Study links kids' lower test scores to secondhand smoke
January 04, 2005
USA TODAY

Children exposed to secondhand smoke have lower test scores in reading, math and problem-solving, according to research published today in the January issue of Environmental Health Perspectives.

The findings confirm earlier studies showing that tobacco exposure hurts children's intellectual development. This study is even more persuasive because of its size and the fact that researchers did not rely on parents to recall how much they smoked, says Michael Shannon, chairman of American Academy of Pediatrics' Committee on Environmental Health.

In the study of nearly 4,400 youngsters, researchers found that kids subjected to the least amount of smoke scored an average of 7 points higher in standardized math and reading tests, compared with children exposed to high levels. Children with the lowest exposure also fared better on two kinds of widely used reasoning tests.

About 33 million children are at risk for reading problems caused by ''environmental tobacco,'' says Kimberly Yolton, study author and a researcher at Cincinnati Children's Hospital Medical Center.

She measured exposure to secondhand smoke by testing for cotinine, a byproduct of nicotine in the blood. Secondhand smoke contains 200 poisons, including 69 that cause cancer, the American Lung Association says.

Learning gaps were significant, researchers say, even after they considered other factors, such as race, income and parents' educational levels, that might have influenced test scores.

''Most smokers know that smoking is bad for them, but do they really know that smoking is bad for their children?'' Yolton asks.

These findings give cities and states another reason to ban tobacco in public places and for insurers to pay for programs that help smokers quit, Shannon says.

Tobacco is about as harmful to children's brains as lead, and fetuses exposed to tobacco in the womb are more likely to be born small or suffer other problems, Shannon says.