Contamination by As, Hg, and Sb in a region with geogenic As anomaly and subsequent human health risk characterization

Arsenic (As) is among the most harmful toxic elements to human health with severe carcinogenic and non-carcinogenic effects. The present study aims to (1) characterize a site with geogenic As anomaly (Emet basin) in Kutahya, Turkey via soil (urban, agriculture, forest; n = 53 total), water (n = 11), and agricultural product (n = 19) samples; and, (2) characterize human health risks for different receptors under specific exposure scenarios. Soil As levels were very high (range, 22.4-765 mg kg^-1). Previous literature suggested some evidence of Sb and Hg combined with As in mineral forms in the region; the present study found elevated Sb (up to 76.0 mg kg^-1) in two regions with very high As levels, but Hg concentrations were low in the region. Soils from urban/agricultural zones (representing anthropogenic impact) did not have statistically different As levels compared with forest soils (representing low/no human impact). As water concentrations were also very high (range, 14.0-729 μg L^-1), however, uptake by agricultural products was low, mostly limited to wheat (up to 0.7 mg kg^-1). Exposure assessment/risk characterization showed that non-carcinogenic risk following exposure to soils was very high for children (hazard index up to 37 under reasonable maximum exposure) as well as carcinogenic risk (probability up to 1.19E-3). The risk was even higher considering intake of water, and in this case, both for children and adults (HI, 4.0-66.6; cancer risk, 1.29E-4-1.84E-2). The potential adverse outcomes of the As anomaly in the region may be grave, thus further geochemical investigation of As speciation and mobile fractions as well as gastrointestinal As bioaccessibility supplementing probabilistic human health risk characterization are recommended.