Oral cleft defects and maternal exposure to ambient air pollutants in New Jersey.
BACKGROUND
Evidence links exposure to ambient air pollution during pregnancy, particularly gaseous pollutants and particulate matter, to an increased risk of adverse reproductive outcomes though the results for birth defects have been inconsistent.


METHODS
We compared estimated exposure to ambient air pollutants during early pregnancy among mothers of children with oral cleft defects (cases) to that among mothers of controls, adjusting for available risk factors from birth certificates. We obtained ambient air pollutant data from air monitoring sites in New Jersey for carbon monoxide (CO), nitrogen dioxide (NO2), ozone (O3), sulfur dioxide (SO(2)), particulate matter <10 microm in aerodynamic diameter (PM10) and particulate matter <2.5 microm in aerodynamic diameter (PM2.5). We used values from the nearest monitor (within 40 km of the residence at birth) for controls, cleft lip with or without cleft palate (CLP) and cleft palate only (CPO).


RESULTS
Based on logistic regression analyses for each contaminant and all contaminants together, there were no consistent elevated associations between selected air pollutants and cleft malformations. Quartile of CO concentration showed a consistent protective association with CPO (p < 0.01). For other contaminants, confidence intervals (95%) of the odds ratios for some quartiles excluded one. CLP showed limited evidence of an association with increasing SO(2) exposure while CPO showed weak associations with increasing O3 exposure.


CONCLUSIONS
There was little consistent evidence associating cleft malformations with maternal exposure to ambient air pollutants. Evaluating particular pollutants or disease subgroups would require more detailed measurement of exposure and classification of cleft defects.
Department of Epidemiology, UMDNJ-School of Public Health, Piscataway, NJ 08854, USA. marshaeli@umdnj.edu
Elizabeth G
EG
Marshall
Gerald
G
Harris
Daniel
D
Wartenberg
D000293:Adolescent; D000328:Adult; D000393:Air Pollutants / Q000009:adverse effects*; D000428:Alcohol Drinking / Q000453:epidemiology; D002248:Carbon Monoxide / Q000009:adverse effects; D016022:Case-Control Studies; D002971:Cleft Lip / Q000139:chemically induced* / Q000453:epidemiology; D002972:Cleft Palate / Q000139:chemically induced* / Q000453:epidemiology; D004781:Environmental Exposure; D004784:Environmental Monitoring; D062665:Epidemiological Monitoring; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D018811:Maternal Exposure / Q000009:adverse effects*; D008875:Middle Aged; D009515:New Jersey / Q000453:epidemiology; D009585:Nitrogen Dioxide / Q000009:adverse effects; D010126:Ozone / Q000009:adverse effects; D052638:Particulate Matter / Q000009:adverse effects; D011247:Pregnancy; D012907:Smoking / Q000453:epidemiology; D013458:Sulfur Dioxide / Q000009:adverse effects; D055815:Young Adult
D000393:Air Pollutants; D052638:Particulate Matter; D013458:Sulfur Dioxide; D010126:Ozone; D002248:Carbon Monoxide; D009585:Nitrogen Dioxide