Breakdown of Air Pollutants and Their Sources
Particulate Matter (PM):
Fine particles that are measured as micrometres (m) in diameter. Transportation emissions, combustion and industrial processes, are the sources of PM.

Ground level ozone(O3):
Formed when nitrogen oxide and volatile organics compounds react with each other under the presence of sunlight.
Nitrogen oxides (NOx):
Contain nitrogen compounds, including nitric oxide (NO) and nitrogen dioxide (NO2), which are released during combustion within car engines and thermal power plants.
Heavy metals:
Are released as a result of burning metals in power plants and industrial processes such as waste combustion and coal purification.
Volatile organic compounds(VOCs ):
Compounds that are released from solvents, paints and glazes and are emitted into the atmosphere via car exhaust fumes and gas station activities, certain industrial processes, and agricultural activities.
A widely used industrial solvent that is released from various sources in industrial activities, from vehicle exhausts, gas stations, wood smoke and many other sources, including cigarettes.

Ammonia (NH3):
Released from animal waste and fertilizers.
Carbon monoxide (CO):
Carbon monoxide is an odorless and colorless gas.
Sulphur dioxide (SO2):
Emitted during the burning of fossil fuels.