ENVIRONMENTAL SCIENCE ENGINEERING

UNIT-II

1. Give one example for sustainable development.i) water conservationii) rain water harvesting

2. What is Rio de Janeiro conference agreement?The Rio declaration outlines the rights and responsibilities of nations as

they pursue human development and well being, recognizing the development and environment and needs of present and future generations.

3. Define sustainable development It is defined as ‘the development to meet the needs of the present without compromising the ability of future generations to meet their own needs’. Sustainable Development must balance the needs of society, the economy and the environment.

4. Define sustainability.Sustainability can be defined as the ability of a society or ecosystem to

continue functioning into the indefinite future without being forced into decline through complete loss of its strength or overloading of key resources on which that system depends.

5. What are the characteristics of a sustainable development?i) All the material processes will be designed to be of cyclic nature.ii) There will not be any waste material or pollution of air, water, land andenvironment.iii) The output from one system will be used as inputs to other systems.

6. Mention the few types of pollution. The five types of pollution are

1. Air pollution2. Water pollution3. Land or soil pollution4. Radio active pollution5. Noise pollution

7. What are the impacts of man made pollution?

i) Industrial developmentii) Rapid growth of Automobilesiii) Uncontrolled population growthiv) Deforestation

8. Give examples on water borne diseases.

Water Borne Diseases Responsible Organism

Typhoid, paratyphoid, Diarrhoea, Cholera, Bacillary dysentery

Bacteria

Amoebiasis, Giardiasis Protozoa

ViralHepatitis (Jaundice), Poliomyelitis Virus

Round worm, hookworm, threadworm Helminths

9. What are the major issues of sustainable development?i) Deforestation and desertificationii) Urbanizationiii) Industrialization

10.Define air pollution.Air pollution may be defined as any atmospheric condition in which

certain substances are present in such concentrations that they can produce undesirable effects on man and his environment.

11.Define water pollution.It can be defined as “ the presence of some foreign substances or

impurities in water in such quantity as to constitute a health hazard by lowering the water quality and making it unfit for use.”

12.Mention a few natural sources of pollution.

i) Forest fires produce more smoke and trace gases into the atmosphere.ii) Explosive Volcanic eruptions can inject more SO2, smoke, particulate matter and trace gases.iii) Dust storms are the main cause for wind blow dust in the air.iv) Natural contaminants present in the air like bacteria, spores, cysts and pollens are more dangerous when inhaled.

13.Correlate Global warming with reference to CO2 concentration in air.Global warming is defined as the increase in temperature of the earth

which causes more changes in climate. CO2 plays the vital role to change in the intensity of the earth’s green house effect by about 55%.

14.What is the goal of environmental protection?The ultimate goal of environmental acts and policies are to minimize the

environmental impacts and to achieve a pollution free atmosphere or environment.

15.What are the various quality objectives of air? Clean air

No acid rain Non toxic environment Total freedom from radiation

16.Mention any two environmental impacts of developmental project in your discipline.

i)pollutionii)destroying the natural resources

17.Mention the environmental impact of high sodium content in soil.i) Reduction of soil fertilityii) Hazardous for human beings.

18.What are the causes for air pollution?i) Industriesii) Automobilesiii) forest firesiv) Radioactive materials

19.How will you rectify water pollution?i) Sewage treatmentii) Waste stabilization pond or oxidation pondiii) Recycling

20.What is acid rain?The presence of excess acid in the rainwater is called acid rain.acid rain is caused by air pollution. air pollutants causing acid rain are SO2 and nitrogen oxide

21.Define Green house effect.It may be defined as “the progressive warming up of the earth’s surface due to blanketing effect of man made CO2 in the atmosphere.

22.What are the gases responsible for green house effect?a. Watervapour(H2O)b. Carbon dioxide(CO2)c. Methane(CH4)d. Nitrous oxide(N2O)e. Ozone(O3)

23.How is ozone layer depleted? i)one CFC molecule can destroy thousands of molecules of ozone ii) halons are used in fire extinguishers. they do 10 times greater damage to the

ozone compared to the CFCs.

24.Name the toxic metals which cause water pollution?Mercury,copper,lead,zinc,cyanides,arsenic etc.

25.What are the toxic metals which cause air pollution? i) Lead particulates (from automobile exhausts) ii) Cadmium particulates (through cigarette smoking) iii) Nickel particulates (in tobacco smoke)

Part-B (12 Marks)

1. Explain the various physical properties of soil owing to the impacts on land

PHYSICAL CHARACTERISTICS:

The physical characteristic of soil includes permeability, porosity, density and temperature.

1. Soil density:

i. The soil density varies greatly depending upon the degree of weathering.ii. The average density of soil is 2.65gm/m

2. Porosity

i. In a given volume of soil, the spaces present between the soils particles is called as pore spaces. The percentage of soil volume occupied by pore spaces is called as porosity of the soil.

ii. It increases with increase in the percentage of organic matter in the soil.iii. The two types of pore spaces are:

a. Micro pore spaces andb. Macro pore spaces.

iv. Micro pore spaces are also called as Capillary pore spaces. They can hold more water.

v. The micro pore spaces restrict the free movement of water and air to a considerable extent.

vi. The macro pore spaces have little water holding capacity and they allow free movement of moisture and air in the soil under normal conditions.

3. Permeability:

i. The movement of water through the pore spaces is called as permeability of soil.

ii. It always depends upon the size of the pore.iii. Loose soils have higher value of permeability and the compact

soils have lesser permeability.4. Temperature:

i. Soil temperature is also important in affecting the distribution and growth of micro organisms, animals and plants which is affected by the following different factors:

a) Color.b) Texture.c) Water content.d) Climate ande) Vegetation covers over the soil.

ii.The soil temperature influences root growth, the ability of roots to absorb nutrients, and the movement of organisms.

iii.Sandy soils absorb more heat and radiate it out quickly than clay or loam soils, while soils absorb lesser heat than black so

2. Briefly explain how natural calamities disturb the environment. Natural calamities:

i. floodsii. droughtiii. earthquakeiv. cyclone

i. Floods:When the water from heavy rainfall,melting ice or snow or a combination of

these exceeds the carrying capacity of the receiving river system,then it will lead to flood.

Causes of flood:i.natural causes:

a. the natural factors which causes river floods are prolonged high intensity monsoonal rainfall.b. In the snow fed rivers of north india,excessive snow -melt Could swell up the streams causing them to flood.c. Blocking of free flow of the rivers because of enormous debris provided by land slides creates over flow of river water.

ii. Anthropogenic causes:

Large scale deforestation in the upper catchments of major rivers. it leads to excessive flow of water to the plants causing floods and inundation.

Accumulation of wastes, refuse and garbage, filling of urban drains, gradual encroachment of human settlements near the channels, building construction of roads are the significant factors causing river floods.

Effects of floods: Deforestation. Damage to vegetation. River change their course during floods.Flood control measures:

a) flood plain zoningb) flood-proofing measuresc) flood risk maps

ii. Drought:

It is defined as an extended period a season, a year, several years of deficient rainfall relative to the statistical multiyear average for the region.

Causes:Lack of rain fall

Inadequate water supply to plants, animals and human beings.There is a serious scarcity of water to drink, use in farms, or provide for urban and industrial use.Impacts of drought:

i. Effect on agriculture,economy and health Crop losses Loss of income Causes of disaster

ii. Effect on forestry and water resources

Wild fires Tree and plant diseases Less productivity of forest land Land degradation

Control measuresConstruction of tanks,ponds ,dams,reservoirs and wells to provide irrigation facilities

iii. Earthquake: It is a sudden shaking of the earth. It is a sudden vibration caused on the earths surface.

Causes: Movement of the earth’s tectonic plates. Sometimes due to friction,these plates are not able to slip in their natural

manner.Control measuresResistant buildings in the earth quake prone areas.

iv. Cyclones: Cyclones are intense storms that develop over warm tropical seas.

The main dangers from cyclones are very strong winds,torrential rains and high strom tides.

Mitigation measures: Installation of early warning systems Developing shelter belts Developing community cyclone shelters construction of permanent houses.

3. Explain natural and man made impacts on environment

NATURAL AND MAN MADE IMPACTS ON ENVIRONMENT

Man uses the natural resources to make comfortable life to him and his generations. The water we drink, the air we breathe and the places where we live are getting polluted every where. In addition to his activities the nature has also made some destruction in the nature environment. The two main sources of pollution are:

(1) Natural sources of pollution

(2) Man made (or) Anthropogenic sources of pollution

Types of Environmental pollution:

The five types of pollution are

1. Air pollution2. Water pollution3. Land or soil pollution4. Radio active pollution5. Noise pollution

Impacts of Natural sources of pollution:

Some of the natural sources of pollution are:

i) Forest fires produce more smoke and trace gases into the atmosphere.ii) Explosive Volcanic eruptions can inject more SO2, smoke, particulate matter

and trace gases.iii) Dust storms are the main cause for wind blow dust in the air.iv) Natural contaminants present in the air like bacteria, spores, cysts and pollens

are more dangerous when inhaled.v) Carbon monoxide will be produced from the breakdown of methane gas in the

marsh lands.vi) Spraying of salts from oceans.vii) Electrical storms produce oxides of nitrogen in the atmosphere which leads to

ozone depletion.Impacts of Man made sources of pollution:

The pollution of water, air and land are created and developed every day. They are made more complicated due to rapid growth of industries and population. Some of the anthropogenic sources of pollution are

1. Industrial development2. Rapid growth of Automobiles3. Uncontrolled population growth4. Deforestation5. Over exploitation of natural resources6. Use of fertilizers, pesticides etc., in agricultural activities7. Mining activities8. Nuclear explosions

Impacts on Atmosphere:

The dust and carbon particle make our cities dirty, spoil our material goods. Coal smog reduces visibility and is a major cause of traffic accidents. Inhalation of asbestos fibers causes a serious occupational and health problem

(asbestosis), which leads to cancer and even death. The exhaust gas of automobiles contains more amount of unburnt fuel with

more carbon monoxide. Inhalation of carbon monoxide in human beings leads to carboxy hemoglobin, which carries the oxygen carrying capacity of blood.

The emissions from various types of industries and automobiles contain Sulphur-dioxide and nitrogen oxides. These gases combine with rain, smog and fog form acid rain.

Release of CFC into the atmosphere causes depletion of ozone layer. That makes more health problems such as skin cancer and eye disorders in human beings.

The release of air pollutants into the atmosphere increase the atmospheric temperature, known as global warming. The major effects are melting of ice caps, rising in sea levels and variation in seasons.

Impacts on Land:

Disposal of industrial effluents and domestic wastes on land causes loss of its fertility.

Removal of the top soil of land causes low fertility for crop production. Deforestation, the process of changing land use from forestry to a non forest use,

is threatening the existence of many species.Impacts on Water:

Change in colour will affect the usage of water and growth of plants and organism of water.

The dissolved oxygen content of the water body is reduced by organic substances. The water becomes unfit for drinking and other purposes because of inorganic

substances. Oil and other lubricants will affect the self purification of the water body. Enrichment of nutrients (Eutrophication) from surrounding watershed affects the

penetration of light through the water, causing damage to the characteristics of that water and aquatic life.

Sewage disposed into water bodies’ results in many water borne infectious diseases to the human beings. The different types of organisms and water borne diseases are

Water Borne Diseases Responsible Organism

Typhoid, paratyphoid, Diarrhoea, Cholera, Bacillary dysentery

Bacteria

Amoebiasis, Giardiasis Protozoa

ViralHepatitis (Jaundice), Poliomyelitis Virus

Round worm, hookworm, threadworm Helminths

Disposal of coolant water used in industries increase the temperature of the surface water. This increase in temperature affects the aquatic ecosystem.

More amounts of nitrates in water due to the application of artificial fertilizer in agricultural lands can cause methemoglobinemia known as blue baby disease.

4. Briefly explain the sustainable development.CONCEPT OF SUSTAINABLE DEVELOPMENT

In the year 1992, the United Nations Conference on Environment and Development (UNCED) held at Rio de Janeiro, recognized the pressing environment and development problems of the world. It produced a global program of action for sustainable development into the 21st century by adapting Agenda 21. According to the Agenda 21, the countries should adopt national strategies for sustainable development, which should provide a balance in the needs of plans and policies of society, the economy, and the environment of the country.

The first principle of Rio declaration is the sustainable development. The Rio declaration states that, ‘human beings are at the centre of concern for sustainable development. They are entitled to a healthy and productive life in harmony with the nature. Every generation should leave air, water and soil resources without any pollution as pure as it came to the Earth”.

Accordingly Sustainable Development is defined as ‘the development to meet the needs of the present without compromising the ability of future generations to meet their own needs’. Sustainable Development must balance the needs of society, the economy and the environment.

The natural resources must be used in such away that, its utility will not limit their availability of water to the future generations. Sustainable development of water resources require the use of renewable water resources that are not diminished over the long term by that use.

The developed and most easily accessible renewable water resources are streams, lakes, rivers and aquifers that recharge quickly. The process of developing less accessible fresh

water resources will be costly and is time consuming. The environmental and human costs of these projects can also be very high.

The three important components of sustainable development are:

1) Economic development (like industrial development, creating job opportunities, utilization of natural resources for developing the quality of life).

2) Community development (providing food, shelter, cloth, education and other essentials for the human beings).

3) Environmental protection (providing clean air, water and environment for the present and future generations and utilization of resources in a sustainable manner).The frame work for the integration of developmental strategies with environmental protection is provided by the concept of sustainable development which includes the following.

1) Use of excessive resources is to be reduced with increasing resource conservation.2) Waste minimization should be adopted with more recycling and reusing of

materials.3) Enhancing scientific, management of renewable resources.

Sustainability:

Sustainability can be defined as the ability of a society or ecosystem to continue functioning into the indefinite future without being forced into decline through complete loss of its strength or overloading of key resources on which that system depends.

Stability has two aspects which are almost opposite in nature.

(i) Resistance stability.(ii) Resilience stability.

Resistance stability is the ability of a system to remain stable in the face of stresses and Resilience stability is the ability of the system to recover from the disturbance occurred due to the activities happened.

Characteristics of a sustainable development:

If a sustainable society is developed in the future, it is likely to have the following characteristics.

(i) All the material processes will be designed to be of cyclic nature.(ii) There will not be any waste material or pollution of air, water, land and

environment.(iii) The output from one system will be used as inputs to other systems.(iv) Only renewable energy will be used in the society, either or in the forms of

hydro power, wind power, solar power and biomass.(v) The human population will be either stable in size or gradually declining.

Major issues of Sustainable Development:

Some of the vital issues of environmental problems facing the developing countries are explained as follows:

(a) Land: Deforestation and desertification are the major terrestrial problems that are drastically caused by the factors such as overgrazing, massive land clearing and reduction in agricultural productivity. These factors in turn promote serious environmental issues such as increased flooding, sedimentation and silting up of dams and reservoirs. The problem is further complicated by the burning of forest woods for fuel by the rural population who are not affordable for other fuels thereby contributing for the rapid depletion of wild life reserves and ecological imbalance. The gradual extinction of plant and animal species that occurs at an accelerated pace is yet another serious problem which might cause multidimensional and irreparable loss to the future human society and also biodiversity.

(b) Pollution: Environmental pollution that is mostly caused by urbanization and industrialization provides growing concern n all developing countries. The alarming status of air and water pollution in certain Indian metropolitan cities like Calcutta, Mumbai and Delhi are similar to that of in other developing countries. Improper waste disposal and unhygienic water resources along with poor sanitary conditions further version and aggravate the environmental issues in several developing countries.

Excess use of fertilizers and pesticides are the other crucial agricultural problems that heavily contribute to environmental pollution. Acid rain, ozone depletion and global warming have become the major global issues that would result in catastrophic impact on environmental conditions.

Suggested measures for sustainable development:

1) It becomes meaningful to understand the uncertainties in totality, before depending on the popular predictions made by the section of our scientists and bureaucrats about the drastic consequences global warming. If it is not able to conduct specific scientific studies for want to proper funding sources, it is suggested that our country should involve and associate with the modeling research programmes conducted by World Meteorological Organization (WMO) and Global Environmental Monitoring system (GEMS).

2) Implementation of energy conservation procedures by reducing distribution losses of electricity, increasing the operative efficiencies of agricultural pump sets and switching over to sodium lamps for lighting.

3) Proper finding of alternate sources of energy such as nuclear, solar, wind energies and natural gas.

4) Typical modifications in the agricultural techniques by minimizing the use of synthetic fertilizers and switching over to organic farming.

5) Conservation of existing forests and creation of new forests by aforestation.

5.Describe in detail about effects of water pollution on environment

Water pollution can be defined as “the presence of some foreign substances or impurities in water in such quantity as to constitute a health hazard by lowering the water quality and making it unfit for use”.

MAJOR SOURCE OF WATER POLLUTION:

Point sources and non-point sources (diffused sources) are the two types of sources.

a) Point sources:The sources that pollute water bodies at a single location such as sewage channels are called point sources.

b) Diffused sources:The sources that pollute water at unknown locations or scattered places are called diffused sources.

e.g. pesticides and fertilizers, mining and construction activities.

WATER POLLUTANTS:

a) suspended matter:Domestic and industrial sewage are the main sources of suspended matter.

e.g. detergents, soaps, lubricating grease products.

b) Inorganic and organic compounds:Example:acids, alkalis, metals and synthetic organic compounds, Industrial effluents from paper mills, tanneries and food-processing units.

c) Pathogenic organisms:Pathogenic organisms such as bacteria, viruses, protozoa forms and helminthic worms are the important pathogenic pollutants that are usually found in the polluted domestic sewage, agricultural runoff, industrial effluents and waste water from animal- slaughtering houses, thus causing environmental stress.

d) Thermal discharges:The heated water from several power plants and thermal

Industries are pumped into the nearby water bodies and also

wet lands.

Causes of water pollution

i)domestic sewage

ii)industrial effluents

iii)thermal pollution

iv)oil pollution

v)radio active pollution

Effects of water pollution

i)water borne diseases

ii)effects of organic pollutants

iii)effect of sediments

iv)effects of organic chemicals

v)effect o0f pesticides

vi)effect of radio active pollutants

Control measures for water pollution:

a)sewage treatment

b)waste stabilization pond or oxidation pond

c)recycling.

6. Write in detail about the influence of air pollution.Air pollution:It may be defined as any atmospheric condition in which certain substances are present in such concentrations they can produce undesirable effects on man and his environment.

AIR POLLUTION DUE TO INDUSTRIES AND VEHICLES:

Industrial and auto mobile emission have been identified as primary contributors of major portion of air pollution.

Industrialization which represents an inevitable constituent in civilized modernization.

Vehicles using fossil fuels cause air pollution through the emission of toxic pollutants into the atmosphere.

The elegant beauty of TajMahal which is the glorious and fantastic Monument of international repute is getting degraded and deteriorated by the loss of its fascinating beauty due to the constant emissions of refinery industries situated at Mathura.

Analysis of the chemical composition of emissions of both industries and automobile vehicles have revealed the following toxic pollutants.

SUSPENDED PARTICULATE MATTER: Particulate matter primarily consists of suspended or dispersed matter solid or

liquid particles than 10 µm called aerosols. Sources – Wind-blown soil dust, evaporated sea-spay droplets and volcanic

eruptions, combustion of fossil fuels.

Pollutants Sources Health effects

Carbon monoxide

Incomplete fuel combustion(two stroke engines and 3 wheelers)

Aggravates heart disorders, affects central nervous system and O2

carrying capacity

Nitrogen oxides Fuel combustion of motor vehicles and furnaces

Irritation and inflammation of respiratory tract

Oxidants and ozone Emission from motor vehicles

Photochemical reaction s of nitrogen oxides

LeadEmissions from motor vehicles

Extremely toxic, affects nervous system and blood, causes hyper tension, impairs mental development in children

Volatile hydro carbons

Disposal of solid wastes, partial combustion of carbonaceous fuels

Cough, eye irritation and drowsiness.

Sulphur dioxide

Burning of sulphur containing fuel like coal in power plants and oil by vehicles

Irritation of eyes, nose and throat sneezing, coughing and nausea.

These are found to be carcinogenic and stimulate serious respiratory disorders such as asthma and pneumonia.

Causes of air pollution:i)industriesii)automobilesiii)forest firesiv)oceansv)agriculture

vi)marshesvii)radioactive materialsviii)freonsEffects of air pollution:i) effects of air pollution on human healthii) effects on plantsiii) effects of air pollution on materialsiv) effects of air pollution on the stratosphere

7. In a detailed manner discuss the land pollution and its effects.Land pollution:It may be defined as “the contamination of the soil resulting in either reduction of its frtility or entry of contaminants in plants which subsequently enter the food chain and impart toxic or detrimental effect on the consumers.Causes of land pollution:i)soil erosionii)industrial wasteiii)agricultural wasteiv)urban wastev)biological pathogensvi)radioactive wasteeffects of soil pollution:i)effects of industrial pollutantsii)effects of urban waste productsiii)effects of radioactive pollutantscontrol of soil pollution:

i) solid wastes may be treated by pyrolysis methodpyrolysis is the nbreakdown of solid wastes by heat in the absence of oxygenii)sanitary land fills:

dumping of untreated wastes in the layers of earth and then covering it with soil should be adopted.

Recycling and reuse of wastes,like paper,plastic,glass,metals,etc should be encouraged

The garbage and night soil can be converted into compost manure Natural soil micro-organisms should be preferred over pesticides and

incsecticides Bio degradable organic waste should be used for generation of biogasSoil conservation:Conserving healthy soil and restoring degraded soils will require rethinking on modern agricultural and other land use practices

8.Explain the factors which develops the environment.

The two major criteria i.e. a project should maximize economic returns, and it should to technically feasible.

There are two different aspects of impacts of development on environment.

i.e. Local and global impacts.

Every developmental activity be it the construction of hydel projects, thermal power plants, urbanization, communication projects, industry, or agriculture has some impacts on the environment.

INDUSTRY:

The air, water, and hazardous waste pollution by industries has now become the biggest environmental problem.

The emission and effluents of some of the industries are extremely polluting and dangerous such as industries, manufacturing pesticides, fertilizers, pulp and paper, distilleries, dye manufacture etc.

These pollutants could have several synergistic-long term effects.THERMAL PLANTS:

The thermal plants affect the occupational safety and health due to heat, noise, dust and chemical pollutants.

The immense quantities of fly ash produced by these thermal plants also cause degradation of soil and conversion of useful agricultural land as dumping ground of this fly ash.

The thermal plants could affect the quality of life, habitat of endangered species of wild life or plants, sites/monuments of historical and cultural importance up to 25 km radius.

The cooling waters which have a temperature higher than that of natural water bodies, when disposed off in these bodies, results in loss of dissolved oxygen and thus, adversely affects aquatic life.

HYDEL PROJECTS:

Earlier hydel projects were considered to be least polluting and with minimum environmental effects.

Some of the effects on environment are:

Heath effects:

Hydel projects result in formation of large reservoirs.

The large water bodies are known to result in introduction of water borne diseases in an area such as malaria and schistosomiasis epidemics.

Plant genetic resources:

(i) The recent food plant like wheat, rice, maize, pulses, oilseeds, fruits and vegetables have been developed from their wild and weedy relatives.

(ii) The formation of reservoirs upstream dams results in inundation in destruction of biotic resources of these areas for short term gain.

Aquatic resources:

Most of the dams, generally, do not have an arrangement for fish ladders or mechanisms or lift fish to reach their breeding spots.

The dams have therefore, adversely affected the fish production, a rich protein source.

Water logging and salinity problems in irrigated soils: About 10 million hectare irrigated area under agriculture is affected by

water-logging and salinity. Most of this is due to inadequate attention to drainage works in irrigation

projects and indiscriminate use of water for irrigation. Deforestation and soil conservation: Hydel projects require extensive road building activity, new settlements and

industries resulting in destruction of forest areas and stable slopes of hills resulting in frequent land slides, these further results in increased sedimentation, flash floods and loss of land fertility.

URBANIZATION

The shifting or rural population to the cities has severely overstrained infrastructure in the existing urban areas.

The local authority and the government as a result, are finding it difficult to provide adequate roads, water supply, sewage treatment plants, schools and hospitals.

The non point pollution from cities i.e. runoff washing away and solid waste from roads into nearby surface waters is yet to attract attention of the regulatory agencies.

COMMUNICATION PROJECTS:

The increasing road infrastructure in the country is encroaching more and more of agricultural and forest land.

It is also affecting the aesthetics, forest density, crops and is causing major health problems due to air pollution specifically in built up areas.

The in adequate drainage systems under the roads has also contributed to flooding and degradation of soils in a big way

9. Discuss the science of environment with attention to your branch of engineering.

ROLE OF ENGINEERS IN DEVELOPMENTAL PROJECTS:

It is the moral obligation and responsibility of engineers who are associated with the developmental projects to be aware of the consequences and impacts of the proposed projects on the environmental implications.

They have to strictly adhere to the rules and regulations that are enforced in environmental policies for the complete protection and maintenance of ecological balance in the sites where the proposed projects are to be constructed.

Ethical implications, that provide highest value for the sustained maintenance of biodiversity and ecological balance which in turn benefits the human welfare.

Exposure of knowledge on the biological characteristics of an environment would provide better insight and guidance to the engineers for handling the projects in an eco-friendly manner.

10. Discuss briefly about the environmental impacts on marine habitat.Marine

Marine pollution:

It is defined as the discharge of waste substances into the sea resulting in harm to living resources,hazards to human health,hindrance to fishery and impairment of quality for use of seawater.

Causes of marine pollution:

I) Oils

II) sewage

III) chemicals

IV) radioactive wastes

V) thermal pollutants

VI) metallic pollutants

Effects of marine pollution:

i) Physical effects of oil in water

reduction in dissolved oxygen

reduction in light penetration

ii) Effects of oil pollution on marine ecosystem

smothering coats of oils kill lichens and algae along the sea shores

extensive spreading of oil affects the floating plantation and marine life severely.

Waste from oil refineries and discharged petroleum from ships causes heavy damage to fishery.

Oil spilling causes lethal toxicity to aquatic flora

Direct oil coatings render the fish unable to respire and clog their gill slits.

Aromatic hydrocarbons in oil are carcinogenic and adversely affect plant metabolism.

The thin film of oil on the surface of water is called oil slick. oil slicks damage marine life .the oil slick damages the mangrove plants.

Coral reefs, the gardens of the sea, are damaged by oil slick.

Sea cows, the aquatic mammals, die off due to oil slick.

The sea birds are much affected by oil pollution and die.

Fish and shellfish production facilities are affected by oil slicks. the most important commercial damage comes from tainting, which imparts an unpleasant flavor to fish and seafood.

Birds are specially vulnerable to damage from oilspill.the spilled oil breaks down their natural coatings of oils and waxes which shield the birds from marine water. Ultimately they lose their insulation, start shivering and may freeze to death in winter.