pollution of air and water notes
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Air Pollution
Contamination of air by unwanted substances which have a harmful effect on both the living and the non-living is referred to as air pollution. A thick fog-like layer in the atmosphere especially during winters is smog which is made up of smoke and fog. Smoke contains oxides of nitrogen which combine with other air pollutants and fog to form smog. The smog causes breathing difficulties such as asthma, cough and wheezing in the children.
Air Pollutants
The substances which contaminate air are called air pollutants. Sometimes, such substances may come from natural sources like smoke and dust arising from forest fires or volcanic eruptions or by certain human activities.
This Acid rain corrodes the marble of the monument through a phenomenon called the “Marble cancer”. Suspended particulate matter such as the soot particles emitted by oil refineries and other factories have contributed towards the yellowing of the marble of Taj Mahal.
Green House Effect
The trapping of radiations by the earth’s atmosphere is similar to how the greenhouse traps heat to keep the plants inside the greenhouse warm. That is why it is also called the greenhouse effect. Without this process, life is not possible on the earth. But the excess of this phenomenon threatens and endangers life on Earth.
Greenhouse Gases
Gases like CO2, methane, nitrous oxide and water vapours also contribute to the greenhouse effect hence they are called greenhouse gases
Global Warming
The gradual increase in the average temperature of the Earth’s atmosphere is called global warming. Global warming can cause sea levels to rise and affect rainfall patterns, agriculture, forests, plants and animals.
Deforestation leads to an increase in the amount of CO2 by reducing the number of trees which consume CO2. Human activities contribute to the accumulation of CO2 in the atmosphere adding to the greenhouse effect and thus eventually Global Warming.
What can be done to reduce air pollution?
A decision was taken by the government to switch to fuels like CNG unleaded petrol in vehicles which have resulted in cleaner air for the country.
“Say no to crackers” campaign was organized by children from many schools and it made a big difference to the air pollution levels around Diwali.
Switching over to alternative fuels like solar energy, hydropower and wind energy instead of fossil fuels for our energy requirements could help a lot.
Small contributions on our part like Aforestation can help a lot. Van Mahotsav are organized every year in July when lots of trees are planted. So we can help plant trees and nurture the ones already present in the neighbourhood.
Water Pollution
Water is another one of the most important elements which is required for sustenance of life on Earth. But clean water is what gives us life whereas contaminated water can give us diseases.
Potable Water
The water suitable for drinking is called potable water.
Water Pollution
The contamination of water by unwanted and harmful substances is called Water pollution.
Water Pollutants
The substances that pollute water like sewage, toxic chemicals, silt, etc. are called water pollutants.
Causes of Water Pollution
Many industries like oil refineries, paper factories, textile and sugar mills and chemical factories discharge harmful chemicals into rivers and streams, causing the pollution of water. This is called chemical contamination of water. The chemicals released into the water include arsenic, lead and fluorides which lead to toxicity in plants and animals. There are regulations to prevent this and industries are supposed to treat the waste produced before discharging it into water but the rules are not followed very often. The soil is also affected by the impure water causing changes in acidity, growth of worms, etc in the soil.
All the chemicals in weedicides and pesticides dissolve in water and are washed into water bodies from the fields and even seep into the ground and pollute groundwater. These chemicals in the water bodies act as nutrients for algae to flourish which serve as nutrients for algae to flourish. A lot of oxygen is used up by these unwanted processes which results in a decrease in the oxygen level and can kill aquatic organisms.
Untreated sewage with food wastes, detergents, micro-organisms etc. when thrown directly into the water bodies also causes water pollution. Water contaminated with sewage may contain bacteria, viruses, fungi and parasites which can cause diseases like cholera, typhoid and jaundice.
Hot water can also become a pollutant
How to Make Water Safe
Filtering- A popular household filter is a candle type filter.
Boiling- Many households use boiling for obtaining safe drinking water. Boiling kills the germs present in the water and makes it safe for drinking.
Chlorination– It is a commonly used chemical method for purifying water done by adding chlorine tablets or bleaching powder to the water. But more chlorine tablets than specified should not be used because they are harmful.