Special to the Sun

May 14, 2005

With spring in the air and summer just around the corner, many of us are spending more time outside enjoying the sunshine and fresh air. Despite this call to the great outdoors, however, research indicates that most people spend approximately 90 per cent of their time indoors. While we often consider our homes havens from the haze of smog created by car exhaust and industrial emissions which even Vancouver suffers through during warmer months, a growing body of research suggests that the air we breathe indoors is often more polluted than the outdoor air of large, industrialized cities.

Our contemporary energy-efficient, draft-free homes exacerbate indoor pollution problems by reducing the rate at which outdoor air replaces indoor air. When there is little infiltration (little cracks that let in drafts) or insufficient natural or mechanical ventilation, the air exchange rate is low. This, coupled with the numerous emission producing sources in our homes, makes indoor air particularly susceptible to high pollution levels. Nearly everything we do or bring into our homes contributes to indoor air quality (IAQ). The following are just a few of them.

TOXIC HEAT

While we all enjoy toasty rooms, crackling fires and hot meals on cold winter days, the combustion equipment creating our heat — unvented kerosene and gas space heaters, chimneys and furnaces, and gas water heaters and stoves — can contribute to increased levels of carbon monoxide (CO), nitrogen dioxide (NO2), and air borne particulates in the indoor environment.

INTERIOR FINISHES

There is nothing like the look and feel of freshly painted walls, new kitchen cabinets, or a recent furniture purchase. Unfortunately, these interior products and many others can contain and emit formaldehyde including: particleboard, hardwood plywood paneling, medium density fiberboard (MDF), permanent-press textiles, many glues and adhesives, and some paints and coating products.

SPIC AND SPAN

Your air freshener is “mountain breeze,” the dish soap is “lemon fresh,” and the toilet bowl cleaner claims “great bleaching action.” Smells squeaky clean, but your indoor air is now a veritable soup of volatile organic compounds (VOC), or organic chemicals. Used as ingredients in many household products — paints, cleaners, cosmetics, and hobby products — VOCs are released not only when you use a product but also when they are stored. In the absence of adequate ventilation, high pollutant concentrations can remain in the air long after these activities are finished.

THAT ‘M’ WORD

Moisture — water-damaged materials, wet surfaces, and high relative humidity — can serve as a breeding ground for biological contaminants such as molds, mildews, bacteria, and insects. Microscopic arachnoids and house dust mites, which thrive in damp, warm environments, are responsible for one of the most powerful biological allergens.

RADIOACTIVE ROCKS

Absent from B.C.’s coastal regions, radon concerns many homes in the Interior and east of the Coast Mountain range. Radon gas, which comes from uranium-bearing soil or rock, enters homes through cracks in walls and floors, floor drains, and sumps. Studies indicate that from one to five per cent of all homes in the interior of BC may have unacceptable radon levels.

CLEARING THE AIR

A number of symptoms can result from poor indoor air quality including irritation of the eyes, nose, and throat, headaches, dizziness, and fatigue. Repeated and long term exposure has been linked to serious conditions such as respiratory illness, heart disease, and cancer. Fortunately, there are changes you can make that directly affect and improve indoor air quality.

SOURCE CONTROL

Eliminating or reducing individual culprits is generally the most effective (and cost-efficient) way to improve indoor air quality.

– Have central air handling systems, including furnaces, flues, and chimneys, inspected annually and promptly repair cracks or damaged parts.

-Insure that you have a CO monitor for your combustion furnace.

-Carefully consider everything you bring into your home — use non- and low-VOC paints, glues, and other products; switch to natural cleaners such as vinegar and baking soda.

-Ask interior decor retailers about the materials used in their products.

-Properly dispose of partially full containers of old or unneeded chemicals.

VENTILATION

If you cannot eliminate the source, be vigilant about ventilation. Bathroom and kitchen fans that exhaust outside remove contaminants from the room and can also help increase a home’s overall air exchange rate.

-Help control moisture by installing a humidistat that turns on fans when relative humidity goes above 50 per cent.

-Take heed when product labels call for a “well ventilated area.”

-Install a heat recovery ventilator (air-to-air heat exchanger), a mechanical system that increases air exchange rates without compromising energy efficiency.

AIR CLEANERS

Unfortunately these devices are generally not designed to remove gaseous emissions. While they can help reduce pollutants and allergens such as dust mites, pet dande and smoke, they should not be considered substitutes to efforts to eliminate or dramatically reduce emission sources and to improve air exchange.

Want some assistance clearing the air? Here are a few resources that can help.

CMHC, The Clean Air Guide

US EPA.

http://www.epa.gov/iaq/index.html

B.C. Ministry of Health Services

UBC School of Occupational and Environmental Hygiene, Dr. Karen Bartlett

© The Vancouver Sun 2005