We spend 90 percent of our time indoors. We should worry more about what we are breathing there.
That's Tad Putyra, President of Great Gulf Low Rise, opening the Active House Symposium 2019 at the Evergreen Brickworks in Toronto. He is not the only presenter noting that people spend 90 percent of their time indoors, and that we should be thinking more about healthy indoor air.
We have biological contaminants, like fungi and bacteria, and chemical contaminants, such as gaseous pollutants and particulates. They cause irritation, coughing, asthma, worsening COPD, cancer, pulmonary hemorrhaging and premature mortality.
The first problem is the source control, keeping this stuff out in the first place. That means not using materials like vinyl that can release phthalates or composites made with formaldehyde.
Then there is the issue of what we bring in on our feet or generate just by moving around. It turns out that our bodies are moving buckets of particulates and bacteria. There actually is a thing called the "Pig Pen effect" after the Peanuts character. Who knew that two persons walking around was almost as bad as smoking a cigarette inside? Or that making a bed was so dangerous! Fortunately, I don't do that very often.
Finally, there is the question of particulates. We have been discussing this issue on TreeHugger for years, but every year the understanding of the danger of fine particulates (PM2.5) increases. It was lost in the haze of cigarette smoke, but now it is recognized that PM2.5 from other sources cause heart attacks, respiratory diseases, strokes, and cancer. It's clear that one should not light incense or candles in the house.
But it also seems totally obvious to me that every kitchen should have an exhaust hood vented to the outside; a recirculating hood might take out the grease, but it will not touch the PM2.5.
Sandra Dedesko's presentation was a real wake-up call. Reading the Active House specifications, I am not convinced that they really go far enough, measuring only CO2, which they call "a good indicator of the amount of bio-effluents, pollutants from humans, in the air." They imply that natural ventilation can do much of the job, but I suspect in cities these days, every home needs serious filters to keep out the PM2.5 floating around from fireplaces, pizza joints and car tires.
But then I am not certain that there is any standard or any regulation that goes far enough about interior air pollution. After seeing Sandra Dedesko's presentation, I believe we should all be looking more closely at the issue.