Background

Consumers are frequently exposed to arsenic in foods and considerable public and scientific concern exists regarding the potential health risks from dietary arsenic. Arsenic exists in both organic and inorganic forms and health effects are primarily attributed to inorganic forms. The most common analytical methods used to detect arsenic measure total arsenic, which includes both organic and inorganic forms. It is therefore necessary to make assumptions concerning the amounts of total arsenic found in food samples that represent inorganic arsenic. This work presents a new assessment of US dietary exposure to arsenic using data available from the FDA Total Diet Study from 2006-2008 and a series of scenarios developed to estimate inorganic arsenic levels.

Results

Total arsenic exposures were estimated for 16 population subgroups and ranged from 1.4 x10^-1 to 4.5 x10^-1 µg/kg/day. The population subgroup with the highest exposure to total arsenic was 2 year-old children. The major food group contributors to total arsenic exposure for the general US population were marine sources, which accounted for 69 percent of the total arsenic exposure, and grains, legumes and seeds, which accounted for 20 percent. The highest inorganic arsenic exposures occurred for 2 year-old children and ranged from to 1.1 x10^-1 µg/kg/day to 2.4 x10^-1 µg/kg/day. Inorganic arsenic exposures for the 2 year-olds were 3.3 to 4.8 times higher than inorganic arsenic exposures for the general population. Under Scenario 5, which assumed that 70 percent of total arsenic from terrestrial sources and 10 percent of total arsenic from marine sources existed as inorganic arsenic, the most important food group contributors to inorganic arsenic for 2 years-olds were grains, legumes and seeds (50 percent), beverages (14 percent), marine sources (13 percent) and snacks and breakfast cereals (12 percent).

Conclusions

The exposures estimates obtained in this work are below the EPA’s established RfD of 0.3 µg/kg/day for inorganic arsenic and below EFSA’s health concern level of 0.3 to 8.0 µg/kg/day. To improve the accuracy of future arsenic risk assessments, studies should incorporate specific analytical data measuring inorganic arsenic from foods contributing the most to inorganic arsenic exposure.