New York: Exposure to second-hand parental smoke at home may not just affect an infant's respiratory system, but its heart as well, according to a new study.

The study, whose findings were presented at the American Heart Association's annual conference Thursday, was based on a survey of 128 children, 2 to 5 years old, and adolescents 9 to 14. The first lot absorbed six times more nicotine than the older children.

That exposure resulted in a dramatic increase of markers of inflammation and vascular injury signalling damage to the inner lining of the heart.

"This is the first study that looks at the response of a young child's cardiovascular system to second-hand smoke," said Judith Groner, co-author of the study.

The study found that toddlers in the homes of smokers not only had higher levels of nicotine, but also had higher levels of markers for cardiovascular disease in the blood.

"The dose of smoke is greater in toddlers than adolescents who are able to move in and out of the home," said John Bauer, senior author of the study.

"Toddlers are like a fish in a fishbowl. They are exposed at a higher dose. And it appears that toddlers also are more susceptible to the cardiovascular effects of smoke." IANS