A follow-up study of the development of skin lesions associated with arsenic exposure duration.

Little information about the development of skin lesions in relation to arsenic exposure duration is available. Therefore, skin lesions in a cohort from the Bameng region of China were diagnosed in 2012 and 2017. The results indicated that the prevalence of hyperkeratosis, pigmentation and depigmentation in 2017 was 64.67, 6.67 and 12.67%. There were 42 and 34% of male subjects and female subjects suffered from skin lesions in 2012. Their morbidity rates were 10.43 and 8.98 per 1000 person-years. In 2017, the values were significantly increased. The prevalence and morbidity rate of skin lesions were positively correlated with age and arsenic levels in drinking water. Males had higher prevalence of skin lesions compared with female. However, the ≤ 40 years female group had higher prevalence of skin lesions. In addition, the increased rate of skin lesions prevalence was negatively correlated with arsenic levels in drinking water. The odds ratios (ORs) showed that the risks of skin lesions were positively associated with the proportion of inorganic arsenic (%iAs) and monomethylarsonic acid (%MMA) in urine, and negatively correlated with arsenic methylation capacity in both 2012 and 2017. It can be concluded that females immigrated from other areas were more susceptible to developing skin lesions. A certain cumulative arsenic exposure dose, which may be existing, significantly increased the prevalence of skin lesions. Longer arsenic exposure duration might elevate the toxicity of iAs to skin lesions and reduce the positive effects of arsenic methylation capacity on skin lesions.