Human Arsenic Exposure Through Food: Potential Health Consequences

Arsenic is a known carcinogen that has been associated with a myriad of other health outcomes. Pregnancy and early life represent a period of vulnerability to environmental toxicants. At present, relatively little is known about the health impacts of low levels of arsenic exposure such as occur widely in the US and elsewhere. In New Hampshire, about 40% of the population relies on unregulated water systems (e.g., private wells), and arsenic above the 10 ug/L US EPA maximum contaminant level have been detected in over 10% of these wells. We have been conducting studies to identify the primary sources of arsenic exposure, and investigate associated risks of adverse health outcomes throughout the life course. This includes studies of cancer and cardiovascular disease in adults. We also enroll pregnant women who used a private well at their home from prenatal clinics in the state. To date, our study includes over 1,500 maternal-infant pairs. In our studies and others, dietary sources, and particular rice and rice products contribute to arsenic exposure besides drinking water. Associations between rice intake and biomarkers of arsenic exposure have been observed in pregnant women, infants, younger and older children and other adults. Additionally, maternal intake of rice has been associated with infant biomarker concentrations, suggesting that maternal intake influences infant exposure. Among infants, we found consumption of rice and rice products (e.g., rice cereal) to be highly prevalent. About 80% of infants in our study were introduced to rice cereal in the first year of life, and over half of the one-year-old children were reported to be consuming rice or a rice product in the past 2 days. Notably, a significant fraction of children were reported to be eating rice snacks. With respect to health outcomes, our findings to date suggest that increased concentrations of arsenic during pregnancy is related to increased risk of infant infections, particularly respiratory infections and diarrhea, outcomes related to arsenic exposure in highly exposed populations such as Bangladesh. We also observed that higher concentrations of arsenic were related to decreased head circumference and with decreased birth weight, with the latter associations varying by infant sex and maternal pre-pregnancy body mass index. Mechanistic studies support these observations.

Speaker Information:

Margaret Karagas, Ph.D.

Professor and Chair

Department of Epidemiology

Geisel School of Medicine at Dartmouth

7927 Rubin Building

Lebanon, NH 03756

603-653-9010

Margaret.R.Karagas@Dartmouth.Edu