A study conducted at the New York City Health Department suggests more than half of all non-smokers in there show evidence of cigarette chemicals in their blood.
The results come after nearly 2000 adults underwent blood tests and filled out surveys about their smoking habits. Researchers found 57% of non-smoking New York City residents had cotinine in their blood, a by-product of nicotine. Researchers gathered their data a year after New York City passed a strict ban on public smoking, which prohibits people from lighting up in workplaces, including restaurants and bars.
Living in apartment buildings with smoking neighbors and passing smokers on crowded city sidewalks appear to be the main sources of secondhand smoke exposure in New York City. Nationwide, experts estimate 45% of adult non-smokers have traces of cotinine in their blood.