How to Protect Yourself From Indoor Air Pollution at Home

What they are: VOCs, or volatile organic compounds, are gases emitted from paints, cleaning products, refrigerants, pesticides, personal care products, air fresheners, building materials, and more. “A lot of the chemicals used in things like couches and carpets in the home” emit VOCs and less volatile semi-VOCs, Corsi says. They can irritate your throat, nose, and eyes; cause headaches, dizziness, and nausea; and even damage internal organs. Certain VOCs, such as benzene and formaldehyde, are known human carcinogens. 

Unsaturated VOCs, like terpenes and terpene alcohols found in air fresheners, are “highly reactive with any ozone that is present in an indoor space and the associated chemistry can lead to a wide range of oxygen-containing byproducts (gases) as well as ultrafine particles (nanoparticles) that can be inhaled,” Corsi adds.

Where they hide: VOCs can be harmful not only when they’re breathed in as gases but also, in some cases, when they’re adsorbed and absorbed into particles of house dust and are depos­ited on a floor or surface, Corsi tells us. “When that dust becomes disturbed and airborne, you can inhale it.”

Who’s at risk: People who have new furniture in their homes or who use harsh chemical cleaners.

How to find and fix them: First, reconsider some of the harsh chemicals, such as those found in glass and floor cleaners, that you use in your home. How many are truly necessary? When you do need to use them, open the windows. Consider buying mattresses and furnishings that use natural fibers and fillings, such as cotton down, when you can. Look for ways to reduce your use of pesticides inside and outdoors.

Additionally, control dust using a vacuum cleaner, an air purifier, or both, with a HEPA filter. That’s especially important if a pregnant person or young children are in the home; both are at risk for problems from VOCs. Another option: Use a damp mop on hard surfaces to prevent agitating the dust.

What it is: A microscopic fungus that lives both outdoors and in, mold spreads via tiny airborne spores that can grow on almost any damp surface. Over a thousand types have been found in U.S. homes, according to the nonprofit National Center for Healthy Housing. Some mold (and mildew, another type of fungus) can cause skin rashes, flu-like symptoms, eye and lung irritation, and other health problems.

Where it hides: Mold is most commonly found in damp areas of your home, such as the bathroom, kitchen, and basement. But it can also thrive under and in carpets or rugs, above ceilings, and in walls, cabinets, crawl spaces, attics, and any room where excessive moisture persists.

Mold can also contaminate your home’s air ducts, letting spores spread throughout your home every time the heating or air conditioning system operates. Homes can be especially susceptible to mold after catastrophic weather events, such as hurricanes, floods, or deep freezes, which cause pipes to burst.

Who’s at risk: People whose homes are damp because of high humidity, poor ventilation, a leaky roof or basement, or damage from flooding.

How to find and fix it: Many mold problems can be seen with the naked eye, and many can be detected by their telltale musty odor. If you suspect mold but can’t see it, test for it. (Test kits are available at hardware stores and online.)

To mitigate mold, first find and fix the source of moisture, whether it’s a leaky roof, a poorly ventilated bathroom, or another problem. Then take steps to remove the mold by using water, detergent, or a disinfectant such as a diluted bleach solution, or by throwing away the mold-covered object.

The EPA recommends doing the job yourself if the mold-contaminated area is less than 10 square feet in size. Use protective equipment, such as an N95 mask, goggles, and gloves, to ensure your safety. (For more, see the EPA’s “A Brief Guide to Mold, Moisture and Your Home.”) Larger-scale problems may require professional remediation.

To prevent mold from returning, reduce your indoor humidity to between 30 and 60 percent via better ventilation and dehumidifiers, if necessary.

You might be eligible for financial assistance from the federal government if your mold problem is the result of a recent weather disaster. For more information, visit the Disaster Assistance Improvement Program website.

What it is: A naturally occurring mineral fiber that’s corrosion- and heat-resistant, asbestos has been used for decades in a range of home products, from the insulation around heating ducts in basements to the asphalt tiles on roofs. Inhaling these tiny fibers, which can be 1/500 the width of a human hair, can trigger mesothelioma, a type of cancer, and the lung disease asbestosis. Symptoms frequently emerge decades after exposure. Because of these risks, asbestos is used far less often now than in the past. But it’s still thought to contribute to between 12,000 and 15,000 deaths each year in the U.S., according to an analysis by the Environmental Working Group Action Fund, a social welfare organization.

Where it hides: If your house or apartment was built in or before the 1970s, there’s a good chance that certain building materials contain asbestos because insulation frequently contained it. Some textured “popcorn” ceilings also contain asbestos, as do some hot water and steam pipe coatings, roofing and siding shingles, and the backing of some vinyl sheet flooring.

Who’s at risk: People with homes built before about 1980 who are remodeling or renovating after damage.

How to find and fix it: Asbestos in your home is generally a concern only if the material gets disturbed. So look for it if you are considering renovations that might disturb the material, or if the material was damaged, which can cause it to shed fibers. In such situations, hire a professional: Unless a material is labeled, you can’t tell by looking if it contains asbestos, and handling the material could dislodge fibers. If tests confirm asbestos, it should be sealed, covered, or removed by an asbestos abatement professional. You can often find licensed experts through your state’s health department.

What it is: Radon is a radioactive gas that’s emitted from soil, water, and rocks and seeps into homes. Almost 1 in 15 U.S. homes has a level that should be reduced, according to the EPA. Radon is deadly. It’s the second leading cause of lung cancer after smoking, causing 21,000 cancer deaths a year in the U.S.

Where it hides: The gas enters homes via cracks, holes, sumps, drains, and sometimes well water. It is found in every state, but some parts of the U.S. are more susceptible than others. (See the EPA’s map.)

Who’s at risk: People who have not had their home tested for radon and those who haven’t taken steps to reduce levels after a positive test.

How to find and fix it: The gas is colorless and odorless, but still relatively easy to identify, says Joseph Allen, director of the Harvard Healthy Buildings Program in Boston. Everyone should test their home at least once.

“The classic method of measuring is a charcoal test kit you can get online or in a store, but there are newer, low-cost sensors that measure radon in real-time,” Allen says. He explains that the classic tests measure radon levels over a 48-hour window, but the newer devices—which used to cost thousands of dollars but now cost only a few hundred—allow you to see minute-by-minute fluctuations over weeks and months. Allen recommends using a model from AirThings. 

Levels of 4 picocuries or more per liter are the limit, Allen says, while 2 to 4 pCi/L is the range you want to take action. Depending on your home’s foundation type, that may involve hiring a certified contractor to seal cracks and openings, insert a pipe through the floor slab, and vent the gas out. Retest a month after the work is completed.

Mitigation can cost from $780 to $1,200, according to HomeAdvisor. Buying a home? Get it tested for radon and negotiate mitigation costs before sealing the deal. Some states and municipalities offer financial help for lower-income residents; contact your local health department for more information.

What it is: This is an odorless and colorless gas produced when wood, charcoal, or any fossil fuel, such as heating oil, propane, or natural gas, is burned. Exposure to elevated levels of CO can make your blood unable to carry enough oxygen to survive. Symptoms include headaches, nausea, sleepiness, confusion, and shortness of breath. More than 400 people die in the U.S. each year from accidental exposure to the gas, according to the Centers for Disease Control and Prevention.

Where it hides: Most appliances in the home that burn oil or gas, such as stoves and furnaces, are designed to minimize the risk from CO. But a malfunction—a blocked vent or chimney, for example—can quickly turn dangerous. And appliances such as generators and charcoal grills, which are meant for outdoor use, can become killers when used indoors, even in a garage.

Who’s at risk: People with malfunctioning stoves, furnaces, or other major appliances that use gas, propane, or heating oil, and those who don’t have or use exhaust fans with gas stoves. Using a generator indoors or too close to your home can be exceptionally dangerous, as it produces high levels of carbon monoxide.

How to find and fix it: Install a CO detector on every level of your home and outside every sleep area, such as in a nearby hall. Test the devices regularly. Combination smoke and CO detectors are also available.

For the best protection, have a professional electrician install interconnected detectors in your home so that when one sounds, they all do. If your heating system and hot water tanks are powered by gas or oil, have them checked for CO leakage and maintained each year. Also, have them checked for adequate ventilation. Never heat your home using your gas range, and never use a camp stove or generator indoors.

What it is: Small amounts of lead, a heavy metal, occur naturally in soil, air, and water, and in the past, it was widely used in paint and plumbing supplies. “Lead is one of those dangerous legacy hazards,” Allen says. “It’s one of the most potent neurotoxins we know of, and exposure to it in kids is associated with lower IQ, nerve and developmental issues, and behavioral problems.” Pregnant women could miscarry or deliver prematurely if exposed.

Where it hides: Homes built or renovated between 1960 and 1978, when lead paint was banned in the U.S., have an almost 1 in 4 chance of having lead-containing paint. (Odds are even higher in pre-1960 homes.) Deteriorating paint creates dust that can be inhaled. Children can ingest lead paint by chewing on an exposed surface. The heavy metal can also be found in the soil near your home. It can enter your water when metal fixtures and pipes made before 1986 corrode.

Who’s at risk: People who live in communities served by lead water pipes or in homes built before 1986, and people whose homes were painted before 1978.

How to find and fix it: If your home was built or renovated before 1978, test the paint for lead, especially if you have young children in the home. The 3M LeadCheck and D-Lead kits work on wood, drywall, plaster, steel, and iron. However, according to the EPA, it’s best to hire a professional, and a pro is necessary to test other surfaces, such as stucco. To reduce the risk of lead paint, consider encapsulation—painting over it with a special primer that seals the lead in place. That’s cheaper than complete removal and does not create chips, flakes, or dust. If you want it removed instead, hire a professional and expect to pay between $3 and $10 per square foot.

Checking for lead in water is essential if your home was built before 1986 and you have young children living in it. But some communities still have lead in pipes leading to homes, so everyone should consider testing. Home tests might not be accurate, so the EPA recommends using a certified lab. Ask your utility whether it offers free lead tests. Or check Healthy Babies Bright Futures’ Lead in Drinking Water program. The organization offers low-cost lead tests. Many water filters can remove heavy metals.