Association between arsenic exposure from a coal-burning power plant and urinary arsenic concentrations in Prievidza District, Slovakia

To assess the arsenic exposure of a population living in the vicinity of a coal-burning power plant with high arsenic emission in the Prievidza District, Slovakia, 548 spot urine samples were speciated for inorganic As (As-inorg), monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), and their sum (As-sum). The urine samples were collected from the population of a case-control study on nonmelanoma skin cancer (NMSC). A total of 411 samples with complete As speciations and sufficient urine quality and without fish consumption were used for statistical analysis. Although current environmental As exposure and urinary As concentrations were low (median As in soil within 5 kin distance to the power plant, 41 mug/g; median urinary As-sum, 5.8 mug/L), there was a significant but weak association between As in soil and urinary As-sum (r = 0.21, p < 0.01). We performed a multivariate regression analysis to calculate adjusted regression coefficients for environmental As exposure and other determinants of urinary As. Persons living in the vicinity of the plant had 27% higher As-sum values (p < 0.01), based on elevated concentrations of the methylated species. A 32% increase of MMA occurred among subjects who consumed homegrown food (p < 0.001). NMSC cases had significantly higher levels of As-sum, DMA, and As-inorg. The methylation index As-inorg/(MMA + DMA) was about 20% lower among cases (p < 0.05) and in men (p < 0.05) compared with controls and females, respectively.