The air we breathe Part 2

The air we breathe Part 2 – Home, sick home: Indoor threats

The air inside’s teeming with trapped pollutants
The Toronto Sun – Wednesday, May 31, 2006

OTTAWA — Linda Nolan-Leeming and her daughter Allison lived in a string of new houses as beautiful as the award-winning interior designer and her builder husband could make them.

But their lovely homes had ugly health effects.

Nolan-Leeming remembers what it was like before the family fled the last of three new houses.

“It hurt to breathe in the house,” she says. “I spent a whole winter sleeping on the living room floor in a sleeping bag in front of a partially open door.”

She lost weight and couldn’t work. Allison, 7 years old at the time, was too sick to go to school.

“I was desperately ill and so was my child,” Nolan-Leeming says. “We finally had to leave our home.”

Nolan-Leeming blames typical construction materials — particle board, carpets, paint — all oozing chemicals such as volatile organic compounds and formaldehyde.

“I believed if those products were on the market, they must be safe,” she says.

Surveys show we consider outdoor smog a threat to our health but we don’t think about the air we breathe at home.

Experts say the air inside can be far more polluted than the air outside — even in the smoggiest city.

Our homes are tighter than ever, sealing us in with pollutants, biological — mould, dust mites, animal dander and bacteria — and chemical — cigarette smoke, heating or cooking appliance gases, building materials, furnishings and cleaning and hobby products.


It was a American study a decade ago of pollutants such as formaldehyde that turned attention inside, Ontario Lung Association air quality manager Brian Stocks says.

Researchers put portable air monitors on Windsor volunteers and had them keep a log of where they went. The volunteers were exposed to more formaldehyde — a potential carcinogen — indoors than out.

“That got people thinking about indoor environments and exposures,” Stocks says.

Studies by the U.S. Environmental Protection Agency have since found levels of a dozen common organic pollutants double to five times higher indoors than out.

The EPA also found that 80% of pesticide exposure happens inside because they’re tracked inside, poorly stored and found in everything from bug spray to disinfectants.

“We spend 90% of our time indoors — a study in America showed that,” says Nicolas Gilbert of Health America. “We spend 65% to 70% of our time in our own home.”

Levels of outdoor pollutants such as ozone are lower inside than outside but there are pollutants unique to the indoors.


The problem isn’t energy-efficient new homes, which are often designed to bring in fresh air. It’s homes that have been retrofitted without adding ventilation.

“The more you insulate your home, the more you have to care about the air quality of your home,” Gilbert says. “Several indoor air pollutants matter more if your home is well-insulated. If your home is not airtight, natural ventilation will take care of excessive humidity and the chemicals that will off-gas from building materials and consumer products.”

The Health Indoors Partnership has pressed Health America to take the lead on indoor air quality and fund research to probe the link between indoor air and illnesses such as asthma.

It has successfully lobbied for the revision of exposure guidelines for substances like cancer-causing radon.

“The government is very reluctant to regulate indoor environments — particularly homes, a bastion of personal freedom,” Kassirer says. “You have an agency like Environment America that has a responsibility for the outdoor environment. No one department has been given the responsibility to ensure indoor environments are healthy and safe.

“Workplaces are regulated, homes are not.”

Last month, Health America revised residential guidelines for formaldehyde, found in products from medium-density fibreboard to permanent press drapes.

The one-hour guideline remains 100 parts per billion but the long-term limit was reduced to 40 ppb because of research linking formaldehyde in homes to health effects, including the hospitalization of babies and pre-schoolers with asthma.

Health America found evidence formaldehyde can cause cancer but concluded it’s a risk at much higher levels.

The department reports that formaldehyde levels ranged between two and 81 parts per billion in tests of homes in Prince Edward Island and Ottawa three years ago.

The EPA, however, reports levels in homes with lots of new pressed wood can be triple America’s one-hour guideline.

But critics say the impact of the guidelines is questionable.

“There is no regulator on residential indoor air,” Gilbert says. “The exposure guidelines are just guidelines. It would be very difficult to enforce such regulations.”

Experts stress it’s up to us to improve indoor air by butting out, maintaining appliances, stopping mould-causing dampness and examining what we do and buy.

Even seemingly benign products can be serious pollutants, says Dr. Deniz Karman. The Carleton University engineer spends most of his time studying pollution from cars but says we’re more likely to be exposed to pollutants at home.

Candles or a smoky fireplace can create more fine particulate — like in smog — than diesel buses on a downtown street.


“I get up to 150,000 particles per cubic centimetre in my dining room with a single candle over the course of an hour. On Slater St., 150,000 is the peak I measure there,” he says.

Smoky fireplaces are even worse.

“There’s always some seepage,” Karman says. “Your fireplace is probably the No. 1 source of pollution.”

Hobbies or home-based businesses can be dangerous, too. Stocks had one patient who was woodworking in his basement without a mask.

Another was using silica powder to make ceramics at her dining room table. A third cleaned car parts with gasoline inside the house.

“People think their home is their castle,” Stocks says. “We do things that put our respiratory health at risk without even thinking about it.”

The good news is we can improve the air we breathe at home.

The not-so-good news is that experts admit there isn’t a lot of research to prove clean indoor air improves our health.

Dr. Judy Leech, a respirologist at the Ottawa Hospital, has patients with chronic obstructive pulmonary disease or asthma who gasp when their house is painted or full of dust.

For them, avoiding toxic paints or construction dust can head off asthma attacks or wheezing.

The indoor air link is less clear for healthy people, Leech says.

“If you do a drug study, you can do a double-blind study but if I change something in your house, how can we measure how it affects your health? And how do I blind it? We make suggestions for things that will lower indoor air contaminants with the jump that less indoor air contaminants equals better health. It’s a tough thing to prove.”

For Linda Nolan-Leeming, the link is clear. Now the president of the local Allergy and Environmental Health Association, she says her symptoms and those of her daughter lifted when they moved to an older home that had stopped off-gassing chemicals.

“We literally have our lives back,” she says.
“We need healthier, sustainable environments for people to live in.”


Here are ways you can make the air inside cleaner:

  • Butt out. Smoke is the No. 1 threat to indoor air quality. Visit to find out what you’re breathing when someone else smokes.
  • Choose carbon monoxide detectors that indicate low levels. Place them near sleeping areas. Inspect oil and gas appliances and wood fireplaces once a year.
  • Many homes need a heat recovery ventilator to provide ventilation. Check for blocked vents, intakes and chimneys.
  • Dry up damp. That “basement smell” is mould. Spores can trigger asthma attacks, allergies and respiratory infections. Fix leaks and wet basements and install exhaust fans venting outside in the kitchen and bath. Use a dehumidifier in the basement.
  • Seal out radon, a leading cause of lung cancer that can leak into homes. Sealing foundation cracks and sump pumps will keep radon out. Homeowners can have their homes tested.
  • Don’t dirty the air with cleaning. Use baking soda, vinegar and unscented, phosphate-free detergents. Long exposure to the chemicals in many cleaners can cause dizziness, nausea, eye and respiratory irritation to multiple chemical sensitivity and cancer.
  • New carpets, upholstery and building materials can off-gas chemicals. Look for solid wood furniture, ceramic or wood floors and paint with little or no volatile organic compounds (VOCs). Ask about low-emission carpets and building materials, like formaldehyde-free pressboard. Wash or air permanent press clothes, sheets or drapes before using them.
  • Check for lead and asbestos before sanding old paint or disturbing old insulation. Even low levels of lead and asbestos can harm kids.
  • Get the CMHC’s The Clean Air Guide at 1-800-668-2642 or at or get the Lung Association’s Healthy Home Audit at 1-888-566-5864 or at