Natural contamination by arsenic in the groundwater of the rural community "La Fuente", to suggest and promote the use of alternative sources of safe water, municipality La Paz Centro, León, Nicaragua

Abstract

Previous studies have revealed that in Nicaragua the presence of arsenic is of geogenic origin, so it is common to find it in both, surface, and underground waters, soil, rocks and sediments; besides being found within volcanic complexes, fumaroles, hot springs, gases and geothermal fluids. It was until 2010, when arsenic was detected in volcanic and sedimentary materials of the Quaternary present in the volcanic arc front of Los Maribios Mountain Range. Thus, in the La Fuente community located NE of the Momotombo-El Hoyo volcanic complex and near the Monte Galán volcanic caldera, where 112 families are supplied by groundwater, the total arsenic concentration in water from 30 dug wells, three drilled wells and a spring was determined. Arsenic concentrations ranged from 2 µg•l^-1 to 103 µg•l^-1, where 70% of the analyzed samples (24 water sources) exceed the national limit adopted, 10 µg As∙l^-1 for water for human consumption. The places with the highest temperatures (35.6 to 45.8 ° C) are the ones with the highest concentrations of arsenic (38 to 103 µg•l^-1), higher values of electrical conductivity (983 - 1140 µS∙cm^-1) and lower pH values (5.80 - 7.08 units). Community members were informed about the risk to which they are exposed by ingesting contaminated water with high values of this toxic; at the same time, safe sources of water for human consumption were identified, which were recommended to users. This research, in addition to generating scientific information, becomes a tool to support decision-making for the authorities and for local people, by using alternative water sources for human consumption and for food preparation.