Prenatal PAHs linked to lower cognition at age five.

[Comment: "PAHs are a group of approximately 10,000 compounds, a few of which are listed above. Most PAHs in the environment are from incomplete burning of carbon-containing materials like oil, wood, garbage or coal. Many useful products such as mothballs, blacktop, and creosote wood preservatives contain PAHs. They are also found at low concentrations in some special-purpose skin creams and anti-dandruff shampoos that contain coal tars. From:  http://dhs.wisconsin.gov/eh/chemfs/fs/pah.htm" ]

Prenatal PAHs linked to lower cognition at age five.
http://www.environmentalhealthnews.org/ehs/newscience/prenatal-pahs-linked-to-lower-cognition-at-age-five/

"A child's cognitive development may be affected by exposure while in the womb to high levels of air pollutants."

----------------------------------------------
[Comment:  Here is the actual scientific study.]

Edwards, SC, W Jedrychowski, M Butscher, D Camann, A Kieltyka, E Mroz, E Flak, Z Li, S Wang, V Rauh and F Perera. Prenatal exposure to airborne polycyclic aromatic hydrocarbons and children's intelligence at age 5 in a prospective cohort study in Poland. Environmental Health Perspectives http://dx.doi.org/10.1289/ehp.0901070.  http://ehp03.niehs.nih.gov/ambra-doi-resolver/10.1289/ehp.0901070

Abstract
Background: This prospective cohort study of Caucasian mothers and children in Krakow, Poland, evaluated the role of prenatal exposure to urban air pollutants in the pathogenesis of neurobehavioral disorders.

Objectives: The objective of this study was to investigate the relationship between prenatal polycyclic aromatic hydrocarbon (PAH) exposure and child intelligence at age 5 years, controlling for potential confounders suspected to play a role in neurodevelopment.

Methods: A cohort of pregnant, healthy, non-smoking women was enrolled in Krakow, Poland, between 2001 and 2006. During pregnancy, participants were invited to complete a questionnaire and undergo 48-hour personal air monitoring to estimate their babies' exposure, and to provide a blood sample and/or a cord blood sample at the time of delivery. Two hundred and fourteen children were followed through age 5 years when their nonverbal reasoning ability was assessed using the Raven Coloured Progressive Matrices (RCPM).

Results: We found that higher (above the median of 17.96 ng/m3) prenatal exposure to airborne PAHs (range: 1.8-272.2 ng/m3) was associated with decreased RCPM scores at age 5 years, after adjusting for potential confounding variables (N=214). Further adjusting for maternal intelligence, lead or dietary PAHs did not alter this association. The reduction in RCPM score associated with high airborne PAH exposure corresponded to an estimated average decrease of 3.8 IQ points.

Conclusions: These results suggest that prenatal exposure to airborne PAHs adversely affects children's cognitive development by 5 years of age, with potential implications for school performance. They are consistent with a recent finding in a parallel cohort in New York City.