1952 was bad year for London when week-long intense fog and smoke resulted in death of over 4,000 people and around 100,000 became ill due to respiratory tract infections.
Air is among one of the essential elements which make life possible on the earth. So it is important to protect the air from the pollution. Air pollution is the accumulation of substances in the atmosphere which endanger the humans, animals, plants and other life forms.
The main source of air pollution are heat and power generation, industrial processes, burning of solid wastes and transportation. The major pollutants are carbon monoxide, hydrocarbons and oxides of sulfur and nitrogen.
Air pollution is classified into two types:
Primary Air Pollutants:
These are the pollutants which are directly emitted from the source of generation. These include CO, SO2, NO2, HC, HF, NH3 and H2S.
Secondary Air Pollutants:
These are produced in the atmosphere by the reaction of primary pollutants with one another or with other chemicals in the air. Examples of secondary pollutants are SO3, HNO3, PAN and Aldehydes.
Smog is a type of air pollution which is produced by emission from internal combustion engine and industrial fumes which when react with sunlight in atmosphere form secondary pollutants. These secondary pollutants then combine with primary sources of emission and produce photochemical smog. This type of smog happens in places which are hot, dry and sunny as well as heavy street traffic. Smog is produced by large amount of burning of coal in an area.
There are some pollutants which are very toxic to health as well as to the environment. These include Asbestos, Mercury, Radon, Arsenic, Benzene and Beryllium. EPA has identified 188 compounds as “Hazardous Air Pollutants”. These include extremely toxic substances like Carcinogens and Mutagens. North Carolina has also identified 105 “Toxic Air Pollutants” with acceptable ambient levels.
There are some pollutants which are considered Global Air Pollutants because of their global impact and distribution. These are Chlorofluorocarbons that are responsible of breakdown of Ozone layer and Carbon dioxide which is related to greenhouse effect.
Thank you for reading! Stay Safe!👋😌