How to improve your home's air quality
By Fiona Wagner • Bankrate.com

I recently read an article in my local paper about a 130-year-old church rectory that may have to be demolished because of extensive mold damage. The hazardous mold, hidden inside the walls behind the original plaster, was only discovered when some pipes burst during a cold snap, though the occupants had suffered from allergy-induced asthma symptoms for years.

This got me thinking. My family and I will be moving soon to a 100-year-old house, and although the home inspector gave us a clean report, I wondered whether my home was more at risk of developing air quality issues than a newer home.

"You can have different kinds of pollutants, but any home of any age can become contaminated," says Virginia Solares, a senior researcher with the Canada Mortgage and Housing Corporation.

She says older homes may be more likely to have mold problems because of leaky basements, but new homes are increasingly airtight, often with insufficient ventilation, and may be constructed with building materials that can produce noxious emissions.

Canadians spend about 70 percent of their time in their homes, both old and new, so it's important to be familiar with some of the more common biological and chemical air pollutants that can have an impact our health and well-being.

As one in five Canadians suffers from respiratory diseases such as asthma, emphysema and lung cancer and an even greater numbers suffer from allergies, the importance of having good quality air in our homes can't be underestimated. So read on to find out what to watch for and what you can do to improve the quality of air in your home.

Know your irritants
According to the CMHC, indoor air pollutants range from minor irritants, such as dust or animal dander, to serious irritants such as molds or chemical vapours. Although we often read about the dangers of toxic substances -- such as asbestos or Urea-Formaldehyde Foam Insulation (UFFI) -- mold, combustion gases and tobacco smoke are the most common indoor air contaminants.

Molds are microscopic fungi that thrive in damp environments created by poor ventilation, flooding or building leaks. They can also be found in humidifiers, air conditioners, carpets and bathroom surfaces. Large concentrations of mold release spores that may cause nasal congestion, cough, eye irritation, fatigue and difficulty concentrating. It can also exacerbate pre-existing conditions such as allergies or asthma.

Carbon monoxide is a colourless, odourless gas produced by the incomplete combustion of any material containing carbon, which includes our most common heat sources -- natural gas, propane and oil. Carbon monoxide in the home can come from faulty or improperly vented furnaces and appliances. Carbon monoxide poisoning can cause headaches, tiredness, impaired motor skills and even death at high concentrations.

Nitrogen dioxide, a reddish-brown gas with a pungent odour, can be found in homes with improperly vented combustion appliances and gas stoves, ranges or water heaters. Long-term exposure may contribute to an increased risk of developing a respiratory disease.

Tobacco smoke is a complex mixture of more than 4,000 chemical compounds, of which at least 50 are believed to have adverse health effects such as cancer and emphysema. Second-hand smoke irritates the eyes, nose and throat, causes headaches and nausea and aggravates pre-existing respiratory conditions.

Toxic problems to watch out for
Asbestos is a mineral fibre once used for fireproofing, heat insulation and noise insulation. Many older homes may still have asbestos-containing material on their pipes, boilers or walls, but it's only risky when the fibres are disturbed and released into the air. The lungs can't expel inhaled asbestos fibres, and long-term accumulation can cause cancer and lung damage.

Formaldehyde is a colourless, pungent gas that can be found in pressed wood products --such as particleboard or medium density fibreboard -- fabrics, aerosol cans and old insulation. Between the 1970s and 1982, UFFI was used in homes as insulation that unfortunately released formaldehyde as it aged. Exposure can cause skin rashes and irritation of the eyes, nose and throat.

Volatile organic compounds, or VOCs, are chemicals that easily emit vapours at room temperature. According to the Canadian Health Network, the best-known VOCs are petroleum products such as motor fuels, formaldehyde and acetone, which can leak from construction materials such as foam insulation, paint, carpets, linoleum and floorboards. VOCs can cause eye, respiratory and digestive tract irritations, headaches and nausea.

How to improve your home's air quality
Usually, the most effective way to improve your home's indoor air quality is to eliminate specific sources of pollution or reduce their emissions. For example, a boiler covered with asbestos insulation can be coated, and gas stoves can be adjusted to vent more efficiently.

"Canadians should be concerned but not scared," says Nicolas Gilbert, a senior evaluator with Health Canada's Air Health Effects Division. "For all of these problems, there are ways to prevent them."

Here are 10 practical steps you can take to improve your home's air quality:

1. Keep the relative humidity -- the amount of moisture in the air relative to the amount the air can hold at a certain temperature -- below 50 percent in the summer and below 30 percent in the winter. Have fans professionally installed in areas with excessive water vapour, such as bathrooms, and dehumidify damp basements.

2. Repair leaky roofs, walls and basements to reduce moisture buildup.

3. Grade your yard to channel water away from your house, and ensure downspouts and eaves troughs are positioned properly.

4. Clean moldy surfaces as soon as they appear with a strong detergent. Have larger areas treated professionally.

5. Ensure regular maintenance and proper venting of the furnace and all combustion appliances. Install a carbon monoxide detector to alert you of any leaks.

6. Reduce the amount of clutter in your home, especially the basement, as excess books, clothes, paper and furniture absorb dust and moisture.

7. Minimize the use of harsh chemicals, cleaners and deodorizers. Use unscented cleaning compounds.

8. Choose building and renovation materials (flooring, carpets, etc.) with low levels of chemical emissions.

9. Ensure your home has sufficient ventilation, especially when partaking in activities that can generate high levels of pollutants, such as painting. Open windows and doors or operate window and attic fans in nice weather, or invest in a mechanical system designed to bring outdoor air inside the home.

10. Don't smoke in your home.

Fiona Wagner is a freelance writer based in Georgetown, Ontario.