Blue rayon-anchored technique/Salmonella microsome microsuspension assay as a tool to monitor for genotoxic polycyclic compounds in Santos estuary.

The most important harbor of Brazil is located in Santos Estuary. In the 1970s, this area was one of the major examples of coastal degradation and although the quality of the environment has improved, the sediment is still contaminated with polycyclic aromatic hydrocarbons (PAHs) and mutagenic activity. Because of sediment dredging and consequently contaminants resuspension, it is useful to have reliable methods to monitor the water quality. Considering that blue rayon (BR) has been successfully used in evaluation of mutagenicity and PAHs content the objective of this work was to verify the applicability and adapt the methodology to monitor the water for mutagenic activity using the BR associated with the Salmonella assay. Analysis of three sites with different levels of contamination was performed using a modification of the BR hanging method denominated in this work BR anchored technique. The microsuspension protocol of the Salmonella/microsome assay was employed with the strain YG1041. The water from the site 1 the most contaminated and under influence of the steel mill discharge presented the highest potency reaching 36,000 revertants/g of BR with S9. Sites 2 and 3 showed less mutagenicity than site 1 with values approximately 1000 revertants/g of BR. We conclude that the BR anchored technique associated with Salmonella assay using YG1041 is a reliable alternative to monitor estuarine waters, especially in regions where sediment resuspension or acute pollution episodes can occur.

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

Comparison of the mutagenic activity of XAD4 and blue rayon extracts of surface water and related drinking water samples.

The combination of mutagenicity tests and selective extraction methodologies can be useful to indicate the possible classes of genotoxic organic contaminants in water samples. Treated and source water samples from two sites were analyzed: a river under the influence of an azo dye-processing plant discharge and a reservoir not directly impacted with industrial discharges, but contaminated with untreated domestic sewage. Organic extraction was performed in columns packed with XAD4 resin, that adsorbs a broad class of mutagenic compounds like polycyclic aromatic hydrocarbons (PAHs), arylamines, nitrocompounds, quinolines, antraquinones, etc., including the halogenated disinfection by-products; and with blue rayon that selectively adsorbs polycyclic planar structures. The organic extracts were tested for mutagenicity with the Salmonella assay using TA98 and TA100 strains and the potencies were compared. A protocol for cleaning the blue rayon fibers was developed and the efficiency of the reused fibers was analyzed with spiked samples. For the river water samples under the influence of the azo-type dye-processing plant, the mutagenicity was much higher for both blue rayon and XAD4 extracts when compared to the water from the reservoir not directly impacted with industrial discharges. For the drinking water samples, although both sites showed mutagenic responses with XAD4, only samples from the site under the influence of the industrial discharge showed mutagenic activity with the blue rayon extraction, suggesting the presence of polycyclic compounds in those samples. As expected, negative results were found with the blue rayon extracts of the drinking water collected from the reservoir not contaminated with industrial discharges. In this case, it appears that using the blue rayon to extract drinking water samples and comparing the results with the XAD resin extracts we were able to distinguish the mutagenicity caused by industrial contaminants from the halogenated disinfection by-products generated during water treatment.

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