class 8 pollution of air and water

Natural Resources: Air and water 💧🌬️
Pollution: Contamination of air and water by toxic substances from human activities 🏭💨
Pollutants: Substances causing pollution (e.g., carbon monoxide, sulphur dioxide) 🚗🏭
Air Pollution: Contamination of air with harmful substances like toxic gases, smoke, and dust 🏭🌫️
Major Air Pollutants: Sulphur dioxide from fossil fuels and automobile exhaust 🚗🔥
Health Effects: Carbon monoxide poisoning, respiratory issues from sulphur and nitrogen oxides 💀🫁
SPM: Suspended particulate matter causing respiratory problems and plant damage 😷🌿
Acid Rain: Formation from fossil fuel burning, damaging monuments, aquatic life, and soil fertility ☔☠️
Greenhouse Effect: Trapping solar radiation with gases like carbon dioxide, causing global warming 🌍🔥
Global Warming Effects: Polar ice melt, agriculture disruption, and climate changes 🌨️🌾
Ozone Layer: Protecting Earth from harmful UV radiation, depletion by chlorofluorocarbons (CFCs) ☀️🌍🛠️
Water Pollution: Contamination of water by sewage, industrial waste, and pesticides 💧🚫
Pollutants: Harmful substances causing foul smell and bad taste 🤢
Causes: Industrial waste, sewage, human activities, oil spills, and agriculture waste 🏭🚽
Health Effects: Cholera, dysentery, gastroenteritis from polluted water 💀🤒
Algal Bloom: Fertilizers causing excessive algae growth 🌱🌊
Eutrophication: Oxygen depletion due to algae growth 💧⚠️
Biological Magnification: Pesticide concentration increase in food chain 🐟🔬
Aquatic Life Impact: Oil slicks suffocate marine life 🐠💔
Prevention: Prohibit activities near water, control waste discharge, enforce pollution rules 🛑🌊
Potable Water: Suitable for drinking, purified by treatment plants 🚰💧
Treatment Process: Sedimentation, loading, filtration, chlorination, storage 🧪🔄
Stored Water: Safe distribution to homes through pipes 🏠🚰

What are the most important natural resources?

Air and Water

Define Pollution??

Contamination of natural resources like air and water by addition of toxic and poisonous substance due to various human activities is called Pollution.

Define Pollutant and give some examples??

Any substance that cause Pollution is called as Pollutant.
Ex: Carbon Monoxide, Oxides of Nitrogen, Oxides of Sulphur, Dust, Smoke, Sewage etc.

When does a substance become pollutant??

A substance become pollutant when its concentration increases beyond the permissible limit in the environment.
Ex: Fertilizers are helpful to increase the crop yield but when added in excess they contaminate the surface water and soil.

Define Air Pollution??

The contamination of air with harmful and unwanted materials like toxic gases, smoke, dust that has harmful effect on both the living and non living organism is called Air Pollution.

Define Air Pollutants??

The harmful and unwanted substances that contaminate the air are called as air pollutants.

Give some Sources of Air Pollutants??

Natural air pollutants are smoke and dust rising from the forest fire, volcanic eruptions
Majority of the air pollutants are added to the environment by human activities like burning of fossil fuel, automobile exhaust and industrial emission.

List the two major air pollutants and its sources??

Sulphur dioxide- burning of fossil fuels, automobile exhaust, petroleum product refineries volcanic eruptions.

How air pollution causes health issues??

Carbon Monoxide

It is a very poisonous gas
It is colourless and odourless
When carbon monoxide is inhaled it combines with haemoglobin of the blood and forms carboxy haemoglobin
This prevents carrying of oxygen by the blood to the various parts of the organs
It results in unconsciousness and even death.
Oxides of sulphur causes respiratory problems and damage lungs.
Oxides of nitrogen causes long congestion
Fumes from chemical industries result in irritation in eyes, throat, nose etc.
Particles of the lead oxide from automobile exhaust causes a mental disorder and brain damage
Particles of the dust can cause a bronchitis.

What is SPM? What are its effect on humans??

SPM means Suspended Particulate Matter
Ex: for SPM are Unburnt carbon particles from automobile exhaust, fine particles of lime, cement.
It causes irritation in nose throat respiratory tract. It damages lungs.
SPM can block the stomata of the plant and inhibits photosynthesis.

Define Acid Rain??

Due to burning of fossil fuel such as Coal, Petrol, Diesel it produces Carbon dioxide, Carbon monoxide, Oxides of Sulphur, Nitrogen and unburned hydrocarbons.
Oxides of carbon monoxide, Sulphur and Nitrogen reacts with water vapour than the atmosphere and result in the formation of Carbonic acid, Sulphuric acid, Nitric acid.

What are the damaging effects of acid rain??

It promotes corrosion of the metallic objects like bridges and gates.
It destroys the monuments and buildings.
It can damage the aquatic plants and animals.
It leads to loss of soil fertility.

Define Green house effect ??

The phenomenon were the earth’s atmosphere traps the solar radiation because of presence of gases like carbon dioxide oxides, water vapour, methane, CFC’s

( Chloroflurocarbons) is called Green house effect.

What are the causes when there is No green house gases??

If there is no green house gases, the earth surface will be too cold and life cannot exist. The increase in green house gases it can lead to increase in the average temperature of 🌎 Earth .

What are the adverse effects of Global Warming ??

Polar caps melt and increase in the sea level.
It causes low lying areas near coast to be submerged.
It greatly affects the agriculture and the production of the food.
Climate and rainfall pattern changes.

Define Ozone Layer??

Ozone gas forms the layer in the Stratosphere of the atmosphere.
It prevents harmful UV radiation coming from the Sun to enter the earth.

What are the causes of ozone layer depletion??

Chlorofluorocarbons are used in refrigerator AC, aerosol spray, when released in the air it damages the ozone layer of the atmosphere.

What are the harmful effects of ozone layer depletion??

Harmful UV radiation causes various diseases such as cataract, skin cancer, damage of eyesight etc.
It causes change in the gene structure through mutations.
Harmful UV damages the early development and stages of the fish, crab and other animals.

Ozone hole

There is a massive hole in the ozone layer due to the increase release of carbon dioxide.
It is above the Antarctica.
Ozone hole is expanding now exposing harmful UV radiation of the sun to the South America.

List the methods to prevent and control air pollution ??

Use modern automobile engine that leads to complete combustion of the fuel reducing the release of carbon monoxide and smoke.
Use environmentally clean fuel. CNG – Compressed Natural Gas. It produces less pollutants.
Use lead free petroleum automobiles.
Regularly check the vehicles for pollution.
Grow more trees and plants to reduce greenhouse effect.
Use recycled paper to save trees
Replace wood, cool and kerosene with LPG.
Use hydroelectricity solar energy and wind energy
Encourage the use of public transport.
Organise awareness in localities to reduce noise pollution.

Water Pollution

Define Water Pollution??

Contamination of the water with unwanted and harmful substances such as domestic sewage, toxic industrial waste, pesticides fertilizers, that cause harmful effects on both the living and nonliving object is called Water Pollution

What are Water Pollutants??

The harmful and unwanted substances that contaminate water are called water pollutants.
These pollutants in water result in fowl smell and bad taste.

What are the various causes of Water Pollution??

Industrial waste

Industry such as Paper, Textile, Leather, Paint produce harmful waste such as Lead, Mercury, Arsenic, etc.
They discharge these chemicals containing water directly into the nearby water bodies.
This result in water pollution.

Domestic waste

Liquid waste from kitchen, toilet are it is discharged directly from sewage system into the nearby water bodies resulting in Pollution.

Human activities

Bathing of animals, humans in water bodies such as Pond, Lake, River result in Water pollution.

Oil spills

Oil spills from huge tankers result in major cause of Water pollution in seas and ocean that affect the marine plants and animals.

Agriculture Waste

Large quantities of Pesticides and Fertilizers usage result in underground Water Pollution.

How Water Pollution affects the human health??

Polluted water causes diseases such as Cholera, Dysentery, Typhoid, Gastroenteritis, Jaundice, Diarrhoea in humans.

Define Algal Bloom??

When large amount of fertilizers are flowed into water bodies it causes increased growth of algae and other weeds. This is called Algal Bloom.

Define Eutrophication??

Due to increase availability of nutrition its stimulates the growth of algae and other weeds that result in depletion of dissolved oxygen called Eutrophication.

Define Biological Magnification??

The increase in concentration of harmful chemical substances like Pesticides in the body of living organism at each trophic level of food chain is called Biological Magnification.

Ex: DDT

DDT in water – 0.000003 ppm
Zooplankton – 0.04ppm
Small fish – O.5 ppm
Large fish – 2 ppm
Fish eating bird – 25ppm

How Water Pollution in seas and oceans affect the aquatic life??

Accidental leakage of crude oil from large oil tankers pollutes the sea and ocean water.
Since oil is lighter than water it form certain film on the surface of the water called as oil slick.
Oil slick does not allow light and air to penetrate easily in water.
This will kill thousands of marine plants and animals.
Cleaning of oils slick with detergent can also damage the Marine habitat.

List few methods to prevent Water Pollution??

Washing clothes, Cleaning utensils, taking bath near the water bodies should be prohibited.
Do not use excessive fertilizer and pesticides.
Domestic sewage and industrial sewage should be treated in sewage plant before it discharging them into the water bodies.
Pollution control rules by the government should be followed very strictly.
Dead bodies should be properly buried or cremated it should not be disposed in water bodies.
Educate the public about the harmful effects of Water Pollution.

Define Potable Water??

Water that is suitable for drinking is called Potable Water.

What is Water Treatment plant??

Before the water reaches our home it is cleaned to remove the impurities and microorganisms. It is done by Water Treatment Plant.

What are the various tanks involved in Water Treatment Plant??

Sedimentation tank
Loading tank
Filtration tank
Chlorination tank
Storage tank

What is done in Sedimentation Tank??

Water from the rivers or lakes is first pumped into the Sedimentation Tank.
Water is allowed to stand for a day.
Large insoluble impurities settle down at the bottom of the tank.
Light insoluble impurities remains suspended in water.

What is loading??

Water from the sedimentation tank are passed into the loading tank.
Suspended impurities are made to settle down faster by the addition of Alum. This process is called loading.

What happens in filtration tank??