Air pollution happens once harmful or excessive quantities of gear together with gases, particulates, and biological molecules ar introduced into Earth's atmosphere. it's going to cause diseases, allergies and even death to humans; it's going to conjointly cause damage to different living organisms like animals and food crops, and should injury the natural or engineered surroundings. each human action and natural processes will generate pollution.

Indoor pollution and poor urban air quality ar listed as 2 of the world's worst unhealthful pollution issues within the 2008 metalworker Institute World's Worst contaminated Places report.[1] consistent with the 2014 World Health Organization report, pollution in 2012 caused the deaths of around seven million folks worldwide,[2] associate estimate roughly echoed by one from the International Energy Agency