Assessing of genotoxicity of 16 centralized source-waters in China by means of the SOS/umu assay and the micronucleus test: Initial identification of the potential genotoxicants by use of a GC/MS method and the QSAR Toolbox 3.0

Abstract

Only few studies were conducted to assess genotoxicity of centralized source waters in China and almost none of them dealt with the causal relationship between the genotoxic effect and genotoxicants. In this work, 16 centralized source waters in China were sampled from five river systems and genotoxicity of their organic extracts was assessed by use of the SOS/umu test for DNA-damaging effect and the miniaturized flow cytometry-based micronucleus (MN) test for chromosome-damaging effect. In addition, initial identification of potential genotoxicants for the six samples from the Yangtze River was done with a GC/MS method and the QSAR toolbox 3.0. The results demonstrate that eight samples showed both indirect and direct DNA-damaging effects, another four samples showed only indirect DNA-damaging effects, while chromosome-damaging effects were found for 14 out of the 16 samples, in which aneugenic and clastogenic modes of action were found for 4 and 10 samples, respectively. Both direct/indirect DNAdamaging effects and chromosome-damaging effects were induced by the six Yangtze River samples, and the existing different types of genotoxicant confirmed the results. Furthermore, o-phenylphenol was initially identified as the major cause for the DNA-damaging effects while PAHs, pesticides, phenol and anthraquinone were identified as ubiquitous chromosome-damaging agents among these samples. In conclusion, a combination of the SOS/umu test and the miniaturized flow cytometry-based MN test to detect both DNA-damaging and chromosome-damaging effects could be used as a comprehensive genotoxicity assessment tool for the evaluation and classification of genotoxicity of complex mixtures, and potential genotoxicants can be initially identified with additional information from chemical analysis and the QSAR toolbox.

Mutagenicity of drinking water sampled from the Yangtze River and Hanshui River (Wuhan section) and correlations with water quality parameters

“…Indeed, many researchers have reported that substances with genotoxic, and mutagenic activities are detectable in most source waters in China5101112. The Yangtze River, the largest river in Asia, with a length of 6,397 km, flows through Wuhan City, the capital of Hubei Province, with a population of 10,000,000, and is the main water supply for the city.…”

Assessment of municipal wastewater genotoxicity using the Ames fluctuation test the SOS Chromotest and the mussel micronucleus test a comparison

“…However, as bacterial genotoxicity assays detect DNA aberration and the MN test detects chromosomal damage, the genotoxic risk screened by the bacterial tests does not necessarily overlap with the MN test results [24]. The same authors therefore suggest the application of both the MN test and a bacterial test.…”

Development of a data-processing method based on Bayesian k-means clustering to discriminate aneugens and clastogens in a high-content micronucleus assay

“…All test chemicals were purchased from reliable sources and were of the highest commercially available grade. The reagents and chemical solution were prepared based on published methods 27 with slight modifications.…”