Does Arsenic Exposure Have a Role in Development of Thyroid Disease?

Abstract

Abstract Background: Several animal studies indicate arsenic toxicity can affect thyroid hormone metabolism. There is no study in the English scientific literature of the relationship between thyroid disease and arsenic exposure in human population. The Indian state of West Bengal is affected by arsenic contamination of ground water. According to the World Health Organisation 6 of the 23 districts of West Bengal are higher affected areas. Objectives: To study the role of arsenic in development of thyroid disease. Methods: Arsenic exposure in seven patients with thyroid disease was estimated by Inductive Coupled Plasma Mass Spectroscopy (ICP-MS) of hair and nail samples. Results: Of the seven patients 2 were male and 5 were female. Two patients had thyroid malignancy (papillary carcinoma) while the rest had benign thyroid disease. Six out of the seven were residents of higher arsenic affected districts of West Bengal. One patient with a thyroid adenoma had elevated concentration of arsenic in hair (1.19 mg/kg). A second patient with of follicular adenoma had sub-clinical hypothyroidism at the time of the survey. Conclusion: This small study suggests that arsenic exposure may be associated with the development of thyroid disease. A larger study with adequate controls is warranted to establish the true role of arsenic in the aetio-pathogenesis of thyroid disorders.