Healthy indoor environments provide an important foundation for good health. On average, Americans spend about 90 percent of their time indoors, where pollutant levels are often higher than those outside.

Even clean homes can cause human health problems due to the way they were constructed or the presence of certain household products. Health threats in homes can include toxic materials, like asbestos or lead; poisonous gases, like carbon monoxide or radon; and asthma- and allergy-causing conditions, like mold or dust mites.

Lead and asbestos can be a concern in older homes that were painted with lead paint or constructed using materials containing asbestos. Poor indoor air quality or mold in a home can cause allergies and respiratory illnesses. Radon, a cancer-causing gas that forms naturally in rocks or soil, can contaminate indoor environments through cracks in a home’s foundation; and the burning of oil, natural gas, kerosene, or other fuels can release poisonous contaminants, like carbon monoxide.

Fortunately, there are many things that can be done to improve the indoor environments of our homes and other buildings. EPA has developed a variety of resources to help individuals and communities create and maintain healthy homes.

Learn more about maintaining a healthy home by exploring the links below.