Indoor air can be two to five times more polluted than outdoor air, and, in some cases, pollution levels can be 100 times higher inside, according to the Environmental Protection Agency. Given that people in the United States spend roughly 90 percent of their time indoors, it’s important to keep the air in our homes as safe as possible. Depending on the particles and gasses involved, indoor air pollutants can have health effects that range from eye irritation, headaches, and fatigue to respiratory disease, heart disease, and cancer.
What causes poor indoor air quality in the first place? Outdoor pollution, such as particulates from vehicle exhaust or wildfire smoke, can enter through ventilation systems, open windows and doors, and cracked weatherstripping and become trapped inside. However, the majority of indoor air pollutants are released within the home, including allergens such as mold and pet dander; gases and particulates from burning gas or wood, cooking, and smoking; and volatile organic compounds—a large group of chemicals that can end up in the air—from household cleaners, building materials, and furniture.
While it’s tempting to add an air purifier to your shopping cart immediately, they are less effective than you may expect. “Most of those smaller units have so little air being cleaned per [minute], it just doesn’t lead to a change that’s measurable indoors,” says Lynn Hildemann, chair of the Department of Civil and Environmental Engineering at Stanford University. Instead, here’s how to actually improve your indoor air quality.
Let in fresh air.
When the air quality outside is good, one of the best ways to improve the air inside is to open the windows, which can remove or dilute indoor-emitted pollutants. You can check your local outdoor air quality at AirNow.gov, which uses hourly local monitor readings to report pollution levels across the United States. A reading of 50 or below means that outdoor air pollution poses little to no health risk.