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.

"These ultrasound studies revealed a significantly lowered endothelial function, a measure of arterial health, in the group of children with the highest cotinine concentrations," the heart association said in a statement.

"If secondhand smoke can wreak havoc on the cardiovascular system of children as young as eleven, imagine what the effects will be on adults working 40 hours a week in a smoke-filled environment," said M. Cass Wheeler, Chief Executive Office of the American Heart Association.

"State lawmakers must heed the advice of scientific experts and pass smoke-free workplace laws to protect citizens from the deadly effects of secondhand smoke," Wheeler said.