Arsenic and Rice: Translating Research to Address Health Care Providers' Needs

Abstract

From the Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI; Department of Pediatrics, UCSF Benioff Children’s Hospital Oakland, Oakland, CA; Western States Pediatric Environmental Health Specialty Unit, University of California, San Francisco, CA; Children’s Environmental Health and Disease Prevention Research Center at Dartmouth; Department of Biological Sciences, Dartmouth College, Hanover, NH; Arsenic Health Effects Research Program, University of California, Berkeley, CA; and Department of Epidemiology, Geisel School of Medicine at Dartmouth, Hanover, NH A rsenic is a naturally occurring element and anthropogenic contaminant present in 2 general forms: inorganic and organic. Inorganic arsenic is considered highly toxic to humans. The International Agency for Research on Cancer, Agency for Toxic Substances and Disease Registry, and the US Environmental Protection Agency (EPA) all classify inorganic arsenic as a human carcinogen. The health effects of organic forms are not fully understood; however, some of the organic forms also may have toxic and potentially carcinogenic properties. Children can be exposed to arsenic in multiple ways. An important source of chronic exposure to inorganic arsenic worldwide is contaminated drinking water. However, because municipal water systems in the US are regulated to meet federal standards, the primary exposure to arsenic for most people in the US is food. One food known to be particularly high in arsenic is rice, a staple for much of the world’s population. Rice grown throughout the world contains arsenic, particularly US-grown rice. Though the amount and forms of arsenic found in different rice cultivars vary, the average levels of inorganic arsenic detected in rice are high enough to raise questions about potential health impacts, including for children. Dietary exposure to arsenic is of particular concern for children for several reasons. First, exposure to arsenic and other chemicals during critical windows of vulnerability in early childhood may result in greater health risks. Second, children typically have greater exposure to contaminants per unit body weight than adults in part because of their greater consumption rates and high caloric needs. Finally, children may also be more exposed to contaminants unique to certain foods because of their selective eating patterns and limited dietary choices. For example, rice is used in many first foods and is a key component of numerous processed foods marketed specifically to children. Thus, it is important for clinicians to become familiar with childhood arsenic exposure, potential health effects, and strategies to reduce exposure. Given the concern about children’s consumption of arsenic in rice, the US Food and Drug Administration (FDA) has published brief statements on this topic to