Here are some ways you can protect indoor air quality at home:

• Do not allow smoking inside your home
• Check furnaces, water heaters and fireplaces regularly
• Store chemicals in a garage or outdoor shed
• Choose natural products
• Keep your home's temperature and humidity at comfortable levels
• Increase ventilation in your home

There are ways you can increase ventilation in your home to improve air quality.

• Ensure proper ventilation to the outside when using combustion appliances like fireplaces, wood stoves, gas stoves and furnaces
• Open windows when outdoor air conditions are good
• When possible, use mechanical ventilation such as a properly maintained HVAC (heating, ventilation and air conditioning) system
• Increase ventilation and always read and follow label instructions when using products such as:
• Cleaning products
• Glues
• Paints
• Varnishes
• Adhesives
• Avoid smoking indoors
• Choose low-emission products when possible
  • Some composite wood products, paints, varnishes and chemical cleaning products may emit fewer chemicals than others
  • Store products properly 
• Ensure there is a good seal around any doors connecting the house to an attached garage

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

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

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

Hydrogen sulfide occurs naturally in some environments like abandoned water wells, gas wells, sulfur springs, swamps, etc.  

It can be found in industrial facilities, animal farms, sewers or sewage treatment plants.

It is found naturally in crude oil, natural gas, volcanic gases and hot springs. Sometimes certain environmental conditions causes it to be released from these sources into air and water. 

Private well owners who notice a rotten egg smell in their water can find more info on our private wells page.

People can usually smell hydrogen sulfide at very low levels (0.0005 to 0.3 parts per million (ppm)), but smell is a poor indicator of the levels in the environment.

Special equipment is required to measure levels of hydrogen sulfide.

Hydrogen sulfide can enter your body by breathing it in, eating or drinking something contaminated with it, or when it touches your skin.

It is broken down rapidly by the liver and is excreted in urine.

Exposure is only likely to occur if there is an ongoing source. The presence of hydrogen sulphide in confined spaces is of particular concern because high levels of the gas may accumulate.

Short-term exposure to low concentrations (10-100 ppm) of hydrogen sulfide may cause:

• eye, nose or throat irritation
• difficulty breathing for some people with asthma 
• headaches
• poor memory
• tiredness
• balance problems

Brief exposure to high concentrations of hydrogen sulfide (greater than 500 ppm) can cause a loss of consciousness. In most cases, the person will likely regain consciousness without any other effects. In some people, there may be permanent or long-term effects such as headaches, poor attention span, poor memory and poor motor function.

If you notice a rotten egg smell near your home and suspect hydrogen sulfide, contact Ontario's Spills Action Centre.

If you notice the smell inside your home call your local fire department. 

Lead can be found in:

• The air
• Soil
• Dust
• Drinking water
• Food
• Various consumer products

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.

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

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

• Lead in Drinking Water (fact sheet)

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

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.

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.

A 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

• Radon: What You Need to Know
• Reducing Radon in Your Home
• Take Action on Radon