Gestational exposure to urban air pollution related to a decrease in cord blood vitamin d levels.
BACKGROUND
Vitamin D deficiency has been implicated in the increased risk of several diseases. Exposure to air pollution has been suggested as a contributor to vitamin D deficiency. However, studies that have examined the effects of air pollution on vitamin D status are few and have never focused on prenatal life as an exposure window.


OBJECTIVE
Our aim was to investigate the associations between gestational exposure to urban air pollutants and 25-hydroxyvitamin D [25(OH)D] cord blood serum level in 375 mother-child pairs of the EDEN birth cohort.


METHODS
The Atmospheric Dispersion Modelling System (ADMS-Urban) pollution model, a validated dispersion model combining data on traffic conditions, topography, meteorology, and background pollution, was used to assess the concentrations of two major urban pollutants, particulate matter less than 10 μm in diameter (PM(10)) and nitrogen dioxide (NO(2)), at the mother's home address during pregnancy. Cord blood samples were collected at birth and were analyzed for levels of 25(OH)D.


RESULTS
Maternal exposure to ambient urban levels of NO(2) and PM(10) during the whole pregnancy was a strong predictor of low vitamin D status in newborns. After adjustment, log-transformed 25(OH)D decreased by 0.15 U (P = 0.05) and 0.41 U (P = 0.04) for a 10-μg/m(3) increase in NO(2) and PM(10) pregnancy levels, respectively. The association was strongest for third-trimester exposures (P = 0.0003 and P = 0.004 for NO(2) and PM(10), respectively).


CONCLUSIONS
Gestational exposure to ambient urban air pollution, especially during late pregnancy, may contribute to lower vitamin D levels in offspring. This could affect the child's risk of developing diseases later in life.
Epidemiology of Allergic and Respiratory Diseases Unité Mixte de Recherche-S 707 Institut National de la Santé et de la Recherche Médicale and Université Pierre et Marie Curie (UPMC) Paris 6, Medical School Saint-Antoine, 27 Rue Chaligny 75571 Paris Cedex 12, France. baiz@u707.jussieu.fr
Nour
N
Baïz
Patricia
P
Dargent-Molina
John D
JD
Wark
Jean-Claude
JC
Souberbielle
Rémy
R
Slama
Isabella
I
Annesi-Maesano
D000328:Adult; D000393:Air Pollutants / Q000009:adverse effects*; D000397:Air Pollution / Q000009:adverse effects*; D015331:Cohort Studies; D005260:Female; D005312:Fetal Blood / Q000737:chemistry*; D006801:Humans; D007231:Infant, Newborn; D011247:Pregnancy; D014807:Vitamin D / Q000032:analysis*; D014808:Vitamin D Deficiency / Q000209:etiology*
D000393:Air Pollutants; D014807:Vitamin D