I passed this last summer at a cabin in Maine. There I continued reviewing equipment for WIRED. I tested air purifiers, food dehydrators, and indoor air quality monitors. I tracked outdoor air quality, monitored indoor air, and watched the numbers increase in their predictable pattern when using the stove.
A couple of weeks into my cabin air quality experiment, I noticed strange spikes in PM 2.5 for seemingly no reason. PM 2.5 are those invisible particles that can enter the deepest parts of the lungs and then into the bloodstream. They contribute to negative health outcomes such as heart attacks, hypertension, and respiratory problems, to name a few. I hadn’t been cooking; I hadn’t done anything. PM 2.5 numbers, illuminated on several air quality monitors, increased from 4 to 24 to 75 or more. The internal sensors in my air purifiers, some of which use the same technology as my air quality monitors (a small chamber where a beam of light is scattered and collects particles, even the invisible PM 2.5), activated automatically your fans. And all I did was walk across the room.
It was the carpet!
The first time I heard about the dangers of carpets and rugs in the home was through air pollution researcher Shelly Miller at the University of Colorado at Boulder, whom I interviewed for my first article on air quality; that is, how to get good air in my 100-year-old apartment in Brooklyn. Miller was the one who introduced me to the term resuspension. Resuspension is exactly what it sounds like: dust and carpet particles take flight when your footsteps pick them up. The same thing happens with the upholstery. Sit on a couch and you might see a cloud of dust. I have an air quality monitor next to my bed and have seen an increase in PM 2.5 when I move my weighted blanket over my duvet. We dust, vacuum and wash fabrics not only for aesthetic reasons; It is also for our health and, more specifically, for our hearts.
Photography: Lisa Wood Shapiro
It’s in the cloud
I had forgotten about the resuspension and let my rule of not wearing shoes in the cabin slip. By the time I made the connection, I had taken both rugs outside to beat them the old-fashioned way with a broom. Gigantic columns of dust flew into the air. I had brought my six-year-old Dyson vacuum cleaner with a HEPA filter, but in the end I rolled up my rugs, put them away, and opted to sweep and mop the hardwood floors. Indoor air quality improved.
I contacted an indoor air quality researcher. Andrea Ferro from Clarkson University and asked how to clean the air from the scourge of carpet resuspension. He noted that HEPA air filters are up to the task: “We resuspend dust all the time. “It is a normal component of indoor air.” When I asked him how high the dust rises, he told me: “The resuspended dust easily reaches the height of breathing and mixes with the room air.” And it’s not just about being organized. There are health benefits: cardioprotective benefits that come with having good air.
When I first told Jonathan Newman, director of Clinical Research at the Center for Cardiovascular Disease Prevention at NYU Langone Health, about my poor indoor air, he mentioned a study He worked in public housing in New York City with the goal of quantifying the health benefits of good air. And indoor PM 2.5, resuspended or not, is something that HEPA filters can clean. Dr. Newman noted that air purifiers “appear to reduce blood pressure by approximately 3 to 4 mmHg at various time intervals.” And while reducing blood pressure by three points may seem like a small number, Dr. Newman offered insight into seeing it in terms of how we improve our health through diet. Reducing PM 2.5 indoors “also has to do with what we see with dietary approaches to lowering sodium and blood pressure.”