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THE CONTRIBUTION OF AZO DYES TO THE MUTAGENIC ACTIVITY OF THE CRISTAIS RIVER
Citation:
Umbuzeiro, G. A., H. S. Freeman, S H. Warren, D. Palma de Olivera, M. Sakagami, Terao Y, T. Watanabe, AND L D. Claxton. THE CONTRIBUTION OF AZO DYES TO THE MUTAGENIC ACTIVITY OF THE CRISTAIS RIVER . CHEMOSPHERE 60(1):55-64, (2005).
Description:
To verify if compounds within the discharge of a dye processing plant were contributing to the mutagenicity repeatedly found in the Cristais River, Sao Paulo, Brazil, we chemically characterized the treated industrial effluent, raw and treated water, and the sludge produced by a Drinking Water Treatment Plant (DWTP) located ~6 km from the industrial discharge. Thin layer chromatographic analysis indicated the presence of three prevalent dyes in all samples, except for the drinking water. This dye combination corresponded to a commercial product used by the industry, and the dye tested positive in the Salmonella assay. The structures of the dye components were analyzed using proton magnetic resonance and mass spectrometric (MS) methods, and the dyes were tested for mutagenicity. The blue component was identified as the C.I. Disperse Blue 373, the violet, C.I. Disperse Violet 93, and the orange, C.I. Disperse Orange 37. The dyes showed mutagenic responses of 6,300, 4,600, and 280 revertants/?g for YG1041 with S9 respectively. Aromatic amines were also detected in the samples using a GC/MS technique. A bioassay-directed fractionation/chemical analysis showed that the C.I. Disperse Blue 373 contributed to 55% of the mutagenic activity of the DWTP sludge. We concluded that the azo dye processing plant treatment was not efficient in the removal of dyes and their aromatic amine precursors. Since these compounds contribute to the mutagenic activity found in the associated environmental samples, the human and ecological risks associated with the release of dye processing plant effluents should be more fully characterized especially where the resultant water is taken for human consumption.