Dangers of second-hand smoke
Second-hand smoke creates serious health risks for you and your family. Avoid these risks by keeping your home and car smoke-free.
On this page
What is second-hand smoke?
Second-hand smoke comes from burning tobacco products and from exhaled tobacco smoke.
Most of the smoke from a lit cigarette is not inhaled by the smoker. It fills the air around the smoker. This endangers everyone in the area.
Tobacco smoke contains harmful chemicals, some of which are cancer-causing. The level of some of these chemicals can be higher in second-hand smoke than in the smoke inhaled directly by the smoker.
What are the health risks of second-hand smoke?
Second-hand smoke hurts everyone. It contains the same chemicals that are inhaled by a smoker (including nicotine). Out of the over 4,000 chemicals, at least 70 can cause cancer. There is no safe level of exposure to tobacco smoke.
Groups that are at particular risk from second-hand smoke include:
- unborn babies, and
- infants and children.
Risks to unborn babies
If you are pregnant, avoid areas where others are smoking. Pregnant women who smoke or who are exposed to second-hand smoke are at a higher risk for problems with childbirth. Risks include:
- stillbirth, and
- premature birth.
Unborn babies are particularly vulnerable to second-hand smoke. Second-hand smoke chemicals can reach them through their mother's placenta.
Exposing unborn babies to second-hand smoke can increase their risk of low birth weight and slowed growth. It can also put them at risk of developing health problems during childhood, such as:
- lymphomas, or
- brain tumours.
If you are a smoker who is trying to get pregnant, you should quit immediately. If you are already pregnant, quitting now and staying smoke-free can still have important health benefits for you and your baby.
Risks to infants and children
Second-hand smoke is especially dangerous for babies and children. Their lungs are still developing and are not as strong as those of adults. Children also breathe more quickly than adults. This causes them to take in more chemicals from the air. Their immune systems can also be damaged by second-hand smoke toxins.
Increased health risks from second-hand smoke include:
- sudden infant death syndrome (SIDS),
- ear infection, or
- breathlessness and coughing.
Risks to adults
Even healthy, non-smoking adults are at risk for health problems if they breathe second-hand smoke. Second-hand smoke increases their risk of:
- heart problems,
- lung cancer,
- breathing problems (like asthma),
- excessive coughing, and
- nasal and chest infections.
Every year in Canada, second-hand smoke causes 800 deaths from lung cancer and heart disease in non-smokers.
If you are a smoker, avoid smoking around others, especially children, pregnant women and people with breathing problems.
Why is second-hand smoke particularly dangerous in enclosed spaces?
Smoking in enclosed spaces (like in your home or car) increases the risks linked with second-hand smoke exposure. This is because the level of second-hand smoke is higher in enclosed spaces.
Smoking in the home
Even when doors are closed, second-hand smoke can spread to other rooms in your home.
Second-hand smoke toxins also remain in a room long after someone has smoked. These harmful toxins can cling to different materials, such as:
- food, and
Opening windows does not reduce the dangers of second-hand smoke in the home. Using a fan, air freshener or air purifier cannot remove all cancer-causing chemicals and toxins in the air.
You can reduce your family's exposure to second-hand smoke by not allowing smoking indoors.
Smoking in the car
Smoking in your car is also dangerous. If someone smokes in your car, there is no way to avoid the dangers of second-hand smoke.
- Even with the windows down, second-hand smoke is dangerous.
- Air fresheners will not reduce the risk of second-hand smoke. They only hide the smell.
Second-hand smoke toxins can also stick to car surfaces. This means that smoking alone in a car can still be harmful to your family and friends.
How can I avoid second-hand smoke?
Avoiding second-hand smoke is important for your health and the health of your family. Keep second-hand smoke away from others by following these safety precautions:
If you smoke
- Quit smoking. If you are not ready to quit, only smoke in areas where others will not be exposed to your smoke.
- Make your home and car smoke-free. Avoiding indoor smoking can lower your own cigarette use and increase your chances of successfully quitting.
- When smoking outside a building, make sure you are several metres away from entrances, vents and windows.
- Use a designated container for cigarette ashes and filters (butts).
If you do not smoke
If you have children
Keep second-hand smoke away from the areas your children spend their time. Such areas include daycares, after-school programs and the cars of people giving your child a ride.
You have the right to be smoke-free
There are laws and regulations that protect your right to smoke-free air. Smoke-free legislation is in place at the federal, provincial, territorial and municipal levels to protect your health. This legislation restricts smoking in places such as:
- federal buildings,
- bars, casinos, restaurants and patios,
- planes, trains, public ferries and buses (including shelters),
- public beaches, and
- city-owned property (like parks and playgrounds).
Check with your provincial or territorial Ministry of Health as well as your municipal government to find out which policies are in effect where you live.
For more information, you can refer to the Non-smokers' Health Act. This Act regulates smoking in federal workplaces and other public places under federal jurisdiction.
- Date modified: