Indoor pollution majorly refers to air & noise pollution. Following are the main causes of indoor pollution.

1. Pollutants are also found indoors from infiltration of polluted outside air and from various chemicals used or produced inside buildings. Both indoor and outdoor air pollution are equally harmful.
2. Indoor air pollution occurs due to the use of fuel wood, waste material, coal, etc. in ‘chulas’. Indoor smoke arising from ‘Chulas’ is a major issue in rural India. Thousands of women and children die yearly due to it.
3. ‘Second hand smoke’ i.e. tobacco smoke affecting other people apart from active smoker is also a major indoor pollutant.
4. Molds & other biological particulate substances like plant pollen & animal dander.
5. Volatile Organic Compounds (VOCs) arising from paints, lacquers, thinners, pesticides, whiteners, glues etc. are found in much higher concentration indoors than outdoors.
6. Loudly played radio or music systems, and other electronic gadgets can contribute to indoor noise pollution.