1. Environmental Pollution

• Definition

. Cause, effects and control measures of:-

A. Air pollution

B. Water pollution

C. Soil pollution

D. Marine pollution

E. Noise pollution

F. Thermal pollution

G. Nuclear hazards

• Solid waste Management: Causes, effects and control measures of urban and industrial

wastes.

• Role of an individual in prevention of pollution.

• Pollution case studies.

• Disaster management: floods, earthquake, cyclone

What are environmental pollution and its types?

Pollution

Definition: Pollution is the effect of undesirable changes in our surroundings that have harmful

effects on plants, animals and human beings. Pollutants include solid, liquid or gaseous

substances present in greater than natural abundance produced due to human activity, which

have a detrimental effect on our environment.

Pollution is defined as an addition or excessive addition of certain materials to the physical

environment (water, air and lands), making it less fit or unfit for life.

Pollutants

Classifications

According to the form in which they persist after release into the environment

1. Primary pollutants: These persist in the form in which they are added to the

environment e.g. DDT, plastic.

2. Secondary Pollutants: These are formed by interaction among the primary pollutants.

For example, peroxyacetyl nitrate (PAN) is formed by the interaction of nitrogen oxides and

hydrocarbons.

According to their existence in nature

1. Quantitative Pollutants: These occur in nature and become pollutant when their

concentration reaches beyond a threshold level. E.g. carbon dioxide, nitrogen oxide.

2. Qualitative Pollutants: These do not occur in nature and are man-made. E.g.

fungicides, herbicides, DDT etc.

According to their nature of disposal

1. Biodegradable Pollutants: Waste products, which are degraded by microbial action.

e.g. sewage.

2. Non-biodegradable Pollutants: Pollutants, which are not decomposed by microbial

action. e.g. plastics, glass, DDT, salts of heavy metals, radioactive substances etc.,

According to origin

1. Natural

2. Anthropogenic

Causes of pollution

#. Uncontrolled growth in human population

#. Rapid industrialization

#. Urbanization

#. Uncontrolled exploitation of nature.

#. Forest fires, radioactivity, volcanic eruptions, strong winds etc.

Different kinds of pollution that affect the environment are:

1. Air pollution, 2. Water pollution, 3. Soil pollution, 4. Marine pollution, 5. Noise pollution,

6. Thermal pollution and 7.Nuclear hazards.

Air Pollution

Air pollution is an undesirable and excessive addition of foreign materials to air which

adversely alters its natural quality. Air pollution occurs due to the presence of undesirable

solid or gaseous particles in the air, in quantities that are detrimental to human health or which

could cause damage to plants and materials.

The substances that cause air pollution are called pollutants. Pollutants pumped into the

atmosphere and directly pollute the air are called primary pollutants. Carbon monoxide and

sulphur dioxide are the examples of primary pollutants emitted from vehicular exhausts and

combustion of coal, respectively. Further pollution can arise if primary pollutants in the

atmosphere undergo chemical reaction. The resulting compounds are called secondary

pollutants. Photochemical smog is an example of secondary pollutant.

Air Pollutants

They are the substances which pollute the air. Some of the common pollutants are dust, soot,

ash, carbon-monoxide, excess of carbon dioxide, sulphur dioxide, oxides of nitrogen,

hydrocarbons, chlorofluorocarbons (CFC), lead compounds, asbestos dust, cement dust,

pollens and radioactive rays.

Any gas could qualify as pollution if it reached a high enough concentration to do harm.

Theoretically, that means there are dozens of different pollution gases. In practice, about ten

different substances cause most concern:

Carbon monoxide (CO)

• It is a colourless, odourless gas that is produced by the incomplete burning of carbon-

based fuels including petrol, diesel, and wood.

• It is also produced from the combustion of natural and synthetic products such as

cigarettes.

• It lowers the amount of oxygen that enters our blood.

• It can slow our reflexes and make us confused and sleepy

• This highly dangerous gas forms when fuels have too little oxygen to burn completely.

It spews out in car exhausts and it can also build up to dangerous levels inside your home if

you have a poorly maintained gas boiler, stove, or fuel-burning appliance. (Always fit a carbon

monoxide detector if you burn fuels indoors).

Carbon dioxide (CO2)

• This gas is central to everyday life and isn't normally considered a pollutant: we all

produce it when we breathe out and plants such as crops and trees need to "breathe" it in to

grow. However, carbon dioxide is also a greenhouse gas released by engines and power plants.

• Since the beginning of the Industrial Revolution, it's been building up in Earth's

atmosphere and contributing to the problem of global warming and climate change.

• It is the principle greenhouse gas emitted as a result of human activities such as the

burning of coal, oil, and natural gases.

Sulphur dioxide (SOX)

• Coal, petroleum, and other fuels are often impure and contain sulphur as well as organic

(carbon-based) compounds.

• When sulfur (spelled "sulphur" in some countries) burns with oxygen from the air,

sulphur dioxide (SO2) is produced.

• Coal fired power plants are the world's biggest source of sulfur-dioxide air pollution,

which contributes to smog, acid rain, and health problems that include lung disease.

• Some industrial processes, such as production of paper and smelting of metals, produce

sulphur dioxide.

• It is a major contributor to smog and acid rain.

• Sulfur dioxide can lead to lung diseases.

Nitrogen oxides (nox)

• Nitrogen dioxide (NO2) and nitrogen oxide (NO) are pollutants produce as an indirect

result of combustion, when nitrogen and oxygen from the air react together.

• Nitrogen oxide pollution comes from vehicle engines and power plants, and plays an

important role in the formation of acid rain, ozone and smog.

• Nitrogen oxides are also "indirect greenhouse gases" (they contribute to global warming

by producing ozone, which is a greenhouse gas).

• It causes smog and acid rain. It is produced from burning fuels including petrol, diesel,

and coal.

• Nitrogen oxide can make children susceptible to respiratory diseases in winters.

Volatile organic compounds (VOCs)

• These carbon-based (organic) chemicals evaporate easily at ordinary temperatures and

pressures, so they readily become gases.

• They're used as solvents in many different household chemicals such as paints, waxes,

and varnishes. Unfortunately, they're also a form of air pollution: they're believed to have long-

term (chronic) effects on people's health and they also play a role in the formation of ozone and

smog.

Particulates Matter

• These are the sooty deposits in air pollution that blacken buildings and cause breathing

difficulties.

• Particulates of different sizes are often referred to by the letters PM followed by a

number, so PM10 means soot particles of less than 10 microns (10 millionths of a meter or

10µm in diameter).

• In cities, most particulates come from traffic fumes.

• It consists of solids in the air in the form of smoke, dust, and vapour that can remain

suspended for extended periods and is also the main source of haze which reduces visibility.

• The finer of these particles, when breathed in can lodge in our lungs and cause lung

damage and respiratory problems.

Ozone

• Also called trioxygen, this is a type of oxygen gas whose molecules are made from

three oxygen atoms joined together (so it has the chemical formula O3), instead of just the two

atoms in conventional oxygen (O2).

• In the stratosphere (upper atmosphere), a band of ozone ("the ozone layer") protects us

by

screening out harmful ultraviolet radiation beaming down from the Sun.

• At ground level, it's a toxic pollutant that can damage health. It forms when sunlight

strikes a cocktail of other pollution and is a key ingredient of smog.

• It occurs naturally in the upper layers of the atmosphere.

• This important gas shields the earth from the harmful ultraviolet rays of the sun.

• However, at-the ground level, it is a pollutant with highly toxic effects.

• Vehicles and industries are the major source of ground-level ozone emissions.

• Ozone makes our eyes itch, burn, and water. It lowers our resistance to cold and

pneumonia.

Chlorofluorocarbons (CFCs)

• Once thought to be harmless, these gases were widely used in refrigerators and aerosol

cans until it was discovered that they damaged Earth's ozone layer.

• These are gases that are released mainly from air-conditioning systems and

refrigeration.

• When released into the air, CFCs rise to the stratosphere, where they come in contact

with few other gases, which lead to a reduction of the ozone layer that protects the earth from

the harmful ultraviolet rays of the sun.

Unburned hydrocarbons

• Petroleum and other fuels are made of organic compounds based on chains of carbon

and hydrogen atoms.

• When they burn properly, they're completely converted into carbon dioxide and water;

when they burn incompletely, they can release carbon monoxide or float into the air in their

unburned form, contributing to smog.

Lead and heavy metals

• Lead and other toxic "heavy metals" can be spread into the air either as toxic compounds

or as aerosols (when solids or liquids are dispersed through gases and carried through the air

by them) in such things as exhaust fumes and the fly ash (contaminated waste dust) from

incinerator smokestacks.

• It is present in petrol, diesel, lead batteries, paints, hair dye products, etc.

• Lead affects children in particular. It can cause nervous system damage and digestion

problems and, in some cases, cause cancer.

Secondary Pollutant Smog

• The term smog was first used (1905) by Dr HA Des Voeux.

• Smog has been coined from a combination of the words fog and smoke.

• Smog is a condition of fog that had soot or smoke in it.

• The Formation of Smog - Photochemical smog (smog) is a term used to describe air

pollution that is a result of the interaction of sunlight with certain chemicals in the atmosphere.

• One of the primary components of photochemical smog is ozone.

• While ozone in the stratosphere protects earth from harmful UV radiation, ozone on the

ground is hazardous to human health.

• Ground-level ozone is formed when vehicle emissions containing nitrogen oxides

(primarily from vehicle exhaust) and volatile organic compounds (from paints, solvents,

printing inks, petroleum products, vehicles, etc.) interact in the presence of sunlight.

Smog refers to hazy air that causes difficult breathing conditions. It is a combination of various gases with water vapour and dust.

Its occurrences are often linked to heavy traffic, high temperatures, and calm winds. During the winter, wind speeds are low· and cause the smoke and fog to stagnate near the ground; hence pollution levels can increase near ground level.

Smoke particles trapped in the fog gives it a yellow/black colour and this smog often settled over cities for many days.

The effects of smog

• It hampers visibility and harms the environment

• It causes respiratory problems

• It results in deaths relating to bronchial diseases.

• Heavy smog greatly decreases ultraviolet radiation.

• Heavy smog results in the decrease of natural vitamin D production leading to a rise in

the cases of rickets.

Indoor air pollution

It refers to the physical, chemical, and biological characteristics of air in the indoor

environment within a home, or an institution or commercial facility.

Indoor air pollution is a concern where energy efficiency improvements sometimes make

houses relatively airtight, reducing ventilation and raising pollutant levels.

Indoor air problems can be subtle and do not always produce easily recognized impacts on

health. Different conditions are responsible for indoor air pollution in the rural areas and the

urban areas.

(a) Rural

It is the rural areas that face the greatest threat from indoor pollution, where people rely on

traditional fuels such as firewood, charcoal, and cow dung for cooking and heating.

Burning such fuels produces large amount of smoke and other air pollutants in the confined

space of the home, resulting in high exposure.

Women and children are the groups most vulnerable as they spend more time indoors and are

exposed to the smoke.

Although many hundreds of separate chemical agents have been identified in the smoke from

biofuels, the four most serious pollutants are particulates, carbon monoxide, polycyclic organic

matter, and formaldehyde.

(b) Urban

In urban areas, exposure to indoor air pollution has increased due to a variety of reasons, such

as construction of more tightly sealed buildings, reduced ventilation, the use of synthetic

materials for building and furnishing and the use of chemical products, pesticides, and

household care products.

Other than nitrogen dioxide, carbon monoxide, and lead, there are a number of other pollutants

that affect the air quality.

Effects of air pollution on living organisms

The effects of air pollution can be broadly divided into three categories as given below:

• Effects on Human Beings

• Effects on Fauna and Flora

• Effects on Environment and Atmosphere.

Air Pollution: Effects on Human beings

1. Unavailability of fresh and healthy air – It is our right to live in fresh and clean air. Air

pollution is deteriorating the quality of air. Due to growing air pollution, it is difficult to find

fresh, clean and healthy air.

2. Pulmonary and respiratory diseases – Air pollution causes chronic diseases such as

COPD (Chronic obstructive pulmonary disorder) which is a complicated pulmonary disease.

The rising air pollution also causes many respiratory diseases like asthma, bronchitis, lung

cancer, etc.

3. Allergies – There are many strong and enough evidence which point towards the fact

that air pollution worsen the conditions of various allergies. For example, respiratory diseases

like asthma get triggered up when an asthmatic person comes in contact with air pollution.

Also, frequent coughing and sneezing are also common allergies that are caused by air

pollution.

4. Cardiovascular and heart diseases – Arteries blockage, heart failure, occlusion, etc., are

some of the many heart diseases that get triggered due to air pollution.

5. Poor immune system in humans – Apart from aggravating heart diseases and respiratory

diseases, air pollution also weakens our immunity system. The constant invasions of air

pollution on our lung, respiratory system, heart and other parts of the body result in poor

immunity.

6. Growing hair fall problems – Air pollution has worsened the condition of our hair. Dull

hair, grey hair, weak hair and falling hair are some of the major hair fall problems that are

associated with air pollution.

7. Early signs of age and dull skin – Air pollution are not only destroying our health, but

our beauty too! Early signs of age like wrinkles, fine lines, and dark circles appear more early

when there is a continuous exposure to air pollution.

Air Pollution: Effects on Fauna and Flora

1. Damage to Fauna – Air pollution harms animals and wildlife in many ways. The

increased ozone level in atmosphere damages the lung tissues in animals. Air pollution also

produces acid rain that results in leaching of aluminum from the soil, thus, killing the fish. The

harmful particulate particles suspended in the air affects the respiratory, circulatory and

nervous system of the animals. Even the migration cycle of birds and animals get disturbed due

to air pollution as smog creates confused vision for them.

2. Damage to Flora – Plants also get affected from air pollution through different ways

including eutrophication, acid rain and ozone at lower atmospheric levels, etc. While acid rain

makes the soil poisonous and adversely affects the growth and survival of plants, the ground

level ozone causes respiratory problems in plants by blocking the stomata in plants.

3. Adverse effects on flowering quality of plants – Air pollution also affects the flowering

quality of plants. Due to cement dust and other pollutants in the air, crusts are formed on the

flowers, giving them a poor quality and look. Moreover, the plants do not get to grow well in

excessive air pollution and give poor flowering results.

4. Effect on agriculture – Increased levels of chlorine, ammonia, ethylene, carbon

monoxide, and other harmful gases are putting food crops in danger. The decreased food crop

and poor quality of crop are also results of air pollution. The harmful effects of air pollution

can be observed on the leaves, roots, flowers and fruits of plants.

Air Pollution: Effect on Environment and Atmosphere

1. Depleting ozone layer – One of the most dangerous effects of air pollution is depleting

ozone layer. Ozone layer protects us from harmful ultraviolet (UV) rays of sun. The

chlorofluorocarbons or the CFC, present in air due to air pollution are damaging the ozone

layer. The results of dangerous UV radiation can be seen in the form of skin cancer, eye diseases

and many other problems.

2. Global warming – Various air pollutants and effects like depleted ozone layer,

greenhouse gases, etc., are together forming the problem of global warming. Due to global

warming, the temperature of Earth’s atmosphere is increasing continuously. Air pollution has

formed a cover around the atmosphere and this cover is capturing the unnecessary heat that

would otherwise release from our planet.

3. Acid Rain – Acid rain is also a dangerous effect of air pollution on flora, fauna and

environment. Just as the name suggests, acid rain is a rain, which is acidic in nature. It is caused

by air pollution when processes like burning of coal, fossil fuels, etc., produce harmful gases

that mix up with natural precipitation and make soil and water poisonous.

4. Harmful effects of smog – Smog is excessive and strong fog that surrounds Earth’s

atmosphere. Smog is actually a mixture of different types of air pollutants. Smog actually forms

from smoke and fog. Smog affects plants, animals and humans in various ways by causing

problems like respiratory diseases, lung diseases, disturbed migration cycle of birds/ animals

and other problems too!

Effects of air pollution on materials

Air pollutants break down the exterior paint on cars and houses. All over the world, air

pollutants have discoloured irreplaceable monuments, historic buildings, marble statues, and

other heritage and natural beauty sites.

Effects of air pollution on the stratosphere

Ozone layer is a deep layer in earth’s atmosphere that contain ozone which is a naturally

occurring molecule containing three oxygen atoms. These ozone molecules form a gaseous

layer in the Earth’s upper atmosphere called stratosphere. This lower region of stratosphere

containing relatively higher concentration of ozone is called Ozonosphere. The Ozonosphere

is found 15-35 km (9 to 22 miles) above the surface of the earth. The concentration of ozone

in the ozone layer is usually under 10 parts per million while the average concentration of ozone

in the atmosphere is about 0.3 parts per million. The thickness of the ozone layer differs as per

season and geography. The highest concentrations of ozone occur at altitudes from 26 to 28 km

(16 to 17 miles) in the tropics and from 12 to 20 km (7 to 12 miles) towards the poles.

The ozone layer forms a thick layer in stratosphere, encircling the earth, which has large

amount of ozone in it. The ozone layer protects life on earth from strong ultraviolet radiation

that comes from the sun. Ultraviolet rays are harmful rays that can drive up the risk of deadly

disorders like skin cancer, cataracts and damage the immune system. Ultraviolet rays are also

capable of destroying single cell organism, terrestrial plant life, and aquatic ecosystems.

The total amount of ozone in a ‘column’ of air from the earth’s surface upto an altitude of 50

km is the total column ozone. This is recorded in Dobson Units (DU), a measure of the

thickness of the ozone layer by an equivalent layer of pure ozone gas at normal temperature

and pressure at sea level. This means that 100

DU=1mm of pure ozone gas at normal temperature and pressure at sea level.

Air Pollution in India, Air quality Monitoring and Legal aspects of Air pollution in India:

READ FROM BOOK ERACH BHARUCHA

Ozone Layer Depletion

Ozone layer depletion is one of the most serious problems faced by our planet earth. It is also

one of the prime reasons which are leading to global warming. Ozone is a colourless gas which

is found in the stratosphere of our upper atmosphere. The layer of ozone gas is what which

protects us from the harmful ultraviolet radiations of the sun. The ozone layer absorbs these

harmful radiations and thus prevents these rays from entering the earth’s atmosphere.

Ultraviolet radiations are high energy electromagnetic waves emitted by the sun which if enters

the earth’s atmosphere can lead to various environmental issues including global warming, and

also a number of health related issues for all living organisms. Thanks to the ozone layer which

protects us from these harmful rays.

From the 1970s the depletion of the ozone layer started to capture the attention of the scientists,

environmentalists, and the world community at large. There had been a lot of research on this

topic over these years to find out all the possible causes that lead to this problem and the effects

of ozone depletion. There has been also a lot of research to find out possible solutions to this

problem. Let us see some of the important causes and effects of ozone layer depletion.

Causes of ozone layer depletion

The main things that lead to destruction of the ozone gas in the ozone layer. Low temperatures,

increase in the level of chlorine and bromine gases in the upper stratosphere are some of the

reasons that leads to ozone layer depletion. But the one and the most important reason for ozone

layer depletion is the production and emission of chlorofluorocarbons (CFCs). This is what

which leads to almost 80 percent of the total ozone layer depletion.

There are many other substances that lead to ozone layer depletion such as hydro

chlorofluorocarbons (HCFCs) and volatile organic compounds (VOCs). Such substances are

found in vehicular emissions, by-products of industrial processes, aerosols and refrigerants. All

these ozone depleting substances remain stable in the lower atmospheric region, but as they

reach the stratosphere, they get exposed to the ultra violet rays. This leads to their breakdown

and releasing of free chlorine atoms which reacts with the ozone gas, thus leading to the

depletion of the ozone layer.

Effects of ozone layer depletion

Let us see a few possible effects of the ozone layer depletion on the earth’s environment and

also on the plants and animals. The depletion of ozone layer allows entering of UV rays from

sun into the earth’s atmosphere which is associated with a number of health related and

environmental issues. Let us see its major impacts on human beings

Skin Cancer: exposure to UV rays from sun can lead to increased risk for developing of several

types of skin cancers. Malignant melanoma, basal and squamous cell carcinoma are the most

common cancers caused by exposure to UV rays.

Eye Damage: UV rays are harmful for our eyes too. Direct exposure to UV rays can lead to

Cataract problems, and also Photokeratitis or snow blindness.

Damage to Immune system: our immune system is also highly vulnerable to UV rays.

Increased exposure to UV rays can lead to weakening of the response of immune system and

even impairment of the immune system in extreme cases.

Aging of skin: exposure to UV rays can lead to acceleration of the aging process of your skin.

This will result in you looking older than what you actually are. It can also lead to photo allergy

that result in outbreak of rashes in fair skinned people

In humans, exposure to UV rays can also lead to difficulty in breathing, chest pain, and throat

irritation and can even lead to hampering of lung function.

UV rays affect other life forms too. It adversely affects the different species of amphibians and

is one of the prime reasons for the declining numbers of the amphibian species. UV rays also

have adverse effect on the marine ecosystem. It adversely affects the planktons (small plants

and animals) which plays a vital role in the food chain and oceanic carbon cycle. Affecting

phytoplankton will in turn affect the whole ocean ecosystem. UV rays will also affect the

plants.

UV radiations can alter the time of flowering in some plant species.

Ozone layer depletion leads to decrease in ozone in the stratosphere and increase in ozone present

in the lower atmosphere. Presence of ozone in the lower atmosphere is considered as a pollutant

and a greenhouse gas. Ozone in the lower atmosphere contributes to global warming and climate

change. The depletion of ozone layer has trickle down effects in the form of global warming, which

in turn leads to melting of polar ice, which will lead to rising sea levels and climatic changes

around the world.

Ways to bring down ozone layer depletion

Ozone layer depletion is not something that affects any specific country or region. The whole

world is vulnerable to its after effects. That makes it important for each and every one of us to take

actions to reduce ozone layer depletion. International agreements such as Montreal protocol in

1987 have helped in reducing and controlling industrial emission of Chlofluorocarbons. More and

more of such international agreements between countries is necessary to bring down ozone layer

depletion. At individual level each and every one also can contribute towards reducing ozone layer

depletion. Buying and using recycled products, saving of energy, using of public transport can do

a lot in combating ozone layer depletion. The most important thing that we can do is spreading

awareness. Our individual efforts will go a long way in saving the earth’s blanket and keep our

planet earth liveable for us and our future generations.

Control Measures

1. Policy measures

2. Preventive measures:

• Selection of suitable fuel (e.g. fuel with low sulphur content) and its efficient utilization

• Modifications in industrial processes and/or equipment’s to reduce emission.

• Selection of suitable manufacturing site and zoning. E.g. setting of industries at a distance

of residential areas, installation of tall chimneys.

Control measures:

(a) Destroying the pollutants by thermal or catalytic combustion

(b) Conversion of the pollutants to a less toxic

(c) Collection of the pollutant

Different types of air pollutants can be eliminated/ minimised by following methods:

a) Control of particulate matter: Two types of devices - arresters and scrubbers are used to

remove particulate pollutants from air.

A) Arresters: These are used to separate particulate matters from contaminated air.

B) Scrubbers: These are used to clean air for both dusts and gases by passing it through a dry

or wet packing material.

b) Control of Gaseous Pollutants: The gaseous pollutants can be controlled through the

techniques of Combustion, absorption and adsorption.

c) Control of Automobile Exhaust

I. Use of efficient engines (e.g. multipoint fuel injection engine).

II. Catalytic converter filters in the vehicles can convert nitrogen oxide to nitrogen and reduce

the potential hazards of NOx.

III. Use of good quality automobile fuels

IV. Use of lead free petrol.

V. Use of compressed natural gas (CNG).

Government Initiatives

(1) National Air Quality Monitoring Programme

• In India, the Central Pollution Control Board (CPCB) has been executing a nationwide

programme of ambient air quality monitoring known as National Air Quality Monitoring

Programme (NAMP).

• The National Air Quality Monitoring Programme (NAMP) is undertaken in India

I. to determine status and trends of ambient air quality;

II. to ascertain the compliance of NAAQS;

III. to identify non-attainment cities;

IV. to understand the natural process of cleaning in the atmosphere; and

V. to undertake preventive and corrective measures.

• Annual average concentration of SOx levels are within the prescribed National Ambient

Air Quality Standards (NAAQS).

• This reduction from earlier levels is due to various measures taken, including the use of

CNG in public transport in Delhi, the reduction of sulphur in diesel and use of LPG instead of coal

as a domestic fuel.

• A mixed trend is observed in NO2 levels due to various measures taken for vehicular

pollution control, such as stricter vehicular emission norms being partially offset by increased NOx

levels due to the use of CNG in urban transport.

• Total suspended particulates, however, are still a matter of concern in several urban and

semi urban areas.

(b) National Ambient Air Quality Standards (NAAQS)

National Ambient Air Quality Standards (NAAQS) were notified in the year 1982, duly revised in

1994 based on health criteria and land uses.