Topic Overview

Exposure to indoor air pollutants can cause respiratory problems, such as asthma attacks, or diseases, such as lung cancer. Pollutants include smoke, pet dander, radon, mould, cleaning products, and other chemicals. You can create a healthier home by following the tips below.^{footnote 1}

Reduce allergens

• Groom pets often to reduce dander. Don't allow them to sleep in the bedroom with anyone who has asthma or allergies. If possible, keep them off carpets and furniture.
• Choose window coverings that are easy to clean, such as wood shades or blinds. Drapes are magnets for dust.
• Check houseplants for mould. Repot or move them outside if the soil contains mould.
• Do not allow anyone to smoke in your home.
• Eliminate carpeting and replace it with wood or tile flooring, if possible.
• If the humidity level is more than 50% inside your house, dust mites and moulds can be a problem. To control dust mites, get allergen-resistant covers for bedding. Wash sheets and blankets in hot water.
• Use high-efficiency bags in your vacuum cleaner or install a central vacuum system in your home.
• Don't store firewood indoors. Drying green firewood can contain mould spores.
• Keep trees and shrubs at least 1 m (3 ft) away from your house. Roots can provide an easy path for water into your basement or crawl space.
• Keep washrooms, kitchen, and basement—places where allergens are likely to grow—clean and dry.

Control moisture

• Fix leaks and other sources of water intrusion, and remove water-damaged materials.
• Make sure your clothes dryer vents to the outside.
• Install and keep clean hood exhaust fans in your kitchen. Make sure washroom vents exhaust air outdoors and not into basements, crawl spaces, or inside the house.
• Make sure that exhaust fans don't draw too much air out, creating a negative-pressure situation in which the pressure inside the house is lower than outside. Negative pressure can reverse the flow of combustion gases from furnaces, gas stoves, and water heaters, and draw water vapour and dangerous carbon monoxide or nitrogen dioxide into your home.
• Caulk the interior and exterior of your home, especially around windows and vents.
• If you're building a new home, install a waterproofing system that keeps moisture away from your foundation.
• Keep gutters and drains clean.
• Remove any water-damaged carpet. Replace it, if possible, with wood or tile flooring.

Avoid heating problems

• Make sure fuel-burning furnaces, hot water heaters, and gas ranges are checked every year to ensure air intake and exhaust systems are adequate. It is best to have your water heater and furnace outside of your home—for example, in your garage.
• Do not use kerosene space heaters or unvented gas heaters as your primary source of heat.
• Install a carbon monoxide detector in your home. Carbon monoxide is odourless and colourless. You may not notice it until you have health problems. If you see orange or sputtering flames in your gas furnace or stove, it may mean that you have a problem with carbon monoxide. Call a technician immediately.
• Make sure wood stoves and fireplaces have tight-fitting doors. Check flues and chimneys for cracks that could allow fumes into your house.

Check household furnishings

• Many furnishings contain formaldehyde and other organic compounds. When shopping for new furniture or cabinets, try to buy those that are made of solid hardwood, not particle board, which usually has a wood-veneer finish. The wood veneer may be attached with glue that contains formaldehyde.
• If someone living in your home has asthma, replace carpet with tile or wood flooring. If carpeting is necessary, use a product with a short nap, or use area rugs that can be cleaned regularly.
• If you are remodelling, use gypsum board, plaster, or real wood for walls. Plastic or wood-fibre panelling may emit formaldehyde.
• If your house was built before 1978, the woodwork or other surfaces may be covered with lead paint. You can have the paint tested for lead. Do not sand or strip off the lead paint. But you can cover surfaces with wallpaper or other building material. Call an expert if you have to remove lead paint.

Be careful with household products

• Take care when using cleaning products, paints, solvents, and pesticides. Try not to use them inside the house. If you must use them inside, use a fan to blow strong odours and fumes out of your home. Be aware that paint can release trace gases for months after you apply it. Try to use paint without volatile organic compounds (VOCs).
• Use non-toxic glue to install flooring or carpet.
• If you strip furniture inside, use products that do not contain methylene chloride. And make sure you have enough ventilation.
• Do not mix cleaning products. Consider using natural cleaners, such as vinegar, lemon juice, boric acid, or baking soda.
• Chemicals found in many air fresheners, toilet bowl cleaners, mothballs, and other deodorizing products may be harmful to the lungs.^{footnote 2} Use alternatives. For example, baking soda absorbs odours and can be used instead of an air freshener.
• Don't keep items you're recycling—such as newspapers, rags, cans or bottles—inside your home. They can be sources of toxic vapours.
• Install a radon monitor in your home on the lowest level that you regularly use.
• Make sure sump basins are sealed and vented to the outdoors.

Improve air ventilation

• Make sure your house gets an adequate supply of fresh air.
• Place an air filter in your bedroom, and clean it every 3 months.
• Air conditioning helps keep pollen and other allergens out of your home, but filters must be kept clean.
• Change furnace and air conditioner filters every 2 to 3 months.
• Use exhaust fans in kitchens and washrooms to vent air outdoors.
• Have older homes checked for asbestos insulation on furnaces and pipes. Make sure you use an inspector familiar with asbestos issues.
• Clean humidifiers and dehumidifiers often.
• Make sure outdoor fresh-air intake vents for ducted heating and air conditioning systems are located above ground and are upwind from sources of contaminated air, such as idling cars or trucks.
• Have ducts for forced-air furnaces cleaned, if needed.
• Make sure ducts are sealed to prevent air leakage and to keep contaminants from coming into your home.
• Check that plumbing drains in your home have full water traps and are connected to a venting system. A sewer smell coming from a sink or water appliance is a sign of poor ventilation.