Humans are today exposed to air pollution of all kinds, and affected by the harmful effects of the pollutants in the air they breathe. There are many causes of air pollution. One of the causes is vehicular traffic. Smoke generated by factories is also let out into the air. The burning of fossil fuels like coal also leads to harmful smoke.

The high levels of air pollution cause respiratory and cardiac problems, and affect other parts of the human body. It also causes other diseases like cancer. Millions of people around the world die each year due to air pollution.