Arsenic Reduction in Drinking Water and Improvement in Skin Lesions: A Follow-Up Study in Bangladesh

Wei Jie Seow,¹ Wen-Chi Pan,¹ Molly L. Kile,² Andrea A. Baccarelli,¹ Quazi Quamruzzaman,³ Mahmuder Rahman,³ Golam Mahiuddin,³ Golam Mostofa,³ Xihong Lin,⁴ and David C. Christiani¹

¹Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts, USA; ²College of Public Health and Human Sciences, Oregon State University, Corvallis, Oregon, USA; ³Dhaka Community Hospital, Dhaka, Bangladesh; ⁴Department of Biostatistics, Harvard School of Public Health, Boston, Massachusetts, USA

Abstract

Background: Chronic exposure to arsenic is associated with skin lesions. However, it is not known whether reducing arsenic exposure will improve skin lesions.

Objective: We evaluated 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. We used logistic regression and generalized estimating equation (GEE) models to evaluate the association between log₁₀-transformed arsenic exposure and skin lesion persistence and severity.

Results: During the study period, 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. In the adjusted models, every log₁₀ decrease in water arsenic 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, respectively. In addition, 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 of –5.22 units; 95% CI: –8.61, –1.82).

Conclusions: Reducing arsenic exposure increased the odds that an individual with skin lesions would recover or show less severe lesions within 10 years. Reducing arsenic exposure must remain a public health priority in Bangladesh and in other regions affected by arsenic-contaminated water.

Key words: arsenic, Bangladesh, change, recovery, skin lesion. 

Environ Health Perspect 121:1733–1738 (2013). http://dx.doi.org/10.1289/ehp.1205381 [Online 10 October 2012]

Address correspondence to D.C. Christiani, Department of Environmental Health, Harvard School of Public Health, 665 Huntington Ave., Building 1, 1401, Boston, MA 02115 USA. Telephone: (617) 432-1261. Fax: (617) 432-3441. E-mail: dchris@hsph.harvard.edu

Supplemental Material is available online (http://dx.doi.org/10.1289/ehp.1205381).

This research was funded by the Harvard School of Public Health (Gene and Environment Initiative grant) and by grants P42 E016454, K01 ES017800, and P30 ES00002 from the National Institute of Environmental Health Sciences.

The authors declare they have no actual or potential competing financial interests.

Received 24 April 2012; Accepted 10 October 2012; Online 10 October 2012.