Air pollutants are substances present in the air that can harm human health, wildlife, and the environment. They come from various sources including:
1. Industrial chimneys: Industries such as power plants, manufacturing facilities, and refineries release pollutants like sulfur dioxide, nitrogen oxides, and particulate matter into the air through their chimneys.
2. Vehicle exhausts: Cars, trucks, buses, and other vehicles emit pollutants like carbon monoxide, nitrogen oxides, and particulate matter into the air.
3. Burning fossil fuels: The burning of fossil fuels such as coal, oil, and natural gas releases pollutants like sulfur dioxide, nitrogen oxides, and carbon monoxide into the air.
4. Sewage: Waste from sewage treatment plants and septic systems can emit pollutants like methane and nitrogen into the air.
5. Smoke: Open burning of waste, forest fires, and other sources of smoke can emit pollutants like particulate matter and carbon monoxide into the air.
It's important to note that not all sources of air pollutants are man-made. Natural sources such as volcanic eruptions, dust storms, and wildfires also contribute to air pollution.