Exposure to second-hand smoke occurs when non-smokers inhale other people's tobacco smoke. Second-hand smoke may also be called environmental tobacco smoke (ETS), passive smoking or involuntary smoking.
Types of second-hand smoke
Second-hand smoke is a combination of poisonous gases, liquids and particles that are harmful to health. Second-hand smoke consists of:
- mainstream smoke – the smoke exhaled by a smoker
- sidestream smoke – the smoke given off from a burning cigarette, cigar or pipe
Many of the harmful products in smoke are in gas form. Therefore, second-hand smoke cannot be entirely filtered out through ventilation systems or special fans. It can take many hours for the smoke of one cigarette to completely disappear.
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Chemicals in second-hand smoke
Second-hand smoke releases the same 4000 chemicals as smoke that is actively inhaled and over 70 of these can cause cancer. Second-hand smoke lingers in the air for non-smokers to breathe. Non-smokers exposed to second-hand smoke absorb the same harmful compounds as smokers do. However, the amount of exposure may be less because the chemicals may be thinned with room air.
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No amount of exposure to second-hand smoke is safe. Studies have shown that even low levels of second-hand smoke exposure can be harmful. An international panel of experts brought together by the International Agency for Research on Cancer (an agency of the World Health Organization) determined that second-hand smoke causes cancer and is a known carcinogen.
Second-hand smoke causes diseases and death in non-smokers.
- Second-hand smoke causes sore eyes and throat, nasal irritation, headaches, coughing and wheezing, nausea and dizziness.
- People exposed to second-hand smoke are more likely to get colds.
- Breathing in second-hand smoke can trigger asthma attacks and increase the chances of getting chest infections like bronchitis and pneumonia.
- People exposed to second-hand smoke for a long time are more likely to develop and die from heart problems, breathing problems and lung cancer.
- Each year, about 1000 non-smoking Canadians die from second-hand smoke.
- Second-hand smoke is a main risk factor for lung cancer among non-smokers. In Canada each year, over 300 deaths from lung cancer occur in non-smokers.
- There is some evidence that second-hand smoke is associated with cancers of the larynx and pharynx.
- About 700 Canadian non-smokers die each year due to coronary heart disease because of exposure to second-hand smoke.
- Exposure to second-hand smoke is a cause of sudden infant death syndrome (SIDS).
- Some studies have found that exposure to second-hand smoke may be linked to cancer of the larynx and pharynx.
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People at risk
Children, pregnant women, older people and people with heart or breathing problems should be especially careful to avoid second-hand smoke.
Children are more at risk of getting sick than adults when they breathe in second-hand smoke. Their bodies are still growing and children breathe faster than adults, so they absorb more harmful chemicals. Children’s immune systems, which protect them from getting sick, are less developed and cannot protect them as well from tobacco smoke.
Even pets can be affected by second-hand smoke. Cats, dogs and other animals who regularly breathe in second-hand smoke are more likely to develop cancer and other health problems. Because smoke particles can cling to their fur, they may also ingest smoke particles when grooming themselves with their tongues.
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Third-hand smoke is a new word for the smoke that gets trapped in hair, skin, fabric (including clothing, curtains and car seats), carpet, furniture and toys. Each time someone smokes, smoke gets trapped in or on the fabric, furniture, walls and other objects around them. Third-hand smoke contains the same toxic chemicals as second-hand smoke. These chemicals stick around long after a smoker has put out a cigarette, cigar or pipe, and it builds up over time. The chemicals from the trapped smoke pollute the air and get into a person's lungs and body.
Third-hand smoke can also get into household dust. Infants and children can swallow this when they put their hands in their mouths. Infants take in more third-hand smoke chemicals because they breathe more quickly than adults and they usually spend more time crawling or playing on the floor.
There is no research about the health effects of exposure to cigarette smoke through these items, but it is assumed it would be small compared to direct second-hand smoke exposure when living with a smoker.
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Reducing your risk
Even after a cigarette is out, second-hand smoke remains on clothes and many other surfaces, and can still be toxic to people and pets. Opening a window or turning on a fan is not enough to clear the air.
Take steps to avoid second-hand smoke, including making your home and car smoke-free.
In the home
Because Canadians spend most of their time indoors, air quality in the home is important.
- Live smoke-free. If you smoke, get help to quit. If you live with smokers, be supportive of their efforts to quit. However, be firm about your right to a smoke-free home, especially if you are pregnant or have children.
- Think about how to make your home smoke-free. Talk about it with family and friends.
- Politely ask family members and friends to smoke outside. Let them know you are rejecting their smoking, not them.
- Set up a comfortable area, preferably outdoors, for smokers to use. Remove all ashtrays from inside the home.
In apartments or condominiums
Smoke can enter an apartment or condominium unit through vents and openings in multi-unit buildings where the ventilation system is shared. Second-hand smoke can also drift under doors and through cracks and air leaks around electrical outlets, plumbing and windows.
- Install special seals for electrical outlets to prevent smoke from entering. These seals are available at hardware stores.
- Install door sweeps to prevent smoke from entering your unit.
- Seal cracks around vents and windows with foam insulation.
- Talk to your neighbours. Work together to reduce second-hand smoke.
- Read your rental agreement. If all or part of your building is smoke-free, ask the landlord to enforce the rules.
- Talk to your landlord or condo association about making your floor or building smoke-free. If all else fails, consider moving to a smoke-free building.
In the car
Second-hand smoke is even more dangerous inside the small air space of a car because the smoke is more concentrated. The chemicals remain in the car, even when the tobacco is no longer burning.
- Let all passengers know that your car is smoke-free.
- Give the car a good cleaning. Vacuum the upholstery.
- Clean out the ashtray. Fill it with change or gum.
- Instead of smoking in the car, try to leave work or home a few minutes earlier than usual so you have time to smoke outside before getting into the car.
Away from home
- Avoid places where children will be exposed to second-hand smoke.
- Talk to your employer about ways of making a workplace smoke-free, if it isn't already.
- When travelling, ask for smoke-free rooms.
- Support businesses that are smoke-free.
- Support local bylaws and campaigns that restrict smoking.
- Find out how you can help in the fight against tobacco.
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