Arsenic In Surface Waters In The Central Part Of The North Caucasus And Correspondent Health Risk Assessment

Abstract

Arsenic is ranked as a significant global health hazard associated with potable water. The present study assesses the arsenic pollution of the surface waters in the mountainous regions of the central part of the North Caucasus due to the presence of geochemical anomalies and the potential health risk by its consumption for the residents. The studies were carried out from 2016 to 2022. The surface waters of 5 main rivers of the region (Kuban, Malka, Baksan, Chegem and Cherek) with their main tributaries have been studied. Samples were taken during the period of intensive melting of glaciers (summer). The determination of the soluble form of arsenic was carried out using the method of atomic absorption spectrometry. In general, arsenic concentrations in this region are lower than Clark values for river waters. Along with this, watercourses with high and very high concentrations of arsenic have been identified. Elevated concentrations of arsenic in surface waters spatially coincide with the location of geochemical anomalies. The most polluted is the Baksan River. The levels of surface waters pollution from natural and anthropogenic sources are almost the same (up to 100 µg/dm3). In this regard, an assessment of the health hazard was carried out. For residents receiving drinking water from wells located at the southern foot of Elbrus, the carcinogenic risk for adults was 4.51×10-4, which is unacceptable for the general population. The non–carcinogenic risk was 1.00 - the maximum permissible risk causing concern.