Could Your House Be Causing Allergies and Asthma?

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

From the Allergic Living archives: With allergies, home air is a big concern. We’ve sealed ourselves indoors with a toxic stew of gases, dust and mold. Learn the issues, and what can be done.

Photo: Getty

AS A kid, Michele Chase had severe asthma attacks, which her family put down to the polluted outdoor air in a suburb of Toronto. But at the age of 10, she moved with her family to Fredericton, New Brunswick, a city with a population of only 50,000. Surprisingly, Chase’s bouts of asthma did not improve.

Her chest would become tight and she’d wheeze so hard she couldn’t catch a breath, despite a daily course of medication. Her family became acquainted with the local ER department.

But there was a difference in Fredericton: many of her asthma flareups started within the family home. For years, she couldn’t figure out the exact trigger. But Chase, now 28, today is certain she knows the spark for her childhood agony.

Asthma Attacks from Home’s Air

A few years ago she helped her mother renovate the family home. As they were replacing the gyprock and paneling in the basement, they made an unsettling discovery. Thick, oozing black fungus had completely covered the back side of the gyprock and had permeated the insulation.

While they knew the basement was always damp, they had been completely unaware of the health hazard hidden behind the walls. Chase is thankful her bedroom was not in the basement, but notes, “if it’s in the home, it’s still in what you breathe.”

In Ottawa, Susan Clemens can relate. She watched with increasing distress as her child Angela*, then a toddler, suffered frightening asthma attacks. The family was living in a small apartment building with 12 units connected to a central hallway.

The building’s owners were busily renovating apartments, and every time a tenant moved out, they would resurface the floor in the vacated unit. Chemical fumes permeated the building, and the Clemens’ immediate neighbor was a smoker, so the family was also breathing in second-hand smoke.

Angela was not a wheezer, but during attacks the skin between the toddler’s ribs and collarbone would suck in as she struggled to breathe. Her lips would turn blue, and she’d break into a sweat. Angela was diagnosed with asthma at 12 months, but didn’t see a respirologist until she was 3.

He asked about their lifestyle. When they explained about the apartment renovations, he immediately connected that to their daughter’s health. “That’s one of your big problems,” she recalls him saying. And then the life-changing words: “You have to move.”

While most North Americans still think of smog as the most serious form of air pollution, a more toxic chemical stew is often found in the air we breathe inside our homes. The U.S. Environmental Protection Agency labels indoor air one of the Top Five environmental health risks, up there with polluted drinking water.

The bad environment in our households starts with polluted air from the outdoors, which is often not cycled effectively in and out of tightly sealed and energy-efficient homes. Trapped, “the pollutant levels may be two to five times higher inside than outside, and in some cases, 100 times higher,” says Tom Kelly, director of the EPA’s Indoor Environments Division.

Then the homeowners mix in other chemicals: pesticides, perhaps cigarette smoke, air fresheners, hairspray, perfume and cleaning supplies. Thrown into the invisible concoction are the gases given off by furnishings or paint. Add animal dander, dust mites and mold – those ubiquitous biological allergy triggers – and suddenly there’s new meaning to the term “the fresh outdoors.”

Polluted indoor air “can be a very high risk for children, for elderly people, and for folks with diseases such as asthma,” says Kelly.

To get a reading on just how bad household air is becoming a company that designs indoor air monitors, AirAdvice, worked with a network of heating, air conditioning, and air quality professionals to collect and analyze about 1.3 billion air samples from nearly 50,000 homes in the U.S. and Canada between 2004 and 2006.

Its survey showed 96.7 per cent of the homes generating an “alert”, that is, a level outside the recommended range for one of: particle allergens (dust, dander and pollen); chemical pollutants; carbon dioxide; temperature; humidity; and carbon monoxide. Eighty-three per cent of the homes had two or more alerts.

Why is Home Air so Polluted?

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.

VOCs, Phthalates, Paint

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 few 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.

The National Institute of Environmental Health Sciences 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 the American Journal of Respiratory and Critical Care Medicine published a study in 2007 that found people regularly exposed to cleaning sprays and air fresheners were between 30 and 50 per cent more likely to develop asthma.

As well, 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 CHILD cohort study.

That project has followed 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.

He says it’s important for consumers to think of indoor air pollution as whole, rather than its parts, to see an improvement in symptoms such as asthma flaring or wheezing episodes. “Go after all of the chemicals, go after all of the allergens and you’ll have a more healthy home,” he counsels.

Become Aware of Indoor Air Pollutants

Yet in North America, there is still a lot of confusion among consumers and controversy among researchers, industry and government over exactly which substances are potentially harmful, and at what levels.

In the U.S., while the EPA does not have authority to set rules for indoor air – the way it does for outdoor air – it can make recommendations and educate. At the Health Canada agency, staff are reviewing all of the dated residential indoor air guidelines, and so far have released new ones for mold and formaldehyde. (The recommended limit for an eight-hour exposure to formaldehyde was reduced to 40 ppb, down from 100 ppb, a level set 20 years ago.)

Nicolas Gilbert, the head of Health Canada’s Indoor Air Quality section, says he and his colleagues are also developing a list of additional substances for which guidelines need to be set. Source concerns in the home include everything from paint, VOC content in consumer products, air fresheners, household cleaners, hairsprays and detergents.

Kelly of the EPA notes that people have a much greater awareness of a home’s cosmetics than they do of the air. “They are much more likely to be concerned about changing the kitchen cabinets than they are with improving their exhaust system and ventilation.”

However, once aware, the individual can take control over the air in his or her own living space. Virginia Salares, a researcher at the Canada Mortgage and Housing Corp., notes that if you found a dead animal in the house, you’d “get rid of it.” In the same way, a homeowner should know what is causing indoor air pollution, and either stop bringing it into the house or remove it when possible. Ventilation is an alternative strategy.

Specifically, a person could choose to stop using pesticides and cleaning supplies with harsh chemicals, eliminate scented personal care products, ensure that bathrooms and kitchens are properly vented to the outside so humidity doesn’t build up. “Basements and crawl spaces are often sources of mold problems,” Salares says, adding that homeowners should dehumidify in warm months, and noting that humidifiers should only be used in winter when “absolutely necessary”.

Changes for Healthy Home Air

Michele Chase today is a mother of three, and one daughter, Cara, is also asthmatic. She keeps them both under control with daily medication and by meticulously cleaning their home to avoid triggers. Chase washes bedding every couple of days, her curtains once a week and uses a dry mop on her hardwood floors daily. She shies away from pesticides, and any cleaning products with harsh chemicals.

The Clemens family certainly made radical changes to their home life. For the sake of their daughter’s health, they moved into a small townhouse, where they ripped out all carpets to avoid the allergens they would harbor, and replaced them with hard flooring. They put in a central air conditioner so they could keep the windows closed and the pollen out. Angela, now 6, has only had one asthma attack in the past three years.

Chase and Clemens are two who have gone to great lengths to manage their children’s health, with success. They illustrate the good news when it comes to indoor air pollution: if we are part of the problem, we can also be part of the solution.

*Child’s name changed for privacy.

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