Rainwater toxicity and contamination study from São Paulo Metropolitan Region, Brazil

Abstract

Wet deposition is an important process that removes pollutants from the atmosphere and transfers them to waters and soil. The goal of this study was to assess the biological effects of the atmospheric contamination of rainwater in the metropolitan area of São Paulo (MASP) using Daphnia similis, Ceriodaphnia dubia, and Vibrio fischeri. Experimental assays were carried out according to standard toxicity methodology. Twenty-three rainwater samples were collected from October 2007 to December 2008, at the Nuclear Research Institute (IPEN), in MASP. Major ions were determined by ionic chromatography, which showed NH 4 + and NO 3 − as prevalent ions. Ecotoxicological results confirmed toxic potential of rainwater, as all samples were toxic to D. similis and C. dubia. The V. fischeri luminescence reduction confirmed those negative effects of rainwater and percentage inhibition of relative luminescence ranged from 0.2 to 0.9 for 16 samples. Worse conditions were observed during the rainy season, suggesting convective rains are more effective in transferring contaminants and toxicity from atmosphere to surface.

A review on physicochemical and microbiological contamination of roof-harvested rainwater in urban areas

“…The presence of nitrate originated from anthropogenic activity in the rainfall is recurrent in urban areas worldwide. In the Metropolitan Region of São Paulo (Brazil) which is the biggest urban area of South America with 20 million people, analysis through ionic chromatography showed NH 4 + and NO 3 À as the prevalent ions (Martins et al, 2014). Most of the nitrate and other nitrogen oxides as well as ammonium present in the stormwater runoff may end contributing to the pollution of groundwater in urban areas (Umezawa et al, 2008Umezawa et al, 2009).…”