What is indoor air pollution and what can you do about it? Indoor air quality can be worse than outdoor. So learn what to do about air pollutants. According to the Environmental Protection Agency (EPA), indoor pollution levels can be two to five times greater than outdoor levels. Given that the average American spends up to 90% of their time inside, indoor air quality is a public health concern. What Affects Indoor Air Quality? Elliott Horner, PhD, principal scientist at UL Environment explains, "Indoor pollutants can be grouped into three different categories: gaseous, particulate, and biological." And, Horner adds, each category has its own risks. Breaking Down Those Three Types of Pollutants 1. Gaseous Indoor Pollutants When pollutants are in the gaseous state, they produce dangerous side effects. Minor ailments can include headaches and eye irritations. The pollutants can also trigger much more serious consequences, such as cancer and even death. The most worrisome gaseous pollutants include: Volatile organic compounds (VOCs) - Building materials and other household goods emit these chemicals, such as formaldehyde. Common sources are wood, drywall, adhesives, paint, cleaning products, furniture, and even home electronics. Radon gas - Occurring naturally in the soil, radon gas is the second leading cause of lung cancer, and it’s responsible for between 15,000 and 22,000 deaths a year, according to the National Cancer Institute. Learn about testing your home for radon gas . Carbon monoxide gas - A clear and odorless gas that is both naturally occurring and a byproduct of man-made combustion. Learn how to monitor and prevent exposure to carbon monoxide gas . 2. Particulate Indoor Pollutants Ultra-fine liquid or solid particles in the air can get deep into the lungs. They are associated with an increased risk of allergies and asthma attacks. Common particulates are: pollen dust dust mites animal dander diesel exhaust particles that seep in from outdoors secondhand smoke 3. Biological Indoor Pollutants 'Biological pollutants almost always involve dampness or water damage,' Horner says. Humidity, water-line breaks, and flooding are frequent sources. They can cause infections and worsen allergies and asthma, and often produce less-toxic VOCs that still are a cause for concern. Biological pollutants include: mold mildew bacteria - mostly occupant related viruses - all occupant related Maintain a healthy range and clear the air by reducing and controlling humidity at home with some simple tips. Detecting a Problem You can see many particulate pollutants, such as dust, but detecting the other types requires testing. 'There are several analytical sciences to detect issues in air quality, but they are very expensive,' says Horner. "However, there are some clues that the average person can pick up on, too." Horner suggests paying attention to foul or musty odors or eye, skin, or respiratory irritations among family members. Commercially available test kits can help you identify potential problems. If you suspect you're dealing with a bigger problem, contact an environmental consultant or your local or state health department for assistance. 9 Tips for Better Indoor Air Quality Air pollution isn't limited to the outdoors. Moisture, odors, gases, dust, and a host of other irritants can affect air quality indoors, too. Try these tactics to help freshen your home's air so you and your family can breathe easy. Open windows - Most heating and cooling systems recirculate inside air. When weather permits, give your system a break and let in fresh air. Open windows and place fans strategically to help direct fresh air through. Run exhaust fans - Turn on the kitchen fan to vent cooking pollutants, and the bathroom fan to curb mold-promoting wetness and fumes from cleaning products. Leave the fan running for about 45 minutes. Use doormats - They help prevent dirt and other outdoor pollutants from making it inside. Get two natural-fiber mats, one for inside and the other for outside your main entrance. Keep a shoe-free home too. Test for radon - DIY test kits, available online and at your local home improvement store, are inexpensive and easy to use. Don't mask odors - Scented candles and sprays can irritate lungs. Find the source of the smell, get rid of it, then ventilate well until it's gone. Use a dehumidifier - Stay under 50 percent humidity to keep mold growth at bay. Clean your dehumidifier regularly so it doesn't switch from humidity-reducing friend to mold-harboring foe. Vacuum regularly - You'll reduce the amount of dust and other pollutants released when you walk around. Invest in a quality vacuum with a HEPA (high-efficiency particulate air) filter, especially good at trapping even tiny bits of dust and dirt. Take it outside - Painting, sanding, gluing - anything that generates particles, gases or other pollutants - should be done outside. If outside isn't an option, open a nearby window and add a fan blowing air out. Clean up after your project quickly and well. Monitor your air quality - Devices can monitor temperature and humidity to help you understand how your home might affect your health.