By Amelia Glynn

We are what we breathe. And unfortunately, the air inside our homes isn’t always pretty.

The Environmental Protection Agency, which ranks poor indoor air quality among the top five environmental risks to public health, estimates that the air inside our homes is a whopping two to five times more polluted than the air outside. Multiplying this by the fact that we spend as much as 90 percent of our time indoors results in a slew of health problems, ranging from dizziness and nausea to allergic reactions, asthma and even cancer.

The good news is that there are many simple steps we can take to clean up our air and start breathing easier. Here are a few to consider:

Make fresh air your friend
Newer homes are designed to keep out the chill, but because many lack proper ventilation, they also work to trap in pollutants. In the case of air quality, what we can’t see can hurt us: the more microscopic the particles, the more damaging they can be to our health. These particles can build up over time, so it’s important to open the windows and let fresh air inside as often as possible — even in the heat of summer and cold of winter.

Heat your home more healthfully
According to the American Lung Association, more than 70 percent of Americans have forced or central air heating in their homes, yet nearly 50 percent don’t change the filter in their units regularly. And 10 percent have never replaced the filter.

It’s important to have your central heating system inspected every year and to change your filters once every three months.

Also, keep in mind that any fuel-burning appliance (ranges, ovens, water heaters, clothes dryers, fireplaces and grills) can be a potential source of carbon monoxide and nitrogen dioxide if they are not well vented or maintained.

Go green with household cleaners
Unless you are using products scented with natural oils, your favorite “clean smell” is likely the result of a chemical concoction. Try natural cleaning agents such as baking soda and white vinegar. Or look for brands with non-toxic ingredients like Shaklee’s Get Clean or Mrs. Meyers Clean Day. If you’re a fan of scented candles, consider switching to soy, which burns much cleaner than petroleum-based counterparts. To keep the bugs away, use boric-acid-based bait stations as an effective alternative to chemical sprays.

Enlist the power of plants
While formaldehyde (found in plywood, adhesives, carpets and paints), benzene (found in Styrofoam, plastics, lubricants, detergents and synthetic fibers) and carbon monoxide (off-gassed by heating or cooking equipment) are bad news for people, plants can thrive on them and help remove them from the air. Peace lily, bamboo palm, English ivy, mums and gerbera daisies top the clean-air list. Plus, they’re easy to care for, so even if you don’t have a green thumb, you’ll still have a good chance of keeping these babies alive.

Keep mold and mites at bay
To help prevent mold, make sure bathrooms and kitchens are well ventilated and use dehumidifiers in basements and garages (just remember to change water trays frequently). Wash bedding in hot water at least every 10 days to kill dust mites, and use a high-quality, HEPA (High Efficiency Particulate Air) filter vacuum (which won’t release fine dust particles back into the air).

Declare your home a shoe-free zone
According to the Environmental Protection Agency, up to 90 percent of most people’s exposure to pesticides occurs indoors. A lot of these and other toxic chemicals enter our homes through our shoes, so it’s best to check them at the door.

Shield yourself from secondhand smoke
Secondhand smoke contains as many as 4,000 chemicals, including 200 known poisons, such as formaldehyde and carbon monoxide, as well as 43 carcinogens. If you or your friends smoke, be sure to light up outside.

Put radon on your radar
An estimated one out of every 15 homes in the United States has radon levels above what the U.S. Environmental Protection Agency considers healthy. Radon, a naturally occurring radioactive gas found at high levels in every state in America, can seep into our homes through the surrounding soil. Indoor radon exposure is the second leading cause of lung cancer in our country after cigarette smoke.

Because this gas has no color or odor, it requires special detection kits. Inexpensive and easy to use, you can purchase one at your local hardware store. Or visit epa.gov/radon for more information.

Beware of off-gassing
Before you bring new furniture, drapes or carpeting, which usually contain formaldehyde (a colorless and pungent gas known to cause mild to severe eye, nose, skin and throat irritations), into your home, air them out in your garage or backyard for a few days. And be sure to open your windows and run exhaust fans for the first week following any remodeling projects. Or as an alternative, buy products and building materials made with green materials.

Researching this article opened freelance writer Amelia Glynn’s eyes, inspiring her to open the windows in her San Francisco flat more often.