Secondhand smoke: Avoid dangers in the air

Exposure to the toxins in secondhand smoke can cause serious health problems. Know what you're breathing — and consider practical steps to protect your family.

By Mayo Clinic Staff

You don't smoke because you understand the dangers — but what about smoke you inhale involuntarily? Secondhand smoke causes and contributes to various health problems, including heart disease and lung cancer. And with adult smokers numbering about 1 billion worldwide, secondhand smoke exposure is virtually unavoidable for children and adults who don't smoke.

Understand what's in secondhand smoke, and consider ways to protect yourself and those you love from it.

What's in secondhand smoke?

Secondhand smoke includes the smoke that a smoker exhales (mainstream smoke) and the smoke that comes directly from the burning tobacco product (sidestream smoke).

Secondhand smoke contains toxic chemicals, including:

  • Ammonia, used in cleaning products
  • Benzene, found in gasoline
  • Cadmium, a toxic metal
  • Cyanide, used in chemical weapons
  • Formaldehyde, an industrial chemical

It isn't just the smoke that's a concern, though. The residue that clings to household dust and surfaces is called thirdhand smoke. Young children are particularly at risk for thirdhand smoke exposure due to their frequent contact with contaminated materials, such as carpeting.

How risky is secondhand smoke?

Secondhand smoke causes or contributes to serious health problems, including:

  • Cancer. Secondhand smoke is a known risk factor for lung cancer.
  • Heart disease. Exposure to secondhand smoke increases the risk of heart disease by about 25% to 30%.
  • Chronic lung disease. Exposure to secondhand smoke even for a short time causes measurable decreases in lung function. This can lead to chronic lung disease.

Secondhand smoke poses additional risks for children, who are especially vulnerable to the effects of secondhand smoke. Problems include:

  • Reduced birth weight. Exposure to secondhand smoke during pregnancy increases the risk of having a baby with a reduced birth weight.
  • Sudden infant death syndrome (SIDS). Secondhand smoke exposure is believed to increase the risk of SIDS.
  • Asthma and respiratory illness. Secondhand smoke exposure is linked with the increased risk — and severity — of childhood asthma and wheezing. Infants of parents who smoke are more likely to develop bronchitis and pneumonia during the first year of life.

How can secondhand smoke be avoided?

With planning, you can reduce your family's exposure to secondhand smoke. Start with these simple steps:

  • Don't allow smoking in your home. Opening windows and using fans and ventilation systems doesn't eliminate exposure to secondhand smoke.
  • Don't allow smoking in your vehicle, even with the windows down. If a passenger must smoke while you're traveling, stop as needed for smoke breaks outside the car.
  • Choose smoke-free care facilities. This applies to child care facilities as well as facilities for older adults.
  • Patronize businesses with no-smoking policies. Choose smoke-free restaurants. When you travel, request nonsmoking hotel rooms and rental cars.

If you have a partner or other loved one who smokes, offer support and encouragement to stop smoking. The entire family will benefit.

March 20, 2020 See more In-depth

See also

  1. 3 ways to get closer to achieving your goals
  2. Make healthy habits stick
  3. 5 do's and don'ts for staying motivated
  4. 3 ways to avoid secondhand smoke
  5. 7 signs and symptoms not to ignore
  6. Energy management
  7. Animal bites: Do you need a tetanus shot?
  8. Are you doing everything you can to stay healthy?
  9. Belching, intestinal gas, gas pains and bloating
  10. Bone health tips
  11. Can COVID-19 (coronavirus) spread through food, water, surfaces and pets?
  12. Cancer-prevention strategies
  13. Cellphones and cancer
  14. Colon cancer screening
  15. Coronavirus safety tips for going out
  16. Coronavirus: What is it and how can I protect myself?
  17. Coronavirus travel advice
  18. Plastic surgery
  19. Herd immunity and coronavirus
  20. COVID-19 and holidays
  21. Long-term effects of COVID-19
  22. COVID-19: How much protection do face masks offer?
  23. COVID-19 (coronavirus): Quarantine, self-isolation and social distancing
  24. Do adults need shots?
  25. Don't save leftover pain pills
  26. Exercise: Check with your doctor
  27. Find meaning in the small things
  28. Flu Shot Prevents Heart Attack
  29. Functional fitness training
  30. Overcome obstacles to your goals
  31. Healthy holiday habits: How to get back on track
  32. Hand drying
  33. Hand-washing tips
  34. Healthy habits that boost happiness
  35. Healthy heart for life: Avoiding heart disease
  36. Heart attack prevention: Should I avoid secondhand smoke?
  37. Home Health Hazards
  38. Brown fat
  39. How social support spurs you
  40. Break the busy cycle
  41. How to take your pulse
  42. How to safely go to your doctor during the COVID-19 pandemic
  43. How to take your temperature
  44. How well do you wash your hands?
  45. Injury Season for Snow Blowers
  46. Investing in yourself
  47. Is antibacterial soap a do or a don't?
  48. Keep the focus on your long-term vision
  49. Liposuction alternatives
  50. Lost in Space
  51. Making progress towards your goals
  52. Mammogram guidelines: What are they?
  53. Make over your mindset to make time for your health
  54. Mayo Clinic Minute: You're washing your hands all wrong
  55. Mayo Clinic Minute: How dirty are common surfaces?
  56. Measles vaccine: Can I get the measles if I've already been vaccinated?
  57. Medical family tree
  58. Infographic: Organ Donation Donate Life
  59. Infographic: Paired Donation Chain
  60. Infographic: Pancreas Kidney Transplant
  61. Personal health records
  62. Personalize your wellness journey
  63. Stick to healthy-eating goals at social gatherings
  64. Posture: Align yourself for good health
  65. Posture check: Do you stand up straight?
  66. New Year's resolutions
  67. Safe outdoor activities during the COVID-19 pandemic
  68. Creating a wellness vision
  69. Sitting risks: How harmful is too much sitting?
  70. Good posture tips
  71. Back exercises
  72. Proper lifting techniques
  73. Stay healthy during the COVID-19 (coronavirus) pandemic
  74. Stop multitasking and focus
  75. Telemedicine online doctor visits
  76. Thirdhand smoke: What are the dangers?
  77. Want good health? Build a solid base
  78. The benefits of gratitude
  79. Video: Travel safely for medical care during the COVID-19 pandemic
  80. Travel Safety
  81. Triclosan
  82. Using if-then statements
  83. Vaccines for adults
  84. Fight coronavirus transmission at home
  85. What are superbugs?
  86. What are superbugs and how can I protect myself from infection?
  87. Air purifiers and smoke