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Sample records for anthropogenic lead distribution

  1. Anthropogenic lead distribution in rodent-affected and undisturbed soils in southern California

    SciTech Connect

    Mace, J.E.; Graham, R.C.; Amrhein, C.

    1997-01-01

    Anthropogenic Pb is the world`s largest and most widespread heavy metal contamination. Inspired by recent evidence suggesting a faster redistribution of Pb through the mineral soil profile than was previously expected, we investigated the effects of rodent activity on Pb redistribution. Total Pb was analyzed at the 0-1, 1-4, and 4-7-cm depths in a rodent-affected soil and in an undisturbed soil, in the same proximity and with the same parent material, in the Box Springs Mountains near Riverside, California. Six replicate sites of each condition were sampled. Lead was recovered by a digest in 4 M HNO{sub 3} and measured using a graphite furnace atomic absorption spectrophotometer. Anthropotenic Pb content to a 7-cm depth averaged 19 mg kg{sup -1} in undisturbed soils and 10 mg kg{sup -1} in rodent-affected soils. In both soils, the highest concentrations of Pb were located in the top 4 cm of the profile. After accounting for an estimated native Pb ({approximately}3.3 mg kg{sup -1}), we determined that 20 to 38 kg ha{sup -1} Pb has been deposited on these soils, through air pollution. Our findings suggest rodents significantly modify the distribution of anthropogenic Pb in the rodent-affected soils of the box Springs Mountains primarily in two ways: (i) by reducing Pb concentration in surface soils, thereby decreasing the potential for erosional redistribution of Pb, and (ii) by decreasing Pb transport time through the soil profile as a result of physical mixing. This redistribution mechanism is likely applicable to other surface deposited anthropogenic contaminants that have similarly low soil mobility. 18 refs., 1 fig., 2 tabs.

  2. Distribution and sources of pre-anthropogenic lead isotopes in deep ocean water from Fe-Mn crusts

    USGS Publications Warehouse

    Von Blanckenburg, F.; O'Nions, R. K.; Hein, J.R.

    1996-01-01

    The lead isotope composition of ocean water is not well constrained due to contamination by anthropogenic lead. Here the global distribution of lead isotopes in deep ocean water is presented as derived from dated (ca. 100 ka) surface layers of hydrogenetic Fe-Mn crusts. The results indicate that the radiogenic lead in North Atlantic deep water is probably supplied from the continents by river particulates, and that lead in Pacific deep water is similar to that characteristic of island and continental volcanic arcs. Despite a short residence time in deep water (80-100 a), the isotopes of lead appear to be exceedingly well mixed in the Pacific basin. There is no evidence for the import of North Atlantic deep water-derived lead into the Pacific ocean, nor into the North Indian Ocean. This implies that the short residence time of lead in deep water prohibits advection over such long distances. Consequently, any climate-induced changes in deep-water flow are not expected to result in major changes in the seawater Pb-isotope record of the Pacific Ocean.

  3. Inadvertent Climate Modification Due to Anthropogenic Lead

    SciTech Connect

    Cziczo, Daniel J.; Stetzer, Olaf; Worringen, Annette; Ebert, Martin; Weinbruch, Stephan; Kamphus, M.; Gallavardin, S. J.; Curtius, J.; Borrmann, S.; Froyd, Karl D.; Mertes, S.; Mohler, Ottmar; Lohmann, U.

    2009-05-01

    The relationship between atmospheric particulate matter and the formation of clouds is among the most uncertain aspects of our current understanding of climate change1. One specific question that remains unanswered is how anthropogenic particulate emissions are affecting the nucleation of ice crystals. Satellites show ice clouds cover more than a third of the globe2 and models suggest that ice nucleation initiates the majority of terrestrial precipitation3. It is therefore not possible to adequately understand either climate change or the global water cycle without understanding ice nucleation. Here we show that lead-containing particles are among the most efficient ice nucleating substances commonly found in the atmosphere. Field observations were conducted with mass spectrometry and electron microscopy at two remote stations on different continents, far removed from local emissions. Laboratory studies within two cloud chambers using controlled experimental conditions support the field data. Because the dominate sources of particulate lead are anthropogenic emissions such as aviation fuel, power generation, smelting, and the re-suspension of residue from tetra-ethyl leaded gasoline4, it is likely that cloud formation and precipitation have been affected when compared to pre-industrial times. A global climate model comparing pre-industrial and anthropogenically perturbed conditions shows that lead-containing particles may be increasing the outgoing longwave radiation by 0.2 to 0.8 W m-2, thereby offsetting a portion of the warming attributed to greenhouse gases1.

  4. Tracing the transport of anthropogenic lead in the atmosphere and in soils using isotopic ratios

    NASA Astrophysics Data System (ADS)

    Erel, Yigal; Veron, Alain; Halicz, Ludwik

    1997-11-01

    The isotopic composition of lead in aerosols and soils in Israel is used to characterize the sources of anthropogenic lead in the region, to ascertain the isotopic composition of natural, rock-derived lead in specific areas, and to determine rates of anthropogenic lead migration in soils. The isotopic composition of lead currently emitted from cars in Israel ( 206Pb /207Pb = 1.115 ± 2 ) is controlled by alkyl-lead produced in France and Germany. In addition to petrol-lead, two more sources of anthropogenic lead can be detected in sampled aerosols: the first one has low concentrations of lead (˜4 ng/m 3) and 206Pb /207Pb ˜ 1.157 , and is most likely lead, emitted in Turkey, that traveled across the eastern Mediterranean basin; the second type of aerosols contains a mixture of lead emitted in several countries including Turkey, Greece, and Ukraine ( 206Pb /207Pb value of 1.155-1.160; [Pb] ˜ 20-30 ng/m 3). Anthropogenic lead is more accessible for acid leaching than natural lead, therefore, it is more labile in the soil. The isotopic composition of lead in the acid-leached fraction of near-road soil profiles record the histor of alkyl-lead emission in the country. Based on changes in the isotopic composition of lead with soil depth, it is estimated that anthropogenic lead migrates into the soil at approximately 0.5 cm/y. A soil profile from a relatively remote area is less contaminated by anthropogenic lead and displays a different distribution of lead isotopic values with depth. The isotopic composition of lead suggests that natural lead in soils developed on carbonate bedrock is derived from clays, either from the rock-esidue (the clay fraction in the carbonate bedrock), or from airborne clay, but not from lead released from the carbonate fraction in the rock.

  5. The Impact of Anthropogenic Lead on Atmospheric Ice Formation

    NASA Astrophysics Data System (ADS)

    Cziczo, D. J.; Stetzer, O.; Demott, P. J.; Kamphus, M.; Curtius, J.; Mertes, S.; Moehler, O.; Lohmann, U.

    2008-12-01

    It is now highly certain that anthropogenic activities have caused a warming of the Earth's atmosphere. The addition of small aerosol particles has offset, to some extent, the warming attributed to greenhouse gases via the so-called 'direct effect'. Aerosol particles can also act as sites of condensation and lead to the formation of clouds and this is termed an 'indirect effect'. Some specific particles, known as ice nuclei (IN), are highly efficient at the nucleation of water ice and thus the formation of ice and mixed-phase clouds. Whereas the vast majority of atmospheric particles require temperatures of 233 K and lower and saturations near that of liquid water, IN can form ice within a few degrees below the equilibrium freezing point of liquid water and at saturations of water ice. Some lead-containing substances, for example lead iodide, are highly effective IN and this material has been used in cloud seeding studies. We have now studied anthropogenic lead emitted to the atmosphere as it impacts the formation of ice. Field work conducted on two mountaintop sites and subsequent laboratory studies show that anthropogenic lead can lead to the enhancement of ice nucleation by pre-existing atmospheric particles and, thus, the formation of clouds.

  6. Stable lead isotopes evidence anthropogenic contamination in Alaskan sea otters

    SciTech Connect

    Smith, D.R.; Estes, J.A.; Flegal, A.R. ); Niemeyer, S. )

    1990-10-01

    Lead concentrations and stable isotopic compositions were measured in teeth of preindustrial and contemporary sea otters (Enhydra lutris) from Amchitka Island, AK, to determine if changes had occurred in the magnitude and source of assimilated lead. Although there was no significant difference in lead concentrations between the two groups of otters ({bar x} {plus minus} {sigma}Pb/Ca atomic = 3.6 {plus minus} 2.9 {times} 10{sup {minus}8}), differences in stable lead isotopic compositions revealed a pronounced change in the source of accumulated lead. Lead {bar x} {plus minus} 2{sigma}{sub {bar x}} in the preindustrial otters ({sup 207}Pb/{sup 206}Pb = 0.828 {plus minus} 0.006) was derived from natural deposits in the Aleutian arc, while lead in the contemporary animals ({sup 207}Pb/{sup 206}Pb = 0.856 {plus minus} 0.003) was primarily industrial lead from Asia and western Canada. The isotopic ratios demonstrate anthropogenic perturbations of the lead cycle in present-day coastal food webs and indicate that lead concentration measurements alone are inadequate in assessing the introduction and transport of contaminant lead in the environment.

  7. Anthropogenic lead inputs to the western Pacific during the 20th century.

    PubMed

    Inoue, Mayuri; Tanimizu, Masaharu

    2008-11-15

    Unlike in the North Atlantic, no continuous record of anthropogenic lead (Pb) has been available in the western Pacific. We reconstructed historical changes in anthropogenic Pb on the basis of Pb isotope ratios recorded in annually-banded coral retrieved from Ogasawara Island, Japan. Whereas the predominant natural source of Pb to the surface of the western Pacific apparently is Chinese loess, anthropogenic Pb has affected the western Pacific at least since the late 19th century. From the late 19th to the early 20th century, Australian Pb used in Japan was an important source of anthropogenic Pb. During 1920-1940, Pb emitted from parts of the world other than Japan contributed somewhat to the western Pacific, and the amount of Pb imported from Australia declined. Alkyl Pb used in Japan became the main source from 1950 until the mid-1970s, when leaded gasoline began to be regulated in Japan. Since the mid-1980s, aerosols from China have been the predominant source of Pb in the western Pacific. During the 1990s, around 60% of Pb in the surface of the western Pacific was from Chinese aerosols. We also investigated the present spatial distribution and likely sources of Pb in the western Pacific by using coral samples. Enrichment in 208Pb, which is a characteristic of Pb from China, was found in all coral samples except that from Pohnpei, Micronesia, suggesting that at present anthropogenic Pb is transported to the western Pacific mainly from China via westerly winds.

  8. Anthropogenic influence on the distribution of tropospheric sulphate aerosol

    NASA Astrophysics Data System (ADS)

    Langner, J.; Rodhe, H.; Crutzen, P. J.; Zimmermann, P.

    1992-10-01

    HUMAN activities have increased global emissions of sulphur gases by about a factor of three during the past century, leading to increased sulphate aerosol concentrations, mainly in the Northern Hemisphere. Sulphate aerosols can affect the climate directly, by increasing the backscattering of solar radiation in cloud-free air, and indirectly, by providing additional cloud condensation nuclei1-4. Here we use a global transport-chemistry model to estimate the changes in the distribution of tropospheric sulphate aerosol and deposition of non-seasalt sulphur that have occurred since pre-industrial times. The increase in sulphate aerosol concentration is small over the Southern Hemisphere oceans, but reaches a factor of 100 over northern Europe in winter. Our calculations indicate, however, that at most 6% of the anthropogenic sulphur emissions is available for the formation of new aerosol particles. This is because about one-half of the sulphur dioxide is deposited on the Earth's surface, and most of the remainder is oxidized in cloud droplets so that the sulphate becomes associated with pre-existing particles. Even so, the rate of formation of new sulphate particles may have doubled since pre-industrial times.

  9. Tracing geogenic and anthropogenic sources in urban dusts: Insights from lead isotopes

    NASA Astrophysics Data System (ADS)

    Del Rio-Salas, R.; Ruiz, J.; De la O-Villanueva, M.; Valencia-Moreno, M.; Moreno-Rodríguez, V.; Gómez-Alvarez, A.; Grijalva, T.; Mendivil, H.; Paz-Moreno, F.; Meza-Figueroa, D.

    2012-12-01

    Tracing the source of metals in the environment is critical to understanding their pollution level and fate. Geologic materials are an important source of airborne particulate matter, but the contribution of contaminated soil to concentrations of Pb in airborne dust is not yet widely documented. To examine the potential significance of this mechanism, surface soil samples were collected, as well as wind-transported dust trapped at 1 and 2 m height at seven different locations including residential, industrial, high-traffic and rural sites. Samples of dust deposited on roofs from 24 schools were also obtained and analyzed for Pb isotope ratios. Spatial distribution of Pb of airborne and sedimented dust suggests a process dominated by re-suspension/sedimentation, which was controlled by erosion, traffic and topography of the urban area. Anthropogenic lead input in the city grades outward the urban zone toward geogenic values. Our results shows that Pb-isotopic signatures of leaded gasoline are imprinted in dust sedimented on roofs. Considering that leaded-gasoline has not been in use in Mexico since two decades ago, this signature shows not only a Pb-legacy in soil, but also a re-suspension process affecting air column below 3 m in height. The combination of the 207Pb/206Pb data of the surrounding rocks and urban dust, reveal three well-defined zones with remarkable anthropogenic influence, which correspond to the oldest urban sectors. This work highlights the importance of spatial characterization of metals in particles suspended below a height of 3 m of the airborne column, a fact that should be considered to identify exposure paths to humans and the potential risks. Lead isotope signatures allowed the identification of geogenic and anthropogenic emission sources for dust, a matter that deserves consideration in the efforts to control airborne metal emissions.

  10. Detection and calibration of anthropogenic lead emission in coastal sediments of China during the past 250 years.

    PubMed

    Zhou, Xin; Sun, Liguang; Liu, Yi; Jia, Nan; Cheng, Wenhan; Wang, Yuhong

    2015-10-01

    The historical fluctuation of lead (Pb) content in coastal sediments of China and its link with human activities have been extensively studied. However, the determined Pb profiles from even the same regions could contradict each other, likely due to the fact that different methods are used in detecting anthropogenic Pb emission. In the present study, we analyzed grain size distribution and Pb levels in three sediment cores from Chinese coastal areas, and observed a significant enrichment of Pb in the sediment fraction of fine grain size. Based upon this observation, we normalized the Pb concentrations during the past 250 years by fine grain size content. The normalized Pb profiles showed consistent, increasing trends in the three cores and a remarkable rise after the Industrial Revolution. The regional characteristics in the normalized Pb profiles of Chinese offshore sediments are consistent with those of terrestrial sediments. This new normalization method is robust and cost-effective for studying anthropogenic Pb emissions in coastal sediments.

  11. Anthropogenic lead concentrations and sources in Baltic Sea sediments based on lead isotopic composition.

    PubMed

    Zaborska, Agata

    2014-08-15

    The Gulf of Gdańsk is influenced by heavy metals of anthropogenic origin. In this study, temporal concentration changes of Pb, Zn, Cd, and Cu were studied in six, 50 cm long sediment cores. The main aim of the study was to concentrate on the history of Pb fluxes and Pb isotopic composition ((206)Pb/(207)Pb and (208)Pb/(206)Pb) to trace Pb sources. The lowest Pb concentrations (19 μg g(-1)) were measured in sediments deposited circa 1860, while the highest Pb concentrations (63-147 μg g(-1)) were measured in sediments deposited between 1960s and 70s. Pre-industrial Pb fluxes were 7 Pb m(2)year(-1), while after WWII they reached 199 Pb m(2)year(-1). Highest (206)Pb/(207)Pb ratios (∼1.22) were measured in the oldest sediment layers, and the lowest (206)Pb/(207)Pb ratios (∼1.165) were measured in the sediments deposited in 1970s-90s. During the period of highest Pb contamination, the anthropogenic Pb fraction reached up to 93%. A general discussion of the Pb sources, emissions, and loads for Poland is included.

  12. Lead isotopic composition of insoluble particles from widespread mountain glaciers in western China: Natural vs. anthropogenic sources

    NASA Astrophysics Data System (ADS)

    Yu, Guangming; Xu, Jianzhong; Kang, Shichang; Zhang, Qianggong; Huang, Jie; Ren, Qian; Ren, Jiawen; Qin, Dahe

    2013-08-01

    Stable lead (Pb) isotopic fingerprints provide opportunities to trace natural and anthropogenic Pb sources in the environment. In order to evaluate Pb deposition from different sources over mountainous areas of western China, Pb isotopic compositions were characterized from modern aeolian dust in 15 snowpit samples collected from 13 typical mountain glaciers between 2008 and 2010. Most of the snowpits sampled cover more than a whole year of accumulation and overlap with each other on deposition date. Pb isotopic variability among all the samples is small, varying in the range of 18.1399-18.9199 for 206Pb/204Pb, 15.5979-15.8743 for 207Pb/204Pb, 38.2272-39.9453 for 208Pb/204Pb, 1.1605-1.2009 for 206Pb/207Pb and 2.4433-2.5182 for 208Pb/207Pb. Three isotopic plots of the different Pb isotope ratios (207Pb/204Pb vs. 206Pb/204Pb, 208Pb/204Pb vs. 206Pb/204Pb, and 208Pb/207Pb vs. 206Pb/207Pb) in all the samples show identical geographic trends, with more radiogenic in the south and less in the north. This trend is consistent with the distribution of natural dust sources and supports the interpretation of a regional/local source for insoluble particles (IP) to snow/glaciers in this region. Comparison with the Pb isotope results from potential dust sources, however, it shows that the Pb isotopic compositions of IP samples in snow samples are relatively less radiogenic. Parts of these less-radiogenic Pb isotopes are comparable with the ice core results during recent decades, which are shown to be influenced by anthropogenic sources. At sites located along the periphery of western China, the Pb isotopic compositions are much closer to anthropogenic results. Natural and anthropogenic Pb sources are roughly assessed using a simple binary model. The sites with a high anthropogenic fraction are at lower elevations and are relatively close to population centers.

  13. Anthropogenic atmospheric nickel emissions and its distribution characteristics in China.

    PubMed

    Tian, H Z; Lu, L; Cheng, K; Hao, J M; Zhao, D; Wang, Y; Jia, W X; Qiu, P P

    2012-02-15

    Nickel and its compounds are considered as potential human carcinogens, and atmospheric nickel is one of the major routes for human exposure. By applying the best available fuel-based or product-based emission factors and annual activity levels, a multiple-year comprehensive inventory of anthropogenic atmospheric nickel emissions in China is presented with temporal trend and spatial resolutions for the period of 1980-2009 from both fuels combustion sources and industrial producing processes. We estimate that the total atmospheric nickel emissions from all the sources have increased from 1096.07 t in 1980 to 3933.71 t in 2009, at an average annual growth rate of 4.5%. Therein, coal combustion is the leading source, attributing 63.4% of the national total nickel emissions in 2009; liquid fuels consumption ranks the second, contributing 12.4% of the totals; biofuels burning accounts for 8.4% and the remaining sources together contribute 15.8% of the totals. Significant spatial variations are demonstrated among provincial emissions and the most concentrated regions are the highly industrialized and densely populated areas like the Yangtze River Delta, the Pearl River Delta and the Beijing-Tianjin-Hebei region. Moreover, the overall uncertainties are estimated at -32.6%-37.7% by using Monte Carlo simulation, most of which come from non-ferrous metals smelting category, implying the urgent need for further investigation and field tests. This article may help to combat the increasing stress on air heavy metals pollution in China and provide useful information to calculate global mass balance models for hazardous trace elements. PMID:22236636

  14. Anthropogenic atmospheric nickel emissions and its distribution characteristics in China.

    PubMed

    Tian, H Z; Lu, L; Cheng, K; Hao, J M; Zhao, D; Wang, Y; Jia, W X; Qiu, P P

    2012-02-15

    Nickel and its compounds are considered as potential human carcinogens, and atmospheric nickel is one of the major routes for human exposure. By applying the best available fuel-based or product-based emission factors and annual activity levels, a multiple-year comprehensive inventory of anthropogenic atmospheric nickel emissions in China is presented with temporal trend and spatial resolutions for the period of 1980-2009 from both fuels combustion sources and industrial producing processes. We estimate that the total atmospheric nickel emissions from all the sources have increased from 1096.07 t in 1980 to 3933.71 t in 2009, at an average annual growth rate of 4.5%. Therein, coal combustion is the leading source, attributing 63.4% of the national total nickel emissions in 2009; liquid fuels consumption ranks the second, contributing 12.4% of the totals; biofuels burning accounts for 8.4% and the remaining sources together contribute 15.8% of the totals. Significant spatial variations are demonstrated among provincial emissions and the most concentrated regions are the highly industrialized and densely populated areas like the Yangtze River Delta, the Pearl River Delta and the Beijing-Tianjin-Hebei region. Moreover, the overall uncertainties are estimated at -32.6%-37.7% by using Monte Carlo simulation, most of which come from non-ferrous metals smelting category, implying the urgent need for further investigation and field tests. This article may help to combat the increasing stress on air heavy metals pollution in China and provide useful information to calculate global mass balance models for hazardous trace elements.

  15. Dispersal of natural and anthropogenic lead through submarine canyons at the Portuguese margin

    NASA Astrophysics Data System (ADS)

    Richter, T. O.; de Stigter, H. C.; Boer, W.; Jesus, C. C.; van Weering, T. C. E.

    2009-02-01

    Submarine canyons represent natural conduits for preferential transport of particulate material, including anthropogenic contaminants, from coastal zones directly to the deep sea. To assess related dispersal of natural and anthropogenic lead (Pb), we analyzed Pb concentrations and stable isotope ratios in surface sediments and sediment trap particulate material from the Portuguese margin Nazaré and Setúbal/Lisbon canyons. Geochemical data are integrated with previously obtained data on near-bottom hydrodynamics and processes and pathways of sediment transport. The two canyon systems are located in close geographic proximity to each other, but represent contrasting settings in terms of sediment input and down-canyon sediment transport processes. Concentration-isotope diagrams and three-isotope plots ( 206Pb/ 207Pb vs. 208Pb/ 206Pb) suggest binary mixing between natural and anthropogenic end members. The inferred isotopic signature of pollutant Pb ( 206Pb/ 207Pb=1.143 [1.134-1.149, 95% confidence interval]) is most consistent with industrial Pb; ongoing influence from gasoline Pb additives is at most of minor importance. Two proposed natural end members most likely bracket the isotopic signature of natural Pb. Accordingly, binary mixing calculations indicate that on average 20-45% vs. 35-55% of total Pb is derived from anthropogenic sources in the Nazaré and Setúbal-Lisbon canyon systems, respectively. Enhanced anthropogenic influence in the latter area is consistent with its proximity to heavily populated and industrialized areas and with sediment input from the Tagus and Sado rivers, potential major carriers of pollutant particles. In both canyon systems, the anthropogenic component generally decreases with increasing water depth. Isotopic signatures of sediment trap particulate material are generally consistent with surface sediment data at similar water depth, but show large variability in the upper Nazaré canyon and major deviations from surface sediments

  16. Asian anthropogenic lead contamination in the North Pacific Ocean as evidenced by stable lead isotopic compositions

    NASA Astrophysics Data System (ADS)

    Zurbrick, Cheryl M.

    This dissertation work determined the changing scope of lead (Pb) contamination in the North Pacific Ocean since the phase-out of leaded gasoline in most of the world. Chapters 1 and 2 consisted of validating our method for determining Pb concentrations and isotopic compositions in seawater. Chapter 3 established a baseline of Pb isotopic compositions (PbICs) in the western and central North Pacific in 2002. This was an ideal time to establish such a baseline because China had recently (mid-2000) ceased their use of leaded gasoline and simultaneously began consuming increasingly large amounts of coal, known to have relatively high Pb concentrations. We found subsurface waters were contaminated with Asian industrial Pb, predominantly Chinese coal emissions. In contrast, the abyssal waters were a mix of Asian industrial Pb and background (i.e., natural) Pb. Chapter 4 revisited the western and central North Pacific in 2009 -- 2011 to determine what, if any, changes had occurred in this short time period. We found that Pb in subsurface and abyssal waters of the western North Pacific were similar to Chinese aerosols. Such a large change in the PbICs of abyssal water in 9 years was unanticipated and attributed to the relatively large flux of particle-bound Pb from the euphotic zone to the deep ocean, which was in isotopic equilibrium with the reservoir of dissolved Pb. In contrast, the central North Pacific abyssal water PbICs were similar to values previously reported because of the relatively lower particulate export. Based on comparisons to baseline PbIC data, we determined that abyssal waters in the western and central North Pacific would be isotopically indistinguishable from surface waters in the next three decades. Sources of Pb to coastal California waters were reevaluated in Chapter 5. Prior studies had found that surface waters of the California Current System (CCS) were isotopically consistent with both Asian industrial Pb and US leaded gasoline, still in use

  17. Lead Isotopic Tracing of Coal-Based Anthropogenic Pollution in Agricultural Soils in Jianghan Plain, China

    NASA Astrophysics Data System (ADS)

    Daniel, J. N.; Ying, S.; Zhao, R.; Bu, J.; Gan, Y.; Wang, Y.; Weiss, D. J.; Fendorf, S. E.

    2014-12-01

    The Chinese demand for energy is one of the greatest in the world, and the vast majority of it is generated through coal combustion - a process by which diverse pollutants are released into the atmosphere. Due to the relative proximity of croplands to power plants in much of China, these pollutants can be deposited onto agricultural soils via atmospheric transport. Relative amounts of lead (Pb) isotopes in airborne anthropogenic coal-based contaminants (fly ash) are currently understood. However, contaminants' effects on agricultural soil composition are less clear. We investigate the prevalence of anthropogenic contaminants in cropland soils using lead (Pb) isotope ratios as a tracer. Surface soil samples and deep core samples, taken from Chinese field sites in proximity to a coal combustion plant, undergo an acid extraction process and lead (Pb) isotope concentrations are measured. The results of this study illustrate the extent to which airborne contaminants have entered cropland soils and integrated themselves into the chemical processes at work. They further expand our understanding of the impacts of human coal combustion activities on the biogeochemistry of agricultural soils.

  18. Sources and Evolution of Anthropogenic Lead in Northwestern Pacific Seawater: High Resolution Coral Pb Isotope Record

    NASA Astrophysics Data System (ADS)

    Wang, B.; You, C.; Nohda, S.

    2008-12-01

    Lattice-bound Lead in scleractinian coral skeletons provides a potential tracer to investigate the historical anthropogenic disturbance in the surface ocean. In this study, a Porites coral core collected from an islet offshore southeastern Taiwan was used to reconstruct decadal lead variation in surface seawater at northwestern Pacific. Seasonal Pb/Ca peaks are in accordance with rainfall episodes, while the long-term trend shows high lead input before 1970s. This can be attributed to extensively use of alkyl-lead in the region. Moreover, temporal variations of lead isotope display a significant change of lead sources in mid-20 th, coinciding with the Australian Pb imported period. These isotopic signatures also indicate contribution from China/Japan pollutant through atmospheric circulation during 1962-1998. This preliminary study infers that Pb in surface seawater is dominantly transported by ocean current and aeolian deposition from adjacent urban area, while Pb concentration may not reflect entirely the source flux due to potential loss during transportation.

  19. Use of stable lead isotopes to characterize the sources of anthropogenic lead in North Atlantic surface waters

    SciTech Connect

    Veron, A.J. Univ. of Delaware, Newark, DE ); Church, T.M. ); Patterson, C.C. ); Flegal, A.R. Univ. of California, Santa Cruz, CA )

    1994-08-01

    Stable lead isotopes are used to illustrate the impact of surface water circulation on dissolved lead distribution in North Atlantic surface waters during oligotrophic conditions. Using stable lead isotopic signatures from (1) the Sargasso Sea and (2) direct tropospheric deposition to the North Atlantic, the authors estimate that 10-40% of the lead accumulated in surface waters of the European Basin is transported from the western North Atlantic by the North Atlantic Current. South of 50[degrees]N, lead appears to be primarily distributed by the Subtropical North Atlantic Gyre that extends well beyond the western basins to 30[degrees]W in the North African Basin (at 30-40[degrees]N). There are different lead isotopic signatures between the subtropical gyre of the Guiana and western Guinea Basins, which suggests that the Inter Tropical Convergence Zone acts as an efficient barrier limiting chemical exchanges between the gyre and the equatorial currents.

  20. Metal leachability and anthropogenic signal in roadside soils estimated from sequential extraction and stable lead isotopes.

    PubMed

    Bäckström, Mattias; Karlsson, Stefan; Allard, Bert

    2004-01-01

    Several roadside soil samples were collected at two field sites in Sweden. They were analysed for total elemental content (using both ICP-MS and XRF) and stable lead isotopes. Extraction with deicing salt solution and sequential extraction were performed in order to elucidate the potential mobility due to the use of deicing agents. The total concentrations of elements, especially lead, have decreased and lead is presently almost at background concentrations (15-51 ppm for surface samples). However, the isotopic signature indicates that old gasoline lead still is left at the site constructed prior to 1975. The field site constructed in 1992 showed, however, no 206Pb/207Pb ratio below 1.14. Only minor amounts were leached using deicing salt solutions; for lead only 0.29%, on average, was extracted indicating that the mobile fraction already was released. Sequential extraction indicated that lead mainly was associated with reducible (34.4%) and oxidisable (35.4%) fractions. Exchangable and acid soluble fractions contained 20.3% while 10.0% was found in the residual fraction. The salt extraction released, however, very low concentrations indicating that most in fraction 1 is acid soluble (e.g. carbonates). Tungsten was also found at high concentrations indicating a possible impact from studded tires. For tungsten the following composition was obtained: residual (48.0%) > oxidisable (47.6%) > reducible (3.3%) > exchangeable/acid soluble (1.1%). From the isotopic studies it was also suggested that the order for incorporating anthropogenic lead into soils is exchangeable/carbonates > (hydr)oxides > organic matter > residual. The multivariate technique principal component analysis (PCA) seems promising for evaluating large sequential extraction datasets. PMID:15887369

  1. Anthropogenic litter in urban freshwater ecosystems: distribution and microbial interactions.

    PubMed

    Hoellein, Timothy; Rojas, Miguel; Pink, Adam; Gasior, Joseph; Kelly, John

    2014-01-01

    Accumulation of anthropogenic litter (i.e. garbage; AL) and its ecosystem effects in marine environments are well documented. Rivers receive AL from terrestrial habitats and represent a major source of AL to marine environments, but AL is rarely studied within freshwater ecosystems. Our objectives were to 1) quantify AL density in urban freshwaters, 2) compare AL abundance among freshwater, terrestrial, and marine ecosystems, and 3) characterize the activity and composition of AL biofilms in freshwater habitats. We quantified AL from the Chicago River and Chicago's Lake Michigan shoreline, and found that AL abundance in Chicago freshwater ecosystems was comparable to previously reported data for marine and terrestrial ecosystems, although AL density and composition differed among habitats. To assess microbial interactions with AL, we incubated AL and natural substrates in 3 freshwater ecosystems, quantified biofilm metabolism as gross primary production (GPP) and community respiration (CR), and characterized biofilm bacterial community composition via high-throughput sequencing of 16S rRNA genes. The main driver of biofilm community composition was incubation location (e.g., river vs pond), but there were some significant differences in biofilm composition and metabolism among substrates. For example, biofilms on organic substrates (cardboard and leaves) had lower GPP than hard substrates (glass, plastic, aluminum and tiles). In addition, bacterial communities on organic substrates were distinct in composition from those on hard substrates, with higher relative abundances of bacteria associated with cellulose decomposition. Finally, we used our results to develop a conceptual diagram designed to unite the study of AL in terrestrial and freshwater environments with the well-established field of marine debris research. We suggest this broad perspective will be useful for future studies which synthesize AL sources, ecosystem effects, and fate across multiple ecosystem

  2. Anthropogenic Litter in Urban Freshwater Ecosystems: Distribution and Microbial Interactions

    PubMed Central

    Hoellein, Timothy; Rojas, Miguel; Pink, Adam; Gasior, Joseph; Kelly, John

    2014-01-01

    Accumulation of anthropogenic litter (i.e. garbage; AL) and its ecosystem effects in marine environments are well documented. Rivers receive AL from terrestrial habitats and represent a major source of AL to marine environments, but AL is rarely studied within freshwater ecosystems. Our objectives were to 1) quantify AL density in urban freshwaters, 2) compare AL abundance among freshwater, terrestrial, and marine ecosystems, and 3) characterize the activity and composition of AL biofilms in freshwater habitats. We quantified AL from the Chicago River and Chicago's Lake Michigan shoreline, and found that AL abundance in Chicago freshwater ecosystems was comparable to previously reported data for marine and terrestrial ecosystems, although AL density and composition differed among habitats. To assess microbial interactions with AL, we incubated AL and natural substrates in 3 freshwater ecosystems, quantified biofilm metabolism as gross primary production (GPP) and community respiration (CR), and characterized biofilm bacterial community composition via high-throughput sequencing of 16S rRNA genes. The main driver of biofilm community composition was incubation location (e.g., river vs pond), but there were some significant differences in biofilm composition and metabolism among substrates. For example, biofilms on organic substrates (cardboard and leaves) had lower GPP than hard substrates (glass, plastic, aluminum and tiles). In addition, bacterial communities on organic substrates were distinct in composition from those on hard substrates, with higher relative abundances of bacteria associated with cellulose decomposition. Finally, we used our results to develop a conceptual diagram designed to unite the study of AL in terrestrial and freshwater environments with the well-established field of marine debris research. We suggest this broad perspective will be useful for future studies which synthesize AL sources, ecosystem effects, and fate across multiple ecosystem

  3. Anthropogenic litter in urban freshwater ecosystems: distribution and microbial interactions.

    PubMed

    Hoellein, Timothy; Rojas, Miguel; Pink, Adam; Gasior, Joseph; Kelly, John

    2014-01-01

    Accumulation of anthropogenic litter (i.e. garbage; AL) and its ecosystem effects in marine environments are well documented. Rivers receive AL from terrestrial habitats and represent a major source of AL to marine environments, but AL is rarely studied within freshwater ecosystems. Our objectives were to 1) quantify AL density in urban freshwaters, 2) compare AL abundance among freshwater, terrestrial, and marine ecosystems, and 3) characterize the activity and composition of AL biofilms in freshwater habitats. We quantified AL from the Chicago River and Chicago's Lake Michigan shoreline, and found that AL abundance in Chicago freshwater ecosystems was comparable to previously reported data for marine and terrestrial ecosystems, although AL density and composition differed among habitats. To assess microbial interactions with AL, we incubated AL and natural substrates in 3 freshwater ecosystems, quantified biofilm metabolism as gross primary production (GPP) and community respiration (CR), and characterized biofilm bacterial community composition via high-throughput sequencing of 16S rRNA genes. The main driver of biofilm community composition was incubation location (e.g., river vs pond), but there were some significant differences in biofilm composition and metabolism among substrates. For example, biofilms on organic substrates (cardboard and leaves) had lower GPP than hard substrates (glass, plastic, aluminum and tiles). In addition, bacterial communities on organic substrates were distinct in composition from those on hard substrates, with higher relative abundances of bacteria associated with cellulose decomposition. Finally, we used our results to develop a conceptual diagram designed to unite the study of AL in terrestrial and freshwater environments with the well-established field of marine debris research. We suggest this broad perspective will be useful for future studies which synthesize AL sources, ecosystem effects, and fate across multiple ecosystem

  4. Distributed electrical leads for thermionic converter

    DOEpatents

    Fitzpatrick, Gary O.; Britt, Edward J.

    1979-01-01

    In a thermionic converter, means are provided for coupling an electrical lead to at least one of the electrodes thereof. The means include a bus bar and a plurality of distributed leads coupled to the bus bar each of which penetrates through one electrode and are then coupled to the other electrode of the converter in spaced apart relation.

  5. Bayesian evaluation of groundwater age distribution using radioactive tracers and anthropogenic chemicals

    NASA Astrophysics Data System (ADS)

    Massoudieh, Arash; Sharifi, Soroosh; Solomon, D. Kip

    2012-09-01

    The development of a Bayesian modeling approach for estimation of the age distribution of groundwater using radioactive isotopes and anthropogenic chemicals is described. The model considers the uncertainties associated with the measured tracer concentrations as well as the parameters affecting the concentration of tracers in the groundwater, and it provides the posterior probability densities of the parameters defining the groundwater age distribution using a Markov chain Monte Carlo method. The model also incorporates the effect of dissolution of aquifer minerals on diluting the 14C signature and the uncertainties associated with this process on the inferred age distribution parameters. Two demonstration modeling cases have been performed. First, the method was applied to simulated tracer concentrations at a discharge point of a hypothetical 2-D vertical aquifer with two recharge zones, leading to a mixed groundwater age distribution under different presumed uncertainties. When the error variance of the observed tracer concentrations is considered unknown, the method can estimate the parameters of the fitted exponential-lognormal distribution with a relatively narrow credible interval when five hypothetical samples are assumed to be collected at the discharge point. However, when a single sample is assumed, the credible intervals become wider, and credible estimations of the parameters are not obtained. Second, the method was applied to the data collected at La Selva Biological Station in Costa Rica. In this demonstration application, nine different forms of presumed groundwater age distributions have been considered, including four single forms and five mixed forms, assuming the groundwater consists of distinct young and old fractions. For the medium geometrical standard deviationδc,i = 1.41, the model estimates a young groundwater age of between 0 and 350 years, with the largest odds being given to a mean age of approximately 100 years, and a fraction of young

  6. Mapping the spatial distribution of global anthropogenic mercury atmospheric emission inventories

    NASA Astrophysics Data System (ADS)

    Wilson, Simon J.; Steenhuisen, Frits; Pacyna, Jozef M.; Pacyna, Elisabeth G.

    This paper describes the procedures employed to spatially distribute global inventories of anthropogenic emissions of mercury to the atmosphere, prepared by Pacyna, E.G., Pacyna, J.M., Steenhuisen, F., Wilson, S. [2006. Global anthropogenic mercury emission inventory for 2000. Atmospheric Environment, this issue, doi:10.1016/j.atmosenv.2006.03.041], and briefly discusses the results of this work. A new spatially distributed global emission inventory for the (nominal) year 2000, and a revised version of the 1995 inventory are presented. Emissions estimates for total mercury and major species groups are distributed within latitude/longitude-based grids with a resolution of 1×1 and 0.5×0.5°. A key component in the spatial distribution procedure is the use of population distribution as a surrogate parameter to distribute emissions from sources that cannot be accurately geographically located. In this connection, new gridded population datasets were prepared, based on the CEISIN GPW3 datasets (CIESIN, 2004. Gridded Population of the World (GPW), Version 3. Center for International Earth Science Information Network (CIESIN), Columbia University and Centro Internacional de Agricultura Tropical (CIAT). GPW3 data are available at http://beta.sedac.ciesin.columbia.edu/gpw/index.jsp). The spatially distributed emissions inventories and population datasets prepared in the course of this work are available on the Internet at www.amap.no/Resources/HgEmissions/

  7. Lead distribution in coastal and estuarine sediments around India.

    PubMed

    Chakraborty, Sucharita; Chakraborty, Parthasarathi; Nath, B Nagender

    2015-08-15

    This study describes the geochemical distribution of lead (Pb) and identifies the critical factors that significantly control Pb distribution and speciation in coastal and estuarine sediments around India by using published data from the literature. Crustal sources influence the abundance of Pb in coastal sediment from the south-east and central-west coast of India. Parts of north-east, north-west, and south-west coast of India were polluted by Pb. Distribution of Pb in sediments, from the north-east and north-west coasts of India, were controlled by Fe-Mn oxyhydroxide mineral phases of the sediments. However, organic carbon (OC) seemed to be a dominant factor in controlling the distribution of Pb in sediments from the central-east and south-west coasts of India. The outcome of this study may help in decision-making to predict the levels of Pb from natural and anthropogenic sources and to control Pb pollution in coastal and estuarine sediments around India.

  8. Aerosol Size Distribution Response to Anthropogenically Driven Historical Changes in Biogenic Secondary Organic Aerosol Formation

    NASA Astrophysics Data System (ADS)

    Pierce, J. R.; D'Andrea, S.; Acosta Navarro, J. C.; Farina, S.; Scott, C.; Farmer, D. K.; Spracklen, D. V.; Riipinen, I.

    2014-12-01

    Emissions of biological volatile organic compounds (BVOC) have changed in the past millennium due to changes in land use, temperature and CO2 concentrations. A recent model reconstruction of BVOC emissions over the past millennium predicted the changes in the three dominant secondary organic aerosol (SOA) producing BVOC classes (isoprene, monoterpenes and sesquiterpenes). The reconstruction predicted that in global averages isoprene emissions have decreased (land-use changes to crop/grazing land dominate the reduction), while monoterpene and sesquiterpene emissions have increased (temperature increases dominate the increases); however, all three show both increases and decreases in certain regions due to competition between the various influencing factors. These BVOC changes have largely been anthropogenic in nature, and land-use change was shown to have the most dramatic effect by decreasing isoprene emissions. We use these modeled estimates of these three dominant BVOC classes' emissions from the years 1000 to 2000 to test the effect of anthropogenic changes to BVOC emissions on SOA formation and global aerosol size distributions using the GEOS-Chem-TOMAS global aerosol microphysics model. With anthropogenic emissions (e.g. SO2, NOx, primary aerosols) held at present day values and BVOC emissions changed from year 1000 to year 2000 values, decreases in the number concentration of particles of size Dp > 80 nm (N80) of >25% in year 2000 relative to year 1000 were predicted in regions with extensive land-use changes since year 1000. This change in N80 was predominantly driven by a shift towards crop/grazing land that produces less BVOC than the natural vegetation. Similar sensitivities to year 1000 vs. year 2000 BVOC emissions exist when anthropogenic emissions are turned off. This large decrease in N80 could be a largely overlooked and important anthropogenic aerosol effect on regional climates.

  9. Transient tracer distributions in the Fram Strait in 2012 and inferred anthropogenic carbon content and transport

    NASA Astrophysics Data System (ADS)

    Stöven, Tim; Tanhua, Toste; Hoppema, Mario; von Appen, Wilken-Jon

    2016-02-01

    The storage of anthropogenic carbon in the ocean's interior is an important process which modulates the increasing carbon dioxide concentrations in the atmosphere. The polar regions are expected to be net sinks for anthropogenic carbon. Transport estimates of dissolved inorganic carbon and the anthropogenic offset can thus provide information about the magnitude of the corresponding storage processes. Here we present a transient tracer, dissolved inorganic carbon (DIC) and total alkalinity (TA) data set along 78°50' N sampled in the Fram Strait in 2012. A theory on tracer relationships is introduced, which allows for an application of the inverse-Gaussian-transit-time distribution (IG-TTD) at high latitudes and the estimation of anthropogenic carbon concentrations. Mean current velocity measurements along the same section from 2002-2010 were used to estimate the net flux of DIC and anthropogenic carbon by the boundary currents above 840 m through the Fram Strait. The new theory explains the differences between the theoretical (IG-TTD-based) tracer age relationship and the specific tracer age relationship of the field data, by saturation effects during water mass formation and/or the deliberate release experiment of SF6 in the Greenland Sea in 1996, rather than by different mixing or ventilation processes. Based on this assumption, a maximum SF6 excess of 0.5-0.8 fmol kg-1 was determined in the Fram Strait at intermediate depths (500-1600 m). The anthropogenic carbon concentrations are 50-55 µmol kg-1 in the Atlantic Water/Recirculating Atlantic Water, 40-45 µmol kg-1 in the Polar Surface Water/warm Polar Surface Water and between 10 and 35 µmol kg-1 in the deeper water layers, with lowest concentrations in the bottom layer. The net fluxes through the Fram Strait indicate a net outflow of ˜ 0.4 DIC and ˜ 0.01 PgC yr-1 anthropogenic carbon from the Arctic Ocean into the North Atlantic, albeit with high uncertainties.

  10. Effects of grinding and shaking on Cd, Pb and Zn distribution in anthropogenically impacted soils.

    PubMed

    Waterlot, Christophe; Bidar, Géraldine; Pruvot, Christelle; Douay, Francis

    2012-08-30

    The effects of grinding size and shaking process on the results of Cd (cadmium), Pb (lead) and Zn (zinc) distribution measurements three agricultural and three kitchen garden soils highly contaminated by past atmospheric fallout of two lead and zinc smelters in northern France were studied. The physico-chemical parameters and pseudo-total concentration of metals within these soils were determined. The fractionation of metals was performed in triplicate, using the procedure recommended by the Standards, Measurements and Testing program (SM&T), on each air-dried soil sample, ground to pass through 2-mm, 0.315-mm and 0.250-mm sieves and using a reciprocating or rotary shaker. The samples were analysed by flame or electrothermal absorption atomic spectrometry using a self-reversal background system. For both shaking processes, the grinding size had no effect on the fractionation of metals in contaminated agricultural soils. In contrast, using a reciprocating shaker, the fractionation of metals in the kitchen garden samples sieved at <2mm was so different that in the samples prepared to pass through the 0.315-mm and 0.250-mm sieves. Therefore changes (use of a 50 mL graduated polypropylene centrifuge tube, evaporation of the solution to a fixed volume in step 3 and the use of an automatic shaking heating bath) were made to the initial procedure and a rotary shaker was used to improve the suspension of the soil samples during extraction. For all grinding sizes, the fractionation of the three metals contained in the contaminated kitchen garden soil samples was successfully achieved. Nevertheless, some discrepancies from samples sieved at <2mm were obtained. On the other hand, it is worth noting that the effect of the type of shaker on the distribution of metal depended on the soil and the grinding size. From an analytical point of view, precision and trueness were improved after optimisation of the procedure for all sequential extraction procedure steps. The best results

  11. Effects of grinding and shaking on Cd, Pb and Zn distribution in anthropogenically impacted soils.

    PubMed

    Waterlot, Christophe; Bidar, Géraldine; Pruvot, Christelle; Douay, Francis

    2012-08-30

    The effects of grinding size and shaking process on the results of Cd (cadmium), Pb (lead) and Zn (zinc) distribution measurements three agricultural and three kitchen garden soils highly contaminated by past atmospheric fallout of two lead and zinc smelters in northern France were studied. The physico-chemical parameters and pseudo-total concentration of metals within these soils were determined. The fractionation of metals was performed in triplicate, using the procedure recommended by the Standards, Measurements and Testing program (SM&T), on each air-dried soil sample, ground to pass through 2-mm, 0.315-mm and 0.250-mm sieves and using a reciprocating or rotary shaker. The samples were analysed by flame or electrothermal absorption atomic spectrometry using a self-reversal background system. For both shaking processes, the grinding size had no effect on the fractionation of metals in contaminated agricultural soils. In contrast, using a reciprocating shaker, the fractionation of metals in the kitchen garden samples sieved at <2mm was so different that in the samples prepared to pass through the 0.315-mm and 0.250-mm sieves. Therefore changes (use of a 50 mL graduated polypropylene centrifuge tube, evaporation of the solution to a fixed volume in step 3 and the use of an automatic shaking heating bath) were made to the initial procedure and a rotary shaker was used to improve the suspension of the soil samples during extraction. For all grinding sizes, the fractionation of the three metals contained in the contaminated kitchen garden soil samples was successfully achieved. Nevertheless, some discrepancies from samples sieved at <2mm were obtained. On the other hand, it is worth noting that the effect of the type of shaker on the distribution of metal depended on the soil and the grinding size. From an analytical point of view, precision and trueness were improved after optimisation of the procedure for all sequential extraction procedure steps. The best results

  12. Cascading impacts of anthropogenically driven habitat loss: deforestation, flooding, and possible lead poisoning in howler monkeys (Alouatta pigra).

    PubMed

    Serio-Silva, Juan Carlos; Olguín, Eugenia J; Garcia-Feria, Luis; Tapia-Fierro, Karla; Chapman, Colin A

    2015-01-01

    To construct informed conservation plans, researchers must go beyond understanding readily apparent threats such as habitat loss and bush-meat hunting. They must predict subtle and cascading effects of anthropogenic environmental modifications. This study considered a potential cascading effect of deforestation on the howler monkeys (Alouatta pigra) of Balancán, Mexico. Deforestation intensifies flooding. Thus, we predicted that increased flooding of the Usumacinta River, which creates large bodies of water that slowly evaporate, would produce increased lead content in the soils and plants, resulting in lead exposure in the howler monkeys. The average lead levels were 18.18 ± 6.76 ppm in the soils and 5.85 ± 4.37 ppm in the plants. However, the average lead content of the hair of 13 captured howler monkeys was 24.12 ± 5.84 ppm. The lead levels in the animals were correlated with 2 of 15 blood traits (lactate dehydrogenase and total bilirubin) previously documented to be associated with exposure to lead. Our research illustrates the urgent need to set reference values indicating when adverse impacts of high environmental lead levels occur, whether anthropogenic or natural, and the need to evaluate possible cascading effects of deforestation on primates.

  13. Cascading impacts of anthropogenically driven habitat loss: deforestation, flooding, and possible lead poisoning in howler monkeys (Alouatta pigra).

    PubMed

    Serio-Silva, Juan Carlos; Olguín, Eugenia J; Garcia-Feria, Luis; Tapia-Fierro, Karla; Chapman, Colin A

    2015-01-01

    To construct informed conservation plans, researchers must go beyond understanding readily apparent threats such as habitat loss and bush-meat hunting. They must predict subtle and cascading effects of anthropogenic environmental modifications. This study considered a potential cascading effect of deforestation on the howler monkeys (Alouatta pigra) of Balancán, Mexico. Deforestation intensifies flooding. Thus, we predicted that increased flooding of the Usumacinta River, which creates large bodies of water that slowly evaporate, would produce increased lead content in the soils and plants, resulting in lead exposure in the howler monkeys. The average lead levels were 18.18 ± 6.76 ppm in the soils and 5.85 ± 4.37 ppm in the plants. However, the average lead content of the hair of 13 captured howler monkeys was 24.12 ± 5.84 ppm. The lead levels in the animals were correlated with 2 of 15 blood traits (lactate dehydrogenase and total bilirubin) previously documented to be associated with exposure to lead. Our research illustrates the urgent need to set reference values indicating when adverse impacts of high environmental lead levels occur, whether anthropogenic or natural, and the need to evaluate possible cascading effects of deforestation on primates. PMID:25163777

  14. Application of lead isotopic methods to the study of the anthropogenic lead provenance in Spanish overbank floodplain deposits.

    PubMed

    Adánez Sanjuán, Paula; Flem, Belinda; Llamas Borrajo, Juan F; Locutura Rupérez, Juan; Garcia Cortés, Angel

    2016-04-01

    Changes in the principal sources of Pb in overbank sediment profiles have been documented for two Spanish areas by using Pb isotopes and Pb concentrations. These locations (Madrid and Tinto-Odiel basin) represent two of the most contaminated regions in Spain. The Community of Madrid is characterized by heavy industrial and urban activity, focused mainly in Madrid City. The Tinto-Odiel basin drains the Iberian Pyrite Belt, which hosts many polymetallic massive sulphides and is heavily affected by mining activities in their headwaters. It has been proven that the influence of anthropogenic activity is reflected in these overbank deposits by variations in Pb concentrations that, in general, correlate with shifts in the (206)Pb/(207)Pb ratio. Rivas profile (downstream of Madrid) was found to be the most anthropogenically influenced site. The sediments within this profile which were recently deposited (170 ± 40 years BP) have the least radiogenic signatures. (206)Pb/(207)Pb ratios ranged between 1.1763 and 1.1876 indicating significant contributions of anthropogenic Pb. In contrast, profiles upstream of Madrid possess an average (206)Pb/(207)Pb ratio of 1.2272. It is difficult to clearly identify the most prominent source as the sediments appear to be characterized by an input from several sources. The floodplain profiles in the Tinto-Odiel basin exhibit uniform (206)Pb/(207)Pb ratios ranging from 1.1627 (Odiel river) to 1.1665 (Tinto river). These ratios are similar to the ones possessed by sulphide ores in the area and differ from the ratios of other nonmineralized formations in the basin, indicating that mining activities are the primary, if not sole, source of Pb to the sediments. PMID:26100323

  15. Spatial distribution of lead in Sacramento, California, USA.

    PubMed

    Solt, Michael J; Deocampo, Daniel M; Norris, Michelle

    2015-03-17

    Chronic exposure to lead remains a health concern in many urban areas; Sacramento, California is one example, with state surveillance data showing nearly 3% of screened children reported with blood lead levels over 4.5 μg/dL in 2009. To investigate the environmental exposure, 91 soil samples were collected and analyzed by ICP-AES and ICP-MS for 14 elements. An additional 28 samples were collected from areas of focus and analyzed by hand-held X-ray fluorescence spectrometry for Pb and Zn. Analysis of the metals data revealed non-normal distributions and positive skewness, consistent with anthropogenic input. In addition, high correlation coefficients (≥0.75) of metal concentrations in Cd-Pb, Cd-Zn, Pb-Zn, and Sb-Sn pairs suggest similarities in the input mechanisms. Semivariograms generated from Pb and associated metals reveal these metals to exhibit spatial correlation. A prediction map of lead concentrations in soil was generated by ordinary kriging, showing elevated concentrations in soil located in the central, older area of Sacramento where historic traffic density and industrial activity have been historically concentrated. XRF analysis of Pb and Zn from additional samples verifies elevated concentrations in the central areas of Sacramento as predicted.

  16. Spatial distribution of lead in Sacramento, California, USA.

    PubMed

    Solt, Michael J; Deocampo, Daniel M; Norris, Michelle

    2015-03-01

    Chronic exposure to lead remains a health concern in many urban areas; Sacramento, California is one example, with state surveillance data showing nearly 3% of screened children reported with blood lead levels over 4.5 μg/dL in 2009. To investigate the environmental exposure, 91 soil samples were collected and analyzed by ICP-AES and ICP-MS for 14 elements. An additional 28 samples were collected from areas of focus and analyzed by hand-held X-ray fluorescence spectrometry for Pb and Zn. Analysis of the metals data revealed non-normal distributions and positive skewness, consistent with anthropogenic input. In addition, high correlation coefficients (≥0.75) of metal concentrations in Cd-Pb, Cd-Zn, Pb-Zn, and Sb-Sn pairs suggest similarities in the input mechanisms. Semivariograms generated from Pb and associated metals reveal these metals to exhibit spatial correlation. A prediction map of lead concentrations in soil was generated by ordinary kriging, showing elevated concentrations in soil located in the central, older area of Sacramento where historic traffic density and industrial activity have been historically concentrated. XRF analysis of Pb and Zn from additional samples verifies elevated concentrations in the central areas of Sacramento as predicted. PMID:25789455

  17. Spatial Distribution of Lead in Sacramento, California, USA

    PubMed Central

    Solt, Michael J.; Deocampo, Daniel M.; Norris, Michelle

    2015-01-01

    Chronic exposure to lead remains a health concern in many urban areas; Sacramento, California is one example, with state surveillance data showing nearly 3% of screened children reported with blood lead levels over 4.5 μg/dL in 2009. To investigate the environmental exposure, 91 soil samples were collected and analyzed by ICP-AES and ICP-MS for 14 elements. An additional 28 samples were collected from areas of focus and analyzed by hand-held X-ray fluorescence spectrometry for Pb and Zn. Analysis of the metals data revealed non-normal distributions and positive skewness, consistent with anthropogenic input. In addition, high correlation coefficients (≥0.75) of metal concentrations in Cd-Pb, Cd-Zn, Pb-Zn, and Sb-Sn pairs suggest similarities in the input mechanisms. Semivariograms generated from Pb and associated metals reveal these metals to exhibit spatial correlation. A prediction map of lead concentrations in soil was generated by ordinary kriging, showing elevated concentrations in soil located in the central, older area of Sacramento where historic traffic density and industrial activity have been historically concentrated. XRF analysis of Pb and Zn from additional samples verifies elevated concentrations in the central areas of Sacramento as predicted. PMID:25789455

  18. Natural and anthropogenic radionuclide distributions in the Nansen Basin, Artic Ocean: Scavenging rates and circulation timescales

    NASA Astrophysics Data System (ADS)

    Kirk Cochran, J.; Hirschberg, David J.; Livingston, Hugh D.; Buesseler, Ken O.; Key, Robert M.

    Determination of the naturally occurring radionuclides 232Th, 230Th, 228 Th and 210Pb, and the anthropogenic radionuclides 241Am, 239,240Pu, 134Cs and 137Cs in water samples collected across the Nansen Basin from the Barents Sea slope to the Gakkel Ridge provides tracers with which to characterize both scavenging rates and circulation timescales in this portion of the Arctic Ocean. Large volume water samples (˜ 15001) were filtered in situ to separate particulate (> 0.5 μm) and dissolved Th isotopes and 241Am. Thorium-230 displays increases in both particulate and dissolved activities with depth, with dissolved 230Th greater and particulate 230Th lower in the deep central Nansen Basin than at the Barents Sea slope. Dissolved 228Th activities also are greater relative to 228Ra, in the central basin. Residence times for Th relative to removal from solution onto particles are ˜1 year in surface water, ˜10 years in deep water adjacent to the Barents Sea slope, and ˜20 years in the Eurasian Basin Deep Water. Lead-210 in the central basin deep water also has a residence time of ˜20 years with respect to its removal from the water column. This texture of scavenging is reflected in distributions of the particle-reactive anthropogenic radionuclide 241Am, which shows higher activities relative to Pu in the central Nansen Basin than at the Barents Sea slope. Distributions Of 137Cs show more rapid mixing at the basin margins (Barents Sea slope in the south, Gakkel Ridge in the north) than in the basin interior. Cesium-137 is mixed throughout the water column adjacent to the Barents Sea slope and is present in low but detectable activities in the Eurasian Basin Deep Water in the central basin. At the time of sampling (1987) the surface water at all stations had been labeled with 134Cs released in the 1986 accident at the Chernobyl nuclear power station. In the ˜1 year since the introduction of Chernobyl 134Cs to the Nansen Basin, it had been mixed to depths of ˜800 m at

  19. Role of regression model selection and station distribution on the estimation of oceanic anthropogenic carbon change by eMLR

    NASA Astrophysics Data System (ADS)

    Plancherel, Y.; Rodgers, K. B.; Key, R. M.; Jacobson, A. R.; Sarmiento, J. L.

    2013-07-01

    Quantifying oceanic anthropogenic carbon uptake by monitoring interior dissolved inorganic carbon (DIC) concentrations is complicated by the influence of natural variability. The "eMLR method" aims to address this issue by using empirical regression fits of the data instead of the data themselves, inferring the change in anthropogenic carbon in time by difference between predictions generated by the regressions at each time. The advantages of the method are that it provides in principle a means to filter out natural variability, which theoretically becomes the regression residuals, and a way to deal with sparsely and unevenly distributed data. The degree to which these advantages are realized in practice is unclear, however. The ability of the eMLR method to recover the anthropogenic carbon signal is tested here using a global circulation and biogeochemistry model in which the true signal is known. Results show that regression model selection is particularly important when the observational network changes in time. When the observational network is fixed, the likelihood that co-located systematic misfits between the empirical model and the underlying, yet unknown, true model cancel is greater, improving eMLR results. Changing the observational network modifies how the spatio-temporal variance pattern is captured by the respective datasets, resulting in empirical models that are dynamically or regionally inconsistent, leading to systematic errors. In consequence, the use of regression formulae that change in time to represent systematically best-fit models at all times does not guarantee the best estimates of anthropogenic carbon change if the spatial distributions of the stations emphasize hydrographic features differently in time. Other factors, such as a balanced and representative station coverage, vertical continuity of the regression formulae consistent with the hydrographic context and resiliency of the spatial distribution of the residual field can be used

  20. Relative contribution of lead from anthropogenic sources to the total human lead exposure in the United States. Final report

    SciTech Connect

    Elias, R.W.

    1986-08-01

    The paper evaluates human exposure to lead at a baseline level for persons living in non-urban communities away from stationary or mobile sources of lead, eating typical diets, and engaging in no lead-related occupational or avocational activities. Relative contributions of atmospheric and metallic lead are evaluated for each exposure pathway. For this baseline situation, perhaps 40 to 55% of the total human exposure to lead is of atmospheric origin. Beyond the baseline level, additional exposure factors can be determined for other environments (e.g. urban, occupational, smelter communities) and for certain habits and activities (e.g., pica, smoking, drinking, and various hobbies), with variations for age, sex, or socioeconomic status. Although quantification of these factors is uncertain, they provide guidelines in determining relative exposures under differing environmental conditions. The added exposure factors can also be partitioned into atmospheric, metallic, and pigment lead.

  1. Anthropogenic aerosols and the distribution of past large‐scale precipitation change

    PubMed Central

    2015-01-01

    Abstract The climate response of precipitation to the effects of anthropogenic aerosols is a critical while not yet fully understood aspect in climate science. Results of selected models that participated the Coupled Model Intercomparison Project Phase 5 and the data from the Twentieth Century Reanalysis Project suggest that, throughout the tropics and also in the extratropical Northern Hemisphere, aerosols have largely dominated the distribution of precipitation changes in reference to the preindustrial era in the second half of the last century. Aerosol‐induced cooling has offset some of the warming caused by the greenhouse gases from the tropics to the Arctic and thus formed the gradients of surface temperature anomaly that enable the revealed precipitation change patterns to occur. Improved representation of aerosol‐cloud interaction has been demonstrated as the key factor for models to reproduce consistent distributions of past precipitation change with the reanalysis data. PMID:27134319

  2. Landscape-scale distribution and density of raptor populations wintering in anthropogenic-dominated desert landscapes

    USGS Publications Warehouse

    Duerr, Adam E.; Miller, Tricia A.; Cornell Duerr, Kerri L; Lanzone, Michael J; Fesnock, Amy; Katzner, Todd Eli

    2015-01-01

    Anthropogenic development has great potential to affect fragile desert environments. Large-scale development of renewable energy infrastructure is planned for many desert ecosystems. Development plans should account for anthropogenic effects to distributions and abundance of rare or sensitive wildlife; however, baseline data on abundance and distribution of such wildlife are often lacking. We surveyed for predatory birds in the Sonoran and Mojave Deserts of southern California, USA, in an area designated for protection under the “Desert Renewable Energy Conservation Plan”, to determine how these birds are distributed across the landscape and how this distribution is affected by existing development. We developed species-specific models of resight probability to adjust estimates of abundance and density of each individual common species. Second, we developed combined-species models of resight probability for common and rare species so that we could make use of sparse data on the latter. We determined that many common species, such as red-tailed hawks, loggerhead shrikes, and especially common ravens, are associated with human development and likely subsidized by human activity. Species-specific and combined-species models of resight probability performed similarly, although the former model type provided higher quality information. Comparing abundance estimates with past surveys in the Mojave Desert suggests numbers of predatory birds associated with human development have increased while other sensitive species not associated with development have decreased. This approach gave us information beyond what we would have collected by focusing either on common or rare species, thus it provides a low-cost framework for others conducting surveys in similar desert environments outside of California.

  3. Tracing the anthropogenic lead sources in coastal sediments of SE-pacific (36 degrees Lat. S) using stable lead isotopes.

    PubMed

    Muñoz, Práxedes N V; Garbe-Schönberg, Carl-Dieter; Salamanca, Marco A

    2004-04-01

    This study evaluates the main sources of antropogenic Pb in one of the most industrialized centers of the southern Chilean coast (36 degrees S). Stable lead isotopes ((206)Pb/(207)Pb, (208)Pb/(207)Pb) were used to trace main Pb sources to coastal sediments, considering the suspended particulate matter (SPM) from marine (traps), continental (rivers) and industrial effluents, sediments and leaded gasoline samples. The atmospheric input was evaluated through natural collectors; i.e. Raqui-Tubul salt marsh. Results show that marine samples lie on a trend between industrial effluents ( approximately 1.16, 2.44) and natural sources (1.20, 2.50), not related to gasoline consumption. Salt marsh sediments show comparable isotopic composition to marine samples, suggesting the importance of the atmospheric input in the coastal sediments, not related to the leaded gasoline composition either. The continental input (1.18, 2.48) is highly influenced by precipitation, being difficult to separate both sources (atmosphere and continental runoff), showing also similar isotopic ratio to marine sediments. The signal of industrial emissions is masked with the introduction of Pb with higher isotopic ratios, compared to the values observed in the material collected from traps (SPM approximately 1.19, 2.48). The contribution of more radiogenic Pb by the upwelling is suggested.

  4. Vertical distribution of anthropogenic radionuclides in cores from contaminated floodplains of the Yenisey River.

    PubMed

    Standring, W J F; Brown, J E; Dowdall, M; Korobova, E M; Linnik, V G; Volosov, A G

    2009-12-01

    The Mining and Chemical Industrial Combine, Zheleznogorsk (MCIC, previously known as Krasnoyarsk-26) on the River Yenisey has contaminated the surrounding environment with anthropogenic radionuclides as a result of discharges of radioactive wastes. The purpose of this study was to investigate the vertical distribution of anthropogenic contamination ((137)Cs and plutonium) within floodplain areas at different distances from the discharge point. Sites were chosen that display different characteristics with respect to periodic inundation with river water. Cs-137 activity concentrations were in the range 23-3770 Bq/kg (dry weight, d.w.); Pu-239,240 activity concentrations were in the range <0.01-14.2 Bq/kg (d.w.). Numerous sample cores exhibited sub-surface maxima which may be related to the historical discharges from the MCIC. Possible evidence indicating the deposition of earlier discharges at MCIC in deeper core layers was observed in the (238)Pu:(239,240)Pu activity ratio data: a Pu signal discernible from global fallout could be observed in numerous samples. Cs-137 and Pu-239,240 activity concentrations were correlated with the silt fraction (% by mass <63 microm) though no significant correlation was observed between (grain-size) normalised (137)Cs activity concentrations and distance downstream from the MCIC.

  5. Ecological consequences of human niche construction: Examining long-term anthropogenic shaping of global species distributions

    PubMed Central

    Boivin, Nicole L.; Zeder, Melinda A.; Fuller, Dorian Q.; Crowther, Alison; Larson, Greger; Erlandson, Jon M.; Denham, Tim; Petraglia, Michael D.

    2016-01-01

    The exhibition of increasingly intensive and complex niche construction behaviors through time is a key feature of human evolution, culminating in the advanced capacity for ecosystem engineering exhibited by Homo sapiens. A crucial outcome of such behaviors has been the dramatic reshaping of the global biosphere, a transformation whose early origins are increasingly apparent from cumulative archaeological and paleoecological datasets. Such data suggest that, by the Late Pleistocene, humans had begun to engage in activities that have led to alterations in the distributions of a vast array of species across most, if not all, taxonomic groups. Changes to biodiversity have included extinctions, extirpations, and shifts in species composition, diversity, and community structure. We outline key examples of these changes, highlighting findings from the study of new datasets, like ancient DNA (aDNA), stable isotopes, and microfossils, as well as the application of new statistical and computational methods to datasets that have accumulated significantly in recent decades. We focus on four major phases that witnessed broad anthropogenic alterations to biodiversity—the Late Pleistocene global human expansion, the Neolithic spread of agriculture, the era of island colonization, and the emergence of early urbanized societies and commercial networks. Archaeological evidence documents millennia of anthropogenic transformations that have created novel ecosystems around the world. This record has implications for ecological and evolutionary research, conservation strategies, and the maintenance of ecosystem services, pointing to a significant need for broader cross-disciplinary engagement between archaeology and the biological and environmental sciences. PMID:27274046

  6. Ecological consequences of human niche construction: Examining long-term anthropogenic shaping of global species distributions.

    PubMed

    Boivin, Nicole L; Zeder, Melinda A; Fuller, Dorian Q; Crowther, Alison; Larson, Greger; Erlandson, Jon M; Denham, Tim; Petraglia, Michael D

    2016-06-01

    The exhibition of increasingly intensive and complex niche construction behaviors through time is a key feature of human evolution, culminating in the advanced capacity for ecosystem engineering exhibited by Homo sapiens A crucial outcome of such behaviors has been the dramatic reshaping of the global biosphere, a transformation whose early origins are increasingly apparent from cumulative archaeological and paleoecological datasets. Such data suggest that, by the Late Pleistocene, humans had begun to engage in activities that have led to alterations in the distributions of a vast array of species across most, if not all, taxonomic groups. Changes to biodiversity have included extinctions, extirpations, and shifts in species composition, diversity, and community structure. We outline key examples of these changes, highlighting findings from the study of new datasets, like ancient DNA (aDNA), stable isotopes, and microfossils, as well as the application of new statistical and computational methods to datasets that have accumulated significantly in recent decades. We focus on four major phases that witnessed broad anthropogenic alterations to biodiversity-the Late Pleistocene global human expansion, the Neolithic spread of agriculture, the era of island colonization, and the emergence of early urbanized societies and commercial networks. Archaeological evidence documents millennia of anthropogenic transformations that have created novel ecosystems around the world. This record has implications for ecological and evolutionary research, conservation strategies, and the maintenance of ecosystem services, pointing to a significant need for broader cross-disciplinary engagement between archaeology and the biological and environmental sciences. PMID:27274046

  7. Ecological consequences of human niche construction: Examining long-term anthropogenic shaping of global species distributions.

    PubMed

    Boivin, Nicole L; Zeder, Melinda A; Fuller, Dorian Q; Crowther, Alison; Larson, Greger; Erlandson, Jon M; Denham, Tim; Petraglia, Michael D

    2016-06-01

    The exhibition of increasingly intensive and complex niche construction behaviors through time is a key feature of human evolution, culminating in the advanced capacity for ecosystem engineering exhibited by Homo sapiens A crucial outcome of such behaviors has been the dramatic reshaping of the global biosphere, a transformation whose early origins are increasingly apparent from cumulative archaeological and paleoecological datasets. Such data suggest that, by the Late Pleistocene, humans had begun to engage in activities that have led to alterations in the distributions of a vast array of species across most, if not all, taxonomic groups. Changes to biodiversity have included extinctions, extirpations, and shifts in species composition, diversity, and community structure. We outline key examples of these changes, highlighting findings from the study of new datasets, like ancient DNA (aDNA), stable isotopes, and microfossils, as well as the application of new statistical and computational methods to datasets that have accumulated significantly in recent decades. We focus on four major phases that witnessed broad anthropogenic alterations to biodiversity-the Late Pleistocene global human expansion, the Neolithic spread of agriculture, the era of island colonization, and the emergence of early urbanized societies and commercial networks. Archaeological evidence documents millennia of anthropogenic transformations that have created novel ecosystems around the world. This record has implications for ecological and evolutionary research, conservation strategies, and the maintenance of ecosystem services, pointing to a significant need for broader cross-disciplinary engagement between archaeology and the biological and environmental sciences.

  8. Immobilization of lead in anthropogenic contaminated soils using phosphates with/without oxalic acid.

    PubMed

    Su, Xiaojuan; Zhu, Jun; Fu, Qingling; Zuo, Jichao; Liu, Yonghong; Hu, Hongqing

    2015-02-01

    Understanding the effects of oxalic acid (OA) on the immobilization of Pb(II) in contaminated soils by phosphate materials, has considerable benefits for risk assessment and remediation strategies for the soil. A series of phosphate amendments with/without oxalic acid were applied to two anthropogenic contaminated soils. We investigated the immobilization of Pb(II) by KH2PO4, phosphate rock (PR), activated phosphate rock (APR) and synthetic hydroxyapatite (HAP) at different phosphate:Pb (P:Pb) molar ratios (0, 0.6, 2.0 and 4.0) in the presence/absence of 50 mmol oxalic acid/kg soil, respectively. The effects of treatments were evaluated using single extraction with deionized water or CaCl2, Community Bureau of Reference (BCR) sequential extraction and toxicity characteristic leaching procedure (TCLP) methods. Our results showed that the concentration of water extractable, exchangeable and TCLP-Pb all decreased with incubation time. The concentration of water-extractable Pb after 120 days was reduced by 100% when soils were amended with APR, HAP and HAP+OA, and the TCLP-Pb was <5 mg/L for the red soil at P:Pb molar ratio 4.0. Water-soluble Pb could not be detected and the TCLP-Pb was <5 mg/L at all treatments applied to the yellow-brown soil. BCR results indicated that APR was most effective, although a slight enhancement of water-soluble phosphate was detected at the P:Pb molar ratio 4.0 at the beginning of incubation. Oxalic acid activated phosphates, and so mixing insoluble phosphates with oxalic acid may be a useful strategy to improve their effectiveness in reducing Pb bioavailability.

  9. Uncertainty of spatial distributions of soil magnetic susceptibility in areas of different type of land cover and anthropogenic pressure

    NASA Astrophysics Data System (ADS)

    Zawadzki, Jaroslaw; Fabijańczyk, Piotr

    2016-04-01

    There is still a high interest in the improvement of soil magnetometry procedures that would increase its accuracy. Soil magnetometry is usually used as a fast screening method that is used to assess the degree of soil pollution. As the magnetometric measurements do not provide the exact information about the concentration of elements in soil, it is very important to determine the uncertainty of the spatial distributions of soil magnetic susceptibility. The goal of this study was to analyze and present geostatistical methods of assessing the uncertainty of spatial distribution of soil magnetic susceptibility in areas of different land cover and anthropogenic pressure. In particular, spatial distributions of magnetic susceptibility measured on the soil surface using a MS2D Bartington device were calculated using indicator methods that make it possible to calculate the probability of exceeding the critical levels of soil magnetic susceptibility. Measurements were performed in areas located in the Upper Silesian Industrial Area in Poland, and in Norway. In these areas soil magnetic susceptibility was measured on the soil surface using a MS2D Bartington device. Additionally, soil samples were taken in order to perform chemical measurements that included the determination of a concentration of selected elements. Acknowledgment The research leading to these results has received funding from the Polish-Norwegian Research Programme operated by the National Centre for Research and Development underthe Norwegian Financial Mechanism 2009-2014 in the frame of Project IMPACT - Contract No Pol-Nor/199338/45/2013.

  10. The distributions of one invasive and two native crayfishes in relation to coarse-scale natural and anthropogenic factors

    USGS Publications Warehouse

    Westhoff, J.T.; Rabeni, C.F.; Sowa, S.P.

    2011-01-01

    1. Native crayfishes are often extirpated from portions of their range because of interactions with invasive species, anthropogenic alterations to environmental conditions or a combination of these factors. Our goal was to identify coarse-scale natural and anthropogenic factors related to the current distributions of the invasive crayfish, Orconectes hylas, and two endemic crayfishes, Orconectes peruncus andOrconectes quadruncus in the St. Francis River drainage, Missouri, U.S.A. and to provide wider insights into the potential role of anthropogenic factors in facilitating species displacement. 2. We used classification trees to model coarse-scale natural and anthropogenic environmental factors and their relation to the presence or absence of each species. Model results were then used to predict probability of presence for each species within each stream segment throughout the entire St. Francis River drainage. 3. Factors related to geology and soils were the best predictors of species distributions. A dichotomy of these factors explained much of the discrete distributions of the two native species. Agricultural-related factors were identified as the most influential anthropogenic activity related to species distributions. All associations between the invasive species and anthropogenic factors were negative which suggested the invader was not likely to establish in heavily impacted areas. Overall, our models had high correct classification rates, and we were able to reliably predict the presence of the invader in the invaded drainage. 4. Given the negative associations of the invader with anthropogenic alterations at a coarse spatial scale, we believe other mechanisms are likely to be responsible for the widespread displacement of the two native species. These findings can be used to assist in conservation activities such as creation of refugia for native species and may direct future research to identify the mechanism(s) of species displacement.

  11. Spatial distribution of dissolved cadmium in the Jiulong river-estuary system: Relevance of anthropogenic perturbation

    NASA Astrophysics Data System (ADS)

    Wang, Deli; Yang, Xiqian; Zhai, Weidong; Li, Yan; Hong, Huasheng

    2015-12-01

    This study first examined the spatial distribution of dissolved cadmium (Cd) along with other hydrochemical parameters in a large subtropical river estuary system (the Jiulong River-Estuary, China) between 2008 and 2010, aiming to evaluate the impacts of the recently increasing anthropogenic perturbation in natural waters. The results showed that dissolved Cd was variable in the watershed with sporadically high concentrations (>0.6 nmol L-1). The significantly positive correlation of dissolved Cd with phosphate in the watershed (May 2008: dissolved Cd=0.22*P+0.0062, r=0.64, p<0.05) indicated that dissolved Cd levels have been elevated along with P by the increasing agricultural discharges and/or sewage effluents. The estuary was characterized with decreased levels of dissolved Cd in the highly turbid upper part (salinity: <5; dissolved Cd: <0.1 nmol L-1; Total Suspended Matter: 100-300 mg/L), and a mid-salinity maximum of dissolved Cd in the middle part, which were higher in Summer high river discharge period (0.40-0.54 nmol L-1) than in Fall low river discharge period (0.25-0.35 nmol L-1). Dissolved Cd generally decreased outwards in the lower estuary and nearby coastal waters as mixed with the low Cd-content seawater offshore (dissolved Cd= -0.025*Salinity+0.96, r=0.60, p<0.05). In particular, an enhancement of dissolved Cd (by ~0.2 nmol L-1) was observed in the lower estuary and estuarine plume zone as a result of sewage discharges nearby and/or Cd-enriched submarine groundwater discharges. Summarily, our exemplary study provides clear evidence that China's natural waters are currently subject to local perturbation due to the recently increasing anthropogenic activities.

  12. A new approach for quantifying cumulative, anthropogenic, atmospheric lead deposition using peat cores from bogs: Pb in eight Swiss peat bog profiles.

    PubMed

    Shotyk, W; Blaser, P; Grünig, A; Cheburkin, A K

    2000-04-17

    Peat cores taken from eight Swiss peatlands were used to calculate inventories of anthropogenic Pb using either Sc or Zr to quantify Pb derived from rock weathering. The shapes of the Pb/Sc and Pb/Zr profiles suggest that Pb was supplied exclusively by atmospheric deposition at all sites. At one of the sites (Etang de la Gruère), anthropogenic Pb was calculated using both Sc and Zr as the conservative reference element. Lithogenic Pb determined using Sc was twice that obtained using Zr, possibly because Zr resides only in zircons which are dense compared to pyroxene and amphibole which are the main Sc-bearing phases in the earth's crust. However, the inventory of 'natural' Pb (supplied almost entirely by soil dust) is dwarfed by the anthropogenic inventory such that anthropogenic Pb calculated using Sc and Zr agree to within 5%. The total amount of anthropogenic Pb accumulated in the bogs was calculated by simply adding the mass of anthropogenic Pb for each peat slice over the length of each core. Cumulative, anthropogenic Pb calculated in this way ranged from 1.0 to 9.7 g/m2 and showed pronounced regional differences: the site south of the Alps (Gola di Lago in Canton Ticino) with direct exposure to the heavily industrialized region of northern Italy received nearly 10 times more anthropogenic Pb as the sites in more remote alpine regions (Schöpfenwaldmoor in Canton Berne, and Mauntschas in Canton Grisons). The approach used here to calculate cumulative, anthropogenic, atmospheric Pb (CAAPb) is simple and robust, independent of the chronology of Pb deposition, and makes no assumptions about the immobility of Pb within the peat profile. Given the worldwide distribution of peat bogs, it should be possible to undertake continental and global inventories of atmospheric metal deposition, for both the natural and anthropogenic components of most trace metals of environmental interest.

  13. Movement responses of caribou to human-induced habitat edges lead to their aggregation near anthropogenic features.

    PubMed

    Fortin, Daniel; Buono, Pietro-Luciano; Fortin, André; Courbin, Nicolas; Tye Gingras, Christian; Moorcroft, Paul R; Courtois, Réhaume; Dussault, Claude

    2013-06-01

    The assessment of disturbance effects on wildlife and resulting mitigation efforts are founded on edge-effect theory. According to the classical view, the abundance of animals affected by human disturbance should increase monotonically with distance from disturbed areas to reach a maximum at remote locations. Here we show that distance-dependent movement taxis can skew abundance distributions toward disturbed areas. We develop an advection-diffusion model based on basic movement behavior commonly observed in animal populations and parameterize the model from observations on radio-collared caribou in a boreal ecosystem. The model predicts maximum abundance at 3.7 km from cutovers and roads. Consistently, aerial surveys conducted over 161,920 km(2) showed that the relative probability of caribou occurrence displays nonmonotonic changes with the distance to anthropogenic features, with a peak occurring at 4.5 km away from these features. This aggregation near disturbed areas thus provides the predators of this top-down-controlled, threatened herbivore species with specific locations to concentrate their search. The edge-effect theory developed here thus predicts that human activities should alter animal distribution and food web properties differently than anticipated from the current paradigm. Consideration of such nonmonotonic response to habitat edges may become essential to successful wildlife conservation. PMID:23669544

  14. Movement responses of caribou to human-induced habitat edges lead to their aggregation near anthropogenic features.

    PubMed

    Fortin, Daniel; Buono, Pietro-Luciano; Fortin, André; Courbin, Nicolas; Tye Gingras, Christian; Moorcroft, Paul R; Courtois, Réhaume; Dussault, Claude

    2013-06-01

    The assessment of disturbance effects on wildlife and resulting mitigation efforts are founded on edge-effect theory. According to the classical view, the abundance of animals affected by human disturbance should increase monotonically with distance from disturbed areas to reach a maximum at remote locations. Here we show that distance-dependent movement taxis can skew abundance distributions toward disturbed areas. We develop an advection-diffusion model based on basic movement behavior commonly observed in animal populations and parameterize the model from observations on radio-collared caribou in a boreal ecosystem. The model predicts maximum abundance at 3.7 km from cutovers and roads. Consistently, aerial surveys conducted over 161,920 km(2) showed that the relative probability of caribou occurrence displays nonmonotonic changes with the distance to anthropogenic features, with a peak occurring at 4.5 km away from these features. This aggregation near disturbed areas thus provides the predators of this top-down-controlled, threatened herbivore species with specific locations to concentrate their search. The edge-effect theory developed here thus predicts that human activities should alter animal distribution and food web properties differently than anticipated from the current paradigm. Consideration of such nonmonotonic response to habitat edges may become essential to successful wildlife conservation.

  15. [Temporal and spatial distribution of anthropogenic ammonia emissions in China: 1994-2006].

    PubMed

    Dong, Wen-xuan; Xing, Jia; Wang, Shu-xiao

    2010-07-01

    Ammonia has both direct and indirect impacts on important environmental issues including acid deposition, regional fine particles and eutrophication. Estimation of anthropogenic ammonia emissions will provide valuable information for the pollution control of acid deposition and regional fine particle. Based on the provincial activity data on N-fertilizer application, livestock farming, N-fertilizer production and populations, this paper uses emission factor method to estimate China's atmospheric ammonia emissions, analyzes its historical trends and presents its geographical distributions from year 1994 to 2006. The national total atmospheric ammonia emissions are estimated to be 11.06 million tons (Mt) in 1994, which increase quickly to 16.07 Mt in 2006. Emissions from livestock farming, N-fertilizer application, N-fertilizer production and human excreta have increased from 4.47 Mt, 5.94 Mt, 0.09 Mt, and 0.59 Mt in 1994 to 6.61 Mt, 8.68 Mt, 0.14 Mt, 0.65 Mt respectively in 2006. Livestock farming and N-fertilizer application are the most important ammonia emission sources, which contributed 40.79 and 55.53 percent of total emissions respectively in 2006. In 2006, the average ammonia emission intensity is 1.67 t x km(-2) but there are large variations among atmospheric ammonia emissions from each province. Emissions from provinces including Henan, Shandong, Hebei, Sichuan and Jiangsu accounted for 40.82 percent of national emissions. PMID:20825010

  16. Distribution of lead in single atmospheric particles

    NASA Astrophysics Data System (ADS)

    Murphy, D. M.; Hudson, P. K.; Cziczo, D. J.; Gallavardin, S.; Froyd, K. D.; Johnston, M. V.; Middlebrook, A. M.; Reinard, M. S.; Thomson, D. S.; Thornberry, T.; Wexler, A. S.

    2007-03-01

    Three independent single particle mass spectrometers measured Pb in individual aerosol particles. These data provide unprecedented sensitivity and statistical significance for the measurement of Pb in single particles. This paper explores the reasons for the frequency of Pb in fine particles now that most gasoline is unleaded. Trace amounts of Pb were found in 5 to 25% of 250 to 3000 nm diameter particles sampled by both aircraft and surface instruments in the eastern and western United States. Over 5% of particles at a mountain site in Switzerland contained Pb. Particles smaller than 100 nm with high Pb content were also observed by an instrument that was only operated in urban areas. Lead was found on all types of particles, including Pb present on biomass burning particles from remote fires. Less common particles with high Pb contents contributed a majority of the total amount of Pb. Single particles with high Pb content often also contained alkali metals, Zn, Cu, Sn, As, and Sb. The association of Pb with Zn and other metals is also found in IMPROVE network filter data from surface sites. Sources of airborne Pb in the United States are reviewed for consistency with these data. The frequent appearance of trace Pb is consistent with widespread emissions of fine Pb particles from combustion sources followed by coagulation with larger particles during long-range transport. Industrial sources that directly emit Pb-rich particles also contribute to the observations. Clean regions of the western United States show some transport of Pb from Asia but most Pb over the United States comes from North American sources. Resuspension of Pb from soil contaminated by the years of leaded gasoline was not directly apparent.

  17. Distribution of lead in single atmospheric particles

    NASA Astrophysics Data System (ADS)

    Murphy, D. M.; Hudson, P. K.; Cziczo, D. J.; Gallavardin, S.; Froyd, K. D.; Johnston, M. V.; Middlebrook, A. M.; Reinard, M. S.; Thomson, D. S.; Thornberry, T.; Wexler, A. S.

    2007-06-01

    Three independent single particle mass spectrometers measured Pb in individual aerosol particles. These data provide unprecedented sensitivity and statistical significance for the measurement of Pb in single particles. This paper explores the reasons for the frequency of Pb in fine particles now that most gasoline is unleaded. Trace amounts of Pb were found in 5 to 25% of 250 to 3000 nm diameter particles sampled by both aircraft and surface instruments in the eastern and western United States. Over 5% of particles at a mountain site in Switzerland contained Pb. Particles smaller than 100 nm with high Pb content were also observed by an instrument that was only operated in urban areas. Lead was found on all types of particles, including Pb present on biomass burning particles from remote fires. Less common particles with high Pb contents contributed a majority of the total amount of Pb. Single particles with high Pb content often also contained alkali metals, Zn, Cu, Sn, As, and Sb. The association of Pb with Zn and other metals is also found in IMPROVE network filter data from surface sites. Sources of airborne Pb in the United States are reviewed for consistency with these data. The frequent appearance of trace Pb is consistent with widespread emissions of fine Pb particles from combustion sources followed by coagulation with larger particles during long-range transport. Industrial sources that directly emit Pb-rich particles also contribute to the observations. Clean regions of the western United States show some transport of Pb from Asia but most Pb over the United States comes from North American sources. Resuspension of Pb from soil contaminated by the years of leaded gasoline was not directly apparent.

  18. Sensitivity of air pollution simulations with LOTOS-EUROS to the temporal distribution of anthropogenic emissions

    NASA Astrophysics Data System (ADS)

    Mues, A.; Kuenen, J.; Hendriks, C.; Manders, A.; Segers, A.; Scholz, Y.; Hueglin, C.; Builtjes, P.; Schaap, M.

    2014-01-01

    and 2 profiles were found for SO2. When using all new time profiles simultaneously in one simulation, the daily average correlation coefficient increased by 0.05 (NO2), 0.07 (SO2) and 0.03 (PM10) at urban background stations in Germany. This exercise showed that to improve the performance of a CTM, a better representation of the distribution of anthropogenic emission in time is recommendable. This can be done by developing a dynamical emission model that takes into account regional specific factors and meteorology.

  19. Sensitivity of air pollution simulations with LOTOS-EUROS to temporal distribution of anthropogenic emissions

    NASA Astrophysics Data System (ADS)

    Mues, A.; Kuenen, J.; Hendriks, C.; Manders, A.; Segers, A.; Scholz, Y.; Hueglin, C.; Builtjes, P.; Schaap, M.

    2013-07-01

    .05 (NO2), 0.07 (SO2) and 0.03 (PM10) at urban background stations in Germany. This exercise showed that to improve the performance of a CTM a better representation of the distribution of anthropogenic emission in time is recommendable. This can be done by developing a dynamical emission model which takes into account regional specific factors and meteorology.

  20. Geomorphic changes leading to natural desertification versus anthropogenic land conservation in an arid environment, the Negev Highlands, Israel

    NASA Astrophysics Data System (ADS)

    Avni, Yoav; Porat, Naomi; Plakht, Joseph; Avni, Gideon

    2006-12-01

    The Negev Highlands in southern Israel are currently under an erosive regime causing degradation of soil and vegetation; a process which has often been attributed to land mismanagement and overgrazing caused by the local Bedouin population. To estimate the anthropogenic role in the erosional processes in the Negev Highlands, two similar drainage basins were selected and studied, one undisturbed with almost no human impact and the other with intensive human modification including the establishment of Roman to Early Islamic agriculture. Field observations and luminescence dating indicate that during the Late Pleistocene glacial period (OIS 4 and 3) deposition of fluvio-loess sediments, with minor erosion cycles, occurred in the Negev Highlands. Severe erosion started during OIS 2 and continued into the Holocene. As the climate shifted during the termination of the Pleistocene to the present interglacial phase, higher rain intensity generated the incision of gullies and channels into the fine-grained alluvial sediments of the previous phase, causing extended soil erosion and reducing the natural biomass and the agricultural potential. Establishment of runoff-harvesting farms in the 3rd century interrupted the Holocene natural erosion and gully incision, and led to the redeposition of up to 3.5 m of fine alluvial loess sediments originating from Late Pleistocene loess sections. This accumulation is not related to any late-Holocene pluvial climatic phase and is solely the result of farming. We conclude that since the end of the Pleistocene a dynamic change in the soil/rock ratio related to the long-term process of adjustment of the geomorphologic system to the Holocene climate has been taking place within the drainage basins in the Negev Highlands. The fluvio-loess sediments deposited in the region during OIS 4 and 3 have been eroding since the latest Pleistocene throughout the Holocene. This process causes degradation of the biomass and agricultural potential and leads

  1. A 500 year sediment lake record of anthropogenic and natural inputs to Windermere (English Lake District) using double-spike lead isotopes, radiochronology, and sediment microanalysis.

    PubMed

    Miller, Helen; Croudace, Ian W; Bull, Jonathan M; Cotterill, Carol J; Dix, Justin K; Taylor, Rex N

    2014-07-01

    A high-resolution record of pollution is preserved in recent sediments from Windermere, the largest lake in the English Lake District. Data derived from X-ray core scanning (validated against wavelength dispersive X-ray fluorescence), radiochronological techniques ((210)Pb and (137)Cs) and ultrahigh precision, double-spike mass spectrometry for lead isotopes are combined to decipher the anthropogenic inputs to the lake. The sediment record suggests that while most element concentrations have been stable, there has been a significant increase in lead, zinc, and copper concentrations since the 1930s. Lead isotope down-core variations identify three major contributory sources of anthropogenic (industrial) lead, comprising gasoline lead, coal combustion lead (most likely source is coal-fired steam ships), and lead derived from Carboniferous Pb-Zn mineralization (mining activities). Periods of metal workings do not correlate with peaks in heavy metals due to the trapping efficiency of up-system lakes in the catchment. Heavy metal increases could be due to flood-induced metal inwash after the cessation of mining and the weathering of bedrock in the catchment. The combination of sediment analysis techniques used provides new insights into the pollutant depositional history of Windermere and could be similarly applied to other lake systems to determine the timing and scale of anthropogenic inputs.

  2. Megafauna of vulnerable marine ecosystems in French mediterranean submarine canyons: Spatial distribution and anthropogenic impacts

    NASA Astrophysics Data System (ADS)

    Fabri, M.-C.; Pedel, L.; Beuck, L.; Galgani, F.; Hebbeln, D.; Freiwald, A.

    2014-06-01

    Vulnerable Marine Ecosystems (VME) in the deep Mediterranean Sea have been identified by the General Fisheries Commission for the Mediterranean as consisting of communities of Scleractinia (Lophelia pertusa and Madrepora oculata), Pennatulacea (Funiculina quadrangularis) and Alcyonacea (Isidella elongata). This paper deals with video data recorded in the heads of French Mediterranean canyons. Quantitative observations were extracted from 101 video films recorded during the MEDSEACAN cruise in 2009 (Aamp/Comex). Qualitative information was extracted from four other cruises (two Marum/Comex cruises in 2009 and 2011 and two Ifremer cruises in 1995 and 2010) to support the previous observations in the Cassidaigne and Lacaze-Duthiers canyons. All the species, fishing impacts and litter recognized in the video films recorded from 180 to 700 m depth were mapped using GIS. The abundances and distributions of benthic fishing resources (marketable fishes, Aristeidae, Octopodidae), Vulnerable Marine Species, trawling scars and litter of 17 canyons were calculated and compared, as was the open slope between the Stoechades and Toulon canyons. Funiculina quadrangularis was rarely observed, being confined for the most part to the Marti canyon and, I. elongata was abundant in three canyons (Bourcart, Marti, Petit-Rhône). These two cnidarians were encountered in relatively low abundances, and it may be that they have been swept away by repeated trawling. The Lacaze-Duthiers and Cassidaigne canyons comprised the highest densities and largest colony sizes of scleractinian cold-water corals, whose distribution was mapped in detail. These colonies were often seen to be entangled in fishing lines. The alcyonacean Callogorgia verticillata was observed to be highly abundant in the Bourcart canyon and less abundant in several other canyons. This alcyonacean was also severely affected by bottom fishing gears and is proposed as a Vulnerable Marine Species. Our studies on anthropogenic

  3. Seasonal variations in the sources of natural and anthropogenic lead deposited at the East Rongbuk Glacier in the high-altitude Himalayas.

    PubMed

    Burn-Nunes, Laurie; Vallelonga, Paul; Lee, Khanghyun; Hong, Sungmin; Burton, Graeme; Hou, Shugui; Moy, Andrew; Edwards, Ross; Loss, Robert; Rosman, Kevin

    2014-07-15

    Lead (Pb) isotopic compositions and concentrations, and barium (Ba) and indium (In) concentrations have been analysed at sub-annual resolution in three sections from a <110 m ice core dated to the 18th and 20th centuries, as well as snow pit samples dated to 2004/2005, recovered from the East Rongbuk Glacier in the high-altitude Himalayas. Ice core sections indicate that atmospheric chemistry prior to ~1,953 was controlled by mineral dust inputs, with no discernible volcanic or anthropogenic contributions. Eighteenth century monsoon ice core chemistry is indicative of dominant contributions from local Himalayan sources; non-monsoon ice core chemistry is linked to contributions from local (Himalayan), regional (Indian/Thar Desert) and long-range (North Africa, Central Asia) sources. Twentieth century monsoon and non-monsoon ice core data demonstrate similar seasonal sources of mineral dust, however with a transition to less-radiogenic isotopic signatures that suggests local and regional climate/environmental change. The snow pit record demonstrates natural and anthropogenic contributions during both seasons, with increased anthropogenic influence during non-monsoon times. Monsoon anthropogenic inputs are most likely sourced to South/South-East Asia and/or India, whereas non-monsoon anthropogenic inputs are most likely sourced to India and Central Asia. PMID:24797737

  4. Anthropogenic carbon estimates in the Weddell Sea using an optimized CFC based transit time distribution approach

    NASA Astrophysics Data System (ADS)

    Huhn, Oliver; Hauck, Judith; Hoppema, Mario; Rhein, Monika; Roether, Wolfgang

    2010-05-01

    We use a 20 year time series of chlorofluorocarbon (CFC) observations along the Prime Meridian to determine the temporal evolution of anthropogenic carbon (Cant) in the two deep boundary currents which enter the Weddell Basin in the south and leave it in the north. The Cant is inferred from transit time distributions (TTDs), with parameters (mean transit time and dispersion) adjusted to the observed mean CFC histories in these recently ventilated deep boundary currents. We optimize that "classic" TTD approach by accounting for water exchange of the boundary currents with an old but not CFC and Cant free interior reservoir. This reservoir in turn, is replenished by the boundary currents, which we parameterize as first order mixing. Furthermore, we account for the time-dependence of the CFC and Cant source water saturation. A conceptual model of an ideal saturated mixed layer and exchange with adjacent water is adjusted to observed CFC saturations in the source regions. The time-dependence for the CFC saturation appears to be much weaker than for Cant. We find a mean transit time of 14 years and an advection/dispersion ratio of 5 for the deep southern boundary current. For the northern boundary current we find a mean transit time of 8 years and a much advection/dispersion ratio of 140. The fractions directly supplied by the boundary currents are in both cases in the order of 10%, while 90% are admixed from the interior reservoirs, which are replenished with a renewal time of about 14 years. We determine Cant ~ 11 umol/kg (reference year 2006) in the deep water entering the Weddell Sea in the south (~2.1 Sv), and 12 umol/kg for the deep water leaving the Weddell Sea in the north (~2.7 Sv). These Cant estimates are, however, upper limits, considering that the Cant source water saturation is likely to be lower than that for the CFCs. Comparison with Cant intrusion estimates based on extended multiple linear regression (using potential temperature, salinity, oxygen, and

  5. Distribution of polychaete assemblage in relation to natural environmental variation and anthropogenic stress

    NASA Astrophysics Data System (ADS)

    Zan, Xiaoxiao; Zhang, Chongliang; Xu, Binduo; Xue, Ying; Ren, Yiping

    2015-08-01

    Polychaete are diverse species of the soft-bottom community, and are often used as indicators in environment monitoring programs. However, the effects of anthropogenic activities and natural environmental variation on polychaete assemblage are rarely addressed. The goals of this study are to identify the effects of natural environmental variation and anthropogenic stress on polychaete assemblage, and to explore the relationship between the polychaete assemblage structure and anthropogenic stress without considering the natural environmental variation. Based on the data collected from the surveys conducted in the tidal flat of Jiaozhou Bay, the relationship between polychaete assemblage structure and environmental variables was determined using multivariate statistical methods including hierarchical cluster analysis, multidimensional scaling (MDS) and canonical correspondence analysis (CCA). The results showed that the polychaete assemblage was dominated by two species, Amphictene japonica and Heteromastus filiformis, and could be divided into two subgroups characterized by high and low species abundance. CCA illustrated that the natural environmental variables including water temperature and the distance from coast had primary effects on the polychaete assemblage structure; while stress of contaminants, such as As and Hg, had the secondary influences; and stress from the aquacultured species, mainly Ruditapes philippinarum, had a limited effect. Colinearity between the natural environmental variables and anthropogenic stress variables caused a critical divergence in the interpretation of CCA results, which highlighted the risk of a lack of information in environment assessment. Glycinde gurjanovae, Sternaspis scutata and Eulalia bilineata may serve as the `contamination indicators', which need to be confirmed in future studies.

  6. Distribution of biologic, anthropogenic, and volcanic constituents as a proxy for sediment transport in the San Francisco Bay Coastal System

    USGS Publications Warehouse

    McGann, Mary; Erikson, Li H.; Wan, Elmira; Powell, Charles L.; Maddocks, Rosalie F.

    2013-01-01

    Although conventional sediment parameters (mean grain size, sorting, and skewness) and provenance have typically been used to infer sediment transport pathways, most freshwater, brackish, and marine environments are also characterized by abundant sediment constituents of biological, and possibly anthropogenic and volcanic, origin that can provide additional insight into local sedimentary processes. The biota will be spatially distributed according to its response to environmental parameters such as water temperature, salinity, dissolved oxygen, organic carbon content, grain size, and intensity of currents and tidal flow, whereas the presence of anthropogenic and volcanic constituents will reflect proximity to source areas and whether they are fluvially- or aerially-transported. Because each of these constituents have a unique environmental signature, they are a more precise proxy for that source area than the conventional sedimentary process indicators. This San Francisco Bay Coastal System study demonstrates that by applying a multi-proxy approach, the primary sites of sediment transport can be identified. Many of these sites are far from where the constituents originated, showing that sediment transport is widespread in the region. Although not often used, identifying and interpreting the distribution of naturally-occurring and allochthonous biologic, anthropogenic, and volcanic sediment constituents is a powerful tool to aid in the investigation of sediment transport pathways in other coastal systems.

  7. [Characterization of lead size distributions with different process in lead-zinc smelter].

    PubMed

    Liang, Jun-Ning; Li, Wen-Hui; Ge, Yi; Chen, Jie; Song, Li-Na; Liu, Jie

    2014-08-01

    Using a cascade impactor (Andersen Series NVA-800), the size-segregated atmospheric particulates were collected daily and characters of lead contents and size distribution in the particles were analyzed from melting preparation, blast furnace smelting and lead-cast processes within a lead-zinc smelter in Shaanxi province. The results showed that emissions of particulate matter were different in different processes, in which the emissions of blast furnace smelting process was 402.83 mg x h(-1), while melting preparation were 182.71 mg x h(-1) and 100.03 mg x h(-1) in lead-cast processes. Lead contents in different sizes of particles varied in different processes. The mass fraction of lead were 111.54 mg x kg(-1), 68.54 mg x kg(-1) and 10.5 mg x kg(-1) in melting preparation, blast furnace smelting and lead-cast respectively. For lead's size distribution, the melting preparation and blast furnace smelting were mainly concentrated in the coarse particles, and the lead proportion in coarse and fine particles was approximately in lead-cast processes. The proportions of lead in coarse particles were 43.42% and 47.48% in melting preparation and blast furnace smelting process respectively, while the proportion of lead in coarse and fine particles was 37.14% and was 45.72% in lead-cast processes. There had peaks in both coarse and fine particles of melting preparation and lead-cast process, but the lead peak appeared only in the coarse particles of blast furnace smelting. It also indicated that the lead's cumulative frequencies of all processes were conforming to lognormal distribution.

  8. Distribution of lead in human bone: 2. Proton microprobe measurements

    SciTech Connect

    Schidlovsky, G.; Jones, K.W. ); Burger, D.E.; Milder, F.L. ); Hu, H. )

    1989-01-01

    Little is known about the distribution of lead in the human tibia on a microscopic scale. The radial distribution of lead in a 2-mm thick section of the human femur has been measured; it was observed that the concentration peaked in a region close to the periosteal and endosteal surfaces. The distribution in the interior of the bone was relatively uniform with the exception of a peak located about 1.8 mm from the periphery along a straight radial scan from periosteum to endosteum. Lindh also mapped the distribution of lead over a single osteon and showed that the concentration was highest at the edges. We have investigated the radial distribution of lead in the human tibia. Our motivation was to obtain data that can be used to understand the biological mechanisms for deposition of lead in bone and for use in the interpretation of in-vivo bone x-ray fluorescence (XRF) measurements of lead concentration. This paper presents the results of proton microprobe line scans of several tibial sections from periosteum to endosteum with spatial resolutions from less than 100 micrometers to about 1000 micrometers. The results are complementary to those reported in a companion paper. 3 refs.

  9. Vertical distribution and flows of lead and natural radionuclides in the atmosphere.

    PubMed

    Kownacka, L; Jaworowski, Z; Suplinska, M

    1990-02-01

    Vertical distributions of radium-226, lead-210, uranium and stable lead were observed in the troposphere and lower stratosphere over Poland at several altitudes between 0 and 15 km in the period 1973-1987. Greatly increased concentrations of stable lead and radium-226 were observed at all altitudes for several years after the Fuego volcano eruption in 1974, and also after the Nevado del Ruiz eruption in 1985. The volcanic eruptions in 1980-1982 contributed to the radium-226 and uranium levels at the higher altitudes. The annual flows of radium-226, lead-210, uranium and stable lead into the global atmosphere, estimated from their long-term average contents in the 0-15 km air layer, are 2.3 x 10(14) Bq, 8.4 x 10(15) Bq, 8.3 x 10(9) g and 3.7 x 10(12) g, respectively. These estimates are similar to those based on concentrations of these nuclides in widely dispersed glaciers in both hemispheres, and on radon-222 exhalation measurements. However, they are higher than estimates based on particulate emissions. The anthropogenic contribution to the total flow of radium-226 into the global atmosphere is approximately 3.7%, for lead-210 0.25%, uranium 17% and stable lead 9.7%.

  10. Aerosol size distribution and radiative forcing response to anthropogenically driven historical changes in biogenic secondary organic aerosol formation

    NASA Astrophysics Data System (ADS)

    D'Andrea, S. D.; Acosta Navarro, J. C.; Farina, S. C.; Scott, C. E.; Rap, A.; Farmer, D. K.; Spracklen, D. V.; Riipinen, I.; Pierce, J. R.

    2015-03-01

    Emissions of biogenic volatile organic compounds (BVOCs) have changed in the past millennium due to changes in land use, temperature, and CO2 concentrations. Recent reconstructions of BVOC emissions have predicted that global isoprene emissions have decreased, while monoterpene and sesquiterpene emissions have increased; however, all three show regional variability due to competition between the various influencing factors. In this work, we use two modeled estimates of BVOC emissions from the years 1000 to 2000 to test the effect of anthropogenic changes to BVOC emissions on secondary organic aerosol (SOA) formation, global aerosol size distributions, and radiative effects using the GEOS-Chem-TOMAS (Goddard Earth Observing System; TwO-Moment Aerosol Sectional) global aerosol microphysics model. With anthropogenic emissions (e.g., SO2, NOx, primary aerosols) turned off and BVOC emissions changed from year 1000 to year 2000 values, decreases in the number concentration of particles of size Dp > 80 nm (N80) of > 25% in year 2000 relative to year 1000 were predicted in regions with extensive land-use changes since year 1000 which led to regional increases in the combined aerosol radiative effect (direct and indirect) of > 0.5 W m-2 in these regions. We test the sensitivity of our results to BVOC emissions inventory, SOA yields, and the presence of anthropogenic emissions; however, the qualitative response of the model to historic BVOC changes remains the same in all cases. Accounting for these uncertainties, we estimate millennial changes in BVOC emissions cause a global mean direct effect of between +0.022 and +0.163 W m-2 and the global mean cloud-albedo aerosol indirect effect of between -0.008 and -0.056 W m-2. This change in aerosols, and the associated radiative forcing, could be a largely overlooked and important anthropogenic aerosol effect on regional climates.

  11. Aerosol size distribution and radiative forcing response to anthropogenically driven historical changes in biogenic secondary organic aerosol formation

    NASA Astrophysics Data System (ADS)

    D'Andrea, S. D.; Acosta Navarro, J. C.; Farina, S. C.; Scott, C. E.; Rap, A.; Farmer, D. K.; Spracklen, D. V.; Riipinen, I.; Pierce, J. R.

    2014-10-01

    Emissions of biogenic volatile organic compounds (BVOC) have changed in the past millennium due to changes in land use, temperature and CO2 concentrations. Recent model reconstructions of BVOC emissions over the past millennium predicted changes in dominant secondary organic aerosol (SOA) producing BVOC classes (isoprene, monoterpenes and sesquiterpenes). The reconstructions predicted that global isoprene emissions have decreased (land-use changes to crop/grazing land dominate the reduction), while monoterpene and sesquiterpene emissions have increased (temperature increases dominate the increases); however, all three show regional variability due to competition between the various influencing factors. These BVOC changes have largely been anthropogenic in nature, and land-use change was shown to have the most dramatic effect by decreasing isoprene emissions. In this work, we use two modeled estimates of BVOC emissions from the years 1000 to 2000 to test the effect of anthropogenic changes to BVOC emissions on SOA formation, global aerosol size distributions, and radiative effects using the GEOS-Chem-TOMAS global aerosol microphysics model. With anthropogenic emissions (e.g. SO2, NOx, primary aerosols) held at present day values and BVOC emissions changed from year 1000 to year 2000 values, decreases in the number concentration of particles of size Dp > 80 nm (N80) of >25% in year 2000 relative to year 1000 were predicted in regions with extensive land-use changes since year 1000 which led to regional increases in direct plus indirect aerosol radiative effect of >0.5 W m-2 in these regions. We test the sensitivity of our results to BVOC emissions inventory, SOA yields and the presence of anthropogenic emissions; however, the qualitative response of the model to historic BVOC changes remains the same in all cases. Accounting for these uncertainties, we estimate millennial changes in BVOC emissions cause a global mean direct effect of between +0.022 and +0.163 W m-2

  12. Natural and anthropogenic influences on the distribution of the threatened Neosho madtom in a midwestern warmwater stream

    USGS Publications Warehouse

    Wildhaber, M.L.; Allert, A.L.; Schmitt, C.J.; Tabor, V.M.; Mulhern, D.; Powell, K.L.; Sowa, S.P.

    2000-01-01

    We attempted to discern the contributions of physical habitat, water chemistry, nutrients, and contaminants from historic lead-zinc mining activities on the riffle-dwelling benthic fish community of the Spring River, a midwestern warmwater stream that originates in Missouri and flows into Kansas and Oklahoma. The Spring River has a fish community that includes the Neosho madtom Noturus placidus, a species federally listed as threatened. Although anthropogenic factors such as contaminants limited populations and densities of fishes, an integrated assessment of natural and anthropogenic factors was necessary to effectively estimate the influence of the latter. Fish populations in the Spring River, especially Neosho madtoms, seem to be limited by the presence of cadmium, lead, and zinc in water and in benthic invertebrate food sources and by physical habitat. The population density and community structure of fish in the Spring River also seem to be related to water chemistry and nutrients. Concurrently, diminished food availability may be limiting fish populations at some sites where Neosho madtoms are not found. Many of the natural factors that may be limiting Neosho madtom and other riffle-dwelling fish populations in the Spring River probably are characteristic of the physiographic region drained by the upper reach and many of the tributaries of the Spring River. Our results indicate that competition between the Neosho madtom and other species within the riffle-dwelling fish community is an unlikely cause of Neosho madtom population limitation in the Spring River.

  13. Distribution of natural and anthropogenic radionuclides in heavy rainfall areas in Jordan.

    PubMed

    Ababneh, Anas M; Almomani, Ali M; Alyassin, Abdalmajeid M; Ababneh, Zaid Q

    2012-06-01

    Soil is the main reservoir of both natural and artificial radionuclides, which are transported to the human body through the food chain. Thus, assessment of the level of radioactivity in soil is of crucial importance. Artificial radionuclide concentrations in soil depend heavily on rainfall and weather conditions. In this study, the soil of the Ras Muneef area, which has the highest rainfall in Jordan, was investigated for its natural and anthropogenic radioactive content. The area was divided into four sectors and in each sector three locations were investigated depending on the land use: undisturbed, cultivated or residential. The depth profile of (137)Cs was investigated and found to depend on the land use. In the undisturbed soils, two types of depth profiles were identified: Gaussian and exponentially decreasing. The annual effective dose was found to range from 19.4 to 72.6 μSv, which falls within the worldwide ranges.

  14. Assessing anthropogenic impact on boreal lakes with historical fish species distribution data and hydrogeochemical modeling

    PubMed Central

    Valinia, Salar; Englund, Göran; Moldan, Filip; Futter, Martyn N; Köhler, Stephan J; Bishop, Kevin; Fölster, Jens

    2014-01-01

    Quantifying the effects of human activity on the natural environment is dependent on credible estimates of reference conditions to define the state of the environment before the onset of adverse human impacts. In Europe, emission controls that aimed at restoring ecological status were based on hindcasts from process-based models or paleolimnological reconstructions. For instance, 1860 is used in Europe as the target for restoration from acidification concerning biological and chemical parameters. A more practical problem is that the historical states of ecosystems and their function cannot be observed directly. Therefore, we (i) compare estimates of acidification based on long-term observations of roach (Rutilus rutilus) populations with hindcast pH from the hydrogeochemical model MAGIC; (ii) discuss policy implications and possible scope for use of long-term archival data for assessing human impacts on the natural environment and (iii) present a novel conceptual model for interpreting the importance of physico-chemical and ecological deviations from reference conditions. Of the 85 lakes studied, 78 were coherently classified by both methods. In 1980, 28 lakes were classified as acidified with the MAGIC model, however, roach was present in 14 of these. In 2010, MAGIC predicted chemical recovery in 50% of the lakes, however roach only recolonized in five lakes after 1990, showing a lag between chemical and biological recovery. Our study is the first study of its kind to use long-term archival biological data in concert with hydrogeochemical modeling for regional assessments of anthropogenic acidification. Based on our results, we show how the conceptual model can be used to understand and prioritize management of physico-chemical and ecological effects of anthropogenic stressors on surface water quality. PMID:24535943

  15. Assessing anthropogenic impact on boreal lakes with historical fish species distribution data and hydrogeochemical modeling.

    PubMed

    Valinia, Salar; Englund, Göran; Moldan, Filip; Futter, Martyn N; Köhler, Stephan J; Bishop, Kevin; Fölster, Jens

    2014-09-01

    Quantifying the effects of human activity on the natural environment is dependent on credible estimates of reference conditions to define the state of the environment before the onset of adverse human impacts. In Europe, emission controls that aimed at restoring ecological status were based on hindcasts from process-based models or paleolimnological reconstructions. For instance, 1860 is used in Europe as the target for restoration from acidification concerning biological and chemical parameters. A more practical problem is that the historical states of ecosystems and their function cannot be observed directly. Therefore, we (i) compare estimates of acidification based on long-term observations of roach (Rutilus rutilus) populations with hindcast pH from the hydrogeochemical model MAGIC; (ii) discuss policy implications and possible scope for use of long-term archival data for assessing human impacts on the natural environment and (iii) present a novel conceptual model for interpreting the importance of physico-chemical and ecological deviations from reference conditions. Of the 85 lakes studied, 78 were coherently classified by both methods. In 1980, 28 lakes were classified as acidified with the MAGIC model, however, roach was present in 14 of these. In 2010, MAGIC predicted chemical recovery in 50% of the lakes, however roach only recolonized in five lakes after 1990, showing a lag between chemical and biological recovery. Our study is the first study of its kind to use long-term archival biological data in concert with hydrogeochemical modeling for regional assessments of anthropogenic acidification. Based on our results, we show how the conceptual model can be used to understand and prioritize management of physico-chemical and ecological effects of anthropogenic stressors on surface water quality.

  16. Distribution of lead-203 in human peripheral blood in vitro.

    PubMed Central

    Ong, C N; Lee, W R

    1980-01-01

    In-vitro experiments using 203Pb were performed to identify the lead binding components in human peripheral blood. The distribution of lead in plasma, in the red cell membrane, and within the red cell was also investigated. Studies of the distribution of 203Pb in whole blood showed that at a lead concentration of 2.45 mumol/l (50 micrograms/100 ml) about 94% of lead had been incorporated by the erythrocytes and 6% remained in the plasma. After extraction of lipid by a methanol/chloroform mixture, about 75% of the lead was found to be associated with the protein fraction. The lipid contained about 21% of the 203Pb, the remainder being in the aqueous plasma. SDS polyacrylamide gel electrophoresis of blood plasma showed that almost 90% of the 203Pb was present in the albumin fraction; the remainder was likely to be associated with high molecular weight globulins. Several binding sites were identified on the erythrocyte membrane. The high molecular weight component, about 130 000-230 000, was the most important 203Pb binding site. Chemical modification of membrane proteins suggested that the carboxyl groups are the major ligand responsible for most of the lead binding. SH groups of the membrane may have a minor role, but amino groups did not appear to affect the lead binding. The binding of lead to erythrocytes was not confined to membranes, over 80% of lead in blood penetrates into erythrocytes and binds to intracellular components. Gel chromatography of the haemolysate showed that over 90% of the 203Pb was attached to the haemoglobin molecule. PMID:7370196

  17. Spatial distribution of soil lead pollution in Milwaukee County, Wisconsin

    SciTech Connect

    Brinkmann, R.

    1989-01-01

    The spatial distribution of lead pollution in soils of Milwaukee County, Wisconsin, was investigated to find the patterns and extent of health-threatening contamination. Samples were collected within three distinct land-use types: (i) lawns and gardens, (ii) major east-west arterials, and (iii) private properties at site-specific locations. Three-hundred and sixty-four soil samples were collected from lawns and gardens throughout the county; a total of 263 soil samples were collected along College Avenue, Oklahoma Avenue, Greenfield Avenue, Wisconsin Avenue, North Avenue, Capitol Drive, and Brown Deer Road, and a total of 55 soil samples were collected from three private properties. Several distinct patterns emerged from the mapped data. Broadly, soil lead pollution in lawns and gardens was highest in the central city and decreased north, south, and west toward the county lines and suburban fringe. Also, soil lead pollution along major arterials decreased away from busy intersections and was generally eliminated east of 42nd Street. At the three locations of intense sampling for site-specific examination, soil lead was concentrated within one meter of painted structures. Peripheral to the one meter zone, background levels of lead were found except in the central city where elevated soil lead levels were found in lawns. Health-threatening lead levels (>500 ppm) were found in soils collected using all three approaches: 24% of 11 soils collected from lawns and gardens; 43% of soils collected from major east-west arterials; and 27% of the soils collected from all three intensely examined properties. The sources of lead pollution in soil were more clearly suggested in intense sampling within small private properties. Lead-based paint caused contamination within one meter of painted structures and airborne lead from automobile exhaust outside that zone.

  18. Isotopic identification of natural vs. anthropogenic lead sources in marine sediments from the inner Ría de Vigo (NW Spain).

    PubMed

    Álvarez-Iglesias, P; Rubio, B; Millos, J

    2012-10-15

    San Simón Bay, the inner part of the Ría de Vigo (NW Spain), an area previously identified as highly polluted by Pb, was selected for the application of Pb stable isotope ratios as a fingerprinting tool in subtidal and intertidal sediment cores. Lead isotopic ratios were determined by inductively coupled plasma mass spectrometry on extracts from bulk samples after total acid digestion. Depth-wise profiles of (206)Pb/(207)Pb, (206)Pb/(204)Pb, (207)Pb/(204)Pb, (208)Pb/(204)Pb and (208)Pb/(207)Pb ratios showed, in general, an upward decrease for both intertidal and subtidal sediments as a consequence of the anthropogenic activities over the last century, or centuries. Waste channel samples from a nearby ceramic factory showed characteristic Pb stable isotope ratios different from those typical of coal and petrol. Natural isotope ratios from non-polluted samples were established for the study area, differentiating sediments from granitic or schist-gneiss sources. A binary mixing model employed on the polluted samples allowed estimating the anthropogenic inputs to the bay. These inputs represented between 25 and 98% of Pb inputs in intertidal samples, and 9-84% in subtidal samples, their contributions varying with time. Anthropogenic sources were apportioned according to a three-source model. Coal combustion-related emissions were the main anthropogenic source Pb to the bay (60-70%) before the establishment of the ceramic factory in the area (in the 1970s) which has since constituted the main source (95-100%), followed by petrol-related emissions. The Pb inputs history for the intertidal area was determined for the 20th century, and, for the subtidal area, the 19th and 20th centuries.

  19. Leading Twist Parton Distribution Amplitudes in Heavy Vector Mesons

    NASA Astrophysics Data System (ADS)

    Gao, Fei; Ding, Minghui; Chang, Lei; Liu, Yu-Xin; Roberts, Craig D.

    2016-03-01

    We employed QCD's Dyson-Schwinger equations (DSEs) for heavy quarks and obtained the leading twist parton distribution amplitudes (PDAs) in heavy vector mesons J/Ψ and ϒ. We found that all of the amplitudes are narrower than the asymptotic form, while they deviate from δ function. This indicates that the interaction between the two continent quarks are still important in the mesons consisted of charm and bottom quarks.

  20. Distribution of anthropogenic fill material within the Y-12 plant area, Oak Ridge, Tennessee

    SciTech Connect

    Sutton, G.E. Jr. |; Field, S.M.

    1995-10-01

    Widespread groundwater contamination in the vicinity of the Oak Ridge Y-12 Plant has been documented through a variety of monitoring efforts since the late 1970s. Various contaminants, most notably volatile organic compounds (VOCs), have migrated through the subsurface and formed extensive contaminant plumes within the Knox Aquifer/Maynardville Limestone, the primary exit pathway for groundwater transport within the Bear Creek Valley. In 1991, an integrated, comprehensive effort (Upper East Fork Poplar Creek [UEFPC] Phase I monitoring network) was initiated in order to (1) identify contaminant source areas within the industrialized portions of the plant and (2) define contamination migration pathways existing between the source areas and the Knox Aquifer/Maynardville Limestone. Data obtained during previous studies have indicated that extensive zones of fill and buried utility trenches may serve as preferred migration pathways. In addition, portions of UEFPC were rerouted, with several of its tributaries being filled during the initial construction of the plant. These filled surface drainage features are also believed to serve as preferred migration pathways. The identification of preferred contaminant migration pathways within the Y-12 Plant area is essential and required to refine the current Bear Creek Valley groundwater conceptual model and to assist in the selection of technically feasible and cost effective remedial strategies. This report presents the results of an initial investigation of the occurrence of manmade (anthropogenic) fill and its effect upon groundwater movement within the plant area. These interpretations are subject to revision and improvement as further investigation of the effects of the fill upon contaminant migration progresses.

  1. Anthropogenic impacts on the distribution and biodiversity of benthic macroinvertebrates and water quality of the Langat River, Peninsular Malaysia.

    PubMed

    Azrina, M Z; Yap, C K; Rahim Ismail, A; Ismail, A; Tan, S G

    2006-07-01

    A study of the impacts of anthropogenic activities on the distribution and biodiversity of benthic macroinvertebrates and water quality of the Langat River (Peninsular Malaysia) was conducted. Four pristine stations from the upstream and 4 stations at the downstream receiving anthropogenic impacts were selected along the river. For 4 consecutive months (March-June 1999), based on the Malaysian DOE (Malaysia Environmental Quality Report 2000, Department of Environment, Ministry of Science, Technology and Environment Malaysia. Maskha Sdn. Bhd. Kuala Lumpur, 86pp; Malaysia Environmental Quality Report 2001, Department of Environment, Ministry of Science, Technology and the Environment Malaysia) water quality index classes, the upstream stations recorded significantly (P<0.05) higher Biological Monitoring Working Party scores and better water quality indices than those of the downstream. The total number of macrobenthic taxa and their overall richness indices and diversity indices were significantly (P<0.05) higher at the upstream stations (54 taxa) than at the downstream stations (5 taxa). The upstream of the Langat River was dominated by Ephemeroptera and chironomid dipterans while other orders found in small quantities included Trichoptera, Diptera, Plecoptera, Odonata, Ephemeraptera, Coleoptera, and Gastropoda. On the other hand, the downstream of the river was mainly inhabited by the resistant Oligochaeta worms Limnodrilus spp. and Branchiodrilus sp. and Hirudinea in small numbers. The relationships between the physicochemical and the macrobenthic data were investigated by Pearson correlation analysis and multiple stepwise regression analysis. These statistical analyses showed that the richness and diversity indices were generally influenced by the total suspended solids and the conductivity of the river water. This study also highlighted the impacts of anthropogenic land-based activities such as urban runoff on the distribution and species diversity of

  2. Lead distribution in soils impacted by a secondary lead smelter: Experimental and modelling approaches.

    PubMed

    Schneider, Arnaud R; Cancès, Benjamin; Ponthieu, Marie; Sobanska, Sophie; Benedetti, Marc F; Pourret, Olivier; Conreux, Alexandra; Calandra, Ivan; Martinet, Blandine; Morvan, Xavier; Gommeaux, Maxime; Marin, Béatrice

    2016-10-15

    Smelting activities are one of the most common sources of trace elements in the environment. The aim of this study was to determine the lead distribution in upper horizons (0-5 and 5-10cm) of acidic soils in the vicinity of a lead-acid battery recycling plant in northern France. The combination of chemical methods (sequential extractions), physical methods (Raman microspectroscopy and scanning electron microscopy with an energy dispersive spectrometer) and multi-surface complexation modelling enabled an assessment of the behaviour of Pb. Regardless of the studied soil, none of the Pb-bearing phases commonly identified in similarly polluted environments (e.g., anglesite) were observed. Lead was mainly associated with organic matter and manganese oxides. The association of Pb with these soil constituents can be interpreted as evidence of Pb redistribution in the studied soils following smelter particle deposition.

  3. A century long sedimentary record of anthropogenic lead (Pb), Pb isotopes and other trace metals in Singapore.

    PubMed

    Chen, Mengli; Boyle, Edward A; Switzer, Adam D; Gouramanis, Chris

    2016-06-01

    Reconstructing the history of metal deposition in Singapore lake sediments contributes to understanding the anthropogenic and natural metal deposition in the data-sparse Southeast Asia. To this end, we present a sedimentary record of Pb, Pb isotopes and eleven other metals (Ag, As, Ba, Cd, Co, Cr, Cu, Ni, Tl, U and Zn) from a well-dated sediment core collected near the depocenter of MacRitchie Reservoir in central Singapore. Before the 1900s, the sedimentary Pb concentration was less than 2 mg/kg for both soil and sediment, with a corresponding (206)Pb/(207)Pb of ∼1.20. The Pb concentration increased to 55 mg/kg in the 1990s, and correspondingly the (206)Pb/(207)Pb decreased to less than 1.14. The (206)Pb/(207)Pb in the core top sediment is concordant with the (206)Pb/(207)Pb signal of aerosols in Singapore and other Southeast Asian cities, suggesting that Pb in the reservoir sediment was mainly from atmospheric deposition. Using the Pb concentration in the topmost layer of sediment, the estimated atmospheric Pb flux in Singapore today is ∼1.6 × 10(-2) g/m(2) yr. The concentrations of eleven other metals preserved in the sediment were also determined. A principal component analysis showed that most of the metals exhibit an increasing trend towards 1990s with a local concentration peak in the mid-20(th) century.

  4. A century long sedimentary record of anthropogenic lead (Pb), Pb isotopes and other trace metals in Singapore.

    PubMed

    Chen, Mengli; Boyle, Edward A; Switzer, Adam D; Gouramanis, Chris

    2016-06-01

    Reconstructing the history of metal deposition in Singapore lake sediments contributes to understanding the anthropogenic and natural metal deposition in the data-sparse Southeast Asia. To this end, we present a sedimentary record of Pb, Pb isotopes and eleven other metals (Ag, As, Ba, Cd, Co, Cr, Cu, Ni, Tl, U and Zn) from a well-dated sediment core collected near the depocenter of MacRitchie Reservoir in central Singapore. Before the 1900s, the sedimentary Pb concentration was less than 2 mg/kg for both soil and sediment, with a corresponding (206)Pb/(207)Pb of ∼1.20. The Pb concentration increased to 55 mg/kg in the 1990s, and correspondingly the (206)Pb/(207)Pb decreased to less than 1.14. The (206)Pb/(207)Pb in the core top sediment is concordant with the (206)Pb/(207)Pb signal of aerosols in Singapore and other Southeast Asian cities, suggesting that Pb in the reservoir sediment was mainly from atmospheric deposition. Using the Pb concentration in the topmost layer of sediment, the estimated atmospheric Pb flux in Singapore today is ∼1.6 × 10(-2) g/m(2) yr. The concentrations of eleven other metals preserved in the sediment were also determined. A principal component analysis showed that most of the metals exhibit an increasing trend towards 1990s with a local concentration peak in the mid-20(th) century. PMID:26967352

  5. Lead and aluminum in Atlantic surface waters (50°N to 50°S) reflecting anthropogenic and natural sources in the Eolian transport

    NASA Astrophysics Data System (ADS)

    Helmers, Eckard; Rutgers van der Loeff, Michiel M.

    1993-01-01

    Lead and aluminum were measured with a 40-100 km resolution in surface water on two transects across the Atlantic Ocean, one in May 1990 from Cape Town to the North Sea, the other in November 1990 from the North Sea to the Strait of Magellan. Samples were drawn 14 m below surface at normal speed from a 2-m-long snorkel system mounted on the bottom of the ship directly into a clean-room area. In the tropics, both Pb and Al show maximum concentrations in the Intertropical Convergence Zone (ITCZ) correlated with each other and with minimum salinities, indicating wet deposition as their common source. Even in this area characterized by large inputs of mineral aerosols, the Pb/Al ratio shows that the major source of soluble lead (>95%) is anthropogenic. At higher latitudes, Al is low throughout (10-20 nmol/kg), whereas enhanced Pb values show the anthropogenic inputs off south Africa, northern Argentina and especially western Europe. Very low Pb and especially Al concentrations in the upwelling areas associated with the Canary and Benguela currents show that the enhanced biogenic particle fluxes cause an efficient scavenging of both lithogenic particles known to arrive here by dry deposition, and of the adhering reactive trace metals.

  6. Mediated distribution pattern of organic compounds in estuarine sediment by anthropogenic debris.

    PubMed

    Wu, Chen-Chou; Bao, Lian-Jun; Tao, Shu; Zeng, Eddy Y

    2016-09-15

    Natural organic matter and grain size are considered as important parameters dictating the transport and fate of organic compounds in sediment. However, increasing evidence suggested that manufactured debris may alter the underlying mechanisms for biogeochemical cycling of organic compounds. To examine this assumption, estuarine sediment and embedded debris were collected from a fishery base in Guangdong Province of South China and analyzed for organophosphorus flame retardants (OPFRs), phthalates (PAEs), organotin compounds (OTs) and dichlorodiphenyltrichloroethanes (DDTs). Coarse-size debris (>200μm) were heterogeneously distributed in sediment, and most abundant near the boat maintenance facilities, aquaculture zone and shipping channel. The median concentrations of OPFRs, OTs, PAEs and DDTs in debris were 11, 0.2, 11 and 3.9μgg(-1) dry sample weight(-1), respectively, 1 to 3 orders of magnitude greater than those in bulk sediment (19, 60, 240 and 570ngg(-1) dry sample weight(-1), respectively). Furthermore, OPFRs, OTs and PAEs were mostly (>99%) enriched in coarse-size (63-2000μm) sediment, and there was no significant correlation (p>0.05) between the concentrations of OPFRs, OTs and PAEs in bulk and size-fractioned sediment samples and total organic carbon or grain size, similar to the distribution pattern of DDTs reported previously. When distinct debris were removed from the light-density (<1.7gcm(-3)) fraction of coarse-size (200-2000μm) sediment, the concentration levels of OPFRs, OTs, PAEs and DDTs declined by 84%, 59%, 55% and 7%, respectively. Obviously, debris irregularly distributed in sediment can alter the sediment sorption capacity for OPFRs, OTs and PAEs, and thus may undermine the significance of organic matter and grain size to the distribution of organic chemicals in sediment. Finally, commonly used procedures for preparing sediment samples and screening of debris may disturb the grain size distribution or underestimate the abundance of

  7. Mediated distribution pattern of organic compounds in estuarine sediment by anthropogenic debris.

    PubMed

    Wu, Chen-Chou; Bao, Lian-Jun; Tao, Shu; Zeng, Eddy Y

    2016-09-15

    Natural organic matter and grain size are considered as important parameters dictating the transport and fate of organic compounds in sediment. However, increasing evidence suggested that manufactured debris may alter the underlying mechanisms for biogeochemical cycling of organic compounds. To examine this assumption, estuarine sediment and embedded debris were collected from a fishery base in Guangdong Province of South China and analyzed for organophosphorus flame retardants (OPFRs), phthalates (PAEs), organotin compounds (OTs) and dichlorodiphenyltrichloroethanes (DDTs). Coarse-size debris (>200μm) were heterogeneously distributed in sediment, and most abundant near the boat maintenance facilities, aquaculture zone and shipping channel. The median concentrations of OPFRs, OTs, PAEs and DDTs in debris were 11, 0.2, 11 and 3.9μgg(-1) dry sample weight(-1), respectively, 1 to 3 orders of magnitude greater than those in bulk sediment (19, 60, 240 and 570ngg(-1) dry sample weight(-1), respectively). Furthermore, OPFRs, OTs and PAEs were mostly (>99%) enriched in coarse-size (63-2000μm) sediment, and there was no significant correlation (p>0.05) between the concentrations of OPFRs, OTs and PAEs in bulk and size-fractioned sediment samples and total organic carbon or grain size, similar to the distribution pattern of DDTs reported previously. When distinct debris were removed from the light-density (<1.7gcm(-3)) fraction of coarse-size (200-2000μm) sediment, the concentration levels of OPFRs, OTs, PAEs and DDTs declined by 84%, 59%, 55% and 7%, respectively. Obviously, debris irregularly distributed in sediment can alter the sediment sorption capacity for OPFRs, OTs and PAEs, and thus may undermine the significance of organic matter and grain size to the distribution of organic chemicals in sediment. Finally, commonly used procedures for preparing sediment samples and screening of debris may disturb the grain size distribution or underestimate the abundance of

  8. Distribution of chemical elements in attic dust and soil as reflection of lithology and anthropogenic influence in Slovenia

    NASA Astrophysics Data System (ADS)

    Sajn, R.

    2003-05-01

    The aim of this study was to establish contents and distribution of chemical elements in attic dust in Slovenia, and to define them according to geology and anthiopogenic influence. Attic dust and topsoil (0-5 cm) samples were collected in the rural area in settlements without known industry and in six largest towns in Slovenia. Analysis of 42 chemical elements was performed. For estimation of the association between elements and sampling materials the R mode factor analysis was applied. Al, Ba, Co, Ci, Fe, La, Mn, Na, Nb, Ni, Sc, Th, Ti, Y, V and Zr in attic dust reflect the natural distribution. The highest elemental contents in attic dust occur in the areas of igneous and metmoiphic rocks and of flysch formation. High contents of the elemental association Co, Ci, Fe, Mn, and Ni reflect also centuries of ferrous metallurgy. Distribution of As, Cd, Cu, Hg, Mo, Sb, Sn, Sr, Pb and Zn represents the anthropogenically introduced chemical elements. Their averages in attic dust are higher compared to topsoil. High contents of these elements are a result of historical Pb-Zn mining and smelting.

  9. Estimation of surface anthropogenic radioactivity concentrations from NaI(Tl) pulse-height distribution observed at monitoring station.

    PubMed

    Hirouchi, J; Yamazawa, H; Hirao, S; Moriizumi, J

    2015-04-01

    A method of estimating surface radioactivity concentrations of key anthropogenic radionuclides from NaI(Tl) pulse-height distribution observed at a monitoring station (MS) was discussed. In the estimation, a realistic assumption on geometric distribution of source and obstacles around the detector of the MS including the infiltration of radionuclides into the ground was used and the results were compared with ones with a commonly used assumption of a uniformly distributed plane source. The surface radioactivity concentration was determined by comparing the count rates at the full-energy peak ranges between observation and calculation with an electron-photon transport code EGS5. It was shown that the estimated absolute values of concentration differed by a factor of ∼1.5 depending on the assumption of infiltration depth. The estimated surface concentrations of (131)I, (134)Cs and (137)Cs were in good agreement with ones determined by the in situ measurements with an HPGe detector and the cumulative values of daily surface depositions. PMID:25313172

  10. Determination of the provenance of cocoa by soil protolith ages and assessment of anthropogenic lead contamination by pb/nd and lead isotope ratios.

    PubMed

    Manton, William I

    2010-01-27

    The Pb contents of chocolate and the products it flavors are among the highest of all commonly consumed substances. Others have shown that this Pb is acquired by cocoa beans after harvesting and is concentrated in their shells, portions of which are ground up with the cotyledons during processing. It is shown here that the shells also contain the lanthanides Nd and Sm, which they appear to take up more slowly than Pb when dried on bare soil. Consideration of Pb/Nd ratios, model Sm-Nd ages and the isotope ratios of Pb and Sr indicates that, in the absence of contamination, the relationship between Pb and Nd in shells is y = 13.1x(-0.383), where x is the Nd concentration in microg/kg and y is the Pb/Nd ratio. For cocoa powders, the relationship is y = 114x(-0.988). Samples that plot above these curves are probably contaminated. Model ages indicate where the cocoa of cocoa powders is grown, and these same considerations point to African samples being uncontaminated but samples from Asia containing 50% anthropogenic Pb of Australian origin. No measurable Pb contamination occurs during the transport of beans and the manufacture of chocolate.

  11. Factors affecting the distribution of natural and anthropogenic radionuclides in the coastal Burullus Lake.

    PubMed

    El-Reefy, H I; Badran, H M; Sharshar, T; Hilal, M A; Elnimr, T

    2014-08-01

    In the present study, measurements of naturally occurring radioactive materials and (137)Cs activity in sediment were conducted for locations covering the entire Burullus Lake in order to gather information about radionuclides mobility and distribution. Low-background γ-spectrometry was employed to determine the activity concentrations of water and sediment samples. The activity concentrations of (226)Ra and (232)Th are close to uniform distribution in the lake environment. Among the different physical and chemical characteristics measured for water and sediment, only salinity and total organic matter content have the potential to affect the mobility of (137)Cs and (40)K. The results suggest that these two radionuclides are attached to different mobile particulates. Increasing salinity tends to strengthen the adsorption of (137)Cs and solubilization of (40)K in sediment. On the other hand, sediment with high organic matter content traps (137)Cs and (40)K associated particulates to bottom sediment.

  12. Factors affecting the distribution of natural and anthropogenic radionuclides in the coastal Burullus Lake.

    PubMed

    El-Reefy, H I; Badran, H M; Sharshar, T; Hilal, M A; Elnimr, T

    2014-08-01

    In the present study, measurements of naturally occurring radioactive materials and (137)Cs activity in sediment were conducted for locations covering the entire Burullus Lake in order to gather information about radionuclides mobility and distribution. Low-background γ-spectrometry was employed to determine the activity concentrations of water and sediment samples. The activity concentrations of (226)Ra and (232)Th are close to uniform distribution in the lake environment. Among the different physical and chemical characteristics measured for water and sediment, only salinity and total organic matter content have the potential to affect the mobility of (137)Cs and (40)K. The results suggest that these two radionuclides are attached to different mobile particulates. Increasing salinity tends to strengthen the adsorption of (137)Cs and solubilization of (40)K in sediment. On the other hand, sediment with high organic matter content traps (137)Cs and (40)K associated particulates to bottom sediment. PMID:24657852

  13. A methodology for developing distribution of anthropogenic heating flux parts in mega-cities: A case study in the Tehran region

    NASA Astrophysics Data System (ADS)

    Malakooti, H.; Nagafi, M. A.; Krpo, A.; Sportisse, B.; Clappier, A.

    2009-04-01

    The diurnal profile and distribution of anthropogenic heating flux in Tehran mega-city is discussed on the basis of a defined heat emission inventory method that includes waste heat from vehicles traffic, electricity and fouls consumption in building, industrial sectors and metabolism. Spatial and temporal distribution of anthropogenic heating components is developed separately base on prepared GIS database for this purpose including key parameters such as landuse, population density, traffic parameters etc with all diurnal consumption profile that is generated for each subcategory. This methodology is adapted in order estimation of anthropogenic heat flux parts in order introducing into multi-scale meteorological modeling systems including mesoscale, urban canopy and building energy models (MM, UCM and BEM). Representative winter and summer weekday city-scale profiles are developed in order study of trends in this scale. The diurnal profiles have morning and evening peaks, with summertime and wintertime maxima up to 44 and 65 Wm2 respectively. The foul consumption component is the main one in winter with a 54% share and traffic with 44% in summer. Based on our distribution analysis with 500 meter resolution of Tehran region we find that the urban core region may have anthropogenic heating values 4-7 times the magnitudes of the city-scale values presented in this paper, especially in morning and evening and with higher spatial resolution, it is observed values more than this too. Keyworks: Heat islands; Urban energy balance; Anthropogenic heat; GIS; Tehran

  14. Source and distribution of sedimentary thallium in the Bohai Sea: Implications for hydrodynamic forces and anthropogenic impact

    NASA Astrophysics Data System (ADS)

    Hu, Ningjing; Liu, Jihua; Shi, Xuefa

    2015-04-01

    Source and distribution of sedimentary thallium in the Bohai Sea: Implications for hydrodynamic forces and anthropogenic impact Hu Ningjing, Liu Jihua, Shi Xuefa First Institute of Oceanography, State Oceanic Administration, Qingdao 266061, China Thallium (Tl), a non-essential and highly toxic trace metal, is listed as priority toxic pollutant by the United States Environmental Protection Agency (USEPA) (Keith and Telliard, 1979). However, its geochemical cycling in aquatic environment has received far less attention than that of many other trace metals. This has been attributed to relatively little commercial interest in Tl and, until recently, problems inherent in its detection at environmental concentrations (Meeravali and Jiang, 2008). In this study, we investigated the sources, distribution and fate of Tl in surface sediments of the Bohai Sea (BS), China, based on the datasets of total Tl and chemical speciation of Tl of 408 surface sediment samples in the total entire BS. The enrichment factors and chemical speciation of Tl indicated that Tl in BS was dominated by natural Tl, although anthropogenic Tl contamination was observed in the Liuguhe River mouth; the mud deposits are the sinks of Tl and the regional currents and tide systems play a key role on the accumulation of Tl in BS. The distribution of Tl consistent with that of MnO and Fe2O3 as well as the level of Fe-Mn fraction is relatively high, indicating MnO and Fe2O3 influence the geochemical behaviors of Tl in the BS. Although the positive correlation between Tl and TOC is observed for the samples in the BS, however, level of Tl in oxidizable faction could be neglected, suggesting TOC might not be a major factor affecting the concentration of Tl in BS. The low proportion of Tl in the non-residual fraction dominated by the Fe-Mn oxides suggested that the labile Tl was controlled by the Fe-Mn oxides and Tl has a low bioavailability and a minor potential threat to biota in BS. Acknowledgements: this work

  15. Dynamical next-to-next-to-leading order parton distributions

    SciTech Connect

    Jimenez-Delgado, P.; Reya, E.

    2009-04-01

    Utilizing recent deep inelastic scattering measurements ({sigma}{sub r},F{sub 2,3,L}) and data on hadronic dilepton production we determine at next-to-next-to-leading order (NNLO) (3-loop) of QCD the dynamical parton distributions of the nucleon generated radiatively from valencelike positive input distributions at an optimally chosen low resolution scale (Q{sub 0}{sup 2}<1 GeV{sup 2}). These are compared with 'standard' NNLO distributions generated from positive input distributions at some fixed and higher resolution scale (Q{sub 0}{sup 2}>1 GeV{sup 2}). Although the NNLO corrections imply in both approaches an improved value of {chi}{sup 2}, typically {chi}{sub NNLO}{sup 2}{approx_equal}0.9{chi}{sub NLO}{sup 2}, present deep inelastic scattering data are still not sufficiently accurate to distinguish between NLO results and the minute NNLO effects of a few percent, despite the fact that the dynamical NNLO uncertainties are somewhat smaller than the NLO ones and both are, as expected, smaller than those of their standard counterparts. The dynamical predictions for F{sub L}(x,Q{sup 2}) become perturbatively stable already at Q{sup 2}=2-3 GeV{sup 2} where precision measurements could even delineate NNLO effects in the very small-x region. This is in contrast to the common standard approach but NNLO/NLO differences are here less distinguishable due to the larger 1{sigma} uncertainty bands. Within the dynamical approach we obtain {alpha}{sub s}(M{sub Z}{sup 2})=0.1124{+-}0.0020, whereas the somewhat less constrained standard fit gives {alpha}{sub s}(M{sub Z}{sup 2})=0.1158{+-}0.0035.

  16. Anthropogenic and natural lead isotopes in Fe-hydroxides and Fe-sulphates in a watershed associated with arsenic-enriched groundwater, Maine, USA

    USGS Publications Warehouse

    Ayuso, Robert A.; Foley, Nora K.

    2008-01-01

    A survey of the natural and anthropogenic sources of lead contributing to secondary minerals in sulphidic schists associated with arsenic-enriched groundwater in Coastal Maine shows that the most likely source is natural Pb, particularly from coexisting sulphide minerals. The secondary minerals also reflect notable contributions from anthropogenic Pb. The Pb isotopes establish pathways by which Pb, and by inference As, could have been transported from As-bearing minerals (arsenian pyrite, arsenopyrite, lollingite, orpiment, arsenic oxide and others), via sulphide oxidation or carbonation reactions into multiple generations of secondary minerals (goethite, hematite, jarosite, natrojarosite and others). Lead isotopic compositions of the sulphides and secondary minerals determined by thermal ionization mass spectrometry (n=53) range widely. Lead and As contents of the sulphides and secondary minerals overlap, and are generally positively correlated. Pyrite, the dominant sulphide in sulphidic schists associated with As-enriched groundwater in Coastal Maine, has values of 206Pb/204Pb from 18.186 to 18.391, 207Pb/204Pb from 15.617 to 15.657, 208Pb/204Pb from 38.052 to 38.210, 206Pb/207Pb from c. 1.1625 to 1.1760 and 208Pb/207Pb from c. 2.4276 to 2.4394. Mixtures of Fe-hydroxide and oxide minerals (predominantly goethite and hematite) and secondary Fe-sulphate minerals (jarosite, natrojarosite, rozenite and melanterite) in the sulphidic schists have overlapping but generally higher values of 206Pb/204Pb from 18.495 to 19.747 (one sample at 21.495), 207Pb/204Pb from 15.595 to 15.722 (one sample at 15.839), 208Pb/204Pb from 38.186 to 39.162,206Pb/207Pb from c.1.1860 to 1.2575 (one sample at 1.3855) and 208Pb/207Pb from c. 2.4441 to 2.4865 than the sulphides. Sulphides from Zn-Pb metal mines are somewhat less radiogenic than sulphides from the schists. Other sulphides (mostly pyrite) associated with pegmatites and granitic rocks are heterogeneous and more

  17. Estimating the in situ sediment-porewater distribution of PAHs and chlorinated aromatic hydrocarbons in anthropogenic impacted sediments

    SciTech Connect

    Hans Peter H. Arp; Gijs D. Breedveld; Gerard Cornelissen

    2009-08-15

    It has become increasingly apparent that the in situ sediment-porewater distribution behavior of organic compounds within anthropogenic impacted sediments is quite diverse, and challenging to generalize. Traditional models based on octanol-water partitioning generally overestimate native porewater concentrations, and modern approaches accounting for multiple carbon fractions, including black carbon, appear sediment specific. To assess the diversity of this sorption behavior, we collected all peer-reviewed total organic carbon (TOC)-normalized in situ sediment-porewater distribution coefficients, K{sub TOC}, for impacted sediments. This entailed several hundreds of data for PAHs, PCBs, PCDD/Fs, and chlorinated benzenes, covering a large variety of sediments, locations, and experimental methods. Compound-specific KTOC could range up to over 3 orders of magnitude. Output from various predictive models for individual carbonaceous phases found in impacted sediments, based on peer-reviewed polyparameter linear free energy relationships (PP-LFERs), Raoult's Law, and the SPARC online-calculator, were tested to see if any of the models could consistently predict literature K{sub TOC} values within a factor of 30 (i.e. about 1.5 orders of magnitude, or half the range of K{sub TOC} values). The Raoult's Law model and coal tar PP-LFER achieved the sought-after accuracy for all tested compound classes, and are recommended for general, regional-scale modeling purposes. As impacted sediment-porewater distribution models are unlikely to get more accurate than this, this review underpins that the only way to accurately obtain accurate porewater concentrations is to measure them directly, and not infer them from sediment concentrations. 86 refs., 2 figs., 3 tabs.

  18. Anthropogenic landscapes and pesticides distribution in waters of the river Júcar, Spain

    NASA Astrophysics Data System (ADS)

    Pascual-Aguilar, Juan Antonio; Andreu, Vicente; Masià, Ana; Picó, Yolanda

    2014-05-01

    The quality of river flows may be affected by farming activities whenever dissolve substances persist as nonpoint source pollutants. Among contaminants, the group of pesticides is associated to farming activities. Their extended use depends on the dominant farming practice and the type of crop that, in turn, will be reflected on the specific pollutants and concentrations found. Their identifation in surface waters may also depend on the size and structure (to landscape scale) of the agriculture land. Thus, to understand surface waters transport and hydrological connectivity of contaminants in river flows research to large basin scale is needed. In this work it is assumed that at large geographical scale pesticides and herbicides are related to major landscape land use-cover types. The methodological framework developed consisted on the application of environmental forensic criteria combining laboratory analytical water samples and cartographic analysis using Geographical Information Systems (GIS). To the detection and quantification of pesticides, the sampling strategy consisted in the collection of 15 water samples distributed alongside the River Júcar and its two main tributaries (River Cabriel and Magro), located in the River Júcar drainage Basin, Spain. 50 pesticides were identified and quantified by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). Geographical analysis were performed after geo-location of sampling points analytical results and integration in the GIS environment using land use-cover digital layers, togeheter with soil, lithology and topography layers. Out of 50 pesticides 20 were identified and 18 presented concentrations higher than the Limits of Quantification. Values ranged from 0.04 ng/L (Terbuthylazine-2 Hydroxy) to 79.39 ng/L (Carbendazim), 150.75 ng/L (Thiabenzadole) and 222.45 ng/L (Imazalil). Contaminants identified more frequently were Chlorpyriphos, Ethion, Chlorfenvinphos and Imazalil, found in 15, 13, 12 and

  19. The spatial distribution pattern of heavy metal concentrations in urban soils — a study of anthropogenic effects in Berehove, Ukraine

    NASA Astrophysics Data System (ADS)

    Vince, Tímea; Szabó, György; Csoma, Zoltán; Sándor, Gábor; Szabó, Szilárd

    2014-09-01

    In the present study we examined the Ba, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn contamination levels of the soils of Berehove, a small city in West-Ukraine. As a first step we determined the spatial distribution of the heavy metal contents of the urban soils; then, by studying the land use structure of the city and by statistical analysis we identified the major sources of contamination; we established a matrix of correlations between the heavy metal contents of the soils and the different types of land use; and finally, we drew a conclusion regarding the possible origin(s) of these heavy metals. By means of multivariate statistical analysis we established that of the investigated metals, Ba, Cd, Cu, Pb and Zn accumulated in the city's soils primarily as a result of anthropogenic activity. In the most polluted urban areas (i.e. in the industrial zones and along the roads and highways with heavy traffic), in the case of several metals (Ba, Cd, Cu, Pb, Zn) we measured concentration levels even two or three times higher than the threshold limit values. Furthermore, Cr, Fe and Ni are primarily of lithogenic origin; therefore, the soil concentrations of these heavy metals depend mainly on the chemical composition of the soil-forming rocks.

  20. Characterization of anthropogenic impacts in a large urban center by examining the spatial distribution of halogenated flame retardants.

    PubMed

    Wei, Yan-Li; Bao, Lian-Jun; Wu, Chen-Chou; Zeng, Eddy Y

    2016-08-01

    Anthropogenic impacts have continuously intensified in mega urban centers with increasing urbanization and growing population. The spatial distribution pattern of such impacts can be assessed with soil halogenated flame retardants (HFRs) as HFRs are mostly derived from the production and use of various consumer products. In the present study, soil samples were collected from the Pearl River Delta (PRD), a large urbanized region in southern China, and its surrounding areas and analyzed for a group of HFRs, i.e., polybrominated diphenyl ethers (PBDEs), decabromodiphenyl ethane, bis(hexachlorocyclopentadieno)cyclooctane (DP) and hexabromobenzene. The sum concentrations of HFRs and PBDEs were in the ranges of 0.66-6500 and 0.37-5700 (mean: 290 and 250) ng g(-1) dry weight, respectively, around the middle level of the global range. BDE-209 was the predominant compound likely due to the huge amounts of usage and its persistence. The concentrations of HFRs were greater in the land-use types of residency, industry and landfill than in agriculture, forestry and drinking water source, and were also greater in the central PRD than in its surrounding areas. The concentrations of HFRs were moderately significantly (r(2) = 0.32-0.57; p < 0.05) correlated with urbanization levels, population densities and gross domestic productions in fifteen administrative districts. The spatial distribution of DP isomers appeared to be stereoselective as indicated by the similarity in the spatial patterns for the ratio of anti-DP versus the sum of DP isomers (fanti-DP) and DP concentrations. Finally, the concentrations of HFRs sharply decreased with increasing distance from an e-waste recycling site, indicating that e-waste derived HFRs largely remained in local soil. PMID:27203466

  1. Effects of natural and anthropogenic processes in the distribution of marine litter in the deep Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Ramirez-Llodra, Eva; De Mol, Ben; Company, Joan B.; Coll, Marta; Sardà, Francesc

    2013-11-01

    The distribution, type and quantity of marine litter accumulated on the bathyal and abyssal Mediterranean seafloor has been studied in the framework of the Spanish national projects PROMETEO and DOS MARES and the ESF-EuroDEEP project BIOFUN. Litter was collected with an otter trawl and Agassiz trawl while sampling for megafauna on the Blanes canyon and adjacent slope (Catalan margin, north-western Mediterranean) between 900 and 2700 m depth, and on the western, central and eastern Mediterranean basins at 1200, 2000 and 3000 m depth. All litter was sorted into 8 categories (hard plastic, soft plastic, glass, metal, clinker, fabric, longlines and fishing nets) and weighed. The distribution of litter was analysed in relation to depth, geographic area and natural (bathymetry, currents and rivers) and anthropogenic (population density and shipping routes) processes. The most abundant litter types were plastic, glass, metal and clinker. Lost or discarded fishing gear was also commonly found. On the Catalan margin, although the data indicated an accumulation of litter with increasing depth, mean weight was not significantly different between depths or between the open slope and the canyon. We propose that litter accumulated in the canyon, with high proportions of plastics, has predominantly a coastal origin, while litter collected on the open slope, dominated by heavy litter, is mostly ship-originated, especially at sites under major shipping routes. Along the trans-Mediterranean transect, although a higher amount of litter seemed to be found on the Western Mediterranean, differences of mean weight were not significant between the 3 geographic areas and the 3 depths. Here, the shallower sites, also closer to the coast, had a higher proportion of plastics than the deeper sites, which had a higher proportion of heavy litter and were often affected by shipping routes. The weight of litter was also compared to biomass of megafauna from the same samples. On the Blanes slope

  2. Geogenic and Anthropogenic Moss Responsiveness to Element Distribution Around a Pb-Zn Mine, Toranica, Republic of Macedonia.

    PubMed

    Angelovska, Svetlana; Stafilov, Trajče; Šajn, Robert; Balabanova, Biljana

    2016-04-01

    Moss species (Homalothecium lutescens, Hypnum cupressiforme, Brachythecium glareosum, and Campthotecium lutescens) were used as suitable sampling media for biomonitoring the origin of heavy-metal pollution in the lead-zinc (Pb-Zn) mine "Toranica" near the Kriva Palanka town, Eastern Macedonia. The contents of 20 elements-silver (Ag), aluminum (Al), arsenic (As), barium (Ba), calcium (Ca), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), potassium (K), lithium (Li), magnesium (Mg), manganese (Mn), sodium (Na), nickel (Ni), Pb, strontium (Sr), vanadium (V), and (Zn) were determined by atomic emission spectrometry with inductively coupled plasma. Data processing was applied with combinations of multivariate statistical methods: factor analysis, principal component analysis, and cluster analysis. Moss' responsiveness to the atmospheric distribution of the selected elements was investigated in correlation to the specific geology of the region (soil dusting). Lithogenic distribution was characterized with the distribution of three dominant geochemical associations: F1: Al-Li-V-Cr-Ni-Co, F2: Ba-Ca-Sr, and F3: Cd-Zn-Pb-Cu. Spatial distribution was constructed for visualization of the factor deposition. Furthermore, air distribution (passive biomonitoring) versus soil geochemistry of the analyzed elements was examined. Significant correlations were singled out for Pb, Zn, and Cd and for Mg(moss)/Na(soil). Characteristic lithological anomaly characterized the presence of the oldest geological volcanic rocks. Zone 1 (Pb-Zn mine surrounding) presents a unique area with hydrothermal action of Pb-Zn mineralization leading to polymetallic enrichments in soil. This phenomenon strongly affects the environment, which is a natural geochemical imprint in this unique area (described with the strong dominance of the geochemical association Cd-Zn-Pb-Cu). PMID:26888226

  3. Anthropogenic radionuclide fluxes and distribution in bottom sediments of the cooling basin of the Ignalina Nuclear Power Plant.

    PubMed

    Marčiulionienė, D; Mažeika, J; Lukšienė, B; Jefanova, O; Mikalauskienė, R; Paškauskas, R

    2015-07-01

    Based on γ-ray emitting artificial radionuclide spectrometric measurements, an assessment of areal and vertical distribution of (137)Cs, (60)Co and (54)Mn activity concentrations in bottom sediments of Lake Drūkšiai was performed. Samples of bottom sediments from seven monitoring stations within the cooling basin were collected in 1988-1996 and 2007-2010 (in July-August). For radionuclide areal distribution analysis, samples from the surface 0-5 cm layer were used. Multi sample cores sliced 2 cm, 3 cm or 5 cm thick were used to study the vertical distribution of radionuclides. The lowest (137)Cs activity concentrations were obtained for two stations that were situated close to channels with radionuclide discharges, but with sediments that had a significantly smaller fraction of organic matter related to finest particles and consequently smaller radionuclide retention potential. The (137)Cs activity concentration was distributed quite evenly in the bottom sediments from other investigated monitoring stations. The highest (137)Cs activity concentrations in the bottom sediments of Lake Drūkšiai were measured in the period of 1988-1989; in 1990, the (137)Cs activity concentrations slightly decreased and they varied insignificantly over the investigation period. The obtained (238)Pu/(239,240)Pu activity ratio values in the bottom sediments of Lake Drūkšiai represented radioactive pollution with plutonium from nuclear weapon tests. Higher (60)Co and (54)Mn activity concentrations were observed in the monitoring stations that were close to the impact zones of the technical water outlet channel and industrial rain drainage system channel. (60)Co and (54)Mn activity concentrations in the bottom sediments of Lake Drūkšiai significantly decreased when operations at both INPP reactor units were stopped. The vertical distribution of radionuclides in bottom sediments revealed complicated sedimentation features, which may have been affected by a number of natural and

  4. Anthropogenic radionuclide fluxes and distribution in bottom sediments of the cooling basin of the Ignalina Nuclear Power Plant.

    PubMed

    Marčiulionienė, D; Mažeika, J; Lukšienė, B; Jefanova, O; Mikalauskienė, R; Paškauskas, R

    2015-07-01

    Based on γ-ray emitting artificial radionuclide spectrometric measurements, an assessment of areal and vertical distribution of (137)Cs, (60)Co and (54)Mn activity concentrations in bottom sediments of Lake Drūkšiai was performed. Samples of bottom sediments from seven monitoring stations within the cooling basin were collected in 1988-1996 and 2007-2010 (in July-August). For radionuclide areal distribution analysis, samples from the surface 0-5 cm layer were used. Multi sample cores sliced 2 cm, 3 cm or 5 cm thick were used to study the vertical distribution of radionuclides. The lowest (137)Cs activity concentrations were obtained for two stations that were situated close to channels with radionuclide discharges, but with sediments that had a significantly smaller fraction of organic matter related to finest particles and consequently smaller radionuclide retention potential. The (137)Cs activity concentration was distributed quite evenly in the bottom sediments from other investigated monitoring stations. The highest (137)Cs activity concentrations in the bottom sediments of Lake Drūkšiai were measured in the period of 1988-1989; in 1990, the (137)Cs activity concentrations slightly decreased and they varied insignificantly over the investigation period. The obtained (238)Pu/(239,240)Pu activity ratio values in the bottom sediments of Lake Drūkšiai represented radioactive pollution with plutonium from nuclear weapon tests. Higher (60)Co and (54)Mn activity concentrations were observed in the monitoring stations that were close to the impact zones of the technical water outlet channel and industrial rain drainage system channel. (60)Co and (54)Mn activity concentrations in the bottom sediments of Lake Drūkšiai significantly decreased when operations at both INPP reactor units were stopped. The vertical distribution of radionuclides in bottom sediments revealed complicated sedimentation features, which may have been affected by a number of natural and

  5. Lead transfer in maternal milk, and the absorption, retention, distribution and excretion of lead in suckling mice

    SciTech Connect

    Keller, Charles Arthur

    1980-01-01

    Suckling mice were found to absorb and retain a greater fraction of an oral lead dose than did adult mice. Pinocytotic activity and lead uptake (in vivo) were found to be greatest in the distal small intestinal tissue. Cortisone pretreatment results in precocious cessation of pinocytotic activity in the intestine of suckling mice. Cortisone pretreatment of adult mice had no effect on whole body lead retention or intestinal tissue content of lead following an oral dose. The data indicate that the distal small intestine is the site of active pinocytosis of lead, and that pinocytosis is the major mechanism involved in lead absorption in suckling mice. Developmental differences were also observed in the percentage of lead retained in the whole body. Both groups exhibited dose-independent lead retention, indicating a first-order absorption process for each age group. Lead distribution and elimination from organs also differed between suckling and adult mice. Developmental differences were observed in organ lead concentration for kidneys and brain following oral doses. Relative distribution of lead to the brains of suckling mice were greater than to adult brains. Whole body and bone lead elimination rates were reduced in suckling compared to adult mice. Brain lead elimination rates did not differ in suckling and adult mice. A lactating mouse model was developed to study lead transfer to suckling offspring. Lead was transferred in milk to suckling offspring from mothers which had previously ingested lead in the drinking water. Relative lead transfer to suckled offspring during lactation greatly exceeded transfer to fetuses during gestation. Lactation resulted in an increased rate of maternal lead elimination. Lead concentration in milk exceeded plasma concentration by a factor of approximately 25. (ERB)

  6. Measurement of resuspended aerosol in the Chernobyl area. Part III. Size distribution and dry deposition velocity of radioactive particles during anthropogenic enhanced resuspension.

    PubMed

    Garger, E K; Paretzke, H G; Tschiersch, J

    1998-10-01

    During anthropogenic activities, such as agricultural soil management and traffic on unpaved roads, size distribution measurements were performed of atmospheric particulate radionuclides at a site in the Chernobyl 30-km exclusion zone. Analysis of cascade impactor measurements showed an increase of the total atmospheric radioactivity. In the cases of harrowing by a tractor and traffic on unpaved roads, a common shape of the size distribution was found with two maxima, the first in the 2-4 microm range, the second in the 12-20 microm range. The size distributions were compared to measurements during wind-driven resuspension. Particle number concentration measurements with an Aerodynamic Particle Sizer showed a dynamic dependence of the particle concentration in different size ranges on anthropogenic action. The increase of the mean concentration was for the large particles more than one order of magnitude higher than for fine particles during anthropogenic enhanced resuspension. From the measurement of the mass concentration, the radioactive loading could be estimated. An enrichment of radionuclides on resuspended particles (compared to soil particles) was found, with the highest enrichment for large particles. Micrometeorological considerations showed that large particles may frequently be subject to medium range transport. The dry deposition velocity was measured; the mean value of 0.026 m s(-1) +/- 0.016 m s(-1) is typical for 6-9 microm diameter particles.

  7. The distribution of anthropogenic REE in the Dutch distributaries of the Rhine: the role of suspended matter

    NASA Astrophysics Data System (ADS)

    Roskam, Gerlinde; Verheul, Marc; Klaver, Gerard; Bakker, Ingrid

    2014-05-01

    In nature rare earth elements (REE) occur in fixed ratios; contamination with a single rare earth element causes a clear deviation from the natural NASC normalized REE-patterns: an anomaly. REE are progressively used in many high technology products and processes. For example, gadolinium-containing chelates have been used since the '80s as contrasting agent in MRI-imaging. The pertaining anomaly is currently used as a tracer for distinguishing waste water from water unaffected by anthropogenic contamination. In the Dutch monitoring program in the Rhine-Meuse distributaries, total (10% HNO3 digested) and dissolved (< 0.45 µm) fractions in surface water are routinely analysed, and with two-week intervals suspended matter samples are collected with a centrifuge. Since 2008, the set of analysed elements was extended with REE, enabling this study. Lobith, the entry point of the River Rhine in The Netherlands, shows an annual oscillation in the magnitude of the lanthanum (La) anomaly. This positive La-anomaly was reported by Kulaksiz and Bau in 2011; they identified the point source as a production plant for catalysts used in petroleum refining in the German city of Worms. Since the spring of 2011, samarium (Sm) is used in the same process, resulting in matching La- and Sm-anomalies. The anthropogenic La and Sm concentrations are predominantly present in the total fraction, which suggests that the anthropogenic La and Sm concentrations are associated with suspended matter. The anthropogenic La and Sm concentrations are lower in the suspended matter samples collected with the centrifuge, suggesting a bias of these La and Sm concentrations in the finer fraction of the suspended matter. The anthropogenic La en Sm concentrations remain relatively constant throughout the rivers, but close to Lake IJsselmeer and the North Sea, sedimentation causes a sharp decrease in the anthropogenic concentrations. Detailed sampling of sediments, suspended matter and water could give a

  8. Tissue lead distribution and hematologic effects in American kestrels (Falco sparverius) fed biologically incorporated lead

    USGS Publications Warehouse

    Custer, T.W.; Franson, J.C.; Pattee, O.H.

    1984-01-01

    American kestrels were fed a diet containing 0.5, 120, 212, and 448 ppm (dry wt) biologically incorporated lead (Pb) for 60 days. The diet consisted of homogenized 4-wk-old cockerels raised on feed mixed with and without lead. No kestrels died and weights did not differ among treatment groups. The control group (0.5 ppm Pb) had the lowest mean concentration of lead and the high dietary group had the highest for the following tissues: Kidney, liver, femur, brain, and blood. Concentrations of lead were significantly correlated among tissues. There were no differences among treatment groups for packed cell volume, hemoglobin concentration, or erythrocyte count.

  9. PREDICTING LEAD DISSOLUTION IN DRINKING WATER DISTRIBUTION SYSTEMS: EFFECT OF FLUORIDE ADDITIVES ON LEAD SOLUBILITY AND CORROSION

    EPA Science Inventory

    Many water systems have encountered difficulties in meeting the action levels established by the Lead and Copper Rule. Several chemical parameters contribute to the corrosion of lead plumbing and may influence the nature of the passivating films formed on distribution materials....

  10. Comparison between Synthesized Lead Particles and Lead Solids Formed on Surfaces in Real Drinking Water Distribution Systems

    EPA Science Inventory

    The objective of this work is to compare the properties of lead solids formed during bench-scale precipitation experiments to solids found on lead pipe removed from real drinking water distribution systems and metal coupons used in pilot scale corrosion testing. Specifically, so...

  11. Use of an inverse method to resolve the temporal and spatial distribution of anthropogenic and biogenic emissions in Atlanta, Georgia

    SciTech Connect

    Chang, M.E.; Hartley, D.; Cardelino, C.; Chang, W.L.

    1996-12-31

    The Urban Airshed Model (UAM) has been used by the State of Georgia in an attempt to demonstrate attainment of the ozone standard for Atlanta. A recent comparison of UAM data to ambient data collected during the 1992 Southern Oxidants Study Atlanta intensive revealed that the model accurately predicts ozone concentrations, but is poorly simulates the concurrent ozone precursors. There were discrepancies in both the anthropogenic and biogenic precursors. For anthropogenic emissions, the ambient ratios of anthropogenic hydrocarbons (AHC) to oxides of nitrogen (NO{sub x}), AHC/NO{sub x}, and carbon monoxide (CO) to NO{sub x}, CO/NO{sub x}, were higher than the emission ratios by 20% and 73% respectively. In this study, the authors use an inverse method to reconcile the differences between the observed and predicted concentrations of ozone precursors. Inverse methods have been successfully applied to many fields including medical imaging, missile guidance, and underground tomography. This study is the first to apply the inverse method to estimate the emissions of the relatively short-lived species important to urban oxidants formation.

  12. Nondiagonal parton distributions in the leading logarithmic approximation

    NASA Astrophysics Data System (ADS)

    Frankfurt, L. L.; Freund, A.; Guzey, V.; Strikman, M.

    1998-02-01

    In this paper we make predictions for nondiagonal parton distributions in a proton in the LLA. We calculate the DGLAP-type evolution kernels in the LLA, solve the nondiagonal GLAP evolution equations with a modified version of the CTEQ-package and comment on the range of applicability of the LLA in the asymmetric regime. We show that the nondiagonal gluon distribution g(x1,x2,t,μ2) can be well approximated at small x by the conventional gluon density xG(x,μ2).

  13. Changing epidemiology of trauma deaths leads to a bimodal distribution

    PubMed Central

    Gunst, Mark; Ghaemmaghami, Vafa; Gruszecki, Amy; Urban, Jill; Frankel, Heidi

    2010-01-01

    Injury mortality was classically described with a trimodal distribution, with immediate deaths at the scene, early deaths due to hemorrhage, and late deaths from organ failure. We hypothesized that the development of trauma systems has improved prehospital care, early resuscitation, and critical care and altered this pattern. This population-based study of all trauma deaths in an urban county with a mature trauma system reviewed data for 678 patients (median age, 33 years; 81% male; 43% gunshot, 20% motor vehicle crashes). Deaths were classified as immediate (scene), early (in hospital, ≤4 hours from injury), or late (>4 hours after injury). Multinomial regression was used to identify independent predictors of immediate and early versus late deaths, adjusted for age, gender, race, intention, mechanism, toxicology, and cause of death. Results showed 416 (61%) immediate, 199 (29%) early, and 63 (10%) late deaths. Compared with the classical description, the percentage of immediate deaths remained unchanged, and early deaths occurred much earlier (median 52 vs 120 minutes). However, unlike the classic trimodal distribution, the late peak was greatly diminished. Intentional injuries, alcohol intoxication, asphyxia, and injuries to the head and chest were independent predictors of immediate death. Alcohol intoxication and injuries to the chest were predictors of early death, while pelvic fractures and blunt assaults were associated with late deaths. In conclusion, trauma deaths now have a predominantly bimodal distribution. Near elimination of the late peak likely represents advancements in resuscitation and critical care that have reduced organ failure. Further reductions in mortality will likely come from prevention of intentional injuries and injuries associated with alcohol intoxication. PMID:20944754

  14. Impacts of Anthropogenic Emissions in the Southeastern U.S. on Heterogeneous Chemistry of Isoprene-Derived Epoxides Leading to Secondary Organic Aerosol Formation (Invited)

    NASA Astrophysics Data System (ADS)

    Surratt, J. D.; Pye, H.; Lin, Y.; Budisulistiorini, S.; Zhang, H.; Marth, W.; Cui, T.; Arashiro, M.; Chu, K.; Zhang, Z.; Sexton, K.; Piletic, I.; Xie, Y.; Capps, S. L.; Luecken, D.; Hutzell, W. T.; Jaoui, M.; Canagaratna, M. R.; Croteau, D.; Jayne, J. T.; Worsnop, D. R.; Offenberg, J.; Kleindienst, T. E.; Lewandowski, M.; Edney, E.; Pinder, R. W.; Bartolotti, L.; Gold, A.

    2013-12-01

    Isoprene is a major source of secondary organic aerosol (SOA); however, the exact manner in which it forms SOA remains unclear. Improving our fundamental understanding of isoprene-derived SOA is key to improving existing air quality models, especially in the southeastern U.S. where models currently underestimate observations. By combining organic synthesis, computational calculations, mass spectrometry, smog chamber studies, and field measurements, we show that reactive epoxides, which include methacrylic acid epoxide (MAE) and isomeric isoprene epoxydiols (IEPOX), produced from the photochemical oxidation of isoprene are key to SOA formation. Furthermore, anthropogenic pollutants (NOx and SO2) enhance isoprene-derived epoxides as an SOA source. In the laboratory, we find that the reactive uptake of synthetic IEPOX and MAE standards onto acidified sulfate aerosol yields known isoprene-derived SOA tracers (2-methlytetrols, 2-methylglyceric acid, C5-alkene triols, 3-methyltetrahydrofuran-3,4-diols, dimers and organosulfates) that we measure in fine aerosol collected from multiple sites across the southeastern U.S. using gas chromatography/mass spectrometry (GC/MS) and liquid chromatography coupled to diode array detection and electrospray ionization high-resolution quadrupole time-of-flight mass spectrometry (LC/DAD-ESI-QTOFMS). Notably, IEPOX- and MAE-derived SOA tracers account for ~19% of the organic aerosol mass in Yorkville, GA. Moreover, real-time continuous chemical measurements of fine aerosol made using an Aerodyne Aerosol Chemical Speciation Monitor (ACSM) during summer 2011 and summer 2013 in Atlanta, GA, and Look Rock, TN, respectively, resolved an IEPOX-oxygenated organic aerosol (IEPOX-OOA) factor when applying positive matrix factorization (PMF) to the organic mass spectral time series. In Atlanta, this factor is found to account for ~33% of the fine OA mass and is correlated with IEPOX-derived SOA tracers (r2 = 0.6), sulfate (r2 = 0.5), and to some

  15. Modeling the crystal distribution of lead-sulfate in lead-acid batteries with 3D spatial resolution

    NASA Astrophysics Data System (ADS)

    Huck, Moritz; Badeda, Julia; Sauer, Dirk Uwe

    2015-04-01

    For the reliability of lead-acid batteries it is important to have an accurate prediction of its response to load profiles. A model for the lead-sulfate growth is presented, which is embedded in a physical-chemical model with 3D spatial resolution is presented which is used for analyzing the different mechanism influencing the cell response. One import factor is the chemical dissolution and precipitation of lead-sulfate, since its dissolution speed limits the charging reaction and the accumulation of indissolvable of lead-sulfate leads to capacity degradation. The cell performance/behavior is not only determined by the amount of the sulfate but also by the radii and distribution of the crystals. The presented model can be used to for an improved understanding of the interaction of the different mechanisms.

  16. Trend analysis of carbon monoxide distributions for changes in fire vs. anthropogenic sources in diverse African regions

    NASA Astrophysics Data System (ADS)

    Worden, H. M.; Worden, J. R.; Bloom, A. A.; Bowman, K. W.

    2015-12-01

    Satellite measurements of atmospheric carbon monoxide (CO) provide a signature for biomass burning and anthropogenic combustion-related pollution emissions. CO plays an important role in both air quality and climate as a precursor for tropospheric ozone and as a major sink of OH, the atmospheric "detergent" that affects the lifetime of methane and other pollutants. Worden et al., [2013] showed decreasing global CO values in time series of satellite total column CO measurements over the past decade. All of the satellite instruments that measure CO in the thermal infrared showed consistent inter-annual variability due to fires and possibly the global recession in late 2008. Observed decreases in CO over N. America and Europe were consistent with expected decreases in CO emissions inventories [Granier et al., 2011], however, the decrease is not uniform globally. In particular, Africa shows regions with smaller negative trends and potentially increasing trends in CO concentration. Here we examine trends for surface and total column CO concentrations in Africa over 2002-2014 using MOPITT V5J data. Our hypothesis is that temporal changes in CO will have different signatures related to anthropogenic and biomass burning emissions. We use singular value decomposition (SVD) with time series from different regions based on vegetation type and population density to diagnose the dominant trends and their potential drivers.

  17. The distribution of blood lead levels and job titles among lead-acid battery workers in Taiwan.

    PubMed

    Chao, Kun-Yu; Shin, Wen-Yi; Chuang, Hung-Yi; Wang, Jung-Der

    2002-07-01

    There were several reports about elevated blood lead levels in lead battery workers. However, their subjects came from only one or several plants. We visited all the 23 registered lead-acid battery plants in Taiwan and collected their health examination records in 1992, the blood lead analyses of which were completed in 3 medical college hospitals. In total, we have obtained 1726 records. The average blood lead concentration was 37.1 ug/dl, and 37% of blood lead levels were more than 40 ug/dl (action level). The overall participation rate for health examination among employees was 69.4%. The participation rates were different among both plant sizes and job titles. Assuming that there was no peculiar variation within the four working zones (plate manufacture jobs, assembly jobs, part-time exposure jobs, and office jobs) in each plant, and that blood lead levels of our samples were stable after deleting newly hired workers, we estimated that the blood lead distributions of 2486 employees in these plants were 63.3%, 26.4%, 9.25% and 1.05% for below 40, 40-59, 60-79, and above 80 ug/dl respectively. We conclude that such an analysis should be performed each year to monitor the effectiveness of occupational hygiene in workplace of lead battery plants.

  18. Lead

    MedlinePlus

    ... Lead Share Facebook Twitter Google+ Pinterest Contact Us Lead Poisoning is Preventable If your home was built before ... of the RRP rule. Read more . Learn about Lead Poisoning Prevention Week . Report Uncertified Contractors and Environmental Violations ...

  19. Effects of dietary calcium on lead absorption, distribution, and elimination kinetics in rats

    SciTech Connect

    Aungst, B.J.; Fung, H.L.

    1985-01-01

    A pharmacokinetic analysis of lead absorption, distribution, and elimination was conducted in rats maintained on calcium-deficient, control, and calcium-supplemented diets. Dietary calcium affected lead disposition in a number of ways. Systematic lead clearance after a 10-mg/kg intracardiac lead dose was approximately 25% lower than control in rats administered dietary calcium supplements. In rats maintained on a calcium-deficient diet, systemic lead clearance was estimated to be 40% less than control. The apparent volume of lead distribution was increased. The apparent systemic availability of 1-, 10-, and 100-mg.kg oral lead doses was three- to fourfold greater than control in calcium-deficient rats. The percentage absorption was dose-dependent in control and calcium-deficient rats. The observed changes in lead absorption and systemic clearance associated with the calcium-deficient diet represent synergistic effects that could elevate blood lead accumulation and thus potentially influence susceptibility to lead toxicity.

  20. Distribution and integrated assessment of lead in an abandoned lead-acid battery site in Southwest China before redevelopment.

    PubMed

    Wang, Mei; Zhang, Chao; Zhang, Zhuo; Li, Fasheng; Guo, Guanlin

    2016-06-01

    Lead-acid battery sites have contributed enormous amounts of lead to the environment, significantly affecting its global biogeochemical cycle and leaving the potential risks to human health. An abandoned lead-acid battery site prepared for redevelopment was selected in order to study the distribution of lead in soils, plants, rhizosphere soils and soil solutions. In total, 197 samples from 77 boreholes were collected and analyzed. Single extractions by acetic acid (HOAc) were conducted to assess the bioavailability and speciation of lead in soils for comparison with the parts of the plants that are aboveground. Health risks for future residential development were evaluated by the integrated exposure uptake biokinetic (IEUBK) model. The results indicated that lead concentrations in 83% of the soil samples exceeded the Chinese Environmental Quality Standard for soil (350 mg/kg for Pb) and mainly occurred at depths between 0 and 1.5 m while accumulating at the surface of demolished construction waste and miscellaneous fill. Lead concentrations in soil solutions and HOAc extraction leachates were linked closely to the contents of aboveground Broussonetia papyrifera and Artemisia annua, two main types of local plants that were found at the site. The probability density of lead in blood (PbB) in excess of 10 µg/dL could overtake the 99% mark in the residential scenario. The findings provided a relatively integrated method to illustrate the onsite investigations and assessment for similar sites before remediation and future development from more comprehensive aspects.

  1. Distribution and integrated assessment of lead in an abandoned lead-acid battery site in Southwest China before redevelopment.

    PubMed

    Wang, Mei; Zhang, Chao; Zhang, Zhuo; Li, Fasheng; Guo, Guanlin

    2016-06-01

    Lead-acid battery sites have contributed enormous amounts of lead to the environment, significantly affecting its global biogeochemical cycle and leaving the potential risks to human health. An abandoned lead-acid battery site prepared for redevelopment was selected in order to study the distribution of lead in soils, plants, rhizosphere soils and soil solutions. In total, 197 samples from 77 boreholes were collected and analyzed. Single extractions by acetic acid (HOAc) were conducted to assess the bioavailability and speciation of lead in soils for comparison with the parts of the plants that are aboveground. Health risks for future residential development were evaluated by the integrated exposure uptake biokinetic (IEUBK) model. The results indicated that lead concentrations in 83% of the soil samples exceeded the Chinese Environmental Quality Standard for soil (350 mg/kg for Pb) and mainly occurred at depths between 0 and 1.5 m while accumulating at the surface of demolished construction waste and miscellaneous fill. Lead concentrations in soil solutions and HOAc extraction leachates were linked closely to the contents of aboveground Broussonetia papyrifera and Artemisia annua, two main types of local plants that were found at the site. The probability density of lead in blood (PbB) in excess of 10 µg/dL could overtake the 99% mark in the residential scenario. The findings provided a relatively integrated method to illustrate the onsite investigations and assessment for similar sites before remediation and future development from more comprehensive aspects. PMID:26921546

  2. Lead

    MedlinePlus

    ... obvious symptoms, it frequently goes unrecognized. CDC’s Childhood Lead Poisoning Prevention Program is committed to the Healthy People ... Lead Levels Information for Parents Tips for preventing lead poisoning About Us Overview of CDC’s Childhood Lead Poisoning ...

  3. Elemental composition, distribution and control of biogenic silica in the anthropogenically disturbed and pristine zone inter-tidal sediments of Indian Sundarbans mangrove-estuarine complex.

    PubMed

    Dhame, Shreya; Kumar, Alok; Ramanathan, Al; Chaudhari, Punarbasu

    2016-10-15

    Spatial distribution and interrelationship among organic nutrients - silica and carbon - and various lithogenic elements were investigated in the surficial sediments of Matla estuary and Core Zone of Indian Sundarbans Reserve Forest using spatial analysis and multivariate statistics. Biogenic silica (BSi), an important parameter for coastal biogeochemisry, was measured using Si-time alkaline leaching method. BSi concentration ranged from 0.01% to 0.85% with higher concentrations in upstream region of Matla estuary and attenuated values towards the bay, seemingly due to changes in hydrodynamics and land use conditions. Spatial distribution of BSi did not exhibit significant correlation with sediment parameters of organic carbon (OC), elemental composition and clay content. However, it showed significant contrasting trends with total phosphorus (TP) and total silica of human influenced Matla estuary sediments as well as the dissolved silica (DSi) of its surface waters. Anthropogenic influence on sediment geochemistry is discernable with the presence of higher concentrations of organic and inorganic elements in Matla estuary than in Core Zone sediments. Spatial variation trends are often challenging to interpret due to multiple sources of input, varying energy and salinity conditions and constant physical, chemical and biological alterations occurring in the environment. Nonetheless, it is certain that anthropogenic activities have a substantial influence on biogeochemical processes of Sundarbans mangrove-estuarine complex and potentially the coastal ocean. PMID:27480337

  4. Vertical Distribution of Lead and Mercury in the Wetland Argialbolls of the Sanjiang Plain in Northeastern China

    PubMed Central

    Lin, Chunye; Li, Peizhong; Cheng, Hongguang; Ouyang, Wei

    2015-01-01

    The wetland Argialbolls pedon was chosen to investigate the effects of pedogenic processes and anthropogenic activities on the vertical distribution of lead and mercury concentration and to assess the potential use of soil as an archive of atmospheric Pb and Hg pollution. The soil was sampled from 5 cm from the surface to a depth of 90 cm at two locations in the Sanjiang Plain in northeastern China. The soil was analyzed for pH, soil organic matter (SOM), Fe, Mn, and Al. The results indicate that the SOM concentration gradually decreased with depth, while Fe and Mn were reductively leached from the upper horizons and accumulated significantly in the lower argillic horizons. Atmospheric Pb and Hg deposition and their redistribution during the pedogenic process led to a unique vertical distribution in the wetland Argialbolls. Overall, Pb was leached from the upper horizons and then accumulated in the lower argillic horizons. However, the Hg concentration decreased with depth, following the SOM distribution. The Pb concentration was significantly correlated to the Fe and Mn concentrations in the Argialbolls profiles, while the Hg concentration was significantly correlated with SOM. Post-depositional mobility along the wetland Argialbolls profile is higher for Pb and low for Hg. Therefore, the Argialbolls profile does not provide an accurate reconstruction of atmospheric Pb deposition, but might provide an accurate reconstruction of net atmospheric Hg deposition. PMID:25894341

  5. Vertical Distribution of Lead and Mercury in the Wetland Argialbolls of the Sanjiang Plain in Northeastern China.

    PubMed

    Lin, Chunye; Li, Peizhong; Cheng, Hongguang; Ouyang, Wei

    2015-01-01

    The wetland Argialbolls pedon was chosen to investigate the effects of pedogenic processes and anthropogenic activities on the vertical distribution of lead and mercury concentration and to assess the potential use of soil as an archive of atmospheric Pb and Hg pollution. The soil was sampled from 5 cm from the surface to a depth of 90 cm at two locations in the Sanjiang Plain in northeastern China. The soil was analyzed for pH, soil organic matter (SOM), Fe, Mn, and Al. The results indicate that the SOM concentration gradually decreased with depth, while Fe and Mn were reductively leached from the upper horizons and accumulated significantly in the lower argillic horizons. Atmospheric Pb and Hg deposition and their redistribution during the pedogenic process led to a unique vertical distribution in the wetland Argialbolls. Overall, Pb was leached from the upper horizons and then accumulated in the lower argillic horizons. However, the Hg concentration decreased with depth, following the SOM distribution. The Pb concentration was significantly correlated to the Fe and Mn concentrations in the Argialbolls profiles, while the Hg concentration was significantly correlated with SOM. Post-depositional mobility along the wetland Argialbolls profile is higher for Pb and low for Hg. Therefore, the Argialbolls profile does not provide an accurate reconstruction of atmospheric Pb deposition, but might provide an accurate reconstruction of net atmospheric Hg deposition. PMID:25894341

  6. Vertical Distribution of Lead and Mercury in the Wetland Argialbolls of the Sanjiang Plain in Northeastern China.

    PubMed

    Lin, Chunye; Li, Peizhong; Cheng, Hongguang; Ouyang, Wei

    2015-01-01

    The wetland Argialbolls pedon was chosen to investigate the effects of pedogenic processes and anthropogenic activities on the vertical distribution of lead and mercury concentration and to assess the potential use of soil as an archive of atmospheric Pb and Hg pollution. The soil was sampled from 5 cm from the surface to a depth of 90 cm at two locations in the Sanjiang Plain in northeastern China. The soil was analyzed for pH, soil organic matter (SOM), Fe, Mn, and Al. The results indicate that the SOM concentration gradually decreased with depth, while Fe and Mn were reductively leached from the upper horizons and accumulated significantly in the lower argillic horizons. Atmospheric Pb and Hg deposition and their redistribution during the pedogenic process led to a unique vertical distribution in the wetland Argialbolls. Overall, Pb was leached from the upper horizons and then accumulated in the lower argillic horizons. However, the Hg concentration decreased with depth, following the SOM distribution. The Pb concentration was significantly correlated to the Fe and Mn concentrations in the Argialbolls profiles, while the Hg concentration was significantly correlated with SOM. Post-depositional mobility along the wetland Argialbolls profile is higher for Pb and low for Hg. Therefore, the Argialbolls profile does not provide an accurate reconstruction of atmospheric Pb deposition, but might provide an accurate reconstruction of net atmospheric Hg deposition.

  7. Anthropogenic host plant expansion leads a nettle-feeding butterfly out of the forest: consequences for larval survival and developmental plasticity in adult morphology

    PubMed Central

    Merckx, Thomas; Serruys, Mélanie; Van Dyck, Hans

    2015-01-01

    Recent anthropogenic eutrophication has meant that host plants of nettle-feeding insects became quasi-omnipresent in fertile regions of Western Europe. However, host plant resource quality – in terms of microclimate and nutritional value – may vary considerably between the ‘original’ forest habitat and ‘recent’ agricultural habitat. Here, we compared development in both environmental settings using a split-brood design, so as to explore to what extent larval survival and adult morphology in the nettle-feeding butterfly Aglais urticae are influenced by the anthropogenic environment. Nettles along field margins had higher C/N ratios and provided warmer microclimates to larvae. Larvae developed 20% faster and tended to improve their survival rates, on the agricultural land compared to woodland. Our split-brood approach indicated plastic responses within families, but also family effects in the phenotypic responses. Adult males and females had darker wing pigmentation in the drier and warmer agricultural environment, which contrasts with the thermal melanism hypothesis. Developmental plasticity in response to this microclimatically different and more variable habitat was associated with a broader phenotypic parameter space for the species. Both habitat expansion and developmental plasticity are likely contributors to the ecological and evolutionary success of these nettle-feeding insects in anthropogenic environments under high nitrogen load. PMID:25926881

  8. Anthropogenic host plant expansion leads a nettle-feeding butterfly out of the forest: consequences for larval survival and developmental plasticity in adult morphology.

    PubMed

    Merckx, Thomas; Serruys, Mélanie; Van Dyck, Hans

    2015-04-01

    Recent anthropogenic eutrophication has meant that host plants of nettle-feeding insects became quasi-omnipresent in fertile regions of Western Europe. However, host plant resource quality - in terms of microclimate and nutritional value - may vary considerably between the 'original' forest habitat and 'recent' agricultural habitat. Here, we compared development in both environmental settings using a split-brood design, so as to explore to what extent larval survival and adult morphology in the nettle-feeding butterfly Aglais urticae are influenced by the anthropogenic environment. Nettles along field margins had higher C/N ratios and provided warmer microclimates to larvae. Larvae developed 20% faster and tended to improve their survival rates, on the agricultural land compared to woodland. Our split-brood approach indicated plastic responses within families, but also family effects in the phenotypic responses. Adult males and females had darker wing pigmentation in the drier and warmer agricultural environment, which contrasts with the thermal melanism hypothesis. Developmental plasticity in response to this microclimatically different and more variable habitat was associated with a broader phenotypic parameter space for the species. Both habitat expansion and developmental plasticity are likely contributors to the ecological and evolutionary success of these nettle-feeding insects in anthropogenic environments under high nitrogen load. PMID:25926881

  9. Mineralogical and Molecular Microbial Characterization of a Lead Pipe Removed from a Drinking Water Distribution System

    EPA Science Inventory

    The U.S. Environmental Protection Agency's (US EPA) Lead and Copper Rule established an action level for lead of 0.0 15 mg/L in a 1 liter first draw sample at the consumer's tap. Lead corrosion and solubility in drinking water distribution systems are largely controlled by the fo...

  10. Distribution of chemical elements in attic dust as reflection of their geogenic and anthropogenic sources in the vicinity of the copper mine and flotation plant.

    PubMed

    Balabanova, Biljana; Stafilov, Trajče; Sajn, Robert; Bačeva, Katerina

    2011-08-01

    The main aim of this article was to assess the atmospheric pollution with heavy metals due to copper mining Bučim near Radoviš, the Republic of Macedonia. The open pit and mine waste and flotation tailings are continually exposed to open air, which leads to winds carrying the fine particles into the atmosphere. Samples of attic dust were examined as historical archives of mine emissions, with the aim of elucidating the pathways of pollution. Dust was collected from the attics of 29 houses, built between 1920 and 1970. Nineteen elements (Ag, Al, As, Ba, Ca, Cd, Co, Cr, Cu, Li, Fe, K, Mg, Mn, Na, Ni, Pb, Sr, and Zn) were analyzed by atomic emission spectrometry with inductively coupled plasma. The obtained values of the investigated elements in attic dust samples were statistically processed using nonparametric and parametric analysis. Factor analysis revealed three factors governing the source of individual chemical elements. Two of them grouping Ca, Li, Mg, Mn, and Sr (Factor 1) and Co, Cr, and Ni (Factor 2) can be characterized as geogenic. The third factor grouping As, Cu, and Pb is anthropogenic and mirrors dust fallout from mining operation and from flotation tailings. Maps of areal deposition were prepared for this group of elements, from which correlation of these anthropogenic born elements was confirmed.

  11. Are anthropogenic aerosols affecting rainfall?

    NASA Astrophysics Data System (ADS)

    Junkermann, Wolfgang; Hacker, Jorg

    2013-04-01

    Modification of cloud microphysics by anthropogenic aerosols is well known since several decades. Whether the underlying processes leads to changes in precipitation is by far less confirmed. Several different factors affect the production of rain in a way that a causality between increasing aerosol load in the atmosphere and a change of annual rainfall is very difficult to confirm. What would be expected as an effect of additional cloud condensation nuclei is a shift in the spatial and temporal rainfall distribution towards a lower number of days with low rain intensity and more frequent or more vigorous single events. In fact such a shift has been observed in several locations worldwide and has been suggested to be caused by increasing aerosol load, however, without further specification of the nature and number of the aerosols involved. Measurements of aerosols which might be important for cloud properties are extremely sparse and no long term monitoring data sets are available up to now. The problem of missing long term aerosol data that could be compared to available long term meteorological data sets can possibly be resolved in certain areas where well characterized large anthropogenic aerosol sources were installed in otherwise pristine areas without significant changes in land use over several decades. We investigated aerosol sources and current aerosol number, size and spatial distributions with airborne measurements in the planetary boundary layer over two regions in Australia that are reported to suffer from extensive drought despite the fact that local to regional scale water vapor in the atmosphere is slowly and constantly increasing. Such an increase of the total water in the planetary boundary layer would imply also an increase in annual precipitation as observed in many other locations elsewhere. The observed decline of rainfall in these areas thus requires a local to regional scale physical process modifying cloud properties in a way that rain

  12. Probable errors in width distributions of sea ice leads measured along a transect

    NASA Technical Reports Server (NTRS)

    Key, J.; Peckham, S.

    1991-01-01

    The degree of error expected in the measurement of widths of sea ice leads along a single transect are examined in a probabilistic sense under assumed orientation and width distributions, where both isotropic and anisotropic lead orientations are examined. Methods are developed for estimating the distribution of 'actual' widths (measured perpendicular to the local lead orientation) knowing the 'apparent' width distribution (measured along the transect), and vice versa. The distribution of errors, defined as the difference between the actual and apparent lead width, can be estimated from the two width distributions, and all moments of this distribution can be determined. The problem is illustrated with Landsat imagery and the procedure is applied to a submarine sonar transect. Results are determined for a range of geometries, and indicate the importance of orientation information if data sampled along a transect are to be used for the description of lead geometries. While the application here is to sea ice leads, the methodology can be applied to measurements of any linear feature.

  13. Microbial community profile of a lead service line removed from a drinking water distribution system.

    PubMed

    White, Colin; Tancos, Matthew; Lytle, Darren A

    2011-08-01

    A corroded lead service line was removed from a drinking water distribution system, and the microbial community was profiled using 16S rRNA gene techniques. This is the first report of the characterization of a biofilm on the surface of a corroded lead drinking water service line. The majority of phylotypes have been linked to heavy-metal-contaminated environments.

  14. Microbial Community Profile of a Lead Service Line Removed from a Drinking Water Distribution System

    EPA Science Inventory

    A corroded lead water pipe was removed from a drinking water distribution system and the microbial community was profiled using 16S rDNA techniques. This is the first report of the characterization of biofilm on a surface of a corroded lead drinking water pipe. The majority of ...

  15. Recent distribution of lead in the Indian Ocean reflects the impact of regional emissions

    NASA Astrophysics Data System (ADS)

    Echegoyen, Yolanda; Boyle, Edward A.; Lee, Jong-Mi; Gamo, Toshitaka; Obata, Hajime; Norisuye, Kazuhiro

    2014-10-01

    Humans have injected lead (Pb) massively into the earth surface environment in a temporally and spatially evolving pattern. A significant fraction is transported by the atmosphere into the surface ocean where we can observe its transport by ocean currents and sinking particles. This study of the Indian Ocean documents high Pb concentrations in the northern and tropical surface waters and extremely low Pb levels in the deep water. North of 20°S, dissolved Pb concentrations decrease from 42 to 82 pmol/kg in surface waters to 1.5-3.3 pmol/kg in deep waters. South of 20°S, surface water Pb concentrations decrease from 21 pmol/kg at 31°S to 7 pmol/kg at 62°S. This surface Pb concentration gradient reflects a southward decrease in anthropogenic Pb emissions. The upper waters of the north and central Indian Ocean have high Pb concentrations resulting from recent regional rapid industrialization and a late phase-out of leaded gasoline, and these concentrations are now higher than currently seen in the central North Pacific and North Atlantic oceans. The Antarctic sector of the Indian Ocean shows very low concentrations due to limited regional anthropogenic Pb emissions, high scavenging rates, and rapid vertical mixing, but Pb still occurs at higher levels than would have existed centuries ago. Penetration of Pb into the northern and central Indian Ocean thermocline waters is minimized by limited ventilation. Pb concentrations in the deep Indian Ocean are comparable to the other oceans at the same latitude, and deep waters of the central Indian Ocean match the lowest observed oceanic Pb concentrations.

  16. Recent distribution of lead in the Indian Ocean reflects the impact of regional emissions.

    PubMed

    Echegoyen, Yolanda; Boyle, Edward A; Lee, Jong-Mi; Gamo, Toshitaka; Obata, Hajime; Norisuye, Kazuhiro

    2014-10-28

    Humans have injected lead (Pb) massively into the earth surface environment in a temporally and spatially evolving pattern. A significant fraction is transported by the atmosphere into the surface ocean where we can observe its transport by ocean currents and sinking particles. This study of the Indian Ocean documents high Pb concentrations in the northern and tropical surface waters and extremely low Pb levels in the deep water. North of 20°S, dissolved Pb concentrations decrease from 42 to 82 pmol/kg in surface waters to 1.5-3.3 pmol/kg in deep waters. South of 20°S, surface water Pb concentrations decrease from 21 pmol/kg at 31°S to 7 pmol/kg at 62°S. This surface Pb concentration gradient reflects a southward decrease in anthropogenic Pb emissions. The upper waters of the north and central Indian Ocean have high Pb concentrations resulting from recent regional rapid industrialization and a late phase-out of leaded gasoline, and these concentrations are now higher than currently seen in the central North Pacific and North Atlantic oceans. The Antarctic sector of the Indian Ocean shows very low concentrations due to limited regional anthropogenic Pb emissions, high scavenging rates, and rapid vertical mixing, but Pb still occurs at higher levels than would have existed centuries ago. Penetration of Pb into the northern and central Indian Ocean thermocline waters is minimized by limited ventilation. Pb concentrations in the deep Indian Ocean are comparable to the other oceans at the same latitude, and deep waters of the central Indian Ocean match the lowest observed oceanic Pb concentrations.

  17. Distribution and transport of selected anthropogenic lipophilic organic compounds associated with Mississippi River suspended sediment, 1989-1990

    USGS Publications Warehouse

    Rostad, C.E.; Pereira, W.E.; Leiker, T.J.

    1999-01-01

    In the first study on this scale, distribution and transport of selected hydrophobic halogenated organic compounds associated with suspended sediment from the lower Mississippi River and its principal tributaries were determined during two spring and two summer cruises. Lipophilic organic compounds identified on the suspended sediment included hexachlorobenzene, pentachlorobenzene, pentachloroanisole, dacthal, chlordane (cis- and trans- ), nonachlor (trans-), chlorthalonil, and penta-, hexa-, hepta-, and octachlorobiphenyls. Most of these compounds come from nonpoint sources. Mass loadings of most of the compounds increased from upstream to downstream on the main stem of the Mississippi River. Of the tributaries studied, the Ohio River had the most significant effect on contaminant loads. Suspended sediment transport to the Gulf of Mexico of the most abundant, widely distributed compound class, PCBs, was estimated at 6,750 kg per year.

  18. Impacts of blending ground, surface, and saline waters on lead release in drinking water distribution systems.

    PubMed

    Tang, Zhijian; Hong, Seungkwan; Xiao, Weizhong; Taylor, James

    2006-03-01

    The impacts of distribution water quality changes caused by blending different source waters on lead release from corrosion loops containing small lead coupons were investigated in a pilot distribution study. The 1-year pilot study demonstrated that lead release to drinking water increased as chlorides increased and sulfates decreased. Silica and calcium inhibited lead release to a lesser degree than sulfates. An additional 3-month field study isolated and verified the effects of chlorides and sulfates on lead release. Lead release decreased with increasing pH and increasing alkalinity during the 1-year pilot study; however, the effects of pH and alkalinity on lead release, were not clearly elucidated due to confounding effects. A statistical model was developed using nonlinear regression, which showed that lead release increased with increasing chlorides, alkalinity and temperature, and decreased with increasing pH and sulfates. The model indicated that primary treatment processes such as enhanced coagulation and RO (reverse osmosis membrane) were related to lead release by water quality. Chlorides are high in RO-finished water and increase lead release, while sulfates are high following enhanced coagulation and decrease lead release.

  19. The influence of climate change on the global distribution and fate processes of anthropogenic persistent organic pollutants.

    PubMed

    Kallenborn, Roland; Halsall, Crispin; Dellong, Maud; Carlsson, Pernilla

    2012-11-01

    The effect of climate change on the global distribution and fate of persistent organic pollutants (POPs) is of growing interest to both scientists and policy makers alike. The impact of warmer temperatures and the resulting changes to earth system processes on chemical fate are, however, unclear, although there are a growing number of studies that are beginning to examine these impacts and changes in a quantitative way. In this review, we examine broad areas where changes are occurring or are likely to occur with regard to the environmental cycling and fate of chemical contaminants. For this purpose we are examining scientific information from long-term monitoring data with particular emphasis on the Arctic, to show apparent changes in chemical patterns and behaviour. In addition, we examine evidence of changing chemical processes for a number of environmental compartments and indirect effects of climate change on contaminant emissions and behaviour. We also recommend areas of research to address knowledge gaps. In general, our findings indicate that the indirect consequences of climate change (i.e. shifts in agriculture, resource exploitation opportunities, etc.) will have a more marked impact on contaminants distribution and fate than direct climate change. PMID:23014859

  20. Distribution and assessment of heavy metals off the Changjiang River mouth and adjacent area during the past century and the relationship of the heavy metals with anthropogenic activity.

    PubMed

    Hu, Gang; Bi, Shipu; Xu, Gang; Zhang, Yong; Mei, Xi; Li, Anchun

    2015-07-15

    Forty-three surface sediment samples and one gravity core obtained from the offshore area of the Changjiang River were analyzed for selected heavy metals (Cu, Pb, Zn, Cd, As, Hg) to evaluate the spatial distribution and potential ecological risk during the last century. The results indicated that the sediments are composed of silty sand, sandy silt and silt and were deposited in a relatively stable environment over the last century. The studied marine sediments are fine and easily adsorb heavy metals from aquatic systems. The heavy metal concentrations were found to be enriched in the sediments and were generally closely related to anthropogenic activities. However, the data analysis demonstrated that the levels of heavy metal contamination were below background values during the last century, indicating low ecological risk. Spatially, a higher concentration was found at the entrance to the Changjiang River, while it decreased to the northeast. The vertical distribution of contamination levels and ecological risk can be divided into four periods based on the downcore variation in heavy metals: pre-1940s, 1940s-1970s, 1970s-1990s and the late 1990s to the present. These conclusions form the basis for implementing appropriate policies to protect marine sediment quality. PMID:26002099

  1. A lead isotope distribution study in swine tissue using ICP-MS

    USGS Publications Warehouse

    May, T.W.; Wiedmeyer, Ray H.; Brown, L.D.; Casteel, S.W.

    1999-01-01

    In the United States lead is an ubiquitous environmental pollutant that is a serious human health hazard, especially for women of childbearing age, developing fetuses, and young children. Information concerning the uptake and distribution of lead to maternal and fetal tissues during pregnancy is poorly documented. A study was designed using domestic swine and lead isotope enrichment methodology to focus on maternal absorption and distribution of lead into bone and soft tissues, including the fetal compartment, under varying conditions of oral lead exposure and during altered physiological states (pregnant vs unbred). Total lead levels and Pb207/Pb206 ratios in bone (femur and vertebra), blood, and soft tissues (liver, kidney, brain) were determined by ICP-MS. Lead in fetal tissues derived from maternal bone could be differentiated from that derived from exogenous dosing. Unbred swine absorbed much less lead than pregnant females receiving the same dose. The accuracy and precision of ICP-MS at the instrumental level and for the entire method (sample collection, digestion, and analysis) were evaluated for both Pb207/Pb206 ratios and total lead. Several changes were suggested in method design to improve both instrumental and total method precision.

  2. The impact of detailed urban-scale processing on the composition, distribution, and radiative forcing of anthropogenic aerosols

    NASA Astrophysics Data System (ADS)

    Cohen, Jason Blake; Prinn, Ronald G.; Wang, Chien

    2011-05-01

    Detailed urban-scale processing has not been included in global 3D chemical transport models due to its large computational demands. Here we present a metamodel for including this processing, and compare it with the use of the traditional approach of dilution of emissions into large grid boxes. This metamodel is used in a global 3D model to simulate the effects of cities around the world on aerosol chemistry, physics, and radiative effects at the global scale. We show that the biases caused by ignoring urban processing on the global values of total aerosol surface concentration, the total aerosol column abundance, the aerosol optical depth (AOD), the absorbing aerosol optical depth (AAOD), and the top of the atmosphere radiative forcing (TOA) respectively are +26 ± 32%, +51 ± 1012%, +42 ± 810%, +8 ± 1618%, and -0.27 ± 0.140.10 W/m2. These results show that failure to consider urban scale processing leads to significantly more negative aerosol radiative forcing compared to when detailed urban scale processing is considered.

  3. Asymmetric distribution of Echinoid defines the epidermal leading edge during Drosophila dorsal closure

    PubMed Central

    Laplante, Caroline

    2011-01-01

    During Drosophila melanogaster dorsal closure, lateral sheets of embryonic epidermis assemble an actomyosin cable at their leading edge and migrate dorsally over the amnioserosa, converging at the dorsal midline. We show that disappearance of the homophilic cell adhesion molecule Echinoid (Ed) from the amnioserosa just before dorsal closure eliminates homophilic interactions with the adjacent dorsal-most epidermal (DME) cells, which comprise the leading edge. The resulting planar polarized distribution of Ed in the DME cells is essential for the localized accumulation of actin regulators and for actomyosin cable formation at the leading edge and for the polarized localization of the scaffolding protein Bazooka/PAR-3. DME cells with uniform Ed fail to assemble a cable and protrude dorsally, suggesting that the cable restricts dorsal migration. The planar polarized distribution of Ed in the DME cells thus provides a spatial cue that polarizes the DME cell actin cytoskeleton, defining the epidermal leading edge and establishing its contractile properties. PMID:21263031

  4. Influence of leads widths distribution on turbulent heat transfer between the ocean and the atmosphere

    NASA Astrophysics Data System (ADS)

    Marcq, S.; Weiss, J.

    2011-10-01

    Leads are linear-like structures of open water within the sea ice cover that develop as the result of fracturing due to divergence or shear. Through leads, air and water come into contact and directly exchange latent and sensible heat through convective processes driven by the large temperature and moisture differences between them. In the central Arctic, leads only cover 1 to 2% of the ocean during winter, but account for more than 80% of the heat fluxes. Furthermore, narrow leads (several meters) are more than twice as efficient at transmitting turbulent heat than larger ones (several hundreds of meters). We show that lead widths are power law distributed, P(X)~X-a with a>1, down to very small spatial scales (20 m or below). This implies that the open water fraction is by far dominated by very small leads. Using two classical formulations, which provide first order turbulence closure for the fetch-dependence of heat fluxes, we find that the mean heat fluxes (sensible and latent) over open water are up to 55 % larger when considering the lead width distribution obtained from a SPOT satellite image of the ice cover, compared to the situation where the open water fraction constitutes one unique large lead and the rest of the area is covered by ice, as it is usually considered in climate models at the grid scale. This difference may be even larger if we assume that the power law scaling of lead widths extents down to smaller (~1 m) scales. Such estimations may be a first step towards a subgrid scale parameterization of the spatial distribution of open water for heat fluxes calculations in ocean/sea ice coupled models.

  5. Distribution of lead in biotic and abiotic media associated with a military shooting range

    SciTech Connect

    Petroff, D.M.; Mahoney, L.A.; Pintenich, J.L.

    1995-12-31

    A comprehensive investigation was conducted at a military shooting range to characterize the distribution and potential toxicity of lead from shot deposited at the site over many years. Site biota (vegetation and small mammals), soils, surface water, and groundwater were collected and analyzed for total lead concentrations. Acute terrestrial and acute and chronic aquatic toxicity tests were performed on site soils and water samples, respectively. Results of the investigation indicated that surface water was not impacted by lead. Lead was detected in groundwater in concentrations up to 159 {micro}g/L, and was shown to cause chronic toxicity effects in test organisms. Site soils had lead concentrations up to 31,000 mg/kg, and lead was found above background in the deepest soil samples collected (12 to 24 inches). Toxicity was noted in the majority of soil samples analyzed. Lead was also detected in site vegetation (foliar portions) at levels above background, and in small mammals, but at fairly low concentrations (up to 4 mg/kg). As a relative indicator of the degree of transfer of lead between the site media evaluated, a series of concentration ratios were calculated. As a result, the ranking of the transfer of lead between site media appeared to be (in descending order): (1) surficial soil to roots; (2) surficial soil to subsurface soil; (3) vegetation (foliar) to mammals; (4) roots to vegetation (foliar); (5) surficial soil to vegetation (foliar); (6) surficial soil to mammals; and (7) subsurface soil to groundwater.

  6. Next-to-Leading Order QCD Predictions for Z, gamma^* 3-Jet Distributions at the Tevatron

    SciTech Connect

    Berger, C.F.; Bern, Z.; Dixon, L.J.; Cordero, F.Febres; Forde, D.; Gleisberg, T.; Ita, H.; Kosower, D.A.; Maitre, D.; /Durham U.

    2010-06-02

    Using BlackHat in conjunction with SHERPA, we have computed next-to-leading order QCD predictions for a variety of distributions in Z, {gamma}{sup {asterisk}}+ 1, 2, 3-jet production at the Tevatron, where the Z boson or off-shell photon decays into an electron-positron pair. We find good agreement between the NLO results for jet {sub pT} distributions and measurements by CDF and D0. We also present jetproduction ratios, or probabilities of finding one additional jet. As a function of vector-boson {sub pT} , the ratios have distinctive features which we describe in terms of a simple model capturing leading logarithms and phase-space and parton-distribution-function suppression.

  7. A new analytical approach to understanding nanoscale lead-iron interactions in drinking water distribution systems.

    PubMed

    Trueman, Benjamin F; Gagnon, Graham A

    2016-07-01

    High levels of iron in distributed drinking water often accompany elevated lead release from lead service lines and other plumbing. Lead-iron interactions in drinking water distribution systems are hypothesized to be the result of adsorption and transport of lead by iron oxide particles. This mechanism was explored using point-of-use drinking water samples characterized by size exclusion chromatography with UV and multi-element (ICP-MS) detection. In separations on two different stationary phases, high apparent molecular weight (>669 kDa) elution profiles for (56)Fe and (208)Pb were strongly correlated (average R(2)=0.96, N=73 samples representing 23 single-unit residences). Moreover, (56)Fe and (208)Pb peak areas exhibited an apparent linear dependence (R(2)=0.82), consistent with mobilization of lead via adsorption to colloidal particles rich in iron. A UV254 absorbance peak, coincident with high molecular weight (56)Fe and (208)Pb, implied that natural organic matter was interacting with the hypothesized colloidal species. High molecular weight UV254 peak areas were correlated with both (56)Fe and (208)Pb peak areas (R(2)=0.87 and 0.58, respectively). On average, 45% (std. dev. 10%) of total lead occurred in the size range 0.05-0.45 μm.

  8. Anthropogenic dissolved and colloid/nanoparticle-bound samarium, lanthanum and gadolinium in the Rhine River and the impending destruction of the natural rare earth element distribution in rivers

    NASA Astrophysics Data System (ADS)

    Kulaksız, Serkan; Bau, Michael

    2013-01-01

    The strong increase in the consumption of rare earth elements (REE) in high-tech products and processes is accompanied by increasing amounts of REE released into the environment. Following the first report of Gd contamination of the hydrosphere in 1996, anthropogenic Gd originating from contrast agents has now been reported worldwide from river and estuarine waters, coastal seawater, groundwater and tap water. Recently, microcontamination with La, that is derived from a point source where catalysts for petroleum refining are produced, has been detected in the Rhine River in Germany and the Netherlands. Here we report the occurrence of yet another REE microcontamination of river water: in addition to anthropogenic Gd and La, the Rhine River now also shows significant amounts of anthropogenic Sm. The anthropogenic Sm, which enters the Rhine River north of Worms, Germany, with the same industrial wastewater that carries the anthropogenic La, can be traced through the Middle and Lower Rhine to the Netherlands. At Leverkusen, Germany, some 250 km downstream from the point source at Worms, anthropogenic Sm still contributes up to 87% of the total dissolved Sm concentration of the Rhine River. Results from ultrafiltration suggest that while the anthropogenic Gd is not particle-reactive and hence exclusively present in the truly dissolved REE pool (<10 kDa), the anthropogenic La and Sm are also present in the colloidal/nanoparticulate REE pool (between 10 kDa and 0.2 μm). Though difficult to quantify, our data suggest that the Rhine River may carry up to 5700 kg of anthropogenic La, up to 584 kg of anthropogenic Sm, and up to 730 kg of anthropogenic Gd per year toward the North Sea. There exist no regulatory limits for dissolved REE in natural waters, but total REE and Y (∑REY) concentrations of up to 0.14 mg/kg in the plume downstream of and 52.2 mg/kg at the head of an effluent pipe at Rhine-km 447.3 at Worms get close to and well-above, respectively, the levels at

  9. Determination of nuclear parton distribution functions and their uncertainties at next-to-leading order

    SciTech Connect

    Hirai, M.; Kumano, S.; Nagai, T.-H.

    2007-12-15

    Nuclear parton distribution functions (NPDFs) are determined by global analyses of experimental data on structure-function ratios F{sub 2}{sup A}/F{sub 2}{sup A'} and Drell-Yan cross-section ratios {sigma}{sub DY}{sup A}/{sigma}{sub DY}{sup A'}. The analyses are done in the leading order (LO) and next-to-leading order (NLO) of running coupling constant {alpha}{sub s}. Uncertainties of the NPDFs are estimated in both LO and NLO for finding possible NLO improvement. Valence-quark distributions are well determined, and antiquark distributions are also determined at x<0.1. However, the antiquark distributions have large uncertainties at x>0.2. Gluon modifications cannot be fixed at this stage. Although the advantage of the NLO analysis, in comparison with the LO one, is generally the sensitivity to the gluon distributions, gluon uncertainties are almost the same in the LO and NLO. It is because current scaling-violation data are not accurate enough to determine precise nuclear gluon distributions. Modifications of the PDFs in the deuteron are also discussed by including data on the proton-deuteron ratio F{sub 2}{sup D}/F{sub 2}{sup p} in the analysis. A code is provided for calculating the NPDFs and their uncertainties at given x and Q{sup 2} in the LO and NLO.

  10. Spherical particles and voids effect on current and potential distribution in integrated circuit leads

    NASA Astrophysics Data System (ADS)

    Pang, Dongqing; Sun, Yicai

    2015-06-01

    Relationships of resistance with a width of 0.1 μm for different heights and currents at a given volt drop are plotted for a 0.2 μm length smooth copper lead. The lead is specified to connect with the integrated circuit AD8622 with its Isr = 0.350 mA to determine the volt drop = 0.2 mV. The total current is computed according to the total resistance of the lead for the different void radius at this volt drop. The current density value at the right boundary is determined by Ohm’s law. After combining the integration of the total current as a prerequisite with the interpolation of current density values from the left, i.e. void edge to the right boundaries, their distribution is obtained, showing current crowding outside of their edges and a great resistance with the increase of their radius. The calculation errors for comparison with the Laplace equation are calculated, mainly located on the corners of void. The potential distribution can be obtained by multiplying sheet resistance to current density distribution. At last, the relationship between resistance, total current, current crowding and calculation errors with the different void radius and lead length are offered in several forms for use in the integrated circuit design.

  11. Multivariate spatial analyses of the distribution and origin of trace and major elements in soils surrounding a secondary lead smelter.

    PubMed

    Schneider, Arnaud R; Morvan, Xavier; Saby, Nicolas P A; Cancès, Benjamin; Ponthieu, Marie; Gommeaux, Maxime; Marin, Béatrice

    2016-08-01

    Major and trace elements in soils originate from natural processes and different anthropogenic activities which are difficult to discriminate. On a 17-ha impacted site in northern France, two industrial sources of soil contamination were xidentified: a former iron foundry and a current secondary lead smelter. To discriminate and map natural and anthropogenic sources of major and trace elements on this site, the rarely applied MULTISPATI-principal component analysis (PCA) method was used. Using a 20-m × 20-m grid, 247 topsoil horizons were sampled and analysed with a field-portable X-ray fluorescence analyser for screening soil contamination. The study site was heavily contaminated with Pb and, to a lesser degree, with Sn. Summary statistics and enrichment factors allowed the differentiation of the main lithogenic or anthropogenic origin of the elements. The MULTISPATI-PCA method, which explained 73.9 % of the variability with the three first factors, evidenced strong spatial structures. Those spatial structures were attributed to different natural and artificial processes in the study area. The first axis can be interpreted as a lithogenic effect. Axes 2 and 3 reflect the two different contamination sources. Pb, Sn and S originated from the secondary lead smelter while Fe and Ca were mainly derived from the old iron foundry activity and the old railway built with foundry sand. This study demonstrated that the MULTISPATI-PCA method can be successfully used to investigate multicontaminated sites to discriminate the various sources of contamination.

  12. Multivariate spatial analyses of the distribution and origin of trace and major elements in soils surrounding a secondary lead smelter.

    PubMed

    Schneider, Arnaud R; Morvan, Xavier; Saby, Nicolas P A; Cancès, Benjamin; Ponthieu, Marie; Gommeaux, Maxime; Marin, Béatrice

    2016-08-01

    Major and trace elements in soils originate from natural processes and different anthropogenic activities which are difficult to discriminate. On a 17-ha impacted site in northern France, two industrial sources of soil contamination were xidentified: a former iron foundry and a current secondary lead smelter. To discriminate and map natural and anthropogenic sources of major and trace elements on this site, the rarely applied MULTISPATI-principal component analysis (PCA) method was used. Using a 20-m × 20-m grid, 247 topsoil horizons were sampled and analysed with a field-portable X-ray fluorescence analyser for screening soil contamination. The study site was heavily contaminated with Pb and, to a lesser degree, with Sn. Summary statistics and enrichment factors allowed the differentiation of the main lithogenic or anthropogenic origin of the elements. The MULTISPATI-PCA method, which explained 73.9 % of the variability with the three first factors, evidenced strong spatial structures. Those spatial structures were attributed to different natural and artificial processes in the study area. The first axis can be interpreted as a lithogenic effect. Axes 2 and 3 reflect the two different contamination sources. Pb, Sn and S originated from the secondary lead smelter while Fe and Ca were mainly derived from the old iron foundry activity and the old railway built with foundry sand. This study demonstrated that the MULTISPATI-PCA method can be successfully used to investigate multicontaminated sites to discriminate the various sources of contamination. PMID:27094274

  13. Estuarine distributions of Zr, Hf, and Ag in the Hudson River and the implications for their continental and anthropogenic sources to seawater

    NASA Astrophysics Data System (ADS)

    Godfrey, L. V.; Field, M. P.; Sherrell, R. M.

    2008-12-01

    Zirconium and Hf in seawater are derived from continental weathering and are transported to the oceans by rivers, but the modification of this flux with estuaries is largely unknown. Furthermore, there is no information as to whether there is a pollutant source of these metals that might affect their budget calculations in the modern ocean. To address the riverine flux and potential anthropogenic sources, the distributions of dissolved Zr and Hf have been measured in surface and bottom water through the Hudson River Estuary. The distribution of Ag is included because it is sensitive to urban sources and has partial similarities in its distribution to those of Zr and Hf. There is about 50% removal of Zr and Hf in surface water relative to their freshwater end-member concentrations of 243 and 3.1 pmol/kg as salinity starts to increase, but an urban source of these metals midestuary may obscure greater removal. Silver concentrations in surface water are below the detection limit until salinity of 3.5 is reached. The concentrations of Zr and Hf 0.5 m above the bottom are 1.5 to 3 times higher than their surface water concentrations throughout the estuary and may result from input of groundwater, diffusion from pore fluids, or inclusion of colloidal phases in our analyses. Downstream of the turbidity maximum, bottom water Ag concentrations are high due to release from particles that originally formed within the estuary and were moved inland following the spring freshet; this process may also affect Zr and Hf. The increase in the freshwater atomic Zr/Hf ratio from 70 to 80, characteristic of terrestrial rocks, to the elevated Zr/Hf (>110) ratio of seawater takes place at middle to high salinity due to enhanced release of Zr from resuspended particles and slower removal rates compared to Hf. A main implication of this study is that estuaries are a sink for Zr and Hf. The reduction of the predicted export of continental Zr and Hf to the oceans increases their previously

  14. Distribution of biologic, anthropogenic, and volcanic constituents as a proxy for sediment transport in the San Francisco Bay coastal system, California

    NASA Astrophysics Data System (ADS)

    McGann, M.; Erikson, L. H.; Wan, E.; Powell, C., II; Maddocks, R. F.

    2012-12-01

    The biological, anthropogenic, and volcanic constituents of more than 300 samples collected from 1995 to 2010 in San Francisco Bay and the nearby coastal area were analyzed to discern patterns of sediment transport and deposition. The biological constituents investigated include microfauna (benthic and planktic foraminifers, ostracods, radiolarians, diatoms, and thecamoebians), macrofauna (bivalve mollusks, gastropods, barnacles, bryozoa, worm tubes, echinoids, crabs, and fish fragments), and flora (woody stems, roots, spores, and seeds). The distributional pattern of the benthic foraminifers was further refined by Q-mode cluster analysis into four assemblages that reflect where the taxa reside: the Brackish Shallow Subtidal Assemblage, the Estuarine Shallow Subtidal Assemblage, the Estuarine Intermediate/Deep Subtidal Assemblage, and the Nearshore Marine Assemblage. The anthropogenic objects recovered in this study include welding slag and glass microspheres most likely used to increase roadway line reflectivity. The volcanic constituents are glass shards of the Pliocene (3.27 Ma) Nomlaki Tuff, and Miocene tephra mostly derived from the Great Central Valley (including from the 23-19 Ma Valley Springs Formation, among others) and from the Sonoma Volcanic Field of California. The presence of allochthonous sedimentological constituents in this study was used to identify pathways of sediment transport and deposition within the San Francisco Bay coastal system. Several patterns have been identified: 1) volcanic glass shards are transported from the Great Central Valley through the delta to all regions of the bay, including the extreme end of south bay, as well as along the coast outside the bay and southward to Pedro Point; 2) microorganisms (benthic and planktic foraminifers, ostracods, diatoms, and radiolaria) from the marine realm outside San Francisco Bay are found in the estuary at the southern end of south bay, commonly in the middle of San Pablo Bay, and

  15. Colonization History, Host Distribution, Anthropogenic Influence and Landscape Features Shape Populations of White Pine Blister Rust, an Invasive Alien Tree Pathogen

    PubMed Central

    Brar, Simren; Tsui, Clement K. M.; Dhillon, Braham; Bergeron, Marie-Josée; Joly, David L.; Zambino, P. J.; El-Kassaby, Yousry A.; Hamelin, Richard C.

    2015-01-01

    White pine blister rust is caused by the fungal pathogen Cronartium ribicola J.C. Fisch (Basidiomycota, Pucciniales). This invasive alien pathogen was introduced into North America at the beginning of the 20th century on pine seedlings imported from Europe and has caused serious economic and ecological impacts. In this study, we applied a population and landscape genetics approach to understand the patterns of introduction and colonization as well as population structure and migration of C. ribicola. We characterized 1,292 samples of C. ribicola from 66 geographic locations in North America using single nucleotide polymorphisms (SNPs) and evaluated the effect of landscape features, host distribution, and colonization history on the structure of these pathogen populations. We identified eastern and western genetic populations in North America that are strongly differentiated. Genetic diversity is two to five times higher in eastern populations than in western ones, which can be explained by the repeated accidental introductions of the pathogen into northeastern North America compared with a single documented introduction into western North America. These distinct genetic populations are maintained by a barrier to gene flow that corresponds to a region where host connectivity is interrupted. Furthermore, additional cryptic spatial differentiation was identified in western populations. This differentiation corresponds to landscape features, such as mountain ranges, and also to host connectivity. We also detected genetic differentiation between the pathogen populations in natural stands and plantations, an indication that anthropogenic movement of this pathogen still takes place. These results highlight the importance of monitoring this invasive alien tree pathogen to prevent admixture of eastern and western populations where different pathogen races occur. PMID:26010250

  16. Colonization history, host distribution, anthropogenic influence and landscape features shape populations of white pine blister rust, an invasive alien tree pathogen.

    PubMed

    Brar, Simren; Tsui, Clement K M; Dhillon, Braham; Bergeron, Marie-Josée; Joly, David L; Zambino, P J; El-Kassaby, Yousry A; Hamelin, Richard C

    2015-01-01

    White pine blister rust is caused by the fungal pathogen Cronartium ribicola J.C. Fisch (Basidiomycota, Pucciniales). This invasive alien pathogen was introduced into North America at the beginning of the 20th century on pine seedlings imported from Europe and has caused serious economic and ecological impacts. In this study, we applied a population and landscape genetics approach to understand the patterns of introduction and colonization as well as population structure and migration of C. ribicola. We characterized 1,292 samples of C. ribicola from 66 geographic locations in North America using single nucleotide polymorphisms (SNPs) and evaluated the effect of landscape features, host distribution, and colonization history on the structure of these pathogen populations. We identified eastern and western genetic populations in North America that are strongly differentiated. Genetic diversity is two to five times higher in eastern populations than in western ones, which can be explained by the repeated accidental introductions of the pathogen into northeastern North America compared with a single documented introduction into western North America. These distinct genetic populations are maintained by a barrier to gene flow that corresponds to a region where host connectivity is interrupted. Furthermore, additional cryptic spatial differentiation was identified in western populations. This differentiation corresponds to landscape features, such as mountain ranges, and also to host connectivity. We also detected genetic differentiation between the pathogen populations in natural stands and plantations, an indication that anthropogenic movement of this pathogen still takes place. These results highlight the importance of monitoring this invasive alien tree pathogen to prevent admixture of eastern and western populations where different pathogen races occur.

  17. Distribution of lead, cadmium, and zinc in tissues of hens and chickens from Slovenia

    SciTech Connect

    Doganoc, D.Z.

    1996-12-01

    Lead (Pb) and cadmium (Cd) are environmental contaminants which are present in almost all living organisms and are non-essential for plants, animals and human beings. Zinc (Zn) is an essential element which occurs together with Cd and is linked with it. Little information exists about the contamination of tissues of hens and chickens with these elements. The primary aim of this study was to investigate the distribution of lead, cadmium, and zinc in different tissues of poultry and eggs in Slovenia. 10 refs., 7 tabs.

  18. Distribution of current in the electrodes of lead-acid batteries: a thermographic analysis approach

    NASA Astrophysics Data System (ADS)

    Streza, M.; Nuţ, C.; Tudoran, C.; Bunea, V.; Calborean, A.; Morari, C.

    2016-02-01

    An experimental method for the investigation of the current distribution in the electrodes of lead-acid batteries has been developed. The information is extracted by analysing the heat dissipation in the electrode during the discharge by using a high-performance IR camera. The effect of the current in the metallic grid can be de-convoluted from the total heat produced in the electrode by numerical processing of the temperature distribution over the electrode surface. By its simplicity and effectiveness, the proposed method has the potential to become an important tool in optimising electrode geometry.

  19. Leading twist nuclear shadowing, nuclear generalized parton distributions and nuclear DVCS at small x

    SciTech Connect

    Guzey, Vadim; Goeke, Klaus; Siddikov, Marat

    2009-01-01

    We generalize the leading twist theory of nuclear shadowing and calculate quark and gluon generalized parton distributions (GPDs) of spinless nuclei. We predict very large nuclear shadowing for nuclear GPDs. In the limit of the purely transverse momentum transfer, our nuclear GPDs become impact parameter dependent nuclear parton distributions (PDFs). Nuclear shadowing induces non-trivial correlations between the impact parameter $b$ and the light-cone fraction $x$. We make predictions for the deeply virtual Compton scattering (DVCS) amplitude and the DVCS cross section on $^{208}$Pb at high energies. We calculate the cross section of the Bethe-Heitler (BH) process and address the issue of the extraction of the DVCS signal from the $e A \\to e \\gamma A$ cross section. We find that the $e A \\to e \\gamma A$ differential cross section is dominated by DVCS at the momentum transfer $t$ near the minima of the nuclear form factor. We also find that nuclear shadowing leads

  20. Confounding environmental colour and distribution shape leads to underestimation of population extinction risk.

    PubMed

    Fowler, Mike S; Ruokolainen, Lasse

    2013-01-01

    The colour of environmental variability influences the size of population fluctuations when filtered through density dependent dynamics, driving extinction risk through dynamical resonance. Slow fluctuations (low frequencies) dominate in red environments, rapid fluctuations (high frequencies) in blue environments and white environments are purely random (no frequencies dominate). Two methods are commonly employed to generate the coloured spatial and/or temporal stochastic (environmental) series used in combination with population (dynamical feedback) models: autoregressive [AR(1)] and sinusoidal (1/f) models. We show that changing environmental colour from white to red with 1/f models, and from white to red or blue with AR(1) models, generates coloured environmental series that are not normally distributed at finite time-scales, potentially confounding comparison with normally distributed white noise models. Increasing variability of sample Skewness and Kurtosis and decreasing mean Kurtosis of these series alter the frequency distribution shape of the realised values of the coloured stochastic processes. These changes in distribution shape alter patterns in the probability of single and series of extreme conditions. We show that the reduced extinction risk for undercompensating (slow growing) populations in red environments previously predicted with traditional 1/f methods is an artefact of changes in the distribution shapes of the environmental series. This is demonstrated by comparison with coloured series controlled to be normally distributed using spectral mimicry. Changes in the distribution shape that arise using traditional methods lead to underestimation of extinction risk in normally distributed, red 1/f environments. AR(1) methods also underestimate extinction risks in traditionally generated red environments. This work synthesises previous results and provides further insight into the processes driving extinction risk in model populations. We must let

  1. Distribution of oceanic and continental leads in the Arabian-Nubian Shield

    USGS Publications Warehouse

    Stacey, J.S.; Stoeser, D.B.

    1983-01-01

    New common lead data for feldspar, whole-rock, and galena samples from the Arabian-Nubian Shield, together with data from previous work, can be divided into two main groups. Group I leads have oceanic (mantle) characteristics, whereas group II leads have incorporated a continental-crustal component of at least early Proterozoic age. The group I leads are found in rocks from the Red Sea Hills of Egypt and the western and southern parts of the Arabian Shield. Group II leads are found in rocks from the northeastern and eastern parts of the Arabian Shield, as well as from the southeastern Shield near Najran. They are also found in rocks to the south in Yemen, to the east in Oman, and to the west at Aswan, Egypt. This distribution of data suggests that the Arabian-Nubian Shield has an oceanic core flanked by rocks that have developed, at least in part, from older continental material. Two mechanisms are suggested by which this older lead component could have been incorporated into the late Proterozoic rocks, and each may have operated in different parts of the Shield. The older lead component either was derived directly from an underlying early Proterozoic basement or was incorporated from subducted pelagic sediments or sediments derived from an adjacent continent. New U-Pb zircon data indicate the presence of an early Proterozoic basement southeast of Jabal Dahul in the eastern Arabian Shield. These data, together with 2,000-Ma-old zircons from the Al Amar fault zone, verify the implication of the common lead data that at least a part of the eastern Arabian Shield has an older continental basement. Because continental margins are particularly favorable locations for development of ore deposits, these findings may have important economic implications, particularly for tin, tungsten, and molybdenum exploration. ?? 1983 Springer-Verlag.

  2. Climate forcing by anthropogenic aerosols.

    PubMed

    Charlson, R J; Schwartz, S E; Hales, J M; Cess, R D; Coakley, J A; Hansen, J E; Hofmann, D J

    1992-01-24

    Although long considered to be of marginal importance to global climate change, tropospheric aerosol contributes substantially to radiative forcing, and anthropogenic sulfate aerosol in particular has imposed a major perturbation to this forcing. Both the direct scattering of shortwavelength solar radiation and the modification of the shortwave reflective properties of clouds by sulfate aerosol particles increase planetary albedo, thereby exerting a cooling influence on the planet. Current climate forcing due to anthropogenic sulfate is estimated to be -1 to -2 watts per square meter, globally averaged. This perturbation is comparable in magnitude to current anthropogenic greenhouse gas forcing but opposite in sign. Thus, the aerosol forcing has likely offset global greenhouse warming to a substantial degree. However, differences in geographical and seasonal distributions of these forcings preclude any simple compensation. Aerosol effects must be taken into account in evaluating anthropogenic influences on past, current, and projected future climate and in formulating policy regarding controls on emission of greenhouse gases and sulfur dioxide. Resolution of such policy issues requires integrated research on the magnitude and geographical distribution of aerosol climate forcing and on the controlling chemical and physical processes.

  3. Climate Forcing by Anthropogenic Aerosols

    NASA Astrophysics Data System (ADS)

    Charlson, R. J.; Schwartz, S. E.; Hales, J. M.; Cess, R. D.; Coakley, J. A., Jr.; Hansen, J. E.; Hofmann, D. J.

    1992-01-01

    Although long considered to be of marginal importance to global climate change, tropospheric aerosol contributes substantially to radiative forcing, and anthropogenic sulfate aerosol in particular has imposed a major perturbation to this forcing. Both the direct scattering of short-wavelength solar radiation and the modification of the shortwave reflective properties of clouds by sulfate aerosol particles increase planetary albedo, thereby exerting a cooling influence on the planet. Current climate forcing due to anthropogenic sulfate is estimated to be -1 to -2 watts per square meter, globally averaged. This perturbation is comparable in magnitude to current anthropogenic greenhouse gas forcing but opposite in sign. Thus, the aerosol forcing has likely offset global greenhouse warming to a substantial degree. However, differences in geographical and seasonal distributions of these forcings preclude any simple compensation. Aerosol effects must be taken into account in evaluating anthropogenic influences on past, current, and projected future climate and in formulating policy regarding controls on emission of greenhouse gases and sulfur dioxide. Resolution of such policy issues requires integrated research on the magnitude and geographical distribution of aerosol climate forcing and on the controlling chemical and physical processes.

  4. Climate forcing by anthropogenic aerosols

    NASA Technical Reports Server (NTRS)

    Charlson, R. J.; Schwartz, S. E.; Hales, J. M.; Cess, R. D.; Coakley, J. A., Jr.; Hansen, J. E.; Hofmann, D. J.

    1992-01-01

    Although long considered to be of marginal importance to global climate change, tropospheric aerosol contributes substantially to radiative forcing, and anthropogenic sulfate aerosol, in particular, has imposed a major perturbation to this forcing. Both the direct scattering of short-wavelength solar radiation and the modification of the shortwave reflective properties of clouds by sulfate aerosol particles increase planetary albedo, thereby exerting a cooling influence on the planet. Current climate forcing due to anthropogenic sulfate is estimated to be -1 to -2 watts per square meter, globally averaged. This perturbation is comparable in magnitude to current anthropogenic greenhouse gas forcing but opposite in sign. Thus, the aerosol forcing has likely offset global greenhouse warming to a substantial degree. However, differences in geographical and seasonal distributions of these forcings preclude any simple compensation. Aerosol effects must be taken into account in evaluating anthropogenic influences on past, current, and projected future climate and in formulating policy regarding controls on emission of greenhouse gases and sulfur dioxide. Resolution of such policy issues requires integrated research on the magnitude and geographical distribution of aerosol climate forcing and on the controlling chemical and physical processes.

  5. Dispersal leads to spatial autocorrelation in species distributions: A simulation model

    USGS Publications Warehouse

    Bahn, V.; Krohn, W.B.; O'Connor, R.J.

    2008-01-01

    Compared to population growth regulated by local conditions, dispersal has been underappreciated as a central process shaping the spatial distribution of populations. This paper asks: (a) which conditions increase the importance of dispersers relative to local recruits in determining population sizes? and (b) how does dispersal influence the spatial distribution patterns of abundances among connected populations? We approached these questions with a simulation model of populations on a coupled lattice with cells of continuously varying habitat quality expressed as carrying capacities. Each cell contained a population with the basic dynamics of density-regulated growth, and was connected to other populations by immigration and emigration. The degree to which dispersal influenced the distribution of population sizes depended most strongly on the absolute amount of dispersal, and then on the potential population growth rate. Dispersal decaying in intensity with distance left close neighbours more alike in population size than distant populations, leading to an increase in spatial autocorrelation. The spatial distribution of species with low potential growth rates is more dependent on dispersal than that of species with high growth rates; therefore, distribution modelling for species with low growth rates requires particular attention to autocorrelation, and conservation management of these species requires attention to factors curtailing dispersal, such as fragmentation and dispersal barriers. ?? 2007 Elsevier B.V. All rights reserved.

  6. Simulated big sagebrush regeneration supports predicted changes at the trailing and leading edges of distribution shifts

    USGS Publications Warehouse

    Schlaepfer, Daniel R.; Taylor, Kyle A.; Pennington, Victoria E.; Nelson, Kellen N.; Martin, Trace E.; Rottler, Caitlin M.; Lauenroth, William K.; Bradford, John B.

    2015-01-01

    Many semi-arid plant communities in western North America are dominated by big sagebrush. These ecosystems are being reduced in extent and quality due to economic development, invasive species, and climate change. These pervasive modifications have generated concern about the long-term viability of sagebrush habitat and sagebrush-obligate wildlife species (notably greater sage-grouse), highlighting the need for better understanding of the future big sagebrush distribution, particularly at the species' range margins. These leading and trailing edges of potential climate-driven sagebrush distribution shifts are likely to be areas most sensitive to climate change. We used a process-based regeneration model for big sagebrush, which simulates potential germination and seedling survival in response to climatic and edaphic conditions and tested expectations about current and future regeneration responses at trailing and leading edges that were previously identified using traditional species distribution models. Our results confirmed expectations of increased probability of regeneration at the leading edge and decreased probability of regeneration at the trailing edge below current levels. Our simulations indicated that soil water dynamics at the leading edge became more similar to the typical seasonal ecohydrological conditions observed within the current range of big sagebrush ecosystems. At the trailing edge, an increased winter and spring dryness represented a departure from conditions typically supportive of big sagebrush. Our results highlighted that minimum and maximum daily temperatures as well as soil water recharge and summer dry periods are important constraints for big sagebrush regeneration. Overall, our results confirmed previous predictions, i.e., we see consistent changes in areas identified as trailing and leading edges; however, we also identified potential local refugia within the trailing edge, mostly at sites at higher elevation. Decreasing

  7. Distribution of toxic elements and transfer from the environment to humans traced by using lead isotopes. A case of study in the Sarno River basin, south Italy.

    PubMed

    Cicchella, Domenico; Hoogewerff, Jurian; Albanese, Stefano; Adamo, Paola; Lima, Annamaria; Taiani, Manuela V E; De Vivo, Benedetto

    2016-04-01

    The results of a large geochemical study on various environmental media (soil, stream sediment, groundwater, surface water, lettuce and human hair) of the Sarno River basin, which is one of the most polluted areas in Italy, are presented. Further, it aims to deepen our understanding of the distribution of Pb and its isotope composition for the differentiation between natural and anthropogenic metal sources. Our results show the environmental media to be significantly enriched in Cr, Cu, Pb, Hg, Zn, and to a lesser extent in Sb, Cd and Ni compared to the natural local background variation. The numerous industrial activities (mainly tanneries) have caused environmental pollution especially Cr and Hg in soils and sediment samples. Such contamination is also evident in lettuce and in the hair of the resident population, which shows particularly high values for both Cr and Hg. The unusually high As, Be and Sn concentrations arise mostly from natural sources due to the volcanic nature of the investigated area. Lead isotope measurements indicate a trend suggesting mixing between two end-members, one of clear natural origin (geogenic) and another related to human activities (anthropogenic). Lead isotope results demonstrate that Pb in hair of inhabitants is similar to those in the local topsoil and that gasoline is one of the main, but not the only source of metal pollution. The most important exposure risks within the study area are associated with toxic elements levels in topsoil and stream sediment, and the ingestion of locally grown lettuce. The high concentrations of these elements in hair are a further confirmation of this exposure pathway.

  8. Thermodynamic modeling of lead distribution among matte, slag, and liquid copper

    SciTech Connect

    Degterov, S.A.; Pelton, A.D.

    1999-12-01

    Recently, a thermodynamic database was developed for the calculation of equilibria involved in the production of copper. The present study is concerned with the further development of the thermodynamic models and the database of model parameters for the matte, slag, and blister copper phases with a view to including Pb in the database and phase equilibrium data available in the literature are reviewed, critically assessed, and optimized with the modified quasi-chemical model. When used with the Gibbs energy minimization software and other databases of the FACT thermodynamic computing system, the database developed in the present study can be used for the calculation of matte-slag-copper-gas phase equilibria during copper smelting and converting. The distribution of lead among these phases can be computed. For example, the distribution of lead among matte, silica-saturated slag, and copper has been calculated at metal saturation, or under fixed partial pressure of SO{sub 2}, and has been compared with the available experimental data. The Pb distributions among the equilibrium phases have been calculated under various conditions, which are difficult to study experimentally, such as at magnetite saturation or under various oxygen partial pressures and iron to silica ratios in the slag.

  9. A seller-buyer supply chain model with exponential distribution lead time

    NASA Astrophysics Data System (ADS)

    Bahri, Mehrab; Tarokh, Mohammad Jafar

    2012-08-01

    Supply chain is an accepted way of remaining in the competition in today's rapidly changing market. This paper presents a coordinated seller-buyer supply chain model in two stages, which is called Joint Economic Lot Sizing (JELS) in literature. The delivery activities in the supply chain consist of a single raw material. We assume that the delivery lead time is stochastic and follows an exponential distribution. Also, the shortage during the lead time is permitted and completely back-ordered for the buyer. With these assumptions, the annual cost function of JELS is minimized. At the end, a numerical example is presented to show that the integrated approach considerably improves the costs in comparison with the independent decisions by seller and buyer.

  10. The distribution of dissolved lead in the coastal waters of the East China Sea.

    PubMed

    Li, Yan; Yang, Rujun; Zhang, Aibin; Wang, Shirong

    2014-08-30

    The distribution of dissolved lead in the coastal waters of the East China Sea was investigated seasonally. The average concentrations in surface waters during the spring and autumn were 0.52 nM and 0.27 nM, respectively. In the spring, the concentration of dissolved Pb in the surface waters and bottom waters ranged from 0.13 to 1.86 nM and from 0.15 to 0.94 nM, respectively. For both the surface water and the bottom water, the highest values were observed at the Yangtze River Estuary. Seasonal variability of D-Pb between spring and autumn in the ECS was observed. These results suggested that riverine inputs and atmospheric inputs may be the main sources of lead in this area, while adsorption and co-precipitation on suspended particles at the river estuary and biological process may be the major sinks.

  11. Next-to-Leading Order Predictions for W + 3-Jet Distributions at Hadron Colliders

    SciTech Connect

    Berger, C.F.; Bern, Z.; Dixon, L.J.; Febres Cordero, F.; Forde, D.; Gleisberg, T.; Ita, H.; Kosower, D.A.; Maitre, D.; /Durham U.

    2009-12-09

    We present next-to-leading order QCD predictions for a variety of distributions in W + 3-jet production at both the Tevatron and the Large Hadron Collider. We include all subprocesses and incorporate the decay of the W boson into leptons. Our results are in excellent agreement with existing Tevatron data and provide the first quantitatively precise next-to-leading order predictions for the LHC. We include all terms in an expansion in the number of colors, confirming that the specific leading-color approximation used in our previous study is accurate to within three percent. The dependence of the cross section on renormalization and factorization scales is reduced significantly with respect to a leading-order calculation. We study different dynamical scale choices, and find that the total transverse energy is significantly better than choices used in previous phenomenological studies. We compute the one-loop matrix elements using on-shell methods, as numerically implemented in the BlackHat code. The remaining parts of the calculation, including generation of the real-emission contributions and integration over phase space, are handled by the SHERPA package.

  12. High-throughput approaches for evaluating absorption, distribution, metabolism and excretion properties of lead compounds.

    PubMed

    Tarbit, M H; Berman, J

    1998-06-01

    Combinatorial chemistry methods and high-throughput screening for leads in industrial drug discovery have generated a potential bottleneck in the optimisation processes that seek to align potency with good pharmacokinetics in order to produce good medicines. This has resulted in the need for higher throughput methods of screening for absorption, distribution, metabolism and excretion properties. Significant progress has been made in throughput of in vivo pharmacokinetic studies, with the introduction of cassette, or multiple-in-one, protocols. In this technique, typically up to ten compounds are administered in one dose and analysed concomitantly on the mass spectrometer. High-throughput methods in in vitro absorption, distribution, metabolism and excretion are less well-developed as yet, and current approaches comprise automation of well-established methods for absorption using cell lines and metabolism using liver microsomes.

  13. Angular distribution X-ray photoelectron spectroscopy studies on compacted lead ion selective membrane powers

    SciTech Connect

    Young, V.; McCaslin, P.C.

    1985-04-01

    Changes in the distribution of species in the near surface region of compacted lead ion selective membrane powders, as revealed by angular distribution XPS, are reported. Scanning electron micrographs of pellets pressed at pressures ranging from a low of 7 lb/in./sup 2/ to a high of 15,000 lb/in./sup 2/ reveal surfaces of almost undistorted, compacted spheres with an average diameter of 0.25 ..mu..m. For untreated membranes, angular distribution XPS reveals the stratification of the near surface region of the surface layer of spheres. Scanning electron micrographs of EDTA and HClO/sub 4/ treated pellets show that an erosion of the surfaces occurs and angular distribution XPS analysis reveals the stratification of the near surface region of the new surfaces. Profilometry has been used to measure the surface topography of the pellets, and the data have been used to assess the effect of roughness on XPS intensity ratios. 47 references, 8 figures, 4 tables.

  14. [Distribution characteristics of lead in different particle size fractions of surface soil of a lead-acid battery factory contaminated site].

    PubMed

    Yue, Xi; Sun, Ti-chang; Huang, Jin-lou

    2013-09-01

    In this research, six topsoil samples (0-20 cm) were collected in the heavy-metal lead contaminated soil of one lead battery factory in south-west China as research object, which were later divided into seven particle size fractions, and analyzed for the lead concentration as well as the correlation between the lead concentration and the organic matter content. The result showed that five soil samples were contaminated with lead with different pollution levels, and there were two different trends in the changes of lead concentration as of the change of soil particle size. The lead concentration of the three samples from sewage treatment workshop, the workshop A and the workshop B, showed a first declining and then ascending trend with the decreasing particle size. The lead concentration of the soil samples of the packing workshop and the former production workshop A showed a decreasing trend when the particle size decreased. The lead concentration and the organic matter content showed a positive linear correlation (R2 = 0.8232). Soil organic matter has the ability of lead enrichment, and the ability declines with the decreasing particle size. Soil texture may be an important factor for the interaction between soil organic matter and lead distribution.

  15. [Distribution characteristics of lead in different particle size fractions of surface soil of a lead-acid battery factory contaminated site].

    PubMed

    Yue, Xi; Sun, Ti-chang; Huang, Jin-lou

    2013-09-01

    In this research, six topsoil samples (0-20 cm) were collected in the heavy-metal lead contaminated soil of one lead battery factory in south-west China as research object, which were later divided into seven particle size fractions, and analyzed for the lead concentration as well as the correlation between the lead concentration and the organic matter content. The result showed that five soil samples were contaminated with lead with different pollution levels, and there were two different trends in the changes of lead concentration as of the change of soil particle size. The lead concentration of the three samples from sewage treatment workshop, the workshop A and the workshop B, showed a first declining and then ascending trend with the decreasing particle size. The lead concentration of the soil samples of the packing workshop and the former production workshop A showed a decreasing trend when the particle size decreased. The lead concentration and the organic matter content showed a positive linear correlation (R2 = 0.8232). Soil organic matter has the ability of lead enrichment, and the ability declines with the decreasing particle size. Soil texture may be an important factor for the interaction between soil organic matter and lead distribution. PMID:24289023

  16. Distribution patterns of lead in urban soil and dust in Shenyang city, Northeast China.

    PubMed

    Wang, Jinda; Ren, Huimin; Zhang, Xuelin

    2006-01-01

    We investigated the spatial distribution of Pb in soil and dust samples collected from 54 sites in Shenyang city, Liaoning province, Northeast China. Soil background Pb concentration was 22 mg kg(-1) and control values from non-industrial areas were 33 mg kg(-1) for soil and 38 mg kg(-1) for dust. Soil Pb concentrations varied widely, ranging from 26 to 2911 mg kg(-1), with a mean concentration of 200 mg kg(-1), 9 times the background value and 6 times the control value. There was great variation in soil Pb, with a coefficient of variation (CV) of 1.06 and a standard deviation (SD) of 212 mg kg(-1). Dust Pb concentrations fluctuated from 20 to 2810 mg kg(-1), with a mean value of 220 mg kg(-1), almost 6 times the control value. No significant differences in distribution were observed between soil Pb and dust Pb. The highest Pb concentration was observed in Tiexi district in an industrial area. Soil Pb concentration decreased with depth and with distance from the pollution source. Lead concentrations initially changed little but then decreased with distance from the roadside, and were generally higher on the east side of roads than on the west. Lead contents in different categories of urban area differed substantially with dust and soil Pb concentrations decreasing in the sequence: industrial >business >mixed (residential, culture and education)> reference areas.

  17. Mobilization and distribution of lead originating from roof dust and wet deposition in a roof runoff system.

    PubMed

    Yu, Jianghua; Yu, Haixia; Huang, Xiaogu

    2015-12-01

    In this research, the mobilization and distribution of lead originating in roof dust and wet deposition were investigated within a roof dust-rooftop-runoff system. The results indicated that lead from roof dust and wet deposition showed different transport dynamics in runoff system and that this process was significantly influenced by the rainfall intensity. Lead present in the roof dust could be easily washed off into the runoff, and nearly 60 % of the total lead content was present in particulate form. Most of the lead from the roof dust was transported during the late period of rainfall; however, the lead concentration was higher for several minutes at the rainfall beginning. Even though some of the lead from wet deposition, simulated with a standard isotope substance, was adsorbed onto adhered roof dust and/or retained on rooftop in runoff system, most of it (50-82 %) remained as dissolved lead in the runoff for rainfall events of varying intensity. Regarding the distribution of lead in the runoff system, the results indicated that it could be carried in the runoff in dissolved and particulate form, be adsorbed to adhered roof dust, or remain on the rooftop because of adsorption to the roof material. Lead from the different sources showed different distribution patterns that were also related to the rainfall intensity. Higher rainfall intensity resulted in a higher proportion of lead in the runoff and a lower proportion of lead remaining on the rooftop.

  18. Determination of Polarised Parton Distributions in the Nucleon --- Next to Leading Order QCD Analysis

    NASA Astrophysics Data System (ADS)

    Tatur, Stanislaw; Bartelski, Jan; Kurzela, Miroslaw

    2000-03-01

    We have made next to leading order QCD fit to the deep inelastic spin asymmetries on nucleons and we have determined polarised quark and gluon densities. The functional form for such distributions was inspired by the Martin, Roberts and Stirling fit for unpolarised case. In addition to usually used data points (averaged over x and Q2) we have also considered the sample containing points with similar x and different Q2. It seems that splitting of quark densities into valence and sea contribution is strongly model dependent and only their sum (i.e. , Δ u and Δ d) can be precisely determined from the data. Integrated polarised gluon contribution, contrary to some expectations, is relatively small and the sign of it depends on the fact which sample of data points is used.

  19. Chemical oceanography. Increasing anthropogenic nitrogen in the North Pacific Ocean.

    PubMed

    Kim, Il-Nam; Lee, Kitack; Gruber, Nicolas; Karl, David M; Bullister, John L; Yang, Simon; Kim, Tae-Wook

    2014-11-28

    The recent increase in anthropogenic emissions of reactive nitrogen from northeastern Asia and the subsequent enhanced deposition over the extensive regions of the North Pacific Ocean (NPO) have led to a detectable increase in the nitrate (N) concentration of the upper ocean. The rate of increase of excess N relative to phosphate (P) was found to be highest (~0.24 micromoles per kilogram per year) in the vicinity of the Asian source continent, with rates decreasing eastward across the NPO, consistent with the magnitude and distribution of atmospheric nitrogen deposition. This anthropogenically driven increase in the N content of the upper NPO may enhance primary production in this N-limited region, potentially leading to a long-term change of the NPO from being N-limited to P-limited.

  20. Chemical oceanography. Increasing anthropogenic nitrogen in the North Pacific Ocean.

    PubMed

    Kim, Il-Nam; Lee, Kitack; Gruber, Nicolas; Karl, David M; Bullister, John L; Yang, Simon; Kim, Tae-Wook

    2014-11-28

    The recent increase in anthropogenic emissions of reactive nitrogen from northeastern Asia and the subsequent enhanced deposition over the extensive regions of the North Pacific Ocean (NPO) have led to a detectable increase in the nitrate (N) concentration of the upper ocean. The rate of increase of excess N relative to phosphate (P) was found to be highest (~0.24 micromoles per kilogram per year) in the vicinity of the Asian source continent, with rates decreasing eastward across the NPO, consistent with the magnitude and distribution of atmospheric nitrogen deposition. This anthropogenically driven increase in the N content of the upper NPO may enhance primary production in this N-limited region, potentially leading to a long-term change of the NPO from being N-limited to P-limited. PMID:25430767

  1. Increasing anthropogenic nitrogen in the North Pacific Ocean

    NASA Astrophysics Data System (ADS)

    Kim, Il-Nam; Lee, Kitack; Gruber, Nicolas; Karl, David M.; Bullister, John L.; Yang, Simon; Kim, Tae-Wook

    2014-11-01

    The recent increase in anthropogenic emissions of reactive nitrogen from northeastern Asia and the subsequent enhanced deposition over the extensive regions of the North Pacific Ocean (NPO) have led to a detectable increase in the nitrate (N) concentration of the upper ocean. The rate of increase of excess N relative to phosphate (P) was found to be highest (∼0.24 micromoles per kilogram per year) in the vicinity of the Asian source continent, with rates decreasing eastward across the NPO, consistent with the magnitude and distribution of atmospheric nitrogen deposition. This anthropogenically driven increase in the N content of the upper NPO may enhance primary production in this N-limited region, potentially leading to a long-term change of the NPO from being N-limited to P-limited.

  2. Revisiting the pion leading-twist distribution amplitude within the QCD background field theory

    NASA Astrophysics Data System (ADS)

    Zhong, Tao; Wu, Xing-Gang; Wang, Zhi-Gang; Huang, Tao; Fu, Hai-Bing; Han, Hua-Yong

    2014-07-01

    We study the pion leading-twist distribution amplitude (DA) within the framework of Shifman-Vainshtein-Zakharov sum rules under the background field theory. To improve the accuracy of the sum rules, we expand both the quark propagator and the vertex (z.D↔)n of the correlator up to dimension-six operators in the background field theory. The sum rules for the pion DA moments are obtained, in which all condensates up to dimension-six have been taken into consideration. Using the sum rules, we obtain ⟨ξ2⟩|1 GeV=0.338±0.032, ⟨ξ4⟩|1GeV=0.211±0.030 and ⟨ξ6⟩|1GeV=0.163±0.030. It is shown that the dimension-six condensates shall provide sizable contributions to the pion DA moments. We show that the first Gegenbauer moment of the pion leading-twist DA is a2π|1 GeV=0.403±0.093, which is consistent with those obtained in the literature within errors but prefers a larger central value as indicated by lattice QCD predictions.

  3. ρ -meson longitudinal leading-twist distribution amplitude within QCD background field theory

    NASA Astrophysics Data System (ADS)

    Fu, Hai-Bing; Wu, Xing-Gang; Cheng, Wei; Zhong, Tao

    2016-10-01

    We revisit the ρ -meson longitudinal leading-twist distribution amplitude (DA) ϕ2;ρ ∥ by using the QCD sum rules approach within the background field theory. To improve the accuracy of the sum rules for its moments ⟨ξn;ρ ∥⟩ , we include the next-to-leading order QCD correction to the perturbative part and keep all nonperturbative condensates up to dimension-six consistently within the background field theory. The first two moments read ⟨ξ2;ρ ∥⟩|1 GeV=0.241 (28 ) and ⟨ξ4;ρ ∥⟩|1 GeV=0.109 (10 ) , indicating a double humped behavior for ϕ2;ρ ∥ at small energy scale. As an application, we apply them to the B →ρ transition form factors within the QCD light-cone sum rules, which are key components for the decay width Γ (B →ρ ℓνℓ) . To compare with the world average of Γ (B →ρ ℓνℓ) issued by Particle Data Group, we predict |Vub|=3.1 9-0.62+0.65 , which agrees with the BABAR and Omnès parametrization prediction within errors.

  4. Uptake and storage of anthropogenic CO2 in the pacific ocean estimated using two modeling approaches

    NASA Astrophysics Data System (ADS)

    Li, Yangchun; Xu, Yongfu

    2012-07-01

    A basin-wide ocean general circulation model (OGCM) of the Pacific Ocean is employed to estimate the uptake and storage of anthropogenic CO2 using two different simulation approaches. The simulation (named BIO) makes use of a carbon model with biological processes and full thermodynamic equations to calculate surface water partial pressure of CO2, whereas the other simulation (named PTB) makes use of a perturbation approach to calculate surface water partial pressure of anthropogenic CO2. The results from the two simulations agree well with the estimates based on observation data in most important aspects of the vertical distribution as well as the total inventory of anthropogenic carbon. The storage of anthropogenic carbon from BIO is closer to the observation-based estimate than that from PTB. The Revelle factor in 1994 obtained in BIO is generally larger than that obtained in PTB in the whole Pacific, except for the subtropical South Pacific. This, to large extent, leads to the difference in the surface anthropogenic CO2 concentration between the two runs. The relative difference in the annual uptake between the two runs is almost constant during the integration processes after 1850. This is probably not caused by dissolved inorganic carbon (DIC), but rather by a factor independent of time. In both runs, the rate of change in anthropogenic CO2 fluxes with time is consistent with the rate of change in the growth rate of atmospheric partial pressure of CO2.

  5. Speciation and distribution of cadmium and lead in salinized horizons of antrosols

    NASA Astrophysics Data System (ADS)

    Bulgariu, D.; Bulgariu, L.; Astefanei, D.

    2009-04-01

    The utilization of intensive technologies for the vegetable cultivation in glass houses by the administration of high doses of organic fertilizes, the supra-dimensional irrigation and the maintaining of soil at high humidity state, in special in case of vicious drainage have as result the rapid degradation of morphological, chemical and physical characteristics of soils, concretized by: (i) decrease of structural aggregates stability; (ii) more dense packing of soil; (iii) accumulation of easy soluble salts (in special at superior horizons level); (iv) limitation of organic compounds and micro-elements biodisponibility. All these determined a significant reduction of productivity and of exploitation duration of soils from glass houses. These phenomena modified continuously the dynamic of speciation processes and inter-phases distribution, of heavy metals in soils from glass houses, and can determined a non-controlled accumulation of heavy metals, in special as mobile forms with high biodisponibility. Ours studied have been performed using soil profiles drawing from Copou-glass house, Iasi (Romania). Has been followed the modification of distribution for speciation forms of cadmium and lead (two heavy metals with high toxicity degree), between hortic antrosol horizons, and between chemical-mineralogical components of this, with the progressive salinization of superior horizons, in 2007-2008 period. The separation, differentiation and determination of cadmium and lead speciation forms was done by combined solid-liquid sequential extraction (SPE) and extraction in aqueous polymer-inorganic salt two-phase systems (ABS) procedure, presented in some of ours previous studies. After extraction, the total contents of the two heavy metals and fractions from these differential bonded by mineral and organic components of hortic antrosol have been determined by atomic absorption spectrometry. The specific interaction mechanisms of Cd and Pb with organic-mineral components of

  6. Order-disorder transition in conflicting dynamics leading to rank-frequency generalized beta distributions

    NASA Astrophysics Data System (ADS)

    Alvarez-Martinez, R.; Martinez-Mekler, G.; Cocho, G.

    2011-01-01

    The behavior of rank-ordered distributions of phenomena present in a variety of fields such as biology, sociology, linguistics, finance and geophysics has been a matter of intense research. Often power laws have been encountered; however, their validity tends to hold mainly for an intermediate range of rank values. In a recent publication (Martínez-Mekler et al., 2009 [7]), a generalization of the functional form of the beta distribution has been shown to give excellent fits for many systems of very diverse nature, valid for the whole range of rank values, regardless of whether or not a power law behavior has been previously suggested. Here we give some insight on the significance of the two free parameters which appear as exponents in the functional form, by looking into discrete probabilistic branching processes with conflicting dynamics. We analyze a variety of realizations of these so-called expansion-modification models first introduced by Wentian Li (1989) [10]. We focus our attention on an order-disorder transition we encounter as we vary the modification probability p. We characterize this transition by means of the fitting parameters. Our numerical studies show that one of the fitting exponents is related to the presence of long-range correlations exhibited by power spectrum scale invariance, while the other registers the effect of disordering elements leading to a breakdown of these properties. In the absence of long-range correlations, this parameter is sensitive to the occurrence of unlikely events. We also introduce an approximate calculation scheme that relates this dynamics to multinomial multiplicative processes. A better understanding through these models of the meaning of the generalized beta-fitting exponents may contribute to their potential for identifying and characterizing universality classes.

  7. Quantitative assessment of atmospheric emissions of toxic heavy metals from anthropogenic sources in China: historical trend, spatial variation distribution, uncertainties and control policies

    NASA Astrophysics Data System (ADS)

    Tian, H. Z.; Zhu, C. Y.; Gao, J. J.; Cheng, K.; Hao, J. M.; Wang, K.; Hua, S. B.; Wang, Y.; Zhou, J. R.

    2015-04-01

    Anthropogenic atmospheric emissions of typical toxic heavy metals have received worldwide concerns due to their adverse effects on human health and the ecosystem. By determining the best available representation of time-varying emission factors with S-shape curves, we established the multiyear comprehensive atmospheric emission inventories of 12 typical toxic heavy metals (Hg, As, Se, Pb, Cd, Cr, Ni, Sb, Mn, Co, Cu and Zn) from primary anthropogenic activities in China for the period of 1949-2012 for the first time. Further, we allocated the annual emissions of these heavy metals in 2010 at a high spatial resolution of 0.5° × 0.5° grid with ArcGIS methodology and surrogate indexes, such as regional population and gross domestic product (GDP). Our results show that the historical emissions of Hg, As, Se, Cd, Cr, Ni, Sb, Mn, Co, Cu and Zn during the period of 1949-2012, have been increased by about 22-128 times at an annual average growth rate of 5.1-8.0%, amounting to about 79 570 t in 2012. Nonferrous metal smelting, coal combustion of industrial boilers, brake and tyre wear, and ferrous metals smelting represent the dominant sources for Hg / Cd, As / Se / Pb / Cr / Ni / Mn / Co, Sb / Cu, and Zn, respectively. In terms of spatial variation, the majority of emissions were concentrated in relatively developed regions, especially for the northern, eastern and southern coastal regions. In addition, because of the flourishing nonferrous metals smelting industry, several southwestern and central-southern provinces play a prominent role in some specific toxic heavy metals emissions, like Hg in Guizhou and As in Yunnan. Finally, integrated countermeasures are proposed to minimize the final toxic heavy metals discharge on accounting of the current and future demand of energy-saving and pollution reduction in China.

  8. Quantitative assessment of atmospheric emissions of toxic heavy metals from anthropogenic sources in China: historical trend, spatial distribution, uncertainties, and control policies

    NASA Astrophysics Data System (ADS)

    Tian, H. Z.; Zhu, C. Y.; Gao, J. J.; Cheng, K.; Hao, J. M.; Wang, K.; Hua, S. B.; Wang, Y.; Zhou, J. R.

    2015-09-01

    Anthropogenic atmospheric emissions of typical toxic heavy metals have caused worldwide concern due to their adverse effects on human health and the ecosystem. By determining the best available representation of time-varying emission factors with S-shape curves, we establish the multiyear comprehensive atmospheric emission inventories of 12 typical toxic heavy metals (Hg, As, Se, Pb, Cd, Cr, Ni, Sb, Mn, Co, Cu, and Zn) from primary anthropogenic activities in China for the period of 1949-2012 for the first time. Further, we allocate the annual emissions of these heavy metals in 2010 at a high spatial resolution of 0.5° × 0.5° grid with ArcGIS methodology and surrogate indexes, such as regional population and gross domestic product (GDP). Our results show that the historical emissions of Hg, As, Se, Cd, Cr, Ni, Sb, Mn, Co, Cu, and Zn, during the period of 1949-2012, increased by about 22-128 times at an annual average growth rate of 5.1-8.0 %, reaching about 526.9-22 319.6 t in 2012. Nonferrous metal smelting, coal combustion of industrial boilers, brake and tyre wear, and ferrous metal smelting represent the dominant sources of heavy metal emissions. In terms of spatial variation, the majority of emissions are concentrated in relatively developed regions, especially for the northern, eastern, and southern coastal regions. In addition, because of the flourishing nonferrous metal smelting industry, several southwestern and central-southern provinces play a prominent role in some specific toxic heavy metals emissions, like Hg in Guizhou and As in Yunnan. Finally, integrated countermeasures are proposed to minimize the final toxic heavy metals discharge on account of the current and future demand of energy-saving and pollution reduction in China.

  9. Transport, ultrastructural localization, and distribution of chemical forms of lead in radish (Raphanus sativus L.)

    PubMed Central

    Wang, Yan; Shen, Hong; Xu, Liang; Zhu, Xianwen; Li, Chao; Zhang, Wei; Xie, Yang; Gong, Yiqin; Liu, Liwang

    2015-01-01

    Lead (Pb), a ubiquitous but highly toxic heavy metal (HM), is harmful to human health through various pathways including by ingestion of contaminated vegetables. Radish is a worldwide root vegetable crop with significant health and nutritional benefits. However, little is known about Pb translocation and distribution within radish plants after its uptake by the roots. In this study, Pb stress was induced using Pb(NO3)2 in hydroponic culture, aiming to characterize the transport, ultrastructural localization, and distribution of chemical forms of Pb in different tissues of radish. The results showed that the majority of Pb (85.76–98.72%) was retained in underground organs including lateral roots, root heads and taproot skins, while a small proportion of Pb was absorbed by root flesh (0.44–1.56%) or transported to the shoot (1.28–14.24%). A large proportion of Pb (74.11–99.30%) was integrated with undissolved Pb oxalate, protein and pectates forming Pb–phosphate complexes. Moreover, a low-Pb-accumulating line of radish showed a higher proportion of Pb in water-soluble form compared with a high-Pb-accumulating line. Subcellular distribution analysis showed that a large proportion of Pb was bound to cell wall fraction in lateral roots (71.08–80.40%) and taproot skin (46.22–77.94%), while the leaves and roots had 28.36–39.37% and 27.35–46.51% of Pb stored in the soluble fraction, respectively. Furthermore, transmission electron microscopy (TEM) revealed Pb precipitates in intercellular space, cell wall, plasma lemma and vacuoles. Fractionation results also showed the accumulation of Pb on the cell wall, intercellular space and vacuole, and low uptake of undissolved Pb oxalate, protein, pectates and Pb–phosphate complexes, which might be due to low transport efficiency and Pb tolerance of radish. These findings would provide insight into molecular mechanism of Pb uptake and translocation in radish and facilitate development of low-Pb-content cultivars

  10. Transport, ultrastructural localization, and distribution of chemical forms of lead in radish (Raphanus sativus L.).

    PubMed

    Wang, Yan; Shen, Hong; Xu, Liang; Zhu, Xianwen; Li, Chao; Zhang, Wei; Xie, Yang; Gong, Yiqin; Liu, Liwang

    2015-01-01

    Lead (Pb), a ubiquitous but highly toxic heavy metal (HM), is harmful to human health through various pathways including by ingestion of contaminated vegetables. Radish is a worldwide root vegetable crop with significant health and nutritional benefits. However, little is known about Pb translocation and distribution within radish plants after its uptake by the roots. In this study, Pb stress was induced using Pb(NO3)2 in hydroponic culture, aiming to characterize the transport, ultrastructural localization, and distribution of chemical forms of Pb in different tissues of radish. The results showed that the majority of Pb (85.76-98.72%) was retained in underground organs including lateral roots, root heads and taproot skins, while a small proportion of Pb was absorbed by root flesh (0.44-1.56%) or transported to the shoot (1.28-14.24%). A large proportion of Pb (74.11-99.30%) was integrated with undissolved Pb oxalate, protein and pectates forming Pb-phosphate complexes. Moreover, a low-Pb-accumulating line of radish showed a higher proportion of Pb in water-soluble form compared with a high-Pb-accumulating line. Subcellular distribution analysis showed that a large proportion of Pb was bound to cell wall fraction in lateral roots (71.08-80.40%) and taproot skin (46.22-77.94%), while the leaves and roots had 28.36-39.37% and 27.35-46.51% of Pb stored in the soluble fraction, respectively. Furthermore, transmission electron microscopy (TEM) revealed Pb precipitates in intercellular space, cell wall, plasma lemma and vacuoles. Fractionation results also showed the accumulation of Pb on the cell wall, intercellular space and vacuole, and low uptake of undissolved Pb oxalate, protein, pectates and Pb-phosphate complexes, which might be due to low transport efficiency and Pb tolerance of radish. These findings would provide insight into molecular mechanism of Pb uptake and translocation in radish and facilitate development of low-Pb-content cultivars in root vegetable

  11. Distribution and surface enrichment of radionuclides in lead-bismuth eutectic from spallation targets

    NASA Astrophysics Data System (ADS)

    Hammer-Rotzler, Bernadette; Neuhausen, Jörg; Boutellier, Viktor; Wohlmuther, Michael; Zanini, L.; David, J.-C.; Türler, Andreas; Schumann, Dorothea

    2016-07-01

    With the development of new high-power neutron spallation sources --both for scientific application and as neutron production tool for accelerator-driven systems-- the demand for experimentally obtained nuclear data on the residue nuclei production in the target is constantly increasing. In the present work, we examined two lead-bismuth-eutectic targets, irradiated with high-energy protons, concerning their radionuclide content and the spatial distribution of selected isotopes. The first one was the so-called ISOLDE target, being irradiated with 1-1.4GeV protons at CERN-ISOLDE, the second one was the MEGAPIE target, irradiated at PSI with 590MeV protons. In particular, we investigated the phenomenon of radionuclide enrichment on free surfaces in both targets. It turned out that considerable accumulation can be found especially in the case of lanthanides. The depletion process is enhanced at increased temperatures. The results are compared with theoretical predictions; some possible consequences of the findings are illustrated.

  12. Spatial distribution of the trace elements zinc, strontium and lead in human bone tissue.

    PubMed

    Pemmer, B; Roschger, A; Wastl, A; Hofstaetter, J G; Wobrauschek, P; Simon, R; Thaler, H W; Roschger, P; Klaushofer, K; Streli, C

    2013-11-01

    Trace elements are chemical elements in minute quantities, which are known to accumulate in the bone. Cortical and trabecular bones consist of bone structural units (BSUs) such as osteons and bone packets of different mineral content and are separated by cement lines. Previous studies investigating trace elements in bone lacked resolution and therefore very little is known about the local concentration of zinc (Zn), strontium (Sr) and lead (Pb) in BSUs of human bone. We used synchrotron radiation induced micro X-ray fluorescence analysis (SR μ-XRF) in combination with quantitative backscattered electron imaging (qBEI) to determine the distribution and accumulation of Zn, Sr, and Pb in human bone tissue. Fourteen human bone samples (10 femoral necks and 4 femoral heads) from individuals with osteoporotic femoral neck fractures as well as from healthy individuals were analyzed. Fluorescence intensity maps were matched with BE images and correlated with calcium (Ca) content. We found that Zn and Pb had significantly increased levels in the cement lines of all samples compared to the surrounding mineralized bone matrix. Pb and Sr levels were found to be correlated with the degree of mineralization. Interestingly, Zn intensities had no correlation with Ca levels. We have shown for the first time that there is a differential accumulation of the trace elements Zn, Pb and Sr in BSUs of human bone indicating different mechanisms of accumulation. PMID:23932972

  13. Distributions of selenium, iodine, lead, thorium and uranium in Japanese river waters

    SciTech Connect

    Tagami, K.; Uchida, S.

    2007-07-01

    Long-lived radionuclides released from nuclear facilities, such as deep underground disposal facilities, could reach humans through several transfer paths in the environment. Uses of ground water and river water for agricultural field irrigation and for drinking water are important paths. In order to understand behavior of long-lived radionuclides in the terrestrial water environment, we carried out a natural analogue study, that is, measurement of selenium (Se), iodine (I), lead (Pb), thorium (Th) and uranium (U) concentrations in 45 Japanese rivers at 10 sampling points from the upper stream to the river mouth for each river. Geometric mean concentrations for Se, I, Pb, Th and U were 0.057, 1.4, 0.039, 0.0055, 0.0109 ng/mL, respectively. Distribution patterns from upper stream to river mouth were different by elements, for instance, the concentrations of I, Th and U increased when the sampling points were nearer the river mouth, while that of Se were almost constant. For Pb, the highest value was observed in the middle part of each river in many cases. (authors)

  14. Derivation of soil thresholds for lead applying species sensitivity distribution: A case study for root vegetables.

    PubMed

    Ding, Changfeng; Ma, Yibing; Li, Xiaogang; Zhang, Taolin; Wang, Xingxiang

    2016-02-13

    The combination of food quality standard and soil-plant transfer models can be used to derive critical limits of heavy metals for agricultural soils. In this paper, a robust methodology is presented, taking the variations of plant species and cultivars and soil properties into account to derive soil thresholds for lead (Pb) applying species sensitivity distribution (SSD). Three species of root vegetables (four cultivars each for radish, carrot, and potato) were selected to investigate their sensitivity differences for accumulating Pb through greenhouse experiment. Empirical soil-plant transfer model was developed from carrot New Kuroda grown in twenty-one soils covering a wide variation in physicochemical properties and was used to normalize the bioaccumulation data of non-model cultivars. The relationship was then validated to be reliable and would not cause over-protection using data from field experimental sites and published independent studies. The added hazardous concentration for protecting 95% of the cultivars not exceeding the food quality standard (HC5add) were then calculated from the Burr Type III function fitted SSD curves. The derived soil Pb thresholds based on the added risk approach (total soil concentration subtracting the natural background part) were presented as continuous or scenario criteria depending on the combination of soil pH and CEC. PMID:26513560

  15. Forced distribution rating systems: when does "rank and yank" lead to adverse impact?

    PubMed

    Giumetti, Gary W; Schroeder, Amber N; Switzer, Fred S

    2015-01-01

    Despite widespread use of forced distribution rating systems (FDRSs), the potential for this performance appraisal method to lead to adverse impact (AI) in a layoff context has yet to be examined empirically. Thus, the current study uses a Monte Carlo simulation to examine the likelihood of encountering AI violations when an FDRS is used in the context of layoffs. The primary research questions included an examination of how AI violations change depending on the definition of the employment action (i.e., retention vs. layoff), the length of the repeated layoffs, and whether or not laid off employees are replaced each year. The current study also examined the impact of the size of the organization, the percentage of the workforce laid off, and the type of AI calculation method used on the likelihood of AI violations. Results suggest that defining the employment action as layoffs (rather than as retentions) may result in a greater likelihood of AI violations, and AI violations are likely to peak in the 1st year of use. Further, replacing laid off employees may result in higher levels of AI over time as compared with not replacing layoffs. Additionally, the greatest risk for AI occurs when the organization size is large (i.e., N = 10,000) and when certain AI calculation methods are used. Results are discussed in terms of their practical and legal implications for organizations.

  16. Spatial distribution, health risk assessment, and isotopic composition of lead contamination of street dusts in different functional areas of Beijing, China.

    PubMed

    Han, Lanfang; Gao, Bo; Wei, Xin; Xu, Dongyu; Gao, Li

    2016-02-01

    Street dusts from heavy density traffic area (HDTA), tourism area (TA), residential area (RA), and educational area (EA) in Beijing were collected to explore the distribution, health risk assessment, and source of lead (Pb). The average concentration of Pb in TA was the highest among the four areas. Compared with other cities, Pb concentrations in Beijing were generally at moderate or low levels. The average value (14.05) of ecological risk index (RI) indicated that Pb was at "low pollution risk" status. According to the calculation on hazard index (HI), the ingestion of dust particles of children and adults was the major route of exposure to street dusts in four studied areas, followed by dermal contact. The lower values of HI than 1 further suggested that non-carcinogenic risks of Pb in the street dusts were in the low range. Comparing (206)Pb/(207)Pb and (208)Pb/(207)Pb ratios of street dusts with other environmental samples, it was found that atmospheric deposition of coal combustion dust might be the main pathway for anthropogenic Pb input to the street dusts in four functional areas. PMID:26490894

  17. Spatial distribution, health risk assessment, and isotopic composition of lead contamination of street dusts in different functional areas of Beijing, China.

    PubMed

    Han, Lanfang; Gao, Bo; Wei, Xin; Xu, Dongyu; Gao, Li

    2016-02-01

    Street dusts from heavy density traffic area (HDTA), tourism area (TA), residential area (RA), and educational area (EA) in Beijing were collected to explore the distribution, health risk assessment, and source of lead (Pb). The average concentration of Pb in TA was the highest among the four areas. Compared with other cities, Pb concentrations in Beijing were generally at moderate or low levels. The average value (14.05) of ecological risk index (RI) indicated that Pb was at "low pollution risk" status. According to the calculation on hazard index (HI), the ingestion of dust particles of children and adults was the major route of exposure to street dusts in four studied areas, followed by dermal contact. The lower values of HI than 1 further suggested that non-carcinogenic risks of Pb in the street dusts were in the low range. Comparing (206)Pb/(207)Pb and (208)Pb/(207)Pb ratios of street dusts with other environmental samples, it was found that atmospheric deposition of coal combustion dust might be the main pathway for anthropogenic Pb input to the street dusts in four functional areas.

  18. Anthropogenic impacts on the biogeochemistry and cycling of antimony.

    PubMed

    Shotyk, William; Krachler, Michael; Chen, Bin

    2005-01-01

    Antimony is a potentially toxic trace element with no known biological function. Antimony is commonly enriched in coals, and fossil fuel combustion appears to be the largest single source of anthropogenic Sb to the global atmosphere. Abundant in sulfide minerals, its emission to the atmosphere from anthropogenic activities is linked to the mining and metallurgy of non-ferrous metals, especially Pb, Cu, and Zn. In particular, the geochemical and mineralogical association of Sb with Pb minerals implies that, like Pb, Sb has been emitted to the environment for thousands of years because of Pb mining, smelting, and refining. In the US alone, there are more than 400 former secondary lead smelting operations and worldwide there are 133 Pb-Zn smelters in operation today. Antimony is used in creating and improving dozens of industrial and commercial materials including various alloys, ceramics, glasses, plastics, and synthetic fabrics, making waste incineration another important source of Sb to the environment. Enrichments of Sb in atmospheric aerosols, plants, soils, sediments, as well as alpine and polar snow and ice suggest that Sb contamination is extensive, but there are very few quantitative studies of the geographic extent, intensity, and chronology of this contamination. There is an urgent need to quantify the extent of human impacts and how these have changed with time. The decreasing inventories of anthropogenic Sb with time in peat cores from Switzerland and Scotland suggest that the atmospheric Sb flux may be declining, but there have been too few studies to make any general conclusions. In fact, some studies of sediments and biomonitors in central Europe show little decline in Sb concentrations during the past decades. There is an obvious need for reliable data from well dated archives such as polar snow and ice, peat bogs, and sediments. The air concentrations, extent of enrichment, particle size distribution, and rate of deposition of Sb in urban areas is

  19. Comparative effects of ten dithiocarbamate and thiuram compounds on tissue distribution and excretion of lead in rats

    SciTech Connect

    Oskarsson, A.

    1987-10-01

    The dithiocarbamate and thiuram compounds, including disulfiram, were compared for their efficacies in influencing tissue distribution of a trace dose of intravenously injected lead plus /sup 203/Pb in rats. The tested compounds were sodium diethyldithiocarbamate (DEDTC), sodium dimethyldithiocarbamate (DMDTC), tetraethylthiuram disulfide (disulfiram), a complex of zinc and manganese ethylenebisdithiocarbamate (mancozeb), manganese ethylenebisdithiocarbamate (maneb), sodium monomethyldithiocarbamate (metham), zinc propylene bisdithiocarbamate (propineb), tetramethylthiuram disulfide (thiram), zinc ethylenebisdithiocarbamate (zineb), and zinc dimethyldithiocarbamate (ziram). The results of this study show that interactions can occur between lead and DEDTC, DMDTC, disulfiram, metham, thiram, and ziram, resulting in increased levels of lead in brain and probably potentiation of the neurotoxic effects of lead.

  20. A survey of spatially distributed exterior dust lead loadings in New York City.

    PubMed

    Caravanos, Jack; Weiss, Arlene L; Blaise, Marc J; Jaeger, Rudolph J

    2006-02-01

    This work documents ambient lead dust deposition values (lead loading) for the boroughs of New York City in 2003-2004. Currently, no regulatory standards exist for exterior concentrations of lead in settled dust. This is in contrast to the clearance and risk assessment standards that exist for interior residential dust. The reported potential for neurobehavioral toxicity and adverse cognitive development in children due to lead exposure prompts public health concerns about undocumented lead sources. Such sources may include settled dust of outdoor origin. Dust sampling throughout the five boroughs of NYC was done from the top horizontal portion of pedestrian traffic control signals (PTCS) at selected street intersections along main thoroughfares. The data (n=214 samples) show that lead in dust varies within each borough with Brooklyn having the highest median concentration (730 microg/ft2), followed in descending order by Staten Island (452 microg/ft2), the Bronx (382 microg/ft2), Queens (198 microg/ft2) and finally, Manhattan (175 microg/ft2). When compared to the HUD/EPA indoor lead in dust standard of 40 microg/ft2, our data show that this value is exceeded in 86% of the samples taken. An effort was made to determine the source of the lead in the dust atop of the PTCS. The lead in the dust and the yellow signage paint (which contains lead) were compared using isotopic ratio analysis. Results showed that the lead-based paint chip samples from intact signage did not isotopically match the dust wipe samples taken from the same surface. We know that exterior dust containing lead contributes to interior dust lead loading. Therefore, settled leaded dust in the outdoor environment poses a risk for lead exposure to children living in urban areas, namely, areas with elevated childhood blood lead levels and background lead dust levels from a variety of unidentified sources.

  1. Estimation of global anthropogenic dust aerosol using CALIOP satellite

    NASA Astrophysics Data System (ADS)

    Chen, B.; Huang, J.; Liu, J.

    2014-12-01

    Anthropogenic dust aerosols are those produced by human activity, which mainly come from cropland, pasture, and urban in this paper. Because understanding of the emissions of anthropogenic dust is still very limited, a new technique for separating anthropogenic dust from natural dustusing CALIPSO dust and planetary boundary layer height retrievalsalong with a land use dataset is introduced. Using this technique, the global distribution of dust is analyzed and the relative contribution of anthropogenic and natural dust sources to regional and global emissions are estimated. Local anthropogenic dust aerosol due to human activity, such as agriculture, industrial activity, transportation, and overgrazing, accounts for about 22.3% of the global continentaldust load. Of these anthropogenic dust aerosols, more than 52.5% come from semi-arid and semi-wet regions. On the whole, anthropogenic dust emissions from East China and India are higher than other regions.

  2. Diagnosis of spatial distribution and severity of mid-latitude storms in an ensemble of European AOGCMs under anthropogenic climate change

    NASA Astrophysics Data System (ADS)

    Leckebusch, G. C.; Donat, M.; Renggli, D.; Ulbrich, U.; Pinto, J. G.

    2009-09-01

    Large structural damages and financial losses are caused by severe extra tropical cyclone systems of the mid-latitudes. Although in the decades from 1960 to the mid-90s a significant increase in the number of severe storms in the North-Atlantic / European region is undouptful, no clear attribution to anthropogenic climate change could be depicted. Nevertheless, the importance of such meteorological high impact phenomenon, underlines the necessity to estimate potential future developments and occurrence of storms over the Northeast Atlantic and Europe. This study investigates the occurrence of mid-latitude cyclones and wind storms under anthropogenic climate change (ACC, IPCC SRES A1B) conditions from a multi-model perspective and aims at a robust diagnostic of the future occurrence of extreme cyclones under ACC based on an ensemble of state-of-the-art global atmosphere-ocean circulation models and at deducing measures of uncertainties of these ACC signals. Two different investigation techniques are applied. Firstly, an objective cyclone identification and tracking method based on mean sea level pressure, and secondly, an impact based severity measure incorporating the daily maximum wind speed. Thus, a measure more related to the dynamic development features, as well as a proxy for the severity of impacts is used to ensure the relevance of the deduced results for the larger stakeholder community as e.g. reinsurance companies. The model results are validated with ECMWF-reanalysis data (ERA40). In an ensemble mean perspective the overall number of cyclone systems in the A1B scenario is decreased, physically consistent with a reduced low-tropospheric mean baroclinicity due to a larger zonal mean temperature increase in polar regions than in mid- to low-latitudes. For extreme cyclones, however, two hotspots of increased activity are revealed by the ensemble mean: one over the Northeast-Pacific, and another over the Northeast-Atlantic. Allthough model

  3. Morphological Analysis and Solubility of Lead Particles: Effect of Phosphates and Implications to Drinking Water Distribution

    EPA Science Inventory

    Objective • Describe lead synthesis experiments conduced to model the impact of water quality on lead particles and solubility • Develop a model system that can be used for lead solubility studies • Understand the how phosphates impact the morphology and solubility transfo...

  4. [Effect of silicon on translocation and morphology distribution of lead in soil-tobacco system].

    PubMed

    Yan, Yi-Hua; Zheng, Zi-Cheng; Li, Ting-Xuan; Zhang, Xi-Zhou; Wang, Yong

    2014-10-01

    Taking tobacco as test material, a pot experiment was conducted to study the effect of silicon on translocation of lead (Pb) form soil to tobacco in order to explore effective measures for reducing Pb concentration in tobacco leaf. The results showed that silicon application promoted the transformation of exchangeable Pb into Fe-Mn oxide-bound Pb in non-rhizospheric soil, and into Fe-Mn oxide-bound Pb and residual Pb in rhizospheric soil, which decreased the availability and mobility of Pb in the soil. Silicon application significantly reduced the Pb uptake of tobacco, with the content of Pb being decreased by 6.5% to 44.0% in tobacco, and 3.1% to 60.4% in leaf. Silicon application promoted the transformation of ethanol-extractable, H2O-extractable Pb and NaCl-extractable Pb into HCl-extractable Pb and residual Pb in root, stem and leaf of tobacco, which reduced the toxicity and mobility of Pb in tobacco. Silicon restricted the transportation of Pb from soil to tobacco leaf by reducing the mobility index of Pb from soil to root and the mobility index of Pb from root to stem in soil-tobacco system. Meanwhile, the mobility index of Pb from stem to leaf in soil-tobacco system showed a rising-and-falling trend with the increase of Pb application. Silicon inhibited the Pb migration from soil to tobacco leaf by reducing availability of Pb, mitigating toxicity of Pb to tobacco, and changing the distribution of Pb forms in tobacco, consequently reducing Pb concentration of tobacco leaf. These results demonstrated silicon application could be effective in reducing translocation of Pb from soil to tobacco.

  5. Source and distribution of lead in the surface sediments from the South China Sea as derived from Pb isotopes.

    PubMed

    Zhu, Laimin; Guo, Laodong; Gao, Ziyou; Yin, Guan; Lee, Ben; Wang, Fei; Xu, Jiang

    2010-11-01

    Rapid economic development in East Asian countries has inevitably resulted in environmental degradation in the surrounding seas, and concern for the environment and its protection against pollutants is increasing. Identification of sources of contaminants and evaluation of current environmental status are essential to environmental pollution management, but relatively little has been done in the South China Sea (SCS). In order to investigate the abundance, distribution, and sources of Pb within the SCS, stable Pb isotopes and their ratios were employed to assess the contamination status and to differentiate between natural and anthropogenic origins of Pb in the surface sediments. The total Pb concentrations in sediments varied from 4.18 to 58.7 mg kg(-1), with an average concentration of 23.6 ± 8.9 mg kg(-1). The observed Pb isotope ratios varied from 18.039 to 19.211 for (206)Pb/(204)Pb, 15.228 to 16.080 for (207)Pb/(204)Pb, 37.786 to 39.951 for (208)Pb/(204)Pb, 1.176 to 1.235 for (206)Pb/(207)Pb, and 2.468 to 2.521 for (208)Pb/(207)Pb. The majority of these ratios are similar to those reported for natural detrital materials. Combined with Pb enrichment factor values, our results show that Pb found within most of the SCS sediments was mainly derived from natural sources, and that there was not significant Pb pollution from anthropogenic sources before 1998. Further studies are needed to reconstruct deposition history and for trend analysis.

  6. Next-to-leading order QCD predictions for Z,{gamma}*+3-jet distributions at the Tevatron

    SciTech Connect

    Berger, C. F.; Bern, Z.; Ita, H.; Dixon, L. J.; Gleisberg, T.; Febres Cordero, F.; Forde, D.; Kosower, D. A.; Maitre, D.

    2010-10-01

    Using BlackHat in conjunction with SHERPA, we have computed next-to-leading order QCD predictions for a variety of distributions in Z,{gamma}*+1, 2, 3-jet production at the Tevatron, where the Z boson or off-shell photon decays into an electron-positron pair. We find good agreement between the next-to-leading order results for jet p{sub T} distributions and measurements by CDF and D0. We also present jet-production ratios, or probabilities of finding one additional jet. As a function of vector-boson p{sub T}, the ratios have distinctive features which we describe in terms of a simple model capturing leading logarithms and phase-space and parton-distribution-function suppression.

  7. Transverse parton distribution functions at next-to-next-to-leading order: the quark-to-quark case.

    PubMed

    Gehrmann, Thomas; Lübbert, Thomas; Yang, Li Lin

    2012-12-14

    We present a calculation of the perturbative quark-to-quark transverse parton distribution function at next-to-next-to-leading order based on a gauge invariant operator definition. We demonstrate for the first time that such a definition works beyond the first nontrivial order. We extract from our calculation the coefficient functions relevant for a next-to-next-to-next-to-leading logarithmic Q(T) resummation in a large class of processes at hadron colliders.

  8. Leading Twist Parton Distribution Amplitudes in Heavy Flavor Pseudoscalar Mesons From Dyson-Schwinger Equations of QCD

    NASA Astrophysics Data System (ADS)

    Ding, Minghui; Gao, Fei; Chang, Lei; Liu, Yu-Xin; Roberts, Craig D.

    2016-03-01

    We compute the valence-quark leading twist parton distribution amplitudes (PDAs) of heavy pseudoscalar mesons ηc and ηb and find that they are both broader than the δ-like function while narrower than the asymptotic one. The evolution of distribution amplitude with momentum scale is then considered and PDAs will turn to a asymptotic form when the momentum goes to infinity.

  9. Influence of sea ice lead-width distribution on turbulent heat transfer between the ocean and the atmosphere

    NASA Astrophysics Data System (ADS)

    Marcq, S.; Weiss, J.

    2012-02-01

    Leads are linear-like structures of open water within the sea ice cover that develop as the result of fracturing due to divergence or shear. Through leads, air and water come into contact and directly exchange latent and sensible heat through convective processes driven by the large temperature and moisture differences between them. In the central Arctic, leads only cover 1 to 2% of the ocean during winter, but account for more than 70% of the upward heat fluxes. Furthermore, narrow leads (several meters) are more than twice as efficient at transmitting turbulent heat than larger ones (several hundreds of meters). We show that lead widths are power law distributed, P(X)~X-a with a>1, down to very small spatial scales (20 m or below). This implies that the open water fraction is by far dominated by very small leads. Using two classical formulations, which provide first order turbulence closure for the fetch-dependence of heat fluxes, we find that the mean heat fluxes (sensible and latent) over open water are up to 55% larger when considering the lead-width distribution obtained from a SPOT satellite image of the ice cover, compared to the situation where the open water fraction constitutes one unique large lead and the rest of the area is covered by ice, as it is usually considered in climate models at the grid scale. This difference may be even larger if we assume that the power law scaling of lead widths extends down to smaller (~1 m) scales. Such estimations may be a first step towards a subgrid scale parameterization of the spatial distribution of open water for heat fluxes calculations in ocean/sea ice coupled models.

  10. Laser ablation ICP-MS analysis of the radial distribution of lead in the femur of Alligator mississippiensis.

    PubMed

    Seltzer, Michael D; Lance, Valentine A; Elsey, Ruth M

    2006-06-15

    A laser ablation ICP-MS technique has been used to examine the radial distribution of lead in transverse sections of alligator femur. Annual bone growth in the femur results in the deposition of incremental layers of calcified tissue at the periphery of existing bone. Patterns of lead concentration within these layers provide a record of time-dependent accumulation from which exposure history can potentially be deduced. Femur specimens obtained from captive-reared alligators exhibited levels of lead accumulation that were entirely consistent with previously documented clinical signs of lead intoxication. In contrast, femurs obtained from wild alligators contained only minor amounts of lead that were likely accumulated as a result of incidental exposure.

  11. Laser ablation ICP-MS analysis of the radial distribution of lead in the femur of Alligator mississippiensis.

    PubMed

    Seltzer, Michael D; Lance, Valentine A; Elsey, Ruth M

    2006-06-15

    A laser ablation ICP-MS technique has been used to examine the radial distribution of lead in transverse sections of alligator femur. Annual bone growth in the femur results in the deposition of incremental layers of calcified tissue at the periphery of existing bone. Patterns of lead concentration within these layers provide a record of time-dependent accumulation from which exposure history can potentially be deduced. Femur specimens obtained from captive-reared alligators exhibited levels of lead accumulation that were entirely consistent with previously documented clinical signs of lead intoxication. In contrast, femurs obtained from wild alligators contained only minor amounts of lead that were likely accumulated as a result of incidental exposure. PMID:15982720

  12. Comparative Climate Responses of Anthropogenic Greenhouse Gases, All Major Aerosol Components, Black Carbon, and Methane, Accounting for the Evolution of the Aerosol Mixing State and of Clouds/Precipitation from Multiple Aerosol Size Distributions

    NASA Astrophysics Data System (ADS)

    Jacobson, M. Z.

    2005-12-01

    Several modeling studies to date have simulated the global climate response of anthropogenic greenhouse gases and bulk (non-size-resolved) sulfate or generic aerosol particles together, but no study has examined the climate response of greenhouse gases simultaneously with all major size- and composition resolved aerosol particle components. Such a study is important for improving our understanding of the effects of anthropogenic pollutants on climate. Here, the GATOR-GCMOM model is used to study the global climate response of (a) all major greenhouse gases and size-resolved aerosol components, (b) all major greenhouse gases alone, (c) fossil-fuel soot (black carbon, primary organic matter, sulfuric acid, bisulfate, sulfate), and (d) methane. Aerosol components treated in all simulations included water, black carbon, primary organic carbon, secondary organic carbon, sulfuric acid, bisulfate, sulfate, nitrate, chloride, ammonium, sodium, hydrogen ion, soil dust, and pollen/spores. Fossil-fuel soot (FFS) was emitted into its own size distribution. All other components, including biofuel and biomass soot, sea-spray, soil dust, etc., were emitted into a second distribution (MIX). The FFS distribution grew by condensation of secondary organic matter and sulfuric acid, hydration of water, and dissolution of nitric acid, ammonia, and hydrochloric acid. It self-coagulated and heterocoagulated with the MIX distribution, which also grew by condensation, hydration, and dissolution. Treatment of separate distributions for FFS allowed FFS to evolve from an external mixture to an internal mixture. In both distributions, black carbon was treated as a core component for optical calculations. Both aerosol distributions served as CCN during explicit size-resolved cloud formation. The resulting clouds grew by coagulation and condensation, coagulated with interstitial aerosol particles, and fell to the surface as rain and snow, carrying aerosol constituents with them. Thus, cloud

  13. Fostering the Capacity for Distributed Leadership: A Post-Heroic Approach to Leading School Improvement

    ERIC Educational Resources Information Center

    Klar, Hans W.; Huggins, Kristin Shawn; Hammonds, Hattie L.; Buskey, Frederick C.

    2016-01-01

    Principals are being encouraged to distribute leadership to increase schools' organizational capacities, and enhance student growth and learning. Extant research on distributed leadership practices provides an emerging basis for adopting such approaches. Yet, relatively less attention has been paid to examining the principal's role in fostering…

  14. Distributed Leadership in Action: Leading High-Performing Leadership Teams in English Schools

    ERIC Educational Resources Information Center

    Bush, Tony; Glover, Derek

    2012-01-01

    Heroic models of leadership based on the role of the principal have been supplemented by an emerging recognition of the value of "distributed leadership". The work of effective senior leadership teams (SLTs) is an important manifestation of distributed leadership, but there has been only limited research addressing the relationship between this…

  15. Anthropogenic Aerosols and Tropical Precipitation

    NASA Astrophysics Data System (ADS)

    Wang, C.; Kim, D.; Ekman, A. M. L.; Barth, M. C.; Rasch, P. J.

    2009-04-01

    Anthropogenic aerosols can affect the radiative balance of the Earth-atmosphere system and precipitation by acting as cloud condensation nuclei (CCN) or ice nuclei (IN) and thus modifying the optical and microphysical properties as well as lifetimes of clouds. Recent studies have also suggested that the direct radiative effect of anthropogenic aerosols, particularly absorbing aerosols, can perturb the large-scale circulation and cause a significant change in both quantity and distribution of critical tropical precipitation systems ranging from Pacific and Indian to Atlantic Oceans. This effect of aerosols on precipitation often appears in places away from aerosol-concentrated regions and current results suggest that the precipitation changes caused by it could be much more substantial than that by the microphysics-based aerosol effect. To understand the detailed mechanisms and strengths of such a "remote impact" and the climate response/feedback to anthropogenic aerosols in general, an interactive aerosol-climate model has been developed based on the Community Climate System Model (CCSM) of NCAR. Its aerosol module describes size, chemical composition, and mixing states of various sulfate and carbonaceous aerosols. Several model processes are derived based on 3D cloud-resolving model simulations. We have conducted a set of long integrations using the model driven by radiative effects of different combinations of various carbonaceous and sulfate aerosols and their mixtures. The responses of tropical precipitation systems to the forcing of these aerosols are analyzed using both model and observational data. Detailed analyses on the aerosol-precipitation causal relations of two systems: i.e., the Indian summer monsoon and Pacific ITCZ will be specifically presented.

  16. Geomorphology of anthropogenic landscapes

    NASA Astrophysics Data System (ADS)

    Sofia, Giulia; Tarolli, Paolo

    2015-04-01

    The construction of urban areas and the development of road networks leave a significant signature on the Earth surface, providing a geomorphological evidence to support the idea that humans are nowadays a geomorphic agent having deep effects on the morphological organization of the landscape. The reconstruction or identification of anthropogenic topographies, therefore, provides a mechanism for quantifying anthropogenic changes to the landscape systems in the Anthropocene. Following this research line, the present study tests the effectiveness of a recently published topographic index, the Slope Local Length of Autocorrelation (SLLAC, Sofia et al. 2014) to portrait anthropogenic geomorphology, focusing in particular on road network density, and urban complexity (UCI). At first, the research considers the increasing of anthropic structures and the resulting changes in the SLLAC and in two derived parameters (mean SLLAC per km2 and SLLAC roughness, or Surface Peak Curvature -Spc). As a second step, considering the SLLAC derived indices, the anthropogenic geomorphology is automatically depicted using a k-means clustering algorithm. In general, the increasing of road network density or of the UCI is positively correlated to the mean SLLAC per km2, while the Spc is negatively correlated to the increasing of the anthropic structures. Areas presenting different road network organization are effectively captured considering multiple combinations of the defined parameters. Landscapes with small scattered towns, and a network with long roads in a dendritic shape (with hierarchical branching) are characterized simultaneously by high mean SLLAC and low Spc. Large and complex urban areas served by rectilinear networks with numerous short straight lines and right angles, have either a maximized mean SLLAC or a minimized Spc or both. In all cases, the anthropogenic landscape identified by the procedure is comparable to the ones identified manually from orthophoto, with the

  17. The study of lead content distribution in Chinese seafood and its oral bioavailability in mice.

    PubMed

    Tong, Yongpeng; Zhu, Zhipeng; Hao, Xin; He, Long; He, Weibiao; Chen, Jianmin

    2016-01-01

    Using inductively coupled plasma mass spectrometry (ICP-MS), the lead concentrations and isotope ratios of 32 kinds of seafood collected from local markets of China were measured. Among these seafoods, the highest concentrations of lead were found in Patinopecten yessoensis and Mugil cephalus, which were 2.94 ± 0.40 and 2.02 ± 0.26 μg g(-1) of dry weight, respectively. Pb concentration was found to be higher in benthic fish than in other fish. The result indicated that lead concentrations in some seafood exceeded the maximum levels of Pb in foods proposed by European Commission (EC). Nine species of cooked seafood were chosen to feed mice (35-38 g). The result showed that Pb oral bioavailability of cooked seafood in vivo was below 10%. Furthermore, oral bioavailability of the same lead-containing seafood increased greatly in pregnant mice compared with non-pregnant mice.

  18. Random Tree-Puzzle leads to the Yule-Harding distribution.

    PubMed

    Vinh, Le Sy; Fuehrer, Andrea; von Haeseler, Arndt

    2011-02-01

    Approaches to reconstruct phylogenies abound and are widely used in the study of molecular evolution. Partially through extensive simulations, we are beginning to understand the potential pitfalls as well as the advantages of different methods. However, little work has been done on possible biases introduced by the methods if the input data are random and do not carry any phylogenetic signal. Although Tree-Puzzle (Strimmer K, von Haeseler A. 1996. Quartet puzzling: a quartet maximum-likelihood method for reconstructing tree topologies. Mol Biol Evol. 13:964-969; Schmidt HA, Strimmer K, Vingron M, von Haeseler A. 2002. Tree-Puzzle: maximum likelihood phylogenetic analysis using quartets and parallel computing. Bioinformatics 18:502-504) has become common in phylogenetics, the resulting distribution of labeled unrooted bifurcating trees when data do not carry any phylogenetic signal has not been investigated. Our note shows that the distribution converges to the well-known Yule-Harding distribution. However, the bias of the Yule-Harding distribution will be diminished by a tiny amount of phylogenetic information. maximum likelihood, phylogenetic reconstruction, Tree-Puzzle, tree distribution, Yule-Harding distribution.

  19. Potential sources and racial disparities in the residential distribution of soil arsenic and lead among pregnant women.

    PubMed

    Davis, Harley T; Aelion, C Marjorie; Liu, Jihong; Burch, James B; Cai, Bo; Lawson, Andrew B; McDermott, Suzanne

    2016-05-01

    Exposure to arsenic (As) or lead (Pb) has been associated with adverse health outcomes, and high-risk populations can be disproportionately exposed to these metals in soils. The objectives of this study were: to examine if predicted soil As and Pb concentrations at maternal residences of South Carolina (SC) low-income mothers differed based on maternal race (non-Hispanic black versus white), to examine whether differences in predicted residential soil As and Pb concentrations among black and white mothers differed by socioeconomic status (SES), and to examine whether such disparities persisted after controlling for anthropogenic sources of these metals, including direction from, and distance to industrial facilities. Kriged soil As and Pb concentrations were estimated at maternal residences in 11 locations in SC, and models with maternal race and individual and US Census block group level SES measures were examined. US Environmental Protection Agency Toxics Release Inventory (TRI) facility As and Pb releases categorized by distance and direction to block groups in which mothers resided were also identified, as were proxy measures for historic use of leaded gasoline (road density) and Pb-based paint (categories of median year home built by US Census block group). Consistent racial disparities were observed for predicted residential soil As and Pb concentrations, and the disparity was stronger for Pb than As (betas from adjusted models for black mothers were 0.12 and 2.2 for As and Pb, respectively, all p<0.006). Higher road density and older homes in block groups were more closely associated with higher predicted soil As and Pb concentrations than on-site releases of As and Pb categorized by facility location. These findings suggest that non-Hispanic black mothers in this study population had elevated residential As and Pb soil concentrations, after adjusting for SES, and that soil As and Pb concentrations were not associated with recent industrial releases. PMID

  20. Revisiting the Benford law: When the Benford-like distribution of leading digits in sets of numerical data is expectable?

    NASA Astrophysics Data System (ADS)

    Whyman, G.; Ohtori, N.; Shulzinger, E.; Bormashenko, Ed.

    2016-11-01

    The Benford law states that the frequencies of decimal digits at the first place of numbers corresponding to various kinds of statistical or experimental data are not equal changing from 0.3 for 1 to 0.04 for 9. The corresponding frequencies' distribution is described by the logarithmic function. As is shown in the present article, the Benford distribution is a particular case of a more general mathematical statement. Namely, if a function describing the dependence between two measurable quantities has a positive second derivative, then the mentioned above frequencies decrease for digits from 1 to 9. The exact Benford distribution is valid for the exponential function only. Explicit expressions for frequencies of leading digits are obtained and specified for the power, logarithmic, and tangent functions as examples. The kinematic experiment was performed to illustrate the above results. Also the tabulated data on thermal conductivities of liquids confirm the proposed formula for frequencies' distribution.

  1. Anthropogenic modification of the oceans.

    PubMed

    Tyrrell, Toby

    2011-03-13

    Human activities are altering the ocean in many different ways. The surface ocean is warming and, as a result, it is becoming more stratified and sea level is rising. There is no clear evidence yet of a slowing in ocean circulation, although this is predicted for the future. As anthropogenic CO(2) permeates into the ocean, it is making sea water more acidic, to the detriment of surface corals and probably many other calcifiers. Once acidification reaches the deep ocean, it will become more corrosive to CaCO(3), leading to a considerable reduction in the amount of CaCO(3) accumulating on the deep seafloor. There will be a several thousand-year-long interruption to CaCO(3) sedimentation at many points on the seafloor. A curious feedback in the ocean, carbonate compensation, makes it more likely that global warming and sea-level rise will continue for many millennia after CO(2) emissions cease.

  2. Diagnosis and Design for School Improvement: Using a Distributed Perspective to Lead and Manage Change

    ERIC Educational Resources Information Center

    Spillane, James P.; Coldren, Amy Franz

    2011-01-01

    This practical resource highlights the critical importance of diagnosis and design in the work of leading and managing for school improvement. The authors maintain that today's school leaders and managers, under intense pressure to improve student learning, cannot simply adopt and implement pre-packaged reforms manufactured outside the school.…

  3. Spatial and temporal distributions of Secchi depths and chlorophyll a concentrations in the Suo Nada of the Seto Inland Sea, Japan, exposed to anthropogenic nutrient loading.

    PubMed

    Nishijima, Wataru; Umehara, Akira; Sekito, Satoshi; Okuda, Tetsuji; Nakai, Satoshi

    2016-11-15

    Thirty years of monitoring data were used to elucidate the spatial and temporal distributions of Secchi depths in the Suo Nada (Suo Sea) and to evaluate how chlorophyll a concentration and reductions of nutrient loading from the watershed affected those distributions. Secchi depths throughout the Suo Nada were positively correlated with water depths. The spatial and temporal variations of Secchi depths could be explained by variations of phytoplankton biomass in areas where the water depth exceeded 20m, but in areas shallower than 10m, other factors affecting light attenuation beside phytoplankton, which include suspended particulate matter and chromophoric dissolved organic matter, obscured relationships between phytoplankton biomass and Secchi depths. Phosphorus limited phytoplankton biomass in the Suo Nada. The main source of allochthonous phosphorus from the 1980s to the 1990s was the watershed. Because of significant reductions of nutrient loading from the watershed, the Pacific Ocean will most likely be the principal source of allochthonous phosphorus after around 2000, except in areas shallower than 10m. PMID:27395073

  4. Distribution and transport of selected anthropogenic organic compounds on Mississippi River suspended sediment (U.S.A.), May/June 1988

    USGS Publications Warehouse

    Rostad, C.E.; Pereira, W.E.; Leiker, T.J.

    1994-01-01

    The distribution and transport of selected hydrophobic halogenated organic compounds on suspended sediment from the lower Mississippi River were determined using discharge-weighted sampling with concurrent discharge measurements. Trends in compound concentration from upstream to downstream and the effects of selected tributaries were determined. The compounds identified on the suspended sediment include pentachlorobenzene, hexachlorobenzene, pentachloroanisole, dacthal, chlordane (trans-), nonachlor (trans-), chlorthalonil, and penta-, hexa-, hepta- and octachlorobiphenyls. Loads of most of the compounds increased from upstream to downstream on the main stem of the Mississippi River. Of the tributaries studied, the Ohio River had the most significant effect on the loads.The distribution and transport of selected hydrophobic halogenated organic compounds on suspended sediment from the lower Mississippi River were determined using discharge-weighted sampling with concurrent discharge measurements. Trends in compound concentration from upstream to downstream and the effects of selected tributaries were determined. The compounds identified on the suspended sediment include pentachlorobenzene, hexachlorobenzene, pentachloroanisole, dacthal, chlordane (trans-), nonachlor (trans-), chlorthalonil, and penta-, hexa-, hepta- and octachlorobiphenyls. Loads of most of the compounds increased from upstream to downstream on the main stem of the Mississippi River. Of the tributaries studied, the Ohio River had the most significant effect on the loads.

  5. Spatial and temporal distributions of Secchi depths and chlorophyll a concentrations in the Suo Nada of the Seto Inland Sea, Japan, exposed to anthropogenic nutrient loading.

    PubMed

    Nishijima, Wataru; Umehara, Akira; Sekito, Satoshi; Okuda, Tetsuji; Nakai, Satoshi

    2016-11-15

    Thirty years of monitoring data were used to elucidate the spatial and temporal distributions of Secchi depths in the Suo Nada (Suo Sea) and to evaluate how chlorophyll a concentration and reductions of nutrient loading from the watershed affected those distributions. Secchi depths throughout the Suo Nada were positively correlated with water depths. The spatial and temporal variations of Secchi depths could be explained by variations of phytoplankton biomass in areas where the water depth exceeded 20m, but in areas shallower than 10m, other factors affecting light attenuation beside phytoplankton, which include suspended particulate matter and chromophoric dissolved organic matter, obscured relationships between phytoplankton biomass and Secchi depths. Phosphorus limited phytoplankton biomass in the Suo Nada. The main source of allochthonous phosphorus from the 1980s to the 1990s was the watershed. Because of significant reductions of nutrient loading from the watershed, the Pacific Ocean will most likely be the principal source of allochthonous phosphorus after around 2000, except in areas shallower than 10m.

  6. THE OCCURRENCE OF CONTAMINANT ACCUMULATION IN LEAD PIPE SCALES FROM DOMESTIC DRINKING WATER DISTRIBUTION SYSTEMS

    EPA Science Inventory

    Previous work has shown that contaminants, such as Al, As and Ra, can accumulate in drinking water distribution system solids. The release of accumulated contaminants back into the water supply could result in elevated levels at consumers’ taps, and current monitoring practices d...

  7. Lead and other metals distribution in local cooking salt from the Fofi salt- spring in Akwana, Middle Benue Trough, Nigeria

    SciTech Connect

    Dim, L.A.; Kinyua, A.M.; Munyithya, J.M.; Adetunji, J. )

    1991-06-01

    Energy Dispersive X-ray Fluorescence (EDXRF) technique has been used to determine the concentrations of lead(Pb) and other heavy metals in local cooking salts (LCS) from Akwana village, Middle Benue Trough, Nigeria. The comparison of the distribution of these metals in LCS, fake salt (FS) and the usual common salts (CS) are given. Lead was found to be enriched in LCS by factor exceeding 200 times compared to the other salts. The origin of Pb contamination in the LCS is examined and its effects on the inhabitants of the village are considered.

  8. Lead in the environment

    USGS Publications Warehouse

    Pattee, O.H.; Pain, D.J.; Hoffman, David J.; Rattner, Barnett A.; Burton, G. Allen; Cairns, John=

    2003-01-01

    Anthropogenic uses of lead have probably altered its availability and environmental distribution more than any other toxic element. Consequently, lead concentrations in many living organisms may be approaching thresholds of toxicity for the adverse effects of lead. Such thresholds are difficult to define, as they vary with the chemical and physical form of lead, exposure regime, other elements present and also vary both within and between species. The technological capability to accurately quantify low lead concentrations has increased over the last decade, and physiological and behavioral effects have been measured in wildlife with tissue lead concentrations below those previously considered safe for humans.s.236 Consequently. lead criteria for the protection of wildlife and human health are frequently under review, and 'thresholds' of lead toxicity are being reconsidered. Proposed lead criteria for the protection of natural resources have been reviewed by Eisler. Uptake of lead by plants is limited by its generally low availability in soils and sediments, and toxicity may be limited by storage mechanisms and its apparently limited translocation within most plants. Lead does not generally accumulate within the foliar parts of plants, which limits its transfer to higher trophic levels. Although lead may concentrate in plant and animal tissues, no evidence of biomagnification exists. Acid deposition onto surface waters and soils with low buffering capacity may influence the availability of lead for uptake by plants and animals, and this may merit investigation at susceptible sites. The biological significance of chronic low-level lead exposure to wildlife is sometimes difficult to quantify. Animals living in urban environments or near point sources of lead emission are inevitably subject to greater exposure to lead and enhanced risk of lead poisoning. Increasingly strict controls on lead emissions in many countries have reduced exposure to lead from some sources

  9. [Regularities of lateral distribution of uranium and thorium decay series radionuclides in the anthropogenically changed soils from the area of radium production waste storage].

    PubMed

    Evseeva, T I; Belykh, E S; Maĭstrenko, T A; Geras'kin, S A; Taskaev, A I; Vakhrusheva, O M

    2012-01-01

    Cartographical investigations of the territory of radium production waste storage has shown some changes in lateral differentiation of radionuclides of uranium and thorium decay series to occur during 27 years (1981-2008). Those changes are caused mostly by flat denudation typical for fluvial terrace. At present radionuclides of uranium and thorium decay series are concentrated mostly in flood lands and relief depressions. At the same time, decrease in the radionuclide activity concentration in 0-20 cm soil layer is observed with changes in lateral distribution. Total stocks of 226Ra, 210Pb and 210Po within catena soils studied in the northern and southern parts of the waste storage decreased 3-6 times, 238U - 2 times, and did not significantly change in case of 232Th during 27 years. Nonetheless, most of the samples studied are referred to radioactive waste both according to Russian standards (SPORO-2002) and IAEA safety norms (IAEA, 2004).

  10. [Regularities of lateral distribution of uranium and thorium decay series radionuclides in the anthropogenically changed soils from the area of radium production waste storage].

    PubMed

    Evseeva, T I; Belykh, E S; Maĭstrenko, T A; Geras'kin, S A; Taskaev, A I; Vakhrusheva, O M

    2012-01-01

    Cartographical investigations of the territory of radium production waste storage has shown some changes in lateral differentiation of radionuclides of uranium and thorium decay series to occur during 27 years (1981-2008). Those changes are caused mostly by flat denudation typical for fluvial terrace. At present radionuclides of uranium and thorium decay series are concentrated mostly in flood lands and relief depressions. At the same time, decrease in the radionuclide activity concentration in 0-20 cm soil layer is observed with changes in lateral distribution. Total stocks of 226Ra, 210Pb and 210Po within catena soils studied in the northern and southern parts of the waste storage decreased 3-6 times, 238U - 2 times, and did not significantly change in case of 232Th during 27 years. Nonetheless, most of the samples studied are referred to radioactive waste both according to Russian standards (SPORO-2002) and IAEA safety norms (IAEA, 2004). PMID:22568020

  11. The leading twist light-cone distribution amplitudes for the S-wave and P-wave Bc mesons

    NASA Astrophysics Data System (ADS)

    Xu, Ji; Yang, Deshan

    2016-07-01

    The light-cone distribution amplitudes (LCDAs) serve as important nonperturbative inputs for the study of hard exclusive processes. In this paper, we calculate ten LCDAs at twist-2 for the S-wave and P-wave B c mesons up to the next-to-leading order (NLO) of the strong coupling α s and leading order of the velocity expansion. Each one of these ten LCDAs is expressed as a product of a perturbatively calculable distribution and a universal NRQCD matrix-element. By use of the spin symmetry, only two NRQCD matrix-elements will be involved. The reduction of the number of non-perturbative inputs will improve the predictive power of collinear factorization.

  12. Lead in ancient Rome's city waters.

    PubMed

    Delile, Hugo; Blichert-Toft, Janne; Goiran, Jean-Philippe; Keay, Simon; Albarède, Francis

    2014-05-01

    It is now universally accepted that utilization of lead for domestic purposes and water distribution presents a major health hazard. The ancient Roman world was unaware of these risks. How far the gigantic network of lead pipes used in ancient Rome compromised public health in the city is unknown. Lead isotopes in sediments from the harbor of Imperial Rome register the presence of a strong anthropogenic component during the beginning of the Common Era and the Early Middle Ages. They demonstrate that the lead pipes of the water distribution system increased Pb contents in drinking water of the capital city by up to two orders of magnitude over the natural background. The Pb isotope record shows that the discontinuities in the pollution of the Tiber by lead are intimately entwined with the major issues affecting Late Antique Rome and its water distribution system.

  13. Lead in ancient Rome's city waters.

    PubMed

    Delile, Hugo; Blichert-Toft, Janne; Goiran, Jean-Philippe; Keay, Simon; Albarède, Francis

    2014-05-01

    It is now universally accepted that utilization of lead for domestic purposes and water distribution presents a major health hazard. The ancient Roman world was unaware of these risks. How far the gigantic network of lead pipes used in ancient Rome compromised public health in the city is unknown. Lead isotopes in sediments from the harbor of Imperial Rome register the presence of a strong anthropogenic component during the beginning of the Common Era and the Early Middle Ages. They demonstrate that the lead pipes of the water distribution system increased Pb contents in drinking water of the capital city by up to two orders of magnitude over the natural background. The Pb isotope record shows that the discontinuities in the pollution of the Tiber by lead are intimately entwined with the major issues affecting Late Antique Rome and its water distribution system. PMID:24753588

  14. Serum immunoglobulins and lymphocyte subset distributions in children and adults living in communities assessed for lead and cadmium exposure

    SciTech Connect

    Sarasua, S.M.; Vogt, R.F.; Henderson, L.O.; Jones, P.A.; Lybarger, J.A.

    2000-05-12

    This study assessed the impact of environmental cadmium and lead exposure on the immune system of more than 2,000 children and adults. Serum immunoglobulins [immunoglobulins (lg) A, G, and M] and peripheral blood lymphocyte phenotypes (T cells, B cells, NK cells, and CD4/CD8 subsets) were measured in a total of 2041 children and adults who lived either in sites with elevated soil levels of cadmium and lead (n = 1,561) or in comparison communities (n = 480). The blood lead and urine cadmium levels of participants were somewhat higher than national average mean blood lead levels were 7 {micro}g/dl for participants aged 6--35 mo; 6 {micro}g/dl for participants aged 36--71 mo, 4 {micro}g/dl for participants aged 6--15 yr; and 4.3 {micro}g/dl for participants aged 16--75 yr. Multivariate analysis indicated no marked differences in any of the immune marker distributions attributed to lead for adults or children over 3 yr of age. However, in children under age 3, increased blood lead levels, principally those over 15 {micro}g/dl were associated with increases in IgA, IgC, IgM, and circulating B/lymphocytes. Youth adults urine cadmium levels over 1.5 {micro}g/g were associated with higher levels of IgA and circulating B.

  15. Distribution of metals and accumulation of lead by different tissues in the freshwater snail Lymnaea stagnalis (L.)

    SciTech Connect

    Pyatt, F.B.; Pyatt, A.J.; Pentreath, V.W.

    1997-07-01

    The concentrations of several metals in different body tissues of the freshwater snail, Lymnaea stagnalis (L.), collected from an uncontaminated environment, were measured by electron probe X-ray microanalysis. Significant concentrations of the potentially toxic elements manganese, titanium, and copper were detected in all tissues, although they were not detectable in the water sampled at collection; bioaccumulation is thus evidenced. Highest concentrations of manganese and copper were present in the shell, while highest concentrations of titanium were present in the head and foot. Experimental snails were continuously exposed to lead chloride (lead at 5 ppm) for an experimental period of 3 weeks. Both elements were accumulated to different extents by the snail tissues but with high concentrations again in the head of the animals, and chloride also in the visceral hump. No significant alterations in the distribution of the other elements measured were observed in the lead chloride-exposed animals.

  16. Laboratory studies investigating the processes leading to discolouration in water distribution networks.

    PubMed

    Husband, P S; Boxall, J B; Saul, A J

    2008-10-01

    Results are reported from laboratory experiments conducted to investigate the processes of discolouration within a water distribution system and specifically the concepts underpinning an empirical model proposed by Boxall et al. [Boxall, J.B., Saul, A.J., Skipworth, P.J., 2001. A novel approach to modelling sediment movement in distribution mains based on particle characteristics. Water Software Systems 1, 263-273.] and field validated by Boxall and Saul [Boxall, J.B., Saul, A.J., 2005. Modelling discolouration in potable water distribution systems. Journal of Environmental Engineering ASCE 131(5).]. The model is based on the hypothesis that discolouration is caused by the erosion and transport of fine particles, typically dominated by iron and manganese in the UK, that are attached to the pipe walls of the system by forces in addition to self-weight. These particles display cohesive-like properties and build up in layers on the pipe wall, conditioned by the usual daily flow patterns within the system. Discolouration events are caused by erosion of these layers due to changes in the system hydraulics and specifically changes in shear stress at the pipe wall, for example due to change in demand, a burst or the opening of a fire hydrant. Once cleaned from the pipe walls the layers re-accumulate under the usual conditions within the system. Experiments to determine cohesive layer behaviour and strength characteristics involved development periods followed by the measurement of the resultant discolouration when accumulated material was eroded by an increase in pipe-wall shear stress. The results support the empirical model concepts and hence its application. The results also suggest that the generation of material layers is influenced by the range of daily flow patterns, with greater variability reducing material accumulation, but not by the magnitude of steady state hydraulic conditions. PMID:18775550

  17. Laboratory studies investigating the processes leading to discolouration in water distribution networks.

    PubMed

    Husband, P S; Boxall, J B; Saul, A J

    2008-10-01

    Results are reported from laboratory experiments conducted to investigate the processes of discolouration within a water distribution system and specifically the concepts underpinning an empirical model proposed by Boxall et al. [Boxall, J.B., Saul, A.J., Skipworth, P.J., 2001. A novel approach to modelling sediment movement in distribution mains based on particle characteristics. Water Software Systems 1, 263-273.] and field validated by Boxall and Saul [Boxall, J.B., Saul, A.J., 2005. Modelling discolouration in potable water distribution systems. Journal of Environmental Engineering ASCE 131(5).]. The model is based on the hypothesis that discolouration is caused by the erosion and transport of fine particles, typically dominated by iron and manganese in the UK, that are attached to the pipe walls of the system by forces in addition to self-weight. These particles display cohesive-like properties and build up in layers on the pipe wall, conditioned by the usual daily flow patterns within the system. Discolouration events are caused by erosion of these layers due to changes in the system hydraulics and specifically changes in shear stress at the pipe wall, for example due to change in demand, a burst or the opening of a fire hydrant. Once cleaned from the pipe walls the layers re-accumulate under the usual conditions within the system. Experiments to determine cohesive layer behaviour and strength characteristics involved development periods followed by the measurement of the resultant discolouration when accumulated material was eroded by an increase in pipe-wall shear stress. The results support the empirical model concepts and hence its application. The results also suggest that the generation of material layers is influenced by the range of daily flow patterns, with greater variability reducing material accumulation, but not by the magnitude of steady state hydraulic conditions.

  18. Lead distribution and possible sources along vertical zone spectrum of typical ecosystems in the Gongga Mountain, eastern Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    Luo, Ji; Tang, Ronggui; Sun, Shouqin; Yang, Dandan; She, Jia; Yang, Peijun

    2015-08-01

    A total of 383 samples from soil, plant, litterfall and precipitation in four typical ecosystems of Gongga Mountain were collected. Pb concentrations of samples were measured and analyzed. The results showed mean Pb concentrations in different soil layers were in the order of O > A > C, and mean Pb concentrations of the aboveground parts of plant was 3.60 ± 2.54 mg kg-1, with the minimum value of 0.77 mg kg-1 and the maximum value of 10.90 mg kg-1. Pb concentrations in soil's O-horizon and A-horizon showed a downward trend with increasing elevation (the determination coefficient R2 was 0.9478, 0.7918 and 0.9759 respectively). In contrast to other soil layers, the level of Pb concentrations in O-horizon (incomplete decomposition) was significantly high. Litterfall decomposition, atmospheric deposition and the unique climate could be main factors leading high Pb accumulation in soil's O-horizon. What's more, significant correlation (R2 = 0.8126, P < 0.05) was found between Pb concentrations in fine roots and soil's A-horizon confirms that fine roots could adsorb and accumulate Pb materials in soil. In general, the fact that Pb inputted into the typical ecosystems in the Gongga Mountain via long-range transportation and deposition of the atmosphere from external Pb sources could be confirmed by the HYSPLIT model and the ratio of CPb/CAl in plants (leaves) and CPb/CAl in litterfall. The mining activities and increasing anthropogenic activities (tourism development) could be main sources of Pb in this area. In order to better understand Pb sources and eco-risks of these typical ecosystems, litterfall decomposition characteristics, biomass of productivity of forest ecosystem, Pb isotopic tracing among air mass, twigs, leaves, litterfall and O-horizon soil in this vertical belt should also be taken into consideration.

  19. Anthropogenic climate change

    SciTech Connect

    Budyko, M.I.; Izreal, Yu.A.

    1991-01-01

    The climate modeling community would agree that the present generation of theoretical models cannot adequately answer important question about the climatic implications of increasing concentrations of CO[sub 2] and other greenhouse gases. Society, however, is presently deciding by its action, or inaction, the policies that will deal with the extent and results of our collective flatulence. In this situation, an engineering approach to estimating the developing pattern of anthropogenic climate change is appropriate. For example, Budyko has argued that, while scientists may have made great advances in modelling the flow around an airfoil, engineers make extensive use of empirical equations and measurements to design airplanes that fly. Budyko and Izreal have produced an encyclopedic treatise summarizing the results of Soviet researchers in applying empirical and semiempirical methods to estimating future climatic patterns, and some of their ensuring effects. These techniques consist mainly of statistical relationships derived from 1850-1950 network data and of patterns revealed by analysis of paleoclimatic data. An important part of the Soviet effort in anthropogenic climate-change studies is empirical techniques that represent independent verification of the results of theoretical climate models.

  20. Discrete Step Sizes of Molecular Motors Lead to Bimodal Non-Gaussian Velocity Distributions under Force

    NASA Astrophysics Data System (ADS)

    Vu, Huong T.; Chakrabarti, Shaon; Hinczewski, Michael; Thirumalai, D.

    2016-08-01

    Fluctuations in the physical properties of biological machines are inextricably linked to their functions. Distributions of run lengths and velocities of processive molecular motors, like kinesin-1, are accessible through single-molecule techniques, but rigorous theoretical models for these probabilities are lacking. Here, we derive exact analytic results for a kinetic model to predict the resistive force (F )-dependent velocity [P (v )] and run length [P (n )] distribution functions of generic finitely processive molecular motors. Our theory quantitatively explains the zero force kinesin-1 data for both P (n ) and P (v ) using the detachment rate as the only parameter. In addition, we predict the F dependence of these quantities. At nonzero F , P (v ) is non-Gaussian and is bimodal with peaks at positive and negative values of v , which is due to the discrete step size of kinesin-1. Although the predictions are based on analyses of kinesin-1 data, our results are general and should hold for any processive motor, which walks on a track by taking discrete steps.

  1. Discrete Step Sizes of Molecular Motors Lead to Bimodal Non-Gaussian Velocity Distributions under Force.

    PubMed

    Vu, Huong T; Chakrabarti, Shaon; Hinczewski, Michael; Thirumalai, D

    2016-08-12

    Fluctuations in the physical properties of biological machines are inextricably linked to their functions. Distributions of run lengths and velocities of processive molecular motors, like kinesin-1, are accessible through single-molecule techniques, but rigorous theoretical models for these probabilities are lacking. Here, we derive exact analytic results for a kinetic model to predict the resistive force (F)-dependent velocity [P(v)] and run length [P(n)] distribution functions of generic finitely processive molecular motors. Our theory quantitatively explains the zero force kinesin-1 data for both P(n) and P(v) using the detachment rate as the only parameter. In addition, we predict the F dependence of these quantities. At nonzero F, P(v) is non-Gaussian and is bimodal with peaks at positive and negative values of v, which is due to the discrete step size of kinesin-1. Although the predictions are based on analyses of kinesin-1 data, our results are general and should hold for any processive motor, which walks on a track by taking discrete steps. PMID:27564000

  2. Detection of anthropogenic dust using CALIPSO lidar measurements

    NASA Astrophysics Data System (ADS)

    Huang, J.; Liu, J.; Chen, B.; Nasiri, S. L.

    2015-04-01

    Anthropogenic dusts are those produced by human activities on disturbed soils, which are mainly cropland, pasture, and urbanized regions and are a subset of the total dust load which includes natural sources from desert regions. Our knowledge of anthropogenic dusts is still very limited due to a lack of data on source distribution and magnitude, and on their effect on radiative forcing which may be comparable to other anthropogenic aerosols. To understand the contribution of anthropogenic dust to the total global dust load and its effect on radiative transfer and climate, it is important to identify them from total dust. In this study, a new technique for distinguishing anthropogenic dust from natural dust is proposed by using Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) dust and planetary boundary layer (PBL) height retrievals along with a land use dataset. Using this technique, the global distribution of dust is analyzed and the relative contribution of anthropogenic and natural dust sources to regional and global emissions are estimated. Results reveal that local anthropogenic dust aerosol due to human activity, such as agriculture, industrial activity, transportation, and overgrazing, accounts for about 25% of the global continental dust load. Of these anthropogenic dust aerosols, more than 53% come from semi-arid and semi-wet regions. Annual mean anthropogenic dust column burden (DCB) values range from 0.42 g m-2 with a maximum in India to 0.12 g m-2 with a minimum in North America. A better understanding of anthropogenic dust emission will enable us to focus on human activities in these critical regions and with such knowledge we will be better able to improve global dust models and to explore the effects of anthropogenic emission on radiative forcing, climate change and air quality in the future.

  3. Lead (Pb) and other metals in New York City community garden soils: factors influencing contaminant distributions

    PubMed Central

    Mitchell, Rebecca G.; Spliethoff, Henry M.; Ribaudo, Lisa N.; Lopp, Donna M.; Shayler, Hannah A.; Marquez-Bravo, Lydia G.; Lambert, Veronique T.; Ferenz, Gretchen S.; Russell-Anelli, Jonathan M.; Stone, Edie B.; McBride, Murray B.

    2014-01-01

    Urban gardens provide affordable fresh produce to communities with limited access to healthy food but may also increase exposure to lead (Pb) and other soil contaminants. Metals analysis of 564 soil samples from 54 New York City (NYC) community gardens found at least one sample exceeding health-based guidance values in 70% of gardens. However, most samples (78%) did not exceed guidance values, and medians were generally below those reported in NYC soil and other urban gardening studies. Barium (Ba) and Pb most frequently exceeded guidance values and along with cadmium (Cd) were strongly correlated with zinc (Zn), a commonly measured nutrient. Principal component analysis suggested that contaminants varied independently from organic matter and geogenic metals. Contaminants were associated with visible debris and a lack of raised beds; management practices (e.g., importing uncontaminated soil) have likely reduced metals concentrations. Continued exposure reduction efforts would benefit communities already burdened by environmental exposures. PMID:24502997

  4. Altered Arachidonate Distribution in Macrophages from Caveolin-1 Null Mice Leading to Reduced Eicosanoid Synthesis*

    PubMed Central

    Astudillo, Alma M.; Pérez-Chacón, Gema; Meana, Clara; Balgoma, David; Pol, Albert; del Pozo, Miguel A.; Balboa, María A.; Balsinde, Jesús

    2011-01-01

    In this work we have studied the effect of caveolin-1 deficiency on the mechanisms that regulate free arachidonic acid (AA) availability. The results presented here demonstrate that macrophages from caveolin-1-deficient mice exhibit elevated fatty acid incorporation and remodeling and a constitutively increased CoA-independent transacylase activity. Mass spectrometry-based lipidomic analyses reveal stable alterations in the profile of AA distribution among phospholipids, manifested by reduced levels of AA in choline glycerophospholipids but elevated levels in ethanolamine glycerophospholipids and phosphatidylinositol. Furthermore, macrophages from caveolin-1 null mice show decreased AA mobilization and prostaglandin E2 and LTB4 production upon cell stimulation. Collectively, these results provide insight into the role of caveolin-1 in AA homeostasis and suggest an important role for this protein in the eicosanoid biosynthetic response. PMID:21852231

  5. Cultivar variations in cadmium and lead accumulation and distribution among 30 wheat (Triticum aestivum L.) cultivars.

    PubMed

    Liu, Weitao; Liang, Lichen; Zhang, Xue; Zhou, Qixing

    2015-06-01

    In recent years, heavy metal pollution in agricultural soil in China has received public concern. The concept of low-accumulation cultivars (LACs) was proposed to minimize the influx of pollutants to the human food chain. Variations in Cd and Pb accumulation, distribution, and tolerance among 30 wheat (Triticum aestivum L.) cultivars were studied in a hydroponic experiment to preliminary identify LACs of Cd or Pb for further field experiments. Of the 30 wheat cultivars tested, 27 and 26 wheat cultivars showed no effect of the Cd/Pb treatments on the shoot and root biomass, respectively. The results showed that the tested wheat cultivars had considerable tolerance to Cd and Pb toxicity. Significant (p < 0.05) differences in shoot Cd concentration were observed among the tested wheat cultivars under treatments Cd1.0 and Cd1.0Pb15, ranging from 0.91 to 6.74 and from 0.87 to 5.96, with the mean of 3.83 and 2.94 mg kg(-1) DW, respectively. Significant (p < 0.05) differences in shoot Pb concentration were also observed among the tested wheat cultivars under treatments Pb15 and Cd1.0Pb15, ranging from 22.18 to 94.03 and from 18.30 to 76.88, with the mean of 50.38 and 41.20 mg kg(-1) DW, respectively. Low accumulation and internal distribution may both affect the cultivar differences in Cd and Pb accumulation in wheat shoots. Overall, wheat cultivars LF-13, LF-16, and LF-21 had lower Cd-accumulating abilities in their shoots. Wheat cultivars LF-13, LF-23, LF-26, and LF-27 showed low Pb accumulation characteristics in their shoots. An antagonistic interaction occurred between Cd and Pb in accumulation in wheat roots and shoots, which will be further studied in field experiments.

  6. Reexamining cluster radioactivity in trans-lead nuclei with consideration of specific density distributions in daughter nuclei and clusters

    NASA Astrophysics Data System (ADS)

    Qian, Yibin; Ren, Zhongzhou; Ni, Dongdong

    2016-08-01

    We further investigate the cluster emission from heavy nuclei beyond the lead region in the framework of the preformed cluster model. The refined cluster-core potential is constructed by the double-folding integral of the density distributions of the daughter nucleus and the emitted cluster, where the radius or the diffuseness parameter in the Fermi density distribution formula is determined according to the available experimental data on the charge radii and the neutron skin thickness. The Schrödinger equation of the cluster-daughter relative motion is then solved within the outgoing Coulomb wave-function boundary conditions to obtain the decay width. It is found that the present decay width of cluster emitters is clearly enhanced as compared to that in the previous case, which involved the fixed parametrization for the density distributions of daughter nuclei and clusters. Among the whole procedure, the nuclear deformation of clusters is also introduced into the calculations, and the degree of its influence on the final decay half-life is checked to some extent. Moreover, the effect from the bubble density distribution of clusters on the final decay width is carefully discussed by using the central depressed distribution.

  7. The Influence of Hydrothermal Plumes on the Distribution of Anthropogenic Radionuclides Between the Particulate and Dissolved Phases: Results from U.S. Geotraces Equatorial Pacific Zonal Transect GP16

    NASA Astrophysics Data System (ADS)

    Kenna, T. C.; Villa Alfageme, M.; Casacuberta Arola, N.; Masque, P.

    2014-12-01

    Here we present and discuss the results from the analysis of samples from selected stations collected on the US GEOTRACES Equatorial Pacific Zonal Transect (GP16) completed in 2013. The section, between Peru and Tahiti, encompasses a range of processes that influence the supply, removal, and internal cycling of trace metals and offers the opportunity to gain a better understanding of the drivers of the transport and fate of contaminants in the ocean. The capability to analyze water and filtered particulate samples in the quantities available, allows us to determine the partitioning of selected radionuclides among dissolved and particulate forms (Kd) and estimate Pu-particulate fluxes. The overarching objective of our work is to determine the concentrations of several anthropogenic radionuclides, including 239Pu, 240Pu, 237Np, and 137Cs with sufficient resolution to define their basin-wide distributions in the Pacific Ocean. Data collected in the East Pacific Rise hydrothermal plume allows a discussion on the partitioning behavior of plutonium and neptunium.

  8. Lead distributions and risks in New Orleans following Hurricanes Katrina and Rita.

    PubMed

    Abel, Michael T; Cobb, George P; Presley, Steven M; Ray, Gary L; Rainwater, Thomas R; Austin, Galen P; Cox, Stephen B; Anderson, Todd A; Leftwich, Blair D; Kendall, Ronald J; Suedel, Burton C

    2010-07-01

    During the last four years, significant effort has been devoted to understanding the effects that Hurricanes Katrina and Rita had on contaminant distribution and redistribution in New Orleans, Louisiana, USA, and the surrounding Gulf Coast area. Elevated concentrations were found for inorganic contaminants (including As, Fe, Pb, and V), several organic pollutants (polycyclic aromatic hydrocarbons, pesticides, and volatiles) and high concentration of bioaerosols, particularly Aeromonas and Vibrio. Data from different research groups confirm that some contaminant concentrations are elevated, that existing concentrations are similar to historical data, and that contaminants such as Pb and As may pose human health risks. Two data sets have been compiled in this article to serve as the foundation for preliminary risk assessments within greater New Orleans. Research from the present study suggests that children in highly contaminated areas of New Orleans may experience Pb exposure from soil ranging from 1.37 microg/d to 102 microg/d. These data are critical in the evaluation of children's health.

  9. Lead tolerance mechanism in Conyza canadensis: subcellular distribution, ultrastructure, antioxidative defense system, and phytochelatins.

    PubMed

    Li, Ying; Zhou, Chuifan; Huang, Meiying; Luo, Jiewen; Hou, Xiaolong; Wu, Pengfei; Ma, Xiangqing

    2016-03-01

    We used hydroponic experiments to examine the effects of different concentrations of lead (Pb) on the performance of the Pb-tolerable plant Conyza canadensis. In these experiments, most of the Pb was accumulated in the roots; there was very little Pb accumulated in stems and leaves. C. canadensis is able to take up significant amounts of Pb whilst greatly restricting its transportation to specific parts of the aboveground biomass. High Pb concentrations inhibited plant growth, increased membrane permeability, elevated antioxidant enzyme activity in roots, and caused a significant increase in root H2O2 and malondialdehyde content. Analysis of Pb content at the subcellular level showed that most Pb was associated with the cell wall fraction, followed by the nucleus-rich fraction, and with a minority present in the mitochondrial and soluble fractions. Furthermore, transmission electron microscopy and energy dispersive X-ray analysis of root cells revealed that the cell wall and intercellular space in C. canadensis roots are the main locations of Pb accumulation. Additionally, high Pb concentrations adversely affected the cellular structure of C. canadensis roots. The increased enzyme activity suggests that the antioxidant system may play an important role in eliminating or alleviating Pb toxicity in C. canadensis roots. However, the levels of non-protein sulfhydryl compounds, glutathione, and phytochelatin did not significantly change in either the roots or leaves under Pb-contaminated treatments. Our results provide strong evidence that cell walls restrict Pb uptake into the root and act as an important barrier protecting root cells, while demonstrating that antioxidant enzyme levels are correlated with Pb exposure. These findings demonstrate the roles played by these detoxification mechanisms in supporting Pb tolerance in C. canadensis. PMID:26733305

  10. Assessment of Environmental Distribution of Lead in Some Municipalities of South-Eastern Nigeria

    PubMed Central

    Nduka, John Kanayochukwu; Orisakwe, Orish Ebere

    2010-01-01

    Lead (Pb) levels were measured in roadside surface soils, dust particles and rain water samples from the urban cities of Enugu, Awka, Onitsha, Nnewi, Aba, Port Harcourt and Warri in Southern Nigeria in 2007 and 2008. Samples were collected during the dry season, while rain water samples were collected during the early rain (April–June), mid rain (July–August) and late rain seasons (September–October) for the two years. Soil samples were collected from traffic congested roads, dust was collected by tying a plastic basin on a pole 1.5 m above ground level and leaving it for 45 days. Rain samples were collected from three equidistant points. Samples were analyzed by AAS. The highest soil Pb of 120.00 ± 0.00 and 80.36 ± 0.00 mg/kg were reported in Onitsha for 2007 and 2008, respectively. Nnewi showed 33.40 ± 0.01 and 4,238.29 ± 0.00 mg/kg for 2007 and 2008. Aba had 22.56 ± 0.01 and 21.28 ± 0.00 mg/kg for 2007 and 2008. Higher concentrations were recorded for Nnewi and Port Harcourt in 2008 than in 2007. Enugu had more in 2007 while Awka had more in 2008. Dust Pb ranged from 0.13–0.49 mg/kg and 0.15–0.47 mg/kg for 2007 and 2008, respectively. Rain samples had the least Pb concentration, ranging from 0.103 ± 0.000 to 0.163 ± 0.046 mg/L. We may conclude that Nigerians are exposed to environmental Pb. PMID:20644686

  11. Lead tolerance mechanism in Conyza canadensis: subcellular distribution, ultrastructure, antioxidative defense system, and phytochelatins.

    PubMed

    Li, Ying; Zhou, Chuifan; Huang, Meiying; Luo, Jiewen; Hou, Xiaolong; Wu, Pengfei; Ma, Xiangqing

    2016-03-01

    We used hydroponic experiments to examine the effects of different concentrations of lead (Pb) on the performance of the Pb-tolerable plant Conyza canadensis. In these experiments, most of the Pb was accumulated in the roots; there was very little Pb accumulated in stems and leaves. C. canadensis is able to take up significant amounts of Pb whilst greatly restricting its transportation to specific parts of the aboveground biomass. High Pb concentrations inhibited plant growth, increased membrane permeability, elevated antioxidant enzyme activity in roots, and caused a significant increase in root H2O2 and malondialdehyde content. Analysis of Pb content at the subcellular level showed that most Pb was associated with the cell wall fraction, followed by the nucleus-rich fraction, and with a minority present in the mitochondrial and soluble fractions. Furthermore, transmission electron microscopy and energy dispersive X-ray analysis of root cells revealed that the cell wall and intercellular space in C. canadensis roots are the main locations of Pb accumulation. Additionally, high Pb concentrations adversely affected the cellular structure of C. canadensis roots. The increased enzyme activity suggests that the antioxidant system may play an important role in eliminating or alleviating Pb toxicity in C. canadensis roots. However, the levels of non-protein sulfhydryl compounds, glutathione, and phytochelatin did not significantly change in either the roots or leaves under Pb-contaminated treatments. Our results provide strong evidence that cell walls restrict Pb uptake into the root and act as an important barrier protecting root cells, while demonstrating that antioxidant enzyme levels are correlated with Pb exposure. These findings demonstrate the roles played by these detoxification mechanisms in supporting Pb tolerance in C. canadensis.

  12. Assessment of environmental distribution of lead in some municipalities of South-Eastern Nigeria.

    PubMed

    Nduka, John Kanayochukwu; Orisakwe, Orish Ebere

    2010-06-01

    Lead (Pb) levels were measured in roadside surface soils, dust particles and rain water samples from the urban cities of Enugu, Awka, Onitsha, Nnewi, Aba, Port Harcourt and Warri in Southern Nigeria in 2007 and 2008. Samples were collected during the dry season, while rain water samples were collected during the early rain (April-June), mid rain (July-August) and late rain seasons (September-October) for the two years. Soil samples were collected from traffic congested roads, dust was collected by tying a plastic basin on a pole 1.5 m above ground level and leaving it for 45 days. Rain samples were collected from three equidistant points. Samples were analyzed by AAS. The highest soil Pb of 120.00 +/- 0.00 and 80.36 +/- 0.00 mg/kg were reported in Onitsha for 2007 and 2008, respectively. Nnewi showed 33.40 +/- 0.01 and 4,238.29 +/- 0.00 mg/kg for 2007 and 2008. Aba had 22.56 +/- 0.01 and 21.28 +/- 0.00 mg/kg for 2007 and 2008. Higher concentrations were recorded for Nnewi and Port Harcourt in 2008 than in 2007. Enugu had more in 2007 while Awka had more in 2008. Dust Pb ranged from 0.13-0.49 mg/kg and 0.15-0.47 mg/kg for 2007 and 2008, respectively. Rain samples had the least Pb concentration, ranging from 0.103 +/- 0.000 to 0.163 +/- 0.046 mg/L. We may conclude that Nigerians are exposed to environmental Pb. PMID:20644686

  13. Detecting anthropogenic footprints in sea level rise

    NASA Astrophysics Data System (ADS)

    Dangendorf, Sönke; Marcos, Marta; Müller, Alfred; Zorita, Eduardo; Riva, Riccardo; Berk, Kevin; Jensen, Jürgen

    2015-07-01

    While there is scientific consensus that global and local mean sea level (GMSL and LMSL) has risen since the late nineteenth century, the relative contribution of natural and anthropogenic forcing remains unclear. Here we provide a probabilistic upper range of long-term persistent natural GMSL/LMSL variability (P=0.99), which in turn, determines the minimum/maximum anthropogenic contribution since 1900. To account for different spectral characteristics of various contributing processes, we separate LMSL into two components: a slowly varying volumetric component and a more rapidly changing atmospheric component. We find that the persistence of slow natural volumetric changes is underestimated in records where transient atmospheric processes dominate the spectrum. This leads to a local underestimation of possible natural trends of up to ~1 mm per year erroneously enhancing the significance of anthropogenic footprints. The GMSL, however, remains unaffected by such biases. On the basis of a model assessment of the separate components, we conclude that it is virtually certain (P=0.99) that at least 45% of the observed increase in GMSL is of anthropogenic origin.

  14. Detecting anthropogenic footprints in sea level rise

    PubMed Central

    Dangendorf, Sönke; Marcos, Marta; Müller, Alfred; Zorita, Eduardo; Riva, Riccardo; Berk, Kevin; Jensen, Jürgen

    2015-01-01

    While there is scientific consensus that global and local mean sea level (GMSL and LMSL) has risen since the late nineteenth century, the relative contribution of natural and anthropogenic forcing remains unclear. Here we provide a probabilistic upper range of long-term persistent natural GMSL/LMSL variability (P=0.99), which in turn, determines the minimum/maximum anthropogenic contribution since 1900. To account for different spectral characteristics of various contributing processes, we separate LMSL into two components: a slowly varying volumetric component and a more rapidly changing atmospheric component. We find that the persistence of slow natural volumetric changes is underestimated in records where transient atmospheric processes dominate the spectrum. This leads to a local underestimation of possible natural trends of up to ∼1 mm per year erroneously enhancing the significance of anthropogenic footprints. The GMSL, however, remains unaffected by such biases. On the basis of a model assessment of the separate components, we conclude that it is virtually certain (P=0.99) that at least 45% of the observed increase in GMSL is of anthropogenic origin. PMID:26220773

  15. Correlation between the distribution of lignin and pectin and distribution of sorbed metal ions (lead and zinc) on coir (Cocos nucifera L.).

    PubMed

    Conrad, Kathrine

    2008-11-01

    Plant fibres are capacious for sorption of metal ions, and can be used in water cleaning. Knowledge about the sorption will help in selection of the fibre and optimisation of its chemical modification, if any. The aim of this paper is to investigate the connection, if any, between the distribution of lignin and pectin and the loading of Pb and Zn on coir (mesocarp fibres from Cocos nucifera L.). The coir consisted mainly of xylem and a fibre sheath. The lignin was evenly distributed in the cell walls of the fibre sheath, but in the xylem, there was no detectable content in the compound middle lamella, and a smaller content of lignin in the secondary walls than in the walls of the fibre sheath. The only detectable content of pectin in the fibre sheath walls was in the middle lamella, cell corners and extracellular matrix, while in the xylem, the pectin was almost evenly distributed in the wall, with a higher concentration in the middle lamella and cell corners. All cell walls facing the lacuna had a high content of pectin. The metal ions were mainly loaded on the xylem and cell walls facing the lacuna, maybe with an additional trend to be loaded on the large fibres. Lead was distributed on and across the whole secondary wall. Zinc was loaded on the secondary walls, but there was no information about the distribution across the wall. If there is a simple correlation between the loading of metal ions and the distribution of lignin or pectin, these investigations point at no correlation with lignin and a positive correlation with pectin. It has to be stressed that these conclusions are made on limited material and are therefore preliminary in nature.

  16. Simulation of the current distribution in lead-acid batteries to investigate the dynamic charge acceptance in flooded SLI batteries

    NASA Astrophysics Data System (ADS)

    Kowal, Julia; Schulte, Dominik; Sauer, Dirk Uwe; Karden, Eckhard

    Measurements show that the dynamic charge acceptance (DCA) of flooded SLI lead-acid batteries during micro-cycling in conventional and micro-hybrid vehicles is strongly dependent on the short-term history, such as previous charge or discharge, current rate, lowest state of charge in the last 24 h and more. Factors of 10 have been reported. Inhomogeneous current distribution, especially as a result of acid stratification, has been suggested to explain the DCA variability. This hypothesis was investigated by simulation of a two-dimensional macrohomogeneous model. It provides a spatial resolution of three elements in horizontal direction in each electrode and three elements in vertical direction. For an existing set of parameters, different current profiles were analyzed with regard to the current distribution during charging and discharging. In these simulations, a strong impact of the short-term history on current, charge and acid density distribution was found as well as a strong influence of micro-cycles on both charge distribution and acid stratification.

  17. Radial distribution of lead and lead isotopes in stem wood of Norway spruce: A reliable archive of pollution trends in Central Europe

    NASA Astrophysics Data System (ADS)

    Novak, Martin; Mikova, Jitka; Krachler, Michael; Kosler, Jan; Erbanova, Lucie; Prechova, Eva; Jackova, Iva; Fottova, Daniela

    2010-08-01

    Annual growth rings of a common hardwood species, Picea abies L., were investigated as a potential archive of past atmospheric Pb pollution. Wide distribution of trees in terrestrial settings and straightforward chronology are two advantages of this potential geochemical archive, but several processes described in the literature may obscure the trends in past Pb deposition. These confounding factors include, e.g., radial post-depositional mobility of Pb in xylem, and ecosystem acidification leading to higher bioavailability of Pb. One- to five-year annual wood increments were analyzed for Pb concentrations and 206Pb/ 207Pb ratios at Jezeri (JEZ), Uhlirska (UHL) and Na Lizu (LIZ), three sites in the Czech Republic, differing in atmospheric Pb loads. Three to four trees per site were included in the study. Distinct Pb concentration maxima between 1960 and 1990 at the two heavily polluted sites (JEZ and UHL) coincided with historical Pb emissions known from inventories of industrial production. No Pb concentration maxima were found at one site, LIZ, situated in a national park 150 km from major pollution sources. Spruce tree rings from JEZ, located just 5 km from coal-burning power stations, contained a large proportion of coal-derived Pb (a high- 206Pb/ 207Pb ratio of 1.19). A coal-related maximum in 206Pb/ 207Pb in JEZ tree rings was found using two different analytical techniques, laser-ablation multi-collector ICP MS, and single-collector sector-field ICP MS. In a three-isotope graph ( 206Pb/ 207Pb vs. 208Pb/ 207Pb), tree-ring data plotted into the field of ombrotrophic (i.e., rain-fed) peat bogs, suggesting negligible contribution of bedrock-derived Pb in the xylem. We concluded that none of the potential confounding factors played a major role at our sites. Annual growth rings of P. abies in Central Europe faithfully recorded historical changes in atmospheric Pb depositions.

  18. Anthropogenic Osmium in Precipitation

    NASA Astrophysics Data System (ADS)

    Chen, C.; Sedwick, P. N.; Sharma, M.

    2007-12-01

    Here we report the Os isotopic composition for precipitation from Hanover (NH), Soda Springs (CA) and the Ross Sea (Antarctica) as determined by negative thermal ionization mass spectrometry. All samples yielded non- radiogenic Os isotopic compositions. Snow and rain samples from Hanover, NH had Os concentrations of 0.8 - 12.2 fg/g (1 fg/g = 1E-15 g/g) and 187Os/188Os from 0.16 - 0.24. Snowpack from the high Sierra Nevada (Central Sierra Snow Laboratory, Soda Springs, CA) yielded Os concentration and isotopic composition of 3.6 fg/g and 0.21, respectively; Antarctic snow deposited above first year pack ice had [Os] = 0.8 fg/g and 187Os/188Os = 0.42. The isotopic ratios indicate that potential natural sources of Os to the atmosphere, such as continental mineral aerosols (187Os/188Os = 1.26) and seawater (187Os/188Os = 1.05) do not contribute bulk of Os to the precipitation. Instead, the isotopic ratios are identical to the platinum ores from the Merensky Reef in the Bushveld Igneous Complex, South Africa and Noril'sk Ni-Cu sulfide deposit associated with the Siberian Flood Basalts, Russia. These two deposits produce greater than 95 percent of the total Pt, Pd and Rh consumed annually primarily by the automotive industry. We infer that anthropogenic Os contribution dominates the isotopic composition of precipitation. The similar and non-radiogenic Os isotopic compositions observed in precipitation from disparate locations suggest that contamination of the troposphere with anthropogenic Os may be global in scale. We think that processing of ore to extract Pt, Pd, and Rh from PGE ores (PGE: group of six closely related elements Os, Ir, Pt, Pd, Rh, and Ru), which involves smelting and converting at high temperature and in the presence of oxygen, releases the volatile, toxic compound OsO4 into the troposphere, where it is mixed and then scavenged by precipitation, thus explaining both the non-radiogenic isotopic composition and the high and variable Os concentrations of

  19. Anthropogenic carbon dynamics in the changing ocean

    NASA Astrophysics Data System (ADS)

    Tjiputra, J. F.; Assmann, K.; Heinze, C.

    2010-07-01

    The long-term response of CO2 fluxes to climate change at the ocean surface and within the ocean interior is investigated using a coupled climate-carbon cycle model. This study also presents the first attempt to quantify the evolution of lateral transport of anthropogenic carbon under future climate change. Additionally, its impact on regional carbon storage and uptake is also evaluated. For the 1850-2099 period, our climate change simulation predicts oceanic uptake of anthropogenic carbon of about 538±23 Pg C. Another simulation indicates that changes in physical climate and its associated biogeochemical feedbacks result in a release of natural carbon of about 22±30 Pg C. The natural carbon outgassing is attributed to the reduction in solubility and change in wind pattern in the Southern Hemisphere. After the anthropogenic carbon passes through the air-sea interface, it is predominantly transported along the large scale overturning circulation below the surface layer. The spatial variations in the transport patterns in turn influence the evolution of future regional carbon uptake. In the North Atlantic, a slow down in the Atlantic Meridional Overturning Circulation weakens the penetration strength of anthropogenic carbon into the deeper ocean, which leads to a reduced uptake rate in this region. In contrast, more than half of the anthropogenic carbon taken up in the high latitude Southern Ocean region (south of 58° S) is efficiently and continuously exported northward, predominantly into intermediate waters. This transport mechanism allows continuous increase in future carbon uptake in the high latitude Southern Ocean, where the annual uptake strength could reach 39.3±0.9 g C m-2 yr-1, more than twice the global mean of 16.0±0.3 g C m-2 yr-1 by the end of the 21st century. Our study further underlines the key role of the Southern Ocean in controlling long-term future carbon uptake.

  20. Anthropogenic carbon dynamics in the changing ocean

    NASA Astrophysics Data System (ADS)

    Tjiputra, J. F.; Assmann, K.; Heinze, C.

    2010-03-01

    Long-term response of CO2 fluxes to climate change at the ocean surface and the ocean interior are investigated using a coupled climate-carbon cycle model. This study also presents the first attempt in quantifying the evolution of lateral transport of anthropogenic carbon under future climate change. Additionally, its impact on regional carbon storage and uptake are also evaluated. For the 1850-2100 period, our climate change simulation predicts oceanic uptake of anthropogenic carbon of about 538 Pg C. Another simulation indicates that changes in physical climate alone results in a release of natural carbon of about 22 Pg C. The natural carbon outgassing is attributed to the reduction in solubility and change in wind pattern in the Southern Hemisphere. After the anthropogenic carbon passes through the air-sea interface, it is predominantly transported along the large scale overturning circulation below the surface layer. The spatial variations in the transport patterns in turn influence the evolution of future regional carbon uptake. In the North Atlantic, a slow down in Atlantic Meridional Overturnning Circulation weakens the penetration strength of anthropogenic carbon into the deeper ocean, which leads to the reduced uptake rate in this region. In contrast, more than half of the anthropogenic carbon taken up in the high latitude Southern Ocean region (south of 58° S) are efficiently and continuously exported northward, predominantly into intermediate waters. This peculiar transport mechanism allow continuous increase in future carbon uptake in the high latitude Southern Ocean, where the annual uptake strength could reach 3.5 g C m-2 yr-1, nearly triple the global mean of 1.3 g C m-2 yr-1 by the end of the 21st century. Our study further underlines the key role of the Southern Ocean in controlling long-term future carbon uptake.

  1. Unpolarized transverse momentum dependent parton distribution and fragmentation functions at next-to-next-to-leading order

    NASA Astrophysics Data System (ADS)

    Echevarria, Miguel G.; Scimemi, Ignazio; Vladimirov, Alexey

    2016-09-01

    The transverse momentum dependent parton distribution/fragmentation functions (TMDs) are essential in the factorization of a number of processes like Drell-Yan scattering, vector boson production, semi-inclusive deep inelastic scattering, etc. We provide a comprehensive study of unpolarized TMDs at next-to-next-to-leading order, which includes an explicit calculation of these TMDs and an extraction of their matching coefficients onto their integrated analogues, for all flavor combinations. The obtained matching coefficients are important for any kind of phenomenology involving TMDs. In the present study each individual TMD is calculated without any reference to a specific process. We recover the known results for parton distribution functions and provide new results for the fragmentation functions. The results for the gluon transverse momentum dependent fragmentation functions are presented for the first time at one and two loops. We also discuss the structure of singularities of TMD operators and TMD matrix elements, crossing relations between TMD parton distribution functions and TMD fragmentation functions, and renormalization group equations. In addition, we consider the behavior of the matching coefficients at threshold and make a conjecture on their structure to all orders in perturbation theory.

  2. Predicting Anthropogenic Noise Contributions to US Waters.

    PubMed

    Gedamke, Jason; Ferguson, Megan; Harrison, Jolie; Hatch, Leila; Henderson, Laurel; Porter, Michael B; Southall, Brandon L; Van Parijs, Sofie

    2016-01-01

    To increase understanding of the potential effects of chronic underwater noise in US waters, the National Oceanic and Atmospheric Administration (NOAA) organized two working groups in 2011, collectively called "CetSound," to develop tools to map the density and distribution of cetaceans (CetMap) and predict the contribution of human activities to underwater noise (SoundMap). The SoundMap effort utilized data on density, distribution, acoustic signatures of dominant noise sources, and environmental descriptors to map estimated temporal, spatial, and spectral contributions to background noise. These predicted soundscapes are an initial step toward assessing chronic anthropogenic noise impacts on the ocean's varied acoustic habitats and the animals utilizing them.

  3. Anthropogenic Aerosols and the Dust Bowl

    NASA Astrophysics Data System (ADS)

    Cazavilan, E. J.; Leibensperger, E. M.

    2014-12-01

    We use a general circulation model (GISS GCM ModelE) to study the impact of anthropogenic aerosols on the 1930s Dust Bowl. The Dust Bowl was primarily forced by anomalous sea surface temperatures, but may have been partially shaped by the large amounts of black carbon emitted at that time. A simulation using observed 1932-1938 sea surface temperature and sea ice distributions reveal drier and warmer conditions in the central U.S. Adding the influence of 1930s anthropogenic aerosols exacerbates the drying and warm conditions (0.2 °C increase over mid-west continental US, and a decrease of -0.1 mm/day of precipitation). We find that these changes are concurrent with a weakening and shift of the Bermuda High.

  4. Detection of anthropogenic dust using CALIPSO lidar measurements

    NASA Astrophysics Data System (ADS)

    Huang, J. P.; Liu, J. J.; Chen, B.; Nasiri, S. L.

    2015-10-01

    Anthropogenic dusts are those produced by human activities on disturbed soils, which are mainly cropland, pastureland, and urbanized regions, and are a subset of the total dust load which includes natural sources from desert regions. Our knowledge of anthropogenic dusts is still very limited due to a lack of data. To understand the contribution of anthropogenic dust to the total global dust load, it is important to identify it apart from total dust. In this study, a new technique for distinguishing anthropogenic dust from natural dust is proposed by using Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) dust and planetary boundary layer (PBL) height retrievals along with a land use data set. Using this technique, the global distribution of dust is analyzed and the relative contribution of anthropogenic and natural dust sources to regional and global emissions are estimated. Results reveal that local anthropogenic dust aerosol due to human activity, such as agriculture, industrial activity, transportation, and overgrazing, accounts for about 25 % of the global continental dust load. Of these anthropogenic dust aerosols, more than 53 % come from semi-arid and semi-wet regions. Annual mean anthropogenic dust column burden (DCB) values range from 0.42 g m-2, with a maximum in India, to 0.12 g m-2, with a minimum in North America. A better understanding of anthropogenic dust emission will enable us to focus on human activities in these critical regions and with such knowledge we will be more able to improve global dust models and to explore the effects of anthropogenic emission on radiative forcing, climate change, and air quality in the future.

  5. A novel in situ method for sampling urban soil dust: particle size distribution, trace metal concentrations, and stable lead isotopes.

    PubMed

    Bi, Xiangyang; Liang, Siyuan; Li, Xiangdong

    2013-06-01

    In this study, a novel in situ sampling method was utilized to investigate the concentrations of trace metals and Pb isotope compositions among different particle size fractions in soil dust, bulk surface soil, and corresponding road dust samples collected within an urban environment. The aim of the current study was to evaluate the feasibility of using soil dust samples to determine trace metal contamination and potential risks in urban areas in comparison with related bulk surface soil and road dust. The results of total metal loadings and Pb isotope ratios revealed that soil dust is more sensitive than bulk surface soil to anthropogenic contamination in urban areas. The new in situ method is effective at collecting different particle size fractions of soil dust from the surface of urban soils, and that soil dust is a critical indicator of anthropogenic contamination and potential human exposure in urban settings.

  6. Effects of 1,25-dihydroxicolecalciferol and dietary calcium-phosphate on distribution of lead to tissues during growth

    SciTech Connect

    Cortina-Ramirez, G.E.; Cerbon-Solorzano, J.; Calderon-Salinas, J.V. . E-mail: jcalder@cinvestav.mx

    2006-01-15

    The susceptibility to the toxic effects of lead (Pb) is mainly mediated by age and nutritional and hormonal status, and children are among the most vulnerable to them. During growth, an increase in calcium, phosphate and vitamin D in diet is recommended to enhance calcium and phosphate intestinal absorption and bone deposit. Calcium and phosphate reduce lead intestinal absorption, and 1,25-dihydroxicolecalciferol (1,25(OH){sub 2}D{sub 3}) (active metabolite of vitamin D) increases both lead and calcium intestinal absorption. However, the effects of 1,25(OH){sub 2}D{sub 3} on lead bone deposit and redistribution to soft tissues are not well known. In this study, we examined the effects of calcium-phosphate diet supplementation and the administration of 1,25(OH){sub 2}D{sub 3} on Pb distribution to soft tissue and bone in growing rats exposed to Pb. Rats (21 days old) were exposed for 28 days to 100 ppm of Pb solution in drinking water. Calcium and phosphate in diet were increased from 1 to 2.5% and from 0.65 to 1.8%, respectively, and 1,25(OH){sub 2}D{sub 3} was administrated by intraperitoneal injection of 7.2 ng/kg every 7 days. Between 21 and 49 days, the body weight increased about 5 times. The results showed that high calcium-phosphate diet led to lower Pb concentration in blood and in bone, but Pb liver and kidney concentrations increased, which indicates that absorption and bone deposit redistribution of Pb decreased. On the other hand, no effect of this diet rich in calcium-phosphate in Pb concentration was observed in brain. Blood and bone Pb concentrations increased even more when the high calcium-phosphate diet included 1,25(OH){sub 2}D{sub 3}. In the rats treated only with 1,25(OH){sub 2}D{sub 3}, blood and bone Pb concentrations were lower. Higher concentrations of lead in the soft organs were observed also in rats treated under a high calcium-phosphate diet plus 1,25(OH){sub 2}D{sub 3} administration. The above mentioned results suggested that 1,25(OH

  7. Effects of 1,25-dihydroxicolecalciferol and dietary calcium-phosphate on distribution of lead to tissues during growth.

    PubMed

    Cortina-Ramírez, G E; Cerbón-Solorzano, J; Calderón-Salinas, J V

    2006-01-01

    The susceptibility to the toxic effects of lead (Pb) is mainly mediated by age and nutritional and hormonal status, and children are among the most vulnerable to them. During growth, an increase in calcium, phosphate and vitamin D in diet is recommended to enhance calcium and phosphate intestinal absorption and bone deposit. Calcium and phosphate reduce lead intestinal absorption, and 1,25-dihydroxicolecalciferol (1,25(OH)2D3) (active metabolite of vitamin D) increases both lead and calcium intestinal absorption. However, the effects of 1,25(OH)2D3 on lead bone deposit and redistribution to soft tissues are not well known. In this study, we examined the effects of calcium-phosphate diet supplementation and the administration of 1,25(OH)2D3 on Pb distribution to soft tissue and bone in growing rats exposed to Pb. Rats (21 days old) were exposed for 28 days to 100 ppm of Pb solution in drinking water. Calcium and phosphate in diet were increased from 1 to 2.5% and from 0.65 to 1.8%, respectively, and 1,25(OH)2D3 was administrated by intraperitoneal injection of 7.2 ng/kg every 7 days. Between 21 and 49 days, the body weight increased about 5 times. The results showed that high calcium-phosphate diet led to lower Pb concentration in blood and in bone, but Pb liver and kidney concentrations increased, which indicates that absorption and bone deposit redistribution of Pb decreased. On the other hand, no effect of this diet rich in calcium-phosphate in Pb concentration was observed in brain. Blood and bone Pb concentrations increased even more when the high calcium-phosphate diet included 1,25(OH)2D3. In the rats treated only with 1,25(OH)2D3, blood and bone Pb concentrations were lower. Higher concentrations of lead in the soft organs were observed also in rats treated under a high calcium-phosphate diet plus 1,25(OH)2D3 administration. The above mentioned results suggested that 1,25(OH)2D3 induces an increased absorption and redistribution of Pb, and therefore, it may

  8. Constraints on the leading-twist pion distribution amplitude from a QCD light-cone sum rule with chiral current

    NASA Astrophysics Data System (ADS)

    Wu, Xing-Gang

    2008-10-01

    We present an improved analysis of the constraints on the first two Gegenbauer moments, a {2/ π } and a {4/ π }, of the pion’s leading-twist distribution amplitude from a QCD light-cone sum rule analysis of the B→ π weak transition form factor f +( q 2). A proper chiral current is adopted in QCD light-cone sum rules so as to eliminate the most uncertain twist-3 contributions to f +( q 2), and then we concentrate our attention on the properties of the leading-twist pionic DA. A nearly model-independent f +( q 2), based on the spectrum of B→ π l ν decays from BaBar, together with uncertainties, is adopted as the standard shape for f +( q 2) for our discussion. From a minimum χ 2-fit and by taking the theoretical uncertainties into account, we obtain a {2/ π }(1 GeV)=0.17{-0.17/+0.15} and a {4/ π }(1 GeV)=-0.06{-0.22/+0.20} at the 1 σ confidence level for m {b/*}∈[4.7,4,8] GeV.

  9. Diode-Pumped Organo-Lead Halide Perovskite Lasing in a Metal-Clad Distributed Feedback Resonator.

    PubMed

    Jia, Yufei; Kerner, Ross A; Grede, Alex J; Brigeman, Alyssa N; Rand, Barry P; Giebink, Noel C

    2016-07-13

    Organic-inorganic lead halide perovskite semiconductors have recently reignited the prospect of a tunable, solution-processed diode laser, which has the potential to impact a wide range of optoelectronic applications. Here, we demonstrate a metal-clad, second-order distributed feedback methylammonium lead iodide perovskite laser that marks a significant step toward this goal. Optically pumping this device with an InGaN diode laser at low temperature, we achieve lasing above a threshold pump intensity of 5 kW/cm(2) for durations up to ∼25 ns at repetition rates exceeding 2 MHz. We show that the lasing duration is not limited by thermal runaway and propose instead that lasing ceases under continuous pumping due to a photoinduced structural change in the perovskite that reduces the gain on a submicrosecond time scale. Our results indicate that the architecture demonstrated here could provide the foundation for electrically pumped lasing with a threshold current density Jth < 5 kA/cm(2) under sub-20 ns pulsed drive. PMID:27331618

  10. Diode-Pumped Organo-Lead Halide Perovskite Lasing in a Metal-Clad Distributed Feedback Resonator.

    PubMed

    Jia, Yufei; Kerner, Ross A; Grede, Alex J; Brigeman, Alyssa N; Rand, Barry P; Giebink, Noel C

    2016-07-13

    Organic-inorganic lead halide perovskite semiconductors have recently reignited the prospect of a tunable, solution-processed diode laser, which has the potential to impact a wide range of optoelectronic applications. Here, we demonstrate a metal-clad, second-order distributed feedback methylammonium lead iodide perovskite laser that marks a significant step toward this goal. Optically pumping this device with an InGaN diode laser at low temperature, we achieve lasing above a threshold pump intensity of 5 kW/cm(2) for durations up to ∼25 ns at repetition rates exceeding 2 MHz. We show that the lasing duration is not limited by thermal runaway and propose instead that lasing ceases under continuous pumping due to a photoinduced structural change in the perovskite that reduces the gain on a submicrosecond time scale. Our results indicate that the architecture demonstrated here could provide the foundation for electrically pumped lasing with a threshold current density Jth < 5 kA/cm(2) under sub-20 ns pulsed drive.

  11. Bringing home the trash: do colony-based differences in foraging distribution lead to increased plastic ingestion in Laysan albatrosses?

    PubMed

    Young, Lindsay C; Vanderlip, Cynthia; Duffy, David C; Afanasyev, Vsevolod; Shaffer, Scott A

    2009-01-01

    When searching for prey, animals should maximize energetic gain, while minimizing energy expenditure by altering their movements relative to prey availability. However, with increasing amounts of marine debris, what once may have been 'optimal' foraging strategies for top marine predators, are leading to sub-optimal diets comprised in large part of plastic. Indeed, the highly vagile Laysan albatross (Phoebastria immutabilis) which forages throughout the North Pacific, are well known for their tendency to ingest plastic. Here we examine whether Laysan albatrosses nesting on Kure Atoll and Oahu Island, 2,150 km apart, experience different levels of plastic ingestion. Twenty two geolocators were deployed on breeding adults for up to two years. Regurgitated boluses of undigestable material were also collected from chicks at each site to compare the amount of plastic vs. natural foods. Chicks from Kure Atoll were fed almost ten times the amount of plastic compared to chicks from Oahu despite boluses from both colonies having similar amounts of natural food. Tracking data indicated that adults from either colony did not have core overlapping distributions during the early half of the breeding period and that adults from Kure had a greater overlap with the putative range of the Western Garbage Patch corroborating our observation of higher plastic loads at this colony. At-sea distributions also varied throughout the year suggesting that Laysan albatrosses either adjusted their foraging behavior according to constraints on time away from the nest or to variation in resources. However, in the non-breeding season, distributional overlap was greater indicating that the energy required to reach the foraging grounds was less important than the total energy available. These results demonstrate how a marine predator that is not dispersal limited alters its foraging strategy throughout the reproductive cycle to maximize energetic gain and how this has led to differences in plastic

  12. Bringing Home the Trash: Do Colony-Based Differences in Foraging Distribution Lead to Increased Plastic Ingestion in Laysan Albatrosses?

    PubMed Central

    Young, Lindsay C.; Vanderlip, Cynthia; Duffy, David C.; Afanasyev, Vsevolod; Shaffer, Scott A.

    2009-01-01

    When searching for prey, animals should maximize energetic gain, while minimizing energy expenditure by altering their movements relative to prey availability. However, with increasing amounts of marine debris, what once may have been ‘optimal’ foraging strategies for top marine predators, are leading to sub-optimal diets comprised in large part of plastic. Indeed, the highly vagile Laysan albatross (Phoebastria immutabilis) which forages throughout the North Pacific, are well known for their tendency to ingest plastic. Here we examine whether Laysan albatrosses nesting on Kure Atoll and Oahu Island, 2,150 km apart, experience different levels of plastic ingestion. Twenty two geolocators were deployed on breeding adults for up to two years. Regurgitated boluses of undigestable material were also collected from chicks at each site to compare the amount of plastic vs. natural foods. Chicks from Kure Atoll were fed almost ten times the amount of plastic compared to chicks from Oahu despite boluses from both colonies having similar amounts of natural food. Tracking data indicated that adults from either colony did not have core overlapping distributions during the early half of the breeding period and that adults from Kure had a greater overlap with the putative range of the Western Garbage Patch corroborating our observation of higher plastic loads at this colony. At-sea distributions also varied throughout the year suggesting that Laysan albatrosses either adjusted their foraging behavior according to constraints on time away from the nest or to variation in resources. However, in the non-breeding season, distributional overlap was greater indicating that the energy required to reach the foraging grounds was less important than the total energy available. These results demonstrate how a marine predator that is not dispersal limited alters its foraging strategy throughout the reproductive cycle to maximize energetic gain and how this has led to differences in

  13. Identification And Distribution Of Vanadinite (Pb5(V5+O4)3Cl) In Lead Pipe Corrosion By-Products

    EPA Science Inventory

    This study presents the first detailed look at vanadium (V) speciation in drinking water pipe corrosion scales. A pool of 34 scale layers from 15 lead or lead-lined pipes representing eight different municipal drinking water distribution systems in the Northeastern and Midwester...

  14. Mildly compromised tetrahydrobiopterin cofactor biosynthesis due to Pts variants leads to unusual body fat distribution and abdominal obesity in mice.

    PubMed

    Korner, Germaine; Scherer, Tanja; Adamsen, Dea; Rebuffat, Alexander; Crabtree, Mark; Rassi, Anahita; Scavelli, Rossana; Homma, Daigo; Ledermann, Birgit; Konrad, Daniel; Ichinose, Hiroshi; Wolfrum, Christian; Horsch, Marion; Rathkolb, Birgit; Klingenspor, Martin; Beckers, Johannes; Wolf, Eckhard; Gailus-Durner, Valérie; Fuchs, Helmut; Hrabě de Angelis, Martin; Blau, Nenad; Rozman, Jan; Thöny, Beat

    2016-03-01

    Tetrahydrobiopterin (BH4) is an essential cofactor for the aromatic amino acid hydroxylases, alkylglycerol monooxygenase, and nitric oxide synthases (NOS). Inborn errors of BH4 metabolism lead to severe insufficiency of brain monoamine neurotransmitters while augmentation of BH4 by supplementation or stimulation of its biosynthesis is thought to ameliorate endothelial NOS (eNOS) dysfunction, to protect from (cardio-) vascular disease and/or prevent obesity and development of the metabolic syndrome. We have previously reported that homozygous knock-out mice for the 6-pyruvolytetrahydropterin synthase (PTPS; Pts-ko/ko) mice with no BH4 biosynthesis die after birth. Here we generated a Pts-knock-in (Pts-ki) allele expressing the murine PTPS-p.Arg15Cys with low residual activity (15% of wild-type in vitro) and investigated homozygous (Pts-ki/ki) and compound heterozygous (Pts-ki/ko) mutants. All mice showed normal viability and depending on the severity of the Pts alleles exhibited up to 90% reduction of PTPS activity concomitant with neopterin elevation and mild reduction of total biopterin while blood L-phenylalanine and brain monoamine neurotransmitters were unaffected. Yet, adult mutant mice with compromised PTPS activity (i.e., Pts-ki/ko, Pts-ki/ki or Pts-ko/wt) had increased body weight and elevated intra-abdominal fat. Comprehensive phenotyping of Pts-ki/ki mice revealed alterations in energy metabolism with proportionally higher fat content but lower lean mass, and increased blood glucose and cholesterol. Transcriptome analysis indicated changes in glucose and lipid metabolism. Furthermore, differentially expressed genes associated with obesity, weight loss, hepatic steatosis, and insulin sensitivity were consistent with the observed phenotypic alterations. We conclude that reduced PTPS activity concomitant with mildly compromised BH4-biosynthesis leads to abnormal body fat distribution and abdominal obesity at least in mice. This study associates a novel

  15. Lead in soil and agricultural products in the Huainan Coal Mining Area, Anhui, China: levels, distribution, and health implications.

    PubMed

    Fang, Ting; Liu, Guijian; Zhou, Chuncai; Lu, Lanlan

    2015-03-01

    Heavy metal accumulation in agricultural soil is of great concern, as heavy metals can be finally transferred to the human body through the food chain. A field survey was conducted to investigate the lead (Pb) levels and distribution in soil, agricultural products (wheat, paddy, and soybean), and fish, in the Huainan Coal Mining Area (HCMA), Anhui Province, China, to provide reference information to local inhabitants. The daily intake and target hazard quotients of Pb through food consumption were assessed. Results showed that the mean Pb concentration in soil was higher than the Huainan soil background Pb value but lower than the maximum allowance Pb concentration for agricultural soil (GB 15618-2008). The elevated Pb in soil, especially in rainy months (June to August in Huainan), might be related to Pb leaching from ambient coal gangue piles. Excessive Pb concentration was found in the grains of food crops, which would pose a potential health risk to local inhabitants. Therein, wheat showed higher Pb bioaccumulation ability than other crops. With regard to the Pb levels in muscles, fishes were considered to be safe for consumption. The calculations on daily intake and tolerable hazard quotient of Pb suggest that the potential health hazard posed by Pb is currently insignificant for the inhabitants in the HCMA.

  16. Lead in soil and agricultural products in the Huainan Coal Mining Area, Anhui, China: levels, distribution, and health implications.

    PubMed

    Fang, Ting; Liu, Guijian; Zhou, Chuncai; Lu, Lanlan

    2015-03-01

    Heavy metal accumulation in agricultural soil is of great concern, as heavy metals can be finally transferred to the human body through the food chain. A field survey was conducted to investigate the lead (Pb) levels and distribution in soil, agricultural products (wheat, paddy, and soybean), and fish, in the Huainan Coal Mining Area (HCMA), Anhui Province, China, to provide reference information to local inhabitants. The daily intake and target hazard quotients of Pb through food consumption were assessed. Results showed that the mean Pb concentration in soil was higher than the Huainan soil background Pb value but lower than the maximum allowance Pb concentration for agricultural soil (GB 15618-2008). The elevated Pb in soil, especially in rainy months (June to August in Huainan), might be related to Pb leaching from ambient coal gangue piles. Excessive Pb concentration was found in the grains of food crops, which would pose a potential health risk to local inhabitants. Therein, wheat showed higher Pb bioaccumulation ability than other crops. With regard to the Pb levels in muscles, fishes were considered to be safe for consumption. The calculations on daily intake and tolerable hazard quotient of Pb suggest that the potential health hazard posed by Pb is currently insignificant for the inhabitants in the HCMA. PMID:25724617

  17. Lead in ancient Rome’s city waters

    PubMed Central

    Delile, Hugo; Blichert-Toft, Janne; Goiran, Jean-Philippe; Keay, Simon; Albarède, Francis

    2014-01-01

    It is now universally accepted that utilization of lead for domestic purposes and water distribution presents a major health hazard. The ancient Roman world was unaware of these risks. How far the gigantic network of lead pipes used in ancient Rome compromised public health in the city is unknown. Lead isotopes in sediments from the harbor of Imperial Rome register the presence of a strong anthropogenic component during the beginning of the Common Era and the Early Middle Ages. They demonstrate that the lead pipes of the water distribution system increased Pb contents in drinking water of the capital city by up to two orders of magnitude over the natural background. The Pb isotope record shows that the discontinuities in the pollution of the Tiber by lead are intimately entwined with the major issues affecting Late Antique Rome and its water distribution system. PMID:24753588

  18. Anthropogenic Aerosols and the Evolution of U.S. Droughts

    NASA Astrophysics Data System (ADS)

    Leibensperger, E. M.; Cazavilan, E. J.

    2014-12-01

    Anthropogenic aerosols interact with solar radiation to influence regional to global climate. Trends in aerosol concentrations have impacted the evolution of surface air temperatures and the hydrological cycle over the last 150 years, but the magnitude of influence and any role in shaping extreme events remains uncertain. We use a general circulation model (GISS GCM ModelE) to study the impact of anthropogenic aerosols on the formation of two potential U.S. droughts. Two periods are analyzed, the 1930s Dust Bowl and the 1970s "missed drought". Each period realized ocean conditions ripe for the formation of central U.S. drought, but experienced differing composition and amounts of anthropogenic aerosol forcing. Simulations forced solely by observed sea surface temperature and sea ice distributions reveal drier and warmer conditions in the central U.S. (annual decreases of up to 0.5 mm/day and warming of 0.5°C). We find that anthropogenic aerosols of the 1930s, containing a significant warming component from U.S. black carbon, exacerbated the warm conditions (0.2°C) and provided slightly drier conditions. In contrast, anthropogenic aerosols of the 1970s, containing a large cooling component from U.S. sulfate, reduced annual precipitation deficits and lowered temperatures by up to 0.4°C. Our results showcase the importance of anthropogenic aerosol forcing in the evolution of U.S. droughts.

  19. Ring distributions leading to species formation: a global topographic analysis of geographic barriers associated with ring species

    PubMed Central

    2012-01-01

    Background In the mid 20th century, Ernst Mayr and Theodosius Dobzhansky championed the significance of circular overlaps or ring species as the perfect demonstration of speciation, yet in the over 50 years since, only a handful of such taxa are known. We developed a topographic model to evaluate whether the geographic barriers that favor processes leading to ring species are common or rare, and to predict where other candidate ring barriers might be found. Results Of the 952,147 geographic barriers identified on the planet, only about 1% are topographically similar to barriers associated with known ring taxa, with most of the likely candidates occurring in under-studied parts of the world (for example, marine environments, tropical latitudes). Predicted barriers separate into two distinct categories: (i) single cohesive barriers (< 50,000 km2), associated with taxa that differentiate at smaller spatial scales (salamander: Ensatina eschscholtzii; tree: Acacia karroo); and (ii) composite barriers - formed by groups of barriers (each 184,000 to 1.7 million km2) in close geographic proximity (totaling 1.9 to 2.3 million km2) - associated with taxa that differentiate at larger spatial scales (birds: Phylloscopus trochiloides and Larus (sp. argentatus and fuscus)). When evaluated globally, we find a large number of cohesive barriers that are topographically similar to those associated with known ring taxa. Yet, compared to cohesive barriers, an order of magnitude fewer composite barriers are similar to those that favor ring divergence in species with higher dispersal. Conclusions While these findings confirm that the topographic conditions that favor evolutionary processes leading to ring speciation are, in fact, rare, they also suggest that many understudied natural systems could provide valuable demonstrations of continuous divergence towards the formation of new species. Distinct advantages of the model are that it (i) requires no a priori information on the relative

  20. Improvements and Validation of Sulfur Dioxide Retrievals from Aura/OMI Observations of Anthropogenic Pollution

    NASA Astrophysics Data System (ADS)

    Yang, K.; Krotkov, N. A.; He, H.; Dickerson, R. R.; Li, C.

    2011-12-01

    Both natural and anthropogenic sources can release the trace gas, sulfur dioxide (SO2), into the atmosphere, in which it is usually oxidized to form sulfate aerosols, affecting the environment and climate. The largest contributions to the total annual sulfur budget are anthropogenic emissions from combustions of fossil fuels and smelting of metal ores. While these sources emit SO2 into the atmospheric planetary boundary layer (PBL), leading to air quality degradation near the source regions, the pollutants are sometimes lifted into the free troposphere and subsequently transported over long distances, affecting remote regions. It is therefore important to monitor the spatial and temporal distribution of SO2 over the globe. This can be accomplished with satellite UV remote sensing, as exemplified by the SO2 data derived from the global daily observations made by the Dutch-Finnish Ozone Monitoring Instrument (OMI) on board NASA's Aura spacecraft launched in July 2004. In this presentation, we describe the recent progress in developing an advanced algorithm to improve detection and quantification of anthropogenic SO2, and compare the new retrievals with the operational OMI SO2 products to show significant reduction in noise and bias. We also present validation results obtained by the comparisons with co-located in-situ aircraft measurements in China in 2005 - 2008 and during DISCOVER-AQ field experiment in Maryland in July 2011, to illustrate improved accuracy achieved with the advanced algorithm.

  1. Predicting Anthropogenic Noise Contributions to US Waters.

    PubMed

    Gedamke, Jason; Ferguson, Megan; Harrison, Jolie; Hatch, Leila; Henderson, Laurel; Porter, Michael B; Southall, Brandon L; Van Parijs, Sofie

    2016-01-01

    To increase understanding of the potential effects of chronic underwater noise in US waters, the National Oceanic and Atmospheric Administration (NOAA) organized two working groups in 2011, collectively called "CetSound," to develop tools to map the density and distribution of cetaceans (CetMap) and predict the contribution of human activities to underwater noise (SoundMap). The SoundMap effort utilized data on density, distribution, acoustic signatures of dominant noise sources, and environmental descriptors to map estimated temporal, spatial, and spectral contributions to background noise. These predicted soundscapes are an initial step toward assessing chronic anthropogenic noise impacts on the ocean's varied acoustic habitats and the animals utilizing them. PMID:26610977

  2. Spatial Distribution of Lead Isotope Ratios and Inorganic Element Concentrations in Epiphytic Lichens from the Athabasca Oil Sands Region

    NASA Astrophysics Data System (ADS)

    Graney, J. R.; Landis, M. S.; Puckett, K.; Edgerton, E.; Krupa, S.; Percy, K.

    2013-12-01

    Coupled studies of inorganic element concentrations and lead (Pb) isotope ratios have been conducted on Hypogymnia physodes samples collected in the Athabasca Oil Sands Region (AOSR) in Alberta, Canada in 2002, 2008, and 2011. To investigate the spatial extent of air emissions, the lichens were collected from sites as far as 160 km from the mining and processing operations. 30 milligram sub-samples of the lichens were microwave digested, and the extracts were analyzed using DRC-ICPMS to determine elemental concentrations, and sector field ICPMS to measure Pb isotope ratios. Concentrations of elements in the lichens were found to reflect proximity to mining and oil processing sites as well as topography, ecosystem differences, and the metabolic biogeochemistry of the lichens. An exponential decrease in concentration of metals associated with fugitive dust (aluminum and others) versus distance from the mining sites, suggests elevated coarse particle emissions associated with mining operations. Near source concentrations of metals with an oil signature (vanadium and others) are less enhanced and more homogeneous than the metals in the fugitive dust, reflecting emission and deposition of smaller diameter particles at greater distances from oil processing sources. The mining and oil processing signatures are superimposed over elemental concentrations that reflect the nutrient needs of the lichens. These findings are being confirmed through ongoing studies using dichot samplers to collect coarse and fine particulate aerosol samples. The lichen samples collected beyond 50 km from the mining and processing sites cluster into a Pb isotope grouping with a 207Pb / 206Pb ratio of 0.8650 and a 208Pb / 206Pb ratio near 2.095. This grouping likely reflects the regional background Pb isotope ratio signature. 207Pb / 206Pb and 208Pb / 206Pb ratios decrease as one nears the mining and processing operations. This indicates that other Pb source(s), (e.g. Pb in the bitumen from the oil

  3. Influences of phosphate nutritional level on the phytoavailability and speciation distribution of cadmium and lead in soil.

    PubMed

    Chen, Su; Sun, Tie-heng; Sun, Li-na; Zhou, Qi-xing; Chao, Lei

    2006-01-01

    A pot experiment was conducted to examine the influence of phosphate levels on the phytoavailability and speciation distribution of cadmium (Cd), lead (Pb) in soil. Spring wheat (Triticum aestivum L.) was selected as the tested plant. There were 5 phosphate fertilizer(Ca(H2PO4)2) levels including 0, 50, 100, 200, and 400 mg P2O5/kg soil, marked by PO, P1, P2, P3, and P4, respectively. CdCl2 x 2.5H2O and Pb(NO3)2 were added to soil as the following levels: Cd + Pb = 25+0, 0+1000, and 25+1000 mg/kg, marked by T1, T2, and T3, respectively. The results showed that the P fertilizer promoted the dry weight of wheat in all treatments and alleviated the contamination induced by Cd and Pb. With increasing levels of the additional P fertilizer, Cd concentration in different parts (root, haulm, chaffand grain) of wheat decreased at the P1 level at first and then increased. The soluble plus exchangeable (SE) fraction of Cd in soil decreased at the P1 level and then increased from P2 to P4 levels. The moderate P fertilizer reduced the phytoavailability of Cd. The application of P could obviously restrain the uptake of Pb by wheat and there were significantly negative correlations between the levels of P and the uptake of Pb. Phosphorus supply resulted in a decrease in the SE fraction of Pb and there was a significantly negative correlation between the levels of P and the SE fraction of Pb in soil. All the levels of the P fertilizer in this experiment could reduce the phytoavailability of Pb. Thus, it is feasible to apply the P fertilizer (Ca(H2PO4)2) to Pb contaminated soils. However, the levels of P application should be restricted in case that redundant P may increase the phytoavailability of Cd.

  4. Past and Future of the Anthropogenic Biosphere

    NASA Astrophysics Data System (ADS)

    Ellis, E. C.

    2010-12-01

    Human populations and their use of land have now transformed most of the terrestrial biosphere into anthropogenic biomes (anthromes). As anthromes have emerged as the dominant global forms of ecological pattern and process, human interactions with terrestrial ecosystems have become a key earth system process, determining the structure and functioning of the biosphere. This presentation explores Ester Boserup’s land use intensification theories as models for understanding the emergence and dynamics of anthromes and their ecological processes, including their biogeochemistry and community structure, from the mostly wild biosphere of the Holocene to the primarily anthropogenic biosphere of the present and future. Existing global models and data for human population growth and land use over the Holocene differ in their portrayal of the global transition to a mostly anthropogenic biosphere. Yet there is little doubt that human populations have continued to grow over the long term and that anthromes have been increasingly important global ecological systems for millennia. This is conclusive evidence that human interactions with ecosystems can be sustained over the long-term, albeit under conditions that may no longer be realizable by either Earth or human systems. The classic Malthusian paradigm, in which human population growth outstrips natural resources leading to population collapse is unsupported by historical observations at global scale. Boserupian intensification is the better model, providing a robust theoretical foundation in which socio-ecological systems evolve as human populations increase, towards increasingly efficient use of limiting natural resources and enhanced production of anthropogenic ecological services such as food. This is not a story of technical advance, but rather of the forced adoption of ever more energy-intensive technical solutions in support of ever increasing population demands. And it does explain historical changes in the biosphere

  5. Estimating animal mortality from anthropogenic hazards

    EPA Science Inventory

    Carcass searches are a common method for studying the risk of anthropogenic hazards to wildlife, including non-target poisoning and collisions with anthropogenic structures. Typically, numbers of carcasses found must be corrected for scavenging rates and imperfect detection. Para...

  6. Leading-twist pion and kaon distribution amplitudes in the gauge-invariant nonlocal chiral quark model from the instanton vacuum

    SciTech Connect

    Nam, Seung-il; Kim, Hyun-Chul

    2006-10-01

    We investigate the leading-twist light-cone distribution amplitudes for the pion and kaon based on the gauge-invariant nonlocal chiral quark model from the instanton vacuum in the presence of external axial-vector currents. We find that the nonlocal contribution from the gauge invariance has much effects on the pion distribution amplitudes, while it changes mildly the kaon ones. We also study the Gegenbauer moments of the distribution amplitudes and compare them with the empirical analysis of the CLEO data.

  7. Anthropogenic carbon in the East Greenland Current

    NASA Astrophysics Data System (ADS)

    Jutterström, Sara; Jeansson, Emil

    2008-07-01

    Sections of dissolved inorganic anthropogenic carbon ( CTanthro) based on 2002 data in the East Greenland Current (EGC) are presented. The CTanthro has been estimated using a model based on optimum multiparameter analysis with predefined source water types. Values of CTanthro have been assigned to the source water types through age estimations based on the transit time distribution (TTD) technique. The validity of this approach is discussed and compared to other methods. The results indicated that the EGC had rather high levels of CTanthro in the whole water column, and the anthropogenic signal of the different source areas were detected along the southward transit. We estimated an annual transport of CTanthro with the Denmark Strait overflow ( σθ > 27.8 kg m -3) of ∼0.036 ± 0.005 Gt C y -1. The mean CTanthro concentration in this density range was ∼30 μmol kg -1. The main contribution was from Atlantic derived waters, the Polar Intermediate Water and the Greenland Sea Arctic Intermediate Water.

  8. EFFECTS OF PH AND PHOSPHATE ON METAL DISTRIBUTION WITH EMPHASIS ON AS SPECIATION AND MOBILIZATION IN SOILS FROM A LEAD SMELTING SITE

    EPA Science Inventory

    Arsenic in soils from the Asarco Lead Smelter in East Helena, Montana was characterized by X-ray absorption spectroscopy (XAS). As oxidation state and geochemical speciation were analyzed as a function of depth (two sampling sites) and surface distribution. These results were c...

  9. Dynamical next-to-next-to-leading order parton distributions and the perturbative stability of F{sub L}(x,Q{sup 2})

    SciTech Connect

    Glueck, M.; Reya, E.; Pisano, C.

    2008-04-01

    Recent measurements for F{sub 2}(x,Q{sup 2}) have been analyzed in terms of the 'dynamical' and 'standard' parton model approach at next-to-leading order (NLO) and next-to-next-to-leading order (NNLO) of perturbative QCD. Having fixed the relevant NLO and NNLO parton distributions, we present the implications and predictions for the longitudinal structure function F{sub L}(x,Q{sup 2}). It is shown that the previously noted extreme perturbative NNLO/NLO instability of F{sub L}(x,Q{sup 2}) is an artifact of the commonly utilized 'standard' gluon distributions. In particular it is demonstrated that using the appropriate--dynamically generated--parton distributions at NLO and NNLO, F{sub L}(x,Q{sup 2}) turns out to be perturbatively rather stable already for Q{sup 2}{>=}O(2-3 GeV{sup 2})

  10. Prediction of in-depth oxidation distribution of reinforced carbon-carbon materials for Space Shuttle leading edges

    NASA Technical Reports Server (NTRS)

    Medford, J. E.

    1977-01-01

    A method was developed for predicting oxidation distribution through the thickness of reinforced carbon-carbon material in an earth atmospheric entry environment. A mathematical model was developed which describes oxygen diffusion and reaction rates within material pores. Pertinent rate constants were derived, and material mass loss was computed for a range of temperatures and pressures. Results indicate that both temperature and pressure have an important effect on mass loss distribution. Analytical results were quite consistent with results of ground oxidation tests.

  11. Giant natural fluctuation models and anthropogenic warming

    NASA Astrophysics Data System (ADS)

    Lovejoy, S.; Rio Amador, L.; Hébert, R.; Lima, I.

    2016-08-01

    Explanations for the industrial epoch warming are polarized around the hypotheses of anthropogenic warming (AW) and giant natural fluctuations (GNFs). While climate sceptics have systematically attacked AW, up until now they have only invoked GNFs. This has now changed with the publication by D. Keenan of a sample of 1000 series from stochastic processes purporting to emulate the global annual temperature since 1880. While Keenan's objective was to criticize the International Panel on Climate Change's trend uncertainty analysis (their assumption that residuals are only weakly correlated), for the first time it is possible to compare a stochastic GNF model with real data. Using Haar fluctuations, probability distributions, and other techniques of time series analysis, we show that his model has unrealistically strong low-frequency variability so that even mild extrapolations imply ice ages every ≈1000 years. Helped by statistics, the GNF model can easily be scientifically rejected.

  12. Anthropogenic sulfur dioxide emissions: 1850-2005

    SciTech Connect

    Smith, S. J.; Van Aardenne, J.; Klimont, Z.; Andres, Robert Joseph; Volke, A.; Delgado Arias, S

    2011-01-01

    Sulfur aerosols impact human health, ecosystems, agriculture, and global and regional climate. A new annual estimate of anthropogenic global and regional sulfur dioxide emissions has been constructed spanning the period 1850 2005 using a bottom-up mass balance method, calibrated to country-level inventory data. Global emissions peaked in the early 1970s and decreased until 2000, with an increase in recent years due to increased emissions in China, international shipping, and developing countries in general. An uncertainty analysis was conducted including both random and systemic uncertainties. The overall global uncertainty in sulfur dioxide emissions is relatively small, but regional uncertainties ranged up to 30%. The largest contributors to uncertainty at present are emissions from China and international shipping. Emissions were distributed on a 0.5 grid by sector for use in coordinated climate model experiments.

  13. Response of air stagnation frequency to anthropogenically enhanced radiative forcing.

    PubMed

    Horton, Daniel E; Harshvardhan; Diffenbaugh, Noah S

    2012-01-01

    Stagnant atmospheric conditions can lead to hazardous air quality by allowing ozone and particulate matter to accumulate and persist in the near-surface environment. By changing atmospheric circulation and precipitation patterns, global warming could alter the meteorological factors that regulate air stagnation frequency. We analyze the response of the National Climatic Data Center (NCDC) Air Stagnation Index (ASI) to anthropogenically enhanced radiative forcing using global climate model projections of late-21(st) century climate change (SRES A1B scenario). Our results indicate that the atmospheric conditions over the highly populated, highly industrialized regions of the eastern United States, Mediterranean Europe, and eastern China are particularly sensitive to global warming, with the occurrence of stagnant conditions projected to increase 12-to-25% relative to late-20(th) century stagnation frequencies (3-18+ days/year). Changes in the position/strength of the polar jet, in the occurrence of light surface winds, and in the number of precipitation-free days all contribute to more frequent late-21(st) century air mass stagnation over these high-population regions. In addition, we find substantial inter-model spread in the simulated response of stagnation conditions over some regions using either native or bias corrected global climate model simulations, suggesting that changes in the atmospheric circulation and/or the distribution of precipitation represent important sources of uncertainty in the response of air quality to global warming. PMID:23284587

  14. Response of air stagnation frequency to anthropogenically enhanced radiative forcing

    PubMed Central

    Horton, Daniel E.; Harshvardhan; Diffenbaugh, Noah S.

    2012-01-01

    Stagnant atmospheric conditions can lead to hazardous air quality by allowing ozone and particulate matter to accumulate and persist in the near-surface environment. By changing atmospheric circulation and precipitation patterns, global warming could alter the meteorological factors that regulate air stagnation frequency. We analyze the response of the National Climatic Data Center (NCDC) Air Stagnation Index (ASI) to anthropogenically enhanced radiative forcing using global climate model projections of late-21st century climate change (SRES A1B scenario). Our results indicate that the atmospheric conditions over the highly populated, highly industrialized regions of the eastern United States, Mediterranean Europe, and eastern China are particularly sensitive to global warming, with the occurrence of stagnant conditions projected to increase 12-to-25% relative to late-20th century stagnation frequencies (3-18+ days/year). Changes in the position/strength of the polar jet, in the occurrence of light surface winds, and in the number of precipitation-free days all contribute to more frequent late-21st century air mass stagnation over these high-population regions. In addition, we find substantial inter-model spread in the simulated response of stagnation conditions over some regions using either native or bias corrected global climate model simulations, suggesting that changes in the atmospheric circulation and/or the distribution of precipitation represent important sources of uncertainty in the response of air quality to global warming. PMID:23284587

  15. Anthropogenic influence on forest landscape in the Khumbu valley, Nepal

    NASA Astrophysics Data System (ADS)

    Lingua, Emanuele; Garbarino, Matteo; Urbinati, Carlo; Carrer, Marco

    2013-04-01

    High altitude Himalayan regions are geo-dynamically very active and very sensitive to natural and anthropogenic disturbances due to their steep slopes, variations of precipitations with elevation and short growing periods. Nonetheless, even in this remote region human pressure is often the most important factor affecting forest landscape. In the last decades the firewood demand has increased each year between September to December. The increase in the number of tourists, mountaineering, guides, porters, carpenters, lodges lead to a peak in the use of fuelwood. In order to understand anthropogenic impacts on forest, resources landscape and stand scale dynamics were analyzed in the Sagarmatha National Park (SNP) and its Buffer Zone in the Khumbu Valley (Nepal, Eastern Himalaya). Biological and historical data sources were employed, and a multi-scale approach was adopted to capture the influence of human activities on the distribution of tree species and forest structure. Stand structure and a range of environmental variables were sampled in 197 20x20 m square plots, and land use and anthropogenic variables were derived in a GIS environment (thematic maps and IKONOS, Landsat and Terra ASTER satellite images). We used multivariate statistical analyses to relate forest structure, anthropogenic influences, land uses, and topography. Fuel wood is the prime source of energy for cooking (1480-1880 Kg/person/year) and Quercus semecarpifolia, Rhododendron arboreum and Pinus wallichiana, among the others, are the most exploited species. Due to lack of sufficient energy sources deforestation is becoming a problem in the area. This might be a major threat causing soil erosion, landslides and other natural hazards. Among the 25 species of trees that were found in the Buffer Zone Community Forests of SNP, Pinus wallichiana, Lyonia ovalifolia, Quercus semecarpifolia and Rhododendron arboreum are the dominant species. The total stand density ranged from 228 to 379 tree/ha and the

  16. Ecology of estuaries: Anthropogenic effects

    SciTech Connect

    Kennish, M.J.

    1992-01-01

    Estuaries and near-shore oceanic water are subjected to a multitude of human wastes. The principal objective of this book is to examine anthropogenic effects on estuaries, and it focuses primarily on contaminants in coastal systems. Covered within various chapters are the following topics: waste disposal strategies; definition and classification of pollutants (including organic loading, oil pollution, polynuclear aromatic hydrocarbons; chlorinated hydrocarbons; heavy metals; radionuclides) biological impacts; waste management; impacts of power plants; dredging and spoil disposal; case studies, primarily Chesapeake Bay. The book serves as a text and as a reference.

  17. The Occurrence of Contaminant Accumulation in Lead Pipe Scales from Domestic Drinking Water Distribution Systems-ABSTRACT

    EPA Science Inventory

    Previous work has shown that contaminants such as Al, As and Ra, can accumulate in drinking water distribution system solids. The release of accumulated contaminants back into the water supply could conceivably result in elevated levels at consumers’ taps. The current regulatory...

  18. Turbine Vane External Heat Transfer. Volume 1: Analytical and Experimental Evaluation of Surface Heat Transfer Distributions with Leading Edge Showerhead Film Cooling

    NASA Technical Reports Server (NTRS)

    Turner, E. R.; Wilson, M. D.; Hylton, L. D.; Kaufman, R. M.

    1985-01-01

    Progress in predictive design capabilities for external heat transfer to turbine vanes was summarized. A two dimensional linear cascade (previously used to obtain vane surface heat transfer distributions on nonfilm cooled airfoils) was used to examine the effect of leading edge shower head film cooling on downstream heat transfer. The data were used to develop and evaluate analytical models. Modifications to the two dimensional boundary layer model are described. The results were used to formulate and test an effective viscosity model capable of predicting heat transfer phenomena downstream of the leading edge film cooling array on both the suction and pressure surfaces, with and without mass injection.

  19. Anthropogenic radionuclides in the environment

    SciTech Connect

    Hu, Q; Weng, J; Wang, J

    2007-11-15

    Studies of radionuclides in the environment have entered a new era with the renaissance of nuclear energy and associated fuel reprocessing, geological disposal of high-level nuclear wastes, and concerns about national security with respect to nuclear non-proliferation. This work presents an overview of anthropogenic radionuclide contamination in the environment, as well as the salient geochemical behavior of important radionuclides. We first discuss the following major anthropogenic sources and current development that contribute to the radionuclide contamination of the environment: (1) nuclear weapons program; (2) nuclear weapons testing; (3) nuclear power plants; (4) commercial fuel reprocessing; (5) geological repository of high-level nuclear wastes, and (6) nuclear accidents. Then, we summarize the geochemical behavior for radionuclides {sup 99}Tc, {sup 129}I, and {sup 237}Np, because of their complex geochemical behavior, long half-lives, and presumably high mobility in the environment. Biogeochemical cycling and environment risk assessment must take into account speciation of these redox-sensitive radionuclides.

  20. Diagnosing Possible Anthropogenic Contributions to Colorado Floods in September 2013.

    NASA Astrophysics Data System (ADS)

    Pall, P.; Patricola, C. M.; Wehner, M. F.; Stone, D. A.

    2015-12-01

    Unusually heavy rainfall occurred over the Colorado Front Range during the second week of September 2013, with record or near-record totals recorded in several locations. It was associated predominantly with a stationary large-scale weather pattern (akin to the North American Monsoon, which occurs earlier in the year) that drove a strong plume of deep moisture inland from the Gulf of Mexico and eastern tropical Pacific towards the Front Range foothills. The resulting floods across the South Platte River basin impacted several thousands of people and many homes, roads, and businesses. A recent study using observational-based re-analysis to drive the regional WRF model finds that, given very little change in the large-scale weather pattern, there is an increase in atmospheric water vapour over northeast Colorado under anthropogenic climate warming, with a positive dynamical feedback drawing in moisture from further afield. This leads to a substantial increase in the magnitude and odds of heavy rainfall occurring over northeast Colorado during the rainy week of September 2013. Here we develop this work by including a hydrological modelling component in order to investigate any anthropogenic influence on the actual flood magnitude and occurrence across the South Platte basin during that time. We use WRF precipitation output from the aforementioned study - in both anthropogenic and non-anthropogenic configurations for September 2013 - to drive the recently developed high-resolution WRF-Hydro model over the basin and generate river runoff. Thus by comparing changes in runoff under the anthropogenic / non-anthropogenic driving conditions we assess any influence on the magnitude and odds of flood occurrence. Integral to this, we test the sensitivity of our results to hydrological parameters, such as infiltration, base flow, and land use/cover.

  1. Lead distribution and its potential risk to the environment: lesson learned from environmental monitoring of abandon mine.

    PubMed

    Nobuntou, Wanida; Parkpian, Preeda; Oanh, Nguyen Thi Kim; Noomhorm, Athapol; Delaune, R D; Jugsujinda, Aroon

    2010-11-01

    There are many abandon and existing mines (tin, lead and zinc) in the mountainous areas of Thailand. Toxic elements including heavy metals such as lead (Pb), cadmium (Cd) and arsenic (As) have been released and transported from the mining sites to the adjacent landscape. In Thong Pha Phum District, Kanchanaburi Province, Thailand Pb contamination in the vicinity of the mine has occurred which could lead to potential health problems in downstream communities. To better understand current status of Pb contamination and accumulation in the surrounding environment and potential health impact, surface sediment, soil and plant samples were collected seasonally from representative monitoring sites along the aquatic track or flow regime. Potential health risk was determined using hazard quotient (HQ) as an index for local inhabitants who consume rice. Environmental monitoring illustrated that Pb concentrations in the surface sediment was as high as 869.4 mg kg(-1) dry weight and varied differently among stations sampled. Lead content in agricultural soil ranged between 137.8 to 613.5 mg kg(-1) dry weight and was inversely proportion to the distance from the point source. Moreover Pb was transported from the point source to down hill areas. At the highly polluted monitoring stations (S1, S2, and S3), concentrations of Pb exceeded the maximum allowable concentration for Pb in agricultural soil (300 mg kg(-1)) by 1.7-2 times. The Pb in soil was primarily associated with Fe/Mn oxides bound fraction (46-56%) followed by the organic bound fraction (25-30%). Lead uptake by plant varied and was species dependent. However root and tuber crops like cassava (19.92 mg Pb kg(-1) dry weight) and curcumin (3.25 mg Pb kg(-1) dry weight) could have removed Pb from the soil which suggest growing root crops in Pb contaminated soils should be avoided. However Cd, a co-contaminant at one of monitored stations (S4) yielded rice grain with Cd exceeding the maximum allowable concentration

  2. Attributing Atmospheric Methane to Anthropogenic Emission Sources.

    PubMed

    Allen, David

    2016-07-19

    Methane is a greenhouse gas, and increases in atmospheric methane concentration over the past 250 years have driven increased radiative forcing of the atmosphere. Increases in atmospheric methane concentration since 1750 account for approximately 17% of increases in radiative forcing of the atmosphere, and that percentage increases by approximately a factor of 2 if the effects of the greenhouse gases produced by the atmospheric reactions of methane are included in the assessment. Because of the role of methane emissions in radiative forcing of the atmosphere, the identification and quantification of sources of methane emissions is receiving increased scientific attention. Methane emission sources include biogenic, geogenic, and anthropogenic sources; the largest anthropogenic sources are natural gas and petroleum systems, enteric fermentation (livestock), landfills, coal mining, and manure management. While these source categories are well-known, there is significant uncertainty in the relative magnitudes of methane emissions from the various source categories. Further, the overall magnitude of methane emissions from all anthropogenic sources is actively debated, with estimates based on source sampling extrapolated to regional or national scale ("bottom-up analyses") differing from estimates that infer emissions based on ambient data ("top-down analyses") by 50% or more. To address the important problem of attribution of methane to specific sources, a variety of new analytical methods are being employed, including high time resolution and highly sensitive measurements of methane, methane isotopes, and other chemical species frequently associated with methane emissions, such as ethane. This Account describes the use of some of these emerging measurements, in both top-down and bottom-up methane emission studies. In addition, this Account describes how data from these new analytical methods can be used in conjunction with chemical mass balance (CMB) methods for source

  3. Attributing Atmospheric Methane to Anthropogenic Emission Sources.

    PubMed

    Allen, David

    2016-07-19

    Methane is a greenhouse gas, and increases in atmospheric methane concentration over the past 250 years have driven increased radiative forcing of the atmosphere. Increases in atmospheric methane concentration since 1750 account for approximately 17% of increases in radiative forcing of the atmosphere, and that percentage increases by approximately a factor of 2 if the effects of the greenhouse gases produced by the atmospheric reactions of methane are included in the assessment. Because of the role of methane emissions in radiative forcing of the atmosphere, the identification and quantification of sources of methane emissions is receiving increased scientific attention. Methane emission sources include biogenic, geogenic, and anthropogenic sources; the largest anthropogenic sources are natural gas and petroleum systems, enteric fermentation (livestock), landfills, coal mining, and manure management. While these source categories are well-known, there is significant uncertainty in the relative magnitudes of methane emissions from the various source categories. Further, the overall magnitude of methane emissions from all anthropogenic sources is actively debated, with estimates based on source sampling extrapolated to regional or national scale ("bottom-up analyses") differing from estimates that infer emissions based on ambient data ("top-down analyses") by 50% or more. To address the important problem of attribution of methane to specific sources, a variety of new analytical methods are being employed, including high time resolution and highly sensitive measurements of methane, methane isotopes, and other chemical species frequently associated with methane emissions, such as ethane. This Account describes the use of some of these emerging measurements, in both top-down and bottom-up methane emission studies. In addition, this Account describes how data from these new analytical methods can be used in conjunction with chemical mass balance (CMB) methods for source

  4. Spatial distribution of lead in soils of Pb-Zn mining and smelting area of the Mitrovica Region, Republic of Kosovo.

    PubMed

    Aliu, Milihate; Šajn, Robert; Stafilov, Trajče

    2016-01-01

    An area of 301 km(2) in the Mitrovica region, Republic of Kosovo, was selected in order to evaluate the lead distribution in the soil. In total, 156 surface soil samples (0 to 5 cm) were collected. The lead content was determined by inductively coupled plasma-mass spectrometry (ICP-MS). It was found that the average content of lead in the surface soil is 450 mg/kg (with a range of 35-35000 mg/kg). For the entire study area 93% of the samples had lead levels above 100 mg/kg, eight samples below 100 mg/kg and only one sample had lead levels at 30 mg/kg. The effects of mining and metallurgical activities were further assessed using the enrichment factor (EF) value. The lead average exceeded the optimum value specified in the New Dutchlist by five times, while EU average value exceeded it up to 20 times. An area of 113 km(2) of the study area was enriched with Pb higher than the action value (530 mg/kg) while 287 km(2) had significant concentration levels with Pb (358 mg/kg) higher than the optimal value (85 mg/kg), according to New Dutchlist.

  5. Hadronic Single Inclusive k{sub perpendicular} Distributions inside One Jet Beyond the Modified-Leading-Log Approximation

    SciTech Connect

    Arleo, Francois; Perez-Ramos, Redamy; Machet, Bruno

    2008-02-08

    The hadronic k{sub perpendicular} spectrum inside one jet is determined including corrections of relative magnitude O({radical}({alpha}{sub s})) with respect to the modified-leading-logarithmic approximation (MLLA), at and beyond the limiting spectrum (assuming an infrared cutoff Q{sub 0}={lambda}{sub QCD} and Q{sub 0}{ne}{lambda}{sub QCD}). The agreement between our results and preliminary measurements by the CDF Collaboration is impressive, much better than at MLLA, pointing out very small overall nonperturbative contributions.

  6. Continental anthropogenic primary particle number emissions

    NASA Astrophysics Data System (ADS)

    Paasonen, Pauli; Kupiainen, Kaarle; Klimont, Zbigniew; Visschedijk, Antoon; Denier van der Gon, Hugo A. C.; Amann, Markus

    2016-06-01

    Atmospheric aerosol particle number concentrations impact our climate and health in ways different from those of aerosol mass concentrations. However, the global, current and future anthropogenic particle number emissions and their size distributions are so far poorly known. In this article, we present the implementation of particle number emission factors and the related size distributions in the GAINS (Greenhouse Gas-Air Pollution Interactions and Synergies) model. This implementation allows for global estimates of particle number emissions under different future scenarios, consistent with emissions of other pollutants and greenhouse gases. In addition to determining the general particulate number emissions, we also describe a method to estimate the number size distributions of the emitted black carbon particles. The first results show that the sources dominating the particle number emissions are different to those dominating the mass emissions. The major global number source is road traffic, followed by residential combustion of biofuels and coal (especially in China, India and Africa), coke production (Russia and China), and industrial combustion and processes. The size distributions of emitted particles differ across the world, depending on the main sources: in regions dominated by traffic and industry, the number size distribution of emissions peaks in diameters range from 20 to 50 nm, whereas in regions with intensive biofuel combustion and/or agricultural waste burning, the emissions of particles with diameters around 100 nm are dominant. In the baseline (current legislation) scenario, the particle number emissions in Europe, Northern and Southern Americas, Australia, and China decrease until 2030, whereas especially for India, a strong increase is estimated. The results of this study provide input for modelling of the future changes in aerosol-cloud interactions as well as particle number related adverse health effects, e.g. in response to tightening

  7. Distribution of copper, lead, zinc, mercury, and arsenic in the surface sediments off the coast of northwestern Alaska

    USGS Publications Warehouse

    Barnes, Peter; Leong, Kam W.

    1971-01-01

    Increasing interest in potentially harmful substances utilized and discarded by man has raised question about the normal distribution of chemical elements in the natural environment.  This interest prompted a baseline study of a pristine region off the northern coast of Alaska.  Information was gathered on currents, water clarity, nutrients, temperature and salinity, zooplakton, benthic communities, neritic fauna, bird and mammal population and pesticide residues, sediment composition and chemistry of the sediments and their interstitial waters.  This information will provide a base for ascertaining and evaluating future changes and for assessment of the potential hazard in this region and ecosystems elsewhere.

  8. Interruption of Infection Transmission in the Onchocerciasis Focus of Ecuador Leading to the Cessation of Ivermectin Distribution

    PubMed Central

    Lovato, Raquel; Guevara, Angel; Guderian, Ronald; Proaño, Roberto; Unnasch, Thomas; Criollo, Hipatia; Hassan, Hassan K.; Mackenzie, Charles D.

    2014-01-01

    Introduction: A clinically significant endemic focus of onchocerciasis existing in Esmeraldas Province, coastal Ecuador has been under an ivermectin mass drug administration program since 1991. The main transmitting vector in this area is the voracious blackfly, Simulium exiguum. This paper describes the assessments made that support the decision to cease mass treatment. Methodology and Principle Findings: Thirty-five rounds of ivermectin treatment occurred between 1991–2009 with 29 of these carrying >85% coverage. Following the guidelines set by WHO for ceasing ivermectin distribution the impact on parasite transmission was measured in the two vector species by an O-150 PCR technique standard for assessing for the presence of Onchocerca volvulus. Up to seven collection sites in three major river systems were tested on four occasions between 1995 and 2008. The infectivity rates of 65.0 (CI 39–101) and 72.7 (CI 42–116) in 1995 dropped to zero at all seven collection sites by 2008. Assessment for the presence of antibodies against O. volvulus was made in 2001, 2006, 2007 and 2008 using standard ELISA assays for detecting anti-Ov16 antibodies. None of total of 1810 children aged 1–15 years (between 82 and 98% of children present in the surveyed villages) tested in the above years were found to be carrying antibodies to this antigen. These findings were the basis for the cessation of mass drug treatment with ivermectin in 2009. Significance: This fulfillment of the criteria for cessation of mass distribution of ivermectin in the only known endemic zone of onchocerciasis in Ecuador moves the country into the surveillance phase of official verification for national elimination of transmission of infection. These findings indicate that ivermectin given twice a year with greater than 85% of the community can move a program to the final stages of verification of transmission interruption. PMID:24853587

  9. Anthropogenic impacts on Costa Rican bat parasitism are sex specific.

    PubMed

    Frank, Hannah K; Mendenhall, Chase D; Judson, Seth D; Daily, Gretchen C; Hadly, Elizabeth A

    2016-07-01

    While anthropogenic impacts on parasitism of wildlife are receiving growing attention, whether these impacts vary in a sex-specific manner remains little explored. Differences between the sexes in the effect of parasites, linked to anthropogenic activity, could lead to uneven sex ratios and higher population endangerment. We sampled 1108 individual bats in 18 different sites across an agricultural mosaic landscape in southern Costa Rica to investigate the relationships between anthropogenic impacts (deforestation and reductions in host species richness) and bat fly ectoparasitism of 35 species of Neotropical bats. Although female and male bat assemblages were similar across the deforestation gradient, bat fly assemblages tracked their hosts closely only on female bats. We found that in female hosts, parasite abundance per bat decreased with increasing bat species richness, while in male hosts, parasite abundance increased. We hypothesize the differences in the parasite-disturbance relationship are due to differences in roosting behavior between the sexes. We report a sex-specific parasite-disturbance relationship and argue that sex differences in anthropogenic impacts on wildlife parasitism could impact long-term population health and survival. PMID:27547321

  10. [Effects of Different Modifier Concentrations on Lead-Zinc Tolerance, Subcellular Distribution and Chemical Forms for Four Kinds of Woody Plants].

    PubMed

    Chen, Yong-hua; Zhang, Fu-yun; Wu, Xiao-fu; Liang, Xi; Yuan, Si-wen

    2015-10-01

    Four kinds of lead-zinc tolerant woody plants: Nerium oleander, Koelreuteria paniculata, Paulownia and Boehmeria were used as materials to estimate their enrichment and transferable capacity of lead (Pb) and zinc (Zn) and analyze the subcellular distribution and chemical speciation of Zn and Ph in different parts of plants, under different modifier concentrations (CK group: 100% lead-zinc slag plus a small amount of phosphate fertilizer, improved one: 85% of lead-zinc slag ± 10% peat ± 5% bacterial manure plus a small amount of phosphate fertilizer, improved two: 75% lead-zinc slag ± 20% peat ± 5% bacterial manure ± a small amount of phosphate). Results showed that: (1) The content of Pb, Zn in matrix after planting four kinds of plants was lower than before, no significant difference between improved one and improved two of Nerium oleander and Boehmeria was found, but improved two was better than improved one of Paulownia, while improved one was better than improved two of Koelreuteria paniculata; Four plants had relatively low aboveground enrichment coefficient of Pb and Zn, but had a high transfer coefficient, showed that the appropriate modifier concentration was able to improve the Pb and Zn enrichment and transfer ability of plants. (2) In subcellular distribution, most of Pb and Zn were distributed in plant cell wall components and soluble components while the distribution in cell organelles such as mitochondria, chloroplasts and nucleus component were less. Compared with CK group, two improved group made soluble components of the cell walls of Pb fixation and retention of zinc role in the enhancement. (3) As for the chemical forms of Pb and Zn in plants, the main chemical forms of Pb were hydrochloric acid, sodium chloride and ethanol extractable forms, while other chemical form contents were few, the main chemical forms of Zn were different based on plant type. Compared with CK group, the proportion of the active Pb chemical form in different plant

  11. [Effects of Different Modifier Concentrations on Lead-Zinc Tolerance, Subcellular Distribution and Chemical Forms for Four Kinds of Woody Plants].

    PubMed

    Chen, Yong-hua; Zhang, Fu-yun; Wu, Xiao-fu; Liang, Xi; Yuan, Si-wen

    2015-10-01

    Four kinds of lead-zinc tolerant woody plants: Nerium oleander, Koelreuteria paniculata, Paulownia and Boehmeria were used as materials to estimate their enrichment and transferable capacity of lead (Pb) and zinc (Zn) and analyze the subcellular distribution and chemical speciation of Zn and Ph in different parts of plants, under different modifier concentrations (CK group: 100% lead-zinc slag plus a small amount of phosphate fertilizer, improved one: 85% of lead-zinc slag ± 10% peat ± 5% bacterial manure plus a small amount of phosphate fertilizer, improved two: 75% lead-zinc slag ± 20% peat ± 5% bacterial manure ± a small amount of phosphate). Results showed that: (1) The content of Pb, Zn in matrix after planting four kinds of plants was lower than before, no significant difference between improved one and improved two of Nerium oleander and Boehmeria was found, but improved two was better than improved one of Paulownia, while improved one was better than improved two of Koelreuteria paniculata; Four plants had relatively low aboveground enrichment coefficient of Pb and Zn, but had a high transfer coefficient, showed that the appropriate modifier concentration was able to improve the Pb and Zn enrichment and transfer ability of plants. (2) In subcellular distribution, most of Pb and Zn were distributed in plant cell wall components and soluble components while the distribution in cell organelles such as mitochondria, chloroplasts and nucleus component were less. Compared with CK group, two improved group made soluble components of the cell walls of Pb fixation and retention of zinc role in the enhancement. (3) As for the chemical forms of Pb and Zn in plants, the main chemical forms of Pb were hydrochloric acid, sodium chloride and ethanol extractable forms, while other chemical form contents were few, the main chemical forms of Zn were different based on plant type. Compared with CK group, the proportion of the active Pb chemical form in different plant

  12. Possibility of a gas-cooled Peltier current lead in the 200 m-class superconducting direct current transmission and distribution system of CASER-2

    NASA Astrophysics Data System (ADS)

    Kawahara, Toshio; Emoto, Masahiko; Watanabe, Hirofumi; Hamabe, Makoto; Yamaguchi, Sataro; Hikichi, Yasuo; Minowa, Masahiro

    Global energy problems should be solved quickly, and superconducting applications are highly demanded as energy saving technologies. Among them, long-distance superconducting transmission seems to be one of the most promising for energy saving by energy sharing. On the other hand, such large systems can be constructed from smaller network systems that can be enhanced by scaling up to the superconducting grid. Reducing heat leak to the low temperature end is the most important aspect of technology for practical superconducting applications, and heat leak reduction at the terminal is a key goal especially for small-length applications. At Chubu University, we have developed a 200 m-class superconducting direct current transmission and distribution system (CASER-2), in which we also used a Peltier current lead (PCL) as heat insulation at the terminal. PCL is composed of a thermoelectric material and a copper lead. In actual transmission and distribution applications, the cables are also cooled by the coolant. After the circulation, the coolant could also be used to cool the current lead. We will discuss the performance of such gas-cooled systems as the total performance of applied superconducting systems using the experimental parameters obtained in CASER-2.

  13. Accumulation and distribution of iron, cadmium, lead and nickel in cucumber plants grown in hydroponics containing two different chelated iron supplies.

    PubMed

    Csog, Árpád; Mihucz, Victor G; Tatár, Eniko; Fodor, Ferenc; Virág, István; Majdik, Cornelia; Záray, Gyula

    2011-07-01

    Cucumber plants grown in hydroponics containing 10 μM Cd(II), Ni(II) and Pb(II), and iron supplied as Fe(III) EDTA or Fe(III) citrate in identical concentrations, were investigated by total-reflection X-ray fluorescence spectrometry with special emphasis on the determination of iron accumulation and distribution within the different plant compartments (root, stem, cotyledon and leaves). The extent of Cd, Ni and Pb accumulation and distribution were also determined. Generally, iron and heavy-metal contaminant accumulation was higher when Fe(III) citrate was used. The accumulation of nickel and lead was higher by about 20% and 100%, respectively, if the iron supply was Fe(III) citrate. The accumulation of Cd was similar. In the case of Fe(III) citrate, the total amounts of Fe taken up were similar in the control and heavy-metal-treated plants (27-31 μmol/plant). Further, the amounts of iron transported from the root towards the shoot of the control, lead- and nickel-contaminated plants were independent of the iron(III) form. Although Fe mobility could be characterized as being low, its distribution within the shoot was not significantly affected by the heavy metals investigated.

  14. Variable flavor number parton distributions and weak gauge and Higgs boson production at hadron colliders at next-to-next-to-leading order of QCD

    SciTech Connect

    Jimenez-Delgado, P.; Reya, E.

    2009-12-01

    Based on our recent next-to-next-to-leading order (NNLO) dynamical parton distributions as obtained in the 'fixed flavor number scheme', we generate radiatively parton distributions in the 'variable flavor number scheme' where the heavy-quark flavors (c,b,t) also become massless partons within the nucleon. Only within this latter factorization scheme are NNLO calculations feasible at present, since the required partonic subprocesses are only available in the approximation of massless initial-state partons. The NNLO predictions for gauge boson production are typically larger (by more than 1{sigma}) than the next-to-leading order (NLO) ones, and rates at LHC energies can be predicted with an accuracy of about 5%, whereas at Tevatron they are more than 2{sigma} above the NLO ones. The NNLO predictions for standard model Higgs-boson production via the dominant gluon fusion process have a total (parton distribution function and scale) uncertainty of about 10% at LHC which almost doubles at the lower Tevatron energies; they are typically about 20% larger than the ones at NLO but the total uncertainty bands overlap.

  15. Distribution and fractionation of cadmium, copper, lead, nickel, and zinc in a calcareous sandy soil receiving municipal solid waste.

    PubMed

    Jalali, Mohsen; Arfania, Hamed

    2011-02-01

    This study was conducted to evaluate the degree of mobility and fractionation of cadmium (Cd), copper (Cu), lead (Pb), nickel (Ni), and zinc (Zn) after the addition of municipal solid sewage sludge (MSS) in a sandy calcareous soil. Treatments were (1) soil application of MSS, (2) soil application of enriched municipal solid waste compost (EMSS), and (3) control soil. The MSS application represented a dose of 200 Mg dry weight per hectare. Soil columns were incubated at room temperature for 15 days and irrigated daily with deionized water to make a total of 505 mm. At the end of leaching experiments, soil samples from each column were divided into 14 layers, each being 1 cm down to 10 and 2.5 cm below that and analyzed for diethylenetriaminepentaacetic acid (DTPA)-extractable Cd, Cu, Pb, Ni, and Zn. The fractionation of the heavy metals in the top five layers of the surface soil samples was investigated by the sequential extraction method. All soil layers of the columns receiving MSS and EMSS had significantly higher concentrations of DTPA-extractable heavy metals than control soil. The maximum concentration of heavy metals in treated soil was in the surface layer and declined significantly with depth. Sequential extraction results showed that in the treated soil, a major proportion of Cd, Pb, and Ni was associated with organic matter (OM) and exchangeable (EXCH) fractions, and a major proportion of Cu and Zn was associated with residual (RES) and OM fractions. Based on relative percent, Pb, Cd, and Ni in the EXCH fraction was higher than Cu and Zn in soil leached with MSS and EMSS, suggesting that application of this MSS to a sandy calcareous soil, at the loading rate used here, may pose a risk in terms of groundwater contamination with Pb, Cd, and Ni.

  16. Divergence genetics analysis reveals historical population genetic processes leading to contrasting phylogeographic patterns in co-distributed species.

    PubMed

    McGovern, Tamara M; Keever, Carson C; Saski, Christopher A; Hart, Michael W; Marko, Peter B

    2010-11-01

    Coalescent samplers are computational time machines for inferring the historical demographic genetic processes that have given rise to observable patterns of spatial genetic variation among contemporary populations. We have used traditional characterizations of population structure and coalescent-based inferences about demographic processes to reconstruct the population histories of two co-distributed marine species, the frilled dog whelk, Nucella lamellosa, and the bat star, Patiria miniata. Analyses of population structure were consistent with previous work in both species except that additional samples of N. lamellosa showed a larger regional genetic break on Vancouver Island (VI) rather than between the southern Alexander Archipelago as in P. miniata. Our understanding of the causes, rather than just the patterns, of spatial genetic variation was dramatically improved by coalescent analyses that emphasized variation in population divergence times. Overall, gene flow was greater in bat stars (planktonic development) than snails (benthic development) but spatially homogeneous within species. In both species, these large phylogeographic breaks corresponded to relatively ancient divergence times between populations rather than regionally restricted gene flow. Although only N. lamellosa shows a large break on VI, population separation times on VI are congruent between species, suggesting a similar response to late Pleistocene ice sheet expansion. The absence of a phylogeographic break in P. miniata on VI can be attributed to greater gene flow and larger effective population size in this species. Such insights put the relative significance of gene flow into a more comprehensive historical biogeographic context and have important implications for conservation and landscape genetic studies that emphasize the role of contemporary gene flow and connectivity in shaping patterns of population differentiation. PMID:21040048

  17. Islands within islands: two montane palaeo-endemic birds impacted by recent anthropogenic fragmentation.

    PubMed

    Robin, V V; Gupta, Pooja; Thatte, Prachi; Ramakrishnan, Uma

    2015-07-01

    Anthropogenic habitat fragmentation of species that live in naturally patchy metapopulations such as mountaintops or sky islands experiences two levels of patchiness. Effects of such multilevel patchiness on species have rarely been examined. Metapopulation theory suggests that patchy habitats could have varied impacts on persistence, dependent on differential migration. It is not known whether montane endemic species, evolutionarily adapted to natural patchiness, are able to disperse between anthropogenic fragments at similar spatial scales as natural patches. We investigated historic and contemporary gene flow between natural and anthropogenic patches across the distribution range of a Western Ghats sky-island-endemic bird species complex. Data from 14 microsatellites for 218 individuals detected major genetic structuring by deep valleys, including one hitherto undescribed barrier. As expected, we found strong effects of historic genetic differentiation across natural patches, but not across anthropogenic fragments. Contrastingly, contemporary differentiation (D(PS)) was higher relative to historic differentiation (F(ST)) in anthropogenic fragments, despite the species' ability to historically traverse shallow valleys. Simulations of recent isolation resulted in high D(PS)/F(ST) values, confirming recent isolation in Western Ghats anthropogenic fragments and also suggesting that this ratio can be used to identifying recent fragmentation in the context of historic connectedness. We suggest that in this landscape, in addition to natural patchiness affecting population connectivity, anthropogenic fragmentation additionally impacts connectivity, making anthropogenic fragments akin to islands within natural islands of montane habitat, a pattern that may be recovered in other sky-island systems.

  18. A dynamic model for the global cycling of anthropogenic vanadium - article no. GB4021

    SciTech Connect

    Hope, B.K.

    2008-12-15

    Vanadium is a major trace metal in fossil fuels. Combustion of residual fuel oils and coal in industrialized economies is recognized as the major source of anthropogenic vanadium. A dynamic mass balance model assessed the influence of anthropogenic inputs on the global distribution and cycling of vanadium between 1700 and 2100 assuming different fossil fuel consumption and V production (mining) scenarios. Anthropogenic V sources were divided into fossil fuel combustion, industrial, and domestic (nonindustrial human activity). By 2050, inputs of anthropogenic V could comprise approximate to 75-85% of those to the atmosphere, approximate to 21-33% to ocean dissolved, approximate to 9-13% to ocean particulate, and approximate to 28-43% of inputs to land; with between approximate to 61-64% of all anthropogenic inputs attributable to fossil fuel combustion. Contributions from combustion and industrial sources, although dominant relative to contributions from domestic sources between 1900 and 2100, were estimated to peak between 2000 and 2050. Accumulation of anthropogenic V on land and in the ocean apparently occurs because natural removal processes are unable to cope with increasing amounts and rates of anthropogenic contributions. Impacts or hazards associated with anthropogenic inputs are unlikely to be discernible or significant on a global scale, but may be measurable and meaningful at smaller scales (coastal waters, continental shelves, and bays), in the locality of specific sources, or given an unfavorable exposure scenario.

  19. Estimation of the Relationship Between Remotely Sensed Anthropogenic Heat Discharge and Building Energy Use

    NASA Technical Reports Server (NTRS)

    Zhou, Yuyu; Weng, Qihao; Gurney, Kevin R.; Shuai, Yanmin; Hu, Xuefei

    2012-01-01

    This paper examined the relationship between remotely sensed anthropogenic heat discharge and energy use from residential and commercial buildings across multiple scales in the city of Indianapolis, Indiana, USA. The anthropogenic heat discharge was estimated with a remote sensing-based surface energy balance model, which was parameterized using land cover, land surface temperature, albedo, and meteorological data. The building energy use was estimated using a GIS-based building energy simulation model in conjunction with Department of Energy/Energy Information Administration survey data, the Assessor's parcel data, GIS floor areas data, and remote sensing-derived building height data. The spatial patterns of anthropogenic heat discharge and energy use from residential and commercial buildings were analyzed and compared. Quantitative relationships were evaluated across multiple scales from pixel aggregation to census block. The results indicate that anthropogenic heat discharge is consistent with building energy use in terms of the spatial pattern, and that building energy use accounts for a significant fraction of anthropogenic heat discharge. The research also implies that the relationship between anthropogenic heat discharge and building energy use is scale-dependent. The simultaneous estimation of anthropogenic heat discharge and building energy use via two independent methods improves the understanding of the surface energy balance in an urban landscape. The anthropogenic heat discharge derived from remote sensing and meteorological data may be able to serve as a spatial distribution proxy for spatially-resolved building energy use, and even for fossil-fuel CO2 emissions if additional factors are considered.

  20. Utilization of laser-assisted analytical methods for monitoring of lead and nutrition elements distribution in fresh and dried Capsicum annuum l. leaves.

    PubMed

    Galiová, Michaela; Kaiser, Jozef; Novotný, Karel; Hartl, Martin; Kizek, Rene; Babula, Petr

    2011-09-01

    Laser induced breakdown spectroscopy (LIBS) and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) have been applied for high-resolution mapping of accumulation and distribution of heavy metal (lead) and nutrition elements (potassium, manganese) in leaves of Capsicum annuum L. samples. Lead was added in a form of Pb(NO₃)₂ at concentration up to 10 mmol L⁻¹ into the vessels that contained tap water and where the 2-months old Capsicum annuum L. plants were grown another seven days. Two dimensional maps of the elements are presented for both laser-assisted analytical methods. Elemental mapping performed on fresh (frozen) and dried Capsicum annuum L. leaves are compared.

  1. Organ distribution and food safety aspects of cadmium and lead in great scallops, Pecten maximus L., and Horse Mussels, Modiolus modiolus L., from Norwegian waters.

    PubMed

    Julshamn, Kaare; Duinker, Arne; Frantzen, Sylvia; Torkildsen, Lise; Maage, Amund

    2008-04-01

    The purpose of the study was to determine the levels and organ distribution of the potentially harmful inorganic elements cadmium and lead in great scallops and horse mussels from unpolluted Norwegian waters. The scallops far exceeded the EU-limit for cadmium in bivalves when all soft tissues were analysed. When only muscle and gonad were included, however, the level of cadmium was acceptable, because cadmium accumulated in the digestive gland with a mean of 52 mg/kg ww (wet weight). In horse mussel, lead was the most problematic element and the concentration varied from 1.4 to 6.6 mg/kg ww with a mean of 3.7 mg/kg ww, exceeding the EU limit of 1.5 mg Pb/kg. The highest concentration of lead was found in the kidney with an average of 120 mg/kg ww and with a maximum value of 240 mg/kg ww. The kidney tissue accounted for approximately 94% of the lead burden in the horse mussel. In order to consume these bivalves, only muscle and gonad of great scallops should be used for consumption and the kidney of horse mussel should be removed prior to consumption.

  2. Interactions of microbial biofilms with toxic trace metals; 2: Prediction and verification of an integrated computer model of lead (II) distribution in the presence of microbial activity

    SciTech Connect

    Hsieh, K.M.; Murgel, G.A.; Lion, L.W.; Shuler, M.L. )

    1994-06-20

    The interfacial interactions of a toxic trace metal, Pb, with a surface modified by a marine film-forming bacterium, Pseudomonas atlantica, were predicted by a structured biofilm model used in conjunction with a chemical speciation model. The validity of the integrated model was tested for batch and continuous operations. Dynamic responses of the biophase due to transient lead concentration increases were also simulated. The reasonable predictions achieved by the model demonstrate its utility in describing trace metal distributions in complex systems where the adsorption properties of inorganic surfaces are modified by adherent bacteria and bacterial production of extracellular polymers.

  3. Identification and distribution of vanadinite (Pb5(V5+O4)3Cl) in lead pipe corrosion by-products.

    PubMed

    Gerke, Tammie L; Scheckel, Kirk G; Schock, Michael R

    2009-06-15

    This study presents the first detailed look at vanadium (V) speciation in drinking water pipe corrosion scales. A pool of 34 scale layers from 15 lead or lead-lined pipes representing eight different municipal drinking water distribution systems in the Northeastern and Midwestern portions of the United States were examined. Diverse synchrotron-based techniques, including bulk XANES (X-ray absorption near edge spectroscopy), micro-XANES, micro-XRD (X-ray diffraction), and micro-XRF (X-ray fluorescence) mapping were employed along with traditional powder XRD, SEM-EDXA (scanning electron microscopy-energy dispersive X-ray analysis), and ICP-OES (inductively coupled plasma-optical emission spectrometry) to evaluate vanadium speciation and distribution in these deposits. Vanadinite (Pb5(VO4)3Cl) was positively identified, and occurred most frequently in the surface layers. Low V(tot) in these waters is likely the limiting factor in the abundance of vanadinite in the pipe scales, along with the existence of divalent lead. The occurrence of V in these samples as a discrete mineral is important because it is formed in the presence of very low concentrations of V in the finished water, it provides a mechanism to concentrate microg x L(-1) amounts of V from the water to near-percent levels in the pipe scales, and the robustness of V accumulation and release in response to water chemistry changes is likely different than it would be with a sorption accumulation mechanism. Extrapolation from limited existing water chemistry data in this study provides an estimate of deltaG(f)degrees for vanadinite as approximately -3443 kJ x mol(-1), or less, leading to a log K(s)0 value of approximately -86 for the reaction Pb5(VO4)3CI(s) equilibrium {Pb2+}5 + {VO4(3-) + {Cl-}, in which {} denotes activity. PMID:19603655

  4. Fission fragment mass and energy distributions as a function of incident neutron energy measured in a lead slowing-down spectrometer

    SciTech Connect

    Romano, C.; Danon, Y.; Block, R.; Thompson, J.; Blain, E.; Bond, E.

    2010-01-15

    A new method of measuring fission fragment mass and energy distributions as a function of incident neutron energy in the range from below 0.1 eV to 1 keV has been developed. The method involves placing a double-sided Frisch-gridded fission chamber in Rensselaer Polytechnic Institute's lead slowing-down spectrometer (LSDS). The high neutron flux of the LSDS allows for the measurement of the energy-dependent, neutron-induced fission cross sections simultaneously with the mass and kinetic energy of the fission fragments of various small samples. The samples may be isotopes that are not available in large quantities (submicrograms) or with small fission cross sections (microbarns). The fission chamber consists of two anodes shielded by Frisch grids on either side of a single cathode. The sample is located in the center of the cathode and is made by depositing small amounts of actinides on very thin films. The chamber was successfully tested and calibrated using 0.41+-0.04 ng of {sup 252}Cf and the resulting mass distributions were compared to those of previous work. As a proof of concept, the chamber was placed in the LSDS to measure the neutron-induced fission cross section and fragment mass and energy distributions of 25.3+-0.5 mug of {sup 235}U. Changes in the mass distributions as a function of incident neutron energy are evident and are examined using the multimodal fission mode model.

  5. Anthropogenic triggering of large earthquakes.

    PubMed

    Mulargia, Francesco; Bizzarri, Andrea

    2014-01-01

    The physical mechanism of the anthropogenic triggering of large earthquakes on active faults is studied on the basis of experimental phenomenology, i.e., that earthquakes occur on active tectonic faults, that crustal stress values are those measured in situ and, on active faults, comply to the values of the stress drop measured for real earthquakes, that the static friction coefficients are those inferred on faults, and that the effective triggering stresses are those inferred for real earthquakes. Deriving the conditions for earthquake nucleation as a time-dependent solution of the Tresca-Von Mises criterion applied in the framework of poroelasticity yields that active faults can be triggered by fluid overpressures < 0.1 MPa. Comparing this with the deviatoric stresses at the depth of crustal hypocenters, which are of the order of 1-10 MPa, we find that injecting in the subsoil fluids at the pressures typical of oil and gas production and storage may trigger destructive earthquakes on active faults at a few tens of kilometers. Fluid pressure propagates as slow stress waves along geometric paths operating in a drained condition and can advance the natural occurrence of earthquakes by a substantial amount of time. Furthermore, it is illusory to control earthquake triggering by close monitoring of minor "foreshocks", since the induction may occur with a delay up to several years.

  6. Anthropogenic triggering of large earthquakes.

    PubMed

    Mulargia, Francesco; Bizzarri, Andrea

    2014-01-01

    The physical mechanism of the anthropogenic triggering of large earthquakes on active faults is studied on the basis of experimental phenomenology, i.e., that earthquakes occur on active tectonic faults, that crustal stress values are those measured in situ and, on active faults, comply to the values of the stress drop measured for real earthquakes, that the static friction coefficients are those inferred on faults, and that the effective triggering stresses are those inferred for real earthquakes. Deriving the conditions for earthquake nucleation as a time-dependent solution of the Tresca-Von Mises criterion applied in the framework of poroelasticity yields that active faults can be triggered by fluid overpressures < 0.1 MPa. Comparing this with the deviatoric stresses at the depth of crustal hypocenters, which are of the order of 1-10 MPa, we find that injecting in the subsoil fluids at the pressures typical of oil and gas production and storage may trigger destructive earthquakes on active faults at a few tens of kilometers. Fluid pressure propagates as slow stress waves along geometric paths operating in a drained condition and can advance the natural occurrence of earthquakes by a substantial amount of time. Furthermore, it is illusory to control earthquake triggering by close monitoring of minor "foreshocks", since the induction may occur with a delay up to several years. PMID:25156190

  7. How anthropogenic noise affects foraging.

    PubMed

    Luo, Jinhong; Siemers, Björn M; Koselj, Klemen

    2015-09-01

    The influence of human activity on the biosphere is increasing. While direct damage (e.g. habitat destruction) is relatively well understood, many activities affect wildlife in less apparent ways. Here, we investigate how anthropogenic noise impairs foraging, which has direct consequences for animal survival and reproductive success. Noise can disturb foraging via several mechanisms that may operate simultaneously, and thus, their effects could not be disentangled hitherto. We developed a diagnostic framework that can be applied to identify the potential mechanisms of disturbance in any species capable of detecting the noise. We tested this framework using Daubenton's bats, which find prey by echolocation. We found that traffic noise reduced foraging efficiency in most bats. Unexpectedly, this effect was present even if the playback noise did not overlap in frequency with the prey echoes. Neither overlapping noise nor nonoverlapping noise influenced the search effort required for a successful prey capture. Hence, noise did not mask prey echoes or reduce the attention of bats. Instead, noise acted as an aversive stimulus that caused avoidance response, thereby reducing foraging efficiency. We conclude that conservation policies may seriously underestimate numbers of species affected and the multilevel effects on animal fitness, if the mechanisms of disturbance are not considered.

  8. Anthropogenic Triggering of Large Earthquakes

    PubMed Central

    Mulargia, Francesco; Bizzarri, Andrea

    2014-01-01

    The physical mechanism of the anthropogenic triggering of large earthquakes on active faults is studied on the basis of experimental phenomenology, i.e., that earthquakes occur on active tectonic faults, that crustal stress values are those measured in situ and, on active faults, comply to the values of the stress drop measured for real earthquakes, that the static friction coefficients are those inferred on faults, and that the effective triggering stresses are those inferred for real earthquakes. Deriving the conditions for earthquake nucleation as a time-dependent solution of the Tresca-Von Mises criterion applied in the framework of poroelasticity yields that active faults can be triggered by fluid overpressures < 0.1 MPa. Comparing this with the deviatoric stresses at the depth of crustal hypocenters, which are of the order of 1–10 MPa, we find that injecting in the subsoil fluids at the pressures typical of oil and gas production and storage may trigger destructive earthquakes on active faults at a few tens of kilometers. Fluid pressure propagates as slow stress waves along geometric paths operating in a drained condition and can advance the natural occurrence of earthquakes by a substantial amount of time. Furthermore, it is illusory to control earthquake triggering by close monitoring of minor “foreshocks”, since the induction may occur with a delay up to several years. PMID:25156190

  9. Contemporary anthropogenic silver cycle: a multilevel analysis.

    PubMed

    Johnson, Jeremiah; Jirikowic, Julie; Bertram, Marlen; van Beers, D; Gordon, R B; Henderson, Kathryn; Klee, R J; Lanzano, Ted; Lifset, R; Oetjen, Lucia; Graedel, T E

    2005-06-15

    Anthropogenic cycling of silver in 1997 is presented using three discrete governmental units: 64 countries encompassing what we believe to be over 90% of global silver flows, 9 world regions, and the entire planet. Using material flow analysis (MFA) techniques, the country level cycles are aggregated to produce the regional cycles, which are used to form a "best estimate" global cycle. Interesting findings include the following: (1) several silver-mining countries export ore and concentrate but also import silver-containing semiproducts and products; (2) the level of development for a country, as indicated by the gross domestic product, is a fair indicator of silver use, but several significant outliers exist; (3) the countries with the greatest mine production include Mexico, the United States, Peru, and China, whereas the United States, Japan, India, Germany, and Italy lead in the fabrication and manufacture of products; (4) North America and Europe's use of silver products exceed that of other regions on a per capita basis; (5) global silver discards, including tailings and separation waste, totaled approximately 57% of the silver mined; (6) approximately 57% of the silver entering waste management globally is recycled; and (7) the amount of silver entering landfills globally is comparable to the amount found in tailings. The results of this MFA lay the basis for further analysis, which in turn can offer insight into natural resource policy, the characterization of environmental impact, and better resource management.

  10. Contemporary anthropogenic silver cycle: a multilevel analysis.

    PubMed

    Johnson, Jeremiah; Jirikowic, Julie; Bertram, Marlen; van Beers, D; Gordon, R B; Henderson, Kathryn; Klee, R J; Lanzano, Ted; Lifset, R; Oetjen, Lucia; Graedel, T E

    2005-06-15

    Anthropogenic cycling of silver in 1997 is presented using three discrete governmental units: 64 countries encompassing what we believe to be over 90% of global silver flows, 9 world regions, and the entire planet. Using material flow analysis (MFA) techniques, the country level cycles are aggregated to produce the regional cycles, which are used to form a "best estimate" global cycle. Interesting findings include the following: (1) several silver-mining countries export ore and concentrate but also import silver-containing semiproducts and products; (2) the level of development for a country, as indicated by the gross domestic product, is a fair indicator of silver use, but several significant outliers exist; (3) the countries with the greatest mine production include Mexico, the United States, Peru, and China, whereas the United States, Japan, India, Germany, and Italy lead in the fabrication and manufacture of products; (4) North America and Europe's use of silver products exceed that of other regions on a per capita basis; (5) global silver discards, including tailings and separation waste, totaled approximately 57% of the silver mined; (6) approximately 57% of the silver entering waste management globally is recycled; and (7) the amount of silver entering landfills globally is comparable to the amount found in tailings. The results of this MFA lay the basis for further analysis, which in turn can offer insight into natural resource policy, the characterization of environmental impact, and better resource management. PMID:16047806

  11. Simulations of the global carbon cycle and anthropogenic CO{sub 2} transient. Annual report

    SciTech Connect

    Sarmiento, J.L.

    1994-07-01

    This research focuses on improving the understanding of the anthropogenic carbon dioxide transient using observations and models of the past and present. In addition, an attempt is made to develop an ability to predict the future of the carbon cycle in response to continued anthropogenic perturbations and climate change. Three aspects of the anthropogenic carbon budget were investigated: (1) the globally integrated budget at the present time; (2) the time history of the carbon budget; and (3) the spatial distribution of carbon fluxes. One of the major activities of this study was the participation in the model comparison study of Enting, et al. [1994] carried out in preparation for the IPCC 1994 report.

  12. Natural versus anthropogenic subsidence of Venice.

    PubMed

    Tosi, Luigi; Teatini, Pietro; Strozzi, Tazio

    2013-09-26

    We detected land displacements of Venice by Persistent Scatterer Interferometry using ERS and ENVISAT C-band and TerraSAR-X and COSMO-SkyMed X-band acquisitions over the periods 1992-2010 and 2008-2011, respectively. By reason of the larger observation period, the C-band sensors was used to quantify the long-term movements, i.e. the subsidence component primarily ascribed to natural processes. The high resolution X-band satellites reveal a high effectiveness to monitor short-time movements as those induced by human activities. Interpolation of the two datasets and removal of the C-band from the X-band map allows discriminating between the natural and anthropogenic components of the subsidence. A certain variability characterizes the natural subsidence (0.9 ± 0.7 mm/yr), mainly because of the heterogeneous nature and age of the lagoon subsoil. The 2008 displacements show that man interventions are responsible for movements ranging from -10 to 2 mm/yr. These displacements are generally local and distributed along the margins of the city islands.

  13. Natural versus anthropogenic subsidence of Venice

    PubMed Central

    Tosi, Luigi; Teatini, Pietro; Strozzi, Tazio

    2013-01-01

    We detected land displacements of Venice by Persistent Scatterer Interferometry using ERS and ENVISAT C-band and TerraSAR-X and COSMO-SkyMed X-band acquisitions over the periods 1992–2010 and 2008–2011, respectively. By reason of the larger observation period, the C-band sensors was used to quantify the long-term movements, i.e. the subsidence component primarily ascribed to natural processes. The high resolution X-band satellites reveal a high effectiveness to monitor short-time movements as those induced by human activities. Interpolation of the two datasets and removal of the C-band from the X-band map allows discriminating between the natural and anthropogenic components of the subsidence. A certain variability characterizes the natural subsidence (0.9 ± 0.7 mm/yr), mainly because of the heterogeneous nature and age of the lagoon subsoil. The 2008 displacements show that man interventions are responsible for movements ranging from −10 to 2 mm/yr. These displacements are generally local and distributed along the margins of the city islands. PMID:24067871

  14. Increased anthropogenic pressure decreases species richness in tropical intertidal reefs.

    PubMed

    Portugal, Adriana Brizon; Carvalho, Fabrício Lopes; de Macedo Carneiro, Pedro Bastos; Rossi, Sergio; de Oliveira Soares, Marcelo

    2016-09-01

    Multiple human stressors affect tropical intertidal sandstone reefs, but little is known about their biodiversity and the environmental impacts of these stressors. In the present study, multiple anthropogenic pressures were integrated using the relative environmental pressure index (REPI) and related to benthic community structure across an intertidal gradient in five sandstone reefs in the tropical South Atlantic coast. Greater species richness and diversity were noted in the low intertidal zones. There was a negative relationship between REPI and species richness, suggesting that increasing anthropogenic pressure has decreased benthic richness. The factors associated with the loss of richness were jetties built to control erosion, urban areas, beachfront kiosks and restaurants, fish markets, and storm sewers with illegal sewage connections. Our results highlight the need for better infrastructure planning and rigorous monitoring of coastal urban areas, since the large influence of multiple human pressures in these reefs leads to biodiversity losses. PMID:27428738

  15. Impacts of atmospheric anthropogenic nitrogen on the open ocean.

    PubMed

    Duce, R A; LaRoche, J; Altieri, K; Arrigo, K R; Baker, A R; Capone, D G; Cornell, S; Dentener, F; Galloway, J; Ganeshram, R S; Geider, R J; Jickells, T; Kuypers, M M; Langlois, R; Liss, P S; Liu, S M; Middelburg, J J; Moore, C M; Nickovic, S; Oschlies, A; Pedersen, T; Prospero, J; Schlitzer, R; Seitzinger, S; Sorensen, L L; Uematsu, M; Ulloa, O; Voss, M; Ward, B; Zamora, L

    2008-05-16

    Increasing quantities of atmospheric anthropogenic fixed nitrogen entering the open ocean could account for up to about a third of the ocean's external (nonrecycled) nitrogen supply and up to approximately 3% of the annual new marine biological production, approximately 0.3 petagram of carbon per year. This input could account for the production of up to approximately 1.6 teragrams of nitrous oxide (N2O) per year. Although approximately 10% of the ocean's drawdown of atmospheric anthropogenic carbon dioxide may result from this atmospheric nitrogen fertilization, leading to a decrease in radiative forcing, up to about two-thirds of this amount may be offset by the increase in N2O emissions. The effects of increasing atmospheric nitrogen deposition are expected to continue to grow in the future. PMID:18487184

  16. Increased anthropogenic pressure decreases species richness in tropical intertidal reefs.

    PubMed

    Portugal, Adriana Brizon; Carvalho, Fabrício Lopes; de Macedo Carneiro, Pedro Bastos; Rossi, Sergio; de Oliveira Soares, Marcelo

    2016-09-01

    Multiple human stressors affect tropical intertidal sandstone reefs, but little is known about their biodiversity and the environmental impacts of these stressors. In the present study, multiple anthropogenic pressures were integrated using the relative environmental pressure index (REPI) and related to benthic community structure across an intertidal gradient in five sandstone reefs in the tropical South Atlantic coast. Greater species richness and diversity were noted in the low intertidal zones. There was a negative relationship between REPI and species richness, suggesting that increasing anthropogenic pressure has decreased benthic richness. The factors associated with the loss of richness were jetties built to control erosion, urban areas, beachfront kiosks and restaurants, fish markets, and storm sewers with illegal sewage connections. Our results highlight the need for better infrastructure planning and rigorous monitoring of coastal urban areas, since the large influence of multiple human pressures in these reefs leads to biodiversity losses.

  17. Disruptions in precipitation cycles: Attribution to anthropogenic forcing

    NASA Astrophysics Data System (ADS)

    Tapiador, Francisco J.; Behrangi, Ali; Haddad, Ziad S.; Katsanos, Dimitris; Castro, Manuel

    2016-03-01

    Disruptions of the spatiotemporal distribution of surface precipitation that are induced by global warming may affect Earth's climate more significantly than changes in the total precipitation amount. Identifying such disruptions at global scales is not straightforward, as it requires disentangling a weak signal from comprehensive, gapless data in a 5-D configuration space whose dimensions are latitude, longitude, time, power, and period. Drawing on reliable, state-of-the-art climate model simulations from the fifth phase of the Coupled Model Intercomparison Project (CMIP5) experiments and using well-tested analytical methods, clear changes in the global precipitation cycles have been found for the simulated period 1862-2003. It has also been found that the disruptions may be attributable to anthropogenic forcing. The disruptions are relevant enough to envision significant changes in precipitation timing if human greenhouse gas emissions continue to accumulate in the future. It is noteworthy that the effects of anthropogenic forcings have been found not predominantly in the intra-annual cycles, i.e., in the short-term weather patterns that would be indicative of local effects, but rather in the interannual planetary long-term variability of the atmosphere. This suggests a global, distributed effect of the anthropogenic forcings on precipitation, which in turn is indicative of changes in the precipitation patterns linked with changes in the thermodynamics of the precipitation microphysics and to a lesser extent with the dynamical aspects of the precipitation processes.

  18. Multidisciplinary study on anthropogenic landslides in Nepal

    NASA Astrophysics Data System (ADS)

    Puglia, Christopher; Derron, Marc-Henri; Nicolet, Pierrick; Sudmeier-Rieux, Karen; Jaboyedoff, Michel; Devkota, Sanjay

    2013-04-01

    Nepal is a country in which shallow landslide is a frequent phenomenon. Monsoon is the main triggering factor but anthropogenic influence is often significant too. Indeed, many infrastructures, such as roads or water pipes, are not built in a rigorous way because of a lack of funds and knowledge. In the present study we examine the technical, social and economic issues of landslide management for two sites in Nepal. The first site is located in Sanusiruwari VDC (Sindhupalchock district, central Nepal) and the second one in Namadi VDC (Ramecchap district, central Nepal). Both sites are affected by landslides induced by the construction of hydropower plants. These landslides may threaten the viability of the hydropower plants. At both sites the problems are quite similar, but the first site project is a private one and the second one is a public one implemented by the United Nations Development Programme (UNDP). For both sites, bioengineering methods using Vetiver (Vetyveria zizanioides) plantations is the main stabilization measure. To follow the progression of both landslides, fieldwork observations were conducted before and after the 2012 rainy season, including photogrammetric and distancemeter acquisitions. Main issues were discussed with communities and stakeholders of the hydropower projects through interviews and participatory risk mapping. Main issues include: lack of communication between the project managers and communities leading to conflict and the lack of maintenance of the bio-engineering sites, leading to less effective Vetiver growth and slope stabilization. Comparing the landslide management (technical, social and economic) of the two projects allows to point out some specific issues within an integrated risk perspective.

  19. Microbial DNA records historical delivery of anthropogenic mercury.

    PubMed

    Poulain, Alexandre J; Aris-Brosou, Stéphane; Blais, Jules M; Brazeau, Michelle; Keller, Wendel Bill; Paterson, Andrew M

    2015-12-01

    Mercury (Hg) is an anthropogenic pollutant that is toxic to wildlife and humans, but the response of remote ecosystems to globally distributed Hg is elusive. Here, we use DNA extracted from a dated sediment core to infer the response of microbes to historical Hg delivery. We observe a significant association between the mercuric reductase gene (merA) phylogeny and the timing of Hg deposition. Using relaxed molecular clock models, we show a significant increase in the scaled effective population size of the merA gene beginning ~200 years ago, coinciding with the Industrial Revolution and a coincident strong signal for positive selection acting on residues in the terminal region of the mercuric reductase. This rapid evolutionary response of microbes to changes in the delivery of anthropogenic Hg indicates that microbial genomes record ecosystem response to pollutant deposition in remote regions.

  20. Anthropogenic influence on multidecadal changes in reconstructed global evapotranspiration

    NASA Astrophysics Data System (ADS)

    Douville, H.; Ribes, A.; Decharme, B.; Alkama, R.; Sheffield, J.

    2013-01-01

    Global warming is expected to intensify the global hydrological cycle, with an increase of both evapotranspiration (EVT) and precipitation. Yet, the magnitude and spatial distribution of this global and annual mean response remains highly uncertain. Better constraining land EVT in twenty-first-century climate scenarios is critical for predicting changes in surface climate, including heatwaves and droughts, evaluating impacts on ecosystems and water resources, and designing adaptation policies. Continental scale EVT changes may already be underway, but have never been attributed to anthropogenic emissions of greenhouse gases and sulphate aerosols. Here we provide global gridded estimates of annual EVT and demonstrate that the latitudinal and decadal differentiation of recent EVT variations cannot be understood without invoking the anthropogenic radiative forcings. In the mid-latitudes, the emerging picture of enhanced EVT confirms the end of the dimming decades and highlights the possible threat posed by increasing drought frequency to managing water resources and achieving food security in a changing climate.

  1. Microbial DNA records historical delivery of anthropogenic mercury

    PubMed Central

    Poulain, Alexandre J; Aris-Brosou, Stéphane; Blais, Jules M; Brazeau, Michelle; Keller, Wendel (Bill); Paterson, Andrew M

    2015-01-01

    Mercury (Hg) is an anthropogenic pollutant that is toxic to wildlife and humans, but the response of remote ecosystems to globally distributed Hg is elusive. Here, we use DNA extracted from a dated sediment core to infer the response of microbes to historical Hg delivery. We observe a significant association between the mercuric reductase gene (merA) phylogeny and the timing of Hg deposition. Using relaxed molecular clock models, we show a significant increase in the scaled effective population size of the merA gene beginning ~200 years ago, coinciding with the Industrial Revolution and a coincident strong signal for positive selection acting on residues in the terminal region of the mercuric reductase. This rapid evolutionary response of microbes to changes in the delivery of anthropogenic Hg indicates that microbial genomes record ecosystem response to pollutant deposition in remote regions. PMID:26057844

  2. The dynamic distribution of fluorescent analogues of actin and myosin in protrusions at the leading edge of migrating Swiss 3T3 fibroblasts

    PubMed Central

    1988-01-01

    The formation of protrusions at the leading edge of the cell is an essential step in fibroblast locomotion. Using fluorescent analogue cytochemistry, ratio imaging, multiple parameter analysis, and fluorescence photobleaching recovery, the distribution of actin and myosin was examined in the same protrusions at the leading edge of live, locomoting cells during wound-healing in vitro. We have previously defined two temporal stages of the formation of protrusions: (a) initial protrusion and (b) established protrusion (Fisher et al., 1988). Actin was slightly concentrated in initial protrusions, while myosin was either totally absent or present at extremely low levels at the base of the initial protrusions. In contrast, established protrusions contained diffuse actin and actin microspikes, as well as myosin in both diffuse and structured forms. Actin and myosin were also localized along concave transverse fibers near the base of initial and established protrusions. The dynamics of myosin penetration into a relatively stable, established protrusion was demonstrated by recording sequential images over time. Myosin was shown to be absent from an initial protrusion, but diffuse and punctate myosin was detected in the same protrusion within 1-2 min. Fluorescence photobleaching recovery indicated that myosin was 100% immobile in the region behind the leading edge containing transverse fibers, in comparison to the 21% immobile fraction detected in the perinuclear region. Possible explanations of the delayed penetration of myosin into established protrusions and the implications on the mechanism of protrusion are discussed. PMID:3204122

  3. Disruption of Transcriptional Coactivator Sub1 Leads to Genome-Wide Re-distribution of Clustered Mutations Induced by APOBEC in Active Yeast Genes.

    PubMed

    Lada, Artem G; Kliver, Sergei F; Dhar, Alok; Polev, Dmitrii E; Masharsky, Alexey E; Rogozin, Igor B; Pavlov, Youri I

    2015-05-01

    Mutations in genomes of species are frequently distributed non-randomly, resulting in mutation clusters, including recently discovered kataegis in tumors. DNA editing deaminases play the prominent role in the etiology of these mutations. To gain insight into the enigmatic mechanisms of localized hypermutagenesis that lead to cluster formation, we analyzed the mutational single nucleotide variations (SNV) data obtained by whole-genome sequencing of drug-resistant mutants induced in yeast diploids by AID/APOBEC deaminase and base analog 6-HAP. Deaminase from sea lamprey, PmCDA1, induced robust clusters, while 6-HAP induced a few weak ones. We found that PmCDA1, AID, and APOBEC1 deaminases preferentially mutate the beginning of the actively transcribed genes. Inactivation of transcription initiation factor Sub1 strongly reduced deaminase-induced can1 mutation frequency, but, surprisingly, did not decrease the total SNV load in genomes. However, the SNVs in the genomes of the sub1 clones were re-distributed, and the effect of mutation clustering in the regions of transcription initiation was even more pronounced. At the same time, the mutation density in the protein-coding regions was reduced, resulting in the decrease of phenotypically detected mutants. We propose that the induction of clustered mutations by deaminases involves: a) the exposure of ssDNA strands during transcription and loss of protection of ssDNA due to the depletion of ssDNA-binding proteins, such as Sub1, and b) attainment of conditions favorable for APOBEC action in subpopulation of cells, leading to enzymatic deamination within the currently expressed genes. This model is applicable to both the initial and the later stages of oncogenic transformation and explains variations in the distribution of mutations and kataegis events in different tumor cells. PMID:25941824

  4. Disruption of Transcriptional Coactivator Sub1 Leads to Genome-Wide Re-distribution of Clustered Mutations Induced by APOBEC in Active Yeast Genes.

    PubMed

    Lada, Artem G; Kliver, Sergei F; Dhar, Alok; Polev, Dmitrii E; Masharsky, Alexey E; Rogozin, Igor B; Pavlov, Youri I

    2015-05-01

    Mutations in genomes of species are frequently distributed non-randomly, resulting in mutation clusters, including recently discovered kataegis in tumors. DNA editing deaminases play the prominent role in the etiology of these mutations. To gain insight into the enigmatic mechanisms of localized hypermutagenesis that lead to cluster formation, we analyzed the mutational single nucleotide variations (SNV) data obtained by whole-genome sequencing of drug-resistant mutants induced in yeast diploids by AID/APOBEC deaminase and base analog 6-HAP. Deaminase from sea lamprey, PmCDA1, induced robust clusters, while 6-HAP induced a few weak ones. We found that PmCDA1, AID, and APOBEC1 deaminases preferentially mutate the beginning of the actively transcribed genes. Inactivation of transcription initiation factor Sub1 strongly reduced deaminase-induced can1 mutation frequency, but, surprisingly, did not decrease the total SNV load in genomes. However, the SNVs in the genomes of the sub1 clones were re-distributed, and the effect of mutation clustering in the regions of transcription initiation was even more pronounced. At the same time, the mutation density in the protein-coding regions was reduced, resulting in the decrease of phenotypically detected mutants. We propose that the induction of clustered mutations by deaminases involves: a) the exposure of ssDNA strands during transcription and loss of protection of ssDNA due to the depletion of ssDNA-binding proteins, such as Sub1, and b) attainment of conditions favorable for APOBEC action in subpopulation of cells, leading to enzymatic deamination within the currently expressed genes. This model is applicable to both the initial and the later stages of oncogenic transformation and explains variations in the distribution of mutations and kataegis events in different tumor cells.

  5. Where Will LEAD Lead?

    ERIC Educational Resources Information Center

    Wildman, Louis

    After setting forth eight assumptions concerning the education of educational administrators, findings about the Leadership in Educational Administration Development (LEAD) program are discussed. The analysis is based on the first-year applications, telephone conversations with staff at a majority of the project sites, and additional material…

  6. Anthropogenic versus natural control on trace element and Sr-Nd-Pb isotope stratigraphy in peat sediments of southeast Florida (USA), ˜1500 AD to present

    NASA Astrophysics Data System (ADS)

    Kamenov, George D.; Brenner, Mark; Tucker, Jaimie L.

    2009-06-01

    is oil combustion. The decline in V accumulation after 1970 in the BCM peat corresponds to the introduction of low-sulfur fuels and the change from heavy to distilled oils since the 1970s. After the 1920s, Pb distribution in the peat follows closely the history of alkyl lead consumption in the US, which peaked in the 1970s. Pb isotopes support this inference and furthermore, record changes in the ore sources used to produce leaded gasoline. Idaho ores dominated the peat Pb isotope record until the 1960s, followed by Pb from Mississippi Valley Type deposits from the 1960s to the 1980s. Enhanced fluxes of Cu, Zn, Cd, Sn, Sb, Bi, and to some extent Ni during the last century are likely also related to fossil fuel combustion. Local agricultural activities may also have influenced the geochemical cycles of Cu and Zn. The peat record shows enhanced U accumulation during the last century, possibly related to phosphate mining in western Florida. Sr isotopes in the peat core also reflect anthropogenic influence. The 87Sr/ 86Sr ratio decreases from natural background values in the basal part of the core to lower values in the upper part of the core. The Sr isotope shift is probably related to quarrying operations in Florida, and marks the first time an anthropogenic signal has been detected using the Sr isotope record in a peat core.

  7. LEADING WITH LEADING INDICATORS

    SciTech Connect

    PREVETTE, S.S.

    2005-01-27

    This paper documents Fluor Hanford's use of Leading Indicators, management leadership, and statistical methodology in order to improve safe performance of work. By applying these methods, Fluor Hanford achieved a significant reduction in injury rates in 2003 and 2004, and the improvement continues today. The integration of data, leadership, and teamwork pays off with improved safety performance and credibility with the customer. The use of Statistical Process Control, Pareto Charts, and Systems Thinking and their effect on management decisions and employee involvement are discussed. Included are practical examples of choosing leading indicators. A statistically based color coded dashboard presentation system methodology is provided. These tools, management theories and methods, coupled with involved leadership and employee efforts, directly led to significant improvements in worker safety and health, and environmental protection and restoration at one of the nation's largest nuclear cleanup sites.

  8. New classification of landslide-inducing anthropogenic activities

    NASA Astrophysics Data System (ADS)

    Michoud, C.; Jaboyedoff, M.; Derron, M.-H.; Nadim, F.; Leroi, E.

    2012-04-01

    Although landslides are usually considered typical examples of natural hazards, they can be influenced by human activities. Many examples can be found in the literature about slope instabilities induced by anthropogenic activities, ranging from small superficial landslides to rock avalanches. Research on this topic is of primary importance for understanding and mitigation of landslide risk. Indeed, slope stabilities influenced by human actions contribute significantly to the risk level because, by definition, they are located where elements at risk and people are present. Within the framework of the European project SafeLand "Living with Landslide Risk in Europe", the authors analyzed the landslides induced by anthropogenic factors in Europe and elsewhere (SafeLand deliverable D1.6). During the bibliographical research, it appeared that a complete and illustrated classification on human activities influencing slope stabilities does not yet exist. Therefore, a new classification was introduced by Michoud et al. (2011) about anthropogenic activities affecting slope stability conditions. This classification takes into account conceptual processes leading to landslides (Terzaghi, 1950; Jaboyedoff and Derron, 2005) and the distinction between destabilization factors and triggering factors (Vaunat et al., 1994; Leroueil et al., 1996). The classification was tested and improved through fifty-eight well-documented case studies, even lots of large landslides, such as Elm, Aberfan, Namsos and Rissa landslides, etc. Furthermore, the boundary between natural and "anthropogenic" landslide triggers (e.g. water run-off modified by new land-uses, creating landslides some km farther), and the time during which changes and reactions are to be considered as direct consequences of human activities were highlighted. Finally, anthropogenic influences can also be positive and examples of (non-voluntary) positive human impacts on slope stability are presented. Jaboyedoff, M. and Derron, M

  9. Bimodal size distributions of various organic acids and fatty acids in the marine atmosphere: Influence of anthropogenic aerosols, Asian dusts, and sea spray off the coast of East Asia

    NASA Astrophysics Data System (ADS)

    Mochida, Michihiro; Umemoto, Nobuhiko; Kawamura, Kimitaka; Lim, Ho-Jin; Turpin, Barbara J.

    2007-08-01

    Size-segregated (11 stages) marine aerosol samples were collected off the coast of East Asia during the ACE-Asia campaign in 2001 and were analyzed for homologous series of dicarboxylic acids (C2-C12), ω-oxocarboxylic acids (C2-C4), and n-fatty acids (C16-C30), as well as organic carbon (OC), elemental carbon, and major inorganic ions. Concentrations of OC and major diacids and oxoacids in continental polluted air masses showed predominantly submicron maxima. However, during dusty haze events, supermicron maxima were observed, suggesting a size shift due to the secondary accumulation of these components on dust as well as sea salt particles. Supermicron maxima were also found for palmitic acid (C16 fatty acid) and other lower-molecular-weight fatty acids (LFAs, C16-C19) that are emitted from a microlayer of the ocean surface. In contrast, higher-molecular-weight fatty acids (HFAs, C20-C30) were mainly detected in the submicron mode, presumably due to a substantial contribution of biomass burning aerosols. This study demonstrates a high-variability in the size distributions of organic components (i.e., between submicron and supermicron modes) in the coastal regions off East Asia. Such variations in the physical properties of the marine aerosols may be important in relation to their cloud-condensation-nuclei and light extinction activities.

  10. Late Holocene climate: Natural or anthropogenic?

    NASA Astrophysics Data System (ADS)

    Ruddiman, W. F.; Fuller, D. Q.; Kutzbach, J. E.; Tzedakis, P. C.; Kaplan, J. O.; Ellis, E. C.; Vavrus, S. J.; Roberts, C. N.; Fyfe, R.; He, F.; Lemmen, C.; Woodbridge, J.

    2016-03-01

    For more than a decade, scientists have argued about the warmth of the current interglaciation. Was the warmth of the preindustrial late Holocene natural in origin, the result of orbital changes that had not yet driven the system into a new glacial state? Or was it in considerable degree the result of humans intervening in the climate system through greenhouse gas emissions from early agriculture? Here we summarize new evidence that moves this debate forward by testing both hypotheses. By comparing late Holocene responses to those that occurred during previous interglaciations (in section 2), we assess whether the late Holocene responses look different (and thus anthropogenic) or similar (and thus natural). This comparison reveals anomalous (anthropogenic) signals. In section 3, we review paleoecological and archaeological syntheses that provide ground truth evidence on early anthropogenic releases of greenhouse gases. The available data document large early anthropogenic emissions consistent with the anthropogenic ice core anomalies, but more information is needed to constrain their size. A final section compares natural and anthropogenic interpretations of the δ13C trend in ice core CO2.

  11. Distribution of cadmium, mercury, and lead in different body parts of Baltic herring (Clupea harengus) and perch (Perca fluviatilis): implications for environmental status assessments.

    PubMed

    Boalt, Elin; Miller, Aroha; Dahlgren, Henrik

    2014-01-15

    For heavy metals, quality standards indicating good environmental status are designed to evaluate concentrations in the whole fish body, whereas monitoring of metals is often conducted using muscle or liver tissue. As most metals accumulate at different rates in different parts of fish, data should be adjusted to reflect whole fish body concentrations; however, this requires knowledge on distribution of metal concentrations within fish. Here, concentrations of cadmium, mercury, and lead were analyzed in the liver, muscle and whole fish of herring and perch to create conversion factors for transformation of heavy metal concentrations between these tissues. Species-specific accumulation of metals between muscle, liver, and whole fish were observed. Relationships between different tissues were used to recalculate data from monitoring programs in the Baltic Sea region. Based on whole fish concentrations, environmental status for cadmium and mercury in herring improved compared to assessments based on muscle or liver concentrations alone.

  12. Atmospheric responses to the redistribution of anthropogenic aerosols

    NASA Astrophysics Data System (ADS)

    Wang, Yuan; Jiang, Jonathan H.; Su, Hui

    2015-09-01

    The geographical shift of global anthropogenic aerosols from the developed countries to the Asian continent since the 1980s could potentially perturb the regional and global climate due to aerosol-cloud-radiation interactions. We use an atmospheric general circulation model with different aerosol scenarios to investigate the radiative and microphysical effects of anthropogenic aerosols from different regions on the radiation budget, precipitation, and large-scale circulations. An experiment contrasting anthropogenic aerosol scenarios in 1970 and 2010 shows that the altered cloud reflectivity and solar extinction by aerosols results in regional surface temperature cooling in East and South Asia, and warming in the US and Europe, respectively. These aerosol-induced temperature changes are consistent with the relative temperature trends from 1980 to 2010 over different regions in the reanalysis data. A reduced meridional streamfunction and zonal winds over the tropics as well as a poleward shift of the jet stream suggest weakened and expanded tropical circulations, which are induced by the redistributed aerosols through a relaxing of the meridional temperature gradient. Consequently, precipitation is suppressed in the deep tropics and enhanced in the subtropics. Our assessments of the aerosol effects over the different regions suggest that the increasing Asian pollution accounts for the weakening of the tropics circulation, while the decreasing pollution in Europe and US tends to shift the circulation systems southward. Moreover, the aerosol indirect forcing is predominant over the total aerosol forcing in magnitude, while aerosol radiative and microphysical effects jointly shape the meridional energy distributions and modulate the circulation systems.

  13. Sinks as integrative elements of the anthropogenic metabolism

    NASA Astrophysics Data System (ADS)

    Kral, Ulrich; Brunner, Paul H.

    2015-04-01

    The anthropogenic metabolism is an open system requiring exchange of materials and energy between the anthroposphere and the environment. Material and energy flows are taken from nature and become utilized by men. After utilization, the materials either remain in the anthroposphere as recycling products, or they leave the anthroposphere as waste and emission flows. To accommodate these materials without jeopardizing human and environmental health, limited natural sinks are available; thus, man-made sinks have to be provided where natural sinks are missing or overloaded. The oral presentation (1) suggests a coherent definition of the term "sink", encompassing natural and man-made processes, (2) presents a framework to analyse and evaluate anthropogenic material flows to sinks, based on the tool substance flow analysis and impact assessment methodology, and (3) applies the framework in a case study approach for selected substances such as Copper and Lead in Vienna and Perfluorooctane sulfonate in Switzerland. Finally, the numeric results are aggregated in terms of a new indicator that specifies on a regional scale which fractions of anthropogenic material flows to sinks are acceptable. The following results are obtained: In Vienna, 99% of Cu flows to natural and man-made sinks are in accordance with accepted standards. However, the 0.7% of Cu entering urban soils and the 0.3% entering receiving waters surpass the acceptable level. In the case of Pb, 92% of all flows into sinks prove to be acceptable, but 8% are disposed of in local landfills with limited capacity. For PFOS, 96% of all flows into sinks are acceptable. 4% cannot be evaluated due to a lack of normative criteria, despite posing a risk for human health and the environment. The case studies corroborate the need and constraints of sinks to accommodate inevitable anthropogenic material flows.

  14. A tiered observational system for anthropogenic methane emissions

    NASA Astrophysics Data System (ADS)

    Duren, R. M.; Miller, C. E.; Hulley, G. C.; Hook, S. J.; Sander, S. P.

    2014-12-01

    Improved understanding of anthropogenic methane emissions is required for closing the global carbon budget and addressing priority challenges in climate policy. Several decades of top-down and bottom-up studies show that anthropogenic methane emissions are systematically underestimated in key regions and economic sectors. These uncertainties have been compounded by the dramatic rise of disruptive technologies (e.g., the transformation in the US energy system due to unconventional gas and oil production). Methane flux estimates derived from inverse analyses and aircraft-based mass balance approaches underscore the disagreement in nationally and regionally reported methane emissions as well as the possibility of a long-tail distribution in fugitive emissions spanning the US natural gas supply chain; i.e. a small number of super-emitters may be responsible for most of the observed anomalies. Other studies highlight the challenges of sectoral and spatial attribution of fugitive emissions - including the relative contributions of dairies vs oil and gas production or disentangling the contributions of natural gas transmission, distribution, and consumption or landfill emissions in complex urban environments. Limited observational data remains a foundational barrier to resolving these challenges. We present a tiered observing system strategy for persistent, high-frequency monitoring over large areas to provide remote detection, geolocation and quantification of significant anthropogenic methane emissions across cities, states, basins and continents. We describe how this would both improve confidence in methane emission estimates and expedite resolution of fugitive emissions and leaks. We summarize recent prototype field campaigns that employ multiple vantage points and measurement techniques (including NASA's CARVE and HyTES aircraft and PanFTS instrument on Mt Wilson). We share preliminary results of this tiered observational approach including examples of individual

  15. Anthropogenic heavy metals in the environment of Eurasian Arctic Nature Reserves

    NASA Astrophysics Data System (ADS)

    Vinogradova, Anna; Ivanova, Yulia; Karpov, Alexey

    2014-05-01

    The Russian Arctic Nature Reserves are situated far from the main industrial regions. In spite of this, there are anthropogenic constituents (for example, heavy metals - HM) in the environmental objects (air, water, etc.) and in food chains (plants, birds, and so on). We studied the long-range atmospheric transport of some heavy metals (such as nickel, copper, lead, arsenic, and so on) to four Nature Reserves situated near the shore of the Arctic Ocean - in the Deltas of the Pechora River (Nenets reserve), the Ob River (Gydansky reserve), the Lena River (Ust-Lensky reserve), and at Wrangel Island. The air mass trajectories to each reserve were calculated with the help of the site (www.arl.noaa.gov/ready) for each day of January, April, July, and October for the period of 2001-2010. Analyzing the spatial distributions of these trajectories we studied seasonal variations in air transport of pollution to different Russian Arctic points. Modeling the HM transport in the atmosphere was as in [1]. The main assumption is that HM are transported with submicron aerosol particles. The annual source emissions for the last decade are generalized from the data published by Roshydromet of Russia (http://www.nii-atmosphere.ru/files/PUBL/Eg_2008.doc). The main important source-regions were found for each point. Mean anthropogenic HM concentrations in air and precipitations, as well as HM fluxes onto the surface were estimated at different arctic regions. The spatial distributions of so called "potential function of pollution" were calculated and presented on the maps. These results allow to analyze the role of a real pollution source or of a planned source for each reserve. So, the influence of northern oil and gas industry may be of great importance because of its proximity to the reserves under investigation. The work was partly supported by RFBR, grant No. 14-05-00059. Authors thank the NOAA service for possibility to use their data and products. ________________ 1. Vinogradova

  16. Engineering paradigms and anthropogenic global change

    NASA Astrophysics Data System (ADS)

    Bohle, Martin

    2016-04-01

    This essay discusses 'paradigms' as means to conceive anthropogenic global change. Humankind alters earth-systems because of the number of people, the patterns of consumption of resources, and the alterations of environments. This process of anthropogenic global change is a composite consisting of societal (in the 'noosphere') and natural (in the 'bio-geosphere') features. Engineering intercedes these features; e.g. observing stratospheric ozone depletion has led to understanding it as a collateral artefact of a particular set of engineering choices. Beyond any specific use-case, engineering works have a common function; e.g. civil-engineering intersects economic activity and geosphere. People conceive their actions in the noosphere including giving purpose to their engineering. The 'noosphere' is the ensemble of social, cultural or political concepts ('shared subjective mental insights') of people. Among people's concepts are the paradigms how to shape environments, production systems and consumption patterns given their societal preferences. In that context, engineering is a means to implement a given development path. Four paradigms currently are distinguishable how to make anthropogenic global change happening. Among the 'engineering paradigms' for anthropogenic global change, 'adaptation' is a paradigm for a business-as-usual scenario and steady development paths of societies. Applying this paradigm implies to forecast the change to come, to appropriately design engineering works, and to maintain as far as possible the current production and consumption patterns. An alternative would be to adjust incrementally development paths of societies, namely to 'dovetail' anthropogenic and natural fluxes of matter and energy. To apply that paradigm research has to identify 'natural boundaries', how to modify production and consumption patterns, and how to tackle process in the noosphere to render alterations of common development paths acceptable. A further alternative

  17. Characterization of anthropogenic pollutants in Asian dust

    NASA Astrophysics Data System (ADS)

    Kim, W.; Doh, S.; Yu, Y.

    2008-12-01

    It has well known that the Asian dust storm (ADS) carried anthropogenic pollutants produced in the industrial areas in China to the adjacent East Asian nations including Korea, Japan and Taiwan. In order to characterize such anthropogenic pollutants forced by ADS, detailed electron microscopic observations were carried out on ADS samples collected from the 12 ADS events occurred for the past three years (2004-2006) in Seoul, Korea. In addition, their temporal accumulations were traced using magnetic proxy parameters. As a comparison, companion samples were also collected before- and after- ADS events. We found that anthropogenic signatures in the ADS samples were C, Cr, Pb, S and Zn. Most of these elements were tied with Fe. Therefore the magnetic proxy is highly applicable to trace the quantitative variations in anthropogenic pollutants in ADS. Slightly increasing magnetic concentration parameters reflect increasing amount of anthropogenic pollutants carried by the ADS for the past three years. Connecting with the air- mass trajectories of ADS, the highest magnetic concentration (highest pollution) was observed on the ADS samples from Central China which travelled nearby highly industrialized major cities where foreign multinational enterprises were concentrated.

  18. Lead Poisoning

    MedlinePlus

    ... Experiments Stories Lessons Topics Games Activities Lessons MENU Lead Poisoning Kids Homepage Topics Pollution Lead Poisoning What is ... you can avoid contact with it! Sources of Lead Poisoning HOUSE PAINTS: Before1950, lead-based paint was used ...

  19. Lead Test

    MedlinePlus

    ... to determine lead sources, educating family members about lead poisoning , and instituting follow-up testing to monitor the ... high levels of lead, see the article on Lead Poisoning . The Occupational Safety and Health Administration (OSHA) has ...

  20. Lead Poisoning

    MedlinePlus

    Lead Poisoning What is it and who is affected? Lead is a highly toxic substance, exposure to which ... and children can suffer from the effects of lead poisoning, but childhood lead poisoning is much more frequent. ...

  1. Natural and anthropogenic multi-type hazards for loess territories

    NASA Astrophysics Data System (ADS)

    Mavlyanova, Nadira; Zakirova, Zulfiya

    2013-04-01

    Central Asia (CA) is an extremely large region of varied geography from plains to high, rugged mountains (the region belongs to the Tien-Shan and Pamirs mountain system), vast deserts (Kara Kum, Kyzyl Kum, Taklamakan). The area of the CA region is including the territories of following countries: of Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan and Uzbekistan. CA is particularly exposed to natural hazards like earthquakes, landslide, rockfalls, avalanches, mudflows, flooding, high mountains lakes, sub flooding, and debris flow. This region is one of the most seismically active in the world. In XX century almost in each of five countries have occurred strong earthquakes with magnitude more than 7, led to human victims. Loess soils are widespread in this region in foothills, foothill plains and intermountain depressions. Loess can cause a number of engineering problems because loess undergoes structural collapse and subsidence due to saturation when both the initial dry density and initial water content are low. By comparison of the map of seismic zoning to a map of distribution of loess soils it is easy to be convinced that the territory of the majority of seismic areas are covering by collapsible loess soils with significant thickness (50-150 m). The natural hazards leads to a disaster, if it develops in an urbanized or industrial areas and directly affects people and economic objects. In this case, risk takes place with all its consequences especially on loess soil. In the past a formation of natural hazards was connected generally with two main groups of factors: geological structure and climatic conditions. Now to them the third factor - of human made influence was added. Intensive influence of human activity to the loess territories in CA for last 60 years is destruction of nature balance and changing in environment of loess land in zone with high seismic hazard. This processes primarily associated with following: 1) irrigation of new lands; 2) the

  2. Isolating the anthropogenic component of Arctic warming

    SciTech Connect

    Chylek, Petr; Hengartner, Nicholas; Lesins, Glen; Klett, James D.; Humlum, Ole; Wyatt, Marcia; Dubey, Manvendra K.

    2014-05-28

    Structural equation modeling is used in statistical applications as both confirmatory and exploratory modeling to test models and to suggest the most plausible explanation for a relationship between the independent and the dependent variables. Although structural analysis cannot prove causation, it can suggest the most plausible set of factors that influence the observed variable. We apply structural model analysis to the annual mean Arctic surface air temperature from 1900 to 2012 to find the most effective set of predictors and to isolate the anthropogenic component of the recent Arctic warming by subtracting the effects of natural forcing and variability from the observed temperature. We find that anthropogenic greenhouse gases and aerosols radiative forcing and the Atlantic Multidecadal Oscillation internal mode dominate Arctic temperature variability. Furthermore, our structural model analysis of observational data suggests that about half of the recent Arctic warming of 0.64 K/decade may have anthropogenic causes.

  3. Isolating the anthropogenic component of Arctic warming

    DOE PAGESBeta

    Chylek, Petr; Hengartner, Nicholas; Lesins, Glen; Klett, James D.; Humlum, Ole; Wyatt, Marcia; Dubey, Manvendra K.

    2014-05-28

    Structural equation modeling is used in statistical applications as both confirmatory and exploratory modeling to test models and to suggest the most plausible explanation for a relationship between the independent and the dependent variables. Although structural analysis cannot prove causation, it can suggest the most plausible set of factors that influence the observed variable. We apply structural model analysis to the annual mean Arctic surface air temperature from 1900 to 2012 to find the most effective set of predictors and to isolate the anthropogenic component of the recent Arctic warming by subtracting the effects of natural forcing and variability frommore » the observed temperature. We find that anthropogenic greenhouse gases and aerosols radiative forcing and the Atlantic Multidecadal Oscillation internal mode dominate Arctic temperature variability. Furthermore, our structural model analysis of observational data suggests that about half of the recent Arctic warming of 0.64 K/decade may have anthropogenic causes.« less

  4. Next-to-next-to-leading order QCD analysis of spin-dependent parton distribution functions and their uncertainties: Jacobi polynomials approach

    NASA Astrophysics Data System (ADS)

    Taghavi-Shahri, F.; Khanpour, Hamzeh; Atashbar Tehrani, S.; Alizadeh Yazdi, Z.

    2016-06-01

    We present a first QCD analysis of next-to-next-leading-order (NNLO) contributions of the spin-dependent parton distribution functions (PPDFs) in the nucleon and their uncertainties using the Jacobi polynomial approach. Having the NNLO contributions of the quark-quark and gluon-quark splitting functions in perturbative QCD [Nucl. Phys. B889, 351 (2014)], one can obtain the evolution of longitudinally polarized parton densities of hadrons up to NNLO accuracy of QCD. Very large sets of recent and up-to-date experimental data of spin structure functions of the proton g1p, neutron g1n, and deuteron g1d have been used in this analysis. The predictions for the NNLO calculations of the polarized parton distribution functions as well as the proton, neutron and deuteron polarized structure functions are compared with the corresponding results of the NLO approximation. We form a mutually consistent set of polarized PDFs due to the inclusion of the most available experimental data including the recently high-precision measurements from COMPASS16 experiments [Phys. Lett. B 753, 18 (2016)]. We have performed a careful estimation of the uncertainties using the most common and practical method, the Hessian method, for the polarized PDFs originating from the experimental errors. The proton, neutron and deuteron structure functions and also their first moments, Γp ,n ,d , are in good agreement with the experimental data at small and large momentum fractions of x . We will discuss how our knowledge of spin-dependence structure functions can improve at small and large values of x by the recent COMPASS16 measurements at CERN, the PHENIX and STAR measurements at RHIC, and at the future proposed colliders such as the Electron-Ion Collider.

  5. Quantification of continual anthropogenic pollutants released in swimming pools.

    PubMed

    Keuten, M G A; Peters, M C F M; Daanen, H A M; de Kreuk, M K; Rietveld, L C; van Dijk, J C

    2014-04-15

    Disinfection in swimming pools is often performed by chlorination, However, anthropogenic pollutants from swimmers will react with chlorine and form disinfection by-products (DBPs). DBPs are unwanted from a health point of view, because some are irritating, while others might be carcinogenic. The reduction of anthropogenic pollutants will lead to a reduction in DBPs. This paper investigates the continual release of anthropogenic pollutants by means of controlled sweat experiments in a pool tank during laboratory time-series experiments (LTS experiments) and also during on-site experiments (OS experiments) in a swimming pool. The sweat released during the OS and LTS experiments was very similar. The sweat rate found was 0.1-0.2 L/m(2)/h at water temperatures below 29 °C and increased linearly with increasing water temperatures to 0.8 L/m(2)/h at 35 °C. The continual anthropogenic pollutant release (CAPR) not only consisted of sweat, particles (mainly skin fragments and hair) and micro-organisms, but also sebum (skin lipids) has to be considered. The release of most components can be explained by the composition of sweat. The average release during 30 min of exercise is 250 mg/bather non-purgeable organic carbon (NPOC), 77.3 mg/bather total nitrogen (TN), 37.1 mg/bather urea and 10.1 mg/bather ammonium. The release of NPOC cannot be explained by the composition of sweat and is most probably a result of sebum release. The average release of other components was 1.31 × 10(9) # particles/bather (2-50 μm), 5.2 μg/bather intracellular adenosine triphosphate (cATP) and 9.3 × 10(6) intact cell count/bather (iCC). The pool water temperature was the main parameter to restrain the CAPR. This study showed that a significant amount of the total anthropogenic pollutants release is due to unhygienic behaviour of bathers. PMID:24530546

  6. The Oceanic Sink for Anthropogenic CO2

    SciTech Connect

    Sabine, Chris; Feely, R. A.; Gruber, N.; Key, Robert; Lee, K.; Bullister, J.L.; Wanninkhof, R.; Wong, C. S.; Wallace, D.W.R.; Tilbrook, B.; Millero, F. J.; Peng, T.-H.; Kozyr, Alexander; Ono, Tsueno

    2004-01-01

    Using inorganic carbon measurements from an international survey effort in the 1990s and a tracer-based separation technique, we estimate a global oceanic anthropogenic carbon dioxide (CO2) sink for the period from 1800 to 1994 of 118 19 petagrams of carbon. The oceanic sink accounts for ~48% of the total fossil-fuel and cement-manufacturing emissions, implying that the terrestrial biosphere was a net source of CO2 to the atmosphere of about 39 28 petagrams of carbon for this period. The current fraction of total anthropogenic CO2 emissions stored in the ocean appears to be about one-third of the long-term potential.

  7. The oceanic sink for anthropogenic CO2.

    PubMed

    Sabine, Christopher L; Feely, Richard A; Gruber, Nicolas; Key, Robert M; Lee, Kitack; Bullister, John L; Wanninkhof, Rik; Wong, C S; Wallace, Douglas W R; Tilbrook, Bronte; Millero, Frank J; Peng, Tsung-Hung; Kozyr, Alexander; Ono, Tsueno; Rios, Aida F

    2004-07-16

    Using inorganic carbon measurements from an international survey effort in the 1990s and a tracer-based separation technique, we estimate a global oceanic anthropogenic carbon dioxide (CO2) sink for the period from 1800 to 1994 of 118 +/- 19 petagrams of carbon. The oceanic sink accounts for approximately 48% of the total fossil-fuel and cement-manufacturing emissions, implying that the terrestrial biosphere was a net source of CO2 to the atmosphere of about 39 +/- 28 petagrams of carbon for this period. The current fraction of total anthropogenic CO2 emissions stored in the ocean appears to be about one-third of the long-term potential.

  8. Global analysis of anthropogenic debris ingestion by sea turtles.

    PubMed

    Schuyler, Qamar; Hardesty, Britta Denise; Wilcox, Chris; Townsend, Kathy

    2014-02-01

    Ingestion of marine debris can have lethal and sublethal effects on sea turtles and other wildlife. Although researchers have reported on ingestion of anthropogenic debris by marine turtles and implied incidences of debris ingestion have increased over time, there has not been a global synthesis of the phenomenon since 1985. Thus, we analyzed 37 studies published from 1985 to 2012 that report on data collected from before 1900 through 2011. Specifically, we investigated whether ingestion prevalence has changed over time, what types of debris are most commonly ingested, the geographic distribution of debris ingestion by marine turtles relative to global debris distribution, and which species and life-history stages are most likely to ingest debris. The probability of green (Chelonia mydas) and leatherback turtles (Dermochelys coriacea) ingesting debris increased significantly over time, and plastic was the most commonly ingested debris. Turtles in nearly all regions studied ingest debris, but the probability of ingestion was not related to modeled debris densities. Furthermore, smaller, oceanic-stage turtles were more likely to ingest debris than coastal foragers, whereas carnivorous species were less likely to ingest debris than herbivores or gelatinovores. Our results indicate oceanic leatherback turtles and green turtles are at the greatest risk of both lethal and sublethal effects from ingested marine debris. To reduce this risk, anthropogenic debris must be managed at a global level.

  9. Global analysis of anthropogenic debris ingestion by sea turtles.

    PubMed

    Schuyler, Qamar; Hardesty, Britta Denise; Wilcox, Chris; Townsend, Kathy

    2014-02-01

    Ingestion of marine debris can have lethal and sublethal effects on sea turtles and other wildlife. Although researchers have reported on ingestion of anthropogenic debris by marine turtles and implied incidences of debris ingestion have increased over time, there has not been a global synthesis of the phenomenon since 1985. Thus, we analyzed 37 studies published from 1985 to 2012 that report on data collected from before 1900 through 2011. Specifically, we investigated whether ingestion prevalence has changed over time, what types of debris are most commonly ingested, the geographic distribution of debris ingestion by marine turtles relative to global debris distribution, and which species and life-history stages are most likely to ingest debris. The probability of green (Chelonia mydas) and leatherback turtles (Dermochelys coriacea) ingesting debris increased significantly over time, and plastic was the most commonly ingested debris. Turtles in nearly all regions studied ingest debris, but the probability of ingestion was not related to modeled debris densities. Furthermore, smaller, oceanic-stage turtles were more likely to ingest debris than coastal foragers, whereas carnivorous species were less likely to ingest debris than herbivores or gelatinovores. Our results indicate oceanic leatherback turtles and green turtles are at the greatest risk of both lethal and sublethal effects from ingested marine debris. To reduce this risk, anthropogenic debris must be managed at a global level. PMID:23914794

  10. Transport pathway and depocenter of anthropogenic heavy metals off the Shandong Peninsula, China

    NASA Astrophysics Data System (ADS)

    Xu, Gang; Liu, Jian; Pei, Shaofeng; Gao, Maosheng; Kong, Xianghuai

    2016-10-01

    Surface sediment grain size as well as the spatial distribution, sources and geochemical baseline levels of heavy metals in the south Shandong Peninsula clinoform were analyzed to determine the transport pathway and main depocenter of anthropogenic heavy metals off the peninsula. Results showed that the surface sediments were primarily silt-sized components, and the fine grain matter mainly originated from the Yellow River and rivers around Laizhou Bay. Heavy metals Cu, Pb, Zn, Cr, and Cd were predominantly from natural sources and their spatial distributions were controlled by grain size; conversely, anthropogenic As (concentration above geochemical baseline level 10.9 mg/kg) was principally derived from human activities, and its transportation from the Yellow River and Laizhou Bay was controlled by the Shandong Coastal Current off the Shandong Peninsula. Furthermore, the anthropogenic As was deposited in three main areas, that is, the Yellow River estuary, Laizhou Bay, and south Shandong Peninsula clinoform.

  11. Acid lakes from natural and anthropogenic causes

    SciTech Connect

    Patrick, R.; Binetti, V.P.; Halterman, S.G.

    1981-01-30

    Lakes may be acid because of natural ecological conditions or because of anthropogenic activities. Apparently there has been a recent increase in acidity of many lakes in the northeastern United States. Factors that may be contributing to this increase include the use by utilities of precipitators, sulfur scrubbers, and tall stacks; the use of petroleum; and methods of combustion of fossil fuels.

  12. (Pre-) historic changes in natural and anthropogenic heavy metals deposition inferred from two contrasting Swiss Alpine lakes

    NASA Astrophysics Data System (ADS)

    Thevenon, Florian; Guédron, Stéphane; Chiaradia, Massimo; Loizeau, Jean-Luc; Poté, John

    2011-01-01

    Continuous high-resolution sedimentary record of heavy metals (chromium (Cr), copper (Cu), lead (Pb), zinc (Zn), manganese (Mn), and mercury (Hg)), from lakes Lucerne and Meidsee (Switzerland), provides pollutant deposition history from two contrasting Alpine environments over the last millennia. The distribution of conservative elements (thorium (Th), scandium (Sc) and titanium (Ti)) shows that in absence of human disturbances, the trace element input is primarily controlled by weathering processes (i.e., runoff and erosion). Nonetheless, the enrichment factor (EF) of Pb and Hg (that are measured by independent methods), and the Pb isotopic composition of sediments from the remote lake Meidsee (which are proportionally more enriched in anthropogenic heavy metals), likely detect early mining activities during the Bronze Age. Meanwhile, the deposition of trace elements remains close to the range of natural variations until the strong impact of Roman activities on atmospheric metal emissions. Both sites display simultaneous increases in anthropogenic trace metal deposition during the Greek and Roman Empires (ca 300 BC to AD 400), the Late Middle Ages (ca AD 1400), and the Early Modern Europe (after ca AD 1600). However, the greatest increases in anthropogenic metal pollution are evidenced after the industrial revolution of ca AD 1850, at low and high altitudes. During the twentieth century, industrial releases multiplied by ca 10 times heavy metal fluxes to hydrological systems located on both sides of the Alps. During the last decades, the recent growing contribution of low radiogenic Pb further highlights the contribution of industrial sources with respect to wood and coal burning emissions.

  13. Predicting anthropogenic soils across the Amazonia

    NASA Astrophysics Data System (ADS)

    Mcmichael, C.; Palace, M. W.; Bush, M. B.; Braswell, B. H.; Hagen, S. C.; Silman, M.; Neves, E.; Czarnecki, C.

    2012-12-01

    of area covered by terra preta. Distance to river, locations of bluffs, elevation, and soil fertility were important factors in determining distributions of terra preta, while other environmental variables had less effect. Terra pretas were most likely to be found in central and eastern Amazonia near the confluences of the Amazon River and its major tributaries. Within this general area of higher probability, terra pretas are most likely found atop the bluffs overlooking the rivers as opposed to lying on the floodplain. Interestingly, terra pretas are more probable in areas with less-fertile and more highly weathered soils. Although all three modeling techniques provided similar predictions of terra preta across Amazonia, we suggest that maximum entropy modeling is the best technique to predict anthropogenic soils across the vast Amazonian landscape. The auto-logistic regression corrects for spatial autocorrelation inherent to archaeological surveys, but still requires absence data, which was collected at different times and on different spatial scales than the presence data. The maximum entropy model requires presence only data, accounts for spatial autocorrelation, and is not affected by the differential soil sampling techniques.

  14. Lead Toxicity

    MedlinePlus

    ... homes. • Most people, especially children, who suffer from lead poisoning are exposed through lead-contaminated household dust or ... and six if they are at risk of lead poisoning (see: ). Who can I call to get more ...

  15. Coastal-ocean uptake of anthropogenic carbon

    NASA Astrophysics Data System (ADS)

    Bourgeois, Timothée; Orr, James C.; Resplandy, Laure; Terhaar, Jens; Ethé, Christian; Gehlen, Marion; Bopp, Laurent

    2016-07-01

    Anthropogenic changes in atmosphere-ocean and atmosphere-land CO2 fluxes have been quantified extensively, but few studies have addressed the connection between land and ocean. In this transition zone, the coastal ocean, spatial and temporal data coverage is inadequate to assess its global budget. Thus we use a global ocean biogeochemical model to assess the coastal ocean's global inventory of anthropogenic CO2 and its spatial variability. We used an intermediate resolution, eddying version of the NEMO-PISCES model (ORCA05), varying from 20 to 50 km horizontally, i.e. coarse enough to allow multiple century-scale simulations but finer than coarse-resolution models (˜ 200 km) to better resolve coastal bathymetry and complex coastal currents. Here we define the coastal zone as the continental shelf area, excluding the proximal zone. Evaluation of the simulated air-sea fluxes of total CO2 for 45 coastal regions gave a correlation coefficient R of 0.8 when compared to observation-based estimates. Simulated global uptake of anthropogenic carbon results averaged 2.3 Pg C yr-1 during the years 1993-2012, consistent with previous estimates. Yet only 0.1 Pg C yr-1 of that is absorbed by the global coastal ocean. That represents 4.5 % of the anthropogenic carbon uptake of the global ocean, less than the 7.5 % proportion of coastal-to-global-ocean surface areas. Coastal uptake is weakened due to a bottleneck in offshore transport, which is inadequate to reduce the mean anthropogenic carbon concentration of coastal waters to the mean level found in the open-ocean mixed layer.

  16. Global Climate Responses to Anthropogenic Groundwater Exploitation

    NASA Astrophysics Data System (ADS)

    Zeng, Y.; Xie, Z.

    2015-12-01

    In this study, a groundwater exploitation scheme is incorporated into the earth system model, Community Earth System Model 1.2.0 (CESM1.2.0), which is called CESM1.2_GW, and the climatic responses to anthropogenic groundwater withdrawal are then investigated on global scale. The scheme models anthropogenic groundwater exploitation and consumption, which are then divided into agricultural irrigation, industrial use and domestic use. A group of 41-year ensemble groundwater exploitation simulations with six different initial conditions, and a group of ensemble control simulations without exploitation are conducted using the developed model CESM1.2_GW with water supplies and demands estimated. The results reveal that the groundwater exploitation and water consumption cause drying effects on soil moisture in deep layers and wetting effects in upper layers, along with a rapidly declining groundwater table in Central US, Haihe River Basin in China and Northern India and Pakistan where groundwater extraction are most severe in the world. The atmosphere also responds to anthropogenic groundwater exploitation. Cooling effects on lower troposphere appear in large areas of North China Plain and of Northern India and Pakistan. Increased precipitation occurs in Haihe River Basin due to increased evapotranspiration from irrigation. Decreased precipitation occurs in Northern India because water vapor here is taken away by monsoon anomalies induced by anthropogenic alteration of groundwater. The local reducing effects of anthropogenic groundwater exploitation on total terrestrial water storage evinces that water resource is unsustainable with the current high exploitation rate. Therefore, a balance between slow groundwater withdrawal and rapid human economic development must be achieved to maintain a sustainable water resource, especially in over-exploitation regions such as Central US, Northern China, India and Pakistan.

  17. Chinese mineral dust and anthropogenic aerosol inter-continental transport: a Greenland perspective

    NASA Astrophysics Data System (ADS)

    Bory, A.; Abouchami, W.; Galer, S.; Svensson, A.; Biscaye, P.

    2012-04-01

    Impurities contained in snow and ice layers in Greenland provide a record of the history of atmospheric dustiness and pollution in the Northern Hemisphere. The source of the particles deposited onto the ice cap may be investigated using specific intrinsic tracers. Provenance discrimination may then provide valuable constraints for the validation of atmospheric transport models as well as for the monitoring of natural and anthropogenic aerosols emissions at a global scale. Clay mineralogy combined with the strontium and neodymium isotope composition of the insoluble particles extracted from recent snow deposits at NorthGRIP (75.1°N, 042.3°W), for instance, enabled us to demonstrate that the Taklimakan desert of North-western China was the main source of mineral dust reaching central Greenland at present [Bory et al., EPSL, 2002 ; GRL, 2003a]. Here we report the lead isotopic signature of these snow-pit samples, covering the 1989-1995 and 1998-2001 time periods. Unradiogenic lead isotopic composition of our Greenland samples, compared to Asian dust isotopic fingerprints, implies that most of the insoluble lead reaching the ice cap is of anthropogenic origin. Lead isotopes reveal likely contributions from European/Canadian and, to a lesser extent, US sources, as well as a marked overprinted signature typical of Chinese anthropogenic lead sources. The relative contribution of the latter appears to have been increasing steadily over the last decade of the 20th century. Quantitative estimates suggest that, in addition to providing most of the dust, China may have already become the most important supplier of anthropogenic lead deposited in Greenland by the turn of the 20th to the 21st century. The close timing between dust and anthropogenic particles deposition onto the ice cap provides new insights for our understanding of Chinese aerosols transport to Greenland.

  18. Anthropogenic disturbances jeopardize biodiversity conservation within tropical rainforest reserves.

    PubMed

    Martínez-Ramos, Miguel; Ortiz-Rodríguez, Iván A; Piñero, Daniel; Dirzo, Rodolfo; Sarukhán, José

    2016-05-10

    Anthropogenic disturbances affecting tropical forest reserves have been documented, but their ecological long-term cumulative effects are poorly understood. Habitat fragmentation and defaunation are two major anthropogenic threats to the integrity of tropical reserves. Based on a long-term (four decades) study, we document how these disturbances synergistically disrupt ecological processes and imperil biodiversity conservation and ecosystem functioning at Los Tuxtlas, the northernmost tropical rainforest reserve in the Americas. Deforestation around this reserve has reduced the reserve to a medium-sized fragment (640 ha), leading to an increased frequency of canopy-gap formation. In addition, hunting and habitat loss have caused the decline or local extinction of medium and large herbivores. Combining empirical, experimental, and modeling approaches, we support the hypothesis that such disturbances produced a demographic explosion of the long-lived (≈120 y old, maximum height of 7 m) understory palm Astrocaryum mexicanum, whose population has increased from 1,243-4,058 adult individuals per hectare in only 39 y (annual growth rate of ca 3%). Faster gap formation increased understory light availability, enhancing seed production and the growth of immature palms, whereas release from mammalian herbivory and trampling increased survival of seedlings and juveniles. In turn, the palm's demographic explosion was followed by a reduction of tree species diversity, changing forest composition, altering the relative contribution of trees to forest biomass, and disrupting litterfall dynamics. We highlight how indirect anthropogenic disturbances (e.g., palm proliferation) on otherwise protected areas threaten tropical conservation, a phenomenon that is currently eroding the planet's richest repositories of biodiversity.

  19. Climate Response of Direct Radiative Forcing of Anthropogenic Black Carbon

    NASA Technical Reports Server (NTRS)

    Chung, Serena H.; Seinfeld,John H.

    2008-01-01

    The equilibrium climate effect of direct radiative forcing of anthropogenic black carbon (BC) is examined by 100-year simulations in the Goddard Institute for Space Studies General Circulation Model II-prime coupled to a mixed-layer ocean model. Anthropogenic BC is predicted to raise globally and annually averaged equilibrium surface air temperature by 0.20 K if BC is assumed to be externally mixed. The predicted increase is significantly greater in the Northern Hemisphere (0.29 K) than in the Southern Hemisphere (0.11 K). If BC is assumed to be internally mixed with the present day level of sulfate aerosol, the predicted annual mean surface temperature increase rises to 0.37 K globally, 0.54 K for the Northern Hemisphere, and 0.20 K for the Southern Hemisphere. The climate sensitivity of BC direct radiative forcing is calculated to be 0.6 K W (sup -1) square meters, which is about 70% of that of CO2, independent of the assumption of BC mixing state. The largest surface temperature response occurs over the northern high latitudes during winter and early spring. In the tropics and midlatitudes, the largest temperature increase is predicted to occur in the upper troposphere. Direct radiative forcing of anthropogenic BC is also predicted to lead to a change of precipitation patterns in the tropics; precipitation is predicted to increase between 0 and 20 N and decrease between 0 and 20 S, shifting the intertropical convergence zone northward. If BC is assumed to be internally mixed with sulfate instead of externally mixed, the change in precipitation pattern is enhanced. The change in precipitation pattern is not predicted to alter the global burden of BC significantly because the change occurs predominantly in regions removed from BC sources.

  20. Filtering ionosphere parameters to detect trends linked to anthropogenic effects

    NASA Astrophysics Data System (ADS)

    Elias, Ana G.

    2014-12-01

    The great concern about the global warming observed in the troposphere has generated a large interest in the study of long-term trends in the ionosphere since the early 1990s, which has now become a significant topic in global change investigations. Some research works link ionosphere trends to anthropogenic sources such as the increase in greenhouse gas concentration, and others to natural causes such as solar and geomagnetic activity long-term changes, and secular variations in the Earth's main magnetic field. In all the cases, in order to analyze ionospheric trends, solar activity effect must be filtered out first since around 90% of ionosphere parameter variance is due to solar variations. The filtering process can generate `spurious' trends in the filtered data series which may lead to erroneous conclusions. foF2 data series which include solar cycle 23 are analyzed in the present work in order to detect the effect of different filtering procedures on the determination of long-term trends. In particular, solar cycle 23 seems to have had an extreme ultraviolet (EUV) emission greater than that deduced from traditional solar EUV proxies during the maximum epoch and lower during the minimum epoch. When solar activity is filtered assessing the residuals of a linear regression between foF2 and Rz, or between foF2 and F10.7, this fact may bias trend values especially because it is at the end of the time series. The length of the period considered for trend assessment, the saturation and hysteresis effect of some ionosphere parameters, and the solar EUV proxy used are also considered in this study in order to quantify a possible spurious trend that may result as a by-product of a filtering process. Since trends expected as a consequence of anthropogenic effects are relatively small, these spurious effects may surely mask, or enhance, trends expected from anthropogenic origins.

  1. The sea surface microlayer: Biology, chemistry and anthropogenic enrichment

    NASA Astrophysics Data System (ADS)

    Hardy, J. T.

    Recent studies increasingly point to the interface between the world's atmosphere and hydrosphere (the sea-surface microlayer) as an important biological habitat and a collection point for anthropogenic materials. Newly developed sampling techniques collect different qualitative and quantitative fractions of the upper sea surface from depths of less than one micron to several centimeters. The microlayer provides a habitat for a biota, including the larvae of many commercial fishery species, which are often highly enriched in density compared to subsurface water only a few cm below. Common enrichments for bacterioneuston, phytoneuston, and zooneuston are 10 2-10 4, 1-10 2, and 1-10, respectively. The trophic relationships or integrated functioning of these neustonic communities have not been examined. Surface tension forces provide a physically stable microlayer, but one which is subjected to greater environmental and climatic variation than the water column. A number of poorly understood physical processes control the movement and flux of materials within and through the microlayer. The microlayer is generally coated with a natural organic film of lipid and fatty acid material overlying a polysaccharide protein complex. The microlayer serves as both a source and a sink for materials in the atmosphere and the water column. Among these materials are large quantities of anthropogenic substances which frequently occur at concentrations 10 2-10 4 greater than these in the water column. These include plastics, tar lumps, polyaromatic hydrocarbons, chlorrinated hydrocarbons, and potentially toxic metals, such as, lead, copper, zinc, and nickel. How the unique processes occurring in the microlayer affect the fate of anthropogenic substances is not yet clear. Many important questions remain to be examined.

  2. Bacterioplankton Dynamics within a Large Anthropogenically Impacted Urban Estuary.

    PubMed

    Jeffries, Thomas C; Schmitz Fontes, Maria L; Harrison, Daniel P; Van-Dongen-Vogels, Virginie; Eyre, Bradley D; Ralph, Peter J; Seymour, Justin R

    2015-01-01

    The abundant and diverse microorganisms that inhabit aquatic systems are both determinants and indicators of aquatic health, providing essential ecosystem services such as nutrient cycling but also causing harmful blooms and disease in impacted habitats. Estuaries are among the most urbanized coastal ecosystems and as a consequence experience substantial environmental pressures, providing ideal systems to study the influence of anthropogenic inputs on microbial ecology. Here we use the highly urbanized Sydney Harbor, Australia, as a model system to investigate shifts in microbial community composition and function along natural and anthopogenic physicochemical gradients, driven by stormwater inflows, tidal flushing and the input of contaminants and both naturally and anthropogenically derived nutrients. Using a combination of amplicon sequencing of the 16S rRNA gene and shotgun metagenomics, we observed strong patterns in microbial biogeography across the estuary during two periods: one of high and another of low rainfall. These patterns were driven by shifts in nutrient concentration and dissolved oxygen leading to a partitioning of microbial community composition in different areas of the harbor with different nutrient regimes. Patterns in bacterial composition were related to shifts in the abundance of Rhodobacteraceae, Flavobacteriaceae, Microbacteriaceae, Halomonadaceae, Acidomicrobiales, and Synechococcus, coupled to an enrichment of total microbial metabolic pathways including phosphorus and nitrogen metabolism, sulfate reduction, virulence, and the degradation of hydrocarbons. Additionally, community beta-diversity was partitioned between the two sampling periods. This potentially reflected the influence of shifting allochtonous nutrient inputs on microbial communities and highlighted the temporally dynamic nature of the system. Combined, our results provide insights into the simultaneous influence of natural and anthropogenic drivers on the structure and

  3. Bacterioplankton Dynamics within a Large Anthropogenically Impacted Urban Estuary

    PubMed Central

    Jeffries, Thomas C.; Schmitz Fontes, Maria L.; Harrison, Daniel P.; Van-Dongen-Vogels, Virginie; Eyre, Bradley D.; Ralph, Peter J.; Seymour, Justin R.

    2016-01-01

    The abundant and diverse microorganisms that inhabit aquatic systems are both determinants and indicators of aquatic health, providing essential ecosystem services such as nutrient cycling but also causing harmful blooms and disease in impacted habitats. Estuaries are among the most urbanized coastal ecosystems and as a consequence experience substantial environmental pressures, providing ideal systems to study the influence of anthropogenic inputs on microbial ecology. Here we use the highly urbanized Sydney Harbor, Australia, as a model system to investigate shifts in microbial community composition and function along natural and anthopogenic physicochemical gradients, driven by stormwater inflows, tidal flushing and the input of contaminants and both naturally and anthropogenically derived nutrients. Using a combination of amplicon sequencing of the 16S rRNA gene and shotgun metagenomics, we observed strong patterns in microbial biogeography across the estuary during two periods: one of high and another of low rainfall. These patterns were driven by shifts in nutrient concentration and dissolved oxygen leading to a partitioning of microbial community composition in different areas of the harbor with different nutrient regimes. Patterns in bacterial composition were related to shifts in the abundance of Rhodobacteraceae, Flavobacteriaceae, Microbacteriaceae, Halomonadaceae, Acidomicrobiales, and Synechococcus, coupled to an enrichment of total microbial metabolic pathways including phosphorus and nitrogen metabolism, sulfate reduction, virulence, and the degradation of hydrocarbons. Additionally, community beta-diversity was partitioned between the two sampling periods. This potentially reflected the influence of shifting allochtonous nutrient inputs on microbial communities and highlighted the temporally dynamic nature of the system. Combined, our results provide insights into the simultaneous influence of natural and anthropogenic drivers on the structure and

  4. Anthropogenic heat flux estimation from space: first results

    NASA Astrophysics Data System (ADS)

    Chrysoulakis, Nektarios; Heldens, Wieke; Gastellu-Etchegorry, Jean-Philippe; Grimmond, Sue; Feigenwinter, Christian; Lindberg, Fredrik; Del Frate, Fabio; Klostermann, Judith; Mitraka, Zina; Esch, Thomas; Albitar, Ahmad; Gabey, Andrew; Parlow, Eberhard; Olofson, Frans

    2016-04-01

    While Earth Observation (EO) has made significant advances in the study of urban areas, there are several unanswered science and policy questions to which it could contribute. To this aim the recently launched Horizon 2020 project URBANFLUXES (URBan ANthrpogenic heat FLUX from Earth observation Satellites) investigates the potential of EO to retrieve anthropogenic heat flux, as a key component in the urban energy budget. The anthropogenic heat flux is the heat flux resulting from vehicular emissions, space heating and cooling of buildings, industrial processing and the metabolic heat release by people. Optical, thermal and SAR data from existing satellite sensors are used to improve the accuracy of the radiation balance spatial distribution calculation, using also in-situ reflectance measurements of urban materials are for calibration. EO-based methods are developed for estimating turbulent sensible and latent heat fluxes, as well as urban heat storage flux and anthropogenic heat flux spatial patterns at city scale and local scale by employing an energy budget closure approach. Independent methods and models are engaged to evaluate the derived products and statistical analyses provide uncertainty measures as well. Ultimate goal of the URBANFLUXES is to develop a highly automated method for estimating urban energy budget components to use with Copernicus Sentinel data, enabling its integration into applications and operational services. Thus, URBANFLUXES prepares the ground for further innovative exploitation of European space data in scientific activities (i.e. Earth system modelling and climate change studies in cities) and future and emerging applications (i.e. sustainable urban planning) by exploiting the improved data quality, coverage and revisit times of the Copernicus data. The URBANFLUXES products will therefore have the potential to support both sustainable planning strategies to improve the quality of life in cities, as well as Earth system models to

  5. Lead Poisoning

    MedlinePlus

    ... can be found in all parts of our environment. Much of it comes from human activities such as mining and manufacturing. Lead used to be in paint; older houses may still have lead paint. You could be exposed to lead by Eating food or drinking water that contains lead. Water pipes in older homes ...

  6. Lead poisoning

    SciTech Connect

    Rekus, J.F.

    1992-08-01

    Construction workers who weld, cut or blast structural steel coated with lead-based paint are at significant risk of lead poisoning. Although technology to control these exposures may not have existed when the lead standard was promulgated, it is available today. Employers who do not take steps to protect their employees from lead exposure may be cited and fined severely for their failure.

  7. Measurement of the distributions of event-by-event flow harmonics in lead-lead collisions at = 2.76 TeV with the ATLAS detector at the LHC

    NASA Astrophysics Data System (ADS)

    Aad, G.; Abajyan, T.; Abbott, B.; Abdallah, J.; Abdel Khalek, S.; Abdelalim, A. A.; Abdinov, O.; Aben, R.; Abi, B.; Abolins, M.; AbouZeid, O. S.; Abramowicz, H.; Abreu, H.; Abulaiti, Y.; Acharya, B. S.; Adamczyk, L.; Adams, D. L.; Addy, T. N.; Adelman, J.; Adomeit, S.; Adye, T.; Aefsky, S.; Aguilar-Saavedra, J. A.; Agustoni, M.; Ahlen, S. P.; Ahles, F.; Ahmad, A.; Ahsan, M.; Aielli, G.; Åkesson, T. P. A.; Akimoto, G.; Akimov, A. V.; Alam, M. A.; Albert, J.; Albrand, S.; Alconada Verzini, M. J.; Aleksa, M.; Aleksandrov, I. N.; Alessandria, F.; Alexa, C.; Alexander, G.; Alexandre, G.; Alexopoulos, T.; Alhroob, M.; Aliev, M.; Alimonti, G.; Alison, J.; Allbrooke, B. M. M.; Allison, L. J.; Allport, P. P.; Allwood-Spiers, S. E.; Almond, J.; Aloisio, A.; Alon, R.; Alonso, A.; Alonso, F.; Altheimer, A.; Alvarez Gonzalez, B.; Alviggi, M. G.; Amako, K.; Amaral Coutinho, Y.; Amelung, C.; Ammosov, V. V.; Amor Dos Santos, S. P.; Amorim, A.; Amoroso, S.; Amram, N.; Anastopoulos, C.; Ancu, L. S.; Andari, N.; Andeen, T.; Anders, C. F.; Anders, G.; Anderson, K. J.; Andreazza, A.; Andrei, V.; Anduaga, X. S.; Angelidakis, S.; Anger, P.; Angerami, A.; Anghinolfi, F.; Anisenkov, A.; Anjos, N.; Annovi, A.; Antonaki, A.; Antonelli, M.; Antonov, A.; Antos, J.; Anulli, F.; Aoki, M.; Aperio Bella, L.; Apolle, R.; Arabidze, G.; Aracena, I.; Arai, Y.; Arce, A. T. H.; Arfaoui, S.; Arguin, J.-F.; Argyropoulos, S.; Arik, E.; Arik, M.; Armbruster, A. J.; Arnaez, O.; Arnal, V.; Artamonov, A.; Artoni, G.; Arutinov, D.; Asai, S.; Asbah, N.; Ask, S.; Åsman, B.; Asquith, L.; Assamagan, K.; Astalos, R.; Astbury, A.; Atkinson, M.; Auerbach, B.; Auge, E.; Augsten, K.; Aurousseau, M.; Avolio, G.; Axen, D.; Azuelos, G.; Azuma, Y.; Baak, M. A.; Bacci, C.; Bach, A. M.; Bachacou, H.; Bachas, K.; Backes, M.; Backhaus, M.; Backus Mayes, J.; Badescu, E.; Bagiacchi, P.; Bagnaia, P.; Bai, Y.; Bailey, D. C.; Bain, T.; Baines, J. T.; Baker, O. K.; Baker, S.; Balek, P.; Balli, F.; Banas, E.; Banerjee, P.; Banerjee, Sw.; Banfi, D.; Bangert, A.; Bansal, V.; Bansil, H. S.; Barak, L.; Baranov, S. P.; Barber, T.; Barberio, E. L.; Barberis, D.; Barbero, M.; Bardin, D. Y.; Barillari, T.; Barisonzi, M.; Barklow, T.; Barlow, N.; Barnett, B. M.; Barnett, R. M.; Baroncelli, A.; Barone, G.; Barr, A. J.; Barreiro, F.; Barreiro Guimarães da Costa, J.; Bartoldus, R.; Barton, A. E.; Bartsch, V.; Basye, A.; Bates, R. L.; Batkova, L.; Batley, J. R.; Battaglia, A.; Battistin, M.; Bauer, F.; Bawa, H. S.; Beale, S.; Beau, T.; Beauchemin, P. H.; Beccherle, R.; Bechtle, P.; Beck, H. P.; Becker, K.; Becker, S.; Beckingham, M.; Becks, K. H.; Beddall, A. J.; Beddall, A.; Bedikian, S.; Bednyakov, V. A.; Bee, C. P.; Beemster, L. J.; Beermann, T. A.; Begel, M.; Belanger-Champagne, C.; Bell, P. J.; Bell, W. 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B.; Sipica, V.; Siragusa, G.; Sircar, A.; Sisakyan, A. N.; Sivoklokov, S. Yu.; Sjölin, J.; Sjursen, T. B.; Skinnari, L. A.; Skottowe, H. P.; Skovpen, K.; Skubic, P.; Slater, M.; Slavicek, T.; Sliwa, K.; Smakhtin, V.; Smart, B. H.; Smestad, L.; Smirnov, S. Yu.; Smirnov, Y.; Smirnova, L. N.; Smirnova, O.; Smith, K. M.; Smizanska, M.; Smolek, K.; Snesarev, A. A.; Snidero, G.; Snow, J.; Snyder, S.; Sobie, R.; Sodomka, J.; Soffer, A.; Soh, D. A.; Solans, C. A.; Solar, M.; Solc, J.; Soldatov, E. Yu.; Soldevila, U.; Camillocci, E. Solfaroli; Solodkov, A. A.; Solovyanov, O. V.; Solovyev, V.; Soni, N.; Sood, A.; Sopko, V.; Sopko, B.; Sosebee, M.; Soualah, R.; Soueid, P.; Soukharev, A.; South, D.; Spagnolo, S.; Spanò, F.; Spighi, R.; Spigo, G.; Spiwoks, R.; Spousta, M.; Spreitzer, T.; Spurlock, B.; Denis, R. D. St.; Stahlman, J.; Stamen, R.; Stanecka, E.; Stanek, R. W.; Stanescu, C.; Stanescu-Bellu, M.; Stanitzki, M. M.; Stapnes, S.; Starchenko, E. A.; Stark, J.; Staroba, P.; Starovoitov, P.; Staszewski, R.; Staude, A.; Stavina, P.; Steele, G.; Steinbach, P.; Steinberg, P.; Stekl, I.; Stelzer, B.; Stelzer, H. J.; Stelzer-Chilton, O.; Stenzel, H.; Stern, S.; Stewart, G. A.; Stillings, J. A.; Stockton, M. C.; Stoebe, M.; Stoerig, K.; Stoicea, G.; Stonjek, S.; Stradling, A. R.; Straessner, A.; Strandberg, J.; Strandberg, S.; Strandlie, A.; Strang, M.; Strauss, E.; Strauss, M.; Strizenec, P.; Ströhmer, R.; Strom, D. M.; Strong, J. A.; Stroynowski, R.; Stugu, B.; Stumer, I.; Stupak, J.; Sturm, P.; Styles, N. A.; Su, D.; Subramania, HS.; Subramaniam, R.; Succurro, A.; Sugaya, Y.; Suhr, C.; Suk, M.; Sulin, V. V.; Sultansoy, S.; Sumida, T.; Sun, X.; Sundermann, J. E.; Suruliz, K.; Susinno, G.; Sutton, M. R.; Suzuki, Y.; Suzuki, Y.; Svatos, M.; Swedish, S.; Swiatlowski, M.; Sykora, I.; Sykora, T.; Ta, D.; Tackmann, K.; Taffard, A.; Tafirout, R.; Taiblum, N.; Takahashi, Y.; Takai, H.; Takashima, R.; Takeda, H.; Takeshita, T.; Takubo, Y.; Talby, M.; Talyshev, A.; Tam, J. Y. C.; Tamsett, M. C.; Tan, K. G.; Tanaka, J.; Tanaka, R.; Tanaka, S.; Tanaka, S.; Tanasijczuk, A. J.; Tani, K.; Tannoury, N.; Tapprogge, S.; Tarem, S.; Tarrade, F.; Tartarelli, G. F.; Tas, P.; Tasevsky, M.; Tashiro, T.; Tassi, E.; Tayalati, Y.; Taylor, C.; Taylor, F. E.; Taylor, G. N.; Taylor, W.; Teinturier, M.; Teischinger, F. A.; Castanheira, M. Teixeira Dias; Teixeira-Dias, P.; Temming, K. K.; Ten Kate, H.; Teng, P. K.; Terada, S.; Terashi, K.; Terron, J.; Testa, M.; Teuscher, R. J.; Therhaag, J.; Theveneaux-Pelzer, T.; Thoma, S.; Thomas, J. P.; Thompson, E. N.; Thompson, P. D.; Thompson, P. D.; Thompson, A. S.; Thomsen, L. A.; Thomson, E.; Thomson, M.; Thong, W. M.; Thun, R. P.; Tian, F.; Tibbetts, M. J.; Tic, T.; Tikhomirov, V. O.; Tikhonov, Y. A.; Timoshenko, S.; Tiouchichine, E.; Tipton, P.; Tisserant, S.; Todorov, T.; Todorova-Nova, S.; Toggerson, B.; Tojo, J.; Tokár, S.; Tokushuku, K.; Tollefson, K.; Tomlinson, L.; Tomoto, M.; Tompkins, L.; Toms, K.; Tonoyan, A.; Topfel, C.; Topilin, N. D.; Torrence, E.; Torres, H.; Torró Pastor, E.; Toth, J.; Touchard, F.; Tovey, D. R.; Tran, H. L.; Trefzger, T.; Tremblet, L.; Tricoli, A.; Trigger, I. M.; Trincaz-Duvoid, S.; Tripiana, M. F.; Triplett, N.; Trischuk, W.; Trocmé, B.; Troncon, C.; Trottier-McDonald, M.; Trovatelli, M.; True, P.; Trzebinski, M.; Trzupek, A.; Tsarouchas, C.; Tseng, J. C.-L.; Tsiakiris, M.; Tsiareshka, P. V.; Tsionou, D.; Tsipolitis, G.; Tsiskaridze, S.; Tsiskaridze, V.; Tskhadadze, E. G.; Tsukerman, I. I.; Tsulaia, V.; Tsung, J.-W.; Tsuno, S.; Tsybychev, D.; Tua, A.; Tudorache, A.; Tudorache, V.; Tuggle, J. M.; Tuna, A. N.; Turala, M.; Turecek, D.; Cakir, I. Turk; Turra, R.; Tuts, P. M.; Tykhonov, A.; Tylmad, M.; Tyndel, M.; Uchida, K.; Ueda, I.; Ueno, R.; Ughetto, M.; Ugland, M.; Uhlenbrock, M.; Ukegawa, F.; Unal, G.; Undrus, A.; Unel, G.; Ungaro, F. C.; Unno, Y.; Urbaniec, D.; Urquijo, P.; Usai, G.; Vacavant, L.; Vacek, V.; Vachon, B.; Vahsen, S.; Valencic, N.; Valentinetti, S.; Valero, A.; Valery, L.; Valkar, S.; Gallego, E. Valladolid; Vallecorsa, S.; Ferrer, J. A. Valls; Van Berg, R.; Van Der Deijl, P. C.; van der Geer, R.; van der Graaf, H.; Van Der Leeuw, R.; van der Ster, D.; van Eldik, N.; van Gemmeren, P.; Van Nieuwkoop, J.; van Vulpen, I.; Vanadia, M.; Vandelli, W.; Vaniachine, A.; Vankov, P.; Vannucci, F.; Vari, R.; Varnes, E. W.; Varol, T.; Varouchas, D.; Vartapetian, A.; Varvell, K. E.; Vassilakopoulos, V. I.; Vazeille, F.; Vazquez Schroeder, T.; Veloso, F.; Veneziano, S.; Ventura, A.; Ventura, D.; Venturi, M.; Venturi, N.; Vercesi, V.; Verducci, M.; Verkerke, W.; Vermeulen, J. C.; Vest, A.; Vetterli, M. C.; Vichou, I.; Vickey, T.; Boeriu, O. E. Vickey; Viehhauser, G. H. A.; Viel, S.; Villa, M.; Perez, M. Villaplana; Vilucchi, E.; Vincter, M. G.; Vinogradov, V. B.; Virzi, J.; Vitells, O.; Viti, M.; Vivarelli, I.; Vives Vaque, F.; Vlachos, S.; Vladoiu, D.; Vlasak, M.; Vogel, A.; Vokac, P.; Volpi, G.; Volpi, M.; Volpini, G.; von der Schmitt, H.; von Radziewski, H.; von Toerne, E.; Vorobel, V.; Vos, M.; Voss, R.; Vossebeld, J. H.; Vranjes, N.; Milosavljevic, M. Vranjes; Vrba, V.; Vreeswijk, M.; Anh, T. Vu; Vuillermet, R.; Vukotic, I.; Vykydal, Z.; Wagner, W.; Wagner, P.; Wahrmund, S.; Wakabayashi, J.; Walch, S.; Walder, J.; Walker, R.; Walkowiak, W.; Wall, R.; Waller, P.; Walsh, B.; Wang, C.; Wang, H.; Wang, H.; Wang, J.; Wang, J.; Wang, K.; Wang, R.; Wang, S. M.; Wang, T.; Wang, X.; Warburton, A.; Ward, C. P.; Wardrope, D. R.; Warsinsky, M.; Washbrook, A.; Wasicki, C.; Watanabe, I.; Watkins, P. M.; Watson, A. T.; Watson, I. J.; Watson, M. F.; Watts, G.; Watts, S.; Waugh, A. T.; Waugh, B. M.; Weber, M. S.; Webster, J. S.; Weidberg, A. R.; Weigell, P.; Weingarten, J.; Weiser, C.; Wells, P. S.; Wenaus, T.; Wendland, D.; Weng, Z.; Wengler, T.; Wenig, S.; Wermes, N.; Werner, M.; Werner, P.; Werth, M.; Wessels, M.; Wetter, J.; Whalen, K.; White, A.; White, M. J.; White, R.; White, S.; Whitehead, S. R.; Whiteson, D.; Whittington, D.; Wicke, D.; Wickens, F. J.; Wiedenmann, W.; Wielers, M.; Wienemann, P.; Wiglesworth, C.; Wiik-Fuchs, L. A. M.; Wijeratne, P. A.; Wildauer, A.; Wildt, M. A.; Wilhelm, I.; Wilkens, H. G.; Will, J. Z.; Williams, E.; Williams, H. H.; Williams, S.; Willis, W.; Willocq, S.; Wilson, J. A.; Wilson, A.; Wingerter-Seez, I.; Winkelmann, S.; Winklmeier, F.; Wittgen, M.; Wittig, T.; Wittkowski, J.; Wollstadt, S. J.; Wolter, M. W.; Wolters, H.; Wong, W. C.; Wooden, G.; Wosiek, B. K.; Wotschack, J.; Woudstra, M. J.; Wozniak, K. W.; Wraight, K.; Wright, M.; Wrona, B.; Wu, S. L.; Wu, X.; Wu, Y.; Wulf, E.; Wynne, B. M.; Xella, S.; Xiao, M.; Xie, S.; Xu, C.; Xu, D.; Xu, L.; Yabsley, B.; Yacoob, S.; Yamada, M.; Yamaguchi, H.; Yamaguchi, Y.; Yamamoto, A.; Yamamoto, K.; Yamamoto, S.; Yamamura, T.; Yamanaka, T.; Yamauchi, K.; Yamazaki, T.; Yamazaki, Y.; Yan, Z.; Yang, H.; Yang, H.; Yang, U. K.; Yang, Y.; Yang, Z.; Yanush, S.; Yao, L.; Yasu, Y.; Yatsenko, E.; Wong, K. H. Yau; Ye, J.; Ye, S.; Yen, A. L.; Yildirim, E.; Yilmaz, M.; Yoosoofmiya, R.; Yorita, K.; Yoshida, R.; Yoshihara, K.; Young, C.; Young, C. J. S.; Youssef, S.; Yu, D.; Yu, D. R.; Yu, J.; Yu, J.; Yuan, L.; Yurkewicz, A.; Zabinski, B.; Zaidan, R.; Zaitsev, A. M.; Zambito, S.; Zanello, L.; Zanzi, D.; Zaytsev, A.; Zeitnitz, C.; Zeman, M.; Zemla, A.; Zenin, O.; Ženiš, T.; Zerwas, D.; della Porta, G. Zevi; Zhang, D.; Zhang, H.; Zhang, J.; Zhang, L.; Zhang, X.; Zhang, Z.; Zhao, Z.; Zhemchugov, A.; Zhong, J.; Zhou, B.; Zhou, N.; Zhou, Y.; Zhu, C. G.; Zhu, H.; Zhu, J.; Zhu, Y.; Zhuang, X.; Zibell, A.; Zieminska, D.; Zimin, N. I.; Zimmermann, C.; Zimmermann, R.; Zimmermann, S.; Zimmermann, S.; Zinonos, Z.; Ziolkowski, M.; Zitoun, R.; Živković, L.; Zmouchko, V. V.; Zobernig, G.; Zoccoli, A.; zur Nedden, M.; Zutshi, V.; Zwalinski, L.

    2013-11-01

    The distributions of event-by-event harmonic flow coefficients v n for n = 2- 4 are measured in = 2 .76 TeV Pb + Pb collisions using the ATLAS detector at the LHC. The measurements are performed using charged particles with transverse momentum p T > 0 .5 GeV and in the pseudorapidity range | η| < 2 .5 in a dataset of approximately 7 μb-1 recorded in 2010. The shapes of the v n distributions suggest that the associated flow vectors are described by a two-dimensional Gaussian function in central collisions for v 2 and over most of the measured centrality range for v 3 and v 4. Significant deviations from this function are observed for v 2 in mid-central and peripheral collisions, and a small deviation is observed for v 3 in mid-central collisions. In order to be sensitive to these deviations, it is shown that the commonly used multi-particle cumulants, involving four particles or more, need to be measured with a precision better than a few percent. The v n distributions are also measured independently for charged particles with 0 .5 < p T < 1 GeV and p T > 1 GeV. When these distributions are rescaled to the same mean values, the adjusted shapes are found to be nearly the same for these two p T ranges. The v n distributions are compared with the eccentricity distributions from two models for the initial collision geometry: a Glauber model and a model that includes corrections to the initial geometry due to gluon saturation effects. Both models fail to describe the experimental data consistently over most of the measured centrality range. [Figure not available: see fulltext.

  8. Sources of anthropogenic radionuclides in the environment: a review.

    PubMed

    Hu, Qin-Hong; Weng, Jian-Qing; Wang, Jin-Sheng

    2010-06-01

    Studies of radionuclides in the environment have entered a new era with the renaissance of nuclear energy and associated fuel reprocessing, geological disposal of high-level nuclear wastes, and concerns about national security with respect to nuclear non-proliferation. This work presents an overview on sources of anthropogenic radionuclides in the environment, as well as a brief discussion of salient geochemical behavior of important radionuclides. We first discuss the following major anthropogenic sources and current developments that have lead, or could potentially contribute, to the radionuclide contamination of the environment: (1) nuclear weapons program; (2) nuclear weapons testing; (3) nuclear power plants; (4) uranium mining and milling; (5) commercial fuel reprocessing; (6) geological repository of high-level nuclear wastes that include radionuclides might be released in the future, and (7) nuclear accidents. Then, we briefly summarize the inventory of radionuclides (99)Tc and (129)I, as well as geochemical behavior for radionuclides (99)Tc, (129)I, and (237)Np, because of their complex geochemical behavior, long half-lives, and presumably high mobility in the environment; biogeochemical cycling and environment risk assessment must take into account speciation of these redox-sensitive radionuclides. PMID:18819734

  9. Can anthropogenic aerosol concentrations effect the snowfall rate?

    NASA Astrophysics Data System (ADS)

    Lohmann, U.; Zhang, J.; Pi, J.

    2003-04-01

    The mesoscale model GESIMA is used to simulate microphysical properties of Arctic clouds and their effect on radiation. Different case studies during the FIRE.ACE/SHEBA project show that GESIMA is able to simulate the cloud boundaries, ice and liquid water content and effective radii in good agreement with observations. For two different aerosol scenarios, the simulation results show that the anthropogenic aerosol can alter microphysical properties of Arctic clouds, and consequently modify surface precipitation. Borys et al. (2000) proposed that anthropogenically-induced decreases in cloud droplet size inhibit the riming process. On the contrary, we find that the accretion of snow crystals with cloud droplets is increased in the polluted cloud due to its higher cloud droplet number concentration. Instead the autoconversion rate of cloud droplets and accretion of drizzle by snow decreases caused by the shut-down of the collision-coalescence process in the polluted cloud. The amount of precipitation reaching the surface as snow depends crucially on the crystal shape. If aggregates are assumed, then a 10-fold increase in aerosol concentration leads to an increase in accumulated snow by 40% after 7 hours of simulation whereas the snow amount decreases by 30% when planar crystals are assumed because of the larger accretion efficiency of snow crystals with cloud droplets in case of aggregates. We will also perform climate model simulations to estimate the importance of this effect globally.

  10. Atmospheric black carbon in the Russian Arctic: anthropogenic inputs in comparison with average or extremal wood fires' ones

    NASA Astrophysics Data System (ADS)

    Vinogradova, Anna A.; Smirnov, Nikolay S.; Korotkov, Vladimir N.

    2016-04-01

    Model estimates of atmospheric black carbon concentrations were made for different points of the Russian Arctic. Anthropogenic BC emissions and wood fires' ones were calculated from Russian official statistics for the 2000s. We used the data of Ministry of Natural Resources and Environment of RF on anthropogenic air emissions of pollution in Russian cities and regions [1], as well as the data of Federal Forestry Agency of RF (Rosleshoz) [2] on wood fires. We considered the area within (50-72)N and (20-180)E, which covers about 94% of the Russian territory, where both anthropogenic and fire BC emissions have been arranged through grid cells (1×1) deg. Anthropogenic BC emissions are estimated as annual values based on the data for 54 regions and more than 100 cities. Total emission is estimated as (220 ± 30) Gg BC in 2010 [3], including emissions from open flares associated with gas/oil extractive industry which are about (25 ± 8) Gg/yr. We analyzed the data on wood fires (detailing crown, ground and underground fires in forests and fires on non-forest lands) with their spatial and seasonal variations during 15 years (2000-2014). Different combustion factors [4] and BC emission coefficients [5] were used in calculations for different types of burning. Russian total average annual BC emission from fires, occurring mainly in summertime, was estimated as 30 Gg with large variations (4-100 Gg/yr) from year to year. Asian territory emits about 90% of this value. We estimated anthropogenic (BC_A) and fires' (BC_F) contributions to BC air concentrations at different Russian Arctic points using the approach [6] - decadal back-trajectory analysis combined with spatial distribution of sensitivity pollution emission function (SPEF). Extraordinary atmospheric circulation causing, to a great extent, abnormally intensive fires in the middle latitudes often leads to a decrease in SPEF values for these territories. As a result, fires are not so dangerous for the whole Arctic, as

  11. Hidden Markov models for estimating animal mortality from anthropogenic hazards

    EPA Science Inventory

    Carcasses searches are a common method for studying the risk of anthropogenic hazards to wildlife, including non-target poisoning and collisions with anthropogenic structures. Typically, numbers of carcasses found must be corrected for scavenging rates and imperfect detection. ...

  12. Quantifying the Anthropogenic Footprint in Eastern China.

    PubMed

    Meng, Chunlei; Dou, Youjun

    2016-01-01

    Urban heat island (UHI) is one of the most focuses in urban climate study. The parameterization of the anthropogenic heat (AH) is crucial important in UHI study, but universal method to parameterize the spatial pattern of the AH is lacking now. This paper uses the NOAA DMSP/OLS nighttime light data to parameterize the spatial pattern of the AH. Two experiments were designed and performed to quantify the influences of the AH to land surface temperature (LST) in eastern China and 24 big cities. The annual mean heating caused by AH is up to 1 K in eastern China. This paper uses the relative LST differences rather than the absolute LST differences between the control run and contrast run of common land model (CoLM) to find the drivers. The heating effect of the anthropogenic footprint has less influence on relatively warm and wet cities. PMID:27067132

  13. Quantifying the Anthropogenic Footprint in Eastern China

    PubMed Central

    Meng, Chunlei; Dou, Youjun

    2016-01-01

    Urban heat island (UHI) is one of the most focuses in urban climate study. The parameterization of the anthropogenic heat (AH) is crucial important in UHI study, but universal method to parameterize the spatial pattern of the AH is lacking now. This paper uses the NOAA DMSP/OLS nighttime light data to parameterize the spatial pattern of the AH. Two experiments were designed and performed to quantify the influences of the AH to land surface temperature (LST) in eastern China and 24 big cities. The annual mean heating caused by AH is up to 1 K in eastern China. This paper uses the relative LST differences rather than the absolute LST differences between the control run and contrast run of common land model (CoLM) to find the drivers. The heating effect of the anthropogenic footprint has less influence on relatively warm and wet cities. PMID:27067132

  14. Quantifying the Anthropogenic Footprint in Eastern China.

    PubMed

    Meng, Chunlei; Dou, Youjun

    2016-04-12

    Urban heat island (UHI) is one of the most focuses in urban climate study. The parameterization of the anthropogenic heat (AH) is crucial important in UHI study, but universal method to parameterize the spatial pattern of the AH is lacking now. This paper uses the NOAA DMSP/OLS nighttime light data to parameterize the spatial pattern of the AH. Two experiments were designed and performed to quantify the influences of the AH to land surface temperature (LST) in eastern China and 24 big cities. The annual mean heating caused by AH is up to 1 K in eastern China. This paper uses the relative LST differences rather than the absolute LST differences between the control run and contrast run of common land model (CoLM) to find the drivers. The heating effect of the anthropogenic footprint has less influence on relatively warm and wet cities.

  15. Quantifying the Anthropogenic Footprint in Eastern China

    NASA Astrophysics Data System (ADS)

    Meng, Chunlei; Dou, Youjun

    2016-04-01

    Urban heat island (UHI) is one of the most focuses in urban climate study. The parameterization of the anthropogenic heat (AH) is crucial important in UHI study, but universal method to parameterize the spatial pattern of the AH is lacking now. This paper uses the NOAA DMSP/OLS nighttime light data to parameterize the spatial pattern of the AH. Two experiments were designed and performed to quantify the influences of the AH to land surface temperature (LST) in eastern China and 24 big cities. The annual mean heating caused by AH is up to 1 K in eastern China. This paper uses the relative LST differences rather than the absolute LST differences between the control run and contrast run of common land model (CoLM) to find the drivers. The heating effect of the anthropogenic footprint has less influence on relatively warm and wet cities.

  16. Spatial resolution of anthropogenic heat fluxes into urban aquifers.

    PubMed

    Benz, Susanne A; Bayer, Peter; Menberg, Kathrin; Jung, Stephan; Blum, Philipp

    2015-08-15

    Urban heat islands in the subsurface contain large quantities of energy in the form of elevated groundwater temperatures caused by anthropogenic heat fluxes (AHFS) into the subsurface. The objective of this study is to quantify these AHFS and the heat flow they generate in two German cities, Karlsruhe and Cologne. Thus, statistical and spatial analytical heat flux models were developed for both cities. The models include the spatial representation of various sources of AHFS: (1) elevated ground surface temperatures, (2) basements, (3) sewage systems, (4) sewage leakage, (5) subway tunnels, and (6) district heating networks. The results show that the district heating networks induce the largest AHFS with values greater than 60 W/m(2) and one order of magnitude higher than fluxes from other sources. A covariance analysis indicates that the spatial distribution of the total flux depends mainly on the thermal gradient in the unsaturated zone. On a citywide scale, basements and elevated ground surface temperatures are the dominant sources of heat flow. Overall, 2.1 PJ/a and 1.0 PJ/a of heat are accumulated on average in Karlsruhe and the western part of Cologne, respectively. Extracting this anthropogenically originated energy could sustainably supply significant parts of the urban heating demand. Furthermore, using this heat could also keep groundwater temperatures from rising further.

  17. Spatial resolution of anthropogenic heat fluxes into urban aquifers.

    PubMed

    Benz, Susanne A; Bayer, Peter; Menberg, Kathrin; Jung, Stephan; Blum, Philipp

    2015-08-15

    Urban heat islands in the subsurface contain large quantities of energy in the form of elevated groundwater temperatures caused by anthropogenic heat fluxes (AHFS) into the subsurface. The objective of this study is to quantify these AHFS and the heat flow they generate in two German cities, Karlsruhe and Cologne. Thus, statistical and spatial analytical heat flux models were developed for both cities. The models include the spatial representation of various sources of AHFS: (1) elevated ground surface temperatures, (2) basements, (3) sewage systems, (4) sewage leakage, (5) subway tunnels, and (6) district heating networks. The results show that the district heating networks induce the largest AHFS with values greater than 60 W/m(2) and one order of magnitude higher than fluxes from other sources. A covariance analysis indicates that the spatial distribution of the total flux depends mainly on the thermal gradient in the unsaturated zone. On a citywide scale, basements and elevated ground surface temperatures are the dominant sources of heat flow. Overall, 2.1 PJ/a and 1.0 PJ/a of heat are accumulated on average in Karlsruhe and the western part of Cologne, respectively. Extracting this anthropogenically originated energy could sustainably supply significant parts of the urban heating demand. Furthermore, using this heat could also keep groundwater temperatures from rising further. PMID:25930242

  18. Analyses of scattering characteristics of chosen anthropogenic aerosols

    NASA Astrophysics Data System (ADS)

    Kaszczuk, Miroslawa; Mierczyk, Zygmunt; Muzal, Michal

    2008-10-01

    In the work, analyses of scattering profile of chosen anthropogenic aerosols for two wavelengths (λ1 = 1064 nm and λ2 = 532 nm) were made. As an example of anthropogenic aerosol three different pyrotechnic mixtures (DM11, M2, M16) were taken. Main parameters of smoke particles were firstly analyzed and well described, taking particle shape and size into special consideration. Shape of particles was analyzed on the basis of SEM pictures, and particle size was measured. Participation of particles in each fixed fraction characterized by range of sizes was analyzed and parameters of smoke particles of characteristic sizes and function describing aerosol size distribution (ASD) were determinated. Analyses of scattering profiles were carried out on the basis of both model of scattering on spherical and nonspherical particles. In the case of spherical particles Rayleigh-Mie model was used and for nonspherical particles analyses firstly model of spheroids was used, and then Rayleigh-Mie one. For each characteristic particle one calculated value of four parameters (effective scattering cross section σSCA, effective backscattering cross section σBSCA, scattering efficiency QSCA, backscattering efficiency QBSCA) and value of backscattering coefficient β for whole particles population. Obtained results were compared with the same parameters calculated for natural aerosol (cirrus cloud).

  19. Anthropogenic Sulfate, Clouds, and Climate Forcing

    NASA Technical Reports Server (NTRS)

    Ghan, Steven J.

    1997-01-01

    This research work is a joint effort between research groups at the Battelle Pacific Northwest Laboratory, Virginia Tech University, Georgia Institute of Technology, Brookhaven National Laboratory, and Texas A&M University. It has been jointly sponsored by the National Aeronautics and Space Administration, the U.S. Department of Energy, and the U.S. Environmental Protection Agency. In this research, a detailed tropospheric aerosol-chemistry model that predicts oxidant concentrations as well as concentrations of sulfur dioxide and sulfate aerosols has been coupled to a general circulation model that distinguishes between cloud water mass and cloud droplet number. The coupled model system has been first validated and then used to estimate the radiative impact of anthropogenic sulfur emissions. Both the direct radiative impact of the aerosols and their indirect impact through their influence on cloud droplet number are represented by distinguishing between sulfuric acid vapor and fresh and aged sulfate aerosols, and by parameterizing cloud droplet nucleation in terms of vertical velocity and the number concentration of aged sulfur aerosols. Natural sulfate aerosols, dust, and carbonaceous and nitrate aerosols and their influence on the radiative impact of anthropogenic sulfate aerosols, through competition as cloud condensation nuclei, will also be simulated. Parallel simulations with and without anthropogenic sulfur emissions are performed for a global domain. The objectives of the research are: To couple a state-of-the-art tropospheric aerosol-chemistry model with a global climate model. To use field and satellite measurements to evaluate the treatment of tropospheric chemistry and aerosol physics in the coupled model. To use the coupled model to simulate the radiative (and ultimately climatic) impacts of anthropogenic sulfur emissions.

  20. The topographic signature of anthropogenic geomorphic processes

    NASA Astrophysics Data System (ADS)

    Tarolli, P.; Sofia, G.

    2014-12-01

    Within an abiotic-dominated context, geomorphologic patterns and dynamics are single expressions of trade-offs between the physical resistance forces, and the mechanical and chemical forces related to climate and erosion. Recently, however, it has become essential for the geomorphological community to take into account also biota as a fundamental geomorphologic agent acting from local to regional scales. However, while there is a recent flourishing literature about the impacts of vegetation on geomorphic processes, the study of anthropogenic pressure on geomorphology is still at its early stages. Humans are indeed among the most prominent geomorphic agents, redistributing land surface, and causing drastic changes to the geomorphic organization of the landscape (e.g. intensive agriculture, urbanization), with direct consequences on land degradation and watershed response. The reconstruction or identification of artificial or anthropogenic topographies, therefore, provides a mechanism for quantifying anthropogenic changes to the landscape systems in the context of the Anthropocene epoch. High-resolution topographic data derived from the recent remote sensing technologies (e.g. lidar, SAR, SfM), offer now new opportunities to recognize better understand geomorphic processes from topographic signatures, especially in engineered landscapes where the direct anthropic alteration of processes is significant. It is possible indeed to better recognize human-induced geomorphic and anthropogenic features (e.g. road networks, agricultural terraces), and the connected erosion. The study presented here may allow improved understanding and targeted mitigation of the processes driving geomorphic changes during urban development and help guide future research directions for development-based watershed studies. Human society is deeply affecting the environment with consequences on the landscape. It is therefore fundamental to establish greater management control over the Earth

  1. Blue whales respond to anthropogenic noise.

    PubMed

    Melcón, Mariana L; Cummins, Amanda J; Kerosky, Sara M; Roche, Lauren K; Wiggins, Sean M; Hildebrand, John A

    2012-01-01

    Anthropogenic noise may significantly impact exposed marine mammals. This work studied the vocalization response of endangered blue whales to anthropogenic noise sources in the mid-frequency range using passive acoustic monitoring in the Southern California Bight. Blue whales were less likely to produce calls when mid-frequency active sonar was present. This reduction was more pronounced when the sonar source was closer to the animal, at higher sound levels. The animals were equally likely to stop calling at any time of day, showing no diel pattern in their sensitivity to sonar. Conversely, the likelihood of whales emitting calls increased when ship sounds were nearby. Whales did not show a differential response to ship noise as a function of the time of the day either. These results demonstrate that anthropogenic noise, even at frequencies well above the blue whales' sound production range, has a strong probability of eliciting changes in vocal behavior. The long-term implications of disruption in call production to blue whale foraging and other behaviors are currently not well understood. PMID:22393434

  2. Exploring the engine of anthropogenic iron cycles

    PubMed Central

    Müller, Daniel B.; Wang, Tao; Duval, Benjamin; Graedel, T. E.

    2006-01-01

    Stocks of products in use are the pivotal engines that drive anthropogenic metal cycles: They support the lives of people by providing services to them; they are sources for future secondary resources (scrap); and demand for in-use stocks generates demand for metals. Despite their great importance and their impacts on other parts of the metal cycles and the environment, the study of in-use stocks has heretofore been widely neglected. Here we investigate anthropogenic and geogenic iron stocks in the United States (U.S.) by analyzing the iron cycle over the period 1900–2004. Our results show the following. (i) Over the last century, the U.S. iron stock in use increased to 3,200 Tg (million metric tons), which is the same order of magnitude as the remaining U.S. iron stock in identified ores. On a global scale, anthropogenic iron stocks are less significant compared with natural ores, but their relative importance is increasing. (ii) With a perfect recycling system, the U.S. could substitute scrap utilization for domestic mining. (iii) The per-capita in-use iron stock reached saturation at 11–12 metric tons in ≈1980. This last finding, if applicable to other economies as well, could allow a significant improvement of long-term forecasting of steel demand and scrap availability in emerging market economies and therefore has major implications for resource sustainability, recycling technology, and industrial and governmental policy. PMID:17053079

  3. Anthropogenic transformation of the terrestrial biosphere.

    PubMed

    Ellis, Erle C

    2011-03-13

    Human populations and their use of land have transformed most of the terrestrial biosphere into anthropogenic biomes (anthromes), causing a variety of novel ecological patterns and processes to emerge. To assess whether human populations and their use of land have directly altered the terrestrial biosphere sufficiently to indicate that the Earth system has entered a new geological epoch, spatially explicit global estimates of human populations and their use of land were analysed across the Holocene for their potential to induce irreversible novel transformation of the terrestrial biosphere. Human alteration of the terrestrial biosphere has been significant for more than 8000 years. However, only in the past century has the majority of the terrestrial biosphere been transformed into intensively used anthromes with predominantly novel anthropogenic ecological processes. At present, even were human populations to decline substantially or use of land become far more efficient, the current global extent, duration, type and intensity of human transformation of ecosystems have already irreversibly altered the terrestrial biosphere at levels sufficient to leave an unambiguous geological record differing substantially from that of the Holocene or any prior epoch. It remains to be seen whether the anthropogenic biosphere will be sustained and continue to evolve.

  4. Seasonal variability in anthropogenic halocarbon emissions.

    PubMed

    Gentner, Drew R; Miller, Angela M; Goldstein, Allen H

    2010-07-15

    Ambient concentrations of eight predominantly anthropogenic halocarbons were measured via in situ gas chromatography in California's South Coast air basin for both summer and fall during the 2005 Study of Organic Aerosols at Riverside (SOAR). Ongoing emissions of the banned halocarbons methylchloroform and CFC-11 were observed in the South Coast air basin, whereas CFC-113 emissions have effectively ceased. We estimate anthropogenic emissions in the South Coast air basin for methylchloroform, CFC-11, HCFC-141b, chloroform, tetrachloroethene (PCE), trichloroethylene (TCE), and dichloromethane based on regressions of halocarbon to carbon monoxide mixing ratios and carbon monoxide emission inventories. We estimate per capita methylchloroform and chloroform emissions in the South Coast air basin for the year 2005 to be 6.6 +/- 0.4 g/(person.year) and 19 +/- 1 g/(person.year), respectively. We compare our results to national emission estimates calculated from previous work; for several compounds, emissions in the South Coast air basin are significantly lower than national per capita emissions. We observed strong seasonal differences in anthropogenic emissions of methylchloroform and chloroform; emissions were 4.5 and 2.5 times greater in summer than in fall, respectively. Possible seasonal sources include landfills and water chlorination. We conclude that seasonal variability in methylchloroform emissions has not been included in previous inventories and may cause errors in methylchloroform emission estimates after the year 2000 and seasonally resolved inversion calculations of hydroxyl radical abundance. PMID:20536226

  5. Blue whales respond to anthropogenic noise.

    PubMed

    Melcón, Mariana L; Cummins, Amanda J; Kerosky, Sara M; Roche, Lauren K; Wiggins, Sean M; Hildebrand, John A

    2012-01-01

    Anthropogenic noise may significantly impact exposed marine mammals. This work studied the vocalization response of endangered blue whales to anthropogenic noise sources in the mid-frequency range using passive acoustic monitoring in the Southern California Bight. Blue whales were less likely to produce calls when mid-frequency active sonar was present. This reduction was more pronounced when the sonar source was closer to the animal, at higher sound levels. The animals were equally likely to stop calling at any time of day, showing no diel pattern in their sensitivity to sonar. Conversely, the likelihood of whales emitting calls increased when ship sounds were nearby. Whales did not show a differential response to ship noise as a function of the time of the day either. These results demonstrate that anthropogenic noise, even at frequencies well above the blue whales' sound production range, has a strong probability of eliciting changes in vocal behavior. The long-term implications of disruption in call production to blue whale foraging and other behaviors are currently not well understood.

  6. Lead poisoning.

    PubMed Central

    Landrigan, P J; Todd, A C

    1994-01-01

    Lead poisoning is the most common disease of environmental origin in the United States today. Adult lead poisoning results primarily from exposure by inhalation in the workplace. Pediatric lead poisoning results principally from the ingestion of lead from environmental media, including paint chips, dust, soil, drinking water, ceramics, and medications. Lead is toxic to many organ systems, among them developing erythrocytes, the kidneys, and the nervous system. Lead-induced toxicity to the central nervous system causes delayed development, diminished intelligence, and altered behavior. In young children, this effect has been demonstrated convincingly to occur at blood lead levels between 10 and 20 micrograms per dl. The Centers for Disease Control and Prevention has recommended that a blood lead level of 10 micrograms per dl or higher be considered evidence of increased lead absorption, and the National Academy of Sciences has concurred in that recommendation. Unresolved issues in need of further study include the frequency of screening young children for lead, the question of whether women should be offered screening for lead before conceiving a pregnancy, the role of x-ray fluorescence analysis in assessing lead in bone, and the appropriate legislative response of the United States government to lead-based paint abatement. PMID:7941534

  7. Effects of anthropogenic heat release upon the urban climate in a Japanese megacity.

    PubMed

    Narumi, Daisuke; Kondo, Akira; Shimoda, Yoshiyuki

    2009-05-01

    This report presents results of investigations of the influence of anthropogenic heat release in Japanese megacity (Keihanshin district) upon the urban climate, using the energy database [Shimoda et al., 1999. Estimation and evaluation of artificial waste heat in urban area. Selected Papers from the Conference ICB-ICUC'99 WCASP-50 WMO/TD no. 1026] as a part of the land-surface boundary conditions of a mesoscale meteorological simulation model. The calculated results related to atmospheric temperature distribution were similar to observed values not only for daily averages but also for amplitudes and phases of diurnal change. To reproduce accurately, it is essential to reproduce urban characteristics such as an urban canopy and anthropogenic heat release in a fine resolution mesh. We attempted an analysis using current data for anthropogenic heat and under uniform heat release conditions, to investigate temporal and spatial characteristics in relation to the influence of anthropogenic heat release on the urban climate. The results of investigation into the influence of anthropogenic heat release on atmospheric temperature using current data indicate that the amount of heat released is lower at night than during the day, but the temperature rise is nearly 3 times greater. Results of investigation into the influence of anthropogenic heat release on wind systems using current data indicate that the onset of land breezes is delayed, particularly in a coastal area. Investigation into the temporal characteristics related to the influence of anthropogenic heat release under uniform heat release conditions showed a maximum influence on temperature during the predawn period.

  8. Lead poisoning

    MedlinePlus

    ... lead is still found in some modern faucets. Soil contaminated by decades of car exhaust or years ... house paint scrapings. Lead is more common in soil near highways and houses. Hobbies involving soldering, stained ...

  9. Future Climate Impacts of Direct Radiative Forcing Anthropogenic Aerosols, Tropospheric Ozone, and Long-lived Greenhouse Gases

    NASA Technical Reports Server (NTRS)

    Chen, Wei-Ting; Liao, Hong; Seinfeld, John H.

    2007-01-01

    Long-lived greenhouse gases (GHGs) are the most important driver of climate change over the next century. Aerosols and tropospheric ozone (O3) are expected to induce significant perturbations to the GHG-forced climate. To distinguish the equilibrium climate responses to changes in direct radiative forcing of anthropogenic aerosols, tropospheric ozone, and GHG between present day and year 2100, four 80-year equilibrium climates are simulated using a unified tropospheric chemistry-aerosol model within the Goddard Institute for Space Studies (GISS) general circulation model (GCM) 110. Concentrations of sulfate, nitrate, primary organic (POA) carbon, secondary organic (SOA) carbon, black carbon (BC) aerosols, and tropospheric ozone for present day and year 2100 are obtained a priori by coupled chemistry-aerosol GCM simulations, with emissions of aerosols, ozone, and precursors based on the Intergovernmental Panel on Climate Change (IPCC) Special Report on Emissions Scenario (SRES) A2. Changing anthropogenic aerosols, tropospheric ozone, and GHG from present day to year 2100 is predicted to perturb the global annual mean radiative forcing by +0.18 (considering aerosol direct effects only), +0.65, and +6.54 W m(sup -2) at the tropopause, and to induce an equilibrium global annual mean surface temperature change of +0.14, +0.32, and +5.31 K, respectively, with the largest temperature response occurring at northern high latitudes. Anthropogenic aerosols, through their direct effect, are predicted to alter the Hadley circulation owing to an increasing interhemispheric temperature gradient, leading to changes in tropical precipitation. When changes in both aerosols and tropospheric ozone are considered, the predicted patterns of change in global circulation and the hydrological cycle are similar to those induced by aerosols alone. GHG-induced climate changes, such as amplified warming over high latitudes, weakened Hadley circulation, and increasing precipitation over the

  10. Anthropogenic features and hillslope processes interaction

    NASA Astrophysics Data System (ADS)

    Tarolli, Paolo; Sofia, Giulia

    2016-04-01

    Topography emerges as a result of natural driving forces, but some human activities (such as mining, agricultural practices and the construction of road networks) directly or indirectly move large quantities of soil, which leave clear topographic signatures embedded on the Earth's morphology. These signatures can cause drastic changes to the geomorphological organization of the landscape, with direct consequences on Earth surface processes (Tarolli and Sofia, 2016). To this point, the present research investigates few case studies highlighting the influences of anthropogenic topographic signatures on hillslope processes, and it shows the effectiveness of High-Resolution Topography (HRT) derived from the recent remote sensing technologies (e.g. lidar, satellite, structure from motion photogrammetry), to better understand this interaction. The first example is related to agricultural terraces. In recent times, terraced areas acquired a new relevance to modern concerns about erosion and land instability, being the agricultural land mostly threatened by abandonment or intensification and specialization of agriculture, resulting in more landslide-prone bench terraces, or heavy land levelling with increased erosion. The second case study discusses about the role of agricultural and forest roads on surface erosion and landslides. The third case study investigates geomorphic processes in an open pit mine. In all case studies, HRT served as the basis for the development of new methodologies able to recognize and analyze changes on Earth surface processes along hillslopes. The results show how anthropogenic elements have crucial effects on sediment production and sediment delivery, also influencing the landscape connectivity. The availability of HRT can improve our ability to actually model anthropogenic morphologies, quantify them, and analyse the links between anthropogenic elements and geomorphic processes. The results presented here, and the creation and dissemination of

  11. Plant ecology. Anthropogenic environmental changes affect ecosystem stability via biodiversity.

    PubMed

    Hautier, Yann; Tilman, David; Isbell, Forest; Seabloom, Eric W; Borer, Elizabeth T; Reich, Peter B

    2015-04-17

    Human-driven environmental changes may simultaneously affect the biodiversity, productivity, and stability of Earth's ecosystems, but there is no consensus on the causal relationships linking these variables. Data from 12 multiyear experiments that manipulate important anthropogenic drivers, including plant diversity, nitrogen, carbon dioxide, fire, herbivory, and water, show that each driver influences ecosystem productivity. However, the stability of ecosystem productivity is only changed by those drivers that alter biodiversity, with a given decrease in plant species numbers leading to a quantitatively similar decrease in ecosystem stability regardless of which driver caused the biodiversity loss. These results suggest that changes in biodiversity caused by drivers of environmental change may be a major factor determining how global environmental changes affect ecosystem stability.

  12. Rarity value and species extinction: the anthropogenic Allee effect.

    PubMed

    Courchamp, Franck; Angulo, Elena; Rivalan, Philippe; Hall, Richard J; Signoret, Laetitia; Bull, Leigh; Meinard, Yves

    2006-11-01

    Standard economic theory predicts that exploitation alone is unlikely to result in species extinction because of the escalating costs of finding the last individuals of a declining species. We argue that the human predisposition to place exaggerated value on rarity fuels disproportionate exploitation of rare species, rendering them even rarer and thus more desirable, ultimately leading them into an extinction vortex. Here we present a simple mathematical model and various empirical examples to show how the value attributed to rarity in some human activities could precipitate the extinction of rare species-a concept that we term the anthropogenic Allee effect. The alarming finding that human perception of rarity can precipitate species extinction has serious implications for the conservation of species that are rare or that may become so, be they charismatic and emblematic or simply likely to become fashionable for certain activities.

  13. Early Anthropogenic Transformation of the Danube-Black Sea System

    PubMed Central

    Giosan, Liviu; Coolen, Marco J. L.; Kaplan, Jed O.; Constantinescu, Stefan; Filip, Florin; Filipova-Marinova, Mariana; Kettner, Albert J.; Thom, Nick

    2012-01-01

    Over the last century humans have altered the export of fluvial materials leading to significant changes in morphology, chemistry, and biology of the coastal ocean. Here we present sedimentary, paleoenvironmental and paleogenetic evidence to show that the Black Sea, a nearly enclosed marine basin, was affected by land use long before the changes of the Industrial Era. Although watershed hydroclimate was spatially and temporally variable over the last ~3000 years, surface salinity dropped systematically in the Black Sea. Sediment loads delivered by Danube River, the main tributary of the Black Sea, significantly increased as land use intensified in the last two millennia, which led to a rapid expansion of its delta. Lastly, proliferation of diatoms and dinoflagellates over the last five to six centuries, when intensive deforestation occurred in Eastern Europe, points to an anthropogenic pulse of river-borne nutrients that radically transformed the food web structure in the Black Sea. PMID:22937219

  14. Possible Influence of Anthropogenic Aerosols on Cirrus Clouds and Anthropogenic Forcing

    SciTech Connect

    Penner, Joyce E.; Chen, Yang; Wang, Minghuai; Liu, Xiaohong

    2009-02-03

    Cirrus clouds have a net warming effect on the atmosphere and cover about 30% of the Earth’s area. Aerosol particles initiate ice formation in the upper troposphere through modes of action that include homogeneous freezing of solution droplets, heterogeneous nucleation on solid particles immersed in a solution, and deposition nucleation of vapor onto solid particles. Here, we examine the possible change in ice number concentration from anthropogenic soot originating from surface sources of fossil fuel and biomass burning, from anthropogenic sulfate aerosols, and from aircraft that deposit their aerosols directly in the upper troposphere. We find that fossil fuel and biomass burning soot aerosols exert a radiative forcing of -0.68 to 0.01 Wm-2 while anthropogenic sulfate aerosols exert a forcing of -0.01 to 0.18 Wm-2. Our calculations show that the sign of the forcing by aircraft soot depends on the model configuration and can be both positive or negative, ranging from -0.16 to 0.02 Wm-2. The magnitude of the forcing in cirrus clouds can be comparable to the forcing exerted by anthropogenic aerosols on warm clouds, but this forcing has not been included in past assessments of the total anthropogenic radiative forcing of climate.

  15. Lead concentration and isotope chronology in two coastal environments in Western and South East Asia

    NASA Astrophysics Data System (ADS)

    Carrasco, G. G.; Chen, M.; Boyle, E. A.; Zhao, N.; Nurhati, I. S.; Gevao, B.; al Ghadban, A.; Switzer, A.; Lee, J. M.

    2014-12-01

    Lead is a trace metal that is closely related to anthropogenic activity, mainly via leaded gasoline and coal combustion. The study of lead concentrations and isotopes in seawater, sediments, corals and aerosols allows for a systematic look at its sources and their time evolution in a natural environment. We will discuss results from two projects in Western and South East Asia, regions that have seen dramatic socio-economical changes over the past half-century that may have left environmental signals. These results highlight the usefulness of the method, indicate the degree of complexity of these systems, and point to the need for a continuous monitoring of anthropogenic trace metals in the small-medium coastal scale to be able to asses the larger scale effects of human activity. On the one hand, coastal Kuwait is heavily influenced by the Shat al-Arab river and shows a clear anthropogenic signature from Kuwait city. A mix of two sources can be tracked through the coral and sediment chronological records, with Pb206/Pb207 ratios (1.202 and 1.151) that approach the suspected source values (1.21 and 1.12) and eliminate the possibility of other sources. Through a wide sediment geographic distribution, the strength of the anthropogenic signature is modulated. On the other hand, Singapore offers a more complex system, where an apparent mix of two sources (extreme isotope ratios 1.215 and ~1.14) occurs also, but where either an unresolved potentially important third source (isotope ratio ~1.18), or an isotope exchange process should be invoked. The sediment and coral records allows us to track the changes through time; however, there seems to be incongruence with the aerosol isotope record. Further potential sources are being explored currently and will be discussed.

  16. Challenges for present and future estimates of anthropogenic carbon in the Indian Ocean

    NASA Astrophysics Data System (ADS)

    Goyet, C.; Touratier, F.

    One of the main challenges we face today is to determine the evolution of the penetration of anthropogenic CO2 into the Indian Ocean and its impacts on marine and human life. Anthropogenic CO2 reaches the ocean via air-sea interactions as well as riverine inputs. It is then stored in the ocean and follows the oceanic circulation. As the carbon dioxide from the atmosphere penetrates into the sea, it reacts with water and acidifies the ocean. Consequently, the whole marine ecosystem is perturbed, thus potentially affecting the food web, which has, in turn, a direct impact on seafood supply for humans. Naturally, this will mainly affect the growing number of people living in coastal areas. Although anthropogenic CO2 in the ocean is identical with natural CO2 and therefore cannot be detected alone, many approaches are available today to estimate it. Since most of the results of these methods are globally in agreement, here we chose one of these methods, the tracer using oxygen, total inorganic carbon, and total alkalinity (TrOCA) approach, to compute the 3-D distribution of the anthropogenic CO2 concentrations throughout the Indian Ocean. The results of this distribution clearly illustrate the contrast between the Arabian Sea and the Bay of Bengal. They further show the importance of the southern part of this ocean that carries some anthropogenic CO2 at great depths. In order to determine the future anthropogenic impacts on the Indian Ocean, it is urgent and necessary to understand the present state. As the seawater temperature increases, how and how fast will the ocean circulation change? What will the impacts on seawater properties be? Many people are living on the bordering coasts, how will they be affected?

  17. Current inventory of anthropogenic carbon dioxide in the North Pacific

    SciTech Connect

    Cline, J.D.; Feely, R.A.; Kelly-Hansen, K.; Gendron, J.F.; Wisegarver, D.P.

    1985-01-01

    The atmospheric increase of carbon dioxide is the result of the burning of fossil fuels and massive deforestation currently underway. Since 1958, the atmosphere CO/sub 2/ concentration has risen from about 315 ppm to about 343 ppm. The major repositories for anthropogenic CO/sub 2/ are the oceans and the atmosphere. The distributions of freon-11, as a surrogate tracer, have been combined with precise measurements of total carbon dioxide, total alkalinity oxygen, nutrient and hydrography in order to estimate the amount of excess CO/sub 2/ in the subarctic water of the north Pacific gyre. Calculations indicate that approximately 4 x 10 to the 1B power G of excess carbon, or about 2% of the total estimated fossil-fuel derived carbon input now resides in the mixed layer and thermocline waters of the north Pacific gyre.

  18. [Net anthropogenic nitrogen input to Huaihe River Basin, China during 1990-2010].

    PubMed

    Zhang, Wang-shou; Su, Jing-jun; Du, Xin-zhong; Li, Xu-yong

    2015-06-01

    Social economy in Huaihe River Basin had undergone enormous changes during 1990-2010. The grain yield had increased by 58%, from 64.14 million tons to 101.21 million tons, and the urbanization rate had increased by 22%, from 13% to 35%. Assessing the negative impacts of these high intensive human activities caused by rapid social development on terrestrial ecosystem would serve as a scientific basis for quantitative management of regional ecology. This paper estimated the spatial and temporal distribution of net anthropogenic nitrogen input (NANI) in Huaihe River Basin during 1990-2010. The results showed that there was an increasing trend in NANI in the period of 1990-2001, and after that this trend was slower. The NANI increased from approximately 17232 kg N · km(-2) · a(-1) in 1990 to a peak of 28771 kg N · km(-2) · a(-1) in 2003, and then declined to 26415 kg N · km(-2) · a(-1) in 2010. Chemical fertilizer and atmospheric deposition were the largest two sources of NANI, followed by food & feed import and biological nitrogen. Contributions from both chemical fertilizer and atmospheric deposition had been increasing continuously, respectively from 64% and 16% in 1990 to 77% and 19%. Our findings implied that the shift from fertilizer-supported agriculture and fossil fuel-supported industry to sci-tech lead economic development is urgently needed. PMID:26572039

  19. Exploring the Capabilities of Satellite Observation of Anthropogenic Sulfur Dioxide (SO2) in the Lower Atmosphere

    NASA Astrophysics Data System (ADS)

    Yang, K.; Krotkov, N. A.; Li, C.; He, H.; Dickerson, R. R.

    2012-12-01

    Anthropogenic activities, such as fuel combustion, oil refining, and metal smelting, emit sulfur dioxide (SO2) into the atmospheric planetary boundary layer (PBL), leading to air quality degradation near the source regions. SO2 in the air is oxidized to form sulfate aerosols, which may have a significant impact on regional air quality and climate. Sulfate aerosols are usually removed from the atmosphere through acid deposition, which can damage the environment and ecosystems. SO2 and sulfate aerosols are sometimes lifted into the middle or upper troposphere and subsequently transported over long distances, affecting remote regions. Space-borne UV instruments, such as Aura/OMI, MetOp/GOME-2, and NPP/OMPS, provide a unique perspective on the spatial and temporal distribution of SO2 over the globe. In this presentation, we will describe the recent advances in retrieval algorithm that provide improved detection and quantification of PBL SO2, and compare the new retrievals with the operational OMI SO2 products to show significant reduction in noise and bias. We will also present validation results obtained by the comparisons with co-located in-situ aircraft measurements to illustrate improved accuracy achieved with the advanced algorithm.

  20. Predicting woodrat (Neotoma) responses to anthropogenic warming from studies of the palaeomidden record

    USGS Publications Warehouse

    Smith, Felisa A.; Betancourt, Julio L.

    2006-01-01

    Aim The influence of anthropogenic climate change on organisms is an area of great scientific concern. Increasingly there is recognition that abrupt climate transitions have occurred over the late Quaternary; studies of these shifts may yield insights into likely biotic responses to contemporary warming. Here, we review research undertaken over the past decade investigating the response of Neotoma (woodrats) body size and distribution to climate change over the late Quaternary (the last 40,000 years). By integrating information from woodrat palaeomiddens, historical museum specimens and field studies of modern populations, we identify potential evolutionary responses to climate change occurring over a variety of temporal and spatial scales. Specifically, we characterize climatic thresholds in the past that led to local species extirpation and/or range alterations rather than in situ adaptation, and apply them to anticipate potential biotic responses to anthropogenic climate change. Location Middens were collected at about 55 sites scattered across the western United States, ranging from about 34 to 46° N and about 104 to 116° W, respectively. Data for modern populations were drawn from studies conducted in Death Valley, California, Missoula, Montana and the Sevilleta LTER site in central New Mexico. Methods We analysed faecal pellets from midden series collected at numerous cave sites across the western United States. From these we estimated body mass using techniques validated in earlier studies. We compared body size fluctuations at different elevations in different regions and integrated these results with studies investigating temperature–body size tradeoffs in modern animals. We also quantify the rapidity of the size changes over the late Quaternary to estimate the evolutionary capacity of woodrats to deal with predicted rates of anthropogenic climate change over the next century. Results We find remarkable similarities across the geographical range to

  1. Lead isotopic compositions of common arsenical pesticides used in New England

    USGS Publications Warehouse

    Ayuso, Robert; Foley, Nora; Robinson, Gilpin; Wandless, Gregory; Dillingham, Jeremy

    2004-01-01

    The three most important arsenical pesticides and herbicides that were extensively used on apple, blueberry, and potato crops in New England from mid-1800s to recent times are lead arsenate, calcium arsenate, and sodium arsenate. Lead arsenate was probably the most heavily used of the arsenical pesticides until it was banned in 1988. Other metal-arsenic pesticides were also used but in lesser amounts. A recent report identified areas in New England where arsenical pesticides were used extensively (Robinson and Ayuso, 2004). On the basis of factor analysis of metal concentrations in stream sediment samples, a positive correlation with pesticide use was shown in regions having stream sediment sample populations that contained concentrations of high arsenic and lead. Lead isotope compositions of stream sediments from areas with heavy use of the pesticides could not be entirely explained by lead originating from rock sulfides and their weathering products. An industrial lead contribution (mostly from atmospheric deposition of lead) was suggested in general to explain the lead isotopic distributions of the stream sediments that could not be accounted for by the natural lead in the environment. We concluded that when agricultural land previously contaminated with arsenical pesticides is urbanized, pesticide residues in the soils and stream sediments could be released into the groundwater. No lead isotopic data characterizing the compositions of pesticides were available for comparison. We have determined the lead isotopic compositions of commonly used pesticides in New England, such as lead arsenate, sodium metaarsenite, and calcium arsenate, in order to assist in future isotopic comparisons and to better establish anthropogenic sources of Pb and As. New data are also presented for copper acetoarsenite (or Paris green), methyl arsonic acid and methane arsonic acid, as well as for arsanilic acid, all of which are used as feed additives to promote swine and poultry growth

  2. MULTI-SCALE REMOTE SENSING MAPPING OF ANTHROPOGENIC IMPERVIOUS SURFACES: SPATIAL AND TEMPORAL SCALING ISSUES RELATED TO ECOLOGICAL AND HYDROLOGICAL LANDSCAPE ANALYSES

    EPA Science Inventory

    Anthropogenic impervious surfaces are leading contributors to non-point-source water pollution in urban watersheds. These human-created surfaces include such features as roads, parking lots, rooftops, sideways, and driveways. Aerial photography provides a historical vehicle for...

  3. Lead isotopes in the western North Atlantic: Transient tracers of pollutant lead inputs

    SciTech Connect

    Veron, A.J. |; Church, T.M.; Flegal, A.R.

    1998-08-01

    In the early 1980s, Patterson and colleagues demonstrated that most lead in oceanic surface waters had an anthropogenic origin. Their discovery occurred during the phasing out of leaded gasoline in North America initiated in the previous decade. The corresponding decrease in anthropogenic lead emissions, verified by Pb/{sup 210}Pb ratios, accounted for the systematic decline in lead concentrations in surface waters of the western Sargasso Sea. Subsequent changes in anthropogenic lead inputs to the western Sargasso Sea surface waters have been documented by measurements of lead concentrations, isotopic compositions ({sup 206}Pb/{sup 207}Pb, {sup 208}Pb/{sup 206}Pb), and Pb/{sup 210}Pb ratios in precipitation and seawater for the period of 1981 to 1994. These data indicate the easterly trade winds are now the primary source of atmospheric lead in Bermuda, and they confirm that the decline of lead concentrations in the North Atlantic is associated with the phasing out of leaded gasoline in North America and western Europe over the past decade. Moreover, temporal variations in the relative contribution of industrial lead inputs from the two sides of the North Atlantic over that period can be quantified based on differences in their isotopic composition. The transient character of those isotopic signatures also allows calculations of pollutant lead penetration rates into the mixed layer and upper thermocline of the western Sargasso Sea.

  4. Anthropogenic Elevation Change in the Pacific Northwest

    NASA Astrophysics Data System (ADS)

    Prush, V. B.; Lohman, R. B.

    2013-12-01

    Over the past few decades, interferometric synthetic aperture radar (InSAR) has emerged as a valuable tool for studying crustal deformation signals. Its applications to studies of tectonic and non-tectonic sources are varied, including earthquakes and fault-related processes, volcanic deformation, vegetation structure, and anthropogenic signals. In addition to studies of crustal deformation, the sensitivity of interferometric phase to topography makes InSAR a superb tool for the generation of digital elevation models (DEMs). While much of the focus of InSAR research in recent years has been on deformation, changes in the elevation of the ground surface can be of great scientific or societal interest as well. Examples include elevation and volume change due to anthropogenic processes such as landfill and open-pit mining operations, and natural processes such as glacier thinning or terrain alteration resulting from effusive volcanic eruptions. Our study describes two elevation change signals observed in the Pacific Northwest that are of anthropogenic origin. Using the baseline-dependent nature of the topographic component of interferometric phase, we have determined a proxy for canopy height using coherent interferometric phase differences between adjacent logged and forested regions, as well as a means for determining estimates of the amount and time history of material displaced during mining operations at the Centralia Coal Mine in Centralia, Washington. Quantifying the amount of surface change due to anthropogenic activities is not only critical for tracking the altering landscape of the Pacific Northwest and reducing the observed error in interferograms attributable to elevation change. Deforestation is one of the most significant contributors to global carbon emissions, and quantifying changes in vegetation structure can assist in efforts to monitor and mitigate the effects of deforestation on climate change. Similarly, mining operations can have a lasting

  5. Mapping of the thermal neutron distribution in the lead block assembly of the PS-211 experiment at CERN, using thermoluminescence and nuclear track detectors.

    PubMed

    Savvidis, E; Eleftheriadis, C A; Kitis, G

    2002-01-01

    The main purpose of the TARC (Transmutation by Adiabatic Resonance Crossing) experiment (PS-211), was to demonstrate the possibility to destroy efficiently Long-Lived Fission Fragments (LLFF) in Accelerator Driven Systems (ADS). The experimental set-up which consisted of a lead block with dimensions 3.3 x 3.3 x 3 m3, was installed in a CERN Proton Synchrotron (PS) beam line. The proton beam at 2.5 GeV/c and 3.5 GeV/c, was incident in the centre of the lead block assembly producing neutrons via spallation reactions. In this study, neutron flux measurements are presented in the lead block assembly using thermoluminescence and nuclear track detectors. The results are in good agreement with Monte Carlo calculations as well as with the results of the other methods used in the framework of the TARC experiment.

  6. Leading Democratically

    ERIC Educational Resources Information Center

    Brookfield, Stephen

    2010-01-01

    Democracy is the most venerated of American ideas, the one for which wars are fought and people die. So most people would probably agree that leaders should be able to lead well in a democratic society. Yet, genuinely democratic leadership is a relative rarity. Leading democratically means viewing leadership as a function or process, rather than…

  7. Violations of Gutenberg-Richter Relation in Anthropogenic Seismicity

    NASA Astrophysics Data System (ADS)

    Urban, Pawel; Lasocki, Stanislaw; Blascheck, Patrick; do Nascimento, Aderson Farias; Van Giang, Nguyen; Kwiatek, Grzegorz

    2016-05-01

    Anthropogenic seismicity (AS) is the undesired dynamic rockmass response to technological processes. AS environments are shallow hence their heterogeneities have important impact on AS. Moreover, AS is controlled by complex and changeable technological factors. This complicated origin of AS explains why models used in tectonic seismicity may be not suitable for AS. We study here four cases of AS, testing statistically whether the magnitudes follow the Gutenberg-Richter relation or not. The considered cases include the data from Mponeng gold mine in South Africa, the data observed during stimulation of geothermal well Basel 1 in Switzerland, the data from Acu water reservoir region in Brazil and the data from Song Tranh 2 hydropower plant region in Vietnam. The cases differ in inducing technologies, in the duration of periods in which they were recorded, and in the ranges of magnitudes. In all four cases the observed frequency-magnitude distributions statistically significantly differ from the Gutenberg-Richter relation. Although in all cases the Gutenberg-Richter b value changed in time, this factor turns out to be not responsible for the discovered deviations from the Gutenberg-Richter-born exponential distribution model. Though the deviations from Gutenberg-Richter law are not big, they substantially diminish the accuracy of assessment of seismic hazard parameters. It is demonstrated that the use of non-parametric kernel estimators of magnitude distribution functions improves significantly the accuracy of hazard estimates and, therefore, these estimators are recommended to be used in probabilistic analyses of seismic hazard caused by AS.

  8. Observations of anthropogenic cloud condensation nuclei

    NASA Technical Reports Server (NTRS)

    Hudson, James G.

    1990-01-01

    Cloud Condensation Nuclei (CCN) concentrations and spectral measurements obtained with the DRI instantaneous CCN spectrometer (Hudson, 1989) over the last few years are presented. The climatic importance of cloud microphysics has been pointed out. The particles which affect cloud microphysics are cloud condensation nuclei (CCN). The commonly-observed order of magnitude difference in cloud droplet concentrations between maritime and continental air masses (i.e., Squires, 1958) was determined to be caused by systematic differences in the concentrations of CCN between continental and maritime air masses (e.g., Twomey and Wojciechowski, 1969). Twomey (1977) first pointed out that cloud microphysics also affects the radiative properties of clouds. Thus continental and anthropogenic CCN could affect global temperature. Resolution of this Twomey effect requires answers to two questions - whether antropogenic CCN are a significant contribution to atmospheric CCN, and whether they are actually affecting cloud microphysics to an extent which is of climatic importance. The reasons for the contrast between continental and maritime CCN concentration are not understood. The question of the relative importance of anthropogenic CCN is addressed. These observations should shed light on this complex question although further research is being conducted in order to produce more quantitative answers. Accompanying CN measurements made with a TSI 3020 condensation nucleus (CN) counter are also presented.

  9. Anthropogenic forcings on the surficial osmium cycle.

    PubMed

    Rauch, Sebastien; Peucker-Ehrenbrink, Bernhard; Kylander, Malin E; Weiss, Dominik J; Martinez-Cortizas, Antonio; Heslop, David; Olid, Carolina; Mighall, Tim M; Hemond, Harold F

    2010-02-01

    Osmium is among the least abundant elements in the Earth's continental crust. Recent anthropogenic Os contamination of the environment from mining and smelting activities, automotive catalytic converter use, and hospital discharges has been documented. Here we present evidence for anthropogenic overprinting of the natural Os cycle using a ca. 7000-year record of atmospheric Os deposition and isotopic composition from an ombrotrophic peat bog in NW Spain. Preanthropogenic Os accumulation in this area is 0.10 +/- 0.04 ng m(-2) y(-1). The oldest strata showing human influence correspond to early metal mining and processing on the Iberian Peninsula (ca. 4700-2500 cal. BP). Elevated Os accumulation rates are found thereafter with a local maximum of 1.1 ng m(-2) y(-1) during the Roman occupation of the Iberian Peninsula (ca. 1930 cal. BP) and a further increase starting in 1750 AD with Os accumulation reaching 30 ng m(-2) y(-1) in the most recent samples. Osmium isotopic composition ((187)Os/(188)Os) indicates that recent elevated Os accumulation results from increased input of unradiogenic Os from industrial and automotive sources as well as from enhanced deposition of radiogenic Os through increased fossil fuel combustion and soil erosion. We posit that the rapid increase in catalyst-equipped vehicles, increased fossil fuel combustion, and changes in land-use make the changes observed in NW Spain globally relevant.

  10. Comparison of the Distributions of Bromine, Lead and Zinc in Tooth and Bone from an Ancient Peruvian Burial site by X-ray Fluorescence

    SciTech Connect

    Martin,R.; Naftel, S.; Nelson, A.; Sapp, W.

    2007-01-01

    Synchrotron micro X-ray fluorescence was used to study the distribution of selected trace elements (Zn, Pb, and Br) in tooth and bone samples obtained from an individual from a pre-Columbian archaeological site (Cabur) located on the north coast of Peru. The results show that Zn, Pb, and Br are present in both the teeth and bone samples and that the Zn and Pb seem to be confined to similar regions (cementum and periostium), while Br shows a novel distribution with enrichment close to the Haversian canals and (or) in regions that appear to be Ca deficient.

  11. Checking the concurrence among macrobenthic organism distribution patterns at different taxonomic scales in relation to environmental factors

    NASA Astrophysics Data System (ADS)

    Del-Pilar-Ruso, Yoana; de-la-Ossa-Carretero, Jose Antonio; Giménez-Casalduero, Francisca; Sánchez-Lizaso, José Luis; San Martín, Guillermo

    2014-02-01

    The interaction of both natural conditions and anthropogenic environmental impacts can lead to different soft-bottom macrobenthic distribution patterns. Soft-bottom macrobenthic community was analysed at different taxonomic scales in order to evaluate whether diverse subsets of organisms respond to the variability of the environmental pressures (natural and human induced) showing or not similar distribution patterns. Therefore, this long-term survey had been focused on a heterogeneous area, where both anthropogenic and natural stresses may affect the community. Three perpendicular transects to the coast were established and stations at 4, 10 and 15 m depths were sampled at each transect twice a year (summer-winter) from 2004 to 2009. Non-parametric multivariate techniques were used to analyse soft-bottom macrobenthic community distribution and its relation to the environmental factors. Similar distribution patterns between investigated taxonomic levels were detected and they were mainly related to depth.

  12. Oxidative Stress in Lead and Cadmium Toxicity and Its Amelioration

    PubMed Central

    Patra, R. C.; Rautray, Amiya K.; Swarup, D.

    2011-01-01

    Oxidative stress has been implicated to play a role, at least in part, in pathogenesis of many disease conditions and toxicities in animals. Overproduction of reactive oxygen species and free radicals beyond the cells intrinsic capacity to neutralize following xenobiotics exposure leads to a state of oxidative stress and resultant damages of lipids, protein, and DNA. Lead and cadmium are the common environmental heavy metal pollutants and have widespread distribution. Both natural and anthropogenic sources including mining, smelting, and other industrial processes are responsible for human and animal exposure. These pollutants, many a times, are copollutants leading to concurrent exposure to living beings and resultant synergistic deleterious health effects. Several mechanisms have been explained for the damaging effects on the body system. Of late, oxidative stress has been implicated in the pathogenesis of the lead- and cadmium-induced pathotoxicity. Several ameliorative measures to counteract the oxidative damage to the body system aftermath or during exposure to these toxicants have been assessed with the use of antioxidants. The present review focuses on mechanism of lead- and cadmium-induced oxidate damages and the ameliorative measures to counteract the oxidative damage and pathotoxicity with the use of supplemented antioxidants for their beneficial effects. PMID:21547215

  13. Simulations of the global carbon cycle and anthropogenic CO{sub 2} transient. Final report

    SciTech Connect

    Joos, F.; Stocker, T.

    1996-11-01

    The major emphasis of our DOE funded research was to study the redistribution of anthropogenic carbon in the climate system and to constrain the global budgets of anthropogenic carbon and the carbon isotopes {sup 13}C and {sup 14}C for the historical period. We have continued the development of box models of the ocean carbon cycle (HILDA model) and the land biota. The coupled model (Bern model) was chosen as the reference model for scenario calculations and the calculations of global warming potential by the Intergovernmental Panel on Climate Change. These models were applied (1) to estimate the uptake of anthropogenic carbon by the ocean and the land biosphere for the last 200 years; (2) to investigate uncertainties in deconvolved fertilization fluxes into the land biota due to uncertainties in ice core CO{sub 2} data; (3) to study the relationship between future atmospheric CO{sub 2} levels and carbon emissions; (4) to investigate the budgets of bomb-produced radiocarbon and fossil {sup 13}C. We assessed the utility of bomb-produced and natural {sup 13}C observations to validate ocean models of anthropogenic CO{sub 2} uptake and tested the eddy diffusion parameterization of large-scale vertical transport in ocean box models. For this, vertical tracer transport in box-diffusion models and the 3-D ocean general circulation model from GFDL/Princeton was compared. We analyzed the distribution of the conservative property {Delta}C* to obtain a direct estimate based on marine measurements of the uptake of anthropogenic CO{sub 2} by the North Atlantic. We contribute to the missing sink debate by using atmospheric CO{sub 2} and {sup 13}C levels to disentangle the net carbon fluxes into the land biota and the ocean. A simplified representation for 4 different ocean models of anthropogenic CO{sub 2} uptake based on mixed-layer pulse response functions was developed.

  14. Distributed Leadership: A Good Theory but What if Leaders Won't, Don't Know How, or Can't Lead?

    ERIC Educational Resources Information Center

    McKenzie, Kathryn Bell; Locke, Leslie Ann

    2014-01-01

    This article presents the results from an empirical qualitative study of the challenges faced by teacher leaders in their attempts to work directly with their colleagues to change instructional strategies and improve student success. Additionally, it offers a challenge to the utility of a naïvely espoused theory of distributed leadership, which…

  15. Spatial resolution of subsurface anthropogenic heat fluxes in cities

    NASA Astrophysics Data System (ADS)

    Benz, Susanne; Bayer, Peter; Menberg, Kathrin; Blum, Philipp

    2015-04-01

    Urban heat islands in the subsurface contain large quantities of energy in the form of elevated groundwater temperatures caused by anthropogenic heat fluxes (AHFS) into the subsurface. Hence, the objective of this study is to exemplarily quantify these AHFS and the generated thermal powers in two German cities, Karlsruhe and Cologne. A two-dimensional (2D) statistical analytical model of the vertical subsurface anthropogenic heat fluxes across the unsaturated zone was developed. The model consists of a so-called Local Monte Carlo approach that introduces a spatial representation of the following sources of AHFS: (1) elevated ground surface temperatures, (2) basements, (3) sewage systems, (4) sewage leakage, (5) subway tunnels, and (6) district heating networks. The results show that district heating networks induce the largest local AHFS with values larger than 60 W/m2 and one order of magnitude higher than the other evaluated heat sources. Only sewage pipes and basements reaching into the groundwater cause equally high heat fluxes, with maximal values of 40.37 W/m2 and 13.60 W/m2, respectively. While dominating locally, the district heating network is rather insignificant for the citywide energy budget in both urban subsurfaces. Heat from buildings (1.51 ± 1.36 PJ/a in Karlsruhe; 0.31 ± 0.14 PJ/a in Cologne) and elevated GST (0.34 ± 0.10 PJ/a in Karlsruhe; 0.42 ± 0.13 PJ/a in Cologne) are dominant contributors to the anthropogenic thermal power of the urban aquifer. In Karlsruhe, buildings are the source of 70% of the annual heat transported into the groundwater, which is mainly caused by basements reaching into the groundwater. A variance analysis confirms these findings: basement depth is the most influential factor to citywide thermal power in the studied cities with high groundwater levels. The spatial distribution of fluxes, however, is mostly influenced by the prevailing thermal gradient across the unsaturated zone. A relatively cold groundwater

  16. LEAD STUDIES

    PubMed Central

    Aub, Joseph C.; Reznikoff, Paul; Smith, Dorothea E.

    1924-01-01

    It appears, from the investigations in other laboratories, that the anemia observed in cases of lead poisoning is due to destruction of blood rather than to diminished production of blood. The method of poisoning cells in vitro with lead was adopted in order to study this phenomenon, and distinct effects were thereby obtained, even when only 0.001 mg. of lead is added to approximately 5 billion washed red corpuscles. In order to obtain optimum results the usual dosage employed was ten times this or 0.01 mg. per 5 billion cells. The following changes were observed in cells so treated. 1. Such a marked increase in the resistance to hypotonic salt solution develops that complete hemolysis does not occur until the cells are exposed to a saline solution of 0.05 per cent. Untreated cells are completely hemolyzed in 0.25 or 0.225 per cent saline. 2. This reaction is quantitative and varies with the concentration of lead used. Under the conditions of our experiments this phenomenon seems to be unique. The effects of arsenic are very slight in comparison. 3. While from this reaction it may be concluded that lead increases cellular resistance, it also appears that it shortens the life of blood cells. This may be demonstrated by the much more rapid appearance of hemolysis than normal when the cells are merely allowed to stand in Ringer solution of any dilution. 4. In rabbits with acute lead poisoning these same phenomena may be noted in vivo. 5. Both phenomena may be changed in vitro by varying the time and temperature of the reaction and the concentration of lead, as Fici has already pointed out. 6. If normal cells stand in Ringer solution for 6 hours something diffuses into the solution which largely reduces the action of lead. After repeated washing these cells react with lead in the usual manner. 7. Small amounts of serum react with lead and eliminate its effects. Red blood cells, treated with a mixture of lead and blood serum, show normal hemolysis in hypotonic salt

  17. Contribution of anthropogenic and natural sources to atmospheric methane variability.

    PubMed

    Bousquet, P; Ciais, P; Miller, J B; Dlugokencky, E J; Hauglustaine, D A; Prigent, C; Van der Werf, G R; Peylin, P; Brunke, E-G; Carouge, C; Langenfelds, R L; Lathière, J; Papa, F; Ramonet, M; Schmidt, M; Steele, L P; Tyler, S C; White, J

    2006-09-28

    Methane is an important greenhouse gas, and its atmospheric concentration has nearly tripled since pre-industrial times. The growth rate of atmospheric methane is determined by the balance between surface emissions and photochemical destruction by the hydroxyl radical, the major atmospheric oxidant. Remarkably, this growth rate has decreased markedly since the early 1990s, and the level of methane has remained relatively constant since 1999, leading to a downward revision of its projected influence on global temperatures. Large fluctuations in the growth rate of atmospheric methane are also observed from one year to the next, but their causes remain uncertain. Here we quantify the processes that controlled variations in methane emissions between 1984 and 2003 using an inversion model of atmospheric transport and chemistry. Our results indicate that wetland emissions dominated the inter-annual variability of methane sources, whereas fire emissions played a smaller role, except during the 1997-1998 El Niño event. These top-down estimates of changes in wetland and fire emissions are in good agreement with independent estimates based on remote sensing information and biogeochemical models. On longer timescales, our results show that the decrease in atmospheric methane growth during the 1990s was caused by a decline in anthropogenic emissions. Since 1999, however, they indicate that anthropogenic emissions of methane have risen again. The effect of this increase on the growth rate of atmospheric methane has been masked by a coincident decrease in wetland emissions, but atmospheric methane levels may increase in the near future if wetland emissions return to their mean 1990s levels.

  18. Biogenic carbon and anthropogenic pollutants combine to form a cooling haze over the southeastern United States

    PubMed Central

    Goldstein, Allen H.; Koven, Charles D.; Heald, Colette L.; Fung, Inez Y.

    2009-01-01

    Remote sensing data over North America document the ubiquity of secondary aerosols resulting from a combination of primary biogenic and anthropogenic emissions. The spatial and temporal distribution of aerosol optical thickness (AOT) over the southeastern United States cannot be explained by anthropogenic aerosols alone, but is consistent with the spatial distribution, seasonal distribution, and temperature dependence of natural biogenic volatile organic compound (BVOC) emissions. These patterns, together with observations of organic aerosol in this region being dominated by modern 14C and BVOC oxidation products with summer maxima, indicate nonfossil fuel origins and strongly suggest that the dominant summer AOT signal is caused by secondary aerosol formed from BVOC oxidation. A link between anthropogenic and biogenic emissions forming secondary aerosols that dominate the regional AOT is supported by reports of chemicals in aerosols formed by BVOC oxidation in a NOx- and sulfate-rich environment. Even though ground-based measurements from the IMPROVE network suggest higher sulfate than organic concentrations near the surface in this region, we infer that much of the secondary organic aerosol in the Southeast must occur above the surface layer, consistent with reported observations of the organic fraction of the total aerosol increasing with height and models of the expected vertical distribution of secondary organic aerosols from isoprene oxidation. The observed AOT is large enough in summer to provide regional cooling; thus we conclude that this secondary aerosol source is climatically relevant with significant potential for a regional negative climate feedback as BVOC emissions increase with temperature. PMID:19451635

  19. Elevated lead and zinc contents in remote alpine soils of the Swiss National Park.

    PubMed

    Nowack, B; Obrecht, J M; Schluep, M; Schulin, R; Hansmann, W; Köppel, V

    2001-01-01

    Weathering of bedrock and pedogenic processes can result in elevated heavy metal concentrations in the soil. Small-scale variations in bedrock composition can therefore cause local variations in the metal content of the soil. Such a case was found in the remote alpine area of the Swiss National Park. Soil profiles were sampled at an altitude of about 2,400 m, representing soils developed above different bedrocks. The concentration of lead in the profiles was found to be strongly dependent on the metal content in the bedrock underlying the soil and was strongly enriched in the top 10 cm. The dolomitic bedrock in the study area contains elevated lead concentrations compared with other dolomites. Dissolution of dolomite and accumulation of weathering residues during soil formation resulted in high lead concentrations throughout the soil profile. The enrichment of lead in the topsoil, however, is largely attributed to atmospheric input. The isotopic signature of the lead clearly indicates that it is mainly of natural origin and that atmospheric deposition of anthropogenic lead contributed to about 20 to 40% to the lead concentration in the topsoil on the bedrock with elevated lead concentrations. In the soils on bedrock with normal lead concentrations, the anthropogenic contribution is estimated to be about 75%. Also, zinc was very strongly enriched in the topsoil. This enrichment was closely correlated with the organic matter distribution in the profiles, suggesting that recycling through plant uptake and litter deposition was a dominant process in the long-term retention of this metal in the soil.

  20. Contaminant distributions near Chernobyl: Cesium, lead and mercury in fish and sediments from ponds upwind and downwind of the accident site

    SciTech Connect

    Jagoe, C.H.; Chesser, R.K.; Dallas, C.E.; Smith, M.H.

    1995-12-31

    The distribution of contaminants near Chernobyl is extremely patchy, and was highly influenced by prevailing wind direction after the accident. In data from Soviet agencies and their successors, regions to the south and southeast or the reactor reportedly received much less radioactivity than regions in the north and northwest. We visited sites to the south of Chernobyl in 1992, and to the north in 1993; all sites were within 35 km of the power plant. Sediments and fish samples from about 20 ponds were analyzed for radiocesium; Pb and Hg were also determined in fish muscle. Lake sediments in the south contained 0.02 to 11 Bq/g {sup 137}Cs, while those to the north contained up to 2000 Bq/g {sup 137}Cs. Fish muscle also contained much less radioactivity in southern areas ({le} 8.2 Bq/g vs. {le} 212 Bq/g at northern sites). Pb and Hg were elevated in some samples, but the distribution of radioactive and non-radioactive contaminants were not highly correlated. Low ionic strength waters typically favor contaminant uptake; waters in the area were soft (sp. cond < 450 {mu}S/cm) and low in Ca and K. In these regions, water chemistry was a poor predictor of fish contaminant burden, possibly due to the extreme patchiness of the contaminant distribution. Human habitation is presently permitted in the southern regions we visited, but the northern ones. A companion poster has been submitted detailing measurements of genetic anomalies in these fish.

  1. Characterizing ultrafine particle growth at a pine forest site influenced by anthropogenic pollution during BEACHON-RoMBAS-2011

    NASA Astrophysics Data System (ADS)

    Cui, Y.; Hodzic, A.; Smith, J. N.; Ortega, J. V.; de Foy, B.

    2013-12-01

    Representing the formation and growth of ultrafine particles in chemistry and climate models is challenging due to the complexity of processes involved, which leads to uncertainties in aerosol size distributions and their effects on Cloud Condensation Nuclei (CCN). The Rocky Mountain Biogenic Aerosol Study (RoMBAS) was an intensive measurement campaign as part of the broader BEACHON (Bio-hydro-atmosphere interactions of Energy Aerosols, Carbon, H2O, Organics and Nitrogen) project. This took place during July - August 2011 at the Manitou Experimental Forest Observatory. The location is situated in the rural-urban interface along the Colorado Front Range and allows us to study the effects of aerosol formation and other atmospheric chemistry phenomenon in a forested region with periodic urban influences. Surface measurements of gases, aerosols and meteorological parameters from this campaign were used to examine the formation and growth processes leading to observed Aiken-mode Particle burst Events (APEs), and to quantify their effects on aerosol properties and cloud condensation nuclei CCN concentrations. Results suggest that APEs were observed at the forest site in the early afternoon associated with the arrival of anthropogenic plumes from Denver and Colorado Springs. Mean number concentrations of ultrafine particles (4-30nm) typically exceeded 5000 cm-3 during APEs and these elevated concentrations were correlated with elevated SO2. The Weather Research and Forecasting model with on-line Chemistry (WRF-Chem) was used to model APEs during BEACHON-RoMBAS. The model was updated to include an activation nucleation (AN) scheme with an empirical representation of aerosol nucleation rate, and subsequent growth due to the condensation of organic and inorganic vapors. Comparisons with ground measurements show that the updated model reasonably captures aerosol number concentrations and size distribution during APEs, as well as CN and CCN concentrations. Model results

  2. Change in diurnal variations of meteorological variables induced by anthropogenic aerosols over the North China Plain

    NASA Astrophysics Data System (ADS)

    Zhang, Meigen; Gao, Yi; Liu, Xiaohong; Wang, Lili

    2016-04-01

    This study investigates the impacts of all anthropogenic aerosols and anthropogenic black carbon (BC) on the diurnal variations of meteorological variables in the atmospheric boundary layer over the North China Plain (NCP) during June to August 2008, using a coupled meteorology and chemistry model (WRF-Chem). The results of the ensemble numerical experiments show that surface air temperature decreases by about 0.6 to 1.2 K with the maximum decrease over the Beijing urban area and the southern part of Hebei province, and the surface relative humidity (RH) increases by 2-4 % owing to all anthropogenic aerosols. On the contrary, anthropogenic BC induces a small change of temperature and RH at surface. Averaged for Beijing, Tianjin, and Hebei province (BTH region) and High Particle Concentration (HPC) periods when PM2.5 surface concentration is more than 60 μg m-3 and daily AOD is more than 0.9, all anthropogenic aerosols decrease air temperature under 850 hPa and increase it between 500 and 850 hPa, while anthropogenic BC increases it for whole atmosphere. The maximum changes occur at 08:00-20:00 (local time). Aerosol-induced surface energy and diabatic heating change leads to a cooling at the surface and in the lower atmosphere and a warming in the middle troposphere at 08:00-17:00, with reversed effects at 20:00-05:00. BC cools the atmosphere at the surface and warms the atmosphere above for the whole day. As a result, the equivalent potential temperature profile change shows that the lower atmosphere is more stable at 08:00 and 14:00. All anthropogenic aerosols decrease the surface wind speed by 20-60 %, while anthropogenic BC decreases the wind speed by 10-40 % over the NCP with the maximum decrease at 08:00. The aerosol-induced stabilization of the lower atmosphere favors the accumulation of air pollutants and thus contributes to deterioration of visibility and fog-haze events.

  3. Change in diurnal variations of meteorological variables induced by anthropogenic aerosols over the North China Plain

    NASA Astrophysics Data System (ADS)

    Zhang, Meigen; Gao, Yi; Liu, Xiaohong; Wang, Lili

    2016-04-01

    This study investigates the impacts of all anthropogenic aerosols and anthropogenic black carbon (BC) on the diurnal variations of meteorological variables in the atmospheric boundary layer over the North China Plain (NCP) during June to August 2008, using a coupled meteorology and chemistry model (WRF-Chem). The results of the ensemble numerical experiments show that surface air temperature decreases by about 0.6 to 1.2 K with the maximum decrease over the Beijing urban area and the southern part of Hebei province, and the surface relative humidity (RH) increases by 2-4 % owing to all anthropogenic aerosols. On the contrary, anthropogenic BC induces a small change of temperature and RH at surface. Averaged for Beijing, Tianjin, and Hebei province (BTH region) and High Particle Concentration (HPC) periods when PM2.5 surface concentration is more than 60 μg m‑3 and daily AOD is more than 0.9, all anthropogenic aerosols decrease air temperature under 850 hPa and increase it between 500 and 850 hPa, while anthropogenic BC increases it for whole atmosphere. The maximum changes occur at 08:00-20:00 (local time). Aerosol-induced surface energy and diabatic heating change leads to a cooling at the surface and in the lower atmosphere and a warming in the middle troposphere at 08:00-17:00, with reversed effects at 20:00-05:00. BC cools the atmosphere at the surface and warms the atmosphere above for the whole day. As a result, the equivalent potential temperature profile change shows that the lower atmosphere is more stable at 08:00 and 14:00. All anthropogenic aerosols decrease the surface wind speed by 20-60 %, while anthropogenic BC decreases the wind speed by 10-40 % over the NCP with the maximum decrease at 08:00. The aerosol-induced stabilization of the lower atmosphere favors the accumulation of air pollutants and thus contributes to deterioration of visibility and fog-haze events.

  4. Modeling ultrafine particle growth at a pine forest site influenced by anthropogenic pollution during BEACHON-RoMBAS 2011

    NASA Astrophysics Data System (ADS)

    Cui, Y. Y.; Hodzic, A.; Smith, J. N.; Ortega, J.; Brioude, J.; Matsui, H.; Turnipseed, A.; Winkler, P.; de Foy, B.

    2014-03-01

    Formation and growth of ultrafine particles is crudely represented in chemistry-climate models, which contributes to uncertainties in aerosol composition, size distribution, and aerosol effects on cloud condensation nuclei (CCN) concentrations. Measurements of ultrafine particles, their precursor gases, and meteorological parameters were performed in a ponderosa pine forest in the Colorado Front Range in July-August 2011, and were analyzed to study processes leading to Aitken-mode Particle burst Events (APEs). These measurements suggest that APEs were associated with the arrival at the site of anthropogenic pollution plumes around noon or in the early afternoon. Number concentrations of ultrafine (4 to 30 nm diameter) particles typically exceeded 10 000 cm-3 during APEs, and these elevated concentrations coincided with increased SO2 and monoterpene concentrations, and led to a factor of two increase in CCN concentrations at 0.5% supersaturation. The APEs were simulated using the regional WRF-Chem model, which was extended to account for ultrafine particle sizes starting at 1 nm in diameter, to include an empirical activation nucleation scheme in the planetary boundary layer, and to explicitly simulate the subsequent growth of Aitken particles by condensation of organic and inorganic vapors. Comparisons with aerosol size distribution measurements showed that simulations using the activation nucleation parameterization reasonably captured aerosol number concentrations and size distribution during APEs, as well as ground level CCN concentrations. Results suggest that sulfuric acid from anthropogenic SO2 triggers APEs, and that the condensation of monoterpene oxidation products onto freshly nucleated particles drives their growth. The simulated growth rate of 3.4 nm h-1 for small particles (4-30 nm in diameter) was comparable to the measured average value of 2.3 nm h-1. Model results also suggest that the presence of APEs tends to modify the composition of sub-100 nm

  5. Anthropogenic Sulfur Dioxide Emissions: 1850-2005

    SciTech Connect

    Smith, Steven J.; van Aardenne, John; Klimont, Z.; Andres, Robert; Volke, April C.; Delgado Arias, Sabrina

    2011-01-02

    Sulfur aerosols impact human health, ecosystems, agriculture, and global and regional climate. A new annual estimate of anthropogenic global and regional sulfur dioxide emissions has been constructed spanning the period 1850 - 2005. A combination of mass balance and best available inventory data was used in order to achieve the most accurate estimate possible. Global emissions peaked in the early 1970s and decreased until 2000, with an increase in recent years due to increased emissions in China, international shipping, and developing countries in general. An uncertainty analysis was conducted including both random and systemic uncertainties. The overall global uncertainty in sulfur dioxide emissions is relatively small, but regional uncertainties of up to 30% were found. The largest contributors to uncertainty at present are emissions from China and international shipping.

  6. Anthropogenic noise increases fish mortality by predation

    PubMed Central

    Simpson, Stephen D.; Radford, Andrew N.; Nedelec, Sophie L.; Ferrari, Maud C. O.; Chivers, Douglas P.; McCormick, Mark I.; Meekan, Mark G.

    2016-01-01

    Noise-generating human activities affect hearing, communication and movement in terrestrial and aquatic animals, but direct evidence for impacts on survival is rare. We examined effects of motorboat noise on post-settlement survival and physiology of a prey fish species and its performance when exposed to predators. Both playback of motorboat noise and direct disturbance by motorboats elevated metabolic rate in Ambon damselfish (Pomacentrus amboinensis), which when stressed by motorboat noise responded less often and less rapidly to simulated predatory strikes. Prey were captured more readily by their natural predator (dusky dottyback, Pseudochromis fuscus) during exposure to motorboat noise compared with ambient conditions, and more than twice as many prey were consumed by the predator in field experiments when motorboats were passing. Our study suggests that a common source of noise in the marine environment has the potential to impact fish demography, highlighting the need to include anthropogenic noise in management plans. PMID:26847493

  7. Anthropogenic signals in Iranian extreme temperature indices

    NASA Astrophysics Data System (ADS)

    Balling, Robert C.; Kiany, Mohammad Sadegh Keikhosravi; Roy, Shouraseni Sen

    2016-03-01

    We analyzed spatial and temporal patterns in temperature extremes from 31 stations located throughout Iran for the period 1961 to 2010. As with many other parts of the globe, we found that the number of days (a) with high maximum temperatures was rising, (b) with high minimum temperatures was rising, and (c) with low minimum temperatures was declining; all of these trends were statistically significant at the 0.05 level of confidence. Population records from 1956 to 2011 at the station locations allowed us to reveal that the rate of human population growth was positively related to the increase in the number of days with high maximum temperatures and negatively related to days with low maximum temperatures. Our research shows a number of identifiable anthropogenic signals in the temperature records from Iran, but unlike most other studies, the signals are stronger with indices related to maximum, not minimum, temperatures.

  8. Anthropogenic enhancement of Egypt's Mediterranean fishery

    PubMed Central

    Oczkowski, Autumn J.; Nixon, Scott W.; Granger, Stephen L.; El-Sayed, Abdel-Fattah M.; McKinney, Richard A.

    2009-01-01

    The highly productive coastal Mediterranean fishery off the Nile River delta collapsed after the completion of the Aswan High Dam in 1965. But the fishery has been recovering dramatically since the mid-1980s, coincident with large increases in fertilizer application and sewage discharge in Egypt. We use stable isotopes of nitrogen (δ15N) to demonstrate that 60%–100% of the current fishery production may be from primary production stimulated by nutrients from fertilizer and sewage runoff. Although the establishment of the dam put Egypt in an ideal position to observe the impact of rapid increases in nutrient loading on coastal productivity in an extremely oligotrophic sea, the Egyptian situation is not unique. Such anthropogenically enhanced fisheries also may occur along the northern rim of the Mediterranean and offshore of some rapidly developing tropical countries, where nutrient concentrations in the coastal waters were previously very low. PMID:19164510

  9. Anthropogenic signals in Iranian extreme temperature indices

    NASA Astrophysics Data System (ADS)

    Balling, Robert; Kiany, Mohammad; Roy, Shouraseni Sen

    2016-04-01

    Studies from throughout the world indicate that maximum and minimum temperatures are rising during the period of historical records; urbanization has contributed to some extent to these increases. In this investigation, we analyzed patterns in temperature extremes for stations located throughout Iran. We found that the number of days (a) with high maximum temperatures was increasing, (b) with high minimum temperatures was rising, and (c) with low minimum temperatures is declining. Based on population records at the station locations, we found that population growth was positively related to the increase the number of days with high maximum temperatures and negatively related to days with low maximum temperatures. A day-of-the-week signal also appeared in the number of days with high maximum temperatures. Our research shows a number of identifiable and statistically significant anthropogenic signals in the temperature records from Iran, but unlike most other studies, the signals are stronger with indices related to maximum, not minimum, temperatures.

  10. Anthropogenic noise increases fish mortality by predation.

    PubMed

    Simpson, Stephen D; Radford, Andrew N; Nedelec, Sophie L; Ferrari, Maud C O; Chivers, Douglas P; McCormick, Mark I; Meekan, Mark G

    2016-01-01

    Noise-generating human activities affect hearing, communication and movement in terrestrial and aquatic animals, but direct evidence for impacts on survival is rare. We examined effects of motorboat noise on post-settlement survival and physiology of a prey fish species and its performance when exposed to predators. Both playback of motorboat noise and direct disturbance by motorboats elevated metabolic rate in Ambon damselfish (Pomacentrus amboinensis), which when stressed by motorboat noise responded less often and less rapidly to simulated predatory strikes. Prey were captured more readily by their natural predator (dusky dottyback, Pseudochromis fuscus) during exposure to motorboat noise compared with ambient conditions, and more than twice as many prey were consumed by the predator in field experiments when motorboats were passing. Our study suggests that a common source of noise in the marine environment has the potential to impact fish demography, highlighting the need to include anthropogenic noise in management plans. PMID:26847493

  11. Anthropogenic disturbances are key to maintaining the biodiversity of grasslands

    PubMed Central

    Yuan, Z. Y.; Jiao, F.; Li, Y. H.; Kallenbach, Robert L.

    2016-01-01

    Although anthropogenic disturbances are often perceived as detrimental to plant biodiversity, the relationship between biodiversity and disturbance remains unclear. Opinions diverge on how natural diversity is generated and maintained. We conducted a large-scale investigation of a temperate grassland system in Inner Mongolia and assessed the richness-disturbance relationship using grazing intensity, the primary anthropogenic disturbance in the region. Vascular plant-species richness peaked at an intermediate level of anthropogenic disturbance. Our results support the Intermediate Disturbance Hypothesis, which provides a valid and useful measure of biodiversity at a metacommunity scale, indicating that anthropogenic disturbances are necessary to conserve the biodiversity of grassland systems. PMID:26903041

  12. Tracking Public Beliefs About Anthropogenic Climate Change.

    PubMed

    Hamilton, Lawrence C; Hartter, Joel; Lemcke-Stampone, Mary; Moore, David W; Safford, Thomas G

    2015-01-01

    A simple question about climate change, with one choice designed to match consensus statements by scientists, was asked on 35 US nationwide, single-state or regional surveys from 2010 to 2015. Analysis of these data (over 28,000 interviews) yields robust and exceptionally well replicated findings on public beliefs about anthropogenic climate change, including regional variations, change over time, demographic bases, and the interacting effects of respondent education and political views. We find that more than half of the US public accepts the scientific consensus that climate change is happening now, caused mainly by huma