Mutagenic activity of sludge samples generated in dyeing processing textile plants

The treatment of dyeing processing textile plants effluents uses activated sludge system and can generate tons of sludges that needs to be appropriately disposed. Genotoxic compounds can be present in those sludges, especially from the class of the organics, that are difficult to be chemically analyzed in complex mixtures. The objective of this work was the evaluation of the genotoxic activity of sludge samples using the Salmonella microsome test, a bioassay very suitable for the screening of those substances in environmental samples. We analyzed 6 different textile dyeing facilities, that dyes both synthetic fibers (polyester, nylon and others) and cotton. The organic extractable material using methanol as solvent, varied from 0,24 to 6,7 por cento. From the 15 samples analyzed, 12 showed positive responses mainly with TA98 in the presence of metabolic activation (S9). Considering the type of the mutagenic response obtained, compounds such as azo dyes and or aromatic amines and others could be responsible for this activity. A chemical characterization of the genotoxic compounds present in those samples is very important in order to allow an adequate classification and disposal of this type of waste

Isolamento de Salmonella no ambiente aquático: significado sanitário / Isolation of Salmonella from aquatic environment: sanitary significance

Para avaliar o significado sanitário de Salmonella em águas foram examinadas 894 amostras de águas de esgotos, salgadas e doces, sendo obtidos 5.430 isolamentos de Salmonella. Constatou-se que, nos esgotos os sorogrupos e sorotipos de Salmonella, com exceçäo de S. agona, apresentaram padräo de distribuiçäo similar ao obtido em coprocultura. Nos esgotos provenientes de hospitais predominou S. typhimurium var. 0:5- que também foi o mais frequentemente isolado de coproculturas. Foi observado que nos mananciais e praias mais poluidos, prevaleciam os sorogrupos e sorotipos mais comuns de esgotos, e o contrário ocorreu em amostras de locais menos poluídos. Näo foi obtida correlaçäo estatística entre NMP/100 mL salmonelas e NMP/100 mL de coliformes em esgoto, no entanto, quando se relacionou graficamente, níveis de coliformes e porcentagem de isolamento de salmonelas em águas doces e salgadas, obteve-se uma relaçäo praticamente linear