BT Brinjal

• In 2006, Maharashtra Hybird Seeds Company submitted biosafety and efficacy data to the GEAC and applied for permission to conduct large-scale trials
• At the same time SC imposed a ban on the on-going field trials
• An expert committee was constituted by GEAC to look into the concerns raised by several civil society actors
• SC later lifted the ban on field trials
• After a series of reviews the environment ministry declared a moratorium on Bt Brinjal in Feb 2010

Risk assessment

• Civil society has demanded that the science of risk assessment be made rigourous, independent and peer-reviewed

 

Cold desert of India include areas of ladak, leh and kargil of kashmir and spiti valley of Himachal  Pradesh and some parts of northern Uttaranchal and Sikkim. Lies in rain shadow of Himalaya Oak, pine, deodar, birch and rhododendron are the important trees and bushes found there. Major  animal include yaks, dwarf cows, and goats.

Severe arid conditions – Dry Atmosphere

Mean annual rainfall less than 400mm

Soil type – sandy to sandy loam , Soil pH – neutral to slight alkaline.

Soil nutrient – Poor organic matter content ,low water retention capacity

Bio-diversity

Cold desert is the home of highly adaptive, rare endangered fauna, such as

Asiatic Ibex, Tibetan Argali, Ladakh Uriyal, Bharal, Tibetan Antelope (chiru),

Tibetan Gazelle, Wild Yak, Snow Leopard, Brown Bear, Tibetan Wolf, Wild

Dog and Tibetan Wild Ass (‘Kiang’ a close relative of the Indian wild ass) ,

Woolly hare, Black Necked  Crane, etc.

 

 

 

Ecology is  defined “as a scientific study of the relationship of the living organisms with each other and with their environment.”

The classical texts of the Vedic period such as the Vedas, the Samhitas, the Brahmanas and the Aranyakas-Upanishads contain many references to ecological concepts .The Indian treatise on medicine, the Caraka- Samhita and the surgical text Susruta-Samhita. contain classification of animals on the basis of habit and habitat, land in terms of nature of soil, climate and vegetation; and description of plants typical to various localities.

Caraka- Samhita contains information where air, land, water and seasons were indispensable  for life and that polluted air and water were injurious for health.

The environment is defined as ‘the sum total of living, non-living components;  influences and events, surrounding an organism.

Components of Environment

1. Abiotic – Energy, Radiation, TEMP, Water, etc.
2. Biotic- plants, animals, man, DECOMPOSER ETC.

Diesel engine exhaust fumes can cause cancer, humans” and it belong to the same potentially deadly category as asbestos, arsenic and ‘mustard gases.

Six main levels of organisation of ecology are:

1. Individual- Organism is an individual living being that has the ability to act or function independently.
2. Population-Population is a group of organisms usually of the same species,

occupying a defined area during a specific time,

3. Community- Communities in most instances are named after the dominant plant form

(species). A community is not fixed or rigid; communities may be large or small.

Types of Community-

On the basis of size and degree of relative independence communities may be divided into two types-

(a)  Major Community

These are large-sized, well organized and relatively independent. They depend

only on the sun’s energy from outside and are independent of the inputs and

outputs from adjacent communities.

E.g: tropical ever green forest in the North-East

 

(b) Minor Communities

These are dependent on neighbouring communities and are often called societies.

They are secondary aggregations within a major community and are not therefore completely independent units as far as energy and nutrient dynamics are concerned.

e.g: A mat of lichen on a cow dung pad.

The environmental factors determine the characteristic of the community as well as the pattern of organisation of the members in the community

The characteristic pattern of the community is  termed as structure which is reflected in the roles played by various population, their range, the  type of area they inhabit, the diversity of species in the community and the spectrum of interactions between them

Eco-System-An ecosystem is defined as a structural and functional unit of biosphere consisting of community of living beings and the physical environment, both interacting and exchanging materials between them. It includes plants, trees, animals, fish, birds, micro-organisms, water, soil, and  people.

When an ecosystem is healthy (i.e. sustainable) it means that all the elements live in balance and are  capable of reproducing themselves

 

Components of Ecosystem

The components of the ecosystem is categorised into abiotic of non-living and biotic of living components. Both the components of ecosystem and environment are same.

 

1. Abiotic Components

the inorganic and non-living parts of the world.  consists of soil, water, air, and light energy etc.  involves a ,large number of chemicals like oxygen, nitrogen-, etc. and physical processes including volcanoes, earthquakes, floods, forest fires, climates, and weather conditions.

Abiotic factors are the most important determinants of where and how well an organism exists in its environment. Although these factors interact with each other, one single factor can-limit the range of an organism.

 

1. a) Energy

Energy from the sun is essential for maintenance of life. Energy determines the distribution of organisms in  the environment.

1. b) Rainfall
2. c) Temperature :-Temperature is a critical factor of the environment which greatly influences survival of organisms. Organisms can tolerate only a certain range of temperature and humidity.
3. d) Atmosphere :It is made up of 21% oxygen, 78% nitrogen , 0.038% carbon dioxide and other inert gases (0.93% Argon, Neon etc).
4. e) Substratum :Land is covered by soil and a wide variety of microbes, protozoa, fungi and small animals (invertebrates) thrive in it
5. f) Materials:

(i) Organic compound

Such as proteins, carbohydrates,  lipids,  humic  substances are formed from inorganic compound on decomposition.

(ii) Inorganic compound

Such as carbon,   carbon dioxide, water, sulphur, nitrates, phosphates, and ions of various metals are essential for organisms to survive.

1. g) Latitude and altitude

Latitude has a strong influence on an area’s temperature, resulting in change of climates such as polar, tropical, and temperate. These climates determine different natural biomes. From sea level to highest peaks, wild life is influenced by altitude. As the altitude increases, the air becomes colder and drier, affecting wild life accordingly.( wild life decrease as altitude increase)

 

2. Biotic Components :Biotic components include living organisms comprising plants, animals and microbes and are classified according to their functional attributes into producers and consumers.

Primary producers – Autotrophs (self-nourishing) Primary producers are basically green plants (and certain bacteria and algae). They synthesise carbohydrate from simple inorganic raw materials like carbon dioxide and water in the presence of sunlight by the process of photosynthesis for themselves, and supply indirectly to other non- producers.

In terrestrial ecosystem, producers are basically herbaceous and woody plants, while in aquatic ecosystem producers are various species of microscopic algae.

 

1. b) Consumers — Heterotrophs or phagotrophs (other nourishing)

 

Consumers are incapable of producing their own food (photosynthesis).

They depend on organic food derived from plants, animals or both.

Consumers can be divided into two broad  groups

 

(i) Macro consumers- They feed on plants or animals or both and are categorised on the basis of their food sources.

Herbivores are primary consumers which feed mainly on plants e.g. cow, rabbit.

Secondary consumers feed on primary consumers e.g. wolves.

Carnivores which feed on secondary consumers are called tertiary consumers e.g. lions which can eat wolves.

Omnivores are organisms which consume both plants and animals e.g. man.

 

(ii) Micro consumers – Saprotrophs (decomposers or osmotrophs)

 

They are bacteria and fungi which obtain energy and nutrients by decomposing dead organic substances (detritus) of plant and animal origin.

The products of decomposition such as inorganic nutrients which are released in the ecosystem are reused by producers and thus recycled.

Earthworm and certain soil organisms (such as nematodes, and arthropods) are detritus feeders and help in the decomposition of organic matter and are called detrivores.

Classification of Eco-system

 

1. Natural Ecosystem-

Terrestrial- Forests, Grasslands, Deserts

Aquatic- Fresh Waters, Saline Waters, Marine Waters

Ecotone :- a zone of junction between two or more diverse ecosystems. For e.g. the mangrove forests represent an ecotone between marine and terrestrial ecosystem.

Characteristics of Ecotone

It may be very narrow or quite wide. It has the conditions intermediate to the adjacent ecosystems. Hence it is a zone of tension.

It is linear as it shows progressive increase in species composition of one in coming community and a simultaneous decrease in species of the other out going adjoining community.

A well developed ecotones contain some organisms which are entirely different from that of the adjoining communities.

Sometimes the number of species and the population density of some of the species is much greater in this zone than either community. This is called edge effect For example the density of birds is greater in the mixed habitat of the ecotone between the forest and the desert.

 

Niche

a  description  of  all  the  biological,  physical  and  chemical  factors  that  a  species needs to survive, stay healthy and reproduce. No two species have exact identical niches. Niche plays an important role in conservation of organisms.

Types of Niche

1. Habitat niche – where it lives
2. Food niche – what is eats or decomposes & what species it competes with
3. Reproductive niche -how and when it reproduces.
4. Physical & chemical niche – temperature, land shape, land slope, humidity & other requirement.

Biome

The terrestrial part of the biosphere is divisible into enormous regions called biomes, which are characterized, by climate, vegetation, animal life and general soil type.

No two biomes are alike.

The most important climatic factors are temperature and precipitation.

1. Tundra- Northern most region  adjoining the ice bound  poles. Devoid of trees except stunted shrubs in the southern part of tundra biome, ground flora includes lichen, mosses and sedges.

The typical animals are reindeer, arctic fox polar bear, snowy owl, lemming, arctic hare,  ptarmigan. Reptiles and amphibians are almost absent

 

2. Taiga- Northern Europe, Asia and North America. Moderate temperature than tundra. Also known as boreal forest.

The dominating vegetation is coniferous evergreen mostly spruce, with some pine and firs. The fauna consists of small seed eating birds, hawks, fur bearing carnivores, little mink, elks, puma, Siberian tiger, wolverine, wolves etc.

 

3. Temperate Deciduous Forest- Extends over Central and Southern Europe, Eastern North America, Western China, Japan, New Zealand etc.

Moderate average temperature and abundant  rainfall. These are generally the  most  productive agricultural areas of the earth The flora includes trees like beech, oak, maple and cherry. Most animals are the familiar vertebrates and invertebrates.

4. Tropical rain forest- Tropical areas  in  the equatorial regions, which is  a bound  with  life.  Temperature and rainfall high.

Tropical rainforest covers about 7% of the earth’s surface& 40% of the world’s plant and animal species.

Multiple storey of broad-leafed evergreen tree species are in abundance.

Most animals and epiphytic plants(An epiphyte is a plant that grows harmlessly upon another plant)  are concentrated in the canopy or tree top zones

5. Savannah- Tropical region: Savannah is most extensive in Africa

Grasses with scattered trees and fire resisting thorny shrubs.

The fauna include a great diversity of grazers and browsers such as antelopes, buffaloes, zebras, elephants and rhinoceros;  the carnivores include lion, cheetah, hyena; and mongoose, and many rodents

 

6. Grassland- North America, Ukraine, etc . Dominated by grasses. Temperate conditions with rather low rainfall. Grasses dominate the vegetation. The fauna include large herbivores like bison, antelope, cattle, rodents, prairie dog, wolves, and a rich and diverse array of ground nesting bird

 

7. Desert- Continental interiors with very low and sporadic rainfall with low humidity. The days are very hot but nights are cold. The flora is drought resistance vegetation such as cactus, euphorbias, sagebrush. Fauna : Reptiles, Mammals and birds.

Aquatic Zones

Aquatic systems are not called biomes,

The major differences between the various aquatic zones are due to salinity, levels  of dissolved nutrients; water temperature, depth of sunlight penetration.

 

1. Fresh Water Ecosystem-Fresh water ecosystem are classified as lotic

(moving water) or lentic (still or stagnant water).

 

2. Marine Ecosystem-
3. Estuaries-Coastal bays, river mouths and tidal marshes  form  the

estuaries.  In estuaries, fresh water from rivers meet ocean water and the two are mixed by action of tides.

Estuaries are highly productive as compared to the adjacent river or sea

 

Biosphere

a part of the earth where life can exist.

represents a highly integrated and interacting zone comprising of atmosphere (air), hydrosphere (water) and lithosphere (land) Life in the biosphere is abundant between 200 metres (660 feet) below the surface of the ocean and about 6,000 metres (20,000 feet) above sea level. absent at extremes of the North and South poles. Living organisms are not uniformly distributed  throughout the biosphere

 

FUNCTIONS OF AN ECOSYSTEM

ENERGY FLOW- Energy is the basic force responsible for all metabolic activities. The flow of energy from producer to top consumers is called energy flow  which is unidirectional.

Energy flows through the trophic levels: from producers to subsequent trophic levels. There is a loss of some energy in the form of unusable heat at each trophic level.

The trophic level interaction involves three concepts namely :-

1. Food Chain
2. Food Web
3. Ecological Pyramids
4. FOOD CHAIN- A food chain starts with producers and ends with top carnivores. The sequence of eaten and being eaten, produces transfer of food energy and it is known as food chain.

Grazing food chain-The consumers which start the food chain, utilising the plant or plant part as their food, constitute the grazing food chain.

This food chain begins from green plants at the base and the primary consumer is herbivore

For example, In terestrial ecosystem, grass is eaten up by caterpillar, which is eaten by lizard and lizard is eaten by snake.

In Aquatic ecosystem phytoplanktons (primary producers) is eaten by zoo planktons which is eaten by fishes and fishes are eaten by pelicans

Detritus food chain- The food chain starts from dead organic matter of decaying animals and plant bodies to the micro-organisms and then to detritus feeding organism called detrivores or decomposer and to other predators.

 

Litter —■Earthworms —■Chicken—■Hawk

Detritus food chain

The distinction between these two food chains is the source of energy for the first level consumers.

2. FOOD WEB

“A food web illustrates, all possible transfers of energy and nutrients among the organisms in an ecosystem, whereas a food chain traces only one pathway of the food”.

3. ECOLOGICAL PYRAMIDS

The steps of trophic levels expressed in a diagrammatic way are referred as

ecological pyramids.

 

The food producer forms the base of the pyramid and the top carnivore forms the tip. Other consumer trophic levels are in between.

The pyramid consists of a number of horizontal bars depicting specific trophic levels which are arranged sequentially from primary producer level through herbivore, carnivore onwards.  The length of each bar represents the total number of individuals at each trophic level in an ecosystem.

The ecological pyramids are of three categories-

1.Pyramid of numbers,

2.Pyramid of biomass, and

3.Pyramid of energy or productivity

1. Pyramid of Numbers

This deals with the relationship between the numbers of primary producers and consumers of different levels. Depending upon the size and biomass, the pyramid of numbers may not always be upright, and may even be completely inverted.

(a) Pyramid of numbers – upright

In this pyramid, the number of individuals is decreased from lower level to higher trophic level.

This type of pyramid can be seen in grassland ecosystem.

(b) Pyramid of numbers – inverted

In this pyramid, the number of individuals is increased from lower level to higher trophic level.

A count in a forest would have a small number of     large producers, for e.g. few number of big trees.   This is because the tree (primary producer) being

few in number and would represent the base of the pyramid and the dependent herbivores  (Example – Birds) in the next higher trophic level and it is followed by parasites in the next trophic level. Hyper parasites being at higher trophic level represents higher in number.

A pyramid of numbers does not take into account the fact that the size of organisms being counted in each trophic level can vary

the pyramid of number does not completely define the trophic structure for an ecosystem.

2. Pyramid of Biomass

In this approach individuals in each trophic level are weighed instead of being counted. This gives us a pyramid of biomass, i.e., the total dry weight of all organisms at each trophic level at a particular time.

Biomass is measured in g/m2.

 

(a) Upward -pyramid For most ecosystems on land, the pyramid of biomass has a large base of primary producers with a smaller trophic level perched on top

 

(b) Inverted pyramid-In contrast, in many aquatic ecosystems, the pyramid of biomass may assume an inverted form

3. Pyramid of Energy

To compare the functional roles of the trophic levels in an ecosystem, an energy pyramid is most suitable.

An energy pyramid, reflects the laws of thermodynamics, with conversion of solar energy to chemical energy and heat energy at each trophic level and with loss of energy being depicted at each  transfer to another trophic level.

Hence the pyramid is always upward, with a large energy base at the bottom.

POLLUTANTS AND TROPHIC LEVEL :-

Movement of these pollutants involves two main processes:

 

1. Bioaccumulation

refers to how pollutants enter a food chain. there is an increase in concentration of a pollutant from the environment to the first organism in a food chain.

 

2. Biomagnification

refers to the tendency of pollutants to concentrate as they move from one trophic level to the next.  there is an increase in concentration of a pollutant from one link in a food chain to another.

In order for biomagnification to occur, the pollutant must be: long-lived, mobile, soluble in fats, biologically active.

If a pollutant is not active biologically, it may biomagnify, but we really don’t worry about it much, since it probably won’t cause any problems Examples : DDT.

BIOTIC INTERACTION

The interaction between the organisms is fundamental for its survival and functioning of ecosystem as a whole.

Type of Biotic Interaction

1. Mutualism:

both species benefit.

Example: in pollination mutualisms, the pollinator gets food (pollen, nectar), and the plant has its pollen transferred to other flowers for cross-fertilization (reproduction).

 

2. Commensalism:

one species benefits, the other is unaffected.

Example: cow dung provides food and shelter to dung beetles. The beetles have no effect on the cows.

 

3. Competition:

both species are harmed by the interaction.

Example: if two species eat the same food, and there isn’t enough for both, both may have access to less food than they would if alone. They both suffer a shortage of food

 

4. Predation and parasitism:

one species benefits, the other is harmed.

Example : predation—one fish kills and eats ..parasitism: tick gains benefit by sucking blood; host is harmed by losing blood.

 

5. Amensalism :

One species is harmed, the other is unaffected.

Example: A large tree shades a small plant, retarding the growth of the small plant. The small plant has no effect on the large tree.

 

6. Neutralism :

There is no net benefit or harm to either species. Perhaps in some interspecific interactions, the costs and benefits experienced by each partner are exactly the same so that they sum to zero

 

BIOGEOCHEMICAL CYCLE

 

The elements or mineral nutrients are always in circulation moving from non-living to living and then back to the non-living components of the ecosystem in a more or less circular fashion. This circular fashion is known as biogeochemical cycling (bio for living; geo for atmosphere).

1. Nutrient Cycling:

The nutrient cycle is a concept that describes how nutrients move from the physical environment to the living organisms, and subsequently recycled back to the physical environment.

It is essential for life and it is the vital function of the ecology of any region. In any particular environment, to maintain its organism in a sustained manner, the nutrient cycle must be kept balanced and stable.

 

Types of Nutrient Cycle

Based on the replacement period a nutrient cycle is referred to as Perfect or Imperfect cycle.

A perfect nutrient cycle is one in which nutrients are replaced as fast as they are utilised.

Most gaseous cycles are generally considered as perfect cycles.

In contrast sedimentary cycles are considered relatively imperfect, as some nutrients are lost from the cycle and get locked into sediments and so become unavailable for immediate cycling.

Based on the nature of the reservoir, there are two types of cycles namely Gaseous and sedimentary cycle

Gaseous Cycle — where the reservoir is the atmosphere or the hydrosphere, and

Sedimentary Cycle — where the reservoir is the earth’s crust.

 

2. Gaseous Cycles:

Water Cycle (Hydrologic)

The hydrologic cycle is the continuous circulation of water in the Earth-atmosphere system which is driven by solar energy.

Water moves from one reservoir to another by the processes of evaporation,

transpiration, condensation, precipitation, deposition, runoff,

infiltration, and groundwater flow.

 

3. The Carbon Cycle

without carbon dioxide life could not exist, because it is vital for the production of carbohydrates through photosynthesis by plants. It is the element that anchors allorganic substances from coal and oil to DNA(deoxyribonudeic acid: the compound that caries genetic information) Carbon cycle involves a continuous exchange of carbon between the atmosphere and organisms. Carbon from the atmosphere moves to green plants by the process   of photosynthesis, and then to animals. By process of respiration and decomposition of dead organic matter it returns back to atmosphere.

 

4. The Nitrogen Cycle

an essential constituent of protein and is a basic building block of all living tissue. It constitutes nearly 16% by weight of all the proteins.

There is an inexhaustible supply of nitrogen in the atmosphere but the elemental form cannot be used directly by most of the living organisms needs to be ‘fixed’, that is, converted to ammonia, nitrites or nitrates, before it can be taken up by plants. on earth it is accomplished in three different ways:

(i) By microorganisms (bacteria and blue-green algae)

 

(ii) By man using industrial processes (fertilizerfactories) and

(iii) To a limited extent by atmospheric phenomenon such as thunder and lighting

The amount of Nitrogen fixed by man through industrial process has far

exceeded the amount fixed by the Natural Cycle.

As a result Nitrogen has become a pollutant which can disrupt the balance of

nitrogen. It may lead to Acid rain, Eutrophication and Harmful Algal Blooms.

Certain microorganisms are capable of fixing atmospheric nitrogen into

ammonium ions. These include free living nitrifying bacteria (e.g. aerobic

Azotobacter and anaerobic Clostridium) and symbiotic nitrifying bacteria living in  association with leguminous plants(pulse etc) and symbiotic bacteria    living in non leguminous root nodule plants (e.g. Rhizobium) as well as blue green algae (e.g. Anabaena, Spirulina).

Ammonium ions can be directly taken up as a source of nitrogen by some plants, or are oxidized to nitrites or nitrates by two groups of specialised bacteria:

Nitrosamines bacteria promote transformation of ammonia into nitrite. Nitrite isthen further transformed into nitrate by the bacteria Nitrobacter.

The nitrates synthesised by bacteria in the soil are taken up by plants and converted into amino acids, which are the building blocks of proteins.

These then go through higher trophic levels of the ecosystem.

During excretion and upon the death of all organisms nitrogen is returned to the soil in the form of ammonia.

Certain quantity of soil nitrates, being highly soluble in water, is lost to the system by being transported away by surface run-off or ground water. In the soil as well as oceans there are special denitrifying bacteria (e.g. Pseudomonas), which convert the nitrates/nitrites to elemental nitrogen. This nitrogen escapes into the atmosphere, thus  completing the cycle.

The periodic thunderstorms convert the gaseous nitrogen in the atmosphere to ammonia and nitrates which eventually reach the earth’s surface through precipitation and then into the soil to be utilized by plants.(Better if You Check Diagram)

5. Sedimentary Cycle

Phosphorus, calcium and magnesium circulate by means of the sedimentary cycle.

(a) Phosphorus Cycle

Phosphorus plays a central role in aquatic ecosystems and water quality.

Phosphorus occurs in large amounts as a mineral in phosphate rocks and enters the cycle from erosion and minning activities.

This is the nutrient considered to be the main cause of excessive growth of rooted and free-floating microscopic plants in lakes.

The main storage for phosphorus is in the earth’s crust.

On land phosphorus is usually found in the form of phosphates.

By the process of weathering and erosion phosphates enter rivers and streams that transport them to the ocean.

In the ocean once the phosphorus accumulates on continental shelves in the form of insoluble deposits

After millions of years, the crustal plates rise from the sea floor and expose the phosphates on land.

After more time, weathering will release them from rock and the cycle’s

geochemical phase begins again.

(b) Sulphur Cycle

The sulphur reservoir is in the soil and sediments where it is locked in organic

(coal, oil and peat) and inorganic deposits (pyrite rock and sulphur rock) in the

form of sulphates, sulphides and organic sulphur.

 

It is released by weathering of rocks, erosional runoff and decomposition of organic matter and is carried to terrestrial and aquatic ecosystems in salt solution.

The sulphur cycle is mostly sedimentary except two of its compounds hydrogen sulphide

(H2S) and sulphur dioxide (SO2) add a gaseous component to its normal sedimentary cycle.

Atmospheric sulphur dioxide is carried back to the earth after being dissolved in rainwater as weak sulphuric acid.

sulphur in the form of sulphates is take up by plants and incorporate through a series of metabolic processes into sulphur bearing amino acid which is incorporated in the  proteins of autotroph tissues. It then passes through the grazing food chain.

Sulphur bound in living organism is carried back to the soil, to the bottom of ponds and lakes and seas through excretion and decomposition of dead organic material.

 

SUCCESSION

a universal process of directional change in vegetation, on an ecological time scale. occurs when a series of communities replace one another due to large scale destruction either natural or manmade.

continously -one community replacing another community, until a stable, mature community develops.

The first plant to colonise an area is called the pioneer community. The final stage of succession iscalled the climax community.

The stage leading to the climax community are called successional stages

or seres. characterised by the following: increased productivity, the shift of nutrients from’ the reservoirs, increased diversity of organisms with increased niche development, and a gradual increase in the complexity of food webs.

Primary Succession

In primary succession on a terrestrial site the new site is first colonized by a few hardy pioneer species that are often microbes, lichens and mosses.

The pioneers through their death any decay leave patches of organic matter in which small animals can live.

The organic matter produced by these pioneer species produce organic adds during decomposition that dissolve and etch the substratum releasing nutrients to the substratum. Organic debris accumulates in pockets and crevices, providing soil  in which seeds can become lodged and grow.

As the community of organisms continues to develop, it becomes more diverse and competition increases, but at the same time new niche opportunities develops.

The pioneer species disappear as the habitat conditions change and invasion of new species progresses, leading to the replacement of the preceding community.

Secondary Succession

Secondary Succession occurs when plants recognize an area in which the climax community has been disturbed.

Secondary Succession  is the sequential development of biotic communities after the complete or partial destruction of the existing community.

This abandoned farmland is first invaded by hardy species of grasses that can survive in bare, sun-baked soil. These grasses may be soon joined by tall grasses and herbaceous plants.

These dominate the ecosystem for some years along with mice, rabbits, insects and seed- eating birds.

 

Eventually, some trees come up in this area, seeds of which may be brought by wind or animals. And over the years, a forest community develops. Thus an abandoned farmland over a period becomes dominated by trees and is transformed into a forest.

The differences between primary and secondary succession, the secondary succession starts on a well-developed soil already formed at the site. Thus secondary succession is relatively faster as compared to primary succession which may often require hundreds of years.

Autogenic and Allogenic Succession

When succession is brought about by living inhabitants of that community itself, the process is called autogenic succession, while change brought about by outside forces is known as allogenic succession.

Autotrophic and Heterotrophic succession

Succession in which, initially the green plants are much greater in quantity is known as autotrophic succession;  and the ones in which the heterotrophs are greater in quantity is known as heterotrophic succession.

Succession would occur faster in area existing in the middle of the large continent. This is because, here all prop gules or seeds of plants belonging to the different seres would reach much faster, establish and ultimately result in climax community.

 

 

Eutrophication is a syndrome of ecosystem, response to the addition of artificial or natural substances such as nitrates and phosphates through fertilizer, sewage, etc that fertilize the aquatic ecosystem.

The growth of green algae which we see in the lake surface layer is the physical identification of an Eutrophication.

Some algae and blue-green bacteria thrive on the excess ions and a population explosion covers almost entire surface layer is known as algal bloom.  Nitrogen testing is a technique to find the optimum amount of fertilizer required for crop plants. It will reduce the amount of nitrogen lost to the surrounding area.

 

 

HARMFUL ALGAL BLOOMS

Algae or phytoplankton are microscopic organisms that can be found naturally in coastal waters. They are major producers of oxygen and food for many of the animals that live in these waters.

Algal blooms can be any color, but the most common ones are red or brown.

Most algal blooms are not harmful but some produce toxins and do affect fish, birds, marine mammals and humans.

Use of algae

Most species of algae or phytoplankton serve as the energy producers at the base of the food web, without which higher life on this planet would not exist.

Why Red Tide is a misnomer?

“Red Tide” is a common name for such a phenomenon where certain

phytoplankton species contain pigments and “bloom” such that the human eye perceives the water to be discoloured.

Blooms can appear greenish, brown, and even reddish orange depending upon the type of organism, the type of water, and the concentration of the organisms.

The term “red tide” is thus a misnomer because blooms are not always red, they are not associated with tides, they are usually not harmful, and some species can be harmful or dangerous at low cell concentrations that do not discolour the water.

What are the causes of these blooms?

Two common causes are nutrient enrichment and warm waters.

 March 17, 2016 admin 0 Comments

Treaty		Signed/Into force	Major Points
Aarhus Convention on Access to information for public participation in decision making and access to justice in environmental matters	1998		Aarhus is a Danish city Adopted at the fourth ministerial conference in the ‘Environment for Europe’ process Links environmental rights and human rights   India – No
Vienna Convention for the protection of Ozone layer	1985/1988		Does not include legally binding reduction goals for the use of CFCs   At Vienna Conference
Montreal Protocol on substances that deplete the Ozone layer	1987/1989		It is a protocol to the Vienna Convention   “perhaps the single most successful international agreement” – Kofi Annan 196 states ratified Includes CFCs, HCFCs
Basel Convention on the Control of Transboundary Movements of Hazardous Wastes and their disposal	1989/1992		Particularly to prevent waste transfer from Developed to LDCs   175 parties Signed but not ratified: Afghanistan, Haiti, US
Rotterdam Convention on the Prior Informed Consent Procedure for Certain Hazardous Chemicals and Pesticides in international trade	1998/2004		Rotterdam is a city in Netherlands   Endosulfan is proposed to be added to the list
Stockholm Convention on persistence organic pollutants	2001/2004		173 parties
Bamako Convention	1991/1998		On the ban on the import into Africa and the Control of movement of Hazardous waste within Africa Negotiated by 12 nations of Organisation of African Unity at Bamako, Mali
The CBD Framework
Cartagena Protocol on Biosafety			Seeks to protect biological diversity from the potential risks posed by living modified organisms resulting from modern technology. The Protocol applies to the transboundary movement, transit, handling and use of all living modified organisms that may have adverse effects on the conservation and sustainable use of biological diversity, taking also into account risks to human health
Nagoya Protocol
For Conservation
CITES: Convention on International Trade in Endangered Species. AkaWashington Convention	1973/1975		Under IUCN. Trade in specimen should not threaten the survival of plants and animals. Only one species under it ‘Spix Macaw’ has become extinct in the wild.
Convention on Migratory Species aka Bonn Convention	1979/1983		To conserve terrestrial, marine and avian migratory species
Antarctic Treaty System	1959/1961		12 original members. HQ: Buenos Aires. India joined in 1983. Sets aside Antarctica as a scientific preserve and bans military activity there. First arms control treaty during the cold war.
International Whaling Commission	1946		Signed in Washington. Moratorium on whaling adopted in 1986. Following countries havnt adopted the moratorium: Norway, Iceland, Japan.
UN Convention to Combat Desertification	1994 (on the basis of Agenda 21)/1996		First and only internationally legally binding framework set up to address the problem of desertification. 194 2006: Int. Year of Deserts and Desertification. Non-parties: Iraq, Montenegro, Vatican Secretariat: Rome Meetings: 1st – Rome 1997, 9th – Buenos Aires, 2009

 

Sustainable Development

• Bruntland Report (1983) was the first publication and recognition of the term ‘Sustainable Development’
  • “meeting the needs of the present generation without compromising the needs of the future generation”
• Three pillarsof sustainable development (Bruntland)
  • Care and respect for People, Planet and Prosperity (Commercial Activities) <hence poverty alleviation, conservation and business development>
  • These three pillars are of equal importance
• SD is about avalue system. It is not a scientific formula.
• Thinking beyond pure self-gratification to awareness that harm to one will eventually be harm to all.
• Interconnectednessand interdependence of all things
• All three pillars have equal importance. Focus on only one of them will unbalance the whole
• SD is a necessity, not a luxury that we can afford to miss.

Questioning Development <too detailed; at times peripheral. Be choosy>

• Current practices must change
• Should shatter the ‘development’ myth. Simply economic growth will not create more jobs and more wealth for all.
• Steady-state economics. Economic growth is measured in terms of how much we produce and consume, and what we destroy in the process need not be included in the calculations.
• 20% of the world consumes 80% of its resources
• According to UNDP, consumption of goods and services in 1997 was twice that in 1975 and six times more than in 1950.
• An estimated 1 billion people still do not have the means to meet their basic needs.
• Inequalities are increasing. The assets of world’s three richest men are greater than the combined national product of 48 poorest countries.
• Higher crime rates are associated with wider income gaps
• Jobless growth.
• Under-nutrition is still a huge problem among children

Economic Growth and Sustainability

• Over-consumption has led to depletion of resources
• Main environmental threats
  • Depletion of resources
  • Global warming
  • Expansion of waste arising from production and consumption
  • Population pressure
  • Pollution
  • Loss of biodiversity and extinction of species.
• Green National Income Account
  • Conventional national income accounting does not capture the environmental degradation due to production and consumption
  • This omission leads to misrepresentation of improvements in social welfare
  • Since there is no market for many environmental resources, it is difficult to place monetary values on them
  • Index of Sustainable Economic Welfare: adjusts the national income to make an allowance for defensive spending (i.e. that incurred in cleaning up for pollution and other forms of environmental damage)
• Economic Sustainability
  • Calls for reforms in the manner that we conduct our economic activity
  • Removing unfair trade barriers and subsidies that harm the environment
  • Upholding the polluter pays principle
  • Tax not on labour but on consumption <already there in the form of indirect taxes>
  • Pricing products in terms of value they have deducted from the common natural base
  • Increase resource productivity
• Sustainable agriculture
  • Use of practices and methods to maintain/enhance the economic viability of agricultural production, natural resource base, and other ecosystems which are influenced by agricultural activities
  • Minimizing the adverse impact on the natural resources base
  • Flexible farming systems to manage the risks associated with climate and markets

Ecological Sustainability

• Sustainable forest management
  • ‘Forest Principle’ adopted at the 1992 Rio Summit
  • In 2007, GA adopted the Non Legally Binding Instrument on All Types of Forests. The instrument is the first of its kind and is committed to promote SFM by bringing all stakeholders together
  • Ministerial Conference on Protection of Forests in Europe defined SFM as the attainment of balance between society’s increasing demands for forest products and benefits, and the preservation of forest health and diversity.
  • Forest managers must assess and integrate a wide array of sometimes conflicting factors to produce sound forest plans
  • Ecosystems approachhas been adopted by the CBD. The CBD definition of Ecosystems Approach is known as the Malawi Principles.
  • Ecosystems Approach is a strategy of management of land, water and living resources in a way that promotes conservation and sustainable use in an equitable way. Focused on use of scientific methodologies for each level of biological organisation and their interaction.
  • SFM was recognised by the parties to CBD in 2004 to be a concrete means of applying the Ecosystems Approach to forest ecosystems
• Objectives of SFM
  • Maintain environmental stability through preservation of ecological balance that has been adversely affected due to the depletion of forest cover
  • Preserve the natural heritage of the country
  • Improve productivity of forests
  • Protecting through cooperation with local communities on the principle of Joint Forest Management
• India
  • One of the 12 mega biodiversity countries of the world
  • National Forest Policy 1988emphasizes environmental stability and maintenance of ecological balance
  • Existing infrastructure for forest protection is inadequate
  • Surveys not carried out in many areas. Question of tribal rights
  • Protect from forest fires
• Integrated Forest Protection Scheme
  • 10^thFYP. In all States and UTs
  • Formed by merger of two 9^thFYP schemes: ‘Forest Fire Control and Management’ and ‘Bridging of Infrastructure Gaps in the Forestry Sector in the North Eastern Region and Sikkim’
  • Components
    • Infrastructure development: survey and demarcation, strengthening the infrastructure for Forest Protection Division
    • Forest fire control and management
  • Implementing agencies
    • Central Component: Forest Protection Division, MoEF; Forest Survey of India, Dehradun; Central institutions like Indian Council of Forestry Research and Education (Dehradun), IIFM (Bhopal) etc shall be involved
    • State Component: Forest dept of the concerned state/UT

Social Sustainability

• Fairness in the access to and benefits from the Earth’s resources
• Impact of poverty on environment/Environment and poverty are related issues
• Diverting resources to non-productive areas
• Health and SD
  • Environment and public health are inter-related
• Agenda 21was adopted at the UN Conference on Environment and Development (UNCED) [Earth Summit] in 1992
  • It also places particular emphasis on the need to take health considerations into account in planning for SD
• Urbanisation
• Need for holistic approach

Water and SD

• Agriculture consumes nearly 70 pc of water consumption worldwide, industry -22 pc and household activities – 8 pc [WDR, 2010]
• Geographical distribution of water: just nine countries account for 60 pc of all available freshwater supplies
• Industrial use takes about 60 pc of water in rich countries and 10 pc in the rest.
• Suggestions
  • Use of sea water
  • Judicial use of freshwater
  • Development of salt-resistant crops

SD in a globalising world

• Globalisation is increasing the gap between the rich and the poor
• It has to be steered so that it serves not only the commercial interests but social needs of development
• Mechanisms to safeguard trade and livelihoods, especially in developing countries, must be evolved and negotiated to make globalisation an effective vehicle of SD
• Industrialised countries must continue to assist the developing countries as well as promote trade
• Environment and social causes must not be used selectively to erect trade barriers against developing countries

 

 

Fresh water ecosystems- The salt content of fresh bodies is very low, always less than 5 ppt  (parts per thousand). E.g lakes, ponds, pools, springs, streams, and rivers

Marine ecosystems – the water bodies containing salt concentration equal to or above that of sea water (i.e., 35 ppt or above). E.g shallow seas and open ocean   Brackish water ecosystems- these water bodies have salt content in between 5 to 35 ppt. e.g. estuaries, salt marshes, mangrove swamps and forests.

 

AQUATIC ORGANISMS

The aquatic organisms are classified on the basis Of their one of occurrence and their ability to cross these zones. can be classified on the basis of their life form or location into five groups

1. Neuston:

These are unattached organisms which live at the air-water interface such as floating plants, etc.

Some organisms spend most of their lives on top of the air-water interface such as water striders, while others spend most of their time just beneath the air-water interface and obtain most of their food within the water.

E.g., beetles and back-swimmers.

2. Periphyton:

These are organisms which remain attached to stems and leaves of rooted plants or substances emerging above the bottom mud such as sessile algae and their associated group of animals.

3. Plankton

This group includes both microscopic plants like algae (phytoplankton) and

animals like crustaceans and protozoans (zooplankton) found in all aquatic

ecosysteins, except certain swift moving waters

The locomotory power of the planktons is limited so that their distribution is

controlled, largely, by currents in the aquatic ecosystems.

4. Nekton:

This group contains animals which are  swimmers.

The nektons are relatively large and powerful as they have to overcome the water currents.

5. Benthos:

The benthic organisms are those found living in the bottom of the water mass.

Practically every aquatic ecosystem contains well developed benthos

Factors Limiting the Productivity of Aquatic Habitats

1. Sunlight :

Sunlight penetration rapidly diminishes as it passes down the column of water.

The depth to which light penetrates a lake determines the extent of plant distribution.

Based on light penetration and plant distribution they are classified as photic and aphotic zones

Photic zone:

It is the upper layer of the aquatic ecosystems, up to which light penetrates and within which photosynthetic activity is confined.

The depth of this zone depends on the transparency of water.

photic (or .”euphotic”) zone is the lighted and usually well-mixed portion that extends from the lake surface down to where the light level is 1% of that at the surface.

Aphotic zone:

The lower layers of the aquatic ecosystems, where light penetration and plant growth are restricted forms the aphotic zone.

Only respiration activity takes place.(photic-both respiration and photosynthesis take place )

Aphotic zone is positioned below the littoral and photic zones to bottom of the lake where light levels are too low for photosynthesis.

This deep, unlit region is also known as the profundal zone.

Dissolved oxygen:

Oxygen enters the aquatic ecosystem through the air water interface and by the photosynthetic. average concentration of dissolved oxygen as 10 parts per million by weight.

Dissolved oxygen escapes the water body through air-water interface and through respiration of organisms (fish, decomposers, zooplanktons, etc )

The amount of dissolved oxygen retained in water is also influenced by temperature.

Other limiting factors which influence on aquatic productivity are

Transparency:

Transparency affects the extent of light penetration.

Suspended particulate matters such as clay, silt, phytoplankton, etc make the water turbidity. Consequently it limits the extent of light penetration and the photosynthetic activity in a significant way.

Temperature:

The water temperature changes less rapidly than the temperature of air because water has a considerably higher specific heat than air.

Since water temperatures are less subject to change, the aquatic organisms have narrow temperature tolerance limit.

 

Any – body of standing water, generally large enough in area and depth, irrespective of its hydrology, ecology, and other characteristics is generally known as lake.

Ageing of Lakes

The nutrient enrichment of the lakes promotes the growth of algae, aquatic plants and various fauna. This process is known as natural eutrophication.

Similar nutrient enrichment of lakes at an accelerated rate is caused by human activities and the consequent ageing phenomenon is known as ‘cultural eutrophication’.

In India, natural lakes (relatively few) mostly ile in the Himalayan region, the floodplains of Indus, Ganga and Brahmaputra.

Lake ‘Sudarshan’ in Gujarat’s Girnar area was perhaps the oldest man-made lake in India, dating back to 300 BC.

Lakes are also classified on the basis of their water chemistry. Based-on the levels of salinity, they are known as Freshwater, Brackish or Saline lakes (similar to that of classification of aquatic ecosystem).

On the basis of their nutrient content, they are categorized as Oligotrophic (very low nutrients), Mesotrophic (moderate nutrients) and Eutrophic (highly nutrient rich).

Removal of the nutrients from a lake

• Flushing with nutrient-poor waters.
• Deep water abstraction.
• On-site P-elimination by flocculation/flotation with water backflow, or floating Plant
• NESSIE with adsorbents.
• On-site algae removal by filters and P-adsorbers.
• 0n-site algae skimming and separator thickening.
• Artificial mixing / Destratification (permanent or intermittent).
• Harvest of fishes and macrophytes.
• Sludge removal

EUTROPHICATION

a syndrome of ecosystem, response to the addition of artificial or natural substances such as nitrates and phosphates through fertilizer, sewage, etc that fertilize the aquatic ecosystem.

The growth of green algae which we see in the lake surface layer is the physical identification of an Eutrophication.

Some algae and blue-green bacteria thrive on the excess ions and a population explosion covers almost entire surface layer is known as algal bloom.  Nitrogen testing is a technique to find the optimum amount of fertilizer required for crop plants. It will reduce the amount of nitrogen lost to the surrounding area.

 

 

HARMFUL ALGAL BLOOMS

Algae or phytoplankton are microscopic organisms that can be found naturally in coastal waters. They are major producers of oxygen and food for many of the animals that live in these waters.

Algal blooms can be any color, but the most common ones are red or brown.

Most algal blooms are not harmful but some produce toxins and do affect fish, birds, marine mammals and humans.

Use of algae

Most species of algae or phytoplankton serve as the energy producers at the base of the food web, without which higher life on this planet would not exist.

Why Red Tide is a misnomer?

“Red Tide” is a common name for such a phenomenon where certain

phytoplankton species contain pigments and “bloom” such that the human eye perceives the water to be discoloured.

Blooms can appear greenish, brown, and even reddish orange depending upon the type of organism, the type of water, and the concentration of the organisms.

The term “red tide” is thus a misnomer because blooms are not always red, they are not associated with tides, they are usually not harmful, and some species can be harmful or dangerous at low cell concentrations that do not discolour the water.

What are the causes of these blooms?

Two common causes are nutrient enrichment and warm waters.

 

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 are the materials or factors, which cause adverse effect on the natural quality of any component of the environment.

Classifications

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

• Primary pollutants: These persist in the form in which they are added to the environment e.g. DDT, plastic.
• 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.

2. According to their existence in nature.

• Quantitative Pollutants: These occur in nature and become pollutant when their concentration reaches beyond a threshold level. E.g. carbon dioxide, nitrogen oxide.
• Qualitative Pollutants: These do not occur in nature and are man-made. E.g. fungicides, herbicides, DDT etc.

3. According to their nature of disposal.

• Biodegradable Pollutants: Waste products, which are degraded by microbial action. E.g. sewage.
• Non-biodegradable Pollutants: Pollutants, which are not decomposed by microbial action. E.g. plastics, glass, DDT, salts of heavy metals, radioactive substances etc

4. According to origin

• Natural
• Anthropogenic

 

AIR POLLUTION

aggravated because of four developments:

Increasing traffic, growing cities, rapid economic development, and industrialization

contamination of air by the discharge of harmful substances

 

Major air pollutants and their sources

1. 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.

2. Carbon dioxide (CO2)

principle greenhouse gas

3. Chloroflorocarbons (CFC)

• gases that are released mainly fromair-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.

 

4. Lead

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

affects children in particular. cause nervous system damage and digestive problems and, in some cases, cause cancer.

 

5. Ozone

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

 

6. Nitrogen oxide (Nox)

• 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.

 

7. Suspended particulate matter (SPM)

• consists of solids in the air in the form of smoke, dust, and vapour that can remain suspended for extended periods
• The finer of these particles when breathed in can lodge in our lungs and cause lung damage and respiratory problems.

 

8. Sulphur dioxide (S02)

• a gas produced from burning coal, mainly in thermal power plants.
• Some industrial processes, such as production of paper and smelting of metals, produce sulphur dioxide.
• a major contributor to smog and acid rain.
• Sulphur dioxide can lead to lung diseases

 

9. Smog

• a combination of the words fog and smoke. Smog is a condition of fog that had soot or smoke in it.
• interaction of sunlight with certain chemicals in the atmosphere.
• primary components of photochemical smog is ozone.
• Ozone is formed through a complex reaction involving hydrocarbons, nitrogen oxides, and sunlight. It is formed when pollutants released from gasoline, diesel- powered vehicles and oil-based solvents react with heat and sunlight from biofuels, the four most serious pollutants are particulates, carbon monoxide, polycyclic organic matter, and formaldehyde

 

Pollutants

1. i) Volatile organic compounds

The main indoor sources are perfumes, hair sprays, furniture polish, glues, air

fresheners, moth repellents, wood preservatives, and other products.

 

1. ii) Biological pollutants

It includes pollen from plants, mite, and hair from pets, fungi, parasites, and some bacteria.

iii) Formaldehyde

Mainly from carpets, particle boards, and insulation foam. It causes irritation to the eyes and nose and allergies.

1. iv) Radon

It is a gas that is emitted naturally by the soil. Due to modern houses having poor ventilation, it is confined inside the house and causes lung cancers.

 

Fly Ash

Ash is produced whenever combustion of solid material takes place.

Composition

1. Aluminium silicate (in.large amounts)
2. silicon dioxide (Si02) and
3. Calcium oxide (Ca0).

Fly ash particles are oxide rich and consist of silica, alumina, oxides of iron, calcium, and magnesium and toxic heavy metals like lead, arsenic, cobalt, and coppers

 

Policy measures of MoEF:

• The Ministry of Environment and Forests vide its notification in 2009, has made it mandatory to use Fly Ash based products in all construction projects, road embankment works and low lying land filling works within 100 kms radius of Thermal Power Station.
• To use Fly Ash in mine filling activities within 50 kms radius of Thermal Power Stations.
• Arresters: These are used to separate particulate matters from contaminated air.
• Scrubbers: These are used to clean air for both dusts and gases by passing it through a dry or wet packing material.

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).

National Ambient Air Quality Standards (NAAQS) were notified in the year 1982, duly revised in 1994 based on health criteria and land uses .

The NAAQS have been revisited and revised in November 2009 for 12 pollutants, which include. sulphur dioxide (S02), nitrogen dioxide (NO2), particulate matter having size less than 10 micron

(PM10),particulate matter having size less than 2.5micron (PM2.5), ozone, lead, carbon monoxide (CO), arsenic, nickel, benzene, ammonia, and. Benzopyrene.

WATER POLLUTION

Addition of certain substances to the water such as organic, inorganic,

biological, radiological, heat, which degrades the quality of water so that it

becomes unfit for use.

Putrescibility is the process of decomposition of organic matter present in water by microorganisms using oxygen.

Water having DO (dissolved oxygen)  content below 8.0 mg/L may be

considered as contaminated.  Water having DO content below. 4.0 mg/L is

considered to be highly polluted.

Water pollution by organic wastes is measured in terms of Biochemical Oxygen Demand-(BOD). BOD is the amount of dissolved oxygen needed by bacteria in decomposing the organic wastes present in water.

Chemical oxygen demand (COD) is a slightly better mode used to measure pollution load in water. It is the measure of oxygen equivalent of the requirement of oxidation of total organic matter (i.e. biodegradable and non- biodegradable) present in water.

A cripling deformity called Minamata disease due to consumption of fish captured from mercury contaminated Minamata Bay.

Water contaminated with cadmium can cause itai itai disease also called ouch-ouch disease (a painful disease of bones and joints) and cancer of lungs and liver.

The compounds of lead cause anaemia, headache, loss of muscle power and bluish line around the gum

Excess nitrate in drinking water reacts with hemoglobin to form non -functional met haemoglobin, and impairs oxygen transport.  This condition  is  called methaemoglobinemia or blue baby syndrome.

Over exploitation of ground water may lead to leaching of arsenic from soil and rock sources and contaminate ground water.  Chronic exposure to arsenic causes black foot disease. It also causes diarrhoea,-peripheral neuritis, hyperkerotosis and also   lung and skin cancer.

SOIL POLLUTION

Industrial waste includes chemicals such as mercury, lead, copper, zinc, cadmium, cynides, thiocynates, chromates, acids, alkalies, organic substances etc

Four R’s: Refuse, Reduce, Reuse, and Recycle

NOISE POLLUTION

Sound is measured in decibels (dB). An increase of about 10 dB is approximately double the increase in loudness.

A person’s hearing can be damaged if exposed to noise levels over 75 dB over a prolonged period of time.

The World Health Organization recommends that the sound level indoors should be less than 30 dB.

Ambient Noise Level Monitoring –   Noise Pollution (Control and Regulation) Rules, 2000 define ambient noise levels for various areas as follows-

1. Industrial Area—75DB to 70Db (Day time-6am to 10pm and night time 10pm to 6am ..75 is day time and 70 is night time)
2. Commercial Area–65 to 55
3. Residential Area–55 to 45
4. Silence Zone– 50  to 40

• The Government of India on Mar 2011 launched a Real time Ambient Noise Monitoring Network.
• Under this network, in phase- I, five Remote Noise Monitoring Terminals each have been installed in different noise zones in seven metros (Delhi, Hyderabad, Kolkata, Mumbai, Bangalore, Chennai and Lucknow).

In Phase II another 35 monitoring stations will be installed in the same seven cities.

Phase III will cover installing 90 stations in 18 other cities.

Phase-III cities are Kanpur, Pune, Surat, Ahmedabad,  Nagpur, Jaipur,  Indore,

Bhopal, Ludhiana, Guwahati, Dehradun, Thiruvananthpuram, Bhubaneswar,

Patna, Gandhinagar, Ranchi, Amritsar and Raipur.

Silence Zone is an area comprising not less than 100 metres around hospitals, educational institutions, courts, religious places or any other t area declared as such by a competent authority.

 

 

RADIO ACTIVE POLLUTION

Non-ionising radiations affect only those components which absorb them and have low penetrability.   They include short-wave radiations such as ultraviolet rays, which forms a part of solar radiation. Sunburns is due to these radiation Ionising radiations have high penetration power & cause breakage of macro molecules

They include X-rays, cosmic rays and atomic radiations -(radiations emitted by radioactive elements

Alpha particles, can be blocked by a piece of paper and human skin.

Beta particles can penetrate through skin, while can be blocked by some pieces of glass and metal.

Gamma rays can penetrate easily to human skin and damage cells on its way through, reaching far, and can only be blocked by a very thick, strong, massive piece of concrete radium-224, uranium-238, thorium-232, potassium-40, carbon-14, etc.

The nuclear arms use uranium-235 and plutonium-239 for fission and hydrogen or lithium as fusion material

The radio nuclides with long half-time are the chief source of environmental radioactive pollution.