Pregnancy risk from air pollution

By Gillian Tsoi

Pregnant women who are exposed to air pollution are more likely to have children with behavioural issues, according to US researchers.

They say that the offending air pollutants - called polycyclic aromatic hydrocarbons (PAH) - are strongly linked to attention problems in children.

PAH are released into the air during the burning of fossil fuels such as diesel, gasoline and coal.
Researchers at Columbia University in New York followed the children of 253 non‐smoking inner-city women who gave birth between 1999 and 2006.

They examined the women, measuring their levels of exposure to PAH. They did this by measuring the PAH concentration in the air from personal air sampling, which took place during the later stages of the mothers' pregnancy.

They also analysed blood samples taken from the mothers and blood samples taken from the umbilical cords of their newborn babies. When inhaled by the mother during pregnancy, PAH can be transferred across the placenta and bind to the DNA of the fetus, providing a biologic measure of pollutant exposure.

Mothers were later asked to assess their child's behaviour, taking into consideration symptoms of anxiety, depression, or attention problems.

The researchers discovered that high exposure of mothers to air pollutants was significantly linked with anxiety, depression and attention problems in their children.

In urban air, traffic emissions were a dominant source of the pollutants measured in the study.

"This study provides evidence that environmental levels of PAH encountered in NYC air can adversely affect child behavior. The results are of concern because attention problems and anxiety and depression have been shown to affect peer relationships and academic performance," said Prof Frederica Perera, who led the study.

Prof Perera is the director of the Columbia Center for Children's Environmental Health at Columbia University.

The study was published online in the journal Environmental Health Perspectives.

[Posted: Sun 25/03/2012]