Could Your House Be Causing Allergies and Asthma?

in Healthy Home, Indoor Allergies
Published: June 30, 2010

Of concern for individuals with asthma and allergies: the most common problems were high levels of particle allergens and chemical pollutants.

Poor indoor air quality has been linked to a number of health effects. Chemicals and airborne allergens can trigger wheezing, shortness of breath, itchy eyes and runny noses. Nitrogen dioxide, from second-hand smoke and unvented gas stoves and furnaces, leads to eye, nose and throat irritation as well as respiratory infections in young children.

Formaldehyde can cause breathing distress and can nauseate, as can pesticides. Some chemicals, in instances of high-level exposure, can be cancer-causing.

So how did our homes get so polluted? The North American lifestyle is much to blame. We spend on average about 90 per cent of our time indoors, and 65 per cent of our time in our own residences. “Home air” is what we breathe most often, and which we readily (and naively) pollute with products used to keep ourselves primped and our homes polished.

Anything with an added scent – from shampoo to laundry detergent, fabric softener and all-purpose cleanser – releases chemicals that hang on you and your clothes and linger in the air. That bouquet of lemon or citrus in products used to make our home sparkle in some cases will also mask dangerous chemicals in the cleaner, such as formaldehyde and ammonia.

Prone to being house proud, we renovate and decorate, and that means fresh paint, new carpets and pressed-wood products (such as kitchen cabinets, countertops and furniture). These usually emit gases called volatile organic compounds, such as formaldehyde. People sensitive to VOCs, including asthma sufferers, may react to very small concentrations.

Then we shower often and don’t always use exhaust fans when cooking, creating humid environments in which mold and dust mites thrive. On the surface our surroundings are clean and comfortable. But like the walls in Michele Chase’s home, it’s what is going on unseen that becomes the cause for concern.

The explosion of asthma and environmental allergies in the past two decades has grabbed the attention of scientists, environmentalists and government, and they are examining the connection of that phenomenon with the air in our homes.

In September, the National Institute of Environmental Health Sciences in the United States released an analysis of 14 studies, concluding that measures to reduce exposure to house dust were associated with a 26 per cent reduction in asthma.

Then in October, the American Journal of Respiratory and Critical Care Medicine published a study that found people regularly exposed to cleaning sprays and air fresheners were between 30 and 50 per cent more likely to develop asthma.

Meantime, late this past summer, a researcher at the Lawrence Berkeley National Laboratory in California examined 21 studies that looked at the relationship between chemicals and asthma in children, and found the studies identified formaldehyde (or being exposed to particleboard), phthalate dust (or being in the presence of plastic surfaces) and recently applied paint as risk factors for asthma in children.

Renovation and cleaning, new furniture, carpets and textile wallpaper also appeared to increase the triggering of asthma. However, the author cautioned that more study was needed – and more investigation into what was actually causing the asthma in these kids.

Understanding the interaction between environmental exposures and genetic factors in allergies and asthma is part of the mission of AllerGen, Canada’s allergy, genes and environment network, and its ambitious CHILD cohort study.

That project is designed to follow thousands of children and their families from birth to determine what role environments (indoor and outdoor) and genetics play in the development of allergies. Dr. Tim Takaro, a physician-scientist and associate professor at Simon Fraser University in Vancouver, is involved in CHILD and has already contributed research from his own studies of indoor air quality in homes in the United States.

Though the research is young, his and others’ early findings are profound – suggesting that combinations of allergens and particulate matter may actually unite and become a bigger beast. “For example, diesel smoke and dust mite allergen, when they’re combined, are much more potent than either one alone,” says Takaro.