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Metabarcoding of benthic eukaryote communities predicts the ecological condition of estuaries
2015
Chariton, Anthony A. | Stephenson, Sarah | Morgan, Matthew J. | Steven, Andrew D.L. | Colloff, Matthew J. | Court, Leon N. | Hardy, Christopher M.
DNA-derived measurements of biological composition have the potential to produce data covering all of life, and provide a tantalizing proposition for researchers and managers. We used metabarcoding to compare benthic eukaryote composition from five estuaries of varying condition. In contrast to traditional studies, we found biotic richness was greatest in the most disturbed estuary, with this being due to the large volume of extraneous material (i.e. run-off from aquaculture, agriculture and other catchment activities) being deposited in the system. In addition, we found strong correlations between composition and a number of environmental variables, including nutrients, pH and turbidity. A wide range of taxa responded to these environmental gradients, providing new insights into their sensitivities to natural and anthropogenic stressors. Metabarcoding has the capacity to bolster current monitoring techniques, enabling the decisions regarding ecological condition to be based on a more holistic view of biodiversity.
Mostrar más [+] Menos [-]Joint effects of pesticides and ultraviolet-B radiation on amphibian larvae
2015
Yu, Shuangying | Wages, Mike | Willming, Morgan | Cobb, George P. | Maul, Jonathan D.
A combination of multiple stressors may be linked to global amphibian declines. Of these, pesticides and UVB radiation co-exposures were examined on the African clawed frog (Xenopus laevis) to provide information that may be useful for amphibian conservation. The independent action model and inferential statistics were used to examine interactions between pesticides (malathion, endosulfan, α-cypermethrin, or chlorothalonil) and environmentally relevant UVB exposures. UVB radiation alone caused 35–68% mortality and nearly 100% of malformations. Pesticides and UVB had additive effects on larval mortality; however, several non-additive effects (antagonistic and synergistic interactions) were observed for total body length. Insecticides mainly affected axial development, whereas UVB radiation caused high incidence of edema, gut malformations, and abnormal tail tips. These results suggest that sublethal developmental endpoints were more sensitive for detecting joint effects. This work has implications for amphibian risk assessments for ecosystems where pesticides and high UVB radiation may co-occur.
Mostrar más [+] Menos [-]Impact of 70 years urban growth associated with heavy metal pollution
2015
Rodríguez Martín, J.A. | De Arana, C. | Ramos-Miras, J.J. | Gil, C. | Boluda, R.
Historical trends in trace element deposition were analyzed using herbaria specimens. We determined Al, Fe, Mg, Mn, Ca, Na, P, K, S, As, Cd, Cr, Cu, Ni, Pb and Zn contents in leaves of eight specimens collected in 1941. To assess changes, we collected the same plants from a botanical garden in 2012. The concentrations of major elements showed large species variability. However, temporal trends were predominately detected for heavy metals. The Cd, Ni and Cr contents in the 2012 leaves were 10, 13 and 16 times higher, respectively, than in 1941. Urban activities have substantially raised the levels of these metals in urban atmospheres due to changes in human activities over 70 years of urban growth. Nevertheless, Pb has decreased (−126%) in recent decades thanks to controlled lead fuel combustion. In short, metal deposition trend to increase Cr, Ni and Cd levels.
Mostrar más [+] Menos [-]Occurrence and spatial distribution of organophosphate ester flame retardants and plasticizers in 40 rivers draining into the Bohai Sea, north China
2015
Wang, Runmei | Tang, Jianhui | Xie, Zhiyong | Mi, Wenying | Chen, Yingjun | Wolschke, Hendrik | Tian, Chongguo | Pan, Xiaohui | Luo, Yongming | Ebinghaus, Ralf
Organophosphate esters (OPEs) are alternatives to polybrominated diphenyl ethers, often used as flame-retardants and plasticizers. There are few reports of OPEs in river water. This study focused on the occurrence and spatial distribution of 11 OPE congeners and one synthetic intermediate triphenylphosphine oxide (TPPO) in 40 major rivers entering into the Bohai Sea. Total OPEs ranged from 9.6 to 1549 ng L−1, with an average of 300 ng L−1. Tris(1-chloro-2-propyl) phosphate (TCPP) (4.6–921 ng L−1, mean: 186 ng L−1) and tris(2-choroethyl) phosphate (TCEP) (1.3–268 ng L−1, mean: 80.2 ng L−1) were the most abundant OPEs and their distribution patterns are similar, indicating the same source (r = 0.61, P < 0.05) and the influence of large production and consumption of chlorinated OPEs in the region. Priority should be given to TCPP, PCEP and TPPO due to their high concentrations in the rivers and potential threat to aquatic organisms.
Mostrar más [+] Menos [-]Joint toxicity of sediment-associated permethrin and cadmium to Chironomus dilutus: The role of bioavailability and enzymatic activities
2015
Chen, Xin | Li, Huizhen | Yau, Ching
Pyrethroid insecticides and metals commonly co-occurred in sediment and caused toxicity to benthic organisms jointly. To improve accuracy in assessing risk of the sediments contaminated by insecticides and metals, it is of great importance to understand interaction between the contaminants and reasons for the interaction. In the current study, permethrin and cadmium were chosen as representative contaminants to study joint toxicity of pyrethroids and metals to a benthic invertebrate Chironomus dilutus. A median effect/combination index-isobologram was applied to evaluate the interaction between sediment-bound permethrin and cadmium at three dose ratios. Antagonistic interaction was observed in the midges for all treatments. Comparatively, cadmium-dominated group (the ratio of toxicity contribution from permethrin and cadmium was 1:3) showed stronger antagonism than equitoxicity (1:1) and permethrin-dominated groups (3:1). The reasons for the observed antagonism were elucidated from two aspects, including bioavailability and enzymatic activity. The bioavailability of permethrin, expressed as the freely dissolved concentrations in sediment porewater and measured by solid phase microextraction, was not altered by the addition of cadmium, suggesting the change in permethrin bioavailability was not the reason for the antagonism. On the other hand, the activities of metabolic enzymes, glutathione S-transferase and carboxylesterase in the midges which were exposed to mixtures of permethrin and cadmium were significantly higher than those in the midges exposed to permethrin solely. Cadmium considerably enhanced the detoxifying processes of permethrin in the midges, which largely explained the observed antagonistic interaction between permethrin and cadmium.
Mostrar más [+] Menos [-]Tracking changing X-ray contrast media application to an urban-influenced karst aquifer in the Wadi Shueib, Jordan
2015
Zemann, Moritz | Wolf, Leif | Grimmeisen, Felix | Tiehm, Andreas | Klinger, J. (Jochen) | Hötzl, Heinz | Goldscheider, Nico
Sewage input into a karst aquifer via leaking sewers and cesspits was investigated over five years in an urbanized catchment. Of 66 samples, analyzed for 25 pharmaceuticals, 91% indicated detectable concentrations. The former standard iodinated X-ray contrast medium (ICM) diatrizoic acid was detected most frequently. Remarkably, it was found more frequently in groundwater (79%, median: 54 ng/l) than in wastewater (21%, 120 ng/l), which is supposed to be the only source in this area. In contrast, iopamidol, a possible substitute, spread over the aquifer during the investigation period whereas concentrations were two orders of magnitude higher in wastewater than in groundwater. Knowledge about changing application of pharmaceuticals thus is essential to assess urban impacts on aquifers, especially when applying mass balances. Since correlated concentrations provide conclusive evidence that, for this catchment, nitrate in groundwater rather comes from urban than from rural sources, ICM are considered useful tracers.
Mostrar más [+] Menos [-]Concentrations and origins of nitro-polycyclic aromatic hydrocarbons and oxy-polycyclic aromatic hydrocarbons in ambient air in urban and rural areas in northern China
2015
Li, Wei | Wang, Chen | Shen, Huizhong | Su, Shu | Shen, Guofeng | Huang, Ye | Zhang, Yanyan | Chen, Yuanchen | Chen, Han | Lin, Nan | Zhuo, Shaojie | Zhong, Qirui | Wang, Xilong | Liu, Junfeng | Li, Bengang | Liu, Wenxin | Tao, Shu
Twelve nitro-PAHs (nPAHs) and four oxy-PAHs (oPAHs) were measured in air samples for 12 months at 18 sites in urban settings, rural villages, or rural fields in northern China. The nPAH concentrations were higher in urban areas (1.3 ± 1.3 ng/m3), and nPAH/parent PAH ratios were higher (suggesting important contributions from motor vehicles and secondary formation) in urban sites than in rural villages. oPAHs are primarily emitted from solid fuel combustion and motor vehicles, and similar oPAH concentrations were found in urban areas (23 ± 20 ng/m3) and rural villages (29 ± 24 ng/m3). The high numbers of motor vehicles in Beijing and intensive industrial activity in Taiyuan and Dezhou caused higher nPAH concentrations. No spatial trend in oPAH concentrations was found in the rural villages, because similar oPAH mixtures are emitted from solild fuel combustion. The nPAH and oPAH concentrations were higher in the winter, and correlated with residential energy consumption and precipitation.
Mostrar más [+] Menos [-]Effects of oil pipeline explosion on ambient particulate matter and their associated polycyclic aromatic hydrocarbons
2015
Zhao, Yue | Cao, Lixin | Zhou, Qing | Que, Qiming | Hong, Bo
Effects of the oil pipeline explosion on PM2.5-associated polycyclic aromatic hydrocarbons (PAHs) and their substituted (alkylated, nitrated, oxygenated, hydroxyl and chlorinated) derivatives are assessed near the accident scene of Qingdao, China. Compared with those in TSP-PM2.5, gaseous phase, burn residue and unburned crude oil, eighty-nine PAHs in PM2.5 are identified and quantified to investigate the composition, temporal and spatial distribution, and sources. The concentrations of PM2.5-associated parent PAHs increase approximately seven times from the non-explosion samples to the explosion samples (mean ± standard deviation: 112 ± 2 vs 764 ± 15 ng/m3), while some substituted products (nitro- and oxy-) increase by two orders of magnitude (3117 ± 156 pg/m3 vs 740 ± 37 ng/m3). The toxicity evaluation indicates the BaP equivalent concentrations (based on the US EPA's toxicity factors) in PM2.5 are much higher than those in the other phases, especially for a long duration after the tragic accident.
Mostrar más [+] Menos [-]Spatiotemporal distribution of carbonyl compounds in China
2015
Ho, K.F. | Ho, Steven Sai Hang | Huang, R.-J. | Dai, W.T. | Cao, J.J. | Tian, Linwei | Deng, W.J.
A sampling campaign was carried out at nine Chinese cities in 2010/2011. Fifteen monocarbonyls (C# = 1–9) were quantified. Temperature is the rate-determining factor of the summertime carbonyl levels. The carbonyl emissions in winter are mainly driven by the primary anthropogenic sources like automobile. A molar ratio of propionaldehyde to nonaldehyde is a barometer of the impact of atmospheric vegetation emission which suggesting that strong vegetation emissions exist in summer and high propionaldehyde abundance is caused by fossil fuel combustion in winter. Potential health risk assessment of formaldehyde and acetaldehyde was conducted and the highest cumulative risks were observed at Chengdu in summer and Wuhan in winter. Because of the strong photochemical reaction and large amount of anthropogenic emissions, high concentrations of carbonyl compounds were observed in Chengdu. The use of ethanol-blended gasoline in Wuhan is the key reason of acetaldehyde emission and action should be taken to avoid potential health risks.
Mostrar más [+] Menos [-]International scale implementation of the CNOSSOS-EU road traffic noise prediction model for epidemiological studies
2015
Morley, D.W. | de Hoogh, K. | Fecht, D. | Fabbri, F. | Bell, M. | Goodman, P.S. | Elliott, P. | Hodgson, S. | Hansell, A.L. | Gulliver, J.
The EU-FP7-funded BioSHaRE project is using individual-level data pooled from several national cohort studies in Europe to investigate the relationship of road traffic noise and health. The detailed input data (land cover and traffic characteristics) required for noise exposure modelling are not always available over whole countries while data that are comparable in spatial resolution between different countries is needed for harmonised exposure assessment. Here, we assess the feasibility using the CNOSSOS-EU road traffic noise prediction model with coarser input data in terms of model performance. Starting with a model using the highest resolution datasets, we progressively introduced lower resolution data over five further model runs and compared noise level estimates to measurements. We conclude that a low resolution noise model should provide adequate performance for exposure ranking (Spearman's rank = 0.75; p < 0.001), but with relatively large errors in predicted noise levels (RMSE = 4.46 dB(A)).
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