We can categorize the causes of air pollution into two major categories:
- Natural Causes
- Anthropogenic Causes (by Human)
Both these causes contribute to introducing particulates and gases into the atmosphere.
Air pollution is the mixing of unwanted and harmful substances such as chemicals, dust, gases, and suspended particles in our atmosphere. It can be of two types: Indoor and Outdoor pollution.
Air pollution is a severe threat to the health of living beings and ecosystems. According to WHO, it was the cause of death of approximately 7 million people worldwide in 2014.
To learn more, visit the comprehensive guide on air pollution.
Anthropogenic Cause of Air Pollution
Several human activities have been consistently polluting the air we breathe. This is categorized under anthropogenic causes of air pollution.
These activities include:
1. Discharges from manufacturing industries and factories
The emissions from manufacturing industries are one of the major causes of air pollution. Harmful particulate matter and gases enter the atmosphere from this source.
Major pollutants such as oxides of nitrogen and sulfur, carbon monoxide/carbon dioxide, and other chemical wastes are deteriorating the quality of the air everywhere.
2. Exhaust from vehicles
Pollution from automobiles is clearly visible in every city in the world. Vehicles run on fossil fuels such as petroleum and gasoline that emit soot and harmful gases like CO and NOx.
These gases are among the major air pollutants in the environment.
3. Burning of fossil fuels in power plants
Power plants burn a massive amount of fossil fuels such as gas and coal to produce electricity. This results in the mass production of sulfur dioxide, carbon dioxide, and nitrogen dioxide among others.
4. Mining activities
Mining involves different operations such as drilling, extracting, blasting, and transportation. Air pollution from mining is caused by gases such as methane, carbon monoxide, sulfur dioxide, etc.
Dust and particulate matter during the different stages of mining (blasting, drilling, and extracting) are some of the other pollutants affecting the atmosphere.
The increased use of fertilizers and pesticides releases unwanted chemicals into the atmosphere.
Also, ammonia-based fertilizers used in agriculture are some of the harmful air pollutants.
6. Causes of Indoor Air Pollution
Apart from those mentioned above, chemicals used in cleaning houses, paints (contains lead), and suspended particulate matter are the major cause of indoor air pollution.
Natural Causes of Air Pollution
Most of the air pollution is caused because of the ignorance and negligence of humans, but it is also true that sometimes the air can be polluted by natural causes.
The natural factors causing air pollution are:
1. Forest Fires
Forest fires produce giant masses of smoke, which tend to drift over nearby villages and cities.
2. Volcanic eruptions
Occasional eruptions of volcanoes can eject huge amounts of volcanic ash and lava onto the earth’s surface. This introduces dust and smoke into the atmosphere, thereby polluting the air.
3. Radioactivity released from the decay of rocks
Over time decay of rocks releases gas such as radon which has adverse effects on human health. This can be one of the major natural causes of air pollution.
4. Wind Erosion
Wind erosion tends to mix the dust particles from the soil into the atmosphere, thus causing air pollution naturally.
Major Pollutants That Cause Air Pollution
Pollutants are substances that affect the air adversely. Below mentioned are the major pollutants causing air pollution:
1. Ozone: Harmful ozone is found in the lower part of our atmosphere or near the earth’s surface. It can cause respiratory ailments such as asthma. Whereas the ozone layer at 6-30 miles above the surface protects us from ultraviolet rays.
2. Sulfur dioxide: One of the main elements that cause acid rain. The burning of fossil fuels is one of the major sources of sulfur dioxide.
3. Nitrogen oxides: It is a component of ozone and also forms acid rain.
4. Carbon monoxide: Automobiles and poorly maintained heaters are the major sources that emit carbon monoxide.
5. Particulate Matter: They are coarse or fine particles that may enter our lungs and cause problems in respiration.
6. Volatile Organic Compounds: They are of two types: methane and non-methane volatile compounds. Methane contributes to global warming, and other compounds help form the ozone.