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Life stage-specific effects of the fungicide pyrimethanil and temperature on the snail Physella acuta (Draparnaud, 1805) disclose the pitfalls for the aquatic risk assessment under global climate change Full text
2013
Seeland, Anne | Albrand, Jennifer | Oehlmann, Jörg | Müller, Ruth
It can be suggested that the combined stress of pesticide pollution and suboptimal temperature influences the sensitivity of life stages of aquatic invertebrates differently.The embryo, juvenile, half- and full-life-cycle toxicity tests performed with the snail Physella acuta at different concentrations (0.06–0.5 or 1.0 mg L−1) of the model fungicide pyrimethanil at 15, 20 and 25 °C revealed, that pyrimethanil caused concentration-dependent effects at all test temperatures. Interestingly, the ecotoxicity of pyrimethanil was higher at lower (suboptimal) temperature for embryo hatching and F1 reproduction, but its ecotoxicity for juvenile growth and F0 reproduction increased with increasing temperature.The life-stage specific temperature-dependent ecotoxicity of pyrimethanil and the high fungicide susceptibility of the invasive snail clearly demonstrate the complexity of pesticide–temperature interactions and the challenge to draw conclusions for the risk of pesticides under the impact of global climate change.
Show more [+] Less [-]Distribution and speciation of metals (Cu, Zn, Cd, and Pb) in agricultural and non-agricultural soils near a stream upriver from the Pearl River, China Full text
2013
Yang, Silin | Zhou, Dequn | Yu, Huayong | Wei, Rong | Pan, Bo
The distribution and chemical speciation of typical metals (Cu, Zn, Cd and Pb) in agricultural and non-agricultural soils were investigated in the area of Nanpan River, upstream of the Pearl River. The investigated four metals showed higher concentrations in agricultural soils than in non-agricultural soils, and the site located in factory district contained metals much higher than the other sampling sites. These observations suggested that human activities, such as water irrigation, fertilizer and pesticide applications might have a major impact on the distribution of metals. Metal speciation analysis presented that Cu, Zn and Cd were dominated by the residual fraction, while Pb was dominated by the reducible fraction. Because of the low mobility of the metals in the investigated area, no remarkable difference could be observed between upstream and downstream separated by the factory site.
Show more [+] Less [-]Influence of urbanization and industrialization on metal enrichment of sediment cores from Shantou Bay, South China Full text
2013
Qiao, Yongmin | Yang, Yang | Zhao, Jiangang | Tao, Ran | Xu, Ronghua
Four sediment cores were collected to investigate geochemical sources and to assess enrichment and pollution of metals in sediments from Shantou Bay, an area experiencing rapid economic development on the Southeastern Coast of China. The results indicated that the concentrations of the majority of metals showed a decrease with depth, with overall maximum values in the top layers, and that different sampling locations in the Bay received slightly different types of inputs. Three major sources were identified by correlation analysis and principal component analysis: river inputs, metropolitan, and port facilities discharge. Calculation of a pollution load index revealed overall low values, but the enrichment factor values for Pb and Cd were typically high for all cores. The mean concentrations of Cu, Pb, Zn and to some extent Cd exceeded the Effects-Range-Low values in the majority of the cases, indicating that there were possible ecotoxicological risks to organisms in Shantou Bay.
Show more [+] Less [-]Contribution of a submerged membrane bioreactor in the treatment of synthetic effluent contaminated by Bisphenol-A: Mechanism of BPA removal and membrane fouling Full text
2013
Seyhi, Brahima | Drogui, Patrick | Buelna, Gerardo | Azaïs, Antonin | Heran, Marc
A submerged membrane bioreactor has been operated at the laboratory scale for the treatment of a synthetic effluent containing Bisphenol-A (BPA). COD, NH4–N, PO4–P and BPA were eliminated respectively, at 99%, 99%, 61% and 99%. The increase of volumetric loading rate from 0 to 21.6 g/m3/d did not affect the performance of the MBR system. However, the removal rate decreased rapidly when the BPA loading rate increased above 21.6 g/m3/d. The adsorption process of BPA on the biomass was very well described by Freundlich and Langmuir isotherms. Subsequently, biodegradation of BPA occurred and followed the first order kinetic reaction, with a constant rate of 1.13 ± 0.22 h−1. During treatment, membrane fouling was reversible in the first 84 h of filtration, and then became irreversible. The membrane fouling was mainly due to the accumulation of suspended solid and development of biofilm on the membrane surface.
Show more [+] Less [-]Bridging the gap between traffic generated health stressors in urban areas: Predicting xylene levels in EU cities Full text
2013
Vlachokostas, Ch | Michailidou, A.V. | Spyridi, D. | Moussiopoulos, Ν
Many citizens live, work, commute, or visit traffic intensive spaces and are exposed to high levels of chemical health stressors. However, urban conurbations worldwide present monitoring “shortage” – due to economical and/or practical constraints – for toxic stressors such as xylene isomers, which can pose human health risks. This “shortage” may be covered by the establishment of associations between rarely monitored substances such as xylenes and more frequently monitored (i.e. benzene) or usually monitored (i.e. CO). Regression analysis is used and strong statistical relationships are detected. The adopted models are applied to EU cities and comparison between measurements and predictions depicts their representativeness. The analysis provides transferability insights in an effort to bridge the gap between traffic-related stressors. Strong associations between substances of the air pollution mixture may be influential to interpret the complexity of the causal chain, especially if a synergetic exposure assessment in traffic intensive spaces is considered.
Show more [+] Less [-]A cohort study of intra-urban variations in volatile organic compounds and mortality, Toronto, Canada Full text
2013
Villeneuve, Paul J. | Jerrett, Michael | Su, Jason | Burnett, Richard T. | Chen, Hong | Brook, Jeffrey | Wheeler, Amanda J. | Cakmak, Sabit | Goldberg, Mark S.
This study investigated associations between long-term exposure to ambient volatile organic compounds (VOCs) and mortality. 58,760 Toronto residents (≥35 years of age) were selected from tax filings and followed from 1982 to 2004. Death information was extracted using record linkage to national mortality data. Land-use regression surfaces for benzene, n-hexane, and total hydrocarbons were generated from sampling campaigns in 2002 and 2004 and assigned to residential addresses in 1982. Cox regression was used to estimate relationships between each VOC and non-accidental, cardiovascular, and cancer mortality. Positive associations were observed for each VOC. In multi-pollutant models the benzene and total hydrocarbon signals were strongest for cancer. The hazard ratio for cancer that corresponded to an increase in the interquartile range of benzene (0.13 μg/m3) was 1.06 (95% CI = 1.02–1.11). Our findings suggest ambient concentrations of VOCs were associated with cancer mortality, and that these exposures did not confound our previously reported associations between NO2 and cardiovascular mortality.
Show more [+] Less [-]Effects of species-specific leaf characteristics and reduced water availability on fine particle capture efficiency of trees Full text
2013
Räsänen, Janne V. | Holopainen, Toini | Joutsensaari, Jorma | Ndam, Collins | Pasanen, Pertti | Rinnan, Åsmund | Kivimäenpää, Minna
Trees can improve air quality by capturing particles in their foliage. We determined the particle capture efficiencies of coniferous Pinus sylvestris and three broadleaved species: Betula pendula, Betula pubescens and Tilia vulgaris in a wind tunnel using NaCl particles. The importance of leaf surface structure, physiology and moderate soil drought on the particle capture efficiencies of the trees were determined. The results confirm earlier findings of more efficient particle capture by conifers compared to broadleaved plants. The particle capture efficiency of P. sylvestris (0.21%) was significantly higher than those of B. pubescens, T. vulgaris and B. pendula (0.083%, 0.047%, 0.043%, respectively). The small leaf size of P. sylvestris was the major characteristic that increased particle capture. Among the broadleaved species, low leaf wettability, low stomatal density and leaf hairiness increased particle capture. Moderate soil drought tended to increase particle capture efficiency of P. sylvestris.
Show more [+] Less [-]Discharge of landfill leachate to streambed sediments impacts the mineralization potential of phenoxy acid herbicides depending on the initial abundance of tfdA gene classes Full text
2013
Batıoğlu-Pazarbaşı, Meriç | Milosevic, Nemanja | Malaguerra, Flavio | Binning, Philip J. | Albrechtsen, Hans-Jørgen | Bjerg, Poul L. | Aamand, Jens
To understand the role of abundance of tfdA gene classes belonging to β- and γ-proteobacteria on phenoxy acid herbicide degradation, streambed sediments were sampled around three seepage meters (SMs) installed in a landfill-impacted groundwater–surface water interface. Highest herbicide mass discharge to SM3, and lower herbicide mass discharges to SM1 and SM2 were determined due to groundwater discharge rates and herbicide concentrations. SM1-sediment with the lowest abundance of tfdA gene classes had the slowest mineralization, whereas SM2- and SM3-sediments with more abundant tfdA genes had faster mineralization. The observed difference in mineralization rates between discharge zones was simulated by a Monod-based kinetic model, which confirmed the role of abundance of tfdA gene classes. This study suggests presence of specific degraders adapted to slow growth rate and high yield strategy due to long-term herbicide exposure; and thus groundwater–surface water interface could act as a natural biological filter and protect stream water quality.
Show more [+] Less [-]Mapping urban pipeline leaks: Methane leaks across Boston Full text
2013
Phillips, Nathan G. | Ackley, Robert | Crosson, Eric R. | Down, Adrian | Hutyra, Lucy R. | Brondfield, Max | Karr, Jonathan D. | Zhao, Kaiguang | Jackson, Robert B.
Natural gas is the largest source of anthropogenic emissions of methane (CH4) in the United States. To assess pipeline emissions across a major city, we mapped CH4 leaks across all 785 road miles in the city of Boston using a cavity-ring-down mobile CH4 analyzer. We identified 3356 CH4 leaks with concentrations exceeding up to 15 times the global background level. Separately, we measured δ13CH4 isotopic signatures from a subset of these leaks. The δ13CH4 signatures (mean = −42.8‰ ± 1.3‰ s.e.; n = 32) strongly indicate a fossil fuel source rather than a biogenic source for most of the leaks; natural gas sampled across the city had average δ13CH4 values of −36.8‰ (±0.7‰ s.e., n = 10), whereas CH4 collected from landfill sites, wetlands, and sewer systems had δ13CH4 signatures ∼20‰ lighter (μ = −57.8‰, ±1.6‰ s.e., n = 8). Repairing leaky natural gas distribution systems will reduce greenhouse gas emissions, increase consumer health and safety, and save money.
Show more [+] Less [-]A spatially-based modeling framework for assessing the risks of soil-associated metals to bats Full text
2013
Hernout, Béatrice V. | Somerwill, Kate E. | Arnold, Kathryn E. | McClean, Colin J. | Boxall, Alistair B.A.
Populations of some species of bats are declining in some regions of Europe. These declines are probably due to a range of pressures, including climate change, urbanization and exposure to toxins such as metals. This paper describes the development, paramaterisation and application of a spatially explicit modeling framework to predict the risks of soil-associated metals (lead, copper, zinc and cadmium) to bat health. Around 5.9% of areas where bats reside were predicted to have lead levels that pose a risk to bat health. For copper, this value was 2.8%, for cadmium it was 0.6% and for zinc 0.5%. Further work is therefore warranted to explore the impacts of soil-associated metals on bat populations in the UK.
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