If you’re one of the many people spending a lot more time at home these days, spare a thought for the air you’re breathing there.
Compared to other indoor settings, many homes have few “air changes per hour,” a metric engineers use to assess ventilation, according to the US Environmental Protection Agency (EPA). As a result, air pollutants can pile up. These can include fine particulate matter (also known as PM2.5), carbon monoxide, ozone, radon, volatile organic compounds (VOCs), biological contaminants (pet dander or dust mites, for example), and more. Poor indoor air quality has been linked to health effects including headaches, fatigue, heart disease, and cancer. Children, the elderly, and people with cardiovascular or respiratory health issues are most at risk.
“Since more [people] than ever are working from home, I do believe it’s essential to be proactive about the quality of our indoor air,” said Neeta Ogden, a New Jersey-based immunologist and allergist. “Often people aren’t even conscious of their indoor air environment and how they might improve it.”
Here are a few things you can do to make your home a nicer place to breathe.
Signs of poor indoor air quality include buildups of dust, moisture condensation on windows, and stuffy or smelly air. Typical sources include gas stovetops, heating and cooling systems, mold, pets, insulation containing asbestos, new flooring or carpentry, household cleaning chemicals, and some pressed-wood furniture. If you want to directly measure your home’s air quality, digital monitors are available for $100-200.
In a March study, public health researchers at Harvard measured fine particulate matter in the air of 72 Boston-area households, representing a range of income levels. On average, 77% of particles were found to originate from sources inside the building—stovetops and cigarettes were chief culprits—rather than outdoor sources like pollen or pesticides.
So the first step to improving air quality is to increase circulation: Open the windows and run a fan. In addition, Ogden said, it’s important to avoid clutter because it offers particles places to collect. Wipe down surfaces daily, particularly those where you spend a lot of time, like a desk or bedside table, to get rid of particles you might inhale. A simple mix of water and vinegar is fine, she said.
Mold is particularly an issue in humid environments, she said. “Once mold starts growing, spores can easily be aerosolized into your indoor airspace, so keep a fan on in the bathroom, fix leaks, and don’t run your shower for long periods before getting in.”
Every person’s sensitivities will be different. If you’re experiencing discomfort that you think may be associated with poor indoor air quality, Ogden recommends washing your eyes and nose with saline solution before bed. You may need to consult with an allergist or immunologist about which sources of indoor air pollution could be most problematic for you, and whether you could be a candidate for allergy shots to mitigate the effects of any unavoidable sources.
Avoid introducing pollutants from outside into your home. Don’t track dust or dirt into the house on your shoes, especially in springtime and summer when pollen is prevalent. Brush down pets outside, and keep screens in any open windows. Indoor plants can also be sources of mold; consider moving some outside. Weatherization (installing storm windows, weather stripping, or caulking, for example) is a double-edged sword, EPA warns: It tends to improve insulation and reduce the use of heating and cooling, but can also increase the concentration of indoor pollutants because it reduces air flow with the outside.
One particularly dangerous outdoor pollutant is radon, a colorless and odorless gas that leaks into homes from the soil through the foundation. One in 15 US homes has elevated levels of radon, according to the EPA, and radon pollution is the country’s second-leading cause of lung cancer. If you’re buying a new home, be sure to have it tested for radon. Many private contractors offer radon testing and can install special filters and other protective retrofits.
Smoke from candles, incense, cigarettes, and cannabis leaves behind pollutants and particulate matter that can then be inhaled, so air out rooms after burning anything in them and promptly dispose of ash. The same goes for chemical air fresheners, many of which contain VOCs and formaldehyde, can also leave behind particulate matter.
The Harvard study, which found pollution from gas stoves to be worse in multifamily buildings, was only the latest evidence of the health risks of gas stoves. They’ve been linked to elevated rates of childhood asthma and other respiratory disease, and greater risk of complications from Covid-19. Electric stoves are also better for the climate because they eliminate a source of greenhouse gas emissions from natural gas, a fossil fuel. But the gas industry has lobbied hard against US state efforts to mandate electrification in new buildings. If you have to have gas—because you prefer it for cooking or don’t get to choose your stove—make sure the stove is professionally adjusted to prevent leaks and maximize its efficiency.
Filters in air conditioning systems should be replaced regularly. A good vacuum is essential for capturing dust and dander, especially if you have a pet. Ogden recommends “a good air purifier with a HEPA filter that can capture up to 99.97% of airborne particles from the air,” and a humidifier during drier months: “Moisture in our air is essential to a healthy respiratory system and fending off the dryness that comes with congestion and allergies.”