What is indoor air pollution

The indoor environment is the internal environment of the house and the case where the concentration of air pollutants such as nitrogen dioxide is higher in the room than the outside air is called indoor air pollution. Factors of air pollution include fungi, mites, formaldehyde, and volatile organic compounds.
(1) formaldehyde ... wallpaper, particleboard, medium quality fiberboard, plywood, flooring, furniture, textile products
(2) toluene ... paint
(3) Xylene ... paint
(4) Wood preservatives
(5) Plasticizer ... curtain, wax
(6) termite control agent