Explain the health dangers of secondhand tobacco smoke and how to measure its exposure

Answer 1

Children and adults exposed to secondhand tobacco smoke are at increased risk for illness and chronic disease. In the early 1990s, the Environmental Protection Agency declared secondhand smoke to be a class A carcinogen. There was apparent rapid progress in the proportion of self-reported nonsmokers indicating that they were not exposed across the United States. In the decade to 2010, in-person reports of exposure to secondhand smoke among children under age 6 years decreased rapidly from 27% to 8%, while reported exposure among nonsmokers dropped by half from 84% to 41%. However, there are concerns about the validity of this self-reported measure of exposure. Fortunately, new measures of blood concentrations of key nicotine metabolites are available-and inhalation of nicotine is confined mainly to cigarette smoke. Accordingly, this measure has become the gold standard for measuring secondhand smoke exposure. Exposure is indicated by the proportion with a blood nicotinine level above the accepted detection limit (0.05ng/ml) but below 10ng/ml (cut-point for defining smoking). Between 2005 and 2008, 52% of 3- to 11-year-olds measured in the National Health and Nutrition Examination Survey (NHANES) were categorized as exposed to secondhand smoke. The 2020 objective is to reduce this exposure level by 10%.?