Causes of Air Pollution
There are various factors causing air pollution; natural and anthropogenic, which contribute to the introduction of particulates and gases into the atmosphere.
Air pollution is the mixing of unwanted and harmful substances such as chemicals, dust, auto emissions, suspended particles, gases among others in our atmosphere. It can be of two types; indoor and outdoor air pollution. It is a serious threat to the health of living beings and the different ecosystems found in our environment. According to WHO, it was the cause of death of approximately 7 million people around the world in 2014.
Needless to say, there are several human activities which have been consistently polluting the air we breathe. 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 and 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 of the world. Vehicles run on fossil fuels such as petroleum and gasoline that emit soot and harmful gases such as CO and NOx which 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 and as a result results in the mass production of pollutants such as sulfur dioxide, carbon dioxide and nitrogen oxide among others.
4. Mining activities
Mining involves different operations such as drilling, extracting, blasting and transportation. Air pollution from mining is caused because of release of gases such as methane, carbon monoxide, sulfur dioxide etc. and other dust and particulate matter during various stages of mining.
Ammonia based fertilizers, which is abundantly released during agriculture, is one of the harmful air pollutants. Also the increased practice of using fertilizers and pesticides by farmers also releases other unwanted chemicals in the atmosphere.
6. Indoor pollution
Substances causing indoor pollution are chemicals used in cleaning, paints containing lead and suspended particulate matter.
Major Pollutants That Cause Air Pollution
Pollutants are the substances that affect the air adversely. Below mentioned are the major pollutants in found in polluted air.
- Ozone: Harmful ozone is found in the lower part of our atmosphere or near the earth surface. It can cause respiratory ailments such as asthma. Whereas, the layer of ozone at 6-30 miles above the surface protects us from ultraviolet rays.
- Sulfur dioxide: It is produced when fossil fuels are burned. It is one of the main elements that cause acid rain.
- Nitrogen oxides: Nitrogen dioxide is a component of ozone and also forms acid rain.
- Carbon monoxide: It is majorly emitted by automobiles and indoors it is emitted by poorly maintained heaters.
- Particulate matter: They are coarse or fine particles which may enter our lungs and cause problems in respiration.
- Volatile organic compounds: They are of two types; methane and non-methane volatile compounds. Methane contributes to global warming and other compounds help in the formation of ozone.
Natural Causes of Air Pollution
Most of the pollution of the air is caused because of the ignorance and negligence of humans but it is also true that some time the air can be polluted by natural causes.
The natural factors causing air pollution are:
- Forest fires
- Wind erosion
- Radioactivity released from decay of rocks
- Volcanic eruptions.
Forest fires produce giant masses of smoke which tend to drift over nearby villages and cities.
Occasional eruptions of volcanoes can eject huge amount of volcanic ash and lava onto the earth surface which introduces dust and smoke into the atmosphere thereby polluting the air.
Natural air pollution can also be caused when rocks decay over time and release gas such as radon which has adverse effects on our health.