Chemical and ecotoxicological analyses of sediments and elutriates of contaminated rivers due to e-waste recycling activities using a diverse battery of bioassays.
ABSTRACT A multi-trophic, multi-exposure phase assessment approach was applied to characterize the toxicity of sediments collected from two rivers in Guiyu, China, an e-waste recycling centre. Elutriate toxicity tests (bacterium Vibrio fischeri and microalga Selenastrum capricornutum) and whole sediment toxicity test (crustacean Heterocypris incongruens) showed that most sediments exhibited acute toxicity, due to elevated heavy metals and PAHs levels, and low pH caused by uncontrolled acid discharge. The survival rates of crustaceans were negatively (p < 0.05) correlated with total PAHs in sediments (411-1755 mg kg(-1)); EC50s of V. fischeri on the elutriates were significantly correlated with elutriate pH (p < 0.01). Significant (p < 0.05) correlations between the induction of hepatic metallothionein in tilapia (Oreochromis mossambicus) and metal concentrations (Cu, Zn, Pb) in sediments were also observed, when fish were fed with diets containing sediment. The results showed that uncontrolled e-waste recycling activities may bring adverse effects to local aquatic ecosystem.
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ABSTRACT: This paper revises the response of freshwater ostracods to different environmental conditions and anthropogenic impacts, with a worldwide overview of the potential use of these microcrustaceans as bioindicators and several examples of applications in different scenarios. The development of either a single species or an ostracod assemblage is influenced by physical–chemical properties of waters (salinity, temperature, pH, dissolved oxygen), hydraulic conditions, bottom grain sizes or sedimentation rates. In addition to population and community changes, morphological and geochemical changes can also be detected in the ostracod carapace, which serves as a tracer of the water quality. All these features permit to delimit the spatial effects of urban sewages, mining effluents, agricultural wastes, watershed deforestation or road building. These data are the basis for the palaeoenvironmental reconstruction of cores, with an interesting application to archaeology. In addition, favourable results of recently developed bioassays, coupled with an important variability of local assemblages under changing conditions in both waters and sediments, suggest that these microcrustaceans may included between the most promising sentinels groups in freshwater areas. These microcrustaceans show high sensitivity to pesticides, herbicides, heavy metal pollution and oil inputs.International journal of Environmental Science and Technology 03/2013; · 1.84 Impact Factor
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ABSTRACT: Electronic waste (e-waste) has become a pressing global pollution issue. The situation in China is more severe, due to largely primitive recycling of e-waste generated domestically and imported from outside China. In China, the improper e-waste recycling operations have resulted in severe contamination of the ambient environments by toxic pollutants. All data suggest that the contaminant levels in various environmental media near e-waste recycling sites are substantially higher than those at reference sites. People living near e-waste recycling sites and adjacent regions are subject to increased health hazard. Long-range transport of e-wastederived pollutants can also subject residents in adjacent regions to unintended health risks. Given the special circumstances in China, implementation of improved e-waste recycling technologies and rigorous law enforcement should be the ultimate resolution for containing the spreading of e-waste-derived pollution.12/2012;
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ABSTRACT: We propose that a niche-based experimental approach at population level could be used to solve some uncertainties in traditional approaches in ecotoxicology. We tested this approach in the context of multiple stressors (i.e. chemical and physical) in a selection of six run-of-river reservoirs with different levels of sediment contamination and associated upstream and downstream river sites. A niche-based approach was tested using three functional traits (habitat, food preferences and body size) and discrepancy between the realized and theoretical niches. We first identified three groups of taxa and then recorded differences along the disturbance gradients, such as an increase in competition, a narrowing of spatial and trophic niche breadth (e.g. of Leuctra major and Gammarus pulex), a widening of spatial niche breadth (e.g. of Ephemerella ignita), a greater proportion of small individuals (e.g. of G. pulex) and a decreasing or an increasing (e.g. L. major) discrepancy between realized and theoretical niches.Environmental Pollution 11/2013; 185C:24-34. · 3.73 Impact Factor