Mum's exposure to urban pollutants can lower child's IQ
Thursday, 23 July 2009, 17:07 IST
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Washington: A mother's exposure to urban air pollutants can lower a child's intelligence quotient or IQ, says a new study. These pollutants include polycyclic aromatic hydrocarbons or PAHs, chemicals released into the air from the burning of coal, diesel, oil and gas, or other organic substances such as tobacco. Motor vehicles are a major source of PAHs. The study, funded by the National Institute of Environmental Health Sciences (NIEHS), found that children exposed to high levels of PAHs in New York City had full-scale and verbal IQ scores that were 4.31 and 4.67 points lower than those of less exposed children. "This research clearly shows that environmental PAHs at levels encountered in an urban setting can adversely affect a child's IQ," said Linda Birnbaum, director of NIEHS. "This is the first study to report an association between PAH exposure and IQ, and it should serve as a warning bell to us all. We need to do more to prevent environmental exposures from harming our children," she said. The study was conducted by scientists from the Columbia University Centre for Children's Environmental Health. It included children who were born to non-smoking black and Dominican-American women age 18 to 35 who resided in Harlem, New York. The children were followed from utero to five years of age. The mothers wore personal air monitors during pregnancy to measure exposure to PAHs and they responded to questionnaires. At five years of age, 249 children were given an intelligence test known as the Wechsler Pre-school and Primary Scale of the Intelligence, which provides verbal, performance and full-scale IQ scores. The test is regarded as a well validated, reliable and sensitive instrument for assessing intelligence. The researchers developed models to calculate the associations between prenatal PAH exposure and IQ.
Source: IANS
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