Assessment of human health risk of Chromium and Nitrate Pollution in groundwater and soil of the Matanza-Riachuelo River Basin, Argentina

Abstract

This study assesses hexavalent chromium [Cr(VI)] and nitrate (NO3−) in polluted groundwater and soil, and evaluates the impact on the health of the inhabitants of the Matanza-Riachuelo River basin, Argentina. Sixty groundwater samples and 18 soil samples were collected. Statistical analysis and Stiff diagrams were used for the hydrochemical characterization of the groundwater. A method developed by the United States Environmental Protection Agency for health risk assessment was applied to the Upper and the Puelche aquifers. The non-carcinogenic (NCR) and carcinogenic risks (CR) posed by Cr(VI) and NO3− in groundwater via ingestion and dermal contact were determined in children and adults. The effect of Cr on children through ingestion, dermal contact and inhalation as a result of exposure to soil was also established. The results indicated that the Cr(VI) and NO3− average values were 0.35 mg/L and 76 mg/L, respectively, in the Upper Aquifer, whereas the Cr(VI) average values were 1.41 mg/L and 38 mg/L for NO3− in the Puelche Aquifer. Children and adults exposed to groundwater via ingestion and dermal contact faced acceptable NCR of NO3−, but unacceptable NCR and CR of Cr(VI). Water ingestion was the main exposure route; HQing = 4.15 and 4.07 and CRing = 2.74E−03 and 2.36E−03 in children and adults, respectively, in the Upper Aquifer; HQing = 17 and 14.1 and CRing = 1.04E−02 and 9.81E−03 in children and adults, respectively, in the Puelche Aquifer. As regards the soil exposure pathways, NCR and CR of Cr(VI) are unacceptable, dermal contact being the main route (HQderm = 4.63; CRderm = 9.34E−04).