This paper presents the genotoxicity experiments with the ground water collected from an area under the influence of textile dyeing and bleaching industries in Tirupur, Tamilnadu, India. The alkaline single cell gel electrophoresis (SCGE) assay was performed in vitro with human peripheral blood lymphocytes. The cells were exposed to two doses of non-volatile organic agents extracted from ground water samples. Ground water samples were collected from 12 locations distributed in and around Tirupur and extracts were taken at different pHs (without pH adjustment and acidic pH 2.0). The persistence of the DNA damage after exposure to the organic extracts was also studied. All the samples were found to contain substances capable of inducing DNA damage in human lymphocytes. Extracts from acidified waters (pH=2.0) were found to induce more DNA damage than extracts from without pH adjustment (natural pH). The DNA damage was not fully repaired after incubation for 2h at 37°C. The chemical characterization of the sub-fractions revealed the existence of aromatic amines in the extracts, which may be responsible for the DNA damaging activity of the water samples. The results of this investigation demonstrate the application of the comet assay in environmental monitoring studies.

This report presents the results of a genotoxicity study to evaluate the DNA damage caused by four sulfur dyes used in the textile and tannery industries. Alkaline single‐cell gel electrophoresis assay (SCGE) was performed on erythrocytes from Rana hexadactyla tadpoles following whole‐body exposure to increasing concentrations of the dyes. The dyes, along with their active ingredients, were Sandopel Basic Black BHLN, Negrosine, Dermapel Black FNI, and Turquoise Blue. The dye‐treated tadpoles showed significant DNA damage, measured as mean DNA length:width ratio, when compared with unexposed control animals. Among the four tested dyes Sandopel Basic Black BHLN appears to be highly genotoxic, Dermapel Black FNI was least genotoxic, and Negrosine and Turquoise Blue were moderately toxic to R. hexadactyla tadpoles. The tadpoles showed a significant reduction in DNA damage when placed in dechlorinated tap water after exposure for a 24‐hr period to the dye solutions. Environ. Mol. Mutagen. 38:316–322, 2001. © 2001 Wiley‐Liss, Inc.