title: The contribution of azo dyes to the mutagenic activity of the Cristais River.
abstract: To verify whether dyes emitted 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 following mutagenic samples: the treated industrial effluent, raw and treated water, and the sludge produced by a Drinking Water Treatment Plant (DWTP) located approximately 6 km from the industrial discharge. Considering that 20% of the dyes used for coloring activities might be lost to wastewaters and knowing that several dyes have mutagenic activity, we decided to analyze the samples for the presence of dyes. Thin layer chromatographic analysis indicated the presence of three prevalent dyes in all samples, except for the drinking water. This combination of dyes corresponded to a commercial product used by the industry, and it tested positive in the Salmonella assay. The structures of the dye components were determined 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 as C.I. Disperse Violet 93, and the orange as C.I. Disperse Orange 37. The dyes showed mutagenic responses of 6300, 4600, and 280 revertants/microg for YG1041 with S9 respectively. 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 these dyes contributed to the mutagenic activity found in the Cristais River environmental samples analyzed and are indirectly affecting the quality of the related drinking water. Therefore, we believe that this type of discharge should be more thoroughly characterized chemically and toxicologically. Additionally, human and ecological risks associated with the release of dye processing plant effluents should be more fully investigated, especially where the resultant water is taken for human consumption.
authors.affiliation: CETESB-Cia de Tecnologia de Saneamento Ambiental, Av. Prof. Frederico Hermann Jr., 345, 05459-900, São Paulo, SP, Brazil. giselav@cetesb.sp.gov.br
authors.forename: Gisela
authors.initials: G
authors.lastname: de Aragão Umbuzeiro
authors.forename: Harold S
authors.initials: HS
authors.lastname: Freeman
authors.forename: Sarah H
authors.initials: SH
authors.lastname: Warren
authors.forename: Danielle Palma
authors.initials: DP
authors.lastname: de Oliveira
authors.forename: Yoshiyasu
authors.initials: Y
authors.lastname: Terao
authors.forename: Tetsushi
authors.initials: T
authors.lastname: Watanabe
authors.forename: Larry D
authors.initials: LD
authors.lastname: Claxton
mesh_terms: D000818:Animals; D001391:Azo Compounds / Q000737:chemistry / Q000633:toxicity*; D001681:Biological Assay; D001938:Brazil; D002855:Chromatography, Thin Layer; D004396:Coloring Agents / Q000737:chemistry / Q000633:toxicity*; D005618:Fresh Water / Q000032:analysis; D066298:In Vitro Techniques; D007220:Industrial Waste / Q000009:adverse effects / Q000032:analysis; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D008862:Microsomes, Liver / Q000378:metabolism; D009152:Mutagenicity Tests; D009153:Mutagens / Q000737:chemistry / Q000633:toxicity*; D051381:Rats; D012475:Salmonella / Q000187:drug effects; D013783:Textile Industry; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000633:toxicity*; D014881:Water Supply / Q000032:analysis
chemical_list: D001391:Azo Compounds; D004396:Coloring Agents; D007220:Industrial Waste; D009153:Mutagens; D014874:Water Pollutants, Chemical