New York, April 30 (IANS): Material hardship can increase the adverse affects of physical "stressors" like air pollutants as researchers have found that the toxic combination of air pollution and poverty could lower the intelligence quotient (IQ) of your kid.

The findings showed that children born to mothers experiencing economic hardship, who were also exposed during pregnancy to high levels of PAH (polycyclic aromatic hydrocarbons), scored significantly lower on IQ tests at age 5 compared with children born to mothers with greater economic security and less exposure to the pollutants.

"The findings support policy interventions to reduce air pollution exposure in urban areas as well as programs to screen women early in pregnancy to identify those in need of psychological or material support," said senior study author Frederica Perera from the Columbia University in the US.

PAH are ubiquitous in the environment from emissions from motor vehicles, oil, and coal-burning for home heating and power generation, tobacco smoke, and other combustion sources.

Material hardship is a measure used to assess an individual's unmet basic needs with regard to food, clothing, and housing.

For the study, the researchers followed 276 mother-child pairs from pregnancy through early childhood in New York City.

The researchers used the Wechsler Intelligence Scale for Children to assess IQ.

Children of mothers who reported greater material hardship, and were exposed to high levels of PAH during pregnancy scored lower on tests of full scale IQ, perceptual reasoning, and working memory.

The study appeared in the journal Neurotoxicology and Teratology.