Healthy Homes

Second Hand Smoke

 Surgeon General’s Inforgraphics on Second Hand SmokeSecond Hand Smoke 

Second hand smoke occurs when someone uses and exhales tobacco products such as cigarettes, cigars, or pipes, and the smoke is then inhaled involuntarily by others.

Health Effects

  • Tobacco smoke contains more than 7,000 chemicals, including hundreds that are toxic and about 70 that can cause cancer.
  • Since 1964 it is estimated that 2.5 million deaths are attributed in the U.S. to health problems caused by exposure to secondhand smoke.
  • Globally, more than a third of all people are regularly exposed to the harmful effects of smoke.
  • Separating smokers and nonsmokers within the same air space may reduce, but does not eliminate, exposure of nonsmokers to tobacco smoke. 
  • Tobacco residue remains in the area even after the smoker has left the area. This residue is referred to as third hand smoke or residual smoke and also poses health risks to those who are exposed.
  • In the U.S., secondhand smoke causes approximately 3,000 lung cancer deaths annually among nonsmokers. 
  • Secondhand smoke exposure increases the risk for lung cancer by 30 percent in nonsmokers.

Seniors and Children Are Especially Susceptible

  • In the U.S., secondhand smoke exposure causes an estimated 150,000 - 300,000 annual cases of bronchitis and pneumonia.
  • Exposure risk of sudden infant death syndrome (SIDS) is 2.5 times greater for infants exposed to secondhand smoke. 
  • Second hand smoke is responsible for 40-60% of asthma cases for children between two months and two years of age.
    For children with established asthma, second hand smoke causes additional episodes and increases its severity.

Do You Smell Smoke?

Used by permission ©(2016) American Lung Association.

What Environmental Health Professionals are Doing

Environmental Health professionals conduct a variety of activities to control tobacco exposure, such as:

  • Investigate - Complaints and sample environments that may have unhealthy levels.
  • Enforce - Many municipalities across the county prohibit smoking in public places, so EH professionals enforce local codes, ordinances, and statutes restricting tobacco use. While there are not well-established exposure limits for tobacco smoke, there are many exposure limits for specific chemicals within tobacco smoke. Some of these chemicals have exposure limits for occupational settings.
  • Educate - Environmental Health agencies provide many educational resources and programs in awareness and tobacco cessation. They spearhead health campaigns to prevent illness and injury. Read about what local environmental health agencies are doing for their communities. 

Emerging Issues

NEHA Resources

World Environmental Health Day - Celebrate with NEHA on September 26, 2016. This year's theme is tobacco control and NEHA is focusing specifically on the negative health effects of second and third hand smoke to both individuals and societies. Help us raise awareness of the environmental health implications of tobacco use. 

World Environmental Health Day Graphics with Infant and Puppy

Learn More about Third-Hand Smoke and Tobacco and Environmental Health.

Additional Resources

Secondhand smoke infographic on group exposureCDC Vital Signs 


Third Hand Smoke

The Hidden Hazard of Third Hand Smoke

Tobacco use causes 20% of cancer deaths worldwide, and it is estimated that tobacco-related deaths will result in 10-million deaths annually by 2020. We've come a long way since the mid-1900's in understanding the negative health effects of tobacco to smokers.

More recently, we've learned that second hand smoke also has deleterious consequences for those who are exposed to it. Yet, the concept of third hand smoke goes largely unnoticed even though a study in 1953 first identified the problem.

What is third hand smoke?

  • Third hand smoke is nicotine residue that remains on surfaces including walls, doors, drapery, carpets, clothes, furniture, flooring material, and acoustic tiles in ceilings. This pollutant also can be inhaled when it is re-emitted through dust in the air, and it can react with substances in the environment to create secondary pollutants on surfaces.
  • People, especially seniors and children, and pets are affected by this under-appreciated health hazard through skin exposure, dust inhalation and ingestion.
  • Some chemicals* found in third hand smoke are:
    -hydrogen cyanide (used in chemical weapons)
    -butane (used in lighter fluid)
    -toluene (found in paint thinners)
    -carbon monoxide
    -polonium-210, a highly radioactive carcinogen
  • Research demonstrates that tobacco smoke is a toxic substance with no safe level of exposure, and that the risks from exposure are largely dose related.

*Visit the CDC’s Agency for Toxic Substances and Disease Registry for information on health risks associated with these chemicals. 

Father smoking cigarette with baby in home, second and third hand smoke effects

Who is affected by third hand smoke?

  • Third hand smoke affects people who live in homes, hotels, or any indoor environment that was used long term by smokers. Even cars used by smokers can have third hand smoke residue.
  • Babies, toddlers, and children are at greater risk of negative health effects because:

1) they inhale 40 times more than adults

2) they have greater hand/object/mouth contact so they absorb proportionately more through ingestion

3) have greater absorption through their skin

  • Data show that individuals classified as low socio-economic status tend to live in more multi-unit housing where smoking may not be banned.
    If your neighbor smokes, it can get into your apartment through the ventilation system.
    Third hand smoke can be present in apartments even if they have been vacant for two months and are cleaned and prepared for new residents.

How can Environmental Health professionals help?

Third hand smoke is part of an individual’s built environment, which often they have little control over. Environmental health professionals seek to protect people against environmental factors that may adversely impact human health; they are instrumental in enforcing regulations and providing health education to limit third hand smoke exposure and associated disease outcomes.

Learn more about Tobacco and EH Professionals

Why have I never heard about third hand smoke before?

It took decades to develop the proponderance of evidence and prove that smoking causes lung cancer and a multitude of other adverse health effects. It took additional years to prove second hand smoke also kills.
It was only recently that scientists identified third hand smoke from tobacco combustion lingering on clothing, bedding, carpeting and furniture and attributed their contribution to adverse health effects.


What can be done to limit exposure of third hand smoke?

A 2010 study indicated that third-hand smoke accumulates in smokers' homes and persists even after homes have been vacant for two months and are cleaned and prepared for new residents.
This study also indicates that there is not much that can be done in terms of cleaning third hand smoke in affected places. Recommendations to minimize potential negative health effects are:

  • Avoid any indoor environment that was used long-term by smokers.
  • Insist that smokers go outdoors and do not smoke in homes or in cars.
  • Support smoking bans and enforcement of them.
  • In homes with long term smoke exposure consider replacing carpets, ventilation systems, furniture, etc.

While research needs to be done on how to clean up third hand smoke, it is best to simply avoid any indoor environment that was used long-term by smokers.

statewide smoke free laws for United States MapSmoke Free Places in the U.S.

To find local ordinances, maps, and resources for smoke-free venues, visit

Many of the following indoor places in the U.S. have become smoke free:

  • Hospitals
  • Nursing Homes
  • Colleges and Universities
  • Correctional facilities
  • Hotels/motels
  • Airports
  • Major League Baseball, National Football League stadiums
  • Multi-Unit housing
  • Casinos and Gambling Facilities
  • Pharmacies (CVS)
  • Bars and restaurants
  • Workplaces


Many outdoor areas are becoming smoke free in the U.S. as well, such as:

  • Beaches
  • Public Transit spaces
  • Parks and zoos
  • Outdoor patios

Maps at


World Environmental Health Day

World Environmental Health Day on September 26, 2016 GraphicTobacco and Environmental Health Implications

Tobacco use causes 20% of cancer deaths worldwide, and it is estimated that tobacco-related deaths will result in 10-million deaths annually by 2020. We've come a long way since the mid-1900's in understanding the negative health effects of tobacco.  

NEHA celebrated World Environmental Health Day on September 26, along with the International Federation of Environmental Health (IFEH) and many other organizations to shed light on the important work of environmental health around the world. This year's theme is tobacco control and NEHA is focusing specifically on the negative health effects of second and third hand smoke to individuals and societies.
We invite you to raise awareness of World EH Day and the environmental health implications of the growth, sale, and use of tobacco products.

Learn More Tobacco and Environmental Health Implications

World EH Day Toolkit

Check out our toolkit for World EH Day resources you can use to help spread the word to others.


Thank You to Our World EH Day Partners

American Academy of Sanitarians
American Lung Association
American Public Health Association
Association of Food and Drug Officials
Association of Public Health Laboratories
Association of State and Territorial Health Officials
Children’s Environmental Health Network
Child Care Aware
Colorado Department of Public Health and Environment
Colorado State University
Council of State and Territorial Epidemiologists
Environment Colorado
Green & Healthy Homes Initiative
International Federation of Environmental Health
National Association of City and County Health Officials
National Center for Environmental Health Strategies
National Institute of Environmental Health Sciences
U.S. Centers for Disease Control and Prevention
U.S. Environmental Protection Agency
U.S. Food and Drug Administration
U.S. Housing and Urban Development