title: Investigating the sources of the mutagenic activity found in a river using the Salmonella assay and different water extraction procedures.
abstract: In the routine São Paulo state (Brazil) surface water quality-monitoring program, which includes the Salmonella microsome mutagenicity assay as one of its parameters, a river where water is taken and treated for drinking water purposes has repeatedly shown mutagenic activity. A textile dyeing facility employing azo-type dyes was the only identifiable source of mutagenic compounds. We extracted the river and drinking water samples with XAD4 at neutral and acidic pH and with blue rayon, which selectively adsorbs polycyclic compounds. We tested the industrial effluent, raw, and treated water and sediment samples with YG1041 and YG1042 and compared the results with the TA98 and TA100 strains. The elevated mutagenicity detected with YG-strains suggested that nitroaromatics and/or aromatic amines were causing the mutagenicity detected in the samples analyzed. Positive responses for the blue rayon extracts indicated that mutagenic polycyclic compounds were present in the water samples analyzed. The mutagen or mixture of mutagens present in the effluent and water samples cause mainly frameshift mutations and are positive with and without metabolic activation. The Salmonella assay combined with different extraction procedures proved to be very useful in the identification of the origin of the pollution and in the identification of the classes of chemical compounds causing the mutagenic activity in the river analyzed.
authors.affiliation: CETESB--Cia. Tecnologia de Saneamento Ambiental, Av. Prof. Frederico Hermann Jr., 345, 05459-900, São Paulo, SP, Brazil. giselav@cetesb.sp.gov.br
authors.forename: Gisela de Aragão
authors.initials: Gde A
authors.lastname: Umbuzeiro
authors.forename: Deborah A
authors.initials: DA
authors.lastname: Roubicek
authors.forename: Célia Maria
authors.initials: CM
authors.lastname: Rech
authors.forename: Maria Inês Z
authors.initials: MI
authors.lastname: Sato
authors.forename: Larry D
authors.initials: LD
authors.lastname: Claxton
mesh_terms: D001938:Brazil; D004784:Environmental Monitoring; D016368:Frameshift Mutation / Q000235:genetics; D019015:Geologic Sediments / Q000032:analysis; D006841:Hydrocarbons, Aromatic / Q000032:analysis; D009152:Mutagenicity Tests; D009574:Nitro Compounds / Q000032:analysis; D045483:Rivers / Q000737:chemistry*; D012475:Salmonella / Q000235:genetics; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D006841:Hydrocarbons, Aromatic; D009574:Nitro Compounds; D014874:Water Pollutants, Chemical