We spend more time indoors than earlier generations did. Modern sealed homes keep drafts out. That means they keep air pollutants in. Indoor air can be more polluted than outdoor air. So how can we improve indoor air quality?

Many people have trouble with volatile organic compounds. These can come from new furniture, fresh paint, or even cleaning supplies.

If you use bleach to clean, for example, the fumes stink. They’re telling your nose that they’re toxic. But in a sealed home, they never go away. They just disperse throughout the house. They don’t stink anymore, but they still pollute the air.

The easiest way to keep fumes from cleaning products out of your indoor air is to use something else instead. Don’t use bleach indoors.

We can smell some indoor air problems, but not all of them. The problems we can’t smell include pet dander, mold spores, and dust mites that cause allergies. These wreak the most havoc in the winter when it’s too cold to keep windows open. But even in cold weather, it’s good to open them for a little while to allow fresh air in.

Here are some simple steps to improving indoor air quality.

Keep your home clean

It pains me to write this, looking around my office, but clutter traps and holds dust. From a health standpoint, we don’t clean to make the place look good but to get rid of as many air quality problems as possible.

So vacuum carpets and area rugs at least once a week. Your vacuum cleaner ought to have a HEPA filter to keep from blowing allergens back into the room.

Hard-surface floors don’t hold onto as many allergens as carpets and rugs. I’m not saying not to clean them, of course. Mopping removes more dust. But if you have problems with allergies, getting rid of wall-to-wall carpeting may help.

Regularly dust hard surfaces, such as end tables or dressers. And don’t neglect places not easily visible. I heard of a small boy that asked if it’s true that we come from dust and return to dust. When his Mom said yes, he solemnly warned her that someone was either coming or going under his bed.

Also, regularly vacuum upholstery and clean bedding, curtains, and anything else likely to collect allergens.

Use floor mats by every door. People can track in all kinds of potential pollutants, including various chemicals. A mat can keep them from tracking in as much or spreading it as far. To be as safe as possible, have people remove their shoes right away before they go farther into the house.

The less dust and other allergens, the better your indoor air quality.

Do you still have lead paint?

Lead interior house paint has been banned since 1978. But if you have an older home, it still may have lead paint undercoats of newer paint. Keep an eye on it.

If it starts to crack or peel, it can lead to lead poisoning. Babies can pick up good-sized flakes and get really sick. But the real problem for indoor air quality comes from lead dust. Everyone breathes it.

Getting the lead out of your house (or asbestos for that matter) is a costly headache. On the other hand, it will be less expensive to take care of it than medical bills and lingering health effects.

Ventilate for good indoor air quality

Most heating systems don’t directly let outdoor air in. Recirculating the same air can make it stale.

Even the best-sealed homes allow infiltration of outdoor air through joints and cracks in walls or ceilings. If you run an exhaust fan in your kitchen, bathroom, or attic, fresh air has to replace it from somewhere.

Mostly, however, you ventilate by opening windows and doors. It’s hard to keep windows and doors open in the winter when it’s cold outside, but on days when everyone stays home, at least open the door some. If you have a dog or cat that wants to go out and come back in, that’s probably enough.

In the summertime, some places have ozone air alerts. During those times, or in neighborhoods with a lot of traffic, you want to be sure not to let in outdoor air pollutants. Outside air improves indoor air quality only if it’s good, fresh air. So you may have to plan to open the windows only during certain times of the day.

Early morning or late evening will probably be the best times.

When it’s rainy out, the rain probably takes most pollutants out of the air and into the ground or storm sewer. It’s probably cooler out while it’s raining, too. So that might be a good time to turn off the air conditioner and open the windows for a while.

House plants

Houseplants do wonders for indoor air quality.  For one thing, they absorb carbon dioxide and release oxygen. Not only that, at least some of them remove many toxic air pollutants. Some seem to specialize in one pollutant or another.

Follow that link in the previous paragraph for a list of 19 houseplants tested by NASA. They are proven effective in improving indoor air quality. With some searching, you can probably find more. None of the ones NASA tested removed tobacco smoke, by the way. But some of them worked well against such toxins as formaldehyde, ammonia, and carbon monoxide.

One word of caution, however. Be sure not to overwater them.  Otherwise, mold can thrive in the soil. And the mold can trigger allergies. For people with severe mold allergies, houseplants can cause more problems than they solve.

Change filters to keep indoor air quality good

If you have a forced warm air heating system, you need to change the filters regularly. And get good ones that filter out small things like bacteria.

I do have one warning, though. I used to get the kind that filters out as much as  possible. The people who came to inspect my furnace finally persuaded be to get the second best. The ones I had were partly blocking the flow of air back to the furnace.

Now, viruses don’t get caught in the filter anymore, but I don’t get any flack from the furnace inspectors. And the filters still catch most of what would make bad indoor air quality.

Consider an air purifier

If you have severe allergy problems, you may not be able to find the source of your triggers. Or you might know and love the dog or cat that’s to blame. In that case, an air purifier—especially an ionic air purifier—can help.

Put it (or them) in the places where you spend the most time. They probably won’t get rid of everything, but they might cut down enough to make you more comfortable in your home.

Keep a healthy level of humidity

The relative humidity in your home should be between 30% and 50%. That probably means that you have to boost humidity in the winter and reduce it in the summer.

Mold and dust mites love moisture. You don’t want to make them happy. Running air conditioning dehumidifies the air.

Some especially moisture-prone places, such as the basement, might need an extra dehumidifier. .

Overwatering houseplants can all contribute to mold buildup.

Do you smoke?

Stop.

Or at least do it outside. Your furnace filter will trap whatever smoke gets that far, but smoke accumulates on other surfaces, too.

Lose the air fresheners

You can find all kinds of sweet-smelling products to give your home a fresh scent. They do it with volatile organic compounds.

They can spew dozens of chemicals into your air, whether solid,  oil, plug-in, or spray. Most are petrochemicals. And you won’t read what they are on product labels.

Tests of one plug-in air freshener found twenty different volatile organic compounds. Seven of them are regulated as hazardous or toxic. But the law only requires labeling as “fragrance.”

While you’re looking for ways to cut down on chemicals and improve indoor air quality, don’t forget “fragrance” in laundry detergent, dryer sheets, or other products. Prefer fragrance-free products. Stop using any aerosol sprays.

Check for radon

Radon is a radioactive gas that occurs naturally in soil. Indoor air pressure is usually less than the air pressure in soil. This difference in pressure can make your home act like a vacuum cleaner for radon. Probably all homes have some radon in them. Some homes have dangerous levels in it. Radon is a leading cause of lung cancer, second only to tobacco smoke.

Radon enters a house mostly through soil. If you have a basement or any part of your home below ground, it probably has a greater concentration of radon than the rest of the house. Well water can have high concentrations of radon. So if you use it for showering, it can release radon.

Since radon is colorless and odorless, you have to test for it. You can buy a radon detection kit or hire a contractor. In either case, the test ought to monitor the house for at least three months and look at various places in the house.

Many companies claim that their air purifiers reduce radon. Consumer Reports flatly says that they don’t. If you discover a radon problem, you’ll need to hire a contractor to install a system to take care of it.

Sources:

11 Easy Tips to Improve the Indoor Air Quality in Your Home / Jessica Miley, Interesting Engineering. February 28, 2018
Breathe easy: 5 ways to improve indoor air quality / Jeanie Lerche Davis. WebMD archives
Consumer’s guide to radon reduction / US Environmental Protection Agency. The link goes to an easier-to-read version at Rutgers University.
Easy ways you can improve indoor air quality / Harvard Health Publishing. March 2018