Air shouldn't stink, especially not indoors.
And yet it did last year at the Gazette. Some strange smell permeated the air and I couldn't pin down its source. Others noticed it too, eventually. We called in the experts and guess what? There was a gas leak in the heating system.
Moments like this illustrate an important point about air pollution: what's outside often isn't as important as what's inside. We spend almost our entire lives indoors, which makes the indoors a major source of pollutant exposure.
That's why I'm here in Warren Kindzierski's house watching some students assemble what looks like a bomb. Kindzierski, a St. Albert resident, is launching the biggest indoor air quality study in Alberta this month and I've decided to tag along.
The great experiment
Kindzierski is professor of environmental health science at the University of Alberta and an air quality specialist. Health Canada has asked him to head up the Edmonton Indoor Air Quality Residential Exposure Study this month to test indoor air and see how it compares to national standards.
This is the most intensive indoor air study ever done in Alberta, Kindzierski says, involving about 50 homes, three teams and a long list of pollutants. The data will take years to analyze and will be combined with four similar studies done elsewhere in Canada.
His students are at his house to practise with their sampling gear. They set up two big black cases and start wrangling rubber hoses, metal boxes and ominous-looking cylinders. Meters click. Pumps whir. The students eyeball digital displays and rattle off numbers.
It's not a bomb, I learn, even if it looks like it. The blue handheld Geiger-counters are trackers that inhale and count tiny bits of dust. The small vertical tube on a stick is a cascade impactor (a series of filters), while the colourful plastic medals hanging from it detect gaseous pollutants. The big cylinder sucks in organic carbon, while the metal bowling ball with the spout in the corner inhales volatile organic compounds.
What's that smell?
Household air quality depends on many factors, Kindzierski says — temperature, humidity, house age — but comes down to what's in the air and how well you can get rid of it.
He singles out the pollutants to watch. Carbon monoxide is an odourless, colourless gas that comes from incomplete combustion — cars, furnaces and cigarettes. It stops your blood from carrying oxygen and is lethal at high doses.
Volatile organic compounds (VOCs) are complex molecules that can be toxic. You smell them in paint, air fresheners, gasoline and more — they're what cause that new-car smell. One notable VOC is formaldehyde. Causing headaches, watery eyes and nose cancer (at high doses), it often leaks out of new furniture or wallpaper. Garages are a notable VOC source as paint and exhaust fumes can easily leak into the house.
Two major pollutants are mould and particulates, notes Tang Lee, a professor of architecture and a renowned air quality expert at the University of Calgary. There are about 200,000 species of mould known with effects from toxic to beneficial. It's everywhere but it can't thrive unless it has moisture and food — typically dust, wood or paper.
Particulates include everything from dust to tobacco smoke and come from pets, food and carpets. "The large dust you see is not harmful to you," Lee notes; it's the micron-sized stuff that damages your lungs.
Sniffing for trouble
Most people won't have Kindzierski's gear available to test their air. I didn't, so I called in Mike Smith of DF Technical & Consulting Services to look at my house and the Gazette office.
Smith says he's usually called when an owner has a specific problem: a smell you can't identify, big mould patches or strange headaches. Much of his work relies on deduction. An air-freshener could suggest improper cleaning, for example, while mould hints at water intrusion.
Smith heads to the office for an air quality survey. He smells a problem right away: VOCs from printer's ink. He shouldn't smell them, he says, because the office should be pressurized to keep them in the press area.
"Look at your diffusers," he continues, pointing to the blacked vents in the ceiling. "They're filthy." This suggests the ventilation system is having a hard time forcing air in and out of the office.
His real-time air monitor confirms his suspicions. Carbon dioxide levels in the office did not drop significantly overnight, suggesting a poor rate of air exchange. The detector also found minor levels of carbon monoxide in the office — likely from vehicles in the press — suggesting improper pressurization. He recommends we call a specialist to clean and pressure-balance our ventilation system.
He moves on to my house for a mould audit. He sets up a sticky slide on a vacuum pump to see if there are any mould spores in the air. He doesn't find any, but that doesn't necessarily mean we're mould-free.
He spots one possible source in the bedroom. "Airflow is the only way to keep moisture off glass," he says, and we've left the blinds closed. He opens them and finds condensation along the bottom of the window frame. "That's your water source," he says, and any dust there would be a food source for mould.
Bathrooms are another problem area for mould, as they're warm, wet, and full of food. Faulty vent fans can let moisture build up, while tile grout can absorb water, creating hidden mould on the drywall behind.
Smith's handheld moisture detector doesn't find anything behind my shower tiles, but beeps like a hyperactive metal detector when he puts it behind the toilet. Turns out that a water valve had broken that morning. "That piece of wood is about 75 per cent moisture," he says, indicating the floor under the valve. I fix it immediately.
Clearing the air
Bad air can be can be very expensive or hazardous if left undetected. Smith recalls one Edmonton homeowner who had a $64,000 mould-repair job because they ignored a strange smell from their basement for two years.
"A lot of the jobs we do that are memorable are purely [due to] neglect," he says. "If you don't get on top of [a problem] quickly, you will have trouble."
Stains and moulds are signs of other problems that need to be fixed (such as leaks), Lee says, and should not be ignored. "What's really important is house hygiene."
That includes cleaning up water spills and vacuuming regularly, preferably with a central vacuum that vents to the outside. (Most portable models simply blow fine particulate matter back into the room.)
Limit your pollution sources as well. Stay away from carpet, Smith says, as it's a major source of particulates. Keep idling cars, paint and cleaners out of your garage and avoid cigarettes and scented products indoors.
Don't even bother with ozone generators, Lee says. They might create a "fresh air" smell but they also produce ozone — a pollutant that makes smog. "They have absolutely no benefit to air."
Proper ventilation can help clear any pollutants that remain, Kindzierski says. "One way to exchange air and heat it up quicker is to keep your basement door open," he notes; that gets more air to your furnace. Also, make sure your return air vents are unobstructed. "People put furniture in front of them and wonder why the air smells stale."
Unlike outdoor pollution, indoor air quality is almost entirely under our control. Health Canada has piles of simple guides available to help improve the air in your home. Air analysis is complex science, but keeping it clean is simple — if it stinks, fix it.
