Decades-long declines in secondhand smoke exposures in the U.S. have stalled in recent years, with young children, nonsmoking blacks and nonsmokers living in poverty having some of the highest exposures, the CDC said.
An estimated 58 million American's, or about 25% of nonsmokers, were exposed to secondhand smoke from cigarettes or other burning tobacco products in 2013-2014, according to data from the National Health and Nutrition Examination Survey (NHANES) and .
That represented no significant change in secondhand smoke exposures from the 2011-2012 NHANES iteration. Secondhand smoke exposures had declined substantially from 1988, when it stood at 87.5% of nonsmokers.
Exposure prevalence was particularly high among nonsmoking non-Hispanic blacks (50.3%), people living in poverty (50.3%), those living in rental housing (38.6%) and young children (37.9%).
As expected, the highest exposures were reported among nonsmokers who lived with someone who smoked inside the home (73%).
"We know there's no safe level of secondhand smoke exposure," CDC Director Robert R. Redfield, MD, said in a written press statement. "These findings reveal that there is still much more to do to protect everyone -- especially children -- from this completely preventable health hazard."
Secondhand smoke exposure was determined through assessment of serum cotinine levels, which was a component of the in-person NHANES survey method.
CDC researchers concluded that the stalled declines in secondhand smoke exposure may be attributable to the slow adoption of statewide comprehensive smoke-free laws during the 2013-2014 NHANES reporting period.
Twenty-seven states and the District of Columbia have comprehensive smoke-free laws. About 200 communities adopted their own from 2015 to 2017, the report noted.
A nationwide ban on smoking in public housing also went into effect this summer.
Despite this progress, the report highlighted key persistent disparities in secondhand smoke exposures, including:
- Half of black nonsmokers are exposed to secondhand smoke, including two out of every three black children
- More than three in 10 nonsmokers with less than a high school education are exposed to secondhand smoke
- The prevalence of secondhand smoke exposure among young children (3-11 years old) was 37.9%, which was significantly higher than among adult who were age 20 and older (22%)
The CDC report called for continued efforts to implement comprehensive smoke-free laws in workplaces and public places, adoption of smoke-free home and vehicle rules, and educational interventions warning about the risks of secondhand smoke exposure.
"We know what works to reduce secondhand smoke exposure," said Corinne Graffunder, DrPH, who directs the CDC's Office on Smoking and Health. "Smoke-free environments are the best way to fully protect all people from the dangers of secondhand smoke in the places they live, work and gather."
Primary Source
MMWR
Tsai J, et al. "Exposure to secondhand smoke among nonsmokers - United States, 1888-2014" MMWR 2018, Dec. 7.