Blood and urine levels of long half-life toxicants by nativity among immigrants to the United States

Abstract

One's place of birth is a major determinant of his or her exposure to environmental toxicants. By understanding biological burdens of long half-life toxicants by race and nativity we can better understand geographic variation in toxicant distribution. We used the National Health and Nutrition Examination Survey (1999–2006) biomonitoring data to examine differences in blood and urine levels of long half-life environmental toxicants of foreign-born relative to US-born people by race/ethnicity. We log transformed blood and urine measures of 51 environmental toxicants. We then used “seemingly unrelated regression,” a robust technique for making multiple comparisons across a group of variables with correlated error terms, to examine differences in blood and urine toxicants by nativity and race. We found that, compared to native-born Americans, the foreign-born are generally more likely to be exposed to metals (p < 0.001) and organochlorine pesticides (p < 0.001), but less likely to be exposed to dioxin-like compounds (p < 0.001) or polyflourinated compounds (p < 0.001). While levels of toxicants varied greatly by region of birth, US-born participants had consistently higher levels of dioxin-like compounds and polyflourinated compounds