Toxicity evaluation of Meiliang Bay, Lake Taihu, China - a drinking water source

In this study, potential toxicity in organic pollutants in Meiliang Bay, Lake Taihu, a drinking water source, was investigated using the comet assay and zebrafish embryo test, and two control sites in Lake Changdang and the Changjiang (Yangtze) River were established. For the genotoxicity assay, results showed that organic extracts from water samples induce DNA damage on human lymphocytes and mouse testicular cells. A statistically significant difference (p < 0.01) was observed versus the solvent control, as shown by multiple comparisons at a dose of 100 ml tube(-1). The degree of DNA damage caused by Meiliang Bay water was most serious (human lymphocytes cells-184 arbitrary units (AU); 234 AU on mouse testicular cells). Organic extracts also affected zebrafish embryo development. Embryo coagulation, axis abnormality, slow absorbability of vitellicle, and multi-edema related to teratogenesis at 96 hpf were observed. In the high dose group, there was obvious edema in the hearts and vitellicles for most dysplastic embryos. Toxic potential in organic pollutants in drinking water sources from the Yangtze River and Lake Changdang were less serious than Meiliang Bay. Therefore, the drinking water source in Meiliang Bay was unsafe compared to the Changjiang River and Lake Changdang, and it is exigent that Meiliang Bay water quality should be ameliorated further.