Question

 

Give a briefly explanation of each of the following five main causes of pollution :

- Exhaust and emissions from vehicles and industries.

-Dumping waste in water bodies.

- Accumulation of non-biodegradable waste (like plastic).

- Excessive use of chemicals (herbicides and pesticides) in agriculture.

- Deforestation and overgrazing.

 

Answer 1

 

• Exhaust and emissions from vehicles and industries.

As a result of the combustion of fuels such as natural gas, gasoline, petrol, biodiesel blends, diesel fuel, fuel oil, or coal, exhaust gas or flue gas are emitted. Motor vehicle emissions are a major ingredient in the creation of smog in some large cities and contribute to air pollution. Mono-nitrogen oxides NO and NO2 (NOx) react with ammonia, moisture, and other compounds to form nitric acid vapor. The largest emissions of NOx came from on road motor vehicles. The second largest contributor being non-road equipment which is mostly gasoline and diesel stations.

• Dumping waste in water bodies

​​Depositing all the waste materials from factories and industries, tankers and ships and sewerage waste materials into the oceans and seas is the process of dumping. Industrial wastes and sewage wastes may contain materials like mercury, cryolite and DDT. Certain industrial wastage also includes radioactive materials of which small amounts tend to have negative effects.

• Accumulation of non-biodegradable waste (like plastic).

Non-biodegradable waste do not decompose. They causes biomagnification by accumulating in the environment. This leads to soil and water pollution. It creates air pollution, if such wastes are burnt.

• Excessive use of chemicals (herbicides and pesticides) in agriculture.

The extensive use of pesticides in agricultural production causes build up of chemical compounds in the soil. This can degrade and damage the community of microorganisms living in the soil. The use of pesticides decreases the general biodiversity in the soil.

• Deforestation and overgrazing

These are inappropriate farming methods that causes soil degradation such as loss of organic matter and nutrient depletion, acidification, salinization, and chemical contamination, as well as deterioration of physical properties, such as water and wind erosion.