article_snippet: The US study looked at neurotoxic PAH - polycyclic aromatic hydrocarbons - and The US study effects on the brains of inner city kids.
article_snippet: Earlier studies has shown PAH can readily cross the placenta and affects an unborn child's brain and animal studies showed that prenatal exposure impaired the development of behaviour, learning and memory.
article_snippet: The study by the Institute for the Developing Mind at Children's Hospital Los Angeles and Columbia University's Centre for Children's Environmental Health tested the effects on brain structure of PAH exposure during the final trimester of pregnancy.
article_snippet: Our findings suggest that PAH are contributors to ADHD and other behavioural problems due to the pollutants' disruptive effects on early brain development.'
article_snippet: Postnatal PAH exposure - measured at age five - was found to contribute to additional disturbances in development of white matter in the dorsal prefrontal region of the brain, which is associated with concentration, reasoning, judgment, and problem-solving ability.
article_snippet: Prof Peterson explained that the morphological features associated with ADHD symptoms in this community sample differed from those previously reported in youth with the disorder, suggesting that exposure to high levels of PAH may produce a specific subtype of ADHD.
article_snippet: If confirmed, Our findings have important public health implications, given the ubiquity of PAH in air pollutants in the general population.'