08/22/2009 05:12 am ET | Updated May 25, 2011

Smarten Up and Stop Idling

Prenatal exposure to combustion byproducts lowers children's IQ, according to a new study conducted by researchers at the Columbia Center for Children's Environmental Health (CCCEH). New York City children, exposed to high levels of polycyclic aromatic hydrocarbons (PAHs,) the research (published in Pediatrics) showed, had full scale and verbal IQ scores that were 4.31 and 4.67 points lower, respectively, than those of less exposed children.

Motor vehicles are a major source of PAHs -- idling cars and trucks in particular. Each year, long-duration idling of truck engines consumes over 1 billion gallons of diesel fuel and emits 11 million tons of carbon dioxide, 200,000 tons of oxides of nitrogen, and 5,000 tons of particulate matter into the air.

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