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The Science of Health

Is there a monster under the bed?

Health Canada's own Christine Levesque storing house dust samples at the lab in Ottawa.

Health Canada's own Christine Levesque storing house dust samples at the lab in Ottawa.

The far corner under the bed may be one of the safest places in most homes for house dust to hang out. But still, it was not safe from Health Canada researchers who wanted to know what’s in dust anyway?

Curious about whether dust contains harmful chemicals that could build up over time, Health Canada launched the Canadian House Dust Study led by Dr. Pat Rasmussen, who sampled dust bunnies from over 1,000 homes in 13 cities across the country.

One of the first contaminants researchers looked at was lead. Lead is a highly toxic metal that is found naturally in the earth's crust. It is used to produce many consumer products (like pipes, cars, electronics and batteries). Lead was once used in products like paint and gas, but the Government of Canada now restricts its use in many products.

Everyone is exposed to low levels of lead through food, drinking water, air, dust, soil and some consumer products. But ongoing exposure to lead may be harmful to your health.

The results from the study provide us with a better understanding of the background levels of lead that Canadians may be exposed to in their homes. Health Canada has not yet set reference levels for lead in house dust, so the measurements are an important starting point for future research related to lead exposure in indoor environments.

All of the homes tested had some levels of lead that could be measured in their house dust, but most homes (90%) had normal levels for a typical city environment. Higher lead levels were mostly found in older homes, mainly because of the lead paint used when they were built.

The best way to reduce lead exposure in your home is to keep the dust bunnies away. The highest levels of lead were found in entryways, suggesting it’s tracked in from the outside.  So, use a damp mop or cloth to clean, and vacuum your doorways regularly to help prevent lead and other unwanted chemicals from getting too far into your home! Dusting, vacuuming and wet-mopping the rest of your house regularly will help keep dust levels down in your home.

We’re not done looking at dust. Now that the samples have been tested for lead, Health Canada researchers are looking for traces of other metals including zinc, cadmium and nickel and contaminants like sulphides, carbonates and organic carbon compounds.

This study attracted the attention of the curators at Montreal’s Canadian Centre for Architecture who decided to include some of Dr. Rasmussen’s work in their 2012 exhibition: Imperfect Health: The Medicalization of Architecture. The show examined the complexity of today’s interrelated and emerging health problems along with a variety of proposed architectural and urban solutions.

If you’re concerned about lead in your home, learn more about how to reduce your exposure to lead.

- Susan Demaray