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Low concentrations, potential ecological consequences: Synthetic estrogens alter life-history and demographic structures of aquatic invertebrates
2013
Souza, María Sol | Hallgren, Per | Balseiro, Esteban | Hansson, Lars-Anders
Contraceptive drugs are nowadays found in aquatic environments around the globe. Particularly, 17α-ethinylestradiol (EE2) may act even at low concentrations, such as those recorded in natural ecosystems. We evaluated the physiological effects of EE2 on cyclopoids and calanoids, common copepods in both marine and freshwater communities. We used three EE2 concentrations and assessed its impact on activity of different physiological endpoints: Acetylcholinesterase (neurotransmission), Glutathione S-transferase (detoxifying system), and Caspase-3 (apoptosis). While EE2 exerts, distinctive effect on detoxifying and apoptotic systems, no effect on AChE was observed at environmental doses. Our results show that EE2 exposure affects differently copepod physiology endpoints, altering moulting process, adult recruitment in calanoids and calanoid to cyclopoid ratio. The ecological consequences of this underlying physiological process may affect since life history to population and community structures, and this represent a new aspects of this xenobiotic in natural systems.
Show more [+] Less [-]Modelling the effects of copper on soil organisms and processes using the free ion approach: Towards a multi-species toxicity model
2013
Lofts, Stephen | Criel, Peggy | Janssen, Colin R. | Lock, Koen | McGrath, Steve P. | Oorts, Koen | Rooney, Corinne P. | Smolders, Erik | Spurgeon, David J. | Svendsen, Claus | Van Eeckhout, Hilde | Zhao, Fang-Zie
The free ion approach has been previously used to calculate critical limit concentrations for soil metals based on point estimates of toxicity. Here, the approach was applied to dose–response data for copper effects on seven biological endpoints in each of 19 European soils. The approach was applied using the concept of an effective dose, comprising a function of the concentrations of free copper and ‘protective’ major cations, including H+. A significant influence of H+ on the toxicity of Cu2+ was found, while the effects of other cations were inconsistent. The model could be generalised by forcing the effect of H+ and the slope of the dose–response relationship to be equal for all endpoints. This suggests the possibility of a general bioavailability model for copper effects on organisms. Furthermore, the possibility of such a model could be explored for other cationic metals such as nickel, zinc, cadmium and lead.
Show more [+] Less [-]Lead bioaccessibility in topsoils from lead mineralisation and urban domains, UK
2013
Appleton, J.D. | Cave, M.R. | Palumbo-Roe, B. | Wragg, J.
Predictive linear regression (LR) modelling indicates that total Pb is the only highly significant independent variable for estimating Pb bioaccessibility in “mineralisation domains” located in limestone (high pH) and partly peat covered (low pH) shale-sandstone terrains in England. Manganese is a significant minor predictor in the limestone terrain, whilst organic matter and sulphur explain 0.5% and 2% of the variance of bioaccessible Pb in the peat-shale-sandstone terrain, compared with 93% explained by total Pb. Bootstrap resampling shows that LR confidence limits overlap for the two mineralised terrains but the limestone terrain has a significantly lower bioaccessible Pb to total Pb slope than the urban domain. A comparison of the absolute values of stomach and combined stomach-intestine bioaccessibility provides some insight into the geochemical controls on bioaccessibility in the contrasting soil types.
Show more [+] Less [-]Environmental concentrations of engineered nanomaterials: Review of modeling and analytical studies
2013
Gottschalk, Fadri | Sun, TianYin | Nowack, Bernd
Scientific consensus predicts that the worldwide use of engineered nanomaterials (ENM) leads to their release into the environment. We reviewed the available literature concerning environmental concentrations of six ENMs (TiO2, ZnO, Ag, fullerenes, CNT and CeO2) in surface waters, wastewater treatment plant effluents, biosolids, sediments, soils and air. Presently, a dozen modeling studies provide environmental concentrations for ENM and a handful of analytical works can be used as basis for a preliminary validation. There are still major knowledge gaps (e.g. on ENM production, application and release) that affect the modeled values, but over all an agreement on the order of magnitude of the environmental concentrations can be reached. True validation of the modeled values is difficult because trace analytical methods that are specific for ENM detection and quantification are not available. The modeled and measured results are not always comparable due to the different forms and sizes of particles that these two approaches target.
Show more [+] Less [-]Distributions, sources and pollution status of 17 trace metal/metalloids in the street dust of a heavily industrialized city of central China
2013
Li, Zhonggen | Feng, Xinbin | Li, Guanghui | Bi, Xiangyang | Zhu, Jianming | Qin, Haibo | Dai, Zhihui | Liu, Jinling | Li, Qiuhua | Sun, Guangyi
A series of representative street dust samples were collected from a heavily industrialized city, Zhuzhou, in central China, with the aim to investigate the spatial distribution and pollution status of 17 trace metal/metalloid elements. Concentrations of twelve elements (Pb, Zn, Cu, Cd, Hg, As, Sb, In, Bi, Tl, Ag and Ga) were distinctly amplified by atmospheric deposition resulting from a large scale Pb/Zn smelter located in the northwest fringe of the city, and followed a declining trend towards the city center. Three metals (W, Mo and Co) were enriched in samples very close to a hard alloy manufacturing plant, while Ni and Cr appeared to derive predominantly from natural sources. Other industries and traffic had neglectable effects on the accumulation of observed elements. Cd, In, Zn, Ag and Pb were the five metal/metalloids with highest pollution levels and the northwestern part of city is especially affected by heavy metal pollution.
Show more [+] Less [-]Characterization and influence of biochars on nitrous oxide emission from agricultural soil
2013
Wang, Zhenyu | Zheng, Hao | Luo, Ye | Deng, Xia | Herbert, Stephen | Xing, Baoshan
Extensive use of biochar to mitigate N2O emission is limited by the lack of understanding on the exact mechanisms altering N2O emissions from biochar-amended soils. Biochars produced from giant reed were characterized and used to investigate their influence on N2O emission. Responses of N2O emission varied with pyrolysis temperature, and the reduction order of N2O emission by biochar (BC) was: BC200 ≈ BC600 > BC500 ≈ BC300 ≈ BC350 > BC400. The reduced emission was attributed to enhanced N immobilization and decreased denitrification in the biochar-amended soils. The remaining polycyclic aromatic hydrocarbons (PAHs) in low-temperature biochars (300–400 °C) played a major role in reducing N2O emission, but not for high-temperature biochars (500–600 °C). Removal of phenolic compounds from low-temperature (200–400 °C) biochars resulted in a surprising reduction of N2O emission, but the mechanism is still unknown. Overall, adding giant reed biochars could reduce N2O evolution from agricultural soil, thus possibly mitigating global warming.
Show more [+] Less [-]Assessment of exposure to heavy metals and health risks among residents near abandoned metal mines in Goseong, Korea
2013
Ji, Kyunghee | Kim, Jungkon | Lee, Minjung | Park, Soyoung | Kwon, Ho-Jang | Cheong, Hae-Kwan | Jang, Jae-Yeon | Kim, Dae-Seon | Yu, Seungdo | Kim, Young Wook | Lee, Kwang-Young | Yang, Seoung-Oh | Jhung, Ik Jae | Yang, Won-Ho | Paek, Do-Hyun | Hong, Yun-Chul | Choi, Kyungho
Metal contamination from mining activity is of great concern because of potential health risks to the local inhabitants. In the present study, we investigated the levels of Cd, Cu, As, Pb, and Zn in environmental samples and foodstuffs grown in the vicinity of the mines in Goseong, Korea, and evaluated potential health risks among local residents. Soils near the mines exceeded the soil quality standard values of Cu, As, and Zn contamination. The concentrations of Cd, Cu, Pb, and Zn in crop samples collected from the study area were significantly higher than those of the reference area. Some rice samples collected from the study area exceeded the maximum permissible level of 0.2 mg Cd/kg. The intake of rice was identified as a major contributor (≥75%) to the estimated daily intake among the residents. The average estimated daily intakes of metals were, however, below the provisional tolerable daily intake.
Show more [+] Less [-]Associations of particulate air pollution and daily mortality in 16 Chinese cities: An improved effect estimate after accounting for the indoor exposure to particles of outdoor origin
2013
Chen, Renjie | Zhou, Bin | Kan, Haidong | Zhao, Bin
People typically spend most of their time indoors. We modeled the daily indoor PM10 concentrations of outdoor origin using a set of exposure parameters, including the fraction of residences with air conditionings (AC), the fraction of time that windows are closed when cooling occurs for buildings with AC, the fractions of time that windows are open or closed for buildings with or without AC, the particle penetration factors, air change rates, and surface removal rate constant of PM10. We calculated the time-weighted average of the simulated indoor PM10 concentration of outdoor origin and the original recorded outdoor PM10 concentration. We then evaluated the acute effects of PM10 using traditional and amended exposure metrics in 16 Chinese cities. Compared with the original estimates, the new effect estimates almost doubled, with improved model fit and attenuated between-city heterogeneity. Conclusively, this proposed exposure assessment approach could improve the effect estimates of ambient particles.
Show more [+] Less [-]Trophodynamics of inorganic pollutants in a wide-range feeder: The relevance of dietary inputs and biomagnification in the Yellow-legged gull (Larus michahellis)
2013
Ramos, Raúl | Ramirez, Francisco | Jover, Lluís
The suitability of sentinel species to monitor environmental pollution is often hampered by an insufficient knowledge on pollutant trophodynamics. We simultaneously evaluated the influence of individuals' trophic position (as revealed by δ15N values) and dietary exploitation of particular systems (using δ13C and δ34S as proxies) on inorganic pollutant concentrations measured on fledglings' feathers of a wide-range feeder, the Yellow-legged Gull (Larus michahellis), sampled at four locations throughout the Western Mediterranean. Concentrations of total Hg and Se in fledgling feathers (2.43 ± 1.30 and 1.16 ± 0.43 μg/g, respectively) were under the threshold points for deleterious effects on seabirds. On the contrary, alarming Pb concentrations were found in one colony (mean: 1.57 ± 2.46 μg/g, range: 0.16–12.13). With the exception of Pb, pollutant concentrations were positively influenced by consumption of marine resources (as suggested by the positive relationship with δ34S values), whereas trophic position played a minor role in determining pollutant body burdens.
Show more [+] Less [-]Differential effects of oxidised and reduced nitrogen on vegetation and soil chemistry of species-rich acidic grasslands
2013
Dorland, Edu | Stevens, Carly J. | Gaudnik, Cassandre | Corcket, Emmanuel | Rotthier, Suzanne | Wotherspoon, Katherine | Jokerud, Mari | Vandvik, Vigdis | Soons, Merel B. | Hefting, Mariet M. | Aarrestad, Per Arild | Alard, Didier | Diekmann, Martin | Dupre, Cecilia | Dise, Nancy B. | Gowing, David J. G. | Bobbink, Roland | Research Institute | Lancaster Environment Centre ; Lancaster University | Biodiversité, Gènes & Communautés (BioGeCo) ; Institut National de la Recherche Agronomique (INRA)-Université de Bordeaux (UB) | Nature Conservation and Plant Ecology Group ; Wageningen University and Research [Wageningen] (WUR) | Open University | University of Bergen (UiB) | Universiteit Utrecht / Utrecht University [Utrecht] | Norwegian Institute for Nature Research (NINA) | Universität Bremen [Deutschland] = University of Bremen [Germany] = Université de Brême [Allemagne] | School of Science and the Environment ; Manchester Metropolitan University (MMU) | Radboud University [Nijmegen]
International audience | Emissions and deposition of ammonia and nitrogen oxides have strongly increased since the 1950s. This has led to significant changes in the nitrogen (N) cycle, vegetation composition and plant diversity in many ecosystems of high conservation value in Europe. As a consequence of different regional pollution levels and of the increased importance of reduced N in the near future, determining the effect of different forms of N is an important task for understanding the consequences of atmospheric N inputs. We have initiated three replicated N addition experiments in species-rich, acidic grasslands spanning a climatic gradient in the Atlantic biogeographic region of Europe in Norway, Wales and France at sites with low levels of pollution. N was added in two doses (0 and 70 kg N ha−1 year−1 above background) and in three forms (oxidised N, reduced N and a 50–50 combination). After 2.5 years of N additions, the effects of these treatments on plant biomass, plant nutritional status, soil pH and soil nutrient availability were determined. Impacts of the N additions were observed within the 2.5-year research period. In some cases, the first signs of differential effects of N form could also be demonstrated. In the French site, for example, grass biomass was significantly increased by the oxidised N treatments but decreased by the reduced N treatments. In the Norwegian site, the reduced N treatments significantly reduced soil pH, whereas oxidised N did not. Effects on nutrient availability were also observed. These experiments will be continued to elucidate the longer term impacts of N deposition on these grasslands.
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