Metals in supply water of riverine communities affected by the largest environmental disaster in Brazil: the dam collapse on Doce River

Abstract

Considered the worst environmental disaster in brazilian history before another dam break at the same region, the collapse of Samarco dam directly affected the Doce river. Inhabitants living along the river who relied mainly on Doce river's water supply for agriculture and human consumption faced serious risk from the mining residue. This study aimed to investigate the disaster’s impact on small family farmers living in Minas Gerais and Espírito Santo state by water elemental quantification and evaluate the potential pathways of contamination by survey. In July 2016, 48 water points - including well, river and public distributed water - of 3 cities (Belo Oriente, Governador Valadares and Colatina) were sampled for determination of As, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Sn and Zn elements. 98% of the interviewed related using the Doce river water before the tragedy for diversified purposes, while only 36% used it after the disaster, mainly for irrigation. Fe and Mn presented concentrations above the brazilian legislation for drinking water and irrigation in all locations, but not in all samples. All the other elements concentrations were within safe limits. Colatina, the farthest city from the dam, presented the highest values, followed by Governador Valadares and Belo Oriente.