Rice Consumption and Urinary Arsenic Concentrations in U.S. Children

BACKGROUND: In adult populations, emerging evidence indicates that humans are exposed to arsenic by ingestion of contaminated foods such as rice, grains, and juice; yet little is known about arsenic exposure among children. OBJECTIVES: Our goal was to determine whether rice consumption contributes to arsenic exposure in U.S. children. METHODS: We used data from the nationally representative National Health and Nutrition Examination Survey (NHANES) to examine the relationship between rice consumption (measured in 0.25 cups of cooked rice per day) over a 24-hr period and subsequent urinary arsenic concentration among the 2,323 children (6-17 years of age) who participated in NHANES from 2003 to 2008. We examined total urinary arsenic (excluding arsenobetaine and arsenocholine) and dimethylarsinic acid (DMA) concentrations overall and by age group: 6-11 years and 12-17 years. RESULTS: The median [interquartile range (IQR)] total urinary arsenic concentration among children who reported consuming rice was 8.9 mu g/L (IQR: 5.3-15.6) compared with 5.5 mu g/L (IQR: 3.1-8.4) among those who did not consume rice. After adjusting for potentially confounding factors, and restricting the study to participants who did not consume seafood in the preceding 24 hr, total urinary arsenic concentration increased 14.2% (95% confidence interval: 11.3, 17.1%) with each 0.25 cup increase in cooked rice consumption. CONCLUSIONS: Our study suggests that rice consumption is a potential source of arsenic exposure in U.S. children.