Evaluation of low-to-moderate arsenic exposure, metabolism and skin lesions in a Turkish rural population exposed through drinking water

Background: There is no human data regarding the exposure, metabolism and potential health effects of arsenic (As) contamination in drinking water in the Central Anatolian region of Turkey. Methods: Residents in ten villages with drinking water of total As (T-As) level >50 mu g L-1 and 10-50 mu g L-1 were selected as an exposed group (n = 420) and <10 mu g L-1 as an unexposed group (n = 185). Time-weighted average-As (TWA-As) intake was calculated from T-As analysis of drinking water samples. Concentrations of T-As in urine and hair samples, urinary As species [i.e., As(III), As(V), MMA(V) and DMA(V], and some micronutrients in serum samples of residents of the study area were determined. Primary and secondary methylation indices (PMI and SMI, respectively) were assessed from urinary As species concentrations and the presence of skin lesion was examined. Results: TWA-As intake was found as 75 mu g L-1 in the exposed group. Urinary and hair T-As and urinary As species concentrations were significantly higher in the exposed group (P < 0.05). The PMI and SMI values revealed that methylation capacities of the residents were efficient and that there was no saturation in As metabolism. No significant increase was observed in the frequency of skin lesions (hyperpigmentation, hypopigmentation, keratosis) of the exposed group (P > 0.05). Only frequency of keratosis either at the hand or foot was higher in individuals with hair As concentration >1 mu g g(-1) (P < 0.05). Conclusions: Individuals living in the study area were chronically exposed to low-to-moderate As due to geological contamination in drinking water. No significant increase was observed in the frequency of skin lesions. Because of the controversy surrounding the health risks of low-to-moderate As exposure, it is critical to initiate long-term follow-up studies on health effects in this region.