Air pollution is the presence of substances in the atmosphere that are harmful to the health of humans and other living beings, or cause damage to the climate or to materials. There are different types of air pollutants, such as gases, particulates (both organic and inorganic), and biological molecules. Air pollution may cause diseases, allergies and even death to humans; it may also cause harm to other living organisms such as animals and food crops, and may damage the natural or built environment. Both human activity and natural processes can generate air pollution.
Pollutants emitted into the atmosphere by human activity include:
- Carbon dioxide (CO2)- is a natural component of the atmosphere, but also because of its role as a greenhouse gas, it has been described as “the leading pollutant.
- Sulfur oxides (SOx)
- Nitrogen oxides (NOx)
- Carbon monoxide (CO)
- Volatile organic compounds (methane or non-methane)
- Particulate matter
- Toxic metals, such as lead and mercury, especially their compounds
- Chlorofluorocarbons (CFCs)
and many others.