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The impact of pollution on health may be primary or secondary. The primary impact occurs immediately but the secondary impact is delayed and may persist in future.

1. When contaminated water is supplied to the residents of a locality, it may spread water-borne diseases like diarrhoea, hepatitis etc.

2. Release of smoke as vehicular exhaust pollutes the air. When this air is inhaled by the humans it causes asthma and bronchitis.

3. Large amount of soluble nitrates are released and dissolve in the water. It may contaminate the groundwater including wells of the area. Heavy intake of nitrates by humans may cause serious health hazards.

4. People who work in the deep coal mines, inhale the fine coal dust. It leads to a disease called black lungs. Many gases are also released in the process of mining like methane and carbon monoxide.

Because of greenhouse effect, there is increase in the global temperature. The heat on the earth remains trapped due to envelope of greenhouse gases. The percentage of carbon dioxide and methane is constantly increasing and hence there is increase in the temperature too. Thus the greenhouse effect is directly related to the global warming.

Effects of this relation between greenhouse effect and global warming are as follows:

1. The polar ice caps and the glaciers at both the poles are melting due to increased temperature. 

2. The oceans’ water is rising due to this melted ice. The sea level rise is causing coastal land submergence. The islands at various regions are threatened of drowning. 

3. Many species of living organisms are already extinct due to global warming. The rest are also threatened. 

4. Wild animals are showing weird migrations. Polar bear is endangered. 

5. The increased temperature of the oceanic water is causing many changes in the tides and currents. This results into increased occurrence of cyclones, hurricanes and cloud bursting. The natural disasters are rising in last decade. 

6. The agricultural production is decreasing. The regions with less rainfall are facing draughts.

1. The ozone layer is present at the top of the stratosphere. The stratosphere is the second layer of the atmosphere which is present 48 km above the earth’s surface. 

2. Ozone layer is protective layer for living organisms of the earth, as it absorbs harmful UV rays from the sun. When this layer is reduced or destroyed, it is called ozone layer depletion.

3. Causes of the ozone layer depletion:

1. The main cause of ozone depletion are CFC molecules. 

2. Chlorine atoms are present in chlorofluorocarbons (CFC) molecules. They react with ozone and deplete it.

3. CFCs are used as coolants in refrigerators, freezers and air conditioners manufactured before 1995. 

4. CFCs are also present in industrial solvents, dry cleaning agents and hospital sterilants (sterilizers), aerosols and foam. All the above materials release a lot of CFCs into the atmosphere. 

5. CFC molecules are broken down by ultraviolet radiations which result in release of chlorine and fluorine, which further reduce the ozone layer.

Carbon dioxide gas is released into the atmosphere in a large quantity. Excessive release of carbon dioxide leads to green house effect that increases the average temperature of earth. It is also referred to as the global warming. Amount of carbon-dioxide has increased by 28% in the last one hundred years which is attributed to burning of fossil fuels like coal, gas and oil.

1. When the ozone layer is depleted, the ultraviolet radiations of the sun can reach the earth’s surface in greater proportion. 

2. This results in damage to animal and plant life on the earth. 

3. Ultraviolet rays cause skin cancer and cataract in human beings. 

4. The ozone hole is seen in the stratosphere above Antarctica.

When we breathe air containing carbon monoxide, it is absorbed through the bloodstream where it displaces oxygen and bonds with the haemoglobin in your blood. Carbon monoxide as a greater affinity to haemoglobin than oxygen; CO bonds to haemoglobin about 250 times better than oxygen. Without oxygen, vital organs, your heart and brain becomes deprived and will begin to deteriorate. To compensate, your heart rate increases, breathing may become difficult and in the most serious circumstances cardiac trauma, brain damage, coma and even death will result.

Preventing pollution offers important benefits, as pollution created never avoids the need for expensive investments in waste management and cleanup. By anticipating the future, pollution prevention reduces both financial costs (waste management and cleanup) and real environmental costs (health problems and environmental damage): As a result, pollution; prevention holds the exciting potential of protecting the environment and strengthening economic growth through more efficient production and natural resource use.

Air pollution due to traffic

A symbiotic bacteria is Rhizobium.

Chlorofluorocarbons (CFCs) are nontoxic, nonflammable chemicals containing atoms of carbon, chlorine, and fluorine. They are used in the manufacture of aerosol sprays, blowing agents for foams and packing materials, as solvents, and as refrigerants. CFC = s react with sunlight in the earth’s stratosphere to break down the protective ozone layer, a layer of gas that shields the earth’s surface from damaging UV-B rays.

The upper part of stratosphere contains large amount of Ozone gas. The ozone gas blocks the harmful ultraviolet rays reaching earth. It has been proved that chlorofluorocarbons or CFC are released from the refrigeration system, air conditioning systems, spray cans etc. These CFC’s are light and are able to reach at height of stratosphere. Here they react with the ozone gas. In this process the chlorine gas is released which reacts with the ozone gas. It breaks apart the ozone molecules thus reducing them in the stratosphere. As a result, the ultraviolet radiation is able to reach the surface of earth. These rays can cause skin cancer, cataract and affect the immune system of the body.

The CFCs cause damage to the ozone layer which protects us from the harmful effects of ultraviolet rays present in sunlight. Hence, its use is banned in some countries.

Ozone is a gas that is made up of three oxygen atoms (O₃). Ozone is classified as either stratospheric (good ozone) or ground level (bad ozone).

A free living bacteria Azotobacter helps in nitrogen fixation.

The chemical element Mercury caused the minamata disease in Japan.

Effects of global warming are :

1. As the increase in temperature will be uniform all over the surface of the world. There will be serious climatic changes. This will bring various changes in wind and rain pattern.

2. Higher temperature will cause rise in transpiration. This in turn, will affect the groundwater table.

3. As the climatic belts shift from equator towards pole, the vegetation would also shift away from the equator.

4. Insects and pests will increase in the warmer climatic conditions. Thus, pathogenic diseases will multiply.

Ozone depletion and global warming are separate problems, though some agents contribute to both. Chlorofluorocarbons (CFCs) are the principal cause of ozone depletion, but they also happen to be potent heat-trapping gases. Still, CFCs are responsible for less than 10 per cent of total atmospheric warming, far less than the 63 per cent contribution of carbon dioxide. Thus, attention paid to CFCs has been on their ozone depletion role. This will change as CFCs are phased out and replaced by hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs such as R-134a). These chemicals have little or no effect on the ozone layer but are strong heat-trapping gases. As their concentration in the atmosphere is already rising, the likely net effect in the future is that reductions in the CFC-related contribution to global warming will be offset by the presence of HCFCs and HFCs.

Soil acts as a storage reservoir for water and other plant nutrients.

Stratospheric ozone or good ozone is a layer surrounding the earth’s atmosp here. It protects all life on earth from the damaging effects of the sun’s rays. Ground level ozone is formed by a photochemical reaction between atmospheric oxygen (O₂) and smog forming chemicals at the earth’s surface, it is odourless and colourless, but can have profound effects on the human respiratory system.

Acid Deposition: Commonly called acid rain—is caused by emissions of sulphur dioxide and nitrogen oxides. Although natural sources of sulphur oxides and nitrogen oxides do exist, more than 90% of the sulphur and 95% of the nitrogen emissions occurring in eastern North America are of human origin. These primary air pollutants arise from the use of coal in the production of electricity, from base-metal smelting, and from fuel combustion in vehicles. Once released into the atmosphere, they can be converted chemically into such secondary pollutants as nitric acid and sulfuric acid, both of which dissolve easily in water. The resulting acidic water droplets can be carried long distances by prevailing winds, returning to Earth as acid rain, snow, or fog.

1. Global warming is caused due to Increased concentration of CO₂ in air.

2. Burning of coal and diesel releases SO₂. 

3. Petrol engine gives off gaseous oxides of Nitrogen.

4. Acid rain is caused by oxides of Sulphur, nitrogen.

5. The Stratosphere is the layer of the atmosphere that contains the protective ozone layer.

6. Chemicals intended to kill insects and other organisms that damage crops called Pesticides.

1. True

2. True

3. False, 

it can also affect our lungs—its can make it harder to breathe, and make asthma worse.

4. True

A bio-fertilizer is Anabaena.

The substance which on adding to the environment may cause harm is called pollutant.

Effects of Acid Rain:

1. Acid rain increases acidity in the soil and destroys forests and crops.

2. It corrodes fences, buildings, monuments, bridges and statues.

3. It affects the human nervous system by causing neurological diseases.

4. It poses a serious threat to human health, since it contaminates air and water.

Acid rain is the term for pollution caused by sulphur and nitrogen dioxide when they combine with atmospheric moisture.

Smog is a combination of smoke and fog.

1. Rain that is more acidic than normal is called Acid rain.

2. The release of hot water into rivers causes Water Pollution.

3. Sewage is the source of Fresh Water pollution.

4. Drinking polluted water causes diseases like Cholera and dysentery.

5. Noise pollution causes Hearing impairment and Hypertension.

6. Chlorofluorocarbons is manmade compounds that have been widely used as refrigerants and in spray propellants and foam blowing.

False. 

(When water is mixed with natural or artificial unwanted material, the dissolved oxygen level of such water decreases. This causes harm to the resident animals. However when aquatic weeds and algae outgrow in number it causes rise in oxygen only during day time.)

1. True

2. False, 

These are organic pollutants.

3. False, 

Some pollutants are odourless and colourless such as ozone.

4. True

1. Effects of air pollution on animals:

• Air pollutants affect breathing of the animals. 
• Particulate pollutants can cause problems to the wildlife. 
• Particulate matter containing heavy metals is accumulated in the bodies of animals. The accumulated heavy metals at high levels in the body tissues, can cause problems.
• Acid rain causes serious problems to animal life.

2. Effects of air pollution on plants:

• Various parts of the plant show reduced growth after coming in contact with air pollutants. 
• The leaves show yellowing or chlorosis on exposure to air pollutants.

The micro organisms which when added to the soil increase the fertility of the soil, are termed as Biofertilizer.

SO₂/NO mainly contribute to acid rain.

Acid rainfall is involved with the increased in rivers, destroying aquatic animals.

Any organic material of plant or animal source which when added to soil improves its quality to raise better crops is called manure.

(i) Atomic explosion (All others are natural causes of air pollution.)

(ii) Sulphur (All others are elements which are used in the production of atomic energy.)

The unit to measure sound is called decibel.

Chloro fluro carbons/CFCs

(i) Dust storms (All others are man-made causes environmental degradation.)

(ii) Silicosis (All others are effects of methane.)

(iii) Mental weakness (All other are effects of sulphur dioxide.)

Carbon monoxide

The process of breaking down of proteins into ammonia is called Ammonification.

False. 

(The toxic substances added to the soil can leach in the groundwater and cause water pollution.)

1. Ozone layer depletion is mainly caused due to the action of CFC (Chlorofluorocarbon) molecules in the air.

2. Due to various increased activities of humans, the magnitude of air pollution has been increasing in the last few decades. 

3. CFC molecules were used as coolants in refrigerators, freezers and air conditioners. 

4. They were also present in industrial solvents, dry cleaning agents and hospital sterilants, aerosols and foam. Due to such enhanced use, much of the CFCs were liberated in the last few years. 

5. CFC molecules are decomposed by ultraviolet rays which release chlorine and fluorine molecules. 

6. Chlorine and fluorine react with the ozone resulting in a hole in the ozone layer present in the stratosphere.

Therefore, a hole has been observed in the ozone layer in the stratosphere above Antarctica.

Number of three Oxygen atom in Ozone. 

The process of converting, ammonia into nitrite and nitrates, is called Nitrification.

Ozone is present in large amount in the upper part of stratosphere.

(i) Carbon dioxide

(ii) Methane

(iii) Nitrogen oxide

Radioactive pollution is caused by cosmic radiation from space, use of radioactive materials which are used in radioactive weapons, nuclear fuel, and electric power. Radioactive pollutants remain unperished for a long period, so these are more harmful to spoil natural environment. Int modem age, it has become very difficult to survive in the natural state due to a production of various radioactive materials for various purposes.