ozone into surface air. As PRB is not an observable quantity, it must be estimated using numerical models. We compare PRB estimates for the year 2006 from the GFDL Atmospheric Model 3 (AM3) chemistry-climate model (CCM) and the GEOS-Chem (GC) chemical transport model (CTM). We evaluate the skill of the models in reproducing total surface ozone observed at the U.S. Clean Air Status and Trends Network (CASTNet), dividing the stations into low-elevation (< 1.5 km in altitude, primarily eastern) and high-elevation (> 1.5 km in altitude, all western) subgroups. At the low-elevation sites AM3 estimates of PRB (38±9 ppbv in spring, 27±9 ppbv in summer) are higher than GC (27±7 ppbv in spring, 21±8 ppbv in summer) in both seasons. Analysis at these sites is complicated by a positive bias in AM3 total ozone with respect to the observed total ozone, the source of which is yet unclear. At high-elevation sites, AM3 PRB is higher in the spring (47±8 ppbv) than in the summer (33±8 ppbv). In contrast, GC simulates little seasonal variation at high elevation sites (39±5 ppbv in spring vs. 38±7 ppbv in summer). Seasonal average total ozone at these sites was within 4 ppbv of the observations for both

Trend in Air Quality of Kathmandu Valley: A Satellite, Observation and Modelling Perspective

NASA Astrophysics Data System (ADS)

Mahapatra, P. S.; Praveen, P. S.; Adhikary, B.; Panday, A. K.; Putero, D.; Bonasoni, P.

2016-12-01

Kathmandu (floor area of 340 km2) in Nepal is considered to be a `hot spot' of urban air pollution in South Asia. Its structure as a flat basin surrounded by tall mountains provides a unique case study for analyzing pollution trapped by topography. Only a very small number of cities with similar features have been studied extensively including Mexico and Santiago-de-Chile. This study presents the trend in satellite derived Aerosol Optical Depth (AOD) from MODIS AQUA and TERRA (3x3km, Level 2) over Kathmandu from 2000 to 2015. Trend analysis of AOD shows 35% increase during the study period. Determination of the background pollution would reveal the contribution of only Kathmandu Valley for the observation period. For this, AOD at 1340m altitude outside Kathmandu, but nearby areas were considered as background. This analysis was further supported by investigating AOD at different heights around Kathmandu as well as determining AOD from CALIPSO vertical profiles. These analysis suggest that background AOD contributed 30% in winter and 60% in summer to Kathmandu Valley's observed AOD. Thereafter the background AOD was subtracted from total Kathmandu AOD to determine contribution of only Kathmandu Valley's AOD. Trend analysis of only Kathmandu Valley AOD (subtracting background AOD) suggested an increase of 50% during the study period. Further analysis of Kathmandu's visibility and AOD suggest profound role of background AOD on decreasing visibility. In-situ Black Carbon (BC) mass concentration measurements (BC being used as a proxy for surface observations) at two sites within Kathmandu valley have been analyzed. Kathmandu valley lacks long term trends of ambient air quality measurement data. Therefore, surface observations would be coupled with satellite measurements for understanding the urban air pollution scenario. Modelling studies to estimate the contribution of background pollution to Kathmandu's own pollution as well as the weekend effect on air quality will

Social Background, Composition and Educational Growth.

ERIC Educational Resources Information Center

Mare, Robert D.

1979-01-01

Studies the impact of changes in family background on grade-level attainment for White males between 1907-1951. Findings show that the effects of social background on grade attainment decrease with increasing levels of attainment. Reprint available from Institute for Research on Poverty, University of Wisconsin-Madison, Madison WI 53706. (AM)

Artificial neural networks as a useful tool to predict the risk level of Betula pollen in the air

NASA Astrophysics Data System (ADS)

Castellano-Méndez, M.; Aira, M. J.; Iglesias, I.; Jato, V.; González-Manteiga, W.

2005-05-01

An increasing percentage of the European population suffers from allergies to pollen. The study of the evolution of air pollen concentration supplies prior knowledge of the levels of pollen in the air, which can be useful for the prevention and treatment of allergic symptoms, and the management of medical resources. The symptoms of Betula pollinosis can be associated with certain levels of pollen in the air. The aim of this study was to predict the risk of the concentration of pollen exceeding a given level, using previous pollen and meteorological information, by applying neural network techniques. Neural networks are a widespread statistical tool useful for the study of problems associated with complex or poorly understood phenomena. The binary response variable associated with each level requires a careful selection of the neural network and the error function associated with the learning algorithm used during the training phase. The performance of the neural network with the validation set showed that the risk of the pollen level exceeding a certain threshold can be successfully forecasted using artificial neural networks. This prediction tool may be implemented to create an automatic system that forecasts the risk of suffering allergic symptoms.

Measurement of volatile plant compounds in field ambient air by thermal desorption-gas chromatography-mass spectrometry.

PubMed

Cai, Xiao-Ming; Xu, Xiu-Xiu; Bian, Lei; Luo, Zong-Xiu; Chen, Zong-Mao

2015-12-01

Determination of volatile plant compounds in field ambient air is important to understand chemical communication between plants and insects and will aid the development of semiochemicals from plants for pest control. In this study, a thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS) method was developed to measure ultra-trace levels of volatile plant compounds in field ambient air. The desorption parameters of TD, including sorbent tube material, tube desorption temperature, desorption time, and cold trap temperature, were selected and optimized. In GC-MS analysis, the selected ion monitoring mode was used for enhanced sensitivity and selectivity. This method was sufficiently sensitive to detect part-per-trillion levels of volatile plant compounds in field ambient air. Laboratory and field evaluation revealed that the method presented high precision and accuracy. Field studies indicated that the background odor of tea plantations contained some common volatile plant compounds, such as (Z)-3-hexenol, methyl salicylate, and (E)-ocimene, at concentrations ranging from 1 to 3400 ng m(-3). In addition, the background odor in summer was more abundant in quality and quantity than in autumn. Relative to previous methods, the TD-GC-MS method is more sensitive, permitting accurate qualitative and quantitative measurements of volatile plant compounds in field ambient air.

Seasonal ambient air pollution correlates strongly with spontaneous abortion in Mongolia

PubMed Central

2014-01-01

Background Air pollution is a major health challenge worldwide and has previously been strongly associated with adverse reproductive health. This study aimed to examine the association between spontaneous abortion and seasonal variation of air pollutants in Ulaanbaatar, Mongolia. Methods Monthly average O3, SO2, NO2, CO, PM10 and PM2.5 levels were measured at Mongolian Government Air Quality Monitoring stations. The medical records of 1219 women admitted to the hospital due to spontaneous abortion between 2009–2011 were examined retrospectively. Fetal deaths per calendar month from January-December, 2011 were counted and correlated with mean monthly levels of various air pollutants by means of regression analysis. Results Regression of ambient pollutants against fetal death as a dose–response toxicity curve revealed very strong dose–response correlations for SO2 r > 0.9 (p < 0.001) while similarly strongly significant correlation coefficients were found for NO2 (r > 0.8), CO (r > 0.9), PM10 (r > 0.9) and PM2.5 (r > 0.8), (p < 0.001), indicating a strong correlation between air pollution and decreased fetal wellbeing. Conclusion The present study identified alarmingly strong statistical correlations between ambient air pollutants and spontaneous abortion. Further studies need to be done to examine possible correlations between personal exposure to air pollutants and pregnancy loss. PMID:24758249

Effects of Environmental Air Pollution on Pulmonary Function Level of Residents in Korean Industrial Complexes.

PubMed

Hong, Eunju; Lee, Seokwon; Kim, Geun-Bae; Kim, Tae-Jong; Kim, Hyoung-Wook; Lee, Kyoungho; Son, Bu-Soon

2018-04-24

This study aims to identify environmental air pollution adversely affecting pulmonary function among a community-based general population living in Korean industrial complexes. A total of 1963 residents participated in a pulmonary function test (PFT). The sample population consisted of an exposed group ( n = 1487) living within a radius of 5 km of industrial complexes and a control group ( n = 476) living over a radius of 10 km from the industrial complexes in Gwangyang and Yeosu cities. PFT results were calculated for each resident of the study population. On-site questionnaire surveys with face-to-face interviews were also conducted to collect more detailed information on personal lifestyles, medical history, exposure to air pollution, and respiratory disease and related symptoms. A total of 486 measured samples were collected by eight automated air-monitoring stations installed in four counties of Gwangyang and four counties of Yeosu in South Korea from January 2006 to February 2007. Mean levels of SO₂ (0.012 ppm), CO (0.648 ppm), NO₂ (0.02 ppm), O₃ (0.034 ppm), and PM 10 (43.07 μg/m³), collected within a radius of 5 km, were significantly higher than those collected over a radius of 10 km from Gwangyang and Yeosu industrial complexes. Prevalence odds ratio (OR) of abnormal pulmonary function in the exposed group of residents (<5 km) was elevated at 1.24 (95% CI 0.71⁻1.96), but not statistically significant ( p > 0.05). In multiple linear regression analysis, forced expiratory volume in one second (FEV₁) and forced vital capacity (FVC) levels significantly declined as SO₂, CO, and O₃ levels increased when adjusting for age, sex, body mass index (BMI), alcohol, smoking, secondhand smoke, and respiratory disease and related symptoms ( n = 1963) ( p < 0.05). These results suggest that exposure to air pollution affects pulmonary function levels of residents living in Korean industrial complexes.

Traffic-related air pollution and lung cancer: A meta-analysis

PubMed Central

Chen, Gongbo; Wan, Xia; Yang, Gonghuan; Zou, Xiaonong

2015-01-01

Background We conducted a meta-analysis to evaluate the association between traffic-related air pollution and lung cancer in order to provide evidence for control of traffic-related air pollution. Methods Several databases were searched for relevant studies up to December 2013. The quality of articles obtained was evaluated by the Strengthening the Reporting of Observational Studies in Epidemiology checklist. Statistical analysis, including pooling effective sizes and confidential intervals, was performed. Results A total of 1106 records were obtained through the database and 36 studies were included in our analysis. Among the studies included, 14 evaluated the association between ambient exposure to traffic-related air pollution and lung cancer and 22 studies involved occupational exposure to air pollution among professional drivers. Twenty-two studies were marked A level regarding quality, 13 were B level, and one was C level. Exposure to nitrogen dioxide (meta-odds ratio [OR]: 1.06, 95% confidence interval [CI]: 0.99–1.13), nitrogen oxide (meta-OR: 1.04, 95% CI: 1.01–1.07), sulfur dioxide (meta-OR: 1.03, 95% CI: 1.02–1.05), and fine particulate matter (meta-OR: 1.11, 95% CI: 1.00–1.22) were positively associated with a risk of lung cancer. Occupational exposure to air pollution among professional drivers significantly increased the incidence (meta-OR: 1.27, 95% CI: 1.19–1.36) and mortality of lung cancer (meta-OR: 1.14, 95% CI: 1.04–1.26). Conclusion Exposure to traffic-related air pollution significantly increased the risk of lung cancer. PMID:26273377

Air Force KC-X Tanker Aircraft Program: Background and Issues for Congress

DTIC Science & Technology

2010-03-12

obtained by CRS. 16 Gopal Ratnam and Alison Fitzgerald , “Northrop Declines Tanker Bid on...1-50. 19 Statement of General Duncan J. McNabb, USAF, Commander, United States Transportation Command, Before the House Armed Services Air & Land

Passive inhalation of marijuana smoke: urinalysis and room air levels of delta-9-tetrahydrocannabinol

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

Cone, E.J.; Johnson, R.E.; Darwin, W.D.

In two separate studies, 5 drug-free male volunteers with a history of marijuana use were passively exposed to the sidestream smoke of 4 and 16 marijuana cigarettes (2.8% delta-9-tetrahydrocannabinol (THC)) for 1 h each day for 6 consecutive days. A third study was similarly performed with 2 marijuana-naive subjects passively exposed to the smoke of 16 marijuana cigarettes. Passive smoke exposure was conducted in a small, unventilated room. Room air levels of THC and CO were monitored frequently. All urine specimens were collected and analyzed by EMIT d.a.u. assay, Abuscreen radioimmunoassay and GC/MS. The studies show that significant amounts ofmore » THC were absorbed by all subjects at the higher level of passive smoke exposure (eg., smoke from 16 marijuana cigarettes), resulting in urinary excretion of significant amounts of cannabinoid metabolites. However, it seems improbable that subjects would unknowingly tolerate the noxious smoke conditions produced by this exposure. At the lower level of passive marijuana-smoke exposure, specimens tested positive only infrequently or were negative. Room air levels of THC during passive smoke exposure appeared to be the most critical factor in determining whether a subject produced cannabinoid-positive urine specimens.« less

Exploring EKC, trends of growth patterns and air pollutants concentration level in Malaysia: A Nemerow Index Approach

NASA Astrophysics Data System (ADS)

Bekhet, Hussain A.; >Tahira Yasmin,

2013-06-01

The present study examines an Environmental Kuznets Curve (EKC) hypothesis by analyzing annual data of air pollutants concentartion and per capita GDP as economic indicator over the (1996-2010) period in Malaysia. Nemerow Index Approach (I) used to generate a measures of air pollution. The results show that ambient air quality indicators supports the EKC hypothesis which stated that pollution levels increase as a country develops, but begin to decrease as rising incomes pass beyond a turning poin. Also, the I result is justifying that most pollutants are showing value less than 1.

Judgments of aircraft noise in a traffic noise background

NASA Technical Reports Server (NTRS)

Powell, C. A.; Rice, C. G.

1975-01-01

An investigation was conducted to determine subjective response to aircraft noise in different road traffic backgrounds. In addition, two laboratory techniques for presenting the aircraft noise with the background noise were evaluated. For one technique, the background noise was continuous over an entire test session; for the other, the background noise level was changed with each aircraft noise during a session. Subjective response to aircraft noise was found to decrease with increasing background noise level, for a range of typical indoor noise levels. Subjective response was found to be highly correlated with the Noise Pollution Level (NPL) measurement scale.

An integrated bi-level optimization model for air quality management of Beijing's energy system under uncertainty.

PubMed

Jin, S W; Li, Y P; Nie, S

2018-05-15

In this study, an interval chance-constrained bi-level programming (ICBP) method is developed for air quality management of municipal energy system under uncertainty. ICBP can deal with uncertainties presented as interval values and probability distributions as well as examine the risk of violating constraints. Besides, a leader-follower decision strategy is incorporated into the optimization process where two decision makers with different goals and preferences are involved. To solve the proposed model, a bi-level interactive algorithm based on satisfactory degree is introduced into the decision-making processes. Then, an ICBP based energy and environmental systems (ICBP-EES) model is formulated for Beijing, in which air quality index (AQI) is used for evaluating the integrated air quality of multiple pollutants. Result analysis can help different stakeholders adjust their tolerances to achieve the overall satisfaction of EES planning for the study city. Results reveal that natural gas is the main source for electricity-generation and heating that could lead to a potentially increment of imported energy for Beijing in future. Results also disclose that PM 10 is the major contributor to AQI. These findings can help decision makers to identify desired alternatives for EES planning and provide useful information for regional air quality management under uncertainty. Copyright © 2018 Elsevier B.V. All rights reserved.

Burden of Outdoor Air Pollution in Kerala, India—A First Health Risk Assessment at State Level.

PubMed

Tobollik, Myriam; Razum, Oliver; Wintermeyer, Dirk; Plass, Dietrich

2015-08-28

Ambient air pollution causes a considerable disease burden, particularly in South Asia. The objective of the study is to test the feasibility of applying the environmental burden of disease method at state level in India and to quantify a first set of disease burden estimates due to ambient air pollution in Kerala. Particulate Matter (PM) was used as an indicator for ambient air pollution. The disease burden was quantified in Years of Life Lost (YLL) for the population (30 + years) living in urban areas of Kerala. Scenario analyses were performed to account for uncertainties in the input parameters. 6108 (confidence interval (95% CI): 4150-7791) of 81,636 total natural deaths can be attributed to PM, resulting in 96,359 (95% CI: 65,479-122,917) YLLs due to premature mortality (base case scenario, average for 2008-2011). Depending on the underlying assumptions the results vary between 69,582 and 377,195 YLLs. Around half of the total burden is related to cardiovascular deaths. Scenario analyses show that a decrease of 10% in PM concentrations would save 15,904 (95% CI: 11,090-19,806) life years. The results can be used to raise awareness about air quality standards at a local level and to support decision-making processes aiming at cleaner and healthier environments.

Quantifying the Impact of Background Atmospheric Stability on Air-Ice-Ocean Interactions the Arctic Ocean During the Fall Freeze-Up

NASA Astrophysics Data System (ADS)

Guest, P. S.; Persson, O. P. G.; Blomquist, B.; Fairall, C. W.

2016-02-01

"Background" stability refers to the effect of vertical virtual temperature variations above the surface layer on fluxes within the surface layer. This is different from the classical surface layer stability quantified by the Obhukhov length scale. In most locations, changes in the background stability do not have a significant direct impact on surface fluxes. However in polar regions, where there is usually a strong low-level temperature inversion capping the boundary layer, changes in background stability can have big impacts on surface fluxes. Therefore, in the Arctic, there is potential for a positive feedback effect between ice cover and surface wind speed (and momentum flux) due to the background stability effects. As the surface becomes more ice free, heat fluxes from the surface weaken the temperature inversion which in turn increases the surface wind speed which further increases the surface turbulent heat fluxes and removes more sea ice by melting or advection. It is not clear how important feedbacks involving the background stability are during the fall freeze up of the Arctic Ocean; that will be the focus of this study. As part of an ONR-sponsored cruise in the fall of 2015 to examine sea state and boundary layer processes in the Beaufort Sea on the R/V Sikuliaq, the authors will perform a variety of surface layer and upper level atmospheric measurements of temperature, humidity and wind vector using ship platform instruments, radiosonde weather balloons, tethered balloons, kites, and miniature quad-rotor unmanned aerial vehicles. In addition, the authors will deploy a full suite of turbulent and radiational flux measurements from the vessel. These measurements will be used to quantify the impact of changing surface conditions on atmospheric structure and vice-versa. The goal is to directly observe how the surface and atmosphere above the surface layer interact and feedback with each other through radiational and turbulent fluxes.

Notification: Background Investigation Services New Assignment Notification: EPA’s Efforts to Incorporate Environmental Justice Into Clean Air Act Inspections for Air Toxics

EPA Pesticide Factsheets

The purpose of this memorandum is to notify you that the EPA OIG plans to begin the preliminary research phase of an evaluation of the U.S. EPA's efforts to incorporate environmental justice into Clean Air Act inspections for air toxics.

Air Contamination by Mercury, Emissions and Transformations-a Review.

PubMed

Gworek, Barbara; Dmuchowski, Wojciech; Baczewska, Aneta H; Brągoszewska, Paulina; Bemowska-Kałabun, Olga; Wrzosek-Jakubowska, Justyna

2017-01-01

The present and future air contamination by mercury is and will continue to be a serious risk for human health. This publication presents a review of the literature dealing with the issues related to air contamination by mercury and its transformations as well as its natural and anthropogenic emissions. The assessment of mercury emissions into the air poses serious methodological problems. It is particularly difficult to distinguish between natural and anthropogenic emissions and re-emissions from lands and oceans, including past emissions. At present, the largest emission sources include fuel combustion, mainly that of coal, and "artisanal and small-scale gold mining" (ASGM). The distinctly highest emissions can be found in South and South-East Asia, accounting for 45% of the global emissions. The emissions of natural origin and re-emissions are estimated at 45-66% of the global emissions, with the largest part of emissions originating in the oceans. Forecasts on the future emission levels are not unambiguous; however, most forecasts do not provide for reductions in emissions. Ninety-five percent of mercury occurring in the air is Hg 0 -GEM, and its residence time in the air is estimated at 6 to 18 months. The residence times of its Hg II -GOM and that in Hg p -TPM are estimated at hours and days. The highest mercury concentrations in the air can be found in the areas of mercury mines and those of ASGM. Since 1980 when it reached its maximum, the global background mercury concentration in the air has remained at a relatively constant level.

Background Underground at WIPP

NASA Astrophysics Data System (ADS)

Esch, Ernst-Ingo; Hime, A.; Bowles, T. J.

2001-04-01

Recent interest to establish a dedicated underground laboratory in the United States prompted an experimental program at to quantify the enviromental backgrounds underground at the Waste Isolation Pilot Plant (WIPP) in Carlsbad, New Mexico. An outline of this program is provided along with recent experimental data on the cosmic ray muon flux at the 650 meter level of WIPP. The implications of the cosmic ray muon and fast neutron background at WIPP will be discussed in the context of new generation, low background experiments envisioned in the future.

On the spatial distribution and evolution of ultrafine aerosols in urban air

NASA Astrophysics Data System (ADS)

Dall'Osto, M.; Querol, X.; Alastuey, A.; O'Dowd, C.; Harrison, R. M.; Wenger, J.; Gómez-Moreno, F. J.

2012-07-01

Sources and evolution of ultrafine particles (<0.1 μ m diameter) were investigated both horizontally and vertically in the large urban agglomerate of Barcelona, Spain. Within the SAPUSS project (Solving Aerosol Problems by Using Synergistic Strategies), a large number of instruments was deployed simultaneously at different monitoring sites (road, two urban background, regional background, urban tower 150 μa.s.l., urban background tower site 80 m a.s.l.) during a 4 week period in September-October 2010. Particle number concentrations (N>5nm) are highly correlated with black carbon (BC) at all sites only under strong vehicular traffic influences. By contrast, under clean atmospheric conditions (low condensation sinks, CS) such correlation diverges towards much higher N/BC ratios at all sites, indicating additional sources of particles including secondary production of freshly nucleated particles. This is also evident in the urban background annual mean diurnal trend of N/BC, showing a midday peak in all seasons. Size-resolved aerosol distributions (N10-500) as well as particle number concentrations (N>5nm) allow us to identify two types of nucleation and growth events: a regional type event originating in the whole study region and impacting almost simultaneously the urban city of Barcelona and the surrounding background area; and an urban type which originates only within the city centre but whose growth continues while transported away from the city to the regional background. Furthermore, during these clean air days, higher N are found at tower level than at ground level only in the city centre whereas such a difference is not so pronounced at the remote urban background tower. In other words, this study suggests that the column of air above the city ground level possesses the best compromise between low CS and high vapour source, hence enhancing the concentrations of freshly nucleated particles. By contrast, within stagnant polluted atmospheric conditions

42 CFR 84.1139 - Air velocity and noise levels; hoods and helmets; minimum requirements.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 42 Public Health 1 2011-10-01 2011-10-01 false Air velocity and noise levels; hoods and helmets; minimum requirements. 84.1139 Section 84.1139 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF...

42 CFR 84.1139 - Air velocity and noise levels; hoods and helmets; minimum requirements.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 42 Public Health 1 2013-10-01 2013-10-01 false Air velocity and noise levels; hoods and helmets; minimum requirements. 84.1139 Section 84.1139 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF...

42 CFR 84.1139 - Air velocity and noise levels; hoods and helmets; minimum requirements.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 42 Public Health 1 2014-10-01 2014-10-01 false Air velocity and noise levels; hoods and helmets; minimum requirements. 84.1139 Section 84.1139 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF...

42 CFR 84.1139 - Air velocity and noise levels; hoods and helmets; minimum requirements.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 42 Public Health 1 2012-10-01 2012-10-01 false Air velocity and noise levels; hoods and helmets; minimum requirements. 84.1139 Section 84.1139 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF...

42 CFR 84.1139 - Air velocity and noise levels; hoods and helmets; minimum requirements.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 42 Public Health 1 2010-10-01 2010-10-01 false Air velocity and noise levels; hoods and helmets; minimum requirements. 84.1139 Section 84.1139 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF...

Microbial contamination level of air in animal waste utilization plants.

PubMed

Chmielowiec-Korzeniowska, Anna; Tymczyna, Leszek; Drabik, Agata; Krzosek, Łukasz

2016-01-01

The aim of this research was evaluation of microbial contamination of air within and in the vicinity of animal waste disposal plants. Air samples were analyzed to determine total bacterial and fungal counts as well as microbial species composition. Measurements of climate conditions (temperature, humidity, air motion) and total dust concentration were also performed. Total numbers of bacteria and fungi surpassed the threshold limit values for production halls. The most abundant bacteria detected were those consisting of physiological microflora of animal dermis and mucosa. Fungal species composition proved to be most differentiated in the air beyond the plant area. Aspergillus versicolor, a pathogenic and allergenic filamentous fungus, was isolated only inside the rendering plant processing hall. The measurement results showed a low sanitary-hygienic state of air in the plant processing halls and substantial air pollution in its immediate vicinity.

Background noise in piezoresistive, electret condenser, and ceramic microphones.

PubMed

Zuckerwar, Allan J; Kuhn, Theodore R; Serbyn, Roman M

2003-06-01

Background noise studies have been extended from air condenser microphones to piezoresistive, electret condenser, and ceramic microphones. Theoretical models of the respective noise sources within each microphone are developed and are used to derive analytical expressions for the noise power spectral density for each type. Several additional noise sources for the piezoresistive and electret microphones, beyond what had previously been considered, were applied to the models and were found to contribute significantly to the total noise power spectral density. Experimental background noise measurements were taken using an upgraded acoustic isolation vessel and data acquisition system, and the results were compared to the theoretically obtained expressions. The models were found to yield power spectral densities consistent with the experimental results. The measurements reveal that the 1/f noise coefficient is strongly correlated with the diaphragm damping resistance, irrespective of the detection technology, i.e., air condenser, piezoresistive, etc. This conclusion has profound implications upon the expected 1/f noise component of micromachined (MEMS) microphones.

Long-term dynamics of death rates of emphysema, asthma, and pneumonia and improving air quality

PubMed Central

Kravchenko, Julia; Akushevich, Igor; Abernethy, Amy P; Holman, Sheila; Ross, William G; Lyerly, H Kim

2014-01-01

Background The respiratory tract is a major target of exposure to air pollutants, and respiratory diseases are associated with both short- and long-term exposures. We hypothesized that improved air quality in North Carolina was associated with reduced rates of death from respiratory diseases in local populations. Materials and methods We analyzed the trends of emphysema, asthma, and pneumonia mortality and changes of the levels of ozone, sulfur dioxide (SO2), nitrogen dioxide (NO2), carbon monoxide (CO), and particulate matters (PM2.5 and PM10) using monthly data measurements from air-monitoring stations in North Carolina in 1993–2010. The log-linear model was used to evaluate associations between air-pollutant levels and age-adjusted death rates (per 100,000 of population) calculated for 5-year age-groups and for standard 2000 North Carolina population. The studied associations were adjusted by age group-specific smoking prevalence and seasonal fluctuations of disease-specific respiratory deaths. Results Decline in emphysema deaths was associated with decreasing levels of SO2 and CO in the air, decline in asthma deaths–with lower SO2, CO, and PM10 levels, and decline in pneumonia deaths–with lower levels of SO2. Sensitivity analyses were performed to study potential effects of the change from International Classification of Diseases (ICD)-9 to ICD-10 codes, the effects of air pollutants on mortality during summer and winter, the impact of approach when only the underlying causes of deaths were used, and when mortality and air-quality data were analyzed on the county level. In each case, the results of sensitivity analyses demonstrated stability. The importance of analysis of pneumonia as an underlying cause of death was also highlighted. Conclusion Significant associations were observed between decreasing death rates of emphysema, asthma, and pneumonia and decreases in levels of ambient air pollutants in North Carolina. PMID:25018627

Peak Sound Pressure Levels and Associated Auditory Risk from an H[subscript 2]-Air "Egg-Splosion"

ERIC Educational Resources Information Center

Dolhun, John J.

2016-01-01

The noise level from exploding chemical demonstrations and the effect they could have on audiences, especially young children, needs attention. Auditory risk from H[subscript 2]- O2 balloon explosions have been studied, but no studies have been done on H[subscript 2]-air "eggsplosions." The peak sound pressure level (SPL) was measured…

On the validity of the incremental approach to estimate the impact of cities on air quality

NASA Astrophysics Data System (ADS)

Thunis, Philippe

2018-01-01

The question of how much cities are the sources of their own air pollution is not only theoretical as it is critical to the design of effective strategies for urban air quality planning. In this work, we assess the validity of the commonly used incremental approach to estimate the likely impact of cities on their air pollution. With the incremental approach, the city impact (i.e. the concentration change generated by the city emissions) is estimated as the concentration difference between a rural background and an urban background location, also known as the urban increment. We show that the city impact is in reality made up of the urban increment and two additional components and consequently two assumptions need to be fulfilled for the urban increment to be representative of the urban impact. The first assumption is that the rural background location is not influenced by emissions from within the city whereas the second requires that background concentration levels, obtained with zero city emissions, are equal at both locations. Because the urban impact is not measurable, the SHERPA modelling approach, based on a full air quality modelling system, is used in this work to assess the validity of these assumptions for some European cities. Results indicate that for PM2.5, these two assumptions are far from being fulfilled for many large or medium city sizes. For this type of cities, urban increments are largely underestimating city impacts. Although results are in better agreement for NO2, similar issues are met. In many situations the incremental approach is therefore not an adequate estimate of the urban impact on air pollution. This poses issues in terms of interpretation when these increments are used to define strategic options in terms of air quality planning. We finally illustrate the interest of comparing modelled and measured increments to improve our confidence in the model results.

Groundwater level and nitrate concentration trends on Mountain Home Air Force Base, southwestern Idaho

USGS Publications Warehouse

Williams, Marshall L.

2014-01-01

Mountain Home Air Force Base in southwestern Idaho draws most of its drinking water from the regional aquifer. The base is located within the State of Idaho's Mountain Home Groundwater Management Area and is adjacent to the State's Cinder Cone Butte Critical Groundwater Area. Both areas were established by the Idaho Department of Water Resources in the early 1980s because of declining water levels in the regional aquifer. The base also is listed by the Idaho Department of Environmental Quality as a nitrate priority area. The U.S. Geological Survey, in cooperation with the U.S. Air Force, began monitoring wells on the base in 1985, and currently monitors 25 wells for water levels and 17 wells for water quality, primarily nutrients. This report provides a summary of water-level and nitrate concentration data collected primarily between 2001 and 2013 and examines trends in those data. A Regional Kendall Test was run to combine results from all wells to determine an overall regional trend in water level. Groundwater levels declined at an average rate of about 1.08 feet per year. Nitrate concentration trends show that 3 wells (18 percent) are increasing in nitrate concentration trend, 3 wells (18 percent) show a decreasing nitrate concentration trend, and 11 wells (64 percent) show no nitrate concentration trend. Six wells (35 percent) currently exceed the U.S. Environmental Protection Agency's maximum contaminant limit of 10 milligrams per liter for nitrate (nitrite plus nitrate, measured as nitrogen).

A Causal Inference Analysis of the Effect of Wildland Fire Smoke on Ambient Air Pollution Levels and Health Burden

EPA Science Inventory

Wildfire smoke is a major contributor to ambient air pollution levels. In this talk, we develop a spatio-temporal model to estimate the contribution of fire smoke to overall air pollution in different regions of the country. We combine numerical model output with observational da...

Improving Regional Forecast by Assimilating Atmospheric InfraRed Sounder (AIRS) Profiles into WRF Model

NASA Technical Reports Server (NTRS)

Chou, Shih-Hung; Zavodsky, Brad; Jedlovec, Gary J.

2009-01-01

In data sparse regions, remotely-sensed observations can be used to improve analyses and produce improved forecasts. One such source comes from the Atmospheric InfraRed Sounder (AIRS), which together with the Advanced Microwave Sounding Unit (AMSU), represents one of the most advanced space-based atmospheric sounding systems. The purpose of this paper is to describe a procedure to optimally assimilate high resolution AIRS profile data into a regional configuration of the Advanced Research WRF (ARW) version 2.2 using WRF-Var. The paper focuses on development of background error covariances for the regional domain and background type, and an optimal methodology for ingesting AIRS temperature and moisture profiles as separate overland and overwater retrievals with different error characteristics. The AIRS thermodynamic profiles are derived from the version 5.0 Earth Observing System (EOS) science team retrieval algorithm and contain information about the quality of each temperature layer. The quality indicators were used to select the highest quality temperature and moisture data for each profile location and pressure level. The analyses were then used to conduct a month-long series of regional forecasts over the continental U.S. The long-term impacts of AIRS profiles on forecast were assessed against verifying NAM analyses and stage IV precipitation data.

The thickness design of unintentionally doped GaN interlayer matched with background doping level for InGaN-based laser diodes

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

Chen, P.; Zhao, D. G., E-mail: dgzhao@red.semi.ac.cn; Jiang, D. S.

2016-03-15

In order to reduce the internal optical loss of InGaN laser diodes, an unintentionally doped GaN (u-GaN) interlayer is inserted between InGaN/GaN multiple quantum well active region and Al{sub 0.2}Ga{sub 0.8}N electron blocking layer. The thickness design of u-GaN interlayer matching up with background doping level for improving laser performance is studied. It is found that a suitably chosen u-GaN interlayer can well modulate the optical absorption loss and optical confinement factor. However, if the value of background doping concentration of u-GaN interlayer is too large, the output light power may decrease. The analysis of energy band diagram of amore » LD structure with 100 nm u-GaN interlayer shows that the width of n-side depletion region decreases when the background concentration increases, and may become even too small to cover whole MQW, resulting in a serious decrease of the output light power. It means that a suitable interlayer thickness design matching with the background doping level of u-GaN interlayer is significant for InGaN-based laser diodes.« less

Comparison of indoor air quality management strategies between the school and district levels in New York State.

PubMed

Lin, Shao; Kielb, Christine L; Reddy, Amanda L; Chapman, Bonnie R; Hwang, Syni-An

2012-03-01

Good school indoor air quality (IAQ) can affect the health and functioning of school occupants. Thus, it is important to assess the degree to which schools and districts employ strategies to ensure good IAQ management. We examined and compared the patterns of IAQ management strategies between public elementary schools and their school districts in New York State. District-level information obtained from surveys of district facilities managers in 326 districts was described and stratified by district size and socioeconomic status. School-level information obtained from surveys of head custodians in 770 elementary schools was then compared with the district-level information in 241 districts. About 47% of participating school districts reported having a district-wide IAQ program, with a large range in the prevalence of specific IAQ management strategies. Airing out newly painted areas was the most commonly reported (92%) and having a classroom animal policy was the least commonly reported (29%). Larger districts and districts with a district-wide IAQ program were more likely to report certain IAQ strategies than other districts. Elementary schools and their districts were most likely to report airing out newly painted areas (76%). The most common area of disagreement was construction after hours (50%). The top strategy not reported at either level was having an IAQ coordinator (53%). Many school districts lack key IAQ management strategies, and differences exist between district-level policy and school-level practice. Districts and schools should work together to formalize and expand existing IAQ policies and inform stakeholders about these strategies. © 2012, American School Health Association.

Air Force F-22 Fighter Program: Background and Issues for Congress

DTIC Science & Technology

2009-11-25

recover those critical skills becomes increasingly expensive, particularly where F-22 comprises a large share of their overall business.23 The Air...15, is offering for sale on the international market an upgraded version of the F-15 called the Silent Eagle, which incorporates some added stealth...is only stealthy from the front,” Hirata says, referencing a limitation shared by the Eurofighter Typhoon. “I am afraid that the F-15 Silent Eagle

Burden of Outdoor Air Pollution in Kerala, India—A First Health Risk Assessment at State Level

PubMed Central

Tobollik, Myriam; Razum, Oliver; Wintermeyer, Dirk; Plass, Dietrich

2015-01-01

Ambient air pollution causes a considerable disease burden, particularly in South Asia. The objective of the study is to test the feasibility of applying the environmental burden of disease method at state level in India and to quantify a first set of disease burden estimates due to ambient air pollution in Kerala. Particulate Matter (PM) was used as an indicator for ambient air pollution. The disease burden was quantified in Years of Life Lost (YLL) for the population (30 + years) living in urban areas of Kerala. Scenario analyses were performed to account for uncertainties in the input parameters. 6108 (confidence interval (95% CI): 4150–7791) of 81,636 total natural deaths can be attributed to PM, resulting in 96,359 (95% CI: 65,479–122,917) YLLs due to premature mortality (base case scenario, average for 2008–2011). Depending on the underlying assumptions the results vary between 69,582 and 377,195 YLLs. Around half of the total burden is related to cardiovascular deaths. Scenario analyses show that a decrease of 10% in PM concentrations would save 15,904 (95% CI: 11,090–19,806) life years. The results can be used to raise awareness about air quality standards at a local level and to support decision-making processes aiming at cleaner and healthier environments. PMID:26343701

Ultra-Low Background Measurements Of Decayed Aerosol Filters

NASA Astrophysics Data System (ADS)

Miley, H.

2009-04-01

To experimentally evaluate the opportunity to apply ultra-low background measurement methods to samples collected, for instance, by the Comprehensive Test Ban Treaty International Monitoring System (IMS), aerosol samples collected on filter media were measured using HPGe spectrometers of varying low-background technology approaches. In this way, realistic estimates of the impact of low-background methodology can be assessed on the Minimum Detectable Activities obtained in systems such as the IMS. The current measurement requirement of stations in the IMS is 30 microBq per cubic meter of air for 140Ba, or about 106 fissions per daily sample. Importantly, this is for a fresh aerosol filter. Decay varying form 3 days to one week reduce the intrinsic background from radon daughters in the sample. Computational estimates of the improvement factor for these decayed filters for underground-based HPGe in clean shielding materials are orders of magnitude less, even when the decay of the isotopes of interest is included.

Indoor air pollution levels in public buildings in Thailand and exposure assessment.

PubMed

Klinmalee, Aungsiri; Srimongkol, Kasama; Kim Oanh, Nguyen Thi

2009-09-01

Levels of pollutants including PM2.5 and PM2.5 composition (black carbon and water soluble ions), SO(2), NO(2), CO, CO(2), and BTEX (benzene, toluene, ethylbenzene, xylene) were monitored for indoor and outdoor air at a university campus and a shopping center, both located in the Northern suburb of Bangkok. Sampling was done during December 2005-February 2006 on both weekdays and weekends. At the university, indoor monitoring was done in two different air conditioned classrooms which shows the I/O ratios for all pollutants to be below 0.5-0.8 during the weekends. However, on weekdays the ratios for CO(2) and most detected BTEX were above 1.0. The concept of classroom occupancy was defined using a function of the student number in a lecture hour and the number of lecture hours per day. Classroom 2, which had a higher occupancy than classroom 1, was characterized by higher concentrations of most pollutants. PM2.5 was an exception and was higher in classroom 1 (37 microg/m(3), weekdays) as compared to classroom 2 (26 microg/m(3), weekdays) which was likely linked to the dust resuspension from the carpeted floor in the former. Monitoring was also done in the shopping mall at three different sites. Indoor pollutants levels and the I/O ratios at the shopping mall were higher than at the university. Levels of all pollutants measured at the car park, except for toluene and CO(2), were the highest. I/O ratios of the pollutants at the mall were above 1.0, which indicates the relatively higher influence of the indoor sources. However, the black carbon content in PM2.5 outdoor is higher than indoor, which suggest the important contribution from outdoor combustion sources such as the traffic. Major sources of outdoor air pollution in the areas were briefly discussed. Exposure modeling was applied using the time activity and measured pollutant concentrations to assess the exposure of different groups of people in the study areas. High exposure to PM2.5, especially for the people

Nitrogen Chemistry in Sea Level Air Following Large Radiation Doses.

DTIC Science & Technology

1984-06-15

majur reactions NO + 0 + M +N0 2 + M (9) ’.o, NO+0 3 +N 2 +0 2 (1) NO + HO2 + NO2 + OH (11) 0 + NO2 NO + U 2 (12) H + NO2 + No + OOH (13) NO + OH...8217 ’, ,-7- 0 DEPARTMENT OF THE NAVY DEPARTMENT OF THE AIR FORCE (Continued) 0 Joint Cruise Missiles Project...Ofc Air Force Space Technology Ctr ATTN: JCMG-707 ATTN: YH Naval Air Systems Command Air Force !-!ight Aeronautical Lab/AAAD ATTN: PMA 271 ATjN: W

Investigation of levels in ambient air near sources of Polychlorinated Biphenyls (PCBs) in Kanpur, India, and risk assessment due to inhalation.

PubMed

Goel, Anubha; Upadhyay, Kritika; Chakraborty, Mrinmoy

2016-05-01

Polychlorinated biphenyls (PCBs) are a class of organic compounds listed as persistent organic pollutant and have been banned for use under Stockholm Convention (1972). They were used primarily in transformers and capacitors, paint, flame retardants, plasticizers, and lubricants. PCBs can be emitted through the primary and secondary sources into the atmosphere, undergo long-range atmospheric transport, and hence have been detected worldwide. Reported levels in ambient air are generally higher in urban areas. Active sampling of ambient air was conducted in Kanpur, a densely populated and industrialized city in the Indo-Gangetic Plain, for detection of 32 priority PCBs, with the aim to determine the concentration in gas/particle phase and assess exposure risk. More than 50 % of PCBs were detected in air. Occurrence in particles was dominated by heavier congeners, and levels in gas phase were below detection. Levels determined in this study are lower than the levels in Coastal areas of India but are at par with other Asian countries where majority of sites chosen for sampling were urban industrial areas. Human health risk estimates through air inhalation pathway were made in terms of lifetime average daily dose (LADD) and incremental lifetime cancer risks (ILCR). The study found lower concentrations of PCBs than guideline values and low health risk estimates through inhalation within acceptable levels, indicating a minimum risk to the adults due to exposure to PCBs present in ambient air in Kanpur.

Background Mole Fractions of Hydrocarbons in North America Determined from NOAA Global Reference Network Data

NASA Astrophysics Data System (ADS)

Mielke-Maday, I.

2015-12-01

The National Oceanic and Atmospheric Administration (NOAA) Global Monitoring Division (GMD) maintains a global reference network for over 50 trace gas species and analyzes discrete air samples collected by this network throughout the world at the Earth System Research Laboratory in Boulder, Colorado. In particular, flask samples are analyzed for a number of hydrocarbons with policy and health relevance such as ozone precursors, greenhouse gases, and hazardous air pollutants. Because this global network's sites are remote and therefore minimally influenced by local anthropogenic emissions, these data yield information about background ambient mole fractions and can provide a context for observations collected in intensive field campaigns, such as the Front Range Air Pollution and Photochemistry Experiment (FRAPPE), the Southeast Nexus (SENEX) study, and the DISCOVER-AQ deployments. Information about background mole fractions during field campaigns is critical for calculating hydrocarbon enhancements in the region of study and for assessing the extent to which a particular region's local emissions sources contribute to these enhancements. Understanding the geographic variability of the background and its contribution to regional ambient mole fractions is also crucial for the development of realistic regulations. We present background hydrocarbon mole fractions and their ratios in North America using data from air samples collected in the planetary boundary layer at tall towers and aboard aircraft from 2008 to 2014. We discuss the spatial and seasonal variability in these data. We present trends over the time period of measurements and propose possible explanations for these trends.

Changes of plasma vWF level in response to the improvement of air quality: an observation of 114 healthy young adults.

PubMed

Yuan, Zhonghai; Chen, Yan; Zhang, Ying; Liu, Hui; Liu, Qian; Zhao, Jun; Hu, Min; Huang, Wei; Wang, Guangfa; Zhu, Tong; Zhang, Jim; Zhu, Ping

2013-04-01

Plasma von Willebrand factor (vWF) is an important factor involving in hemostasis and various cardiovascular diseases. Air pollution is related to many respiratory and cardiovascular diseases. During the Olympic Games Beijing 2008 period (August 8 to September 17, 2008) when air quality in Beijing improved greatly, we studied the relationship between plasma vWF level and the factors of air pollution index (API), ABO blood group, and polymorphisms in vWF gene in healthy young adults. We recruited 114 healthy medical students. In a period of more than 4 months around the period of Olympic Games Beijing 2008, six blood samples at stages 1 and 2 (before Olympic Games), stages 3 and 4 (during Olympic Games), and stages 5 and 6 (after Olympic Games) were taken from every participant for the measurement of plasma vWF level and genotyping of three SNPs (rs7954855, rs7965413, and rs216311) in vWF gene. Daily air pollution index near their living places was obtained from the officially published data. The average API began to decrease from stage 2, reached to nadir in stages 3 and 4, and increased but was still lower in stages 5 and 6. Plasma vWF decreased during the experimental period in all participants. The average plasma vWF decreased from stage 2 and remained lower in stages 3-6. vWF level varied greatly among the participants (from 30 to 170 %) but decreased proportionately when we analyzed their levels individually. Participants with O blood type had lower plasma vWF level than those with A, B, and AB blood types. Those with the SNP in vWF gene causing homozygous threonine at codon 1381 had lower plasma vWF level than those with homozygous alanine or heterozygous alanine/threonine. In the 114 normal individuals, the average plasma vWF level decreased during the period of Olympic Games Beijing 2008 when air quality improved greatly. This suggests that control of air pollution may be useful to prevent some diseases such as cardiovascular diseases.

Sophisticated Clean Air Strategies Required to Mitigate Against Particulate Organic Pollution

PubMed Central

Grigas, T.; Ovadnevaite, J.; Ceburnis, D.; Moran, E.; McGovern, F. M.; Jennings, S. G.; O’Dowd, C.

2017-01-01

Since the 1980’s, measures mitigating the impact of transboundary air pollution have been implemented successfully as evidenced in the 1980–2014 record of atmospheric sulphur pollution over the NE-Atlantic, a key region for monitoring background northern-hemisphere pollution levels. The record reveals a 72–79% reduction in annual-average airborne sulphur pollution (SO4 and SO2, respectively) over the 35-year period. The NE-Atlantic, as observed from the Mace Head research station on the Irish coast, can be considered clean for 64% of the time during which sulphate dominates PM1 levels, contributing 42% of the mass, and for the remainder of the time, under polluted conditions, a carbonaceous (organic matter and Black Carbon) aerosol prevails, contributing 60% to 90% of the PM1 mass and exhibiting a trend whereby its contribution increases with increasing pollution levels. The carbonaceous aerosol is known to be diverse in source and nature and requires sophisticated air pollution policies underpinned by sophisticated characterisation and source apportionment capabilities to inform selective emissions-reduction strategies. Inauspiciously, however, this carbonaceous concoction is not measured in regulatory Air Quality networks. PMID:28303958

Sophisticated Clean Air Strategies Required to Mitigate Against Particulate Organic Pollution

NASA Astrophysics Data System (ADS)

Grigas, T.; Ovadnevaite, J.; Ceburnis, D.; Moran, E.; McGovern, F. M.; Jennings, S. G.; O'Dowd, C.

2017-03-01

Since the 1980’s, measures mitigating the impact of transboundary air pollution have been implemented successfully as evidenced in the 1980-2014 record of atmospheric sulphur pollution over the NE-Atlantic, a key region for monitoring background northern-hemisphere pollution levels. The record reveals a 72-79% reduction in annual-average airborne sulphur pollution (SO4 and SO2, respectively) over the 35-year period. The NE-Atlantic, as observed from the Mace Head research station on the Irish coast, can be considered clean for 64% of the time during which sulphate dominates PM1 levels, contributing 42% of the mass, and for the remainder of the time, under polluted conditions, a carbonaceous (organic matter and Black Carbon) aerosol prevails, contributing 60% to 90% of the PM1 mass and exhibiting a trend whereby its contribution increases with increasing pollution levels. The carbonaceous aerosol is known to be diverse in source and nature and requires sophisticated air pollution policies underpinned by sophisticated characterisation and source apportionment capabilities to inform selective emissions-reduction strategies. Inauspiciously, however, this carbonaceous concoction is not measured in regulatory Air Quality networks.

Sophisticated Clean Air Strategies Required to Mitigate Against Particulate Organic Pollution.

PubMed

Grigas, T; Ovadnevaite, J; Ceburnis, D; Moran, E; McGovern, F M; Jennings, S G; O'Dowd, C

2017-03-17

Since the 1980's, measures mitigating the impact of transboundary air pollution have been implemented successfully as evidenced in the 1980-2014 record of atmospheric sulphur pollution over the NE-Atlantic, a key region for monitoring background northern-hemisphere pollution levels. The record reveals a 72-79% reduction in annual-average airborne sulphur pollution (SO 4 and SO 2 , respectively) over the 35-year period. The NE-Atlantic, as observed from the Mace Head research station on the Irish coast, can be considered clean for 64% of the time during which sulphate dominates PM 1 levels, contributing 42% of the mass, and for the remainder of the time, under polluted conditions, a carbonaceous (organic matter and Black Carbon) aerosol prevails, contributing 60% to 90% of the PM 1 mass and exhibiting a trend whereby its contribution increases with increasing pollution levels. The carbonaceous aerosol is known to be diverse in source and nature and requires sophisticated air pollution policies underpinned by sophisticated characterisation and source apportionment capabilities to inform selective emissions-reduction strategies. Inauspiciously, however, this carbonaceous concoction is not measured in regulatory Air Quality networks.

Compressed air noise reductions from using advanced air gun nozzles in research and development environments.

PubMed

Prieve, Kurt; Rice, Amanda; Raynor, Peter C

2017-08-01

The aims of this study were to evaluate sound levels produced by compressed air guns in research and development (R&D) environments, replace conventional air gun models with advanced noise-reducing air nozzles, and measure changes in sound levels to assess the effectiveness of the advanced nozzles as engineering controls for noise. Ten different R&D manufacturing areas that used compressed air guns were identified and included in the study. A-weighted sound level and Z-weighted octave band measurements were taken simultaneously using a single instrument. In each area, three sets of measurements, each lasting for 20 sec, were taken 1 m away and perpendicular to the air stream of the conventional air gun while a worker simulated typical air gun work use. Two different advanced noise-reducing air nozzles were then installed. Sound level and octave band data were collected for each of these nozzles using the same methods as for the original air guns. Both of the advanced nozzles provided sound level reductions of about 7 dBA, on average. The highest noise reductions measured were 17.2 dBA for one model and 17.7 dBA for the other. In two areas, the advanced nozzles yielded no sound level reduction, or they produced small increases in sound level. The octave band data showed strong similarities in sound level among all air gun nozzles within the 10-1,000 Hz frequency range. However, the advanced air nozzles generally had lower noise contributions in the 1,000-20,000 Hz range. The observed decreases at these higher frequencies caused the overall sound level reductions that were measured. Installing new advanced noise-reducing air nozzles can provide large sound level reductions in comparison to existing conventional nozzles, which has direct benefit for hearing conservation efforts.

24 CFR 3280.406 - Air chamber test method for certification and qualification of formaldehyde emission levels.

Code of Federal Regulations, 2010 CFR

2010-04-01

... particleboard is produced or surface-finished, whichever is later, the panels must be dead-stacked or air-tight... with the Standard Test Method for Determining Formaldehyde Levels from Wood Products Under Defined Test...

Optimal background matching camouflage.

PubMed

Michalis, Constantine; Scott-Samuel, Nicholas E; Gibson, David P; Cuthill, Innes C

2017-07-12

Background matching is the most familiar and widespread camouflage strategy: avoiding detection by having a similar colour and pattern to the background. Optimizing background matching is straightforward in a homogeneous environment, or when the habitat has very distinct sub-types and there is divergent selection leading to polymorphism. However, most backgrounds have continuous variation in colour and texture, so what is the best solution? Not all samples of the background are likely to be equally inconspicuous, and laboratory experiments on birds and humans support this view. Theory suggests that the most probable background sample (in the statistical sense), at the size of the prey, would, on average, be the most cryptic. We present an analysis, based on realistic assumptions about low-level vision, that estimates the distribution of background colours and visual textures, and predicts the best camouflage. We present data from a field experiment that tests and supports our predictions, using artificial moth-like targets under bird predation. Additionally, we present analogous data for humans, under tightly controlled viewing conditions, searching for targets on a computer screen. These data show that, in the absence of predator learning, the best single camouflage pattern for heterogeneous backgrounds is the most probable sample. © 2017 The Authors.

Variation in airborne 137Cs peak levels with altitude from high-altitude locations across Europe after the arrival of Fukushima-labeled air masses

NASA Astrophysics Data System (ADS)

Masson, Olivier; Bieringer, Jacqueline; Dalheimer, Axel; Estier, Sybille; Evrard, Olivier; Penev, Ilia; Ringer, Wolfgang; Schlosser, Clemens; Steinkopff, Thomas; Tositti, Laura; de Vismes-Ott, Anne

2015-04-01

During the Fukushima Daiichi nuclear power plant (FDNPP) accident, a dozen of high-altitude aerosol sampling stations, located between 850 and 3,454 m above sea level (a.s.l.), provided airborne activity levels across Europe (Fig. 1). This represents at most 5% of the total number of aerosol sampling locations that delivered airborne activity levels (at least one result) in Europe, in connection with this nuclear accident. High altitude stations are typically equipped with a high volume sampler that collects aerosols on filters. The Fukushima-labeled air mass arrival and the peak of airborne cesium-137 (137Cs) activity levels were registered in Europe at different dates depending on the location, with differences up to a factor of six on a regional scale. Besides this statement related to lowland areas, we have compared the maximum airborne levels registered at high-altitude European locations (850 m < altitudes < 3450 m) with what was observed at the closest lowland location. The vertical distribution of 137Cs peak level was not uniform even after a long travel time/distance from Japan. This being true at least in the atmospheric boundary layer and in the lower free troposphere. Moreover the relation '137Csmax vs. altitude' shows a decreasing trend (Fig. 2). Results and discussion : Comparison of 137Cs and 7Be levels shows simultaneous increases at least when the 137Cs airborne level rose for the first time (Fig. 3). Zugspitze and Jungfraujoch stations attest of a time shift between 7Be and 137Cs peak that can be due to the particular dynamic of air movements at such high altitudes. After the 137Cs peak value, the plume concentration decreased whatever the 7Be level. Due to the cosmogenic origin of 7Be, its increase in the ground-level air is usually associated with downwind air movements, i.e. stratospheric air intrusions or at least air from high-tropospheric levels, into lower atmospheric layers. This means that Fukushima-labeled air masses registered at ground

Randomized Trial to Reduce Air Particle Levels in Homes of Smokers and Children.

PubMed

Hughes, Suzanne C; Bellettiere, John; Nguyen, Benjamin; Liles, Sandy; Klepeis, Neil E; Quintana, Penelope J E; Berardi, Vincent; Obayashi, Saori; Bradley, Savannah; Hofstetter, C Richard; Hovell, Melbourne F

2018-03-01

Exposure to fine particulate matter in the home from sources such as smoking, cooking, and cleaning may put residents, especially children, at risk for detrimental health effects. A randomized clinical trial was conducted from 2011 to 2016 to determine whether real-time feedback in the home plus brief coaching of parents or guardians could reduce fine particle levels in homes with smokers and children. A randomized trial with two groups-intervention and control. A total of 298 participants from predominantly low-income households with an adult smoker and a child aged <14 years. Participants were recruited during 2012-2015 from multiple sources in San Diego, mainly Women, Infants and Children Program sites. The multicomponent intervention consisted of continuous lights and brief sound alerts based on fine particle levels in real time and four brief coaching sessions using particle level graphs and motivational interviewing techniques. Motivational interviewing coaching focused on particle reduction to protect children and other occupants from elevated particle levels, especially from tobacco-related sources. In-home air particle levels were measured by laser particle counters continuously in both study groups. The two outcomes were daily mean particle counts and percentage time with high particle concentrations (>15,000 particles/0.01 ft 3 ). Linear mixed models were used to analyze the differential change in the outcomes over time by group, during 2016-2017. Intervention homes had significantly larger reductions than controls in daily geometric mean particle concentrations (18.8% reduction vs 6.5% reduction, p<0.001). Intervention homes' average percentage time with high particle concentrations decreased 45.1% compared with a 4.2% increase among controls (difference between groups p<0.001). Real-time feedback for air particle levels and brief coaching can reduce fine particle levels in homes with smokers and young children. Results set the stage for refining

Physiologic correlates to background noise acceptance

NASA Astrophysics Data System (ADS)

Tampas, Joanna; Harkrider, Ashley; Nabelek, Anna

2004-05-01

Acceptance of background noise can be evaluated by having listeners indicate the highest background noise level (BNL) they are willing to accept while following the words of a story presented at their most comfortable listening level (MCL). The difference between the selected MCL and BNL is termed the acceptable noise level (ANL). One of the consistent findings in previous studies of ANL is large intersubject variability in acceptance of background noise. This variability is not related to age, gender, hearing sensitivity, personality, type of background noise, or speech perception in noise performance. The purpose of the current experiment was to determine if individual differences in physiological activity measured from the peripheral and central auditory systems of young female adults with normal hearing can account for the variability observed in ANL. Correlations between ANL and various physiological responses, including spontaneous, click-evoked, and distortion-product otoacoustic emissions, auditory brainstem and middle latency evoked potentials, and electroencephalography will be presented. Results may increase understanding of the regions of the auditory system that contribute to individual noise acceptance.

Radiological air quality in a depleted uranium storage vault

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

Robinson, T.; Cucchiara, A.L.

1999-03-01

The radiological air quality of two storage vaults, one with depleted uranium (DU) and one without, was evaluated and compared. The intent of the study was to determine if the presence of stored DU would significantly contribute to the gaseous/airborne radiation level compared to natural background. Both vaults are constructed out of concrete and are dimensionally similar. The vaults are located on the first floor of the same building. Neither vault has air supply or air exhaust. The doors to both vaults remained closed during the evaluation period, except for brief and infrequent access by the operational group. One vaultmore » contained 700 KG of depleted uranium, and the other vault contained documents inside of file cabinets. Radon detectors and giraffe air samplers were used to gather data on the quantity of gaseous/airborne radionuclides in both vaults. The results of this study indicated that there was no significant difference in the quantity of gaseous/airborne radionuclides in the two vaults. This paper gives a discussion of the effects of the stored DU on the air quality, and poses several theories supporting the results.« less

Air Force F-22 Fighter Program: Background and Issues for Congress

DTIC Science & Technology

2009-12-22

comprises a large share of their overall business.23 The Air Force in 2007 estimated that of about 1,000 first-tier F-22 supplier firms, roughly 110, or...fighter.37 In addition, Boeing, the manufacturer of the F-15, is offering for sale on the international market an upgraded version of the F-15 called...Personally I have no interest in the Silent Eagle because it is only stealthy from the front,” Hirata says, referencing a limitation shared by the

Synthetic fiber production facilities: Background information for proposed standards

NASA Astrophysics Data System (ADS)

Goodwin, D. R.

1982-10-01

Standards of performance to control emissions of volatile organic compounds (VOC) from new, modified, and reconstructed synthetic fiber production facilities are being proposed under section III of the Clean Air Act. This document contains information on the background and authority, regulatory alternatives considered, and environmental and economic impacts of the regulatory alternatives.

Association between State Assistance on the Topic of Indoor Air Quality and School District-Level Policies That Promote Indoor Air Quality in Schools

ERIC Educational Resources Information Center

Everett Jones, Sherry; Doroski, Brenda; Glick, Sherry

2015-01-01

Nationally representative data from the 2012 School Health Policies and Practices Study examined whether state assistance on indoor air quality (IAQ) was associated with district-level policies and practices related to IAQ and integrated pest management (IPM). Districts in states that provided assistance on IAQ were more likely than districts not…

Using satellite observations in performance evaluation for regulatory air quality modeling: Comparison with ground-level measurements

NASA Astrophysics Data System (ADS)

Odman, M. T.; Hu, Y.; Russell, A.; Chai, T.; Lee, P.; Shankar, U.; Boylan, J.

2012-12-01

Regulatory air quality modeling, such as State Implementation Plan (SIP) modeling, requires that model performance meets recommended criteria in the base-year simulations using period-specific, estimated emissions. The goal of the performance evaluation is to assure that the base-year modeling accurately captures the observed chemical reality of the lower troposphere. Any significant deficiencies found in the performance evaluation must be corrected before any base-case (with typical emissions) and future-year modeling is conducted. Corrections are usually made to model inputs such as emission-rate estimates or meteorology and/or to the air quality model itself, in modules that describe specific processes. Use of ground-level measurements that follow approved protocols is recommended for evaluating model performance. However, ground-level monitoring networks are spatially sparse, especially for particulate matter. Satellite retrievals of atmospheric chemical properties such as aerosol optical depth (AOD) provide spatial coverage that can compensate for the sparseness of ground-level measurements. Satellite retrievals can also help diagnose potential model or data problems in the upper troposphere. It is possible to achieve good model performance near the ground, but have, for example, erroneous sources or sinks in the upper troposphere that may result in misleading and unrealistic responses to emission reductions. Despite these advantages, satellite retrievals are rarely used in model performance evaluation, especially for regulatory modeling purposes, due to the high uncertainty in retrievals associated with various contaminations, for example by clouds. In this study, 2007 was selected as the base year for SIP modeling in the southeastern U.S. Performance of the Community Multiscale Air Quality (CMAQ) model, at a 12-km horizontal resolution, for this annual simulation is evaluated using both recommended ground-level measurements and non-traditional satellite

A feasibility study on assessing public health impacts of cumulative air pollution reduction activities in a small geographic area

EPA Science Inventory

Background and Objective: The rnain objective ofthis study was to examine the feasibility ofconducting a local (e.g., city level) assessment ofthe public health impacts ofcumulative air pollution reduction activities (a.k.a. accountability) from the federal, state, local and vo...

Air Quality Criteria for Lead (First External Review Draft)

EPA Science Inventory

Background:

The Clean Air Act mandates periodic review of the National Ambient Air Quality Standards (NAAQS) for six common air pollutants, also referred to as criteria pollutants, including lead. Under the review process, EPA's Office of Research and Development d...

Air pollution and subclinical airway inflammation in the SALIA cohort study

PubMed Central

2014-01-01

Background The association between long-term exposure to air pollution and local inflammation in the lung has rarely been investigated in the general population of elderly subjects before. We investigated this association in a population-based cohort of elderly women from Germany. Methods In a follow-up examination of the SALIA cohort study in 2008/2009, 402 women aged 68 to 79 years from the Ruhr Area and Borken (Germany) were clinically examined. Inflammatory markers were determined in exhaled breath condensate (EBC) and in induced sputum (IS). We used traffic indicators and measured air pollutants at single monitoring stations in the study area to assess individual traffic exposure and long-term air pollution background exposure. Additionally long-term residential exposure to air pollution was estimated using land-use regression (LUR) models. We applied multiple logistic and linear regression analyses adjusted for age, indoor mould, smoking, passive smoking and socio-economic status and additionally conducted sensitivity analyses. Results Inflammatory markers showed a high variability between the individuals and were higher with higher exposure to air pollution. NO derivatives, leukotriene (LT) B4 and tumour necrosis factor-α (TNF-α) showed the strongest associations. An increase of 9.42 μg/m3 (interquartile range) in LUR modelled NO2 was associated with measureable LTB4 level (level with values above the detection limit) in EBC (odds ratio: 1.38, 95% CI: 1.02 -1.86) as well as with LTB4 in IS (%-change: 19%, 95% CI: 7% - 32%). The results remained consistent after exclusion of subpopulations with risk factors for inflammation (smoking, respiratory diseases, mould infestation) and after extension of models with additional adjustment for season of examination, mass of IS and urban/rural living as sensitivity analyses. Conclusions In this analysis of the SALIA study we found that long-term exposure to air pollutants from traffic and industrial sources was

Airborne Multiangle SpectroPolarimetric Imager (AirMSPI) Level 1B2 V006 Announcement

Atmospheric Science Data Center

2018-05-22

The NASA Langley Atmospheric Science Data Center (ASDC) and Jet Propulsion Laboratory (JPL) announce the public ... SpectroPolarimetric Imager (AirMSPI) Level 1B2 V006 data for all targets acquired for flight campaigns: Radar Definition ... Experiment (RADEX) flight campaign was based out of Joint Base Lewis-McChord, Washington. The campaign focused on characterizing new ...

Air Conditioning and Heating Technology--II.

ERIC Educational Resources Information Center

Gattone, Felix

Twenty-eight chapters and numerous drawings provide information for instructors and students of air conditioning and heating technology. Chapter 1 lists the occupational opportunities in the field. Chapter 2 covers the background or development of the industry of air conditioning and heating technology. Chapter 3 includes some of the principle…

On evaluating compliance with air pollution levels 'not to be exceeded more than once per year'

NASA Technical Reports Server (NTRS)

Neustadter, H. E.; Sidik, S. M.

1974-01-01

The point of view taken is that the Environmental Protection Agency (EPA) Air Quality Standards (AQS) represent conditions which must be made to exist in the ambient environment. The statistical techniques developed should serve as tools for measuring the closeness to achieving the desired quality of air. It is shown that the sampling frequency recommended by EPA is inadequate to meet these objectives when the standard is expressed as a level not to be exceeded more than once per year and sampling frequency is once every three days or less frequent.

BOREAS AFM-5 Level-2 Upper Air Network Standard Pressure Level Data

NASA Technical Reports Server (NTRS)

Barr, Alan; Hrynkiw, Charmaine; Hall, Forrest G. (Editor); Newcomer, Jeffrey A. (Editor); Smith, David E. (Technical Monitor)

2000-01-01

The BOREAS AFM-5 team collected and processed data from the numerous radiosonde flights during the project. The goals of the AFM-05 team were to provide large-scale definition of the atmosphere by supplementing the existing AES aerological network, both temporally and spatially. This data set includes basic upper-air parameters interpolated at 0.5 kiloPascal increments of atmospheric pressure from data collected from the network of upper-air stations during the 1993, 1994, and 1996 field campaigns over the entire study region. The data are contained in tabular ASCII files. The data files are available on a CD-ROM (see document number 20010000884) or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

Level crossing analysis of cosmic microwave background radiation: a method for detecting cosmic strings

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

Movahed, M. Sadegh; Khosravi, Shahram, E-mail: m.s.movahed@ipm.ir, E-mail: khosravi@ipm.ir

2011-03-01

In this paper we study the footprint of cosmic string as the topological defects in the very early universe on the cosmic microwave background radiation. We develop the method of level crossing analysis in the context of the well-known Kaiser-Stebbins phenomenon for exploring the signature of cosmic strings. We simulate a Gaussian map by using the best fit parameter given by WMAP-7 and then superimpose cosmic strings effects on it as an incoherent and active fluctuations. In order to investigate the capability of our method to detect the cosmic strings for the various values of tension, Gμ, a simulated puremore » Gaussian map is compared with that of including cosmic strings. Based on the level crossing analysis, the superimposed cosmic string with Gμ∼>4 × 10{sup −9} in the simulated map without instrumental noise and the resolution R = 1' could be detected. In the presence of anticipated instrumental noise the lower bound increases just up to Gμ∼>5.8 × 10{sup −9}.« less

Particulate Matter Levels in Ambient Air Adjacent to Industrial Area

NASA Astrophysics Data System (ADS)

Mohamed, R. M. S. R.; Nizam, N. M. S.; Al-Gheethi, A. A.; Lajis, A.; Kassim, A. H. M.

2016-07-01

Air quality in the residential areas adjacent to the industrial regions is of great concern due to the association with human health risks. In this work, the concentrations of particulate matter (PM10) in the ambient air of UTHM campus was investigated tostudy the air qualityand their compliance to the Malaysian Ambient Air Quality Guidelines (AAQG). The PM10 samples were taken over 24 hours from the most significant area at UTHM including Stadium, KolejKediamanTunDr. Ismail (KKTDI) and MakmalBahan. The meteorological parameters; temperature, relative humidity, wind speed and wind direction as well as particulate matterwere estimated by using E-Sampler Particulate Matter (PM10) Collector. The highest concentrations of PM10 (55.56 µg/m3) was recorded at MakmalBahan during the working and weekend days. However, these concentrations are less than 150 pg/m3. It can be concluded that although UTHM is surrounded by the industrial area, the air quality in the campus still within the standards limits.

The AIRE -230Y Polymorphism Affects AIRE Transcriptional Activity: Potential Influence on AIRE Function in the Thymus

PubMed Central

Lovewell, Thomas R. J.; McDonagh, Andrew J.; Messenger, Andrew G.; Azzouz, Mimoun; Tazi-Ahnini, Rachid

2015-01-01

Background The autoimmune regulator (AIRE) is expressed in the thymus, particularly in thymic medullary epithelial cells (mTECs), and is required for the ectopic expression of a diverse range of peripheral tissue antigens by mTECs, facilitating their ability to perform negative selection of auto-reactive immature T-cells. The expression profile of peripheral tissue antigens is affected not only by AIRE deficiency but also with variation of AIRE activity in the thymus. Method and Results Therefore we screened 591bp upstream of the AIRE transcription start site including AIRE minimal promoter for single nucleotide polymorphism (SNPs) and identified two SNPs -655R (rs117557896) and -230Y (rs751032) respectively. To study the effect of these variations on AIRE promoter activity we generated a Flp-In host cell line which was stably transfected with a single copy of the reporter vector. Relative promoter activity was estimated by comparing the luciferase specific activity for lysates of the different reporter AIRE promoter-reporter gene constructs including AIRE-655G AIRE-230C, AIRE-655G AIRE-230T and AIRE-655A AIRE-230C. The analysis showed that the commonest haplotype AIRE-655G AIRE-230C has the highest luciferase specific activity (p<0.001). Whereas AIRE-655G AIRE-230T has a luciferase specific activity value that approaches null. Both AIRE promoter polymorphic sites have one allele that forms a CpG methylation site which we determined can be methylated in methylation assays using the M.SssI CpG methyltransferase. Conclusion AIRE-230Y is in a conserved region of the promoter and is adjacent to a predicted WT1 transcription factor binding site, suggesting that AIRE-230Y affects AIRE expression by influencing the binding of biochemical factors to this region. Our findings show that AIRE-655GAIRE-230T haplotype could dramatically alter AIRE transcription and so have an effect on the process of negative selection and affect susceptibility to autoimmune conditions. PMID

Methane mole fraction and δ13C above and below the trade wind inversion at Ascension Island in air sampled by aerial robotics

NASA Astrophysics Data System (ADS)

Brownlow, R.; Lowry, D.; Thomas, R. M.; Fisher, R. E.; France, J. L.; Cain, M.; Richardson, T. S.; Greatwood, C.; Freer, J.; Pyle, J. A.; MacKenzie, A. R.; Nisbet, E. G.

2016-11-01

Ascension Island is a remote South Atlantic equatorial site, ideal for monitoring tropical background CH4. In September 2014 and July 2015, octocopters were used to collect air samples in Tedlar bags from different heights above and below the well-defined Trade Wind Inversion (TWI), sampling a maximum altitude of 2700 m above mean sea level. Sampling captured both remote air in the marine boundary layer below the TWI and also air masses above the TWI that had been lofted by convective systems in the African tropics. Air above the TWI was characterized by higher CH4, but no distinct shift in δ13C was observed compared to the air below. Back trajectories indicate that lofted CH4 emissions from Southern Hemisphere Africa have bulk δ13CCH4 signatures similar to background, suggesting mixed emissions from wetlands, agriculture, and biomass burning. The campaigns illustrate the usefulness of unmanned aerial system sampling and Ascension's value for atmospheric measurement in an understudied region.

Natural air leak test without submergence for spontaneous pneumothorax.

PubMed

Uramoto, Hidetaka; Tanaka, Fumihiro

2011-12-24

Postoperative air leaks are frequent complications after surgery for a spontaneous pneumothorax (SP). We herein describe a new method to test for air leaks by using a transparent film and thoracic tube in a closed system. Between 2005 and 2010, 35 patients underwent a novel method for evaluating air leaks without submergence, and their clinical records were retrospectively reviewed. The data on patient characteristics, surgical details, and perioperative outcomes were analyzed. The differences in the clinical background and intraoperative factors did not reach a statistically significant level between the new and classical methods. The incidence of recurrence was also equivalent to the standard method. However, the length of the operation and drainage periods were significantly shorter in patients evaluated using the new method than the conventional method. Further, no postoperative complications were observed in patients evaluated using the new method. This simple technique is satisfactorily effective and does not result in any complications.

Background field removal using a region adaptive kernel for quantitative susceptibility mapping of human brain

NASA Astrophysics Data System (ADS)

Fang, Jinsheng; Bao, Lijun; Li, Xu; van Zijl, Peter C. M.; Chen, Zhong

2017-08-01

Background field removal is an important MR phase preprocessing step for quantitative susceptibility mapping (QSM). It separates the local field induced by tissue magnetic susceptibility sources from the background field generated by sources outside a region of interest, e.g. brain, such as air-tissue interface. In the vicinity of air-tissue boundary, e.g. skull and paranasal sinuses, where large susceptibility variations exist, present background field removal methods are usually insufficient and these regions often need to be excluded by brain mask erosion at the expense of losing information of local field and thus susceptibility measures in these regions. In this paper, we propose an extension to the variable-kernel sophisticated harmonic artifact reduction for phase data (V-SHARP) background field removal method using a region adaptive kernel (R-SHARP), in which a scalable spherical Gaussian kernel (SGK) is employed with its kernel radius and weights adjustable according to an energy "functional" reflecting the magnitude of field variation. Such an energy functional is defined in terms of a contour and two fitting functions incorporating regularization terms, from which a curve evolution model in level set formation is derived for energy minimization. We utilize it to detect regions of with a large field gradient caused by strong susceptibility variation. In such regions, the SGK will have a small radius and high weight at the sphere center in a manner adaptive to the voxel energy of the field perturbation. Using the proposed method, the background field generated from external sources can be effectively removed to get a more accurate estimation of the local field and thus of the QSM dipole inversion to map local tissue susceptibility sources. Numerical simulation, phantom and in vivo human brain data demonstrate improved performance of R-SHARP compared to V-SHARP and RESHARP (regularization enabled SHARP) methods, even when the whole paranasal sinus regions

Fibrin clot structure is affected by levels of particulate air pollution exposure in patients with venous thrombosis.

PubMed

Pan, Xiaoxi; Gong, Yun Yun; Martinelli, Ida; Angelici, Laura; Favero, Chiara; Bertazzi, Pier Alberto; Mannucci, Pier M; Ariëns, Robert A S; Routledge, Michael N

2016-01-01

Particulate air pollution is a risk factor for cardiovascular diseases and thrombosis. Long-term exposure to particulate matter with a diameter<10μm (PM10) has been associated with an increased risk of venous thrombosis. The aim of this study was to investigate whether or not particulate air pollution alters fibrin clot structure and thus modulates thrombosis risk. We investigated fibrin polymerization by turbidity (maximum absorbance mOD), clot structure by confocal microscopy (fibre number per μm) and fibrin pore size by permeability (Ks×10(-10)cm(2)) in 103 patients with deep vein thrombosis and 121 healthy controls, for whom levels of air pollution exposure had been recorded. Exposure groups were defined by mean PM10 concentrations over the 730days before the event. We found a higher average number of fibres per clot area in patients than controls, but no difference in Ks or fibre thickness. When the two groups were divided into high or low exposure to PM10, a significantly denser fibrin clot network structure with thicker fibres (higher maximum absorbance, p<0.05), decreased permeability (lower Ks value, p<0.05) and higher average fibre numbers per clot area (p<0.05) was observed in patients in the high exposure group compared to those with low exposure. There were no significant differences in fibrin clot structure between the two exposure levels in healthy subjects. PM10 levels are associated with altered fibrin clot structure in patients with deep vein thrombosis but not in controls, suggesting that air pollution may trigger differences in fibrin clot structure only in patients predisposed to thrombotic disease. Copyright © 2016 Elsevier Ltd. All rights reserved.

ETS levels in hospitality environments satisfying ASHRAE standard 62-1989: "ventilation for acceptable indoor air quality"

NASA Astrophysics Data System (ADS)

Moschandreas, D. J.; Vuilleumier, K. L.

Prior to this study, indoor air constituent levels and ventilation rates of hospitality environments had not been measured simultaneously. This investigation measured indoor Environmental Tobacco Smoke-related (ETS-related) constituent levels in two restaurants, a billiard hall and a casino. The objective of this study was to characterize ETS-related constituent levels inside hospitality environments when the ventilation rates satisfy the requirements of the ASHRAE 62-1989 Ventilation Standard. The ventilation rate of each selected hospitality environment was measured and adjusted. The study advanced only if the requirements of the ASHRAE 62-1989 Ventilation Standard - the pertinent standard of the American Society of Heating, Refrigeration and Air Conditioning Engineers - were satisfied. The supply rates of outdoor air and occupant density were measured intermittently to assure that the ventilation rate of each facility satisfied the standard under occupied conditions. Six ETS-related constituents were measured: respirable suspended particulate (RSP) matter, fluorescent particulate matter (FPM, an estimate of the ETS particle concentrations), ultraviolet particulate matter (UVPM, a second estimate of the ETS particle concentrations), solanesol, nicotine and 3-ethenylpyridine (3-EP). ETS-related constituent levels in smoking sections, non-smoking sections and outdoors were sampled daily for eight consecutive days at each hospitality environment. This study found that the difference between the concentrations of ETS-related constituents in indoor smoking and non-smoking sections was statistically significant. Differences between indoor non-smoking sections and outdoor ETS-related constituent levels were identified but were not statistically significant. Similarly, differences between weekday and weekend evenings were identified but were not statistically significant. The difference between indoor smoking sections and outdoors was statistically significant. Most

Sea level oscillations in coastal waters of the Buenos Aires province, Argentina

NASA Astrophysics Data System (ADS)

Dragani, W. C.; Mazio, C. A.; Nuñez, M. N.

2002-03-01

Sea level oscillations, with periods ranging from a few minutes to almost 2 h, have been observed at various tide stations located on the coast of Buenos Aires. Simultaneous records of sea level elevation measured in Mar de Ajó, Pinamar and Mar del Plata during 1982 have been spectrally analyzed. Significant spectral energy has been detected between 0.85 and 4.69 cycles per hour (cph) and the most energetic peaks have frequencies between 1.17 and 1.49 cph. Spectra, coherence, and phase difference have been analyzed for the most energetic event of the year. During that event, the most intensive spectral peak is at 1.17 cph for Mar de Ajó and Pinamar, and at 1.49 cph for Mar del Plata. Simultaneous total energy peaks at Mar de Ajó, Pinamar and Mar del Plata, and the coherence function estimated between Mar de Ajó and Pinamar suggests that sea level oscillations could be a regional phenomenon. The analyzed data suggest that sea level oscillations could be forced by atmospheric gravity waves associated with frontal passages.

Assessment of background particulate matter concentrations in small cities and rural locations--Prince George, Canada.

PubMed

Veira, Andreas; Jackson, Peter L; Ainslie, Bruce; Fudge, Dennis

2013-07-01

This study investigates the development and application of a simple method to calculate annual and seasonal PM2.5 and PM10 background concentrations in small cities and rural areas. The Low Pollution Sectors and Conditions (LPSC) method is based on existing measured long-term data sets and is designed for locations where particulate matter (PM) monitors are only influenced by local anthropogenic emission sources from particular wind sectors. The LPSC method combines the analysis of measured hourly meteorological data, PM concentrations, and geographical emission source distributions. PM background levels emerge from measured data for specific wind conditions, where air parcel trajectories measured at a monitoring station are assumed to have passed over geographic sectors with negligible local emissions. Seasonal and annual background levels were estimated for two monitoring stations in Prince George, Canada, and the method was also applied to four other small cities (Burns Lake, Houston, Quesnel, Smithers) in northern British Columbia. The analysis showed reasonable background concentrations for both monitoring stations in Prince George, whereas annual PM10 background concentrations at two of the other locations and PM2.5 background concentrations at one other location were implausibly high. For those locations where the LPSC method was successful, annual background levels ranged between 1.8 +/- 0.1 microg/m3 and 2.5 +/- 0.1 microg/m3 for PM2.5 and between 6.3 +/- 0.3 microg/m3 and 8.5 +/- 0.3 microg/m3 for PM10. Precipitation effects and patterns of seasonal variability in the estimated background concentrations were detectable for all locations where the method was successful. Overall the method was dependent on the configuration of local geography and sources with respect to the monitoring location, and may fail at some locations and under some conditions. Where applicable, the LPSC method can provide a fast and cost-efficient way to estimate background PM

Advanced Background Subtraction Applied to Aeroacoustic Wind Tunnel Testing

NASA Technical Reports Server (NTRS)

Bahr, Christopher J.; Horne, William C.

2015-01-01

An advanced form of background subtraction is presented and applied to aeroacoustic wind tunnel data. A variant of this method has seen use in other fields such as climatology and medical imaging. The technique, based on an eigenvalue decomposition of the background noise cross-spectral matrix, is robust against situations where isolated background auto-spectral levels are measured to be higher than levels of combined source and background signals. It also provides an alternate estimate of the cross-spectrum, which previously might have poor definition for low signal-to-noise ratio measurements. Simulated results indicate similar performance to conventional background subtraction when the subtracted spectra are weaker than the true contaminating background levels. Superior performance is observed when the subtracted spectra are stronger than the true contaminating background levels. Experimental results show limited success in recovering signal behavior for data where conventional background subtraction fails. They also demonstrate the new subtraction technique's ability to maintain a proper coherence relationship in the modified cross-spectral matrix. Beam-forming and de-convolution results indicate the method can successfully separate sources. Results also show a reduced need for the use of diagonal removal in phased array processing, at least for the limited data sets considered.

The Association of Ambient Air Pollution and Physical Inactivity in the United States

PubMed Central

Roberts, Jennifer D.; Voss, Jameson D.; Knight, Brandon

2014-01-01

Background Physical inactivity, ambient air pollution and obesity are modifiable risk factors for non-communicable diseases, with the first accounting for 10% of premature deaths worldwide. Although community level interventions may target each simultaneously, research on the relationship between these risk factors is lacking. Objectives After comparing spatial interpolation methods to determine the best predictor for particulate matter (PM2.5; PM10) and ozone (O3) exposures throughout the U.S., we evaluated the cross-sectional association of ambient air pollution with leisure-time physical inactivity among adults. Methods In this cross-sectional study, we assessed leisure-time physical inactivity using individual self-reported survey data from the Centers for Disease Control and Prevention's 2011 Behavioral Risk Factor Surveillance System. These data were combined with county-level U.S. Environmental Protection Agency air pollution exposure estimates using two interpolation methods (Inverse Distance Weighting and Empirical Bayesian Kriging). Finally, we evaluated whether those exposed to higher levels of air pollution were less active by performing logistic regression, adjusting for demographic and behavioral risk factors, and after stratifying by body weight category. Results With Empirical Bayesian Kriging air pollution values, we estimated a statistically significant 16–35% relative increase in the odds of leisure-time physical inactivity per exposure class increase of PM2.5 in the fully adjusted model across the normal weight respondents (p-value<0.0001). Evidence suggested a relationship between the increasing dose of PM2.5 exposure and the increasing odds of physical inactivity. Conclusions In a nationally representative, cross-sectional sample, increased community level air pollution is associated with reduced leisure-time physical activity particularly among the normal weight. Although our design precludes a causal inference, these results provide

Estimation of background noise level on seismic station using statistical analysis for improved analysis accuracy

NASA Astrophysics Data System (ADS)

Han, S. M.; Hahm, I.

2015-12-01

We evaluated the background noise level of seismic stations in order to collect the observation data of high quality and produce accurate seismic information. Determining of the background noise level was used PSD (Power Spectral Density) method by McNamara and Buland (2004) in this study. This method that used long-term data is influenced by not only innate electronic noise of sensor and a pulse wave resulting from stabilizing but also missing data and controlled by the specified frequency which is affected by the irregular signals without site characteristics. It is hard and inefficient to implement process that filters out the abnormal signal within the automated system. To solve these problems, we devised a method for extracting the data which normally distributed with 90 to 99% confidence intervals at each period. The availability of the method was verified using 62-seismic stations with broadband and short-period sensors operated by the KMA (Korea Meteorological Administration). Evaluation standards were NHNM (New High Noise Model) and NLNM (New Low Noise Model) published by the USGS (United States Geological Survey). It was designed based on the western United States. However, Korean Peninsula surrounded by the ocean on three sides has a complicated geological structure and a high population density. So, we re-designed an appropriate model in Korean peninsula by statistically combined result. The important feature is that secondary-microseism peak appeared at a higher frequency band. Acknowledgements: This research was carried out as a part of "Research for the Meteorological and Earthquake Observation Technology and Its Application" supported by the 2015 National Institute of Meteorological Research (NIMR) in the Korea Meteorological Administration.

Relationships between Hg Air-surface exchange, Soil Moisture and Precipitation at a Background Vegetated Site in South-Eastern Australia.

NASA Astrophysics Data System (ADS)

Macsween, K.; Edwards, G. C.

2017-12-01

Despite many decades of research, the controlling mechanisms of mercury (Hg) air-surface exhange are still poorly understood. Particularly in Australian ecosystems where there are few anthropogenic inputs. A clear understanding of these mechanisms is vital for accurate representation in the global Hg models, particularly regarding re-emission. Water is known to have a considerable influence on Hg exchange within a terrestrial ecosystem. Precipitation has been found to cause spikes is Hg emissions during the initial stages of rain event. While, Soil moisture content is known to enhance fluxes between 15 and 30% Volumetric soil water (VSW), above which fluxes become suppressed. Few field experiments exist to verify these dominantly laboratory or controlled experiments. Here we present work looking at Hg fluxes over an 8-month period at a vegetated background site. The aim of this study is to identify how changes to precipitation intensity and duration, coupled with variable soil moisture content may influence Hg flux across seasons. As well as the influence of other meteorological variables. Experimentation was undertaken using aerodynamic gradient micrometeorological flux method, avoiding disruption to the surface, soil moisture probes and rain gauge measurements to monitor alterations to substrate conditions. Meteorological and air chemistry variables were also measured concurrently throughout the duration of the study. During the study period, South-Eastern Australia experienced several intense east coast low storm systems during the Autumn and Spring months and an unusually dry winter. VSW rarely reached above 30% even following the intense rainfall experienced during the east coast lows. The generally dry conditions throughout winter resulted in an initial spike in Hg emissions when rainfall occurred. Fluxes decreased shortly after the rain began but remained slightly elevated. Given the reduced net radiation and cooler temperatures experienced during the winter

Air pollution and cardiovascular and respiratory disease: Rationale and methodology of CAPACITY study

PubMed Central

Rabiei, Katayoun; Hosseini, Sayed Mohsen; Sadeghi, Erfan; Jafari-Koshki, Tohid; Rahimi, Mojtaba; Shishehforoush, Mansour; Lahijanzadeh, Ahmadreza; Sadeghian, Babak; Moazam, Elham; Mohebi, Mohammad Bagher; Ezatian, Victoria; Sarrafzadegan, Nizal

2017-01-01

BACKGROUND Considering the high level of air pollution and its impact on health, we aimed to study the correlation of air pollution with hospitalization and mortality of cardiovascular (CVD) and respiratory diseases (ResD) (CAPACITY) to determine the effects of air pollutants on CVD and ResD hospitalizations and deaths in Isfahan, Iran. METHODS Hourly levels of air pollutants including particulate matter (PM), carbon monoxide (CO), nitrogen dioxide (NO2), sulfur dioxide (SO2), and ozone (O3), information of CVD and ResD admissions and death certificate were obtained respectively from Department of Environment (DOE), Iran, hospitals and cemetery. Time series and case-crossover model were used to find the impact of air pollutants. This paper only summarizes the descriptive findings of the CAPACITY study. RESULTS The total number of hospitalized patients were 23781 in 2010 and 22485 in 2011. The most frequent cause of hospitalization and death was ischemic heart diseases in both years. While the mean annual levels of O3, CO, and PM10 were lower in 2011 than in 2010, NO2 and SO2 levels higher in 2011. In both years, PM10 was similarly increased during last month of fall, late spring and early summer. In 2011, the PM2.5 and PM10 monthly trend of change were similar. CONCLUSION The CAPACITY study is one of the few large-scale studies that evaluated the effects of air pollutants on a variety of CVD and ResD in a large city of Iran. This study can provide many findings that could clarify the effects of these pollutants on the incidence and burden of both disease groups. PMID:29643921

Malondialdehyde-Deoxyguanosine Adduct Formation in Workers of Pathology Wards. The Role of Air Formaldehyde Exposure

PubMed Central

Romanazzi, Valeria; Munnia, Armelle; Piro, Sara; Allione, Alessandra; Ricceri, Fulvio; Guarrera, Simonetta; Pignata, Cristina; Matullo, Giuseppe; Wang, Poguang; Giese, Roger W.; Peluso, Marco

2010-01-01

Background Formaldehyde is a ubiquitous pollutant to which humans are exposed. Pathologists can experience high formaldehyde exposure levels. Formaldehyde – among other properties – induce oxidative stress and free radicals, which react with DNA and lipids, leading to oxidative damage and lipid peroxidation, respectively. We measured the levels of air-formaldehyde exposure in a group of Italian pathologists and controls. We analyzed the effect of formaldehyde exposure on leukocyte malondialdehyde-deoxyguanosine adducts (M1-dG), a biomarker of oxidative stress and lipid peroxidation. We studied the relationship between air-formaldehyde and M1-dG adducts. Methods Air-formaldehyde levels were measured by personal air samplers. M1-dG adducts were analyzed by 32P-postlabelling assay. Results Reduction rooms pathologists were significantly exposed to air-formaldehyde in respect to controls and to the pathologists working in other laboratory areas (p<0.001). A significant difference for M1-dG adducts between exposed pathologists and controls was found (p=0.045). The effect becomes stronger when the evaluation of air-formaldehyde exposure was based on personal samplers (p=0.018). Increased M1dG adduct levels were only found in individuals exposed to air-formaldehyde concentrations higher than 66 μg/m3. When the exposed workers and controls were subgrouped according to smoking, M1-dG tended to increase in all the subjects but a significant association between M1-dG and air-formaldehyde was only found in not smokers (p= 0.009). Air formaldehyde played a role positive but not significant (r = 0.355, p = 0.075, Pearson correlation) in the formation of M1-dG, only in not smokers. Conclusions Working in the reduction rooms and to be exposed to air-formaldehyde concentrations higher than 66 μg/m3 is associated with increased levels of M1-dG adducts. PMID:20707408

School-based exposure to hazardous air pollutants and grade point average: A multi-level study.

PubMed

Grineski, Sara E; Clark-Reyna, Stephanie E; Collins, Timothy W

2016-05-01

The problem of environmental health hazards around schools is serious but it has been neglected by researchers and analysts. This is concerning because children are highly susceptible to the effects of chemical hazards. Some ecological studies have demonstrated that higher school-level pollution is associated with lower aggregate school-level standardized test scores likely, related to increased respiratory illnesses and/or impaired cognitive development. However, an important question remains unexamined: How do school-level exposures impact individual children's academic performance? To address this, we obtained socio-demographic and grades data from the parents of 1888 fourth and fifth grade children in the El Paso (Texas, USA) Independent School District in 2012. El Paso is located on the US-side of the Mexican border and has a majority Mexican-origin population. School-based hazardous air pollution (HAP) exposure was calculated using census block-level US Environmental Protection Agency National Air Toxics Assessment risk estimates for respiratory and diesel particulate matter (PM). School-level demographics were obtained from the school district. Multi-level models adjusting for individual-level covariates (e.g., age, sex, race/ethnicity, English proficiency, and economic deprivation) and school-level covariates (e.g., percent of students economically disadvantaged and student-teacher ratio) showed that higher school-level HAPs were associated with lower individual-level grade point averages. An interquartile range increase in school-level HAP exposure was associated with an adjusted 0.11-0.40 point decrease in individual students' grade point averages (GPAs), depending on HAP type and emission source. Respiratory risk from HAPs had a larger effect on GPA than did diesel PM risk. Non-road mobile and total respiratory risk had the largest effects on children's GPA of all HAP variables studied and only mother's level of education had a larger effect than those

Resonant optical pulses on a continuous-wave background in two-level active media

NASA Astrophysics Data System (ADS)

Li, Sitai; Biondini, Gino; Kovačič, Gregor; Gabitov, Ildar

2018-01-01

We present exact N-soliton optical pulses riding on a continuous-wave (c.w.) beam that propagate through and interact with a two-level active optical medium. Their representation is derived via an appropriate generalization of the inverse scattering transform for the corresponding Maxwell-Bloch equations. We describe the single-soliton solutions in detail and classify them into several distinct families. In addition to the analogues of traveling-wave soliton pulses that arise in the absence of a c.w. beam, we obtain breather-like structures, periodic pulse-trains and rogue-wave-type (i.e., rational) pulses, whose existence is directly due to the presence of the c.w. beam. These soliton solutions are the analogues for Maxwell-Bloch systems of the four classical solution types of the focusing nonlinear Schrödinger equation with non-zero background, although the physical behavior of the corresponding solutions is quite different.

Apparatus having reduced background for measuring radiation activity in aerosol particles

DOEpatents

Rodgers, John C.; McFarland, Andrew R.; Oritz, Carlos A.; Marlow, William H.

1992-01-01

Apparatus having reduced background for measuring radiation activity in aerosol particles. A continuous air monitoring sampler is described for use in detecting the presence of alpha-emitting aerosol particles. An inlet fractionating screen has been demonstrated to remove about 95% of freshly formed radon progeny from the aerosol sample, and approximately 33% of partially aged progeny. Addition of an electrical condenser and a modified dichotomous virtual impactor are expected to produce considerable improvement in these numbers, the goal being to enrich the transuranic (TRU) fraction of the aerosols. This offers the possibility of improving the signal-to-noise ratio for the detected alpha-particle energy spectrum in the region of interest for detecting TRU materials associated with aerosols, thereby enhancing the performance of background-compensation algorithms for improving the quality of alarm signals intended to warn personnel of potentially harmful quantities of TRU materials in the ambient air.

DNA damage in buccal mucosa cells of pre-school children exposed to high levels of urban air pollutants.

PubMed

Ceretti, Elisabetta; Feretti, Donatella; Viola, Gaia C V; Zerbini, Ilaria; Limina, Rosa M; Zani, Claudia; Capelli, Michela; Lamera, Rossella; Donato, Francesco; Gelatti, Umberto

2014-01-01

Air pollution has been recognized as a human carcinogen. Children living in urban areas are a high-risk group, because genetic damage occurring early in life is considered able to increase the risk of carcinogenesis in adulthood. This study aimed to investigate micronuclei (MN) frequency, as a biomarker of DNA damage, in exfoliated buccal cells of pre-school children living in a town with high levels of air pollution. A sample of healthy 3-6-year-old children living in Brescia, Northern Italy, was investigated. A sample of the children's buccal mucosa cells was collected during the winter months in 2012 and 2013. DNA damage was investigated using the MN test. Children's exposure to urban air pollution was evaluated by means of a questionnaire filled in by their parents that included items on various possible sources of indoor and outdoor pollution, and the concentration of fine particulate matter (PM10, PM2.5) and NO2 in the 1-3 weeks preceding biological sample collection. 181 children (mean age ± SD: 4.3 ± 0.9 years) were investigated. The mean ± SD MN frequency was 0.29 ± 0.13%. A weak, though statistically significant, association of MN with concentration of air pollutants (PM10, PM2.5 and NO2) was found, whereas no association was apparent between MN frequency and the indoor and outdoor exposure variables investigated via the questionnaire. This study showed a high MN frequency in children living in a town with heavy air pollution in winter, higher than usually found among children living in areas with low or medium-high levels of air pollution.

Leptin levels distribution and ethnic background in two populations from Chile: Caucasian and Mapuche groups.

PubMed

Pérez-Bravo, F; Albala, C; Santos, J L; Yañez, M; Carrasco, E

1998-10-01

Leptin, the product of the human ob gene is increased in obese individuals, suggesting resistance to its effect. We examined the relationship of serum leptin levels with respect to obesity, gender and insulin levels in two populations with different ethnic compositions in Chile. Leptin and insulin levels were determined by radioimmunoassay (RIA) and correlated with body mass index (BMI), gender and ethnic background. 79 Caucasian subjects from Santiago and 65 Mapuche natives from the Araucania region, Chile, were included in this study. Leptin concentrations in obese subjects were significantly increased in both ethnic groups in relation to lean status: Caucasian and Mapuche obese 19.3 +/- 11.6 and 10.1 +/- 5.8 (P < 0.001), respectively vs Caucasian and Mapuche lean 10.4 +/- 5.8 and 4.7 +/- 2.9 (P < 0.001, respectively). When we compared Mapuche and Caucasian groups, similar leptin levels were observed among the males of the two populations in both metabolic states (lean and obese). In contrast, the leptin level distributions between women showed a marked difference, having a minor value in the Mapuche women with a comparable value with the male group in this ethnic population. The leptin concentrations are associated with obesity in both ethnic groups in Chile. However, the leptin levels between the Mapuche natives were significantly decreased compared to the Caucasian group. The gender distribution does not seem to be important in the Mapuche natives. The ethnic composition seems to be important in the leptin distribution in the analysed populations.

Meta-Prediction of the Effect of Methylenetetrahydrofolate Reductase Polymorphisms and Air Pollution on Alzheimer's Disease Risk.

PubMed

Wu, Suh-Mian; Chen, Zhao-Feng; Young, Lufei; Shiao, S Pamela K

2017-01-11

Background : Alzheimer's disease (AD) is a significant public health issue. AD has been linked with methylenetetrahydrofolate reductase ( MTHFR ) C677T polymorphism, but the findings have been inconsistent. The purpose of this meta-predictive analysis is to examine the associations between MTHFR polymorphisms and epigenetic factors, including air pollution, with AD risk using big data analytics approaches. Methods and Results : Forty-three studies (44 groups) were identified by searching various databases. MTHFR C677T TT and CT genotypes had significant associations with AD risk in all racial populations (RR = 1.13, p = 0.0047; and RR = 1.12, p < 0.0001 respectively). Meta-predictive analysis showed significant increases of percentages of MTHFR C677T polymorphism with increased air pollution levels in both AD case group and control group ( p = 0.0021-0.0457); with higher percentages of TT and CT genotypes in the AD case group than that in the control group with increased air pollution levels. Conclusions : The impact of MTHFR C677T polymorphism on susceptibility to AD was modified by level of air pollution. Future studies are needed to further examine the effects of gene-environment interactions including air pollution on AD risk for world populations.

AirMSPI Level 1B2 V006 New Data for the NASA/JPL/Caltech ImPACT-PM Campaign

Atmospheric Science Data Center

2018-05-17

AirMSPI Level 1B2 V006 New Data for the NASA/JPL/Caltech ImPACT-PM Campaign ImPACT-PM Wednesday, May 16, 2018 The NASA Langley Atmospheric Science Data Center (ASDC) and Jet Propulsion ... flight campaign.   AirMSPI flies in the nose of NASA's high-altitude ER-2 aircraft. The instrument was built by JPL and the ...

Air Quality Index (AQI) -- A Guide to Air Quality and Your Health

MedlinePlus

... Guide for Ozone Air Quality Guide for Particle Pollution Other AirNow Publications Other AirNow Publications En Español ... the Clean Air Act: ground-level ozone, particle pollution (also known as particulate matter), carbon monoxide, sulfur ...

Air Pollution Control Policies in China: A Retrospective and Prospects.

PubMed

Jin, Yana; Andersson, Henrik; Zhang, Shiqiu

2016-12-09

With China's significant role on pollution emissions and related health damage, deep and up-to-date understanding of China's air pollution policies is of worldwide relevance. Based on scientific evidence for the evolution of air pollution and the institutional background of environmental governance in China, we examine the development of air pollution control policies from the 1980s and onwards. We show that: (1) The early policies, until 2005, were ineffective at reducing emissions; (2) During 2006-2012, new instruments which interact with political incentives were introduced in the 11th Five-Year Plan, and the national goal of reducing total sulfur dioxide (SO₂) emissions by 10% was achieved. However, regional compound air pollution problems dominated by fine particulate matter (PM 2.5 ) and ground level ozone (O₃) emerged and worsened; (3) After the winter-long PM 2.5 episode in eastern China in 2013, air pollution control policies have been experiencing significant changes on multiple fronts. In this work we analyze the different policy changes, the drivers of changes and key factors influencing the effectiveness of policies in these three stages. Lessons derived from the policy evolution have implications for future studies, as well as further reforming the management scheme towards air quality and health risk oriented directions.

A comparison of individual exposure, perception, and acceptable levels of PM2.5 with air pollution policy objectives in China.

PubMed

Huang, Lei; Rao, Chao; van der Kuijp, Tsering Jan; Bi, Jun; Liu, Yang

2017-08-01

Atmospheric pollution has emerged as a major public health issue in China. Public perception and acceptable risk levels of air pollution can prompt individual behavioral changes and play a major role in the public's response to health risks. Therefore, to explore these responses and evaluate what constitutes publicly acceptable concentrations of fine particulate matter (PM 2.5 ), questionnaire surveys were conducted in three representative cities of China: Beijing, Nanjing, and Guangzhou. Great differences in public risk perception were revealed. Public perception of the health effects of air pollution (Effect) and familiarity with it (Familiarity) were significantly higher in the winter than in the summer, and also during severe haze days compared with typical days. The public perception of trust in the government (Trust) was consistent across all conditions. Exposure to severe haze pollution and experiencing harms from it were key factors influencing public willingness to respond to haze. These results reflected individual exposure levels correlating closely with risk perception and acceptance of PM 2.5 . However, a crucial gap exists between public acceptable risk levels (PARL) of air pollution and the policy objectives of the State Council's Action Plan. Thus, policymakers can utilize this study to develop more targeted measures to combat air pollution. Copyright © 2017 Elsevier Inc. All rights reserved.

Chemical trends in background air quality and the ionic composition of precipitation for the period 1980-2004 from samples collected at Valentia Observatory, Co. Kerry, Ireland.

PubMed

Bashir, Wasim; McGovern, Frank; O'Brien, Phillip; Ryan, Margaret; Burke, Liam; Paull, Brett

2008-06-01

A major Irish study, based upon more than 8000 samples collected over the measurement period of 22 years, for sulfur dioxide (SO2-S), sulfate (SO4-S) and nitrogen dioxide (NO2-N) concentrations (microg m(-3)) within air, and the ionic composition of precipitation samples based on sodium (Na+), potassium (K+), magnesium (Mg2+), calcium (Ca2+), chloride (Cl-), sulfate (SO4-S), non-sea salt sulfate (nssSO4-S), ammonium (NH4-N), and nitrate (NO3-N) weighted mean concentrations (mg l(-1)), has been completed. For the air samples, the sulfur dioxide and sulfate concentrations decreased over the sampling period (1980-2004) by 75% and 45%, respectively, whereas no significant trend was observed for nitrogen dioxide. The highest concentrations for sulfur dioxide, sulfate and nitrogen dioxide were associated with wind originating from the easterly and northeasterly directions i.e. those influenced by Irish and European sources. The lowest concentrations were associated with the westerly directions i.e. for air masses originating in the North Atlantic region. This was further verified with the use of backward (back) trajectory analysis, which allowed tracing the movement of air parcels using the European Centre for Medium range Weather Forecasting (ECMWF) ERA-40 re-analysis data. High non-sea salt sulfate levels were being associated with air masses originating from Europe (easterlies) with lower levels from the Atlantic (westerlies). With the precipitation data, analysis of the non-sea salt sulfate concentrations showed a decrease by 47% since the measurements commenced.

Effects of air transportation cause physiological and biochemical changes indicative of stress leading to regulation of chaperone expression levels and corticosterone concentration.

PubMed

Shim, SunBo; Lee, SeHyun; Kim, ChuelKyu; Kim, ByoungGuk; Jee, SeungWan; Lee, SuHae; Sin, JiSoon; Bae, ChangJoon; Woo, Jong-Min; Cho, JungSik; Lee, EonPil; Choi, HaeWook; Kim, HongSung; Lee, JaeHo; Jung, YoungJin; Cho, ByungWook; Chae, KabRyong; Hwang, DaeYoun

2009-01-01

Laboratory animals generally experience numerous unfamiliar environmental and psychological influences such as noises, temperatures, handling, shaking, and smells during the process of air transportation. To investigate whether stress induced by air transportation affects stress-related factors in animals, the levels of hormone and chaperone protein were measured in several tissues of F344 rats transported for 13 h and not transported. Herein, we conclude that the levels of corticosterone, HSP70, and GRP78 were significantly increased in the transported group compare to not transported group, but they were rapidly restored to the not transported group level after a recovery period of one week. However, the magnitude of induction and restoration levels of these factors varied depending on the tissue type. Thus, these results suggest that air transportation should be considered for the improvement of laboratory animal health and to reduce the incidence of laboratory animal stress.

Exterior view of LongTerm Oxidizer Silo (T28D) in left background ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Exterior view of Long-Term Oxidizer Silo (T-28D) in left background (taller structure) and adjacent Oxidizer Conditioning Structure (T-28B) at extreme left background, looking south. At far right in foreground is a nitrogen tank in a concrete truck well - Air Force Plant PJKS, Systems Integration Laboratory, Long-Term Oxidizer Silo, Waterton Canyon Road & Colorado Highway 121, Lakewood, Jefferson County, CO

Aerosol Optical Properties at the Lulin Atmospheric Background Station in Taiwan and the Influences of Long-Range Transport of Air Pollutants

NASA Technical Reports Server (NTRS)

Hsiao, Ta-Chih; Chen, Wei-Nai; Ye, Wei-Cheng; Lin, Neng-Huei; Tsay, Si-Chee; Lin, Tang-Huang; Lee, Chung-Te; Chuang, Ming-Tung; Pantina, Peter; Wang, Sheng-Hsiang

2016-01-01

The Lulin Atmospheric Background Station (LABS, 23.47 deg. N 120.87 deg. E, 2862 m ASL) in Central Taiwan was constructed in 2006 and is the only high-altitude background station in the western Pacific region for studying the influence of continental outflow. In this study, extensive optical properties of aerosols, including the aerosol light scattering coefficient [Sigma(sub s)] and light absorption coefficient [Sigma(sub a)], were collected from 2013 to 2014. The intensive optical properties, including mass scattering efficiency [Sigma(sub s)], mass absorption efficiency [Sigma(sub a)] single scattering albedo (Omega), scattering Angstrom exponent (A), and backscattering fraction (b), were determined and investigated, and the distinct seasonal cycle was observed. The value of [Alpha(sub a)] began to increase in January and reached a maximum in April; the mean in spring was 5.89 m(exp. 2) g(exp. -1) with a standard deviation (SD) of 4.54 m(exp. 2) g(exp. -1) and a 4.48 m(exp. 2) g(exp. -1) interquartile range (IQR: 2.95-7.43 m(exp. 2) g(exp. -1). The trend was similar in [Sigma(sub a)], with a maximum in March and a monthly mean of 0.84 m(exp. 2) g(exp. -1). The peak values of Omega (Mean = 0.92, SD = 0.03, IQR: 0.90 - 0.93) and A (Mean = 2.22, SD = 0.61, IQR: 2.12 = 2.47) occurred in autumn. These annual patterns of optical properties were associated with different long-range transport patterns of air pollutants such as biomass burning (BB) aerosol in spring and potential anthropogenic emissions in autumn. The optical measurements performed at LABS during spring in 2013 were compared with those simultaneously performed at the Doi Ang Kang Meteorology Station, Chiang Mai Province, Thailand (DAK, 19.93 deg. N, 99.05 deg. E, 1536 m a.s.l.), which is located in the Southeast Asia BB source region. Furthermore, the relationships among [Sigma(sub s)], [Sigma(sub a)], and (b) were used to characterize the potential aerosol types transported to LABS during different

Aerosol optical properties at the Lulin Atmospheric Background Station in Taiwan and the influences of long-range transport of air pollutants

NASA Astrophysics Data System (ADS)

Hsiao, Ta-Chih; Chen, Wei-Nai; Ye, Wei-Cheng; Lin, Neng-Huei; Tsay, Si-Chee; Lin, Tang-Huang; Lee, Chung-Te; Chuang, Ming-Tung; Pantina, Peter; Wang, Sheng-Hsiang

2017-02-01

The Lulin Atmospheric Background Station (LABS, 23.47°N 120.87°E, 2862 m ASL) in Central Taiwan was constructed in 2006 and is the only high-altitude background station in the western Pacific region for studying the influence of continental outflow. In this study, extensive optical properties of aerosols, including the aerosol light scattering coefficient (σs) and light absorption coefficient (σa), were collected from 2013 to 2014. The intensive optical properties, including mass scattering efficiency (αs), mass absorption efficiency (αa), single scattering albedo (ω), scattering Ångstrӧm exponent (Å), and backscattering fraction (b), were determined and investigated, and the distinct seasonal cycle was observed. The value of αs began to increase in January and reached a maximum in April; the mean in spring was 5.89 m2 g-1 with a standard deviation (SD) of 4.54 m2 g-1 and a 4.48 m2 g-1 interquartile range (IQR: 2.95-7.43 m2 g-1). The trend was similar in αa, with a maximum in March and a monthly mean of 0.84 m2 g-1. The peak values of ω (Mean = 0.92, SD = 0.03, IQR: 0.90-0.93) and Å (Mean = 2.22, SD = 0.61, IQR: 2.12-2.47) occurred in autumn. These annual patterns of optical properties were associated with different long-range transport patterns of air pollutants such as biomass burning (BB) aerosol in spring and potential anthropogenic emissions in autumn. The optical measurements performed at LABS during spring in 2013 were compared with those simultaneously performed at the Doi Ang Kang Meteorology Station, Chiang Mai Province, Thailand (DAK, 19.93°N, 99.05°E, 1536 m a.s.l.), which is located in the Southeast Asia BB source region. Furthermore, the relationships among αs, αa, and b were used to characterize the potential aerosol types transported to LABS during different seasons, and the data were inspected according to the HYSPLIT 5-day backward trajectories, which differentiate between different regions of air mass origin.

Aspergillus fumigatus and mesophilic moulds in air in the surrounding environment downwind of non-hazardous waste landfill sites.

PubMed

Schlosser, Olivier; Robert, Samuel; Debeaupuis, Catherine

2016-05-01

Non-hazardous waste landfilling has the potential to release biological agents into the air, notably mould spores. Some species, such as Aspergillus fumigatus, may be a cause of concern for at-risk nearby residents. However, air concentration in the surrounding environment of non-hazardous waste landfill sites is poorly documented. An extensive sampling programme was designed to investigate the relationship between culturable mesophilic moulds and A. fumigatus concentrations in air and distance downwind of non-hazardous waste landfill sites. On-site and off-site repeated measurements were performed at four landfill sites during cold and warm seasons. A high-flow air-sampler device was selected so as to allow peak concentration measurement. Linear mixed-effects models were used to explain variability in the concentrations in air over time and across sites, seasons, instantaneous meteorological conditions and discharged waste tonnage. Concentrations of mesophilic moulds and A. fumigatus at off-site upwind sampling locations were compared with concentrations at each of the downwind sampling locations. At the tipping face location, peak concentration reached 480,000CFUm(-3) for mesophilic moulds and 9300CFUm(-3) for A. fumigatus. Compared with upwind background levels, these concentrations were, on average, approximately 20 and 40 times higher respectively. A steep decline in the concentration of both mesophilic moulds and A. fumigatus was observed between the tipping face location and the downwind property boundary (reduction by 77% and 84% respectively), followed by a low decline leading to a 90% and 94% reduction in concentration at 200m from the property boundary and beyond. With the 200m and 500m downwind sampling point values added together, the 97.5th percentile of concentration was 6013CFUm(-3) and 87CFUm(-3) for mesophilic moulds and A. fumigatus, respectively. Other determining factors were the discharged waste tonnage, the season, instantaneous temperature

The Anisotropy of the Microwave Background to l = 3500: Deep Field Observations with the Cosmic Background Imager

NASA Technical Reports Server (NTRS)

Mason, B. S.; Pearson, T. J.; Readhead, A. C. S.; Shepherd, M. C.; Sievers, J.; Udomprasert, P. S.; Cartwright, J. K.; Farmer, A. J.; Padin, S.; Myers, S. T.;

Variation of annual effective dose due to radon level in indoor air in Marwar region of Rajasthan, India

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

Rani, Asha, E-mail: ashasachdeva78@gmail.com; Mittal, Sudhir, E-mail: sudhirmittal03@gmail.com; Mehra, Rohit

In the present work, indoor radon and thoron measurements have been carried out from different locations of Jodhpur and Nagaur districts of Northern Rajasthan, India using RAD7, a solid state alpha detector. The radon and thoron concentration in indoor air varies from 8.75 to 61.25 Bq m{sup −3} and 32.7 to 147.2 Bq m{sup −3} with the mean value of 32 and 73 Bq m{sup −3} respectively. The observed indoor radon concentration values are well below the action level recommended by International Commission on Radiological Protection (200-300 Bq m{sup −3}) and Environmental Protection Agency (148 Bq m{sup −3}). The surveymore » reveals that the thoron concentration values in the indoor air are well within the International Commission on Radiological Protection (2005). The calculated total annual effective dose due to radon level in indoor air varies from 0.22 to 1.54 mSv y{sup −1} with the mean value of 0.81 mSv y{sup −1} which is less than even the lower limit of action level 3-10 mSv y{sup −1} recommended by International Commission on Radiological Protection (2005)« less

Linking stroke mortality with air pollution, income, and greenness in northwest Florida: an ecological geographical study

PubMed Central

Hu, Zhiyong; Liebens, Johan; Rao, K Ranga

2008-01-01

Background Relatively few studies have examined the association between air pollution and stroke mortality. Inconsistent and inclusive results from existing studies on air pollution and stroke justify the need to continue to investigate the linkage between stroke and air pollution. No studies have been done to investigate the association between stroke and greenness. The objective of this study was to examine if there is association of stroke with air pollution, income and greenness in northwest Florida. Results Our study used an ecological geographical approach and dasymetric mapping technique. We adopted a Bayesian hierarchical model with a convolution prior considering five census tract specific covariates. A 95% credible set which defines an interval having a 0.95 posterior probability of containing the parameter for each covariate was calculated from Markov Chain Monte Carlo simulations. The 95% credible sets are (-0.286, -0.097) for household income, (0.034, 0.144) for traffic air pollution effect, (0.419, 1.495) for emission density of monitored point source polluters, (0.413, 1.522) for simple point density of point source polluters without emission data, and (-0.289,-0.031) for greenness. Household income and greenness show negative effects (the posterior densities primarily cover negative values). Air pollution covariates have positive effects (the 95% credible sets cover positive values). Conclusion High risk of stroke mortality was found in areas with low income level, high air pollution level, and low level of exposure to green space. PMID:18452609

Gravitoinertial force background level affects adaptation to coriolis force perturbations of reaching movements

NASA Technical Reports Server (NTRS)

Lackner, J. R.; Dizio, P.

1998-01-01

We evaluated the combined effects on reaching movements of the transient, movement-dependent Coriolis forces and the static centrifugal forces generated in a rotating environment. Specifically, we assessed the effects of comparable Coriolis force perturbations in different static force backgrounds. Two groups of subjects made reaching movements toward a just-extinguished visual target before rotation began, during 10 rpm counterclockwise rotation, and after rotation ceased. One group was seated on the axis of rotation, the other 2.23 m away. The resultant of gravity and centrifugal force on the hand was 1.0 g for the on-center group during 10 rpm rotation, and 1.031 g for the off-center group because of the 0.25 g centrifugal force present. For both groups, rightward Coriolis forces, approximately 0.2 g peak, were generated during voluntary arm movements. The endpoints and paths of the initial per-rotation movements were deviated rightward for both groups by comparable amounts. Within 10 subsequent reaches, the on-center group regained baseline accuracy and straight-line paths; however, even after 40 movements the off-center group had not resumed baseline endpoint accuracy. Mirror-image aftereffects occurred when rotation stopped. These findings demonstrate that manual control is disrupted by transient Coriolis force perturbations and that adaptation can occur even in the absence of visual feedback. An increase, even a small one, in background force level above normal gravity does not affect the size of the reaching errors induced by Coriolis forces nor does it affect the rate of reacquiring straight reaching paths; however, it does hinder restoration of reaching accuracy.

A review on natural background radiation

PubMed Central

Shahbazi-Gahrouei, Daryoush; Gholami, Mehrdad; Setayandeh, Samaneh

2013-01-01

The world is naturally radioactive and approximately 82% of human-absorbed radiation doses, which are out of control, arise from natural sources such as cosmic, terrestrial, and exposure from inhalation or intake radiation sources. In recent years, several international studies have been carried out, which have reported different values regarding the effect of background radiation on human health. Gamma radiation emitted from natural sources (background radiation) is largely due to primordial radionuclides, mainly 232Th and 238U series, and their decay products, as well as 40K, which exist at trace levels in the earth's crust. Their concentrations in soil, sands, and rocks depend on the local geology of each region in the world. Naturally occurring radioactive materials generally contain terrestrial-origin radionuclides, left over since the creation of the earth. In addition, the existence of some springs and quarries increases the dose rate of background radiation in some regions that are known as high level background radiation regions. The type of building materials used in houses can also affect the dose rate of background radiations. The present review article was carried out to consider all of the natural radiations, including cosmic, terrestrial, and food radiation. PMID:24223380

Measured Radiation and Background Levels During Transmission of Megawatt Electron Beams Through Millimeter Apertures

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

Alarcon, Ricardo; Balascuta, S.; Benson, Stephen V.

2013-11-01

We report measurements of photon and neutron radiation levels observed while transmitting a 0.43 MW electron beam through millimeter-sized apertures and during beam-off, but accelerating gradient RF-on, operation. These measurements were conducted at the Free-Electron Laser (FEL) facility of the Jefferson National Accelerator Laboratory (JLab) using a 100 MeV electron beam from an energy-recovery linear accelerator. The beam was directed successively through 6 mm, 4 mm, and 2 mm diameter apertures of length 127 mm in aluminum at a maximum current of 4.3 mA (430 kW beam power). This study was conducted to characterize radiation levels for experiments that needmore » to operate in this environment, such as the proposed DarkLight Experiment. We find that sustained transmission of a 430 kW continuous-wave (CW) beam through a 2 mm aperture is feasible with manageable beam-related backgrounds. We also find that during beam-off, RF-on operation, multipactoring inside the niobium cavities of the accelerator cryomodules is the primary source of ambient radiation when the machine is tuned for 130 MeV operation.« less

Air Pollution and Preterm Birth in the U.S. State of Georgia (2002–2006): Associations with Concentrations of 11 Ambient Air Pollutants Estimated by Combining Community Multiscale Air Quality Model (CMAQ) Simulations with Stationary Monitor Measurements

PubMed Central

Hao, Hua; Chang, Howard H.; Holmes, Heather A.; Mulholland, James A.; Klein, Mitch; Darrow, Lyndsey A.; Strickland, Matthew J.

2015-01-01

Background: Previous epidemiologic studies suggest associations between preterm birth and ambient air pollution. Objective: We investigated associations between 11 ambient air pollutants, estimated by combining Community Multiscale Air Quality model (CMAQ) simulations with measurements from stationary monitors, and risk of preterm birth (< 37 weeks of gestation) in the U.S. state of Georgia. Methods: Birth records for singleton births ≥ 27 weeks of gestation with complete covariate information and estimated dates of conception between 1 January 2002 and 28 February 2006 were obtained from the Office of Health Indicators for Planning, Georgia Department of Public Health (n = 511,658 births). Daily pollutant concentrations at 12-km resolution were estimated for 11 ambient air pollutants. We used logistic regression with county-level fixed effects to estimate associations between preterm birth and average pollutant concentrations during the first and second trimester. Discrete-time survival models were used to estimate third-trimester and total pregnancy associations. Effect modification was investigated by maternal education, race, census tract poverty level, and county-level urbanicity. Results: Trimester-specific and total pregnancy associations (p < 0.05) were observed for several pollutants. All the traffic-related pollutants (carbon monoxide, nitrogen dioxide, PM2.5 elemental carbon) were associated with preterm birth [e.g., odds ratios for interquartile range increases in carbon monoxide during the first, second, and third trimesters and total pregnancy were 1.005 (95% CI: 1.001, 1.009), 1.007 (95% CI: 1.002, 1.011), 1.010 (95% CI: 1.006, 1.014), and 1.011 (95% CI: 1.006, 1.017)]. Associations tended to be higher for mothers with low educational attainment and African American mothers. Conclusion: Several ambient air pollutants were associated with preterm birth; associations were observed in all exposure windows. Citation: Hao H, Chang HH, Holmes HA

Flying-qualities criteria for wings-level-turn maneuvering during an air-to-ground weapon delivery task

NASA Technical Reports Server (NTRS)

Sammonds, R. I.; Bunnell, J. W., Jr.

1980-01-01

A moving-base simulator experiment conducted at Ames Research Center demonstrated that a wings-level-turn control mode improved flying qualities for air-to-ground weapons delivery compared with those of a conventional aircraft. Evaluations of criteria for dynamic response for this system have shown that pilot ratings correlate well on the basis of equivalent time constant of the initial response. Ranges of this time constant, as well as digital-system transport delays and lateral-acceleration control authorities that encompassed Level I through Level III handling qualities, were determined.

Broadband spectra of seismic survey air-gun emissions, with reference to dolphin auditory thresholds.

PubMed

Goold, J C; Fish, P J

1998-04-01

Acoustic emissions from a 2120 cubic in air-gun array were recorded through a towed hydrophone assembly during an oil industry 2-D seismic survey off the West Wales Coast of the British Isles. Recorded seismic pulses were sampled, calibrated, and analyzed post-survey to investigate power levels of the pulses in the band 200 Hz-22 kHz at 750-m, 1-km, 2.2-km, and 8-km range from source. At 750-m range from source, seismic pulse power at the 200-Hz end of the spectrum was 140 dB re: 1 microPa2/Hz, and at the 20-kHz end of the spectrum seismic pulse power was 90 dB re: 1 microPa2/Hz. Although the background noise levels of the seismic recordings were far in excess of ambient, due to the proximity of engine, propeller, and flow sources of the ship towing the hydrophone, seismic power dominated the entire recorded bandwidth of 200 Hz-22 kHz at ranges of up to 2 km from the air-gun source. Even at 8-km range seismic power was still clearly in excess of the high background noise levels up to 8 kHz. Acoustic observations of common dolphins during preceding seismic surveys suggest that these animals avoided the immediate vicinity of the air-gun array while firing was in progress, i.e., localized disturbance occurred during seismic surveying. Although a general pattern of localized disturbance is suggested, one specific observation revealed that common dolphins were able to tolerate the seismic pulses at 1-km range from the air-gun array. Given the high broadband seismic pulse power levels across the entire recorded bandwidth, and known auditory thresholds for several dolphin species, we consider such seismic emissions to be clearly audible to dolphins across a bandwidth of tens on kilohertz, and at least out to 8-km range.

China's air pollution reduction efforts may result in an increase in surface ozone levels in highly polluted areas.

PubMed

Anger, Annela; Dessens, Olivier; Xi, Fengming; Barker, Terry; Wu, Rui

2016-03-01

China, as a fast growing fossil-fuel-based economy, experiences increasing levels of air pollution. To tackle air pollution, China has taken the first steps by setting emission-reduction targets for nitrogen oxides (NO x ) and sulphur dioxide (SO2) in the 11th and 12th Five Year Plans. This paper uses two models-the Energy-Environment-Economy Model at the Global level (E3MG) and the global Chemistry Transport Model pTOMCAT-to test the effects of these policies. If the policy targets are met, then the maximum values of 32 % and 45 % reductions below 'business as usual' in the monthly mean NO x and SO2 concentrations, respectively, will be achieved in 2015. However, a decrease in NO x concentrations in some highly polluted areas of East, North-East and South-East China can lead to up to a 10% increase in the monthly mean concentrations in surface ozone in 2015. Our study demonstrates an urgent need for the more detailed analysis of the impacts and designs of air pollution reduction guidelines for China.

Mitigation of building-related polychlorinated biphenyls in indoor air of a school

PubMed Central

2012-01-01

Background Sealants and other building materials sold in the U.S. from 1958 - 1971 were commonly manufactured with polychlorinated biphenyls (PCBs) at percent quantities by weight. Volatilization of PCBs from construction materials has been reported to produce PCB levels in indoor air that exceed health protective guideline values. The discovery of PCBs in indoor air of schools can produce numerous complications including disruption of normal operations and potential risks to health. Understanding the dynamics of building-related PCBs in indoor air is needed to identify effective strategies for managing potential exposures and risks. This paper reports on the efficacy of selected engineering controls implemented to mitigate concentrations of PCBs in indoor air. Methods Three interventions (ventilation, contact encapsulation, and physical barriers) were evaluated in an elementary school with PCB-containing caulk and elevated PCB concentrations in indoor air. Fluorescent light ballasts did not contain PCBs. Following implementation of the final intervention, measurements obtained over 14 months were used to assess the efficacy of the mitigation methods over time as well as temporal variability of PCBs in indoor air. Results Controlling for air exchange rates and temperature, the interventions produced statistically significant (p < 0.05) reductions in concentrations of PCBs in indoor air of the school. The mitigation measures remained effective over the course of the entire follow-up period. After all interventions were implemented, PCB levels in indoor air were associated with indoor temperature. In a "broken-stick" regression model with a node at 20°C, temperature explained 79% of the variability of indoor PCB concentrations over time (p < 0.001). Conclusions Increasing outdoor air ventilation, encapsulating caulk, and constructing a physical barrier over the encapsulated material were shown to be effective at reducing exposure concentrations of PCBs in indoor air

Meta-Prediction of the Effect of Methylenetetrahydrofolate Reductase Polymorphisms and Air Pollution on Alzheimer’s Disease Risk

PubMed Central

Wu, Suh-Mian; Chen, Zhao-Feng; Young, Lufei; Shiao, S. Pamela K.

2017-01-01

Background: Alzheimer’s disease (AD) is a significant public health issue. AD has been linked with methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism, but the findings have been inconsistent. The purpose of this meta-predictive analysis is to examine the associations between MTHFR polymorphisms and epigenetic factors, including air pollution, with AD risk using big data analytics approaches. Methods and Results: Forty-three studies (44 groups) were identified by searching various databases. MTHFR C677T TT and CT genotypes had significant associations with AD risk in all racial populations (RR = 1.13, p = 0.0047; and RR = 1.12, p < 0.0001 respectively). Meta-predictive analysis showed significant increases of percentages of MTHFR C677T polymorphism with increased air pollution levels in both AD case group and control group (p = 0.0021–0.0457); with higher percentages of TT and CT genotypes in the AD case group than that in the control group with increased air pollution levels. Conclusions: The impact of MTHFR C677T polymorphism on susceptibility to AD was modified by level of air pollution. Future studies are needed to further examine the effects of gene-environment interactions including air pollution on AD risk for world populations. PMID:28085050

Air Pollution and Stroke

PubMed Central

Lee, Kuan Ken; Miller, Mark R.; Shah, Anoop S. V.

2018-01-01

The adverse health effects of air pollution have long been recognised; however, there is less awareness that the majority of the morbidity and mortality caused by air pollution is due to its effects on the cardiovascular system. Evidence from epidemiological studies have demonstrated a strong association between air pollution and cardiovascular diseases including stroke. Although the relative risk is small at an individual level, the ubiquitous nature of exposure to air pollution means that the absolute risk at a population level is on a par with “traditional” risk factors for cardiovascular disease. Of particular concern are findings that the strength of this association is stronger in low and middle income countries where air pollution is projected to rise as a result of rapid industrialisation. The underlying biological mechanisms through which air pollutants exert their effect on the vasculature are still an area of intense discussion. A greater understanding of the effect size and mechanisms is necessary to develop effective strategies at individual and policy levels to mitigate the adverse cardiovascular effects of air pollution. PMID:29402072

Air Pollution and Stroke.

PubMed

Lee, Kuan Ken; Miller, Mark R; Shah, Anoop S V

2018-01-01

The adverse health effects of air pollution have long been recognised; however, there is less awareness that the majority of the morbidity and mortality caused by air pollution is due to its effects on the cardiovascular system. Evidence from epidemiological studies have demonstrated a strong association between air pollution and cardiovascular diseases including stroke. Although the relative risk is small at an individual level, the ubiquitous nature of exposure to air pollution means that the absolute risk at a population level is on a par with "traditional" risk factors for cardiovascular disease. Of particular concern are findings that the strength of this association is stronger in low and middle income countries where air pollution is projected to rise as a result of rapid industrialisation. The underlying biological mechanisms through which air pollutants exert their effect on the vasculature are still an area of intense discussion. A greater understanding of the effect size and mechanisms is necessary to develop effective strategies at individual and policy levels to mitigate the adverse cardiovascular effects of air pollution.

Evaluation of air sparging and vadose zone aeration for remediation of iron and manganese-impacted groundwater at a closed municipal landfill.

PubMed

Pleasant, Saraya; O'Donnell, Amanda; Powell, Jon; Jain, Pradeep; Townsend, Timothy

2014-07-01

High concentrations of iron (Fe(II)) and manganese (Mn(II)) reductively dissolved from soil minerals have been detected in groundwater monitoring wells near many municipal solid waste landfills. Air sparging and vadose zone aeration (VZA) were evaluated as remedial approaches at a closed, unlined municipal solid waste landfill in Florida, USA. The goal of aeration was to oxidize Fe and Mn to their respective immobile forms. VZA and shallow air sparging using a partially submerged well screen were employed with limited success (Phase 1); decreases in dissolved iron were observed in three of nine monitoring wells during shallow air sparging and in two of 17 wells at VZA locations. During Phase 2, where deeper air sparging was employed, dissolved iron levels decreased in a significantly greater number of monitoring wells surrounding injection points, however no radial pattern was observed. Additionally, in wells affected positively by air sparging (mean total iron (FeTOT) <4.2mg/L, after commencement of air sparging), rising manganese concentrations were observed, indicating that the redox potential of the groundwater moved from an iron-reducing to a manganese-reducing environment. The mean FeTOT concentration observed in affected monitoring wells throughout the study was 1.40 mg/L compared to a background of 15.38 mg/L, while the mean Mn concentration was 0.60 mg/L compared to a background level of 0.27 mg/L. Reference wells located beyond the influence of air sparging areas showed little variation in FeTOT and Mn, indicating the observed effects were the result of air injection activities at study locations and not a natural phenomenon. Air sparging was found effective in intercepting plumes of dissolved Fe surrounding municipal landfills, but the effect on dissolved Mn was contrary to the desired outcome of decreased Mn groundwater concentrations. Copyright © 2014 Elsevier B.V. All rights reserved.

Mixing Heights and Three-Dimensional Ozone Structure Observed by Airborne Lidar During the 2006 Texas Air Quality Study

NASA Astrophysics Data System (ADS)

Hardesty, R. M.; Senff, C. J.; Alvarez, R. J.; Banta, R. M.; Sandberg, S. P.; Weickmann, A. M.; Darby, L. S.

2007-12-01

A new all solid state ozone lidar was deployed on a NOAA Twin Otter to study boundary layer ozone and aerosol, mostly around Houston, during the 2006 Texas Air Quality Study. The new instrument transmits high pulse-rate, low pulse-energy light at 3 wavelengths in the ultraviolet to obtain ozone profiles with 500 m horizontal resolution and 90 m vertical resolution. During the Texas field study, 20 research flights resulted in nearly 70 hours of ozone measurements during the period from August 1 to September 15. Science objectives included characterization of background ozone levels over rural areas near Houston and Dallas and variability and structure of the boundary layer over different surface types, including urban, wooded, and agricultural land surface areas as well as over Galveston Bay and the Gulf of Mexico. A histogram of all boundary layer ozone concentration measurements showed a bimodal distribution with modes at 45 ppb and 70 ppb. The lower mode correlated with southerly flow, when relatively clean air was transported onshore into the Houston area. Segmenting the observations during southerly flow by region, including the Gulf of Mexico, land within about 55 km from the coast, and further inland indicated that background levels increased by about 10 ppb as air was transported onshore. During the latter part of the experiment, as more pollution was imported into the Houston region, background levels rose to nearly 80 ppb in regions N of Houston. Two flights aimed at observing import of ozone into Texas from the east showed that ozone concentrations increased and boundary layer depths deepened upwind of Houston between September 4 and September 8. Background levels rose by more than 10 ppb over this period. In addition to ozone measurements, we also estimated boundary layer height based on maximum gradient in observed backscatter. The technique worked well when the layer topped by the strongest gradient extends down to the surface. Investigation of the

Socioeconomic and urban-rural differentials in exposure to air pollution and mortality burden in England.

PubMed

Milojevic, Ai; Niedzwiedz, Claire L; Pearce, Jamie; Milner, James; MacKenzie, Ian A; Doherty, Ruth M; Wilkinson, Paul

2017-10-06

Socioeconomically disadvantaged populations often have higher exposures to particulate air pollution, which can be expected to contribute to differentials in life expectancy. We examined socioeconomic differentials in exposure and air pollution-related mortality relating to larger scale (5 km resolution) variations in background concentrations of selected pollutants across England. Ozone and particulate matter (sub-divided into PM 10 , PM 2.5 , PM 2.5-10 , primary, nitrate and sulphate PM 2.5 ) were simulated at 5 km horizontal resolution using an atmospheric chemistry transport model (EMEP4UK). Annual mean concentrations of these pollutants were assigned to all 1,202,578 residential postcodes in England, which were classified by urban-rural status and socioeconomic deprivation based on the income and employment domains of the 2010 English Index of Multiple Deprivation for the Lower-level Super Output Area of residence. We used life table methods to estimate PM 2.5 -attributable life years (LYs) lost in both relative and absolute terms. Concentrations of the most particulate fractions, but not of nitrate PM 2.5 or ozone, were modestly higher in areas of greater socioeconomic deprivation. Relationships between pollution level and socioeconomic deprivation were non-linear and varied by urban-rural status. The pattern of PM 2.5 concentrations made only a small contribution to the steep socioeconomic gradient in LYs lost due to PM 2.5 per 10 3 population, which primarily was driven by the steep socioeconomic gradient in underlying mortality rates. In rural areas, the absolute burden of air pollution-related LYs lost was lowest in the most deprived deciles. Air pollution shows modest socioeconomic patterning at 5 km resolution in England, but absolute attributable mortality burdens are strongly related to area-level deprivation because of underlying mortality rates. Measures that cause a general reduction in background concentrations of air pollution may modestly

Seasonal changes in background levels of deuterium and oxygen-18 prove water drinking by harp seals, which affects the use of the doubly labelled water method.

PubMed

Nordøy, Erling S; Lager, Anne R; Schots, Pauke C

2017-12-01

The aim of this study was to monitor seasonal changes in stable isotopes of pool freshwater and harp seal ( Phoca groenlandica ) body water, and to study whether these potential seasonal changes might bias results obtained using the doubly labelled water (DLW) method when measuring energy expenditure in animals with access to freshwater. Seasonal changes in the background levels of deuterium and oxygen-18 in the body water of four captive harp seals and in the freshwater pool in which they were kept were measured over a time period of 1 year. The seals were offered daily amounts of capelin and kept under a seasonal photoperiod of 69°N. Large seasonal variations of deuterium and oxygen-18 in the pool water were measured, and the isotope abundance in the body water showed similar seasonal changes to the pool water. This shows that the seals were continuously equilibrating with the surrounding water as a result of significant daily water drinking. Variations in background levels of deuterium and oxygen-18 in freshwater sources may be due to seasonal changes in physical processes such as precipitation and evaporation that cause fractionation of isotopes. Rapid and abrupt changes in the background levels of deuterium and oxygen-18 may complicate calculation of energy expenditure by use of the DLW method. It is therefore strongly recommended that analysis of seasonal changes in background levels of isotopes is performed before the DLW method is applied on (free-ranging) animals, and to use a control group in order to correct for changes in background levels. © 2017. Published by The Company of Biologists Ltd.

Heated air humidification versus cold air nebulization in newly tracheostomized patients

PubMed Central

Händel, Alexander; Wenzel, Angela; Kramer, Benedikt; Aderhold, Christoph; Hörmann, Karl; Stuck, Boris A.; Sommer, J. Ulrich

2017-01-01

Abstract Background After tracheostomy, the airway lacks an essential mechanism for warming and humidifying the inspired air with the consequent functional impairment and discomfort. The purpose of this study was to compare airway hydration with cold‐air nebulization versus heated high‐flow humidification on medical interventions and tracheal ciliary beat frequency (CBF). Methods Newly tracheostomized patients (n = 20) were treated either with cold‐air nebulization or heated humidification. The number of required tracheal suctioning procedures to clean the trachea and tracheal CBF were assessed. Results The number of required suctions per day was significantly lower in the heated humidification group with medians 3 versus 5 times per day. Mean CBF was significantly higher in the heated humidification group (6.36 ± 1.49 Hz) compared to the cold‐air nebulization group (3.99 ± 1.39 Hz). Conclusion The data suggest that heated humidification enhanced mucociliary transport leading to a reduced number of required suctioning procedures in the trachea, which may improve postoperative patient care. PMID:28990261

Essential air service : changes in passenger traffic, subsidy levels, and air carrier costs

DOT National Transportation Integrated Search

2000-05-25

Over two decades have passed since the Congress phased out the federal government's control over airfares and service. Concerned that air service to some small communities would suffer in a deregulated environment, the Congress established the Essent...

Surface ozone and carbon monoxide levels observed at Oki, Japan: regional air pollution trends in East Asia.

PubMed

Sikder, Helena Akhter; Suthawaree, Jeeranut; Kato, Shungo; Kajii, Yoshizumi

2011-03-01

Simultaneous ground-based measurements of ozone and carbon monoxide were performed at Oki, Japan, from January 2001 to September 2002 in order to investigate the O(3) and CO characteristics and their distributions. The observations revealed that O(3) and CO concentrations were maximum in springtime and minimum in the summer. The monthly averaged concentrations of O(3) and CO were 60 and 234 ppb in spring and 23 and 106 ppb in summer, respectively. Based on direction, 5-day isentropic backward trajectory analysis was carried out to determine the transport path of air masses, preceding their arrival at Oki. Comparison between classified results from present work and results from the year 1994-1996 was carried out. The O(3) and CO concentration results of classified air masses in our analysis show similar concentration trends to previous findings; highest in the WNW/W, lowest in N/NE and medium levels in NW. Moreover, O(3) levels are higher and CO levels are lower in the present study in all categories. Copyright © 2010 Elsevier Ltd. All rights reserved.

Air ions and mood outcomes: a review and meta-analysis

PubMed Central

2013-01-01

Background Psychological effects of air ions have been reported for more than 80 years in the media and scientific literature. This study summarizes a qualitative literature review and quantitative meta-analysis, where applicable, that examines the potential effects of exposure to negative and positive air ions on psychological measures of mood and emotional state. Methods A structured literature review was conducted to identify human experimental studies published through August, 2012. Thirty-three studies (1957–2012) evaluating the effects of air ionization on depression, anxiety, mood states, and subjective feelings of mental well-being in humans were included. Five studies on negative ionization and depression (measured using a structured interview guide) were evaluated by level of exposure intensity (high vs. low) using meta-analysis. Results Consistent ionization effects were not observed for anxiety, mood, relaxation/sleep, and personal comfort. In contrast, meta-analysis results showed that negative ionization, overall, was significantly associated with lower depression ratings, with a stronger association observed at high levels of negative ion exposure (mean summary effect and 95% confidence interval (CI) following high- and low-density exposure: 14.28 (95% CI: 12.93-15.62) and 7.23 (95% CI: 2.62-11.83), respectively). The response to high-density ionization was observed in patients with seasonal or chronic depression, but an effect of low-density ionization was observed only in patients with seasonal depression. However, no relationship between the duration or frequency of ionization treatment on depression ratings was evident. Conclusions No consistent influence of positive or negative air ionization on anxiety, mood, relaxation, sleep, and personal comfort measures was observed. Negative air ionization was associated with lower depression scores particularly at the highest exposure level. Future research is needed to evaluate the biological

Outdoor air pollutants and patient health.

PubMed

Laumbach, Robert J

2010-01-15

Almost 160 million persons live in areas of the United States that exceed federal health-based air pollution standards. The two air pollutants that most commonly exceed standards are ozone and particulate matter. Ozone and particulate matter can harm anyone if levels are sufficiently elevated, but health risk from air pollution is greatest among vulnerable populations. Both ozone and particulate matter can cause pulmonary inflammation, decreased lung function, and exacerbation of asthma and chronic obstructive pulmonary disease. Particulate matter is also strongly associated with increased cardiovascular morbidity and mortality. Children, older adults, and other vulnerable persons may be sensitive to lower levels of air pollution. Persons who are aware of local air pollution levels, reported daily by the U.S. Environmental Protection Agency as the Air Quality Index, can take action to reduce exposure. These actions include simple measures to limit exertion and time spent outdoors when air pollution levels are highest, and to reduce the infiltration of outdoor air pollutants into indoor spaces.

Contrast in air pollution components between major streets and background locations: Particulate matter mass, black carbon, elemental composition, nitrogen oxide and ultrafine particle number

NASA Astrophysics Data System (ADS)

Boogaard, Hanna; Kos, Gerard P. A.; Weijers, Ernie P.; Janssen, Nicole A. H.; Fischer, Paul H.; van der Zee, Saskia C.; de Hartog, Jeroen J.; Hoek, Gerard

2011-01-01

Policies to reduce outdoor air pollution concentrations are often assessed on the basis of the regulated pollutants. Whether these are the most appropriate components to assess the potential health benefits is questionable, as other health-relevant pollutants may be more strongly related to traffic. The aim of this study is to compare the contrast in concentration between major roads and (sub)urban background for a large range of pollutants and to analyze the magnitude of the measured difference in the street - background for major streets with different street configurations. Measurements of PM 10, PM 2.5, particle number concentrations (PNC), black carbon (BC), elemental composition of PM 10 and PM 2.5 and NO x were conducted simultaneously in eight major streets and nine (sub)urban background locations in the Netherlands. Measurements were done six times for a week during a six month period in 2008. High contrasts between busy streets and background locations in the same city were found for chromium, copper and iron (factor 2-3). These elements were especially present in the coarse fraction of PM. In addition, high contrasts were found for BC and NO x (factor 1.8), typically indicators of direct combustion emissions. The contrast for PNC was similar to BC. NO 2 contrast was lower (factor 1.5). The largest contrast was found for two street canyons and two streets with buildings at one side of the street only. The contrast between busy streets and urban background in NO 2 was less than the contrast found for BC, PNC and elements indicative of non-exhaust emissions, adding evidence that NO 2 is not representing (current) traffic well. The study supports a substantial role for non-exhaust emissions including brake- and tyre wear and road dust in addition to direct combustion emissions. Significant underestimation of disease burden may occur when relying too much on the regulated components.

A real time sorbent based air monitoring system for determining low level airborne exposure levels to Lewisite

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

Lattin, F.G.; Paul, D.G.; Jakubowski, E.M.

1994-12-31

The Real Time Analytical Platform (RTAP) is designed to provide mobile, real-time monitoring support to ensure protection of worker safety in areas where military unique compounds are used and stored, and at disposal sites. Quantitative analysis of low-level vapor concentrations in air is accomplished through sorbent-based collection with subsequent thermal desorption into a gas chromatograph (GC) equipped with a variety of detectors. The monitoring system is characterized by its sensitivity (ability to measure at low concentrations), selectivity (ability to filter out interferences), dynamic range and linearity, real time mode (versus methods requiring extensive sample preparation procedures), and ability to interfacemore » with complimentary GC detectors. This presentation describes an RTAP analytical method for analyzing lewisite, an arsenical compound, that consists of a GC screening technique with an Electron Capture Detector (ECD), and a confirmation technique using an Atomic Emission Detector (AED). Included in the presentation is a description of quality assurance objectives in the monitoring system, and an assessment of method accuracy, precision and detection levels.« less

Indoor air quality in Portuguese schools: levels and sources of pollutants.

PubMed

Madureira, J; Paciência, I; Pereira, C; Teixeira, J P; Fernandes, E de O

2016-08-01

Indoor air quality (IAQ) parameters in 73 primary classrooms in Porto were examined for the purpose of assessing levels of volatile organic compounds (VOCs), aldehydes, particulate matter, ventilation rates and bioaerosols within and between schools, and potential sources. Levels of VOCs, aldehydes, PM2.5 , PM10 , bacteria and fungi, carbon dioxide (CO2 ), carbon monoxide, temperature and relative humidity were measured indoors and outdoors and a walkthrough survey was performed concurrently. Ventilation rates were derived from CO2 and occupancy data. Concentrations of CO2 exceeding 1000 ppm were often encountered, indicating poor ventilation. Most VOCs had low concentrations (median of individual species <5 μg/m(3) ) and were below the respective WHO guidelines. Concentrations of particulate matter and culturable bacteria were frequently higher than guidelines/reference values. The variability of VOCs, aldehydes, bioaerosol concentrations, and CO2 levels between schools exceeded the variability within schools. These findings indicate that IAQ problems may persist in classrooms where pollutant sources exist and classrooms are poorly ventilated; source control strategies (related to building location, occupant behavior, maintenance/cleaning activities) are deemed to be the most reliable for the prevention of adverse health consequences in children in schools. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

C5-C12 volatile organic compounds at roadside, residential, and background locations in Ankara, Turkey: temporal and spatial variations and sources.

PubMed

Kuntasal, Oznur Oğuz; Kilavuz, Seda Aslan; Karman, Deniz; Wang, Daniel; Tuncel, Gürdal

2013-10-01

Concentrations of 91 volatile organic compounds (VOCs) ranging from C5 to C12 were measured at three sites in Ankara, the capital of Turkey, in the summer of 2003 and winter of 2004. Samples were collected at roadside, residential and background stations at consecutive 4-hr intervals over a 24-hr period for six weeks in each season. Air samples were collected onto cartridges packed with Tenax TA and Carbopack B resins and analyzed by thermal desorption, followed by gas chromatography coupled to a mass selective detector (GC/MSD). Time resolved data provided information on ambient levels, temporal and spatial variations and sources of VOCs in Ankara. Toluene is the most abundant compound at all sites with and average concentration of 13.1 ?g m(-3). The mean concentrations of benzene are 12.6, 5.2, and 2.4 ?g m(-3) during winter at roadside, residential and background stations, respectively. Diurnal variation in the data together with toluene to benzene concentration ratio (T:B) that is close to 2.0 indicated the influence of traffic related emissions at residential and roadside stations during winter season. Higher T:B ratio observed at residential and background stations during summer period and correlation analysis indicated additional VOC sources. Temporal variations and low m,p-xylene to ethylbenzene ratio (mpX:E) indicated that transported air mass is the major VOC source influencing VOC concentrations measured at the background station.

Control of asthma triggers in indoor air with air cleaners: a modeling analysis.

PubMed

Myatt, Theodore A; Minegishi, Taeko; Allen, Joseph G; Macintosh, David L

2008-08-06

Reducing exposure to environmental agents indoors shown to increase asthma symptoms or lead to asthma exacerbations is an important component of a strategy to manage asthma for individuals. Numerous investigations have demonstrated that portable air cleaning devices can reduce concentrations of asthma triggers in indoor air; however, their benefits for breathing problems have not always been reproducible. The potential exposure benefits of whole house high efficiency in-duct air cleaners for sensitive subpopulations have yet to be evaluated. We used an indoor air quality modeling system (CONTAM) developed by NIST to examine peak and time-integrated concentrations of common asthma triggers present in indoor air over a year as a function of natural ventilation, portable air cleaners, and forced air ventilation equipped with conventional and high efficiency filtration systems. Emission rates for asthma triggers were based on experimental studies published in the scientific literature. Forced air systems with high efficiency filtration were found to provide the best control of asthma triggers: 30-55% lower cat allergen levels, 90-99% lower risk of respiratory infection through the inhalation route of exposure, 90-98% lower environmental tobacco smoke (ETS) levels, and 50-75% lower fungal spore levels than the other ventilation/filtration systems considered. These results indicate that the use of high efficiency in-duct air cleaners provide an effective means of controlling allergen levels not only in a single room, like a portable air cleaner, but the whole house. These findings are useful for evaluating potential benefits of high efficiency in-duct filtration systems for controlling exposure to asthma triggers indoors and for the design of trials of environmental interventions intended to evaluate their utility in practice.

LINKING PUBLIC HEALTH AND AIR QUALITY DATA FOR ACCOUNTABILITY

EPA Science Inventory

Program Area: Environmental Health

Topic Area: Linking Public Health Data into Action

Title of Presentation: Linking Public Health and Air Quality Data for Accountability

Background and Significance

Tracking environmental exposures to air pollutan...

AirMSPI Level 1B2 V005 New Data for NASA’s SEAC4RS Campaign

Atmospheric Science Data Center

2018-05-07

AirMSPI Level 1B2 V005 New Data for NASA’s SEAC4RS Campaign Wednesday, February 14, 2018 ... 865, and 935 nm. The data products include radiance, time, solar zenith, solar azimuth, view zenith, and view azimuth for all spectral ...

Exposure to Traffic-Related Air Pollution and Serum Inflammatory Cytokines in Children

PubMed Central

Merid, Simon Kebede; Gref, Anna; Gajulapuri, Ashwini; Lemonnier, Nathanaël; Ballereau, Stéphane; Gigante, Bruna; Kere, Juha; Auffray, Charles; Melén, Erik; Pershagen, Göran

2017-01-01

Background: Long-term exposure to ambient air pollution can lead to adverse health effects in children; however, underlying biological mechanisms are not fully understood. Objectives: We evaluated the effect of air pollution exposure during different time periods on mRNA expression as well as circulating levels of inflammatory cytokines in children. Methods: We measured a panel of 10 inflammatory markers in peripheral blood samples from 670 8-y-old children in the Barn/Child, Allergy, Milieu, Stockholm, Epidemiology (BAMSE) birth cohort. Outdoor concentrations of nitrogen dioxide (NO2) and particulate matter (PM) with aerodynamic diameter <10μm (PM10) from road traffic were estimated for residential, daycare, and school addresses using dispersion modeling. Time-weighted average exposures during infancy and at biosampling were linked to serum cytokine levels using linear regression analysis. Furthermore, gene expression data from 16-year-olds in BAMSE (n=238) were used to evaluate links between air pollution exposure and expression of genes coding for the studied inflammatory markers. Results: A 10 μg/m3 increase of NO2 exposure during infancy was associated with a 13.6% (95% confidence interval (CI): 0.8; 28.1%) increase in interleukin-6 (IL-6) levels, as well as with a 27.8% (95% CI: 4.6, 56.2%) increase in IL-10 levels, the latter limited to children with asthma. However, no clear associations were observed for current exposure. Results were similar using PM10, which showed a high correlation with NO2. The functional analysis identified several differentially expressed genes in response to air pollution exposure during infancy, including IL10, IL13, and TNF. Conclusion: Our results indicate alterations in systemic inflammatory markers in 8-y-old children in relation to early-life exposure to traffic-related air pollution. https://doi.org/10.1289/EHP460 PMID:28669936

The influence of declining air lead levels on blood lead-air lead slope factors in children.

PubMed

Richmond-Bryant, Jennifer; Meng, Qingyu; Davis, Allen; Cohen, Jonathan; Lu, Shou-En; Svendsgaard, David; Brown, James S; Tuttle, Lauren; Hubbard, Heidi; Rice, Joann; Kirrane, Ellen; Vinikoor-Imler, Lisa C; Kotchmar, Dennis; Hines, Erin P; Ross, Mary

2014-07-01

It is difficult to discern the proportion of blood lead (PbB) attributable to ambient air lead (PbA), given the multitude of lead (Pb) sources and pathways of exposure. The PbB-PbA relationship has previously been evaluated across populations. This relationship was a central consideration in the 2008 review of the Pb national ambient air quality standards. The objectives of this study were to evaluate the relationship between PbB and PbA concentrations among children nationwide for recent years and to compare the relationship with those obtained from other studies in the literature. We merged participant-level data for PbB from the National Health and Nutrition Examination Survey (NHANES) III (1988-1994) and NHANES 9908 (1999-2008) with PbA data from the U.S. Environmental Protection Agency. We applied mixed-effects models, and we computed slope factor, d[PbB]/d[PbA] or the change in PbB per unit change in PbA, from the model results to assess the relationship between PbB and PbA. Comparing the NHANES regression results with those from the literature shows that slope factor increased with decreasing PbA among children 0-11 years of age. These findings suggest that a larger relative public health benefit may be derived among children from decreases in PbA at low PbA exposures. Simultaneous declines in Pb from other sources, changes in PbA sampling uncertainties over time largely related to changes in the size distribution of Pb-bearing particulate matter, and limitations regarding sampling size and exposure error may contribute to the variability in slope factor observed across peer-reviewed studies.

Air Pollution Control Policies in China: A Retrospective and Prospects

PubMed Central

Jin, Yana; Andersson, Henrik; Zhang, Shiqiu

2016-01-01

With China’s significant role on pollution emissions and related health damage, deep and up-to-date understanding of China’s air pollution policies is of worldwide relevance. Based on scientific evidence for the evolution of air pollution and the institutional background of environmental governance in China, we examine the development of air pollution control policies from the 1980s and onwards. We show that: (1) The early policies, until 2005, were ineffective at reducing emissions; (2) During 2006–2012, new instruments which interact with political incentives were introduced in the 11th Five-Year Plan, and the national goal of reducing total sulfur dioxide (SO2) emissions by 10% was achieved. However, regional compound air pollution problems dominated by fine particulate matter (PM2.5) and ground level ozone (O3) emerged and worsened; (3) After the winter-long PM2.5 episode in eastern China in 2013, air pollution control policies have been experiencing significant changes on multiple fronts. In this work we analyze the different policy changes, the drivers of changes and key factors influencing the effectiveness of policies in these three stages. Lessons derived from the policy evolution have implications for future studies, as well as further reforming the management scheme towards air quality and health risk oriented directions. PMID:27941665

Developing Community-Level Policy and Practice to Reduce Traffic-Related Air Pollution Exposure

PubMed Central

Brugge, Doug; Patton, Allison P.; Bob, Alex; Reisner, Ellin; Lowe, Lydia; Bright, Oliver-John M.; Durant, John L.; Newman, Jim; Zamore, Wig

2016-01-01

The literature consistently shows associations of adverse cardiovascular and pulmonary outcomes with residential proximity to highways and major roadways. Air monitoring shows that traffic-related pollutants (TRAP) are elevated within 200–400 m of these roads. Community-level tactics for reducing exposure include the following: 1) HEPA filtration; 2) Appropriate air-intake locations; 3) Sound proofing, insulation and other features; 4) Land-use buffers; 5) Vegetation or wall barriers; 6) Street-side trees, hedges and vegetation; 7) Decking over highways; 8) Urban design including placement of buildings; 9) Garden and park locations; and 10) Active travel locations, including bicycling and walking paths. A multidisciplinary design charrette was held to test the feasibility of incorporating these tactics into near-highway housing and school developments that were in the planning stages. The resulting designs successfully utilized many of the protective tactics and also led to engagement with the designers and developers of the sites. There is a need to increase awareness of TRAP in terms of building design and urban planning. PMID:27413416

Assessment of neighbourhood-level socioeconomic status as a modifier of air pollution-asthma associations among children in Atlanta.

PubMed

O'Lenick, Cassandra R; Winquist, Andrea; Mulholland, James A; Friberg, Mariel D; Chang, Howard H; Kramer, Michael R; Darrow, Lyndsey A; Sarnat, Stefanie Ebelt

2017-02-01

A broad literature base provides evidence of association between air pollution and paediatric asthma. Socioeconomic status (SES) may modify these associations; however, previous studies have found inconsistent evidence regarding the role of SES. Effect modification of air pollution-paediatric asthma morbidity by multiple indicators of neighbourhood SES was examined in Atlanta, Georgia. Emergency department (ED) visit data were obtained for 5-18 years old with a diagnosis of asthma in 20-county Atlanta during 2002-2008. Daily ZIP Code Tabulation Area (ZCTA)-level concentrations of ozone, nitrogen dioxide, fine particulate matter and elemental carbon were estimated using ambient monitoring data and emissions-based chemical transport model simulations. Pollutant-asthma associations were estimated using a case-crossover approach, controlling for temporal trends and meteorology. Effect modification by ZCTA-level (neighbourhood) SES was examined via stratification. We observed stronger air pollution-paediatric asthma associations in 'deprivation areas' (eg, ≥20% of the ZCTA population living in poverty) compared with 'non-deprivation areas'. When stratifying analyses by quartiles of neighbourhood SES, ORs indicated stronger associations in the highest and lowest SES quartiles and weaker associations among the middle quartiles. Our results suggest that neighbourhood-level SES is a factor contributing vulnerability to air pollution-related paediatric asthma morbidity in Atlanta. Children living in low SES environments appear to be especially vulnerable given positive ORs and high underlying asthma ED rates. Inconsistent findings of effect modification among previous studies may be partially explained by choice of SES stratification criteria, and the use of multiplicative models combined with differing baseline risk across SES populations. 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/.

Spatial variation in environmental noise and air pollution in New York City.

PubMed

Kheirbek, Iyad; Ito, Kazuhiko; Neitzel, Richard; Kim, Jung; Johnson, Sarah; Ross, Zev; Eisl, Holger; Matte, Thomas

2014-06-01

Exposure to environmental noise from traffic is common in urban areas and has been linked to increased risks of adverse health effects including cardiovascular disease. Because traffic sources also produce air pollutants that increase the risk of cardiovascular morbidity, associations between traffic exposures and health outcomes may involve confounding and/or synergisms between air pollution and noise. While prior studies have characterized intraurban spatial variation in air pollution in New York City (NYC), limited data exists on the levels and spatial variation in noise levels. We measured 1-week equivalent continuous sound pressure levels (Leq) at 56 sites during the fall of 2012 across NYC locations with varying traffic intensity and building density that are routinely monitored for combustion-related air pollutants. We evaluated correlations among several noise metrics used to characterize noise exposures, including Leq during different time periods (night, day, weekday, weekend), Ldn (day-night noise), and measures of intermittent noise defined as the ratio of peak levels to median and background levels. We also examined correlations between sound pressure levels and co-located simultaneous measures of nitric oxide (NO), nitrogen dioxide (NO2), fine particulate matter (PM2.5), and black carbon (BC) as well as estimates of traffic and building density around the monitoring sites. Noise levels varied widely across the 56 monitoring sites; 1-week Leq varied by 21.6 dBA (range 59.1-80.7 dBA) with the highest levels observed during the weekday, daytime hours. Indices of average noise were well correlated with each other (r > 0.83), while indices of intermittent noise were not well correlated with average noise levels (r < 0.41). One-week Leq correlated well with NO, NO2, and EC levels (r = 0.61 to 0.68) and less so with PM2.5 levels (r = 0.45). We observed associations between 1-week noise levels and traffic intensity within 100 m of the monitoring sites (r = 0

Air Force KC-X Tanker Aircraft Program: Background and Issues for Congress

DTIC Science & Technology

2009-10-05

General ..................................................................................................................... 12 Best Value vs . Lowest...Druyan was a single “bad apple ” and that her actions did not negate the merits of leasing Boeing 767s for use as tankers. In February 2005, however...Force KC-X Tanker Aircraft Program: Background and Issues for Congress Congressional Research Service 17 Best Value vs . Lowest Cost The question of

Field controlled experiments on the physiological responses of maize (Zea mays L.) leaves to low-level air and soil mercury exposures.

PubMed

Niu, Zhenchuan; Zhang, Xiaoshan; Wang, Sen; Zeng, Ming; Wang, Zhangwei; Zhang, Yi; Ci, Zhijia

2014-01-01

Thousands of tons of mercury (Hg) are released from anthropogenic and natural sources to the atmosphere in a gaseous elemental form per year, yet little is known regarding the influence of airborne Hg on the physiological activities of plant leaves. In the present study, the effects of low-level air and soil Hg exposures on the gas exchange parameters of maize (Zea mays L.) leaves and their accumulation of Hg, proline, and malondialdehyde (MDA) were examined via field open-top chamber and Hg-enriched soil experiments, respectively. Low-level air Hg exposures (<50 ng m(-3)) had little effects on the gas exchange parameters of maize leaves during most of the daytime (p > 0.05). However, both the net photosynthesis rate and carboxylation efficiency of maize leaves exposed to 50 ng m(-3) air Hg were significantly lower than those exposed to 2 ng m(-3) air Hg in late morning (p < 0.05). Additionally, the Hg, proline, and MDA concentrations in maize leaves exposed to 20 and 50 ng m(-3) air Hg were significantly higher than those exposed to 2 ng m(-3) air Hg (p < 0.05). These results indicated that the increase in airborne Hg potentially damaged functional photosynthetic apparatus in plant leaves, inducing free proline accumulation and membrane lipid peroxidation. Due to minor translocation of soil Hg to the leaves, low-level soil Hg exposures (<1,000 ng g(-1)) had no significant influences on the gas exchange parameters, or the Hg, proline, and MDA concentrations in maize leaves (p > 0.05). Compared to soil Hg, airborne Hg easily caused physiological stress to plant leaves. The effects of increasing atmospheric Hg concentration on plant physiology should be of concern.

Estimates of ground level TSP, SO sub 2 and HCI for a municipal waste incinerator to be located at Tynes Bay - Bermuda

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

Kent Simmons, J.A.; Knap, A.H.

1991-04-01

The computer model Industrial Source Complex Short Term (ISCST) was used to study the stack emissions from a refuse incinerator proposed for the inland of Bermuda. The model predicts that the highest ground level pollutant concentrations will occur near Prospect, 800 m to 1,000 m due south of the stack. The authors installed a portable laboratory and instruments at Prospect to begin making air quality baseline measurements. By comparing the model's estimates of the incinerator contribution to the background levels measured at the site they predicted that stack emissions would not cause an increase in TSP or SO{sub 2}. Themore » incinerator will be a significant source of HCI to Bermuda air with ambient levels approaching air quality guidelines.« less

Background field removal using a region adaptive kernel for quantitative susceptibility mapping of human brain.

PubMed

Fang, Jinsheng; Bao, Lijun; Li, Xu; van Zijl, Peter C M; Chen, Zhong

2017-08-01

Background field removal is an important MR phase preprocessing step for quantitative susceptibility mapping (QSM). It separates the local field induced by tissue magnetic susceptibility sources from the background field generated by sources outside a region of interest, e.g. brain, such as air-tissue interface. In the vicinity of air-tissue boundary, e.g. skull and paranasal sinuses, where large susceptibility variations exist, present background field removal methods are usually insufficient and these regions often need to be excluded by brain mask erosion at the expense of losing information of local field and thus susceptibility measures in these regions. In this paper, we propose an extension to the variable-kernel sophisticated harmonic artifact reduction for phase data (V-SHARP) background field removal method using a region adaptive kernel (R-SHARP), in which a scalable spherical Gaussian kernel (SGK) is employed with its kernel radius and weights adjustable according to an energy "functional" reflecting the magnitude of field variation. Such an energy functional is defined in terms of a contour and two fitting functions incorporating regularization terms, from which a curve evolution model in level set formation is derived for energy minimization. We utilize it to detect regions of with a large field gradient caused by strong susceptibility variation. In such regions, the SGK will have a small radius and high weight at the sphere center in a manner adaptive to the voxel energy of the field perturbation. Using the proposed method, the background field generated from external sources can be effectively removed to get a more accurate estimation of the local field and thus of the QSM dipole inversion to map local tissue susceptibility sources. Numerical simulation, phantom and in vivo human brain data demonstrate improved performance of R-SHARP compared to V-SHARP and RESHARP (regularization enabled SHARP) methods, even when the whole paranasal sinus regions

Levels, trends and health concerns of atmospheric PAHs in Europe

NASA Astrophysics Data System (ADS)

Garrido, Adrián; Jiménez-Guerrero, Pedro; Ratola, Nuno

2014-12-01

Changes in climate can affect the concentration patterns of polycyclic aromatic hydrocarbons (PAHs) by altering the dispersion (wind speed, mixing layer height, convective fronts), deposition by precipitation, dry deposition, photochemistry, natural emissions and background concentrations. This means the evolution trends of these pollutants have to be studied under a multi-scale perspective, allowing the establishment of transport patterns and distribution of PAHs. In this sense, this work tries to unveil the atmospheric behaviour of these pollutants using temporal data series collected in different stations from the European Monitoring and Evaluation Programme (EMEP) air sampling network. These sites are thought to avoid the direct influence of emitting areas (background stations), allowing the study of long-range transport effects, intra- and trans-annual variability, relationships between concentrations patterns and meteorological variables and latitudinal gradients of PAH levels in Europe. Overall, a typical high concentration pattern was found for the colder months (and an opposite behaviour is found for summertime). Negative trends were detected over high latitudes, for instance, in Svalbard (Norway), whereas for the United Kingdom the pattern is the inverse. Also, negative latitudinal gradients were observed in 4 of the 15 PAHs studied. Finally, air quality parameters revealed concern over human health issues, given the recent increase of BaP levels in Europe.

Evaluation of aerosol sources at European high altitude background sites with trajectory statistical methods

NASA Astrophysics Data System (ADS)

Salvador, P.; Artíñano, B.; Pio, C. A.; Afonso, J.; Puxbaum, H.; Legrand, M.; Hammer, S.; Kaiser, A.

2009-04-01

During the last years, the analysis of a great number of back-trajectories from receptor sites has turned out to be a valuable tool to identify sources and sinks areas of atmospheric particulate matter (PM) or to reconstruct their average spatial distribution. A number of works have applied different trajectory statistical methods (TSM), which allow working simultaneously with back-trajectories computed from one or several receptor points and PM concentration values registered there. In spite of these methods have many limitations, they are simple and effective methods to detect the relevant source regions and the air flow regimes which are connected with regional and large-scale air pollution transport. In this study 5-day backward air trajectories arriving over 3 monitoring sites, were utilised and analysed simultaneously with the PM levels and chemical composition values registered there. These sites are located in the centre of Europe and can be classified into natural continental background (Schauinsland-SIL in Germany (1205 m asl), Puy de Dôme-PDD in France (1450 m asl) and Sonnblick-SBO in Austria (3106 m asl)). In the framework of the CARBOSOL European project, weekly aerosol samples were collected with High Volume Samplers (DIGITEL DH77) and PM10 (SIL and PDD) or PM2.5 (SBO) inlets, on quartz fibre filters. Filter samples were treated and analyzed for determining the levels of major organic fractions (OC, EC) and inorganic ions. Additionally, analyses for specific organic compounds were also carried out whenever was possible (Pio et al., 2007). For each day of the sampling period, four trajectories ending at 00:00, 06:00, 12:00 and 18:00 h UTC have been computed by the Norwegian Institute for Air Research NILU (SIL and PDD) and the Central Institute for Meteorology and Geophysics of Austria (SBO) using the FLEXTRA model (Stohl et al., 1995). In all, more than 8000 complete trajectories were available for analysis, each with 40 endpoints. Firstly air mass

Using smartphones to collect time-activity data for long-term personal-level air pollution exposure assessment.

PubMed

Glasgow, Mark L; Rudra, Carole B; Yoo, Eun-Hye; Demirbas, Murat; Merriman, Joel; Nayak, Pramod; Crabtree-Ide, Christina; Szpiro, Adam A; Rudra, Atri; Wactawski-Wende, Jean; Mu, Lina

2016-06-01

Because of the spatiotemporal variability of people and air pollutants within cities, it is important to account for a person's movements over time when estimating personal air pollution exposure. This study aimed to examine the feasibility of using smartphones to collect personal-level time-activity data. Using Skyhook Wireless's hybrid geolocation module, we developed "Apolux" (Air, Pollution, Exposure), an Android(TM) smartphone application designed to track participants' location in 5-min intervals for 3 months. From 42 participants, we compared Apolux data with contemporaneous data from two self-reported, 24-h time-activity diaries. About three-fourths of measurements were collected within 5 min of each other (mean=74.14%), and 79% of participants reporting constantly powered-on smartphones (n=38) had a daily average data collection frequency of <10 min. Apolux's degree of temporal resolution varied across manufacturers, mobile networks, and the time of day that data collection occurred. The discrepancy between diary points and corresponding Apolux data was 342.3 m (Euclidian distance) and varied across mobile networks. This study's high compliance and feasibility for data collection demonstrates the potential for integrating smartphone-based time-activity data into long-term and large-scale air pollution exposure studies.

Impacts of wildfire smoke plumes on regional air quality

EPA Science Inventory

Background: Recent trends in increased frequency and severity of large fires necessitate an improved understanding of smoke plume impacts on regional-scale air quality and public health. Objective: We examine the impact of fire smoke on regional air quality between 2006 and 2013 ...

Relationship between acceptance of background noise and hearing aid use

NASA Astrophysics Data System (ADS)

Nabelek, Anna K.; Burchfield, Samuel B.; Webster, Joanna D.

2003-04-01

Background noise produces complaints among hearing-aid users, however speech-perception-in-noise does not predict hearing-aid use. It is possible that hearing-aid users are complaining about the presence of background noise and not about speech perception. To test this possibility, acceptance of background noise is being investigated as a predictor of hearing-aid use. Acceptance of background noise is determined by having subjects select their most comfortable listening level (MCL) for a story. Next, speech-babble is added and the subjects select the maximum background noise level (BNL) which is acceptable while listening to and following the story. The difference between the MCL and the BNL is the acceptable noise level (ANL), all in dB. ANLs are being compared with hearing-aid use, subjective impressions of benefit (APHAB), speech perception in background noise (SPIN) scores, and audiometric data. Individuals who accept higher levels of background noise are more successful users than individuals who accept less background noise. Mean ANLs are 7.3 dB for full-time users (N=21), 12.6 dB for part-time users (N=44), and 13.8 dB for rejecters (N=17). ANLs are not related to APHAB, SPIN, or audiometric data. Results for about 120 subjects will be reported. [Work supported by NIDCD (NIH) RO1 DC 05018.

A piloted simulation investigation of yaw dynamics requirements for turreted gun use in low-level helicopter air combat

NASA Technical Reports Server (NTRS)

Decker, William A.; Morris, Patrick M.; Williams, Jeffrey N.

1988-01-01

A piloted, fixed-base simulation study was conducted to investigate the handling qualities requirements for helicopter air-to-air combat using turreted guns in the near-terrain environment. The study used a version of the helicopter air combat system developed at NASA Ames Research Center for one-on-one air combat. The study focused on the potential trade-off between gun angular movement capability and required yaw axis response. Experimental variables included yaw axis response frequency and damping and the size of the gun-movement envelope. A helmet position and sighting system was used for pilot control of gun aim. Approximately 340 simulated air combat engagements were evaluated by pilots from the Army and industry. Results from the experiment indicate that a highly-damped, high frequency yaw response was desired for Level I handling qualities. Pilot preference for those characteristics became more pronounced as gun turret movement was restricted; however, a stable, slow-reacting platform could be used with a large turret envelope. Most pilots preferred to engage with the opponent near the own-ship centerline. Turret elevation restriction affected the engagement more than azimuth restrictions.