Biomarkers, skin lesions and mortality associated with well-water arsenic in Inner Mongolia

Arsenic contamination in drinking water affects millions of people worldwide. In addition to lung, bladder and skin cancer, there is increasing evidence of non-cancer health effects. In the early 1980's, parts of the Inner Mongolia region of China shifted from surface water and shallow wells for drinking water to deeper wells. Many of these deeper wells were contaminated by arsenic. In 1999, the US EPA in collaboration with the Inner Mongolia Centers for Endemic Disease Research and Control began studies of biomarkers and health effects. Nearly 2,000 household wells were tested for arsenic which ranged from below detection to nearly 1,000 parts per billion. At a single village, a complete census was conducted and causes of mortality were determined over an eight-year period. Arsenic exposure was associated with numerous biomarkers including expression of DNA repair genes, peripheral neuropathy and increased mortality. A biomarker of diabetes, glycated hemoglobin (HbA1c), and biomarker of heart disease, prolonged QT-interval, showed a linear dose-response relationship with well-water arsenic, nail arsenic and urinary arsenic. Skin lesions were also noted at low to moderate exposures (50 ppb). In summary, numerous health effects were evident among residents of Inner Mongolia with moderate levels of arsenic in well water.