Comparison of drinking water, raw rice and cooking of rice as arsenic exposure routes in three contrasting areas of West Bengal, India

Abstract

Remediation aimed at reducing human exposure to groundwater arsenic in West Bengal, one of the regions most impacted by this environmental hazard, are currently largely focussed on reducing arsenic in drinking water. Rice and cooking of rice, however, have also been identified as important or potentially important exposure routes. Quantifying the relative importance of these exposure routes is critically required to inform the prioritisation and selection of remediation strategies. The aim of our study, therefore, was to determine the relative contributions of drinking water, rice and cooking of rice to human exposure in three contrasting areas of West Bengal with different overall levels of exposure to arsenic, viz. high (Bhawangola-I Block, Murshidibad District), moderate (Chakdha Block, Nadia District) and low (Khejuri-I Block, Midnapur District). Arsenic exposure from water was highly variable, median exposures being 0.02 μg/kg/d (Midnapur), 0.77 μg/kg/d (Nadia) and 2.03 μg/kg/d (Murshidabad). In contrast arsenic exposure from cooked rice was relatively uniform, with median exposures being 0.30 μg/kg/d (Midnapur), 0.50 μg/kg/d (Nadia) and 0.84 μg/kg/d (Murshidabad). Cooking rice typically resulted in arsenic exposures of lower magnitude, indeed in Midnapur, median exposure from cooking was slightly negative. Water was the dominant route of exposure in Murshidabad, both water and rice were major exposure routes in Nadia, whereas rice was the dominant exposure route in Midnapur. Notwithstanding the differences in balance of exposure routes, median excess lifetime cancer risk for all the blocks were found to exceed the USEPA regulatory threshold target cancer risk level of 10(-4)-10(-6). The difference in balance of exposure routes indicate a difference in balance of remediation approaches in the three districts.

Arsenic Adsorption onto Minerals: Connecting Experimental Observations with Density Functional Theory Calculations

“…Groundwater that contains As concentrations >10 μg/L limit set by the World Health Organization (WHO) places more than ten million people at risk from arsenicosis. Locales ranging from Southern Bangladesh, India, Argentina, Chile, and Vietnam have groundwater sources with As concentrations >10 μg/L [2,3,6,25,26,[28][29][30][31][32][33].…”

Inorganic arsenic in Chinese food and its cancer risk

“…The principal exposures routes for As are via drinking water, foods and inhaled particulates (Mondal et al, 2010), with many studies detailing the importance of the food pathway to overall As body burdens (Georgopoulos et al, 2007;Meacher et al, 2002;Mondal et al, 2010;Schoof et al, 1999;Xue et al, 2010). In West Bengal (India) it has been shown that even for populations exposed to high As levels in the drinking water, rice constitutes a major source of iAs in the diet (Mondal and Polya, 2008).…”

Diarrhoeal Health Risks Attributable to Water-Borne-Pathogens in Arsenic-Mitigated Drinking Water in West Bengal are Largely Independent of the Microbiological Quality of the Supplied Water

“…In each incubation cycle we included a negative control consisting of sterile water, processed in the same way as the samples. We analyzed water samples for total arsenic by inductively coupled plasma mass spectrometry (ICP-MS) (Agilent 7500 Series ICP-MS) at the University of Manchester following the method outlined by Mondal et al [14].…”

“…The area selected for this study, Chakdha Block of Nadia District, West Bengal fulfils the requirements of being (i) geographically focused; (ii) an arsenic impacted area [1,13,14]; (iii) the site of several different arsenic mitigation strategies [15]; (iv) well studied with background information available [14][15][16] and (v) straightforward logistically. We calculated disability adjusted life years (DALYs) as a mean of comparing disease burden arising from the two water-borne hazards: arsenic and pathogens.…”