College of Public Health and Human Sciences

Background: Chronic exposure to arsenic is associated with skin lesions. However, it is not known whether reducing arsenic exposure will improve skin lesions. Objectives: To evaluate the association between reduced arsenic exposures and skin lesion recovery over time. Methods: A follow-up study of 550 individuals was conducted in 2009-2011 on a baseline population of skin lesion cases (N=900) previously enrolled in Bangladesh in 2001-2003. Arsenic in drinking water and toenails, and skin lesion status and severity were ascertained at baseline and follow-up. Logistic regression and generalized estimating equation (GEE) models were used to evaluate the association between log10-transformed arsenic exposure and skin lesion persistence and severity. Results: Water arsenic concentrations decreased in this population by 41% overall, and 65 individuals who had skin lesions at baseline had no identifiable lesions at follow-up. Every log10 decrease in water and toenail arsenic was associated with 22% (odds ratio (OR) = 1.22; 95% CI: 0.85, 1.78) and 4.5 times (OR = 4.49; 95% CI: 1.94, 11.1) relative increase in skin lesion recovery in adjusted models, respectively. Additionally, lower baseline arsenic levels were significantly associated with increased odds of recovery. A log10 decrease in toenail arsenic from baseline to follow-up was also significantly associated with reduced skin lesion severity in cases over time (mean score change = -5.22 units; 95% CI: -8.61, -1.82). Conclusions: Reducing arsenic exposure increased the odds that individual with skin lesions would recover or show less severe lesions within ten years. Reducing arsenic exposure must remain a public health priority in Bangladesh and in other regions affected by arsenic contaminated water.