Declare your home a smoke-free zone. Secondhand smoke can cause serious health problems, especially for children. Ask smokers to take it outside.
Good ventilation reduces indoor air pollution.
Leave doors between rooms open most of the time for better air circulation. Open windows when possible to allow for a good supply of outdoor air. Install exhaust fans in bathrooms to remove moisture and chemicals from the house. Clean both regularly so they don't become a source of pollutants themselves. Fix all leaks and drips in the home, as standing water and high humidity encourages the growth of mold and other biological pollutants.