Significance of the prime factors regulating arsenic toxicity and associated health risk: a hypothesis-based investigation in a critically exposed population of West Bengal, India.

Abstract

The suffering from arsenic toxicity is a long-standing concern in Asian countries. The role of the key factors (arsenic intake, age and sex) regulating arsenic toxicity is aimed to evaluate for a severely exposed population from Murshidabad district, West Bengal. Mean arsenic concentrations in drinking water supplied through tube well, Sajaldhara treatment plant and pipeline were observed as 208, 27 and 54µg/l, respectively. Urinary arsenic concentration had been observed as < 3-42.1, < 3-56.2 and < 3-80µg/l in children, teenagers and adults, respectively. Mean concentrations of hair and nail arsenic were found to be 0.84 and 2.38mg/kg; 3.07 and 6.18mg/kg; and 4.41 and 9.07mg/kg, respectively, for the studied age-groups. Water arsenic was found to be associated with hair and nail (r = 0.57 and 0.60), higher than urine (r = 0.37). Arsenic deposition in biomarkers appeared to be dependent on age; however, it is independent of sex. Principal component analysis showed a direct relationship between dietary intake of arsenic and chronic biomarkers. Nail was proved as the most fitted biomarker of arsenic toxicity by Dunn's post hoc test. Monte Carlo sensitivity analysis and cluster analysis showed that the most significant factor regulating health risk is 'concentration of arsenic' than 'exposure duration', 'body weight' and 'intake rate'. The contribution of arsenic concentration towards calculated health risk was highest in teenagers (45.5-61.2%), followed by adults (47.8-49%) and children (21-27.6%). Regular and sufficient access to arsenic-safe drinking water is an immediate need for the affected population.