Blood tests reveal tobacco smoke residues in non-smoking New Yorkers
More than half of non-smoking New Yorkers have elevated levels of cotinine in their blood - meaning that they were recently exposed to toxic second-hand smoke in concentrations high enough to leave residues in the body. Cotinine, a by-product of nicotine breakdown, is not harmful itself but signals exposure to environmental tobacco smoke. A Health Department study, published online this week in the journal Nicotine and Tobacco Research, shows that 57% of adult New Yorkers (2.5 million) have elevated cotinine levels, compared to 45% of adults nationwide - a finding that may reflect the city's dense, urban character. Second-hand smoke contains many harmful chemicals. It is known to cause cancer and heart disease in adults, as well as serious health problems for children.