Secondhand smoke exposure among nonsmoking adults : United States, 2015–2018

Secondhand smoke (SHS) exposure results when smoke from burning tobacco products is inhaled by nonsmokers (1,2). Acute respiratory effects, coronary heart disease, stroke, lung cancer, and premature death are associated with SHS exposure (2,3). There is no risk-free level of SHS exposure (1). The prevalence of SHS exposure declined by 71.2% from 1988 to 2014 (4). This report examines the prevalence of SHS exposure among nonsmoking U.S. adults in 2015-2018 based on blood levels of cotinine, a metabolite of nicotine. Trends in SHS exposure are also presented.