Add another danger to secondhand smoke exposure: Toddlers appear to absorb more nicotine in the home than their older siblings, and can show the markers of heart disease as early as 2 years of age, according to results of a study presented at the American Heart Association's 48th Annual Conference on Cardiovascular Disease Epidemiology and Prevention. Nicotine levels in the hair of 2- to 5-year-olds in smokers' homes were almost five times higher than those of 9- to 14-year-olds with parents who smoked with similar frequency. Also, exposed toddlers' blood tests revealed early endothelial damage, and the presence of soluble intracellular adhesion molecules, which can herald vascular inflammation and atherosclerosis. Researchers noted that toddlers are essentially trapped in the home—unlike adolescents, who can escape continuous smoke inhalation—and that further study of long-term effects of such early exposure is needed.

http://Eurekalert.org/. "Toddlers affected most by secondhand smoke exposure at home." 2008. http://www.eurekalert.org/pub_releases/2008-03/aha-tam031008.php (12 Mar. 2008).