Air pollution happens when gases, dust particles, fumes or smoke are introduced into the atmosphere in such a way that makes them harmful to humans, animals or plants.
Examples of pollutants include nitrogen oxides, carbon monoxides, hydrocarbons, sulphur oxides (usually from factories), sand or dust particles, and organic compounds that can evaporate and enter the atmosphere.
Different types of pollutant
Carbon monoxide (CO)
- Comes from fuel combustion from vehicles and engines.
- Reduces the amount of oxygen reaching the body’s organs and tissues; aggravates heart disease, resulting in chest pain and other symptoms.
Ground-level ozone (O3)
- Secondary pollutant formed by the chemical reaction of volatile organic compounds and nitrogen oxides in the presence of sunlight.
- Decreases lung function and causes respiratory symptoms, such as coughing and shortness of breath, and also makes asthma and other lung diseases worse.
- Comes from metal industries, combustion of leaded fuel in piston engine aircraft, waste incinerators, and battery manufacturing.
- Damages the developing nervous system, resulting in IQ loss and impacts on learning, memory, and behaviour in children; cardiovascular and renal effects in adults.
Nitrogen dioxide (NO2)
- Comes from fuel combustion (electric utilities, big industrial boilers, vehicles including buses) and wood burning.
- Worsens lung diseases leading to respiratory symptoms, increased susceptibility to respiratory infection.
Particulate Matter (PM)
- This is formed through chemical reactions, fuel combustion (eg, burning coal, wood, diesel), industrial processes, farming, and unpaved roads or during road constructions.
- Short-term exposures can worsen heart or lung diseases and cause respiratory problems. Long-term exposures can cause heart or lung disease and premature deaths.
Sulphur dioxide (SO2)
- SO2 comes from fuel combustion, electric utilities and industrial processes.
- Aggravates asthma and makes breathing difficult. It also contributes to particle formation with associated health effects.