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AZO DYES ARE MAJOR CONTRIBUTORS TO THE MUTAGENIC ACTIVITY DETECTED IN THE CRISTAIS RIVER WATERS
Citation:
Umbuzeiro, G. A., H. Freeman, S H. Warren, D. P. de Oliveira, M. Sakagami, Y. Terao, T. Watanabe, AND L D. Claxton. AZO DYES ARE MAJOR CONTRIBUTORS TO THE MUTAGENIC ACTIVITY DETECTED IN THE CRISTAIS RIVER WATERS. Presented at Environmental Mutagen Society, Pittsburgh, PA, October 2-6, 2004.
Description:
To determine if compounds from 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, which tested positive in the Salmonella assay, corresponded to a commercial product used by the industry. 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, the C.I. Disperse Violet 93 and the orange, the C.I. Disperse Orange 37. The dyes showed mutagenic responses of 6,300, 4,600, and 280 revertants/?g for YG1041 with S9. 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 55% of the mutagenic activity of the DWTP sludge. We showed that the azo dye processing plant treatment was inefficient 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 established especially where the resultant water is taken for human consumption.