Human activities that lead to air pollution are

•Use of automobiles as they use fuels like petrol which release toxic compounds when burned in the engine of the vehicle thus making the air polluted.

•Burning of fossil fuels like coal release carbon in the atmosphere which causes smog.

•Use of Chloroflourocarbons in refrigerators and air conditioners releases chlorine atoms in the atmosphere which deplete the ozone layer.

•Industries release a lot of harmful gases like sulphur dioxide, oxides of nitrogen, heavy metals which pollute the atmosphere.