- Mainstream smoke which is directly inhales through the mouth end of the cigarette
- Side stream smoke which comes from the burning tip of the cigarette
Secondhand smoke is made up mainly of side stream smoke which is about four times more toxic than mainstream smoke. This is because side stream smoke contains much higher levels of many of the poisons and cancer-causing chemicals in cigarettes.
Scientific evidence shows that there is no safe level of exposure to secondhand tobacco smoke.
Secondhand smoke causes lung cancer and heart disease among adult non-smokers and a number of serious illnesses in adults and children can be attributed to secondhand smoke.
We hold six-week programmes around Wales which can help you to stop smoking. Call our free helpline on 0800 085 2219 to speak to one of our friendly team members and find out about your nearest session.
- ASH Factsheet - Secondhand Smoke in the Home (External document) 14/10/2011
- Secondhand smoke: What is it and what can you do about it? (External document) 13/10/2011
- P is for protecting babies and children from secondhand smoke (External document) 13/10/2011