Transplacental exposure to airborne polycyclic aromatic hydrocarbons and their effects on fetal growth

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous air pollutants generated by combustion sources, including diesel- and gasoline-powered motor vehicles, power plants, residential heating, cooking, and tobacco smoking (Finlayson-Pitts and Pitts 1997; 2002). Although adverse fetotoxic effects of PAHs have been suggested, the evidence on humans is conflicting. To addresses this gap in knowledge, two prospective cohort studies were conducted in non-smoking, healthy young pregnant women with no current occupational exposure. Each woman was given an in-depth health, lifestyle, and environmental exposure questionnaire and were monitored for personal exposure to benz(a)anthracene, chrysene/isochrysene, benzo(b)fluoranthene, benzo( k)fluoranthene, benzo(a)pyrene, indeno( 1,2,3-cd)pyrene, dibenz(a,h)anthracene and benzo( g,h,i)perylene and pyrene.; The mean personal PAH exposure was approximately 10-fold higher in Krakow than in NYC (39.08 vs. 3.56 ng/m3) samples. For NYCAA for KC, respectively, every 10 ng/m3 increase in PAH exposure was associated birth weight reduction of 14 g and 279 g; birth length reduction of 0.10 cm and 0.73 cm; and birth head circumference reduction of 0.04 cm, and 0.4 cm. Dose-response on birth weight was linear. Furthermore, high exposure during the first gestational month was associated with largest adverse effect on birth weight. Consistent with prior observation, no significant effect was observed among the NYC Dominicans.; Three most common PAHs in NYC cohort, benzo[g,h,i]perylene, ideno[1,2,3-c,d]pyrene, and benzo[b]fluoranthene, were respectively associated with 6- to 5-fold greater adverse effect for NYCAA compared to KC. Prior studies have shown that benzo[g,h,i]perylene and ideno[1,2,3-c,d]pyrene are predominant PAHs from gasoline combustion (Binkova, Cerna et al. 2003). These results suggest that although the airborne PAHs are 10-fold lower in NYCAA, co-exposure to multitude of xenobiotoics, maternal obesity, and preponderance of traffic-related PAHs modify the risk of PAH by contributing to the vulnerability of this population.; As birth weight reduction---as observed here both in a U.S. and European population---has been linked to later developmental and health problems, the results of this study suggest substantial health benefits worldwide from reducing PAH emissions from fossil fuels.