Publication Highlights Food as Source of Arsenic Exposure

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Although water is recognized and regulated as a source of exposure to arsenic, the relative contribution of dietary arsenic to total daily exposure has not been well-characterized, and few standards for acceptable levels of arsenic in food exist. Researchers at the University of Arizona (UA) set out to model the contribution of dietary inorganic and total arsenic intake to human daily exposure. The results of their study were recently published in the Journal of Exposure Science and Environmental Epidemiology.

10 p.p.b. (MCL), in two study populations, NHEXAS-AZ and BAsES.">Drinking and cooking water samples were collected from participants in several national and regional population-based studies. ICP-MS analyses for levels of arsenic in the water were performed by the UA Superfund Research Program Hazard Identification Core and U.S. Environmental Protection Agency (EPA) contract laboratories. These data were combined with dietary records in which daily exposure to inorganic and total arsenic from food was modeled to estimate total daily exposure from food, drinking water, and cooking water. Due to high levels of total (mostly organic) arsenic in seafood, subjects who reported eating seafood were excluded from the study.

Results were stratified by household tap water arsenic concentrations.  For subjects whose household tap water arsenic was below the EPA Maximum Contaminant Level (MCL) of 10 ppb, inorganic arsenic exposure from food was greater than that from drinking and cooking water combined. In households with tap water arsenic greater than 10 ppb, food contributed approximately 30% of total inorganic arsenic intake.

Lead author Margaret Kurzius-Spencer (UA Mel and Enid Zuckerman College of Public Health and College of Medicine) explains the implications of the study: “Parsing the proportion of arsenic exposure attributable to intake of food, drinking and cooking water provides a tool for assessing risk and developing a novel approach to regulation. The results of this study suggest that in order to reduce inorganic arsenic exposure in the U.S., future regulatory policy should focus more on reduction of arsenic in food than in water.”

For additional details, please see Kurzius-Spencer M, Burgess JL, Harris RB, Hartz V, Roberge J, Huang S, Hsu CH, O'Rourke MK. Contribution of diet to aggregate arsenic exposures-An analysis across populations. J Expo Sci Environ Epidemiol. 2013 Jul 17. [Epub ahead of print].