A link between air pollution exposure during pregnancy and subsequent childhood behavioural problems has been revealed by a US-based study.
Air pollution is a significant health threat. According to the WHO, in 2012 one in eight deaths were linked to poor air quality. "Air pollution is now the world’s largest single environmental health risk," it says.
But premature death is not the only risk arising from breathing bad air. Columbia University Medical Centre, New York, researcher Amy Margolis has found that babies exposed to pollution while still inside the womb are at increased risk of developing behavioural problems as they grow up.
In the study 462 mother-baby pairs were followed up over more than a decade.
Blood samples from the mother collected while she was pregnant were used to measure exposure to a class of compounds called polycyclic aromatic hydrocarbons (PAHs), which are a common constituent of emissions from vehicles, coal and oil burning, home heating and even tobacco smoke.
At all ages, and significantly so from the age of nine, children whose mothers had detectable blood PAHs during pregnancy had significantly worse DESR scores than children whose mothers tested negative.
These deficits in self-regulation may, in turn, predispose adolescents towards increased risk-taking behaviours.
They speculate that PAH exposure may damage or retard the development of sensitive circuits in the developing brain that are relevant to motor and attentional function.
"This study indicates that prenatal exposure to air pollution impacts development of self-regulation and as such may underlie the development of many childhood psychopathologies that derive from deficits in self-regulation, such as ADHD, OCD, substance use disorders, and eating disorders," says Margolis.
Weird. Isn't the placenta supposed to provide a barrier between the fetus and the nasty world outside?