Comparative temporal ecotoxicological study in a river basin influenced by petrochemical industries.

An approach was developed to evaluate ecotoxicological effects in river basins impacted by anthropic industrial discharges. Genotoxicity was the first level of evaluation of the river water, but when cytotoxicity was associated with genotoxic effects, our research group added chronic assays allowing the assessment of the ontogenic cycle in environmental diagnosis. The genotoxicity of river water sampled during two periods was compared using the microscreen phage-induction and Salmonella/microsome assays.

River water genotoxicity evaluation using micronucleus assay in fish erythrocytes.

The quality of Caí river water (Rio Grande do Sul State) in an area under the influence of a petrochemical complex was studied using the micronucleus assay in erythrocytes from peripheral blood of the fathead minnow Pimephales promelas. This cytogenetic in vivo assay was performed to evaluate the effects of petrochemical effluents on the stream. Organisms were exposed to samples collected at four sites, during an 11-month period.

Genotoxicity and toxicity assessment in urban hydrographic basins.

The genotoxicity and cytotoxicity of water in small urban basins was evaluated by the Salmonella/microsome assay and micronucleus test in V79 cells. The results showed that the cytotoxic effect was the most significant response in areas with medium to heavy urban occupation for both assays evaluated. Water samples from these areas include different concentrations of chloroform, bromodichloromethane, toluene, ethylbenzene, m,p-xylene and 1,4-dichlorobenzene.