Traffic-related atmospheric pollutants levels during pregnancy and offspring's term birth weight: a study relying on a land-use regression exposure model.
BACKGROUND
Some studies have suggested that particulate matter (PM) levels during pregnancy may be associated with birth weight. Road traffic is a major source of fine PM (PM with aero-dynamic diameter < 2.5 microm; PM(2.5)).


OBJECTIVE
We determined to characterize the influence of maternal exposure to atmospheric pollutants due to road traffic and urban activities on offspring term birth weight.


METHODS
Women from a birth cohort [the LISA (Influences of Lifestyle Related Factors on the Human Immune System and Development of Allergies in Children) cohort] who delivered a non-premature baby with a birth weight > 2,500 g in Munich metropolitan area were included. We assessed PM(2.5), PM(2.5) absorbance (which depends on the blackness of PM(2.5), a marker of traffic-related air pollution), and nitrogen dioxide levels using a land-use regression model, taking into account the type and length of roads, population density, land coverage around the home address, and temporal variations in pollution during pregnancy. Using Poisson regression, we estimated prevalence ratios (PR) of birth weight < 3,000 g, adjusted for gestational duration, sex, maternal smoking, height, weight, and education.


RESULTS
Exposure was defined for 1,016 births. Taking the lowest quartile of exposure during pregnancy as a reference, the PR of birth weight < 3,000 g associated with the highest quartile was 1.7 for PM(2.5) [95% confidence interval (CI), 1.2-2.7], 1.8 for PM(2.5) absorbance (95% CI, 1.1-2.7), and 1.2 for NO(2) (95% CI, 0.7-1.7). The PR associated with an increase of 1 microg/m(3) in PM(2.5) levels was 1.13 (95% CI, 1.00-1.29).


CONCLUSIONS
Increases in PM(2.5) levels and PM(2.5) absorbance were associated with decreases in term birth weight. Traffic-related air pollutants may have adverse effects on birth weight.
Slama
Rémy
R
GSF-National Research Center for Environment and Health, Institute of Epidemiology, Neuherberg, Germany. slama@vjf.inserm.fr
Morgenstern
Verena
V
Cyrys
Josef
J
Zutavern
Anne
A
Herbarth
Olf
O
Wichmann
Heinz-Erich
HE
Heinrich
Joachim
J
D000393:Air Pollutants / Q000032:analysis / Q000633:toxicity*; D001724:Birth Weight / Q000187:drug effects*; D005260:Female; D040362:Geographic Information Systems; D005858:Germany; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D018811:Maternal Exposure / Q000009:adverse effects*; D008962:Models, Theoretical; D009585:Nitrogen Dioxide / Q000032:analysis; D052638:Particulate Matter / Q000032:analysis / Q000633:toxicity*; D011247:Pregnancy; D012044:Regression Analysis; D001335:Vehicle Emissions / Q000032:analysis / Q000633:toxicity*