Study backs up warnings over second hand smoke

By Ed Stoddard

DALLAS (Reuters) - Even small amounts of secondhand tobacco smoke can damage a child's arteries, researchers reported on Monday, adding to the growing body of evidence on the harmful affects of exposure to smoking.

The Finnish study published in the American Heart Association journal Circulation looked at the affect of smoking on children between the ages of 8 and 11.

"Our study shows that exposure to second-hand smoke can harm the function of the arteries in children," said Katariina Kallio, of the Research Centre of Applied and Preventive Cardiovascular Medicine at the University of Turku in Finland, who led the study.

"Even a little exposure to smoke at home or in the public environment can be harmful to the cardiovascular system of healthy schoolchildren," Kallio said.

Instead of relying on parents to report whether and how much they smoked at home, the researchers measured the blood of the children for a substance called cotinine, which the body produces as it breaks down the nicotine in tobacco smoke.

Cotinine levels were measured annually in about 400 tested children between the ages of 8 and 11.

When they reached 11 the children got high-resolution ultrasound tests of the brachial artery in the arm to assess how well the lining of the blood vessels work.

The children were divided into three groups based on their cotinine concentrations: 229 children in the non-detectable cotinine group; 134 children in the low-cotinine group; 39 children in the high-cotinine group.