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Do You Really Need An Air Purifier In Your Home? We Asked An Expert

Emma Loewe
July 14, 2019
Emma Loewe
mbg Sustainability + Health Director
By Emma Loewe
mbg Sustainability + Health Director
Emma Loewe is the Senior Sustainability Editor at mindbodygreen and the author of "Return to Nature: The New Science of How Natural Landscapes Restore Us."
Image by Trinette Reed / Stocksy
July 14, 2019

We do approximately a million and one things in our homes, and a lot of them consistently ding our air quality. Cooking on the stovetop, doing laundry, using conventional cleaning products, burning candles—it all adds up to indoor air that is, depending on where you live, more polluted1 than the air outside.

Toxic chemicals can cause physical irritation (think itchy throat, watery eyes, and headaches) in some people but not others, which can make it hard to pinpoint how clean or dirty your air actually is. 

What kind of air pollutants should I be concerned about? What can I do to keep them out of my home? Do I need to buy an expensive air filter for every room? Here at mbg, we field these questions a lot—and wonder about them ourselves!—so I took the liberty of reaching out to an expert for some answers. 

Shelly Miller, Ph.D., is a professor in the Environmental Engineering Program at University of Colorado Boulder who specializes in air pollution and is currently researching the relationship between respiratory health and the home environment. Here, she breaks down what you need to know to breathe easier.

On the top pollutants of concern at home.

Miller says there are a few classes of chemicals to watch out for at home:

  1. Combustion pollutants that occur when we're cooking—one of the main ones being particulate matter. When cooking with natural gas, you also get nitrogen dioxide, which is a respiratory irritant.
  2. VOCs, volatile organic compounds, which also come from cooking, as well as cleaning and personal care products.
  3. Flame retardants, which you'll find in some furniture and textiles.
  4. Phthalates in some plastics and personal care products.
  5. Pollutants that enter from the outside2 such as ozone, sulfur dioxide, nitrogen oxide, and particulate matter.

On how to keep them in check.

"The way we get rid of these pollutants in the typical home is through ventilation—meaning you exchange the inside air with outdoor air," Miller says. Unless you live in a polluted urban area or near a major roadway (more on that below), you should open your windows when it's nice out to facilitate airflow.

Her top tips for maintaining clean air at home include using a welcome mat and taking shoes off at the door, dusting often, ditching unnecessary carpeting, and running your exhaust hood every time you cook. If you have the option, choose a ducted hood that carries air out of the home over a ductless one that just recirculates the air.

When it's time to get a filter.

There are three camps of people Miller says should consider investing in an air filter:

  1. If you live in a highly polluted city (Los Angeles and Houston were two she named in the U.S.), on a busy street, or anywhere you may be exposed to traffic-related air pollution when you open up your windows for hours at a time.
  2. If your area is prone to wildfires.
  3. If you are respiratory sensitive or have asthma. If you often cough a lot, have itchy eyes, or get headaches in your house that usually fade when you leave, that's a telltale sign you might need one too.

On what to look for when you're buying a filter.

"I recommend sticking with the tried-and-true technology, which is a fiber filter, like a HEPA filter," Miller says. While HEPA filters can be pricey, you don't necessarily need a 'true' HEPA, one that captures 99.9+%, of particles, and can settle for a less expensive one that captures 95%. (Just make sure it's set to "recirculation" mode.)

"If you live in a polluted city, you'll want to filter out ozone, nitrogen oxide, and VOCs and get one that also has activated carbon," she adds. "It's an added filter that can remove gas-based pollutants." As for which HEPA filters are the most effective, she trusts ones that are certified by AHAM, a consumer database that does rigorous testing on hundreds of models and reports on how well they filters smoke, dust, and allergens. It also reports on how many square feet each filter cleans at a time to help you decide how to best cover all the highly trafficked areas in your space.

Emma Loewe author page.
Emma Loewe
mbg Sustainability + Health Director

Emma Loewe is the Sustainability and Health Director at mindbodygreen and the author of Return to Nature: The New Science of How Natural Landscapes Restore Us. She is also the co-author of The Spirit Almanac: A Modern Guide To Ancient Self Care, which she wrote alongside Lindsay Kellner.

Emma received her B.A. in Environmental Science & Policy with a specialty in environmental communications from Duke University. In addition to penning over 1,000 mbg articles on topics from the water crisis in California to the rise of urban beekeeping, her work has appeared on Grist, Bloomberg News, Bustle, and Forbes. She's spoken about the intersection of self-care and sustainability on podcasts and live events alongside environmental thought leaders like Marci Zaroff, Gay Browne, and Summer Rayne Oakes.