03 Other major types of Environmental Pollution

Analytical Chemistry

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Environmental Analysis

Other major types of Environmental Pollution

Paper No. : 15 Environmental Analysis

Module : 03 Other major types of Environmental Pollution

Principal Investigator: Dr.Nutan Kaushik, Senior Fellow The Energy and Resources Institute (TERI), New Delhi

Co-Principal Investigator: Dr. Mohammad Amir, Professor of Pharm. Chemistry, JamiaHamdard University, New Delhi

Paper Coordinator: Dr. Nimisha Jadon, Assistant Professor, School of Studies in Environmental Chemistry, Jiwaji University, Gwalior

Content Writer: Dr. Nimisha Jadon, Assistant Professor, School of Studies in Environmental Chemistry, Jiwaji University, Gwalior

Content Reviwer: Prof. Rajeev Jain, Professor of Chemistry, Jiwaji

University, Gwalior


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Description of Module

Subject Name Analytical Chemistry / Instrumentation

Paper Name Environmental Analysis

Module Name/Title Other major types of Environmental pollution

Module Id 03

Pre-requisites

Objectives

Keywords


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Soil Pollution

The area of earth which is capable of supporting life is presented by a thin mantle

and there is a very complex relationship between this land and the other components

of the environment.

Man and other animal and there sources of a given area and so natural forces cannot

maintain the balance between the material consumed and returned to the soil.

Soil pollution is defined as the contamination of the soil system by considerable

quantities of chemical or other substances, resulting in the reduction of its fertility

(or productivity) with respect to the qualitative and quantitative yield of the crop.

However, if some of the contaminants are such that if they are taken up by the

plants (with or without any detrimental effects on the plants).Chain and impart

detrimental/ toxic effect on the consumers (i.e. animals .and human beings), then that should

also be treated as soil pollution.

The soil gets polluted by the following ways:

1. By Agricultural Practices: Agricultural wastes are common pollutants of soil as well as

water pollution. Agro-chemicals such as' fertilizers, pesticides, insecticides and

weedicides cause soil pollution. -DDT, BHC, etc. and chemicals like lead, mercury,

arsenic, etc. accumulate in the soil permanently. Soil pollution resulting from excessive

use of insecticides, herbicides and fertilizers adversely affect the physical, chemical and

biological properties of soil.


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2. By Radioactive Materials: Radioactive substances resulting from explosion of nuclear

devices also penetrate the soil and enter into food chain. The presence of radioactive

substances causes many harmful effects in body tissues. Radioactive radiations also bring

about changes through mutation and can cause death of organisms.

3. By Biological Agent: Other important pollutants are the biological agents including

various biological organisms from human and animal excreta. In addition to excreta, faulty

sanitation, waste water disposed etc. includes land as well as soil pollution. These also spread

various diseases. Household refuse, Industrial water, Agricultural wastes are tipped on land.

By these many chemicals undecided substances enter into surface and get mixed with ground

water. These chemicals are harmful for living beings and affect plant and animals' growth.

Soil Pollutants:

Natural and synthetic materials that can adversely affect the physical, chemical and

biological properties of soil and seriously affect its productivity are called soil pollutants and

this phenomenon is called soil pollution.

The problem of soil pollution differs from air and water pollution in the respect that the

pollutants remain in direct contact with the soil for relatively longer periods.

The widespread industrialization and increasing consumption have changed the very

complexion of soil. Thus the soil is getting heavily polluted day by day by toxic material and

dangerous microorganisms which enter the air, water and food chain. For all this, man is the

original and basic pollutant responsible for pollution hazards and toxic effects.


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Causes of Land Pollution

Sources of Soil Pollution Soil pollution mainly results from the following sources:

1. Industrial wastes

2. Urban wastes

3. Radioactive pollutants

4. Agricultural practices

5. Chemical and metallic pollutant

6. Biological agent.

1. By Industrial wastes. Disposal of industrial waste is the major reason for soil

pollution. These industrial pollutants are mainly discharged from pulp and paper

mills, chemical industries, oil refineries, sugar factories, tanneries, textiles, steel

industries, distilleries, coal and mineral mining industries, drugs, glass, cement,

petroleum industries etc. Thermal; atomic and electric power plants are also the

villain to add pollutants to the soil. Fly ash, many industrial effluents are either

discharged into streams or dumped into the surrounding land: Industrial wastes

mainly consist of organic compounds along with inorganic complexes and non

biodegradable materials. The pollutants affect and alter the chemical and biological

properties of soil.

2. By urban wastes. Urban wastes comprise both commercial and domestic wastes

consisting of dried sludge of sewage. All the urban solid wastes are commonly

referred to as refuse. Solid wastes and refuse contribute to soil pollution. This

contains garbage and rubbish materials like plastics, glasses, metallic cans, fibers,

paper, rubbles, street sweepings, fuel residues, leaves, containers, abandoned vehicles

-and other discarded manufactured products. Pollution concentration in urban areas


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and unplanned industrial progress has to a greater extent contributed to soil pollution

problems,

3. Radioactive pollutants: Radioactive substances resulting from explosions of

nuclear devices, atmospheric fallout from nuclear dust and radioactive wastes

penetrate the soil and accumulate there creating soil pollution. Radioactive substances

Radium, Thorium, Uranium, Carbon (C-14) are very common in soil, rock, water and

air. The product of nuclear fission, rain water (Sr-90, Cs:'137) to be deposited on the

soil emit gamma radiation.

Recently it has been indicated that some plants such as lichen and mushroom can

accumulate Cs-137 and other radio nuclides which concentrate in grazing animals.

3. Agricultural Practices. Agricultural practices pollute the soil to a large extent.

Advanced Agro-technology, huge quantities of fertilizers, pesticides, herbicides,

weedicides and soil conditioning agents are employed to increase the crop yield. Many

agricultural lands have now-excessive amounts of plants and animals wastes which are

posing soil pollution problems: Farm wastes, manure slurry, debris, and soil erosion

'containing mostly inorganic chemicals are responsible for soil pollution.

Some of the agents responsible for this pollution are as follows: (a) Fertilizers. Fertilizers

are the chemical compounds that contain one or more of the plant nutrients i.e., nitrogen,

phosphorous and potassium. Excessive use of fertilizers makes soil pollutated.

Fertilizers are retained by the soil and crop efficiently but there are some possibilities for

the nitrates to be washed out due to negligence and appliances in applying fertilizers to


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arable lands. These nitrates cause several undesirable effects on the water quality of low

land lakes or rivers creating numerous health hazards. (b) Pesticides. By growing

population density it is necessary to increase food production. Due to this it led to

manipulation of land resources. Different kinds of pesticides used to control pests are

causing a stress in the natural environment. With the increasing use of pesticides it is

observed that pesticide residues coexist within biological system with other forms of life.

(c) Soil conditioners and other chemical agents. In addition to the fertilizers, pesticides

and biocides, soil conditioners and fumigants are also employed to the land system to

increase and protect the soil. Fertility, to kill the hazardous insects. These chemical

agents are reported to cause alterations in both agricultural and horticultural soil areas.

They contain several toxic metals such as Pb, As, Cd, Hg, Co etc. which When applied to

a land will accumulate on the soil permanently thereby introducing these chemical

components into growing crops. (d) Farm Wastes. Increasing population of cow, cattles

etc. have resulted in Considerable soil pollution. Buildings in which grazing animals are

housed can be cleaned using water but the manure is also washed out and deposited as

wet slurry on the land. This slurry deposited on soil may seep into ground water and

pollute it. Cattles faecal matter mainly consists of phosphates which in conjunction with

nitrate cause numerous undesirable effects in the soil texture.

(5) Chemical and metallic pollutants: A number of industries including textiles, dyes,

soap and synthetic detergents, drugs, cement, rubber, paper and pulp etc. and metal

industries pour their hazardous effluents in soil and water creating disastrous effects on

living organisms. Synthetic chemicals and fertilizers are as source of trace metals which

are added to the soil either deliberately or as an impurity. In many soils 50to 100%of soil

carbon is found complexed with clay containing organic and inorganic components

which affect the soil texture, its fertility and stabilization of soil organic matter.·


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(6)Biological Agents: Soil gets large quantities of human, animals and birds excreta

which constitute the major source of land pollution by biological agents. Digested

sewage sludge as well as heavy application of manures to soil without periodic leaching

could cause chronic salt hazard to plants within a few years. Sludges to have faults as

they contain enough live viruses and viable intestinal worms. The pathogenic organisms

that pollute the soil may be classified into three major categories: (I,) Pathoaenic

organisms occurring naturally in contaminated soil. Bacteria algae, protozons nematodes

etc. These organisms are important agents in increasing or decreasing the soil fertility, in

altering the physical texture of the soil and in attacking roots of plants. (b) Pathogenic

Organisms execrated by Man Human excreta includes pathogens such as enteric bacteria

and parasitic worm such as tenia solium. These organisms are transmitted to the man by

the consumption of vegetables or fruits. (c) Pathogenic Organisms Excreted by Animals

this category includes pathogenic bacteria and worms excreted by animals like

earthworms, millipedes, dipterous larvae, snails including higher animals carry fungal

and bacteria spores. The disease producing organisms are transmitted from animals to

soil and then from soil to man.

1. Overcrowded landfills: Each household produces tonnes of garbage each year.

Garbage like aluminum, plastic, paper, cloth, wood is collected and sent to the local

recycling unit. Items that cannot be recycled become a part of the landfills that

hampers the beauty of the city and cause land pollution.

2. Industrialization: Due to increase in demand for food, shelter and house, more goods

are produced. This resulted in creation of more waste that needs to be disposed of. To

meet the demand of the growing population, more industries were developed which


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led to deforestation. Research and development paved the way for modern fertilizers

and chemicals that were highly toxic and led to soil contamination.

3. Nuclear waste: Nuclear plants can produce huge amount of energy through nuclear

fission and fusion. The left over radioactive material contains harmful and toxic

chemicals that can affect human health. They are dumped beneath the earth to avoid

any casualty.

4. Other Sources. Some other sources by which soil gets polluted are:

(a) By absorption of toxic metals. (b) By soluble salts. (c) By mining. (d) By waste

water added to soil. (e) By solid waste applied to soils. By food processing wastes

(g) By sugarcane trash in field (h) By municipal garbage and composts.

Causes of Soil Pollution and their Control:

The causes of soil pollution can broadly be classified as-direct causes and indirect causes.

Direct causes include poor waste management, application of agro-chemicals, faulty

sanitation practices, salination due to irrigation and floods, and soil erosion. Indirect causes

include acid rain and disposed radioactive substances.

1. Poor Waste Management:Wastes are unwanted and useless substances

resulting from different human activities. The wastes can be solid wastes and or

liquid wastes. (i) Solid Waste and its Control. Unwanted or discarded substances

that have weight size are called solid wastes. It includes sewage sludge, domestic

and municipal solid waste, industrial solid waste and agricultural solid waste. The

waste-preventive approach, which considers solid waste as a resource, suggests

two measures reduction in solid waste, and reuse and recycling, Solid waste can

be reduced by manufacturers by using less material and redesigning

manufacturing processes. Further wastes can be reused after repairs and also can


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be recycled. For example solid waste like glass, metals, plastic, paper, etc. can be

segregated and recycled. Finally, the control of solid waste can be done by using

proper disposal methods such as composting of biodegradable solid waste,

incineration of non-biodegradable, pulverization. Sanitary land filling. etc. (ii)

Liquid Waste Control: Liquid waste from point sources, such as domestic and

industrial waste waters, not only cause water pollution but soil pollution too.

5. To control soil Pollution from these sources, municipal and Industrial waste waters

have to be properly collected, treated and disposed of scientifically in water bodies or

on lands. Proper care must be taken in treating heavy metal and other toxic waste

materials.

6. Application of Agro-Chemicals A variety of agro-chemicals such as pesticides,

insecticides and fertilizers are utilized in modem day agricultural practices for more

and more yields. Pesticides are used to control pests whereas insecticides, weedicides

are used to control insect and unwanted plants. Fertilizers are used for increasing

production of agriculture products. These chemicals are not degraded quickly.

7. Their concentration affected life and health of the man, It is important to know

environmental hazards of these chemicals and take appropriate steps to check them

out. One of the ways is the minimum use of these substances and utilising other

operations along with the use of them. Health Problems due to Agro-Chemicals (I)

Chlorinated hydrocarbons cause cancer, birth defects, neurological disorders. (il)

Most of the organic phosphates are toxic and humans may suffer from drowsiness,

diarrhoea, vomitting, air"and breathing difficulty. High concentration may cause

paralyses tremors, coma and death. (iii) Carbonates cause birth defects and genetic

damages. (iv) Food items contain residues of agro-chemicals which are harmful to our


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health. (v) Farm and chemical workers are exposed to agro-chemicals. This causes

many health problems in them

(vi) Increased concentration of agro-chemicals per unit weight of organism with the

rise in trophic level of an ecosystem is called biomagnification e.g., it is interesting to

note the manner in which DDT accumulates in the food chain. Plankton in water

contains about 0.04 ppm DDT.

8. Faulty Sanitation Practices: Sanitation means the whole field of controlling the

environment with a view to prevent disease and promote health. The term

"environmental sanitation is now being replaced by environmental health." WHO

explained environmental Sanitation as- The control of those factors in man's physical

environment which exercise or may exercise a deleterious effect on his physical

development, health and survival. Faulty methods of sanitation cause soil or land

pollution. The soil conservation depends upon proper use of methods of checking soil

pollution as a result of faulty sanitation methods. We should use methods for efficient

collection, removal and disposal of solid waste. Human secretes is a source of

infection. 4. Salination due to Irrigation and flood Water soluble salts have adverse

affect on soil productivity and degrade the quality of land as well assoil. Intensive

farming with poor drainage is causing serious salination damage in large areas of our

country.

5. Soil Erosion Soil erosion is a comprehensive natural process of detachment and

removal of loosened soil materials by oxygenation process i.e., by water, wind, ice or

gravity. In other words, erosion is the wearing away of the land surface by running

water, wind, ice or other geological agents. Soil erosion is increased due to

agricultural development, construction and strip-mining activities. There are


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numerous ways by which the fertile top layer is lost and wasted. Slow removal of the

top soil and disturbances in the soil texture is called soil erosion.

Effects of Land Pollution

Ecological changes have a direct impact on living organism. The environment has

deteriorated owing to industrial stress, urbanization, population density and numerous other

villains which make the earth as a paradise for infectious agents. Such chronically

accumulated environment contaminates our air, water, food and soil etc. thereby severely

affecting the health. Nearly 80%ofthe diseases particularly in developing world can be linked

with soil and water. About 90% of the pollution load in river system is due to faecal matter.

The soil is highly polluted by several pathogenic organisms and. hazardous industrial

effluents. Soil pollution is the result of urban-technological revolution I and speedy

exploitation of every bit of natural resources.

The harmful effect of soil pollution under following headings:

1. Effects of industrial pollutants <,) Industrial wastes consist of a variety of chemicals

which are extremely toxic to living being. Different industries release different harmful

toxins. These toxins enter in the food chain causing a number of undesirable effects. (il)

Industrial effluents when discharged through sewage system will poison the biological

purification mechanism of sewage treatment causing several soil and water-borne diseases.

(iiI) Metallic contaminants (Zn, Cd, etc.) destroy bacteria and beneficial micro organisms in

the soil. (iv) Soluble salts are responsible for cost-damage: These cause crop loss, soil loss,

metallic corrosion (v) Some of the trade wastes contain pathogenic bacteria e.g., Anthrax

bacilli bacteria from tannery wastes. 2. Effects of Urban Waste Products (,) In India million

tonnes of waste is dumped along highway and other places. These wastes spread several

chronic diseases.


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(ii) The wastes including building materials, sludge, dead animal skeletons, and thrown away

garbage pile up at public places and cause obstruction in daily life. (iii) Sewage is the good

medium for the growth of pathogenic bacteria, viruses etc. Vibrio cholera found in sewage

causes cholera.

(iv) Solid wastes result in offensive odour and cause clogging of ground water filters.

Suspended matter in sewage can blanket the soil, thereby interfering with the soil moisture.

(p) The use of polluted ground water containing human excreta, sewage sludge decrease soil

fertility by-killing micro organisms.

3. Effects of Radioactive Pollutants: The problem of radioactive wastes dumped into the

soil is more complicated. Radioactive elements can remain active in soil for long times.

Harmful effects of radioactive pollutants are:

(i) Radioactive pollutants can produce great human misery when food containing

radionuclides is taken by man, some of them concentrate in specific body organs and cause

undesirable diseases. (ii) Radiation actually affects the soil and soil fertility. These radiations

kill plant species. ; Variations in radio sensitivity among tree and shrubs are due to

differences in their chromosome number and size. (iii) A recent report indicates that a large

number of induced radio nuclides as carbon-Id, Fe-55, Mn-54, Co-57 etc. get concentrated in

biological systems. 4. Effects of Modem Agro-technology Effects of Fertilizers: (I)

Potassium fertilizers in soil decrease the valuable nutrient ascorbic acid (vitamin C) and

carotene in vegetables and fruits. (ii) Excessive use of nitrogenous fertilizers in land leads to

'accumulation of nitrate in the soil. This excess accumulation can cause diarrhoea and

cyanosis in children. (iii) Phosphate fertilizer is considered detrimental to crop production .

(iv) Cereal crops like jawar, maize etc. grown on alkaline soil absorb higher amounts of

fluorides and are responsible for thespread of fluorosis. . Effects of Pesticides: Pesticides

retained in soil concentrates in crop, vegetables etc. which contaminant them to such an


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extent that they are not usable. (ii) Pesticides like DDT, endrin etc. are known to seep

gradually through soil into ground water and contaminate drinking water supplies:

(iii) Organophosphates pesticides cause extreme muscular weakness, tremors and dizzines in

poisoned < animals. (iv) Longer lasting effects of pesticides are visible in animals and man

where they affect the tissues and interfere in the normal metabolic activities.

Diseases Caused by Soil Pollution Soil flora and fauna make the biological system of soil

complex. Some organisms also help in maintenance of soil fertility while majority of

microorganisms act as chronic pollutants. Soil has been a potential carrier of microbial

growth, non-biodegradable matters and pathogens which endanger human health and life. (I)

Pathogenic soil bacteria are (chronic disease carriers) transmitted from man to soil or vice

versa causing cholera, typhoid etc. (ii) Pathogenic soil bacterial mycobacterium, Leptospira

etc. are causes of infection of amoebic dysentery, cholera, polio, hepatitis etc," (iii) The eggs

of parasitic worms helminthes get incubated in the soil, and causes intestinal hook worm

diseases. (iv)Common viruses (polio, hepatitis) present in sewage added to soil are causes of

paralysis. (v) Some of the animals' diseases are transmissible to man and soil. Leptospirosis,

Anthrax and fever are some of diseases belonging to this category , (vi) Fungus generally

develop in soil or vegetation. They cause serious subcutaneous and systemic mycoses. (vii)

Algae poison is considered to be the most virulent poison which produces cirrhosis of liver.

Soil provides the best medium for the growth of eggs, larvae and flies etc. Many important

tropical diseases (like malaria, filariases) have blood sucking flies as vectors; while

schistomiasesis transmitted by snails states some diseases associated with pathogens present

in soil and water.


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Some Soil and Water Diseases

Pathogen Diseases 1- Salmonella choleraesuis Chronic fever 2. Lice Typhus 3. Hook worm

Skin diseases 4. Mosquitoes Urban yellow .fever 5. Anopheles mosquito Malaria fever

1. Effect on wildlife: They face a serious threat with regards to loss of habitat and

natural environment. The constant human activity on land is leaving it polluted;

forcing these species to move further away and adapt to new regions or die trying to

adjust. Several species are pushed to the verge of extinction, due to no homeland.

Other issues that we face include increased temperature, unseasonal weather activity,

acid rains etc. The discharge of chemicals on land, makes it dangerous for the

ecosystem too. These chemicals are consumed by the animals and plants and thereby

make their way in the ecosystem. This process is called bio magnification and is a

serious threat to the ecology.


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Methods to Minimize soil pollution:

The problem of soil pollution can be minimized to some extent by adopting the following

techniques: Separate garbage bins can be used to collect different varieties of wastes for

recycling purposes. (ii) Paper should not be mixed with glass or plastic which are difficult to

recycle. (iii) Encouraging the people. by ways of subsiding the waste.(iv) Tax- exemptions

are also beneficial to enhance recycling of wastes. (v) Making use of recycled paper instead

of fresh ones. For example, local administrative offices in use recycled paper to initiate reuse

of waste. (vi) By reducing the creation of waste recovering, recycling and reusing potential

wastes, the amounts of waste can be reduced effectively.

The Associated Chambers of Commerce and Industry of India (ASSOCHAM) recently have

highlighted the following suggestions to minimize and control of soil pollution.:

(I) An autonomous waste management institute should be established. The institute

could advise the Government on policy issues and evolve strategies for reducing

waste, protecting the water and soil.

(II) (ii) A national policy needs to be evolved on the management of toxic wastes. It

should aim at reducing the volume of wastes, utilizing it for manufacturing

recycled products to generate resources, treating and disposing the remaining

waste in an environmentally friendly manner.

(iii) Extending market support for recoverable products through fiscal

concessions. (iv) Common treatment and disposal facilities, where -municipal

effluent plant is not available.

(v) ECO friendly schemes and technologies should be Other Effective Measures

to Control soil Pollution (i) Operation Clean-up. (ii) Natural Band.

Water to sink into the soil rather than flow down the slope into streams and rivers.


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Recycling trees: In this technology of shrinking land fill space and growing concern about

solid waste disposal, Water carriage system is provided only for l00 of the population.

Majority of the urban and rural community is having dry conservancy system where the night

soil is collected from pail type of lavatory. Night soil thus collected is disposed of by

dumping or trenching causing soil pollution and spreading chronic diseases.


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THERMAL POLLUTION:

Thermal pollution is also commonly known as heat pollution and occurs when heat

released into water or air produces undesirable effects. Thermal pollution can be a

sudden, acute event or a long-term, chronic process. Sudden heat releases usually

occur due to natural events, i.e., forest fires and volcanoes, or due to human-induced

events, i.e., fire storms.

Causes or Sources of Thermal Pollution:

The various causes for thermal pollution are as follows: (1) Nuclear Power Plants :

Nuclear power plants including drainage from hospitals, research institutes, nuclear

experiments and explosions, emit a large amount of unutilized heat and traces of toxic

radio nuclear into nearby water streams. Emissions from nuclear reactors and

processing installations are also responsible for increasing temperature of water

bodies. (2) Coal-fired Power Plants: Some thermal power plants use coal as fuel.

Coal-fired power plants constitute the major source of the thermal pollution. (3)

Industrial Effluents: Industries Generate electricity like coal powered and nuclear

powered plants, require large amount of cooling water for heat removal. Other

industries like textile, paper, pulp and sugar industry also release heat-in water, but to

a lesser extent. (4) Domestic, Sewage: Domestic sewage is casually discharged into

rivers, lakes, canals or streams without waste treatment. The municipal water sewage

normally has a higher temperature than receiving water. With the increase in

temperature of the receiving water DO content "decreases and the demand of oxygen

increases hence the anerobic conditions will set up resulting in the release of foul and

offensive gases in water.


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(5) Hydro-Electric Power: Generation of hydro-electric power, also, sometimes

results in negative thermal loading of water systems. Industries other than electric

power industries, with cooling requirements, also contribute to the thermal pollution.

Effects of Thermal Pollution:

The release of large amounts of heated water into the river or pond or lake changes

the average water temperature and concentration of dissolved oxygen, changing the

river's species composition. Every species has an optimal temperature and a range of

temperature within which it can survive. For some species this range is very small and

slightest change in water temperature can be a problem for them. When the water

temperature rises more than 1.5°Cabove the normal, the lake fish move away while

river fish can withstand a rise in temperature upto 3°C. Higher temperature of water

can change the natural conditions and, (a) finally disturb the river ecosystem; (b) fish

spawning cycles may be disturbed; and (c) the fish may be highly susceptible to the

diseases. If warmer water causes physical stress in fish, they may be easier for the

predators to catch, and, also can change the type and availability of food for fish at

various times of the year.

Management of Thermal Pollution: The control of thermal pollution is necessary, as

its detrimental effects on aquatic ecosystem may be worse, in future. There are several

solutions to chronic thermal discharge into water bodies. Some of the viable solutions

are as follows: (1) Cooling Towers: The use of water from water source for cooling

purpose, with subsequent return to the water body after passing through the condenser

is termed as cooling process. To make the cooling process more effective, cooling

towers are designed to control the temperature of, water. Cooling towers, in fact, are

used to dissipate the recovered waste so as to eliminate the problems of thermal


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pollution. (2) Cooling Ponds. Cooling ponds/reservoirs constitute the simplest

method of controlling thermal discharges. Heated effluents on the surface of water in

cooling ponds maximize dissipation of heat-to the atmosphere and minimize the water

area and volume. It is the simplest and cheapest method which cools the water to a

considerable low temperature. But the technique alone is less desirable and inefficient

in 'terms of air-water contact.

(3) Artificial Lake: Artificial lakes are man-made bodies of water which offer

possible alternative to once-through cooling. The heating effluents can, be discharged

into the lake at one end and the water for cooling purpose may be withdrawn from the

other end. The heat is eventually dissipated through evaporation So these lakes, have

to be rejuvenated continuously.

Radioactive Pollution

NUCLEAR HAZARDS Radioactive (nuclear) pollution is a special form of physical

pollution related to all major life-supporting systems-air, water and soil. It is always

convenient to discuss radioactive pollution separately because its nature of contamination is

different from other types of pollution. Its effects are also of special kinds. Radioactivity is

the phenomenon of emission of energy from radioactive isotopes (i.e.unstable Isotopes), such

as Carbon-14, Uranium~235, Uranium-238, Uranium-239, Radium-226, etc. The emission of


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energy from radioactive substances in the environment is oftenly called as Radioactive

Pollution:

Sources: The sources of radioactivity are both natural and man-made. The natural sources

include: (I) Cosmic rays from outer space. The quantity depends on altitude and latitude, it is

more at higher latitudes and high altitudes. (ii) Emissions from radioactive materials from the

Earth's crust. People have been exposed to low levels of radiation from these Mtural sources

for several millenia. But it is the man-made sources which Ire posing a threat to mankind.

The man-made sources of radioactivity Ire nuclear wastes (i.e. waste material that contains

radioactive nuclei) produced during the: (I) mining and processing of radioactive ores; (ii)

use of radioactive material in nuclear power plants; (iii) use of radioactive isotopes in

medical, industrial and research applications; and (iv) use of radioactive materials in nuclear

weapons. The greatest exposure to human beings comes from the diagnostic UR of X-rays,

radioactive isotopes used as tracers and treatment of cancer and other ailments

The radioactive pollution can be controlled by number of ways. It includes the stoppage of

leakage from the radioactive materials including the nuclear reactors, industries and

laboratories. The disposal of radioactive material must be safe and secure. They must be

stored in the safe places and must be changed into harmless form. The wastes with a very low

radiation must be put into the sewage. The nuclear power plants must follow all the safe

instructions. The protective garments must be worn by the workers who work in the nuclear

plants. The natural radiation must be at the permissible limits and they must not cross it.

Radioactive pollution occurs when ‘Radioactive’ metals disintegrate releasing

dangerous beta rays which can cause cancer and other mutative diseases.


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These types of pollution can occur by either the dumping of radioactive waste from

nuclear power plants into water bodies, damage of nuclear reactors leading to

radioactive contamination that would last for many years and many more.

In the Second World War, when the U.S.A attacked Hiroshima and Nagasaki of

Japan, the atomic bomb left a radioactive footprint leading to highly mutative

diseases. So, most of the people who survived the atomic bombing died eventually

from cancers and mutations.

Sources of Radiations:

Sources of radiations:

I. Natural Sources of radiation

II. Man-made sources of radiation

(I) Natural Sources of Radiation:

Nuclear reactions have produced a large number of unstable nuclei or isotopes which

lose subatomic particles and emit high energy radiations to acquire a stable state. This

process continues and constitutes an important source of radiations for the biosphere.

In addition earth's surface is regularly irradiated by X-rays, cosmic rays and

ultraviolet rays from outer space and terrestrial radiations from radio nucleides.

Uranium -238, thorium -232, radon -222, potassium -40 and carbon -14 occur

naturally in rocks, soil and water.


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(II) Man-made Sources of Radiation:

Man-made sources of radiations are mining and refining of plutonium and thorium,

production and explosion of nuclear weapons, nuclear power plants fuels and

preparation of radioactive isotopes.

Medical and diagnostic uses of radioactivity are the most important source of

radiation to general public. There are numerous X-ray clinics and hospitals where

radioactive isotopes of cobalt and iodine etc. are frequently used for diagnostic or

curative purposes in the treatment of cancer and hyperthyroidism. Colour televisions,

computer screens, videogames are also sources of radiation to general public.

Nuclear Hazards:

Explosion of two atomic bombs in Nagasaki and Hiroshima killed innocent people,

animals and damaged plants. Explosions are uncontrolled chain reactions which give

rise to very large neutron flux condition which make other materials in the

surroundings radioactive. These materials include Strontium-90, Cesium- 137, Iodine-

131 and unused explosive and activation products.

These particles settle down to cause water and soil pollution. With rain drops falling

on the ground radioactivity is transferred to the soil. It is from such soil, the

radioactive substances enter the food chain, thus, affecting different forms of life. The

aquatic organisms absorb and accumulate the radioactive materials.


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NOISE POLLUTION:

Noise, an unwanted sound, is a phenomenon that has plagued us from the day we were born.

Sound is either music or noise-so goes an old saying. What is implied by this distinction is

that-whatever is pleasant to ear is music, while all that is unpleasant is noise. Such phrases as'

grating on the ears' or 'jarring on the nerves' express the discomfort we feel on hearing

unpleasant sounds. It is such unpleasant/unwanted impacts of sound that are collectively

described as noise pollution. It annoys and hurts people both psychologically and


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physiologically. Thus, noise may be defined as, "the undesirable sound that interferes

significantly with the comfort, health or welfare of persons, or with the full use or enjoyment

of property." It can be intermittent (non-uniform), continuous (uniform), or instantaneous

(impulsive). Sound is produced by the vibrations of an object or mechanism and transmitted

in the form of waves-alternating increase and decrease in pressures. It radiates outward

through a material medium of molecules, more or less like the ripples spreading out on water

surface when some heavy object (say stone) has been thrown into it. The speed of sound

varies according to the nature of the carrier media.

In water, sound travels about 5 times faster than in air. In iron and steel it is even faster, about

3 times faster than the speed in water. Unlike all other pollution causing components of

environment (such as waste water, contaminated air, and solid waste), sound/noise is not an

element, compound or substance which can accumulate and harm future generations. It is a

special kind of wave-action usually transmitted by air, in the form of pressure waves and

received by the hearing apparatus (ear) in the body of human beings and animals.

Unit of Measurement:

Two properties of sound are important, namely the pitch or frequency, and intensity or

pressure or energy. The pitch or frequency refers to the rate of vibration of the sound, and is

measured in Hertz (Hz) units. The frequency of sound is determined by the number of times

the vibrating waves undulate per second. The slower the cycle, the lower the pitch or

frequency. The pitch becomes higher as the cycles increase in number. Decibel (dB) is used

in environmental noise pollution as a measure of sound power level, sound intensity level,

and sound pressure level.

A decibel is a physical unit based on the weakest sound that can be detected by the human

ear. It is named after Alexander Graham Bell, the inventor of the telephone.


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Loudnesess:

The sound levels of power, intensity and pressure are the physical effects which the human

ear receives; it is not, however, what the person perceives. What is being perceived or heard

depends on how the human brain interprets or perceives the sound levels received by the ear.

Loudness is the brain's perception of the magnitude of the sound levels. The brain's

interpretation of loudness depends on the magnitude of vibration produced in the ear

mechanism.

The higher levels of sound produce more vibration in the ear mechanism, and vice-versa, and,

hence, accordingly the brain perceives the sound as loud and not loud, respectively. Thus,

what is actually heard is not the decibel (dB) level but the interpretation of it.

Measurement of Noise:

Noise is measured by means of a sound level meter The sound level meter, is positioned in at

desired location; with no obstruction from the sound source, and then reading is taken.

Whenever possible, the sound level meter should be mounted on a tripod and the operator

should be at least 0.5m away from the nearest edge of the level meter. The outdoor

measurements are made 1.2to 1.5m above the ground and at least 3.5 m away from the

reflecting surfaces such as buildings. Indoor sound measurements should be made at least

1.2to 1.S m above the floor, at least 1.0m from walls and 1.5 in from windows. Indoor

measurements are normally made with windows closed. Measurements that deviate from

these recommended distances should be specified accordingly.


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Effects of Noise:

Noise affects human body in a number of ways, ranging from psychological to physiological

effects. Some of the important effects are as under:

(i) Auditory effects. There is no doubt that exposure to intense levels can cause

temporary or permanent shifting of the threshold of hearing, in those persons who

are exposed to high noise levels over a long span, for example, factory workers.

(i) Continuous exposure to noise levels above 100 dB has adverse effect on the

hearing ability within a fairly short time. Besides progressive hearing loss, there

may be instantaneous damage or acoustic trauma. This is usually caused by a very

high intensity impulsive noise of about 150dB or more (e.g., from explosion)

bursting of a fire cracker very near to the ear.

(ii) Speech interference. A person may face the problem of trying to 'understand

another person talking to him in an environment with a high background noise

level. Background noise level can thus affect the efficiency of offices, schools and

other places where communication is of vital importance. External sounds can

also interfere with conversation and use of the telephone, as well as the enjoyment

of radio and TV. The maximum acceptable level of noise under such conditions is

55 dB. Background noise level of 70 dB is considered very noisy and serious

interference with verbal communication is inevitable.

(iii) Sleep interference. The arousal from sleep depends upon the intensity of noise,

degree of fluctuation, depth of sleep, accumulated sleep, age, effect of alcohol or

drugs, etc. Frequent sleep interference is a health hazard, since it deprives a person

of the restorative process for his organs to renew their supply of energy and

nutritive elements provided by a good night's sleep.


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(iv)General annoyance: General annoyance is felt at about 75 to 85dB. Blood

vessels get constricted, breathing rate is affected, and muscle tension' changes.

(v) Task interference (working efficiency): The effect of noise on the human

performance of tasks is a complicated subject that is under continued study. Many

people complain that noise makes them mentally ill and reduces their working

efficiency. Experiments indicate that irregular bursts of noise are more disruptive

than steady noises; and sound levels of 90dB.

(iv) Reduce noise by enclosing a noisey machine, providing elastic suspension

between the machine and its supporting structure, reducing speed of operation,

using vibration dampening materials, modification in the design of machine,

oiling and greasing of moving parts of the machine, etc. But for best results, these

efforts at controlling noise at source should occur in the early design stages. Such

a step can save many problems because later modifications may be .costly and

technically impractical. In the early stages, it makes a sense in choosing a quieter

machine. Path Source Receiver

(v) Introduction of sound barriers between the source and receiver (like walls,

landscapes, plant growth particularly shrubs along highways, railways, etc.), use

of reflectors which help in reflecting sound waves into the upper atmosphere and

thus reducing the impact of noise pollution, and use of absorptive materials such

as acoustic tiles, curtalns, boards, wood panelling, porous bricks, etc. buildings. .

In situations, where neither source modifications nor path modifications reduce

the noise to acceptable levels, direct protection of the receiver is necessary. In

industrial situations, this includes rotating staff members from one room to

another, issuing ear protection equipments (like ear muffs, ear plugs, and throw-


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away ear plug materials such as cotton), issuing personal noise dosimeters

maintaining regular audiograms to monitor worker's hearing capabilities, .

Light Pollution

Bright lighting in functions, big cities, etc. causes “Light Pollution”. Excessive light

on the retina causes extreme discomfort in the eyes, especially in dim conditions like

during night time.

Bright lights strain the eyes and also give headaches and migraines.

Different Types and Sources of Light Pollution:

1. Over-illumination: This is caused by misuse of lights. Lights that are left on, or even street

lamps that aren’t adjusted for daylight savings time, can cause millions of barrels of oil to be

wasted. It can have the immediate effect of raising utility costs in an area as well as

disrupting natural sleep patterns.

2. Glare: Glare is a two-fold problem in which lights are reflected off surrounding surfaces so

that the light scatters and causes vision problems. It doesn’t interfere with night vision, but

makes it difficult to identify and place objects.

5. Light Trespass: Not only is this a form of pollution but it is also a crime in many areas.

Light trespass refers to unwanted light entering someone’s property. It could be light from a

sign coming into a residential area or any similar circumstance.

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Causes of Light Pollution

Light pollution is unique as it is caused by man only. There is no comparable natural form of

the pollution like there is with carbon dioxide. The main causes of light pollution are:

Poor Planning – The placement of signage and street lights is planned by

engineers, if they do not take into account the effect placement has on

the surrounding environment they can create glare, light trespass and light clutter.

Irresponsible use – You may love Christmas lights but leaving them on all night is

a form of pollution, as is leaving a room with the lights still on or setting the

timers on streetlamps and not adjusting the timer for the season. Not actively

choosing to minimize energy waste is a huge source of light pollution.

Overpopulation – That is really a zoning issue. Too many businesses, or too many

residences, grouped in one area can cause light pollution of many kinds.

Effects of Light Pollution

While many people choose to dismiss light pollution as being the price of modern life, it has

serious effects on everything around it.

Animals – Lights can attract or repel animals and insects. Most animal life

functions on a diurnal or nocturnal system that is thrown out of sync by light

pollution. This can place entire species in danger, or attract unwanted species into

human areas.

People – The wrong kind of light, or too much light has been proven to have an

impact on your health and quality of life. Light pollution also increases danger to

people as it can interfere with important navigational systems for trains, planes

and even automobiles.

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Solutions for Light Pollution

There are two fundamental approaches to explain light pollution – planning and education.

Planning resources additional deliberation concerning how areas are zoned and where lights

are located. It also resources altering the types of lights used inside the home, symbols and

streetlamps to more efficient bulbs, and with a light output that is not so disruptive. Education

is also key. The more people understand the importance of turning off lights to conserve

energy and reduce light pollution the faster change will be seen.

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03 Other major types of Environmental Pollution

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