*A note about this column which appears in The Toronto Sun and in other Sun Media newspapers this weekend. I’ve received quite a few emails already asking about certain plants that appeared with the column in various cities. Sadly, I can’t identify them nor can I even see that particular version of my column! Not only do I not know when or where across the country my columns appear, unless someone writes and tells me, photos are chosen locally. In Toronto, they decided to use a picture of people suffering from allergies. Having said that, I truly enjoy the feedback about House Proud.
In his joke about harsh Canadian winters, Jon Stewart speculates that Canadians and Americans looked at a map of North America and our forefathers, being so stereo-typically polite said, “We’ll take the frozen part.”
The winter of 2013 has brought us some pretty frosty temperatures even in parts of the country where windchills of -30C aren’t typical. Authorities advise us to keep children, pets and ourselves inside as much as possible during these spells and we’re only too happy to oblige. But what are we breathing in during a few days of hibernation with doors and windows locked tightly? You can probably tell when the air gets stale but what about the things you can’t see or smell?
Dr. James Scott, Associate Professor at the University Toronto and an air quality specialist says it’s not your imagination if you notice the air is different when you’re sequestered during bad weather.
”We tend to spend more time indoors and also our homes tend to lack the same level of natural ventilation they do in the summer. These factors may increase our exposure to certain indoor air contaminants, where present, like carbon monoxide, formaldehyde, ozone, radon and volatile organic materials. We also know that reduced natural ventilation may help to increase the impact of some infectious diseases.”
Some people say their houseplants are working as natural air filters. NASA studied some common indoor plants with an eye to keeping the air as breathable as possible on space stations. The spider plant was shown to reduce airborne levels of formaldehyde. The philodendron, Devil’s Ivy and chrysanthemum also worked on benzene, ammonia and other substances with virtually unpronounceable names.
But it might not be wise for everyone to fill their front room with a row of potted mums. Dr. Scott agrees that several plants have proven to be beneficial but there’s also a potential problem and the trade-off could be itchy, watery eyes and sneezing.
“Plants have the downside of increasing the indoor levels of fungal and mite allergens. So in some cases, using plants to help “clean your air” can have the unintended effect of replacing one group of contaminants with another.”
That takes us to the manmade, filtered air purifiers where we’re told we can improve our surroundings for a few dollars or a few hundred dollars. Dr. Scott says some of these machines can help but they’re not all created equal.
“Filtered air purifiers can be very useful in reducing allergen burden for people who suffer from allergies. They only work for particles and so are not helpful in removing chemical contaminants. Likewise, they function best when they are used as part of a more integrative strategy that includes other efforts, such as removing or reducing contaminants, properly adjusting indoor temperature and relative humidity.”
The scientific jury is still out on some other models of air-cleaning machines.
“There is some evidence that air purifiers that use UV light help to reduce the levels of pathogenic organisms in the air, but unless they also have filters, they are not effective in removing allergenic particles. The effectiveness of other air purifying technologies, such as ion generators, remains unclear. Air purifiers that use ozone are dangerous and should never be used.”
In most cases these contaminants appear to be more of a nuisance than a threat but we still want to breathe the cleanest air possible. You can buy detectors for some gases like radon and even have a professional test your home’s air quality. The Canadian Lung Association’s website (www.lung.ca) lists some of the most common causes of unwanted airborne contaminants and what to do about them. It’s good reading on one of those cold, winter days indoors when you’ve run out of things to do.