Secondhand Smoke Exposure

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From 2017 to 2018, 25.8% of persons aged 3 years and older were currently exposed to second-hand smoke.

Summary graph for Secondhand Smoke Exposure, Click to see detailed view of graph

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Background

Secondhand smoke (SHS) is a mixture of the side stream smoke released by a smoldering cigarette, pipe, hookah/waterpipe, or cigar, and the mainstream smoke exhaled by a smoker. SHS is a complex mixture containing thousands of chemicals, including formaldehyde, cyanide, carbon monoxide, ammonia, and nicotine. More than 250 of the chemicals in SHS are known to be harmful, and at least 69 are known to cause cancer.

Conclusive scientific evidence documents that SHS causes premature death and disease in children and adults who do not smoke. Among adults, exposure to SHS has immediate adverse effects on the cardiovascular system, and long-term exposure to SHS causes coronary heart disease and lung cancer. Children exposed to SHS are at increased risk for sudden infant death syndrome, acute respiratory infections, middle ear disease, more severe asthma, respiratory symptoms, and slowed lung growth. 

There is no risk-free level of exposure to SHS, and only eliminating smoking in indoor spaces fully protects nonsmokers from exposure to SHS. Exposure to SHS among nonsmokers can be assessed by measurement of cotinine, a metabolite of nicotine. While cotinine levels may vary by individual due to the speed of nicotine metabolism and cotinine clearance, detection of cotinine above a minimum threshold is a validated measure of exposure to SHS in nonsmokers.

Measure

The percentage of nonsmokers exposed to secondhand smoke. (The percentage of nonsmokers aged 3 years and older with a serum cotinine level greater than 0.05 ng/mL and less than or equal to 10 ng/mL.)

Healthy People 2030 Target

  • Reduce the proportion of people who do not smoke but are exposed to secondhand smoke to 17.3%.

Healthy People 2030 is a set of goals set forth by the Department of Health and Human Services.
Note: Goals are indicated as blue line on Detailed Trend Graphs.

Data Source

Centers for Disease Control and Prevention, National Center for Health Statistics, National Health and Nutrition Examination Survey. “Secondhand smoke exposure” measure.

Trends and Most Recent EstimatesHelp with navigating the graphs and data tables

By Sex

Percentage of nonsmokers aged 3 years and older¹ exposed to secondhand smoke² by sex, 1988-2018
Overview Graph Detailed Trend Graphs Most Recent Estimates (2017 to 2018)
Percent of nonsmokers 95% Confidence Interval
Thumbnail of graph for Percentage of nonsmokers aged 3 years and older¹ exposed to secondhand smoke² by sex, 1988-2018 Both SexesClick to see the detailed trend graph for Both Sexes 25.8 22.8 - 28.7
MaleClick to see the detailed trend graph for Male 27.1 22.6 - 31.6
FemaleClick to see the detailed trend graph for Female 24.6 22.1 - 27.1
¹The 1988-1994 estimate starts at age 4 instead of age 3.
²As measured by a serum cotinine level of greater than 0.05 ng/ml and less than or equal to 10 ng/ml.

By Race/Ethnicity

Percentage of nonsmokers aged 3 years and older¹ exposed to secondhand smoke² by race/ethnicity, 1988-2018
Overview Graph Detailed Trend Graphs Most Recent Estimates (2017 to 2018)
Percent of nonsmokers 95% Confidence Interval
Thumbnail of graph for Percentage of nonsmokers aged 3 years and older¹ exposed to secondhand smoke² by race/ethnicity, 1988-2018 All RacesClick to see the detailed trend graph for All Races 25.8 22.8 - 28.7
Non-Hispanic WhiteClick to see the detailed trend graph for Non-Hispanic White 24.5 20.9 - 28.2
Non-Hispanic BlackClick to see the detailed trend graph for Non-Hispanic Black 47.8 41.5 - 54.0
HispanicClick to see the detailed trend graph for Hispanic 18.7 15.4 - 21.9
¹The 1988-1994 estimate starts at age 4 instead of age 3.
²As measured by a serum cotinine level of greater than 0.05 ng/ml and less than or equal to 10 ng/ml.

By Age

Percentage of nonsmokers aged 3 years and older¹ exposed to secondhand smoke² by age, 1988-2018
Overview Graph Detailed Trend Graphs Most Recent Estimates (2017 to 2018)
Percent of nonsmokers 95% Confidence Interval
Thumbnail of graph for Percentage of nonsmokers aged 3 years and older¹ exposed to secondhand smoke² by age, 1988-2018 Ages 3-11Click to see the detailed trend graph for Ages 3-11 38.2 34.4 - 42.0
Ages 12-17Click to see the detailed trend graph for Ages 12-17 32.9 26.9 - 38.9
Ages 18-29Click to see the detailed trend graph for Ages 18-29 33.9 28.1 - 39.8
Ages 30+Click to see the detailed trend graph for Ages 30+ 19.6 16.5 - 22.8
¹The 1988-1994 estimate starts at age 4 instead of age 3.
²As measured by a serum cotinine level of greater than 0.05 ng/ml and less than or equal to 10 ng/ml.

By Poverty Income Level

Percentage of nonsmokers aged 3 years and older¹ exposed to secondhand smoke² by poverty income level, 1988-2018
Overview Graph Detailed Trend Graphs Most Recent Estimates (2017 to 2018)
Percent of nonsmokers 95% Confidence Interval
Thumbnail of graph for Percentage of nonsmokers aged 3 years and older¹ exposed to secondhand smoke² by poverty income level, 1988-2018 <200% of federal poverty levelClick to see the detailed trend graph for <200% of federal poverty level 37.5 33.4 - 41.6
>=200% of federal poverty levelClick to see the detailed trend graph for >=200% of federal poverty level 19.0 15.7 - 22.3
¹As measured by a serum cotinine level of greater than 0.05 ng/ml and less than or equal to 10 ng/ml.

By Education Level

Percentage of nonsmokers aged 25 years and older exposed to secondhand smoke¹ by highest level of education obtained, 1988-2018
Overview Graph Detailed Trend Graphs Most Recent Estimates (2017 to 2018)
Percent of nonsmokers 95% Confidence Interval
Thumbnail of graph for Percentage of nonsmokers aged 25 years and older exposed to secondhand smoke¹ by highest level of education obtained, 1988-2018 Less than High SchoolClick to see the detailed trend graph for Less than High School 25.3 20.4 - 30.1
High SchoolClick to see the detailed trend graph for High School 27.5 22.4 - 32.5
Greater than High SchoolClick to see the detailed trend graph for Greater than High School 17.9 14.6 - 21.2
¹As measured by a serum cotinine level of greater than 0.05 ng/ml and less than or equal to 10 ng/ml.

Evidence-based Resources

The Cancer Control P.L.A.N.E.T. web portal contains tobacco control resources that support collaboration, identify evidence-based approaches, and list Evidence-Based Cancer Control Programs.

Additional Information on Secondhand Smoke Exposure

Year Range

1988-2018

Recent Summary Trend Year Range

2013-2018

Summary Tables

Secondhand Smoke

Recent Summary Trend

Falling

Desired Direction

Falling