Integrative approach for monitoring the toxicity of effluents, surface water, and soil in the Cerrado biome

Abstract

Monitoring the quality of water resources is essential to determine environmental impacts and seek sustainable management solutions. In this work, we demonstrated the toxicity of effluents and surface water of an important river in Central Brazil, the Meia Ponte River, using not just physicochemical parameters but also ecotoxicological bioindicators, such as Aliivibrio fischeri, Allium cepa, Lactuca sativa, and Salmonella typhimurium. To complement this data, we analyzed soil toxicity and quality along the river bank using A. fischeri and microbial enzymes. The data was associated with the land use pattern to discuss the environmental impacts caused by the land use and cover in the Cerrado biome. Although most physicochemical parameters were within the values allowed by Brazilian legislation, the A. fischeri bioluminescence inhibition assay indicated sample toxicity mainly in the non-treated effluent and near the river mouth (both water and soil samples). The germination indexes for L. sativa and A. cepa were reduced in most samples. Mutagenicity was observed in a surface water sample of one collection point during the dry season. The current data suggest the toxic potential of the surface water and soil along the Meia Ponte River and the non-treated effluent. The effluent treatment decreased the toxic potential of the samples but did not always eliminate the toxicity. The toxicity of the Meia Ponte River was most observed in urban and agricultural areas. Finally, our work demonstrated the need to monitor the environmental health of the Meia Ponte River basin, also used for public water supply.