Air pollution, Acculturation and Neural Tube Defects

Abstract

Introduction: Neural tube defects are one of the most common types of birth defects. Environmental pollutants and acculturation have been associated with neural tube defects independently. The potential impact of interaction between ambient air pollution and acculturation among Hispanics in California on the risks of neural tube defects is not well understood. Methods: We investigated whether associations between traffic-related air pollutant exposure in early gestation and neural tube defects, and more specifically spina bifida, were modified by individual and neighborhood acculturation factors among 215 cases and 849 controls in the San Joaquin Valley of California, 1997-2006. Five criteria pollutant exposures, two outcomes and 7 neighborhood acculturation factors from the U.S. Census at the block group level were included for a total of 140 investigated associations. Estimates were adjusted for maternal education and multivitamin use in the first two months of pregnancy. Additional analyses were stratified by nativity. Results: Associations between air pollutants and neural tube defects were stronger in neighborhoods with more acculturation to the U.S. These associations were observed among all Hispanics and foreign-born Hispanics. The table includes the odds ratios that exclude 1 and a chi-square test of homogeneity p-value <0.05 comparing 3rd to 1st tertile of pollutant by neighborhood acculturation factors. Discussion: Neighborhood acculturation factors were modifiers of the relationship between air pollution and neural tube defects in California.