Colourless, odourless and non-corrosive air pollutants are

Colourless, odourless and non-corrosive air pollutants are Carbon Monoxide.
Carbon monoxide is a poisonous, flammable gas that is colorless, odorless, tasteless, and slightly less dense than air.
Carbon monoxide is a temporary atmospheric pollutant in some urban areas, chiefly from the exhaust of internal combustion engines but also from incomplete combustion of various other fuels.