Mothers exposed to urban air pollutants are reducing their children's intelligence, according to a new US study.
Researchers at the Columbia Center for Children's Environmental Health (CCCEH) at the Mailman School of Public Health found that prenatal exposure to environmental pollutants known as polycyclic aromatic hydrocarbons (PAHs) can adversely affect a child's IQ.
The study, part funded by the US Environmental Protection Agency, looked at children in New York City born to non-smoking women between the ages of 18-35.
The children were followed from pregnancy, during which time the mothers worse personal air monitors, until to 5 years of age. The air monitors measured their exposure to PAHs.
At 5 years of age, 249 children were given an IQ test with 140 of them classified as having high PAH exposure. Those exposed to high levels of PAHs had full scale and verbal IQ scores between 4.31 and 4.67 lower than those of less exposed children.
'This finding is of concern because IQ is an important predictor of future academic performance, and PAHs are widespread in urban environments and throughout the world,' said study author Dr Frederica Perera.
CCCEH study in full