Abstract:
The Gravataí River basin, one of the main water sources of the metropolitan region of Porto Alegre, is among the
ten most polluted rivers in Brazil. Water quality is monitored only through physico-chemical and microbiological
parameters in Brazil, and in this context, considering the importance of the use of biomarkers in complementing
the analysis of water, the present study aimed to evaluate the environmental quality of the main affluent of the
Gravataí River, Demetrio stream, through physico-chemical, microbiological, and cytogenotoxic criteria, at the
stream source (P1), whereas samples P2 and P3 were obtained from the upstream near the area with the highest
urban density and the downstream near the meeting point with the Gravataí River, respectively. The results for
copper concentration and color classified the Demetrio stream as Class 4 in general, that is, the water is suitable
only for navigation and to landscape harmony. The main genotoxic alterations (micronuclei and nuclear buds)
were observed in P2, in which were obtained the highest levels of copper, in addition to iron and manganese.
Anthropic interventions were observed in P1 and P2; however, due to its low metal concentration, P3, near the
Gravataí River, manifested an improvement in environmental quality.
