as a suitable model to evaluate the toxicity of water from Rolante River, southern Brazil.

Urbanization and agricultural activities increased environmental contaminants. Integrated analysis of water parameters and bioassays represents an essential approach to evaluating aquatic resource quality. This study aimed to assess water quality by microbiological and physicochemical parameters as well as the toxicological effects of water samples on the Ames test and model. Samples were collected during (collection 1) and after (collection 2) pesticide application in the upper (S1), middle (S2), and lower (S3) sections of the Rolante River, southern Brazil. Metals were determined by GFAAS and pesticides by UPLC-MS/MS. Bioassays using the Ames test and the nematode Levels of microbiological parameters, as well as Mn and Cu were higher than the maximum allowed limits established by legislation in collection 2 compared to collection 1. The presence of pesticide was observed in both collections; higher levels were found in collection 1. No mutagenic effect was detected. Significant inhibition of body length of was found in collection 1 at S2 ( < 0.001) and S3 ( < 0.001) and in collection 2 at S2 ( = 0.004). Comparing the same sampling site between collections, a significant difference was found between the site of collection (F(3,6)=8.75,  = 0.01) and the time of collection (F(1,2)=28.61,  = 0.03), for the S2 and S3 samples. model was useful for assessing surface water quality/toxicity. Results suggest that an integrated analysis for the surface water status could be beneficial for future approaches.