Ira Tager, M.D.
University of California, Berkeley
NIEHS Grant P20ES018173
Women in the San Joaquin Valley of California who were exposed to the highest levels of carbon monoxide, nitrogen oxide, or nitrogen dioxide during their first eight weeks of pregnancy were more likely to have a baby with spina bifida or anencephaly neural tube defects than women with the lowest exposure, according to an NIEHS-supported study. These results add evidence of a link between air pollution exposure and some birth defects.
The researchers used data from the California Center of the National Birth Defects Prevention Study and the NIEHS-funded Children’ s Health and Air Pollution Study to investigate whether air pollution in the San Joaquin Valley of California is associated with risks of five types of birth defects. After controlling for factors such as maternal race/ethnicity, education, and multivitamin use, the researchers observed increased odds of spina bifida or anencephaly neural tube defects in the babies of women who experienced the highest levels of carbon monoxide, nitrogen oxide, or nitrogen dioxide exposure during their first eight weeks of pregnancy. Ozone exposure was associated with decreased odds of neural tube defects.
The adjusted odds ratio was 1.9 (95 percent confidence interval: 1.1, 3.2) for neural tube defects among those with the highest quartile of carbon monoxide exposure compared with those with the lowest exposure. Nitrogen oxide exposure showed similar effects with the highest quartile of nitrogen oxide exposure associated with neural tube defects (adjusted odds ratio = 1.8, 95 percent confidence interval: 1.1, 2.8), and the adjusted odds ratio for the highest quartile of nitrogen dioxide exposure was 1.7 (95 percent confidence interval: 1.1, 2.7).
Citation: Padula AM, Tager IB, Carmichael SL, Hammond SK, Lurmann F, Shaw GM. 2013. The association of ambient air pollution and traffic exposures with selected congenital anomalies in the San Joaquin Valley of California. Am J Epidemiol 177(10):1074-1085.