Air Pollution Linked to Neural Tube Defects
Editors' Recommendations
Drug & Reference Information
Early maternal exposure to high levels of air pollution can cause neural tube defects, according to new Stanford University research published online March 28 in the American Journal of Epidemiology.
Analyzing air quality and birth defect data for women living in one of the country's smoggiest areas — California's San Joaquin Valley — Amy Padula, PhD, from the Department of Pediatrics, School of Medicine, Stanford University, California, and colleagues found a positive correlation between neural tube defects and maternal exposure to carbon monoxide, nitrogen oxide, and nitrogen dioxide during the first 2 months of pregnancy.
The findings add to the limited body of evidence linking air pollution and birth defects, the etiology of which remains largely unknown. The results are supported by the known biologic effects of smoking on fetal development, according to the authors.
"If these associations are confirmed, this work offers an avenue for a potential intervention for reducing birth defects," Dr. Padula said in a university news release.
"In addition, for our colleagues who are bench scientists, this work gives them an opportunity to think about what pollution exposures might mean mechanistically," said senior author Gary Shaw, PhD, professor of neonatal and developmental medicine at the university. "It could give them a better understanding of the details of human development."
The authors note that prior studies have produced conflicting results and been limited by methodology; the current research is the first to evaluate a woman's pollution exposure in early pregnancy rather than at birth.
For the study, the investigators analyzed environmental data collected between 1997 and 2006 for 806 mothers whose infants/fetuses had congenital anomalies, including neural tube defects (anencephaly and spina bifida; n = 215) and for 849 women whose babies had no such complications.
The majority of participants were Hispanic, and almost half were younger than 25 years at delivery and had at least a high school education. Their exposure was assessed using residence-based traffic metrics and data collected by the Environmental Protection Agency as part of federally mandated air-quality monitoring for pollutants, including carbon monoxide, nitrogen oxide, nitrogen dioxide, particulate matter, and ozone.
After adjusting for maternal race/ethnicity, education, and multivitamin use, the researchers found that mothers in the highest quartile level for exposure to carbon monoxide during the first 8 weeks of pregnancy were almost twice as likely to have babies with neural tube defects (odds ratio [OR], 1.9; 95% confidence interval [CI], 1.1 - 3.2) as those with the lowest exposure.
Nitrogen oxide and nitrogen dioxide were also linked to increased risks for these defects (adjusted OR, 1.8 [95% CI, 1.1 - 2.8], and 1.7 [95% CI, 1.1 - 2.7], respectively). The link between nitrogen oxide exposure and anencephaly was particularly strong (adjusted OR, 2.8; 95% CI, 1.3 - 5.9). In contrast, exposure to ozone was linked to a decreased risk for neural tube defects (adjusted OR, 0.6; 95% CI, 0.4 - 0.9).
Further studies are needed to evaluate the combined effects of multiple pollutants and to examine the effects of additional traffic-related pollutants, such as polycyclic aromatic hydrocarbon, the authors note.
The study was funded by the National Institute for Environmental Health Science, the US Environmental Protection Agency, and the Centers for Disease Control and Prevention.
Am J Epidemiol. Published online March 28, 2013. Abstract
0 comments:
Post a Comment