Total arsenic and inorganic arsenic speciation in groundwater intended for human consumption in Uruguay: Correlation with fluoride, iron, manganese and sulfate

Abstract

Medical Geology is a growing field in Uruguay and the groundwater quality has been the focus of multiple studies, being As levels one of its main concerns. The aim of this study was the application of analytical methodologies for the assessment of total arsenic and inorganic arsenic species, fluoride, iron, manganese and sulfate in groundwater samples from private wells, used for human consumption, and to evaluate the possible correlations among these parameters. The accuracy of the methods was ensured by using certified reference materials. A total of 48 groundwater samples from Uruguay were analyzed. The concentration ranges found were: tAs (1.72–120.48) μg L−1, F− (0.024–1.528) mg L−1, Fe (0.62–211.38) μg L−1 and Mn (0.11–8.705) μg L−1. Almost half of the samples presented tAs concentration levels above those recommended by WHO for drinking water (10 μg L−1), with the corresponding risks for human health. Results showed higher As(V) levels in the samples, which is in agreement with the oxidant conditions of the wells. Pearson correlations were performed, resulting in strong positive correlations for As/F−, As(V)/F− and As(V)/SO42−. As levels in groundwater and its relationship with other inorganic parameters, should be deeply studied to prevent long-term health effects.