Air Quality in the Home

Keeping your home free from hazards is important for good health. This is particularly true for children and people with allergies or a lung disease such as asthma, bronchitis or emphysema.

Health hazards in the home

Sources of indoor health hazards:

Health effects of poor indoor air quality

Poor air quality in your home can cause:

  • Dizziness
  • Nausea
  • Allergic reaction
  • Eye and skin irritation
  • Respiratory tract irritation

Pay attention to the time and place the symptoms occur to find out if something in your home may be the cause.

Improving indoor air quality at home

You can improve the quality of air at home by removing the source of the hazard. Increasing fresh air in your home by opening a window can also help.

If removing the source and increasing air circulation does not improve your indoor air quality, consider buying an air purifier or air cleaner. Be sure to look for one which is HEPA-certified.

You can also improve air quality at home by:

  • Not allowing smoking in your home
  • Ensuring furnaces, water heaters and fireplaces are checked regularly
  • Storing chemicals in a garage or outdoor shed
  • Choosing natural products
  • Keeping your home's temperature and humidity at comfortable levels


Lead is a naturally occurring metal found in rock and soil. Lead is commonly found in homes due to its earlier uses in plumbing and paint.

Sources of lead exposure

Lead can be found in:

  • The air
  • Soil
  • Dust
  • Drinking water
  • Food
  • Various consumer products
Health effects of lead

Lead can enter the body through the mouth, lungs or skin. Once lead enters the body it circulates in the bloodstream and can affect intellectual and behavioural development, especially in children.

Children are at greater risk of ingesting lead due to their frequent hand-to-mouth activity and tendency to mouth or chew objects.

Reducing lead exposure at home

The Region of Waterloo and local municipalities test for lead in drinking water to ensure all drinking water consistently meets provincial standards.

You can reduce lead exposure if you:

  • Remove shoes when you enter your home
  • Encourage children to play on grass instead of dirt
  • Wash feet if you have been outside barefoot
  • Regularly clean carpets and upholstery using a vacuum with a HEPA filter
  • Use a damp mop or rag to prevent dust from becoming airborne when cleaning
  • Wash fruits and vegetables
  • Wash toys and other items that come in contact with soil or dust
  • Learn about safe gardening practices

For more information about how you can reduce your family’s exposure to lead, please see: Reduce your exposure to lead.

Additional resources about lead

Carbon monoxide

Carbon monoxide is an odourless, colourless and toxic gas that can cause coma or death.

Carbon monoxide detectors are required in all Ontario homes with fuel-burning appliances or attached garages. It is the law.

If your carbon monoxide detector sounds you should leave your home immediately and move to fresh air. Once outside, call 9-1-1.

Sources of carbon monoxide

Carbon monoxide is produced whenever you burn a fuel (wood, gasoline, propane, natural gas, etc.).

In your home, sources of carbon monoxide include:

  • Furnaces or boilers
  • Gas stoves and ovens
  • Fireplaces, both gas and wood burning
  • Wood stoves
  • Water heaters
  • Clothes dryers
  • Generators
  • Vehicles
  • Power tools and lawn equipment
  • Tobacco smoke
Health effects of carbon monoxide

At low levels, effects of inhaling carbon monoxide include flu-like symptoms such as:

  • Tiredness
  • Headaches
  • Shortness of breath
  • Muscle weakness

At high levels you can experience:

  • Dizziness
  • Chest pain
  • Poor vision
  • Difficulty thinking

At very high levels, carbon monoxide can cause:

  • Convulsions
  • Coma
  • Death
Preventing carbon monoxide at home

You can prevent carbon monoxide poisoning if you:

  • Install carbon monoxide alarms in your home
  • Do not use a gas stove to heat your home
  • Check and clean your fireplace, chimney and flue every year
  • Make sure vents for the dryer, furnace, stove and fireplace are clear of snow
  • Never use a barbecue, charcoal grill or hibachi in your home
  • Never use a gas-powered generator in your home


Radon is a gas that is formed by the breakdown of uranium, a natural radioactive material found in soil, rock and groundwater.

When radon is released from the ground into the air outside, it is diluted to low concentrations and is not a concern. In closed spaces, such as a home, radon can sometimes concentrate in higher levels that increase health risks with long-term exposure.

Sources of radon

Radon can enter your home through any opening that contacts the ground such as:

  • Cracks in house foundation
  • Spaces around pipes, sump holes and floor drains
  • Basement windows
Health effects of radon

Long-term exposure to high levels of radon increases your risk of lung cancer.

If you smoke or are exposed to second-hand smoke and you are exposed to radon, you have a higher risk of developing lung cancer due to the combined effects of radon and smoking.

Reducing radon at home

If you have concerns about radon in your home, you can test your indoor air. Health Canada recommends indoor air should have less than 200 Becquerels of radon per cubic metre.

If radon testing shows a radon level of 200 Becquerels per cubic metre or higher, you should take action within two years. If levels are higher than 600 Becquerels per cubic metre, you should take action within one year.

certified radon service provider can help provide you with the most effective radon reduction solution.

Reducing radon in your home can include:

  • Sealing all radon entry points (cracks and openings in foundation walls and floors and around pipes)
  • Closing floor drains that lead to soil
  • Increasing ventilation
  • Smoking outside, if you smoke
Additional resources about radon

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