Pollution of Air and Water
Air: Air is a mixture of gases. About 78% of air is composed of nitrogen, 21% is composed of oxygen, and the rest 1% is composed of carbon dioxide, argon, methane, ozone, water vapour, etc.
Air Pollution: When air is contaminated with unwanted substances and becomes harmful to the living and non-living, this is called air pollution.
Air Pollutants: Substances which contaminate air are called air pollutants.
Causes of Air Pollution:
Natural Causes: Smoke and dust from forest fire and volcano
Automobile Exhaust: Petrol and diesel are used as fuel in automobiles. Combustion of these fuels produces many polluting gases; like carbon dioxide, carbon monoxide, sulphur dioxide, nitrogen dioxide, etc. Automobile engines also produce minute particles which remain suspended in air. These particles are called Suspended Particulate Matter (SPM).
Factories: Fossil fuel is also used in factories and hence factories produce pollutants; like carbon dioxide, sulphur dioxide and nitrogen dioxide.
Construction sites and Stone Quarries: Construction sites and stone quarries produce lot of dust particles. Mining activities and power plants also produce dust particles.
Households: Many fuels are used in kitchens, and thus kitchen is a significant source of air pollution.
Ozone Layer: Ozone layer is a protective layer in the atmosphere. It contains a higher amount of ozone than any other layer of the atmosphere. However, compared to other gases; ozone still forms a negligible part of the air in the ozone layer. This layer prevents harmful ultraviolet radiations from the sun from entering our atmosphere. Ultraviolet radiations can cause skin cancer in humans and animals and is also harmful to plants. Any damage to the ozone layer can be highly detrimental to the living beings.
Effects of Air Pollution:
- Carbon dioxide causes global warming because it is a potent greenhouse gas.
- Smog: Smog is a mixture of smoke and fog. Smog reduces visibility and thus can create problems for drivers at highways. Pilots face problems while landing or taking off; due to smog.
- Carbon monoxide is a poisonous gas even at low concentration. It reduces the oxygen carrying capacity of blood, and a person may die on exposure to carbon monoxide.
- Acid Rain: Oxides of sulphur and nitrogen mix with rainwater to create acid rain. Acid rain can be harmful to living beings and also for non-living things. Acid rain corrodes the outer surface of buildings. This has caused the Taj Mahal becoming pale.
- Suspended Particulate Matter in the air can cause respiratory problems; like asthma and other respiratory disease.
- Greenhouse Effect: Greenhouse gases; like carbon dioxide and methane trap solar radiation and thus increase atmospheric temperature. This is called greenhouse effect.
- Global Warming: Overall increase in temperature of the earth is called global warming. Global warming is causing melting of icebergs and glaciers. It is resulting in increased cases of flash floods and a rise in sea level. It is also causing drastic changes in weather patterns.
Addition of unwanted substances in water which makes water harmful to living beings and non-living things is called water pollution.
Water Pollutants: Substances which contaminate water are called water pollutants.
Pollution of Ganges river
The Ganges is an important river for a large section of people of India because millions of people depend on this river for their livelihood. Moreover, Ganges river is considered to be a sacred river by the majority of people in India.
Some of the causes of pollution of this river are as follows:
- Untreated sewage and effluents from cities are discharged into this river.
- The river is used by people for bathing and washing clothes, also for bathing their cattle.
- Cremation of dead bodies on the banks of the Ganges is an age-old practice, and this practice pollutes the river water.
- Rivers are preferred for immersing idols, flower and many other leftovers of rituals and worships.
- Many industrial towns are situated on the banks of this river, e.g. Kanpur.
- The factories release harmful chemicals into this river.
- Rampant use of pesticides and chemical fertilizers pollute river water and groundwater.
Effects of Water Pollution:
Eutrophication: Enrichment of water body with nutrients is called eutrophication. It happens because of the excess amount of chemicals in water. This results in proliferation of algae and other plants in water bodies with stagnant water. Once these plants die, they are consumed by decomposers. The process of decomposition utilizes most of the oxygen from water. This results in the deficiency of oxygen for aquatic animals.
- Contaminated water becomes unfit for consumption by humans and cattle.
- It results in drastic reduction of fish population. Fall in fish population results in loss of livelihood for fishermen.
- Water pollution results in increased cases of water-borne diseases; like cholera, diarrhoea, jaundice, etc.
- Presence of faecal matter results in high concentration of E.coli in water; which causes water-borne diseases.
- Contamination of groundwater results in high levels of toxic materials in fruits, vegetables and grains.
- The pH and temperature of water increase because of untreated effluents from factories. This harms the aquatic plants and animals.
Water which is fit for drinking is called potable water. A quarter of the world’s population does not have access to safe drinking water.
Methods of Water Purification:
- Municipal bodies purify water by various physical and chemical methods before supplying drinking water to households.
- Filtration is a common method of purification of water. Various types of water filter are used in households.
- Boiling is another common method of water purification. It kills the germs in water.
- Chlorination also helps in killing the germs in water. Chlorine tablets are available for free at government hospitals.
How to Prevent Water Pollution:
- Discharge of untreated sewage and effluents in water bodies should be strictly prohibited.
- Every city should have a sewage treatment plant.
- Public awareness about harms of idol immersion should be increased.
- Traditional crematoriums should be replaced with electric crematoriums.
Conservation of Water
- Water is a precious resource, and hence every step should be taken to conserve water.
- We should follow the principles of three Rs, i.e. Reduce, Reuse and Recycle to conserve water.
- We should make changes in our lifestyle to prevent wastage of water.
- Leaking taps should be immediately repaired.
- Using a bucket instead of the shower for a bath helps in saving water.
- Water left after washing clothes and vegetables should be reused for mopping and for washing cars and scooters.
- Sewage water should be purified so that it can be used again.