title: Ambient air pollution and risk of birth defects in Southern California.
abstract: The authors evaluated the effect of air pollution on the occurrence of birth defects ascertained by the California Birth Defects Monitoring Program in neonates and fetuses delivered in southern California in 1987-1993. By using measurements from ambient monitoring stations of carbon monoxide (CO), nitrogen dioxide, ozone, and particulate matter <10 microm in aerodynamic diameter, they calculated average monthly exposure estimates for each pregnancy. Conventional, polytomous, and hierarchical logistic regression was used to estimate odds ratios for subgroups of cardiac and orofacial defects. Odds ratios for cardiac ventricular septal defects increased in a dose-response fashion with increasing second-month CO exposure (odds ratio (OR)(2nd quartile) CO = 1.62, 95% confidence interval (CI): 1.05, 2.48; OR(3rd quartile) CO = 2.09, 95% CI: 1.19, 3.67; OR(4th quartile) CO = 2.95, 95% CI: 1.44, 6.05). Similarly, risks for aortic artery and valve defects, pulmonary artery and valve anomalies, and conotruncal defects increased with second-month ozone exposure. The study was inconclusive for other air pollutants. The authors' results are supported by the specificity of the timing of the effect and some evidence from animal data; however, this is the first known study to link ambient air pollution during a vulnerable window of development to human malformations. Confirmation by further studies is needed.
authors.affiliation: Department of Epidemiology, School of Public Health, University of California, Los Angeles, Los Angeles, CA 90095-1772, USA. britz@ucla.edu
authors.forename: Beate
authors.initials: B
authors.lastname: Ritz
authors.forename: Fei
authors.initials: F
authors.lastname: Yu
authors.forename: Scott
authors.initials: S
authors.lastname: Fruin
authors.forename: Guadalupe
authors.initials: G
authors.lastname: Chapa
authors.forename: Gary M
authors.initials: GM
authors.lastname: Shaw
authors.forename: John A
authors.initials: JA
authors.lastname: Harris
mesh_terms: D000393:Air Pollutants / Q000009:adverse effects* / Q000032:analysis; D001499:Bayes Theorem; D002140:California / Q000453:epidemiology; D002248:Carbon Monoxide / Q000009:adverse effects / Q000032:analysis; D000013:Congenital Abnormalities / Q000453:epidemiology* / Q000209:etiology*; D004781:Environmental Exposure; D004784:Environmental Monitoring; D062665:Epidemiological Monitoring; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D016015:Logistic Models; D010126:Ozone / Q000009:adverse effects / Q000032:analysis; D011247:Pregnancy; D011256:Pregnancy Outcome; D018570:Risk Assessment; D012307:Risk Factors; D014504:Urban Health
chemical_list: D000393:Air Pollutants; D010126:Ozone; D002248:Carbon Monoxide