Sociodemographic Differences Among U.S. Children and Adults Exposed to Secondhand Smoke at Home: National Health Interview Surveys 2000 and 2010

Objective

We examined the levels and change in prevalence of self-reported secondhand smoke (SHS) exposure at home, and analyzed sociodemographic differences in exposure among children (aged 0–17 years) and nonsmoking adults (aged ≥18 years) in the United States in 2000 and 2010.

Methods

We included 18,731 children and 44,049 adults from the 2000 and 2010 National Health Interview Survey Cancer Control Supplements. We used multivariate logistic regression to determine the factors associated with exposure.

Results

The prevalence of self-reported SHS exposure declined from 2,627 of 10,636 (24.7%) to 663 of 8,095 (8.2%) for children and from 2,863 of 23,665 (12.1%) to 897 of 20,384 (4.4%) for adults from 2000 to 2010. SHS exposure declined for all population subgroups between the two years, but differences were found. Compared with 2000, children aged 12–17 years in 2010 were no longer more likely than children aged 0–5 years to be exposed to SHS. Non-Hispanic black children and adults were more likely than non-Hispanic white children and adults to be exposed to SHS in 2010. In 2010, no differences were found for children whose parents had a higher level of education, and no differences were observed for children or adults with high family income vs. other levels of family income. Children living in the Midwest and South had higher levels of SHS exposure than children in other regions in 2010.

Conclusions

Self-reported SHS exposure at home declined for all population subgroups from 2000 to 2010, but socioeconomic differences existed for some subgroups in both years. Current tobacco control policies need to be improved to reach all population subgroups so that SHS exposure can be further reduced, especially among vulnerable populations.Secondhand smoke (SHS) exposure has been linked to numerous health conditions, including respiratory illness, cancer, and heart disease for adults;^1,2 and middle ear disease, asthma, respiratory symptoms, abnormal pulmonary function, and attention deficit hyperactivity disorder (ADHD) for children.^3,4 The health effects of SHS exposure also result in excess economic costs. One study estimated the total annual SHS-attributable medical cost in the United States at $6.9 billion in 2005.⁵ Another study reported that SHS exposure resulted in more than 42,000 deaths, nearly 600,000 years of potential life lost, and $6.6 billion of lost productivity in 2006 in the United States.⁶SHS exposure occurs in three main settings: at home, in the workplace, and in public places. The home setting is the primary source of SHS exposure for children and a major source of exposure for nonsmoking adults.³ The prevalence of SHS exposure in the United States has been declining in recent years.^3,7 Using data from the National Health and Nutrition Examination Surveys (NHANES), a recent Centers for Disease Control and Prevention (CDC) report found that the percentage of the U.S. nonsmoking population (aged ≥3 years) with cotinine-measured SHS exposure declined from 52.5% in 1999–2000 to 25.3% in 2011–2012.⁷ Previous studies have also reported socioeconomic differences in SHS exposure for both adults and children. A study using 1999–2010 NHANES data found that never-smoking adults (aged ≥20 years) in the lowest socioeconomic quintile were two to three times more likely than those in the highest quintile to be exposed to SHS at home.⁸ Another study that used the 2007 National Survey of Children''s Health in the United States found that, compared with children from higher socioeconomic backgrounds, children from lower socioeconomic backgrounds had higher odds of self-reported SHS exposure at home; and that non-Hispanic white, non-Hispanic black, American Indian, and mixed-race children had higher odds of SHS exposure at home than Hispanic children.⁹ CDC''s most recent report also found that cotinine-measured SHS exposure was highest among children aged 3–11 years, non-Hispanic black people, those living below the federal poverty threshold, and people living in rental housing during 2011–2012.⁷Many smoke-free policies were implemented from 2000 to 2010,¹⁰ which contributed to a decline in SHS exposure in the United States.⁷ To examine whether or not all population groups benefited from these policies, we examined the change in prevalence of self-reported SHS exposure at home for children and nonsmoking adults in the United States from 2000 to 2010, assessed the sociodemographic factors associated with SHS exposure, and compared the significant factors in the two years.