Reference summary — not medical advice or a personal risk estimate.
Secondhand tobacco smoke
Group 1 — carcinogenic to humansAir & EnvironmentchemicalEvidence: sufficient_in_humans
Summary
Breathing other people's tobacco smoke is associated with lung cancer, even for nonsmokers.
Detail
Secondhand smoke is Group 1 with sufficient evidence for lung cancer. WHO, IARC and major national cancer bodies agree there is no safe level of exposure. Smoke-free home and workplace policies are the most effective protection.
Regional relevance
global
global
Documented in these products
Presence in a product category doesn't imply the product causes cancer. Click each to see the source and context.
Sources
Primary sources
Supporting sources
- Canadian Cancer Society — Canadian Cancer Society — Reduce your risk
- ACS — ACS — Known and Probable Human Carcinogens
- Cancer Research UK — Cancer Research UK — Causes of cancer and reducing your risk
- IARC / WHO — European Code Against Cancer — European Code Against Cancer (5th edition) — 14 ways you can help prevent cancer
- NTP — NTP — Report on Carcinogens (US National Toxicology Program)
- Cancer Council Australia — Cancer Council Australia — Causes of cancer
Consumer references
Third-party tools some readers use alongside primary evidence. Meyron doesn't endorse them; we link them because you'll otherwise hit them anyway.
- California Prop 65 list
State of California's list of chemicals known to cause cancer or reproductive harm.