Human activity is responsible for most of the world’s air pollution, both indoors and outdoors. Everything from smoking cigarettes to burning fossil fuels tarnishes the air you breathe and causes health problems as minor as a headache to as harmful as respiratory, lung and heart disease.
TL;DR (Too Long; Didn't Read)
The burning of fossil fuels such as coal, gasoline and kerosine produces most of the world's air pollution.
Types of Pollutants
Man is at least partially at fault for most of the world’s major air pollutants. Carbon dioxide is one of the most highly prevalent, comes from the combustion or burning of fossil fuels and other organic materials. Nitrogen oxide and dioxide, while both natural components of the Earth's atmosphere, occur in greater amounts due to human actions and are the cause of smog and acid rain.
Pollutants also include chlorofluorocarbons (CFCs), were widely used as refrigerants and aerosol propellants. These chemicals damage the ozone layer, which is why the Environmental Protection Agency banned them in 1978.
Particulates, microscopic particles of soot, pose yet another common hazard. Smoke from burning coal and diesel fuel has been one major source of particulate emissions. In addition to being harmful to breathe, particulates form a dark film on buildings and other structures.
Causes of Air Pollutants
The burning of fossil fuels such as coal and gasoline is the single largest source of air pollutants. Fossil fuels continue to be in wide use for heating, to operate transportation vehicles, in generating electricity, and in manufacturing and other industrial processes. Burning these fuels causes smog, acid rain and greenhouse gas emissions.
Burning fuels also increases some heavy metal contaminants and the amount of soot in the air. Power plants and factories emit much of the sulfuric air pollutants. In all, industrialized nations – particularly the United States and the Soviet Union – are responsible for most of the world’s air pollutants.
Smog is one of the most dangerous air pollutants to humans and other biological organisms. It is made when coal and oil containing minor amounts of sulfur are burned. The oxides of these sulfur particles form sulfuric acid, which is toxic to life and damaging to many inorganic materials. Air pollution can damage human life, especially in major cities where there is a conglomerate of industries and fumes from vehicles.
Pollution harms the living environment. Sulfur dioxide, nitrogen oxides and peroxyacl nitrates enter leaf pores and damage plants that way. Pollutants also break away the waxy coating of leaves that prevent excessive water loss, causing further damage to crops and trees that are important to the surrounding environment.
Deadly Pollution Incidents
When man-made pollution aggregates over a city with a large population, dangerous situations can develop quickly. Two historical incidents of major pollution-related deaths and illnesses show how badly pollution can affect humans over a short period.
The first occurred in Donore, Pennsylvania, in 1948. Over several days, a high-pressure weather system trapped a large mass of stagnant air over the city, leading to dangerous levels of smog. The smoke from steel production had nowhere to go and accumulated in the air, causing 20 deaths and 6,000 cases of illness. In London, in 1952, a similar situation caused between 3,500 and 4,000 deaths in five days. While air pollution illnesses and deaths usually don’t occur over such short periods of time, these are examples of worst-case scenarios with the possibility of occurring again if air pollution isn’t mitigated.