Air quality

Indoors

Asbestos
Biological pollutants
Carbon monoxide (CO)
Formaldehyde
Lead (Pb)
Mercury (Hg)
Nitrogen dioxide (NO2)
Noise (indoor)
Pesticides
Radon (Rn)
Secondhand tobacco smoke
Volatile organic compounds (VOCs)

Potential sources of indoor air pollution

Indoor air levels of many pollutants may be 2-5 times, and occasionally, more than 100 times higher than outdoor levels. Indoor air pollutants are of particular concern because most people spend as much as 90% of their time indoors.

Common sources can include burning kerosene, wood or oil, smoking tobacco products, releases from household cleaners, pesticides, building materials, and radon.