Unit 5: Environmental Pollution

• Environmental pollution: types, causes, effectsand controls; Air, water, soil and noise pollution

• Nuclear hazards and human health risks

• Solid waste management: Control measures ofurban and industrial waste.

• Pollution case studies.

DefinitionPollution is an undesirable change inphysical, chemical and biologicalcharacteristics of our land, air or watercaused by excessive accumulation ofpollutants (i.e. Substances which causepollution).

KINDS OF POLLUTIONThe pollution is of four major types namelyair pollution, water pollution, landpollution and noise pollution.

In terms of origin it may be natural oranthropogenic (man-made).

POLLUTION

Degradation of air quality and naturalatmospheric condition constitute airpollution. The air pollutant may be a gas orparticulate matter.

Air pollutants and their effectsParticulate matter – it comprises of smallsuspended particles such as soot, dust, pesticides,etc., and biological agents such as spores, pollenand dust mites. It causes respiratory ailments suchas asthma, chronic bronchitis, etc.,

Carbon monoxide – is a product of incompletecombustion of fossil fuels in automobiles. It ishighly poisonous to most animals. When inhaled,carbon monoxide reduces the oxygen carryingcapacity of blood.

AIR POLLUTION

Hydrocarbons – hydrocarbons such as methane,are evolved from soil microbes (methanogens) inflooded rice fields and swamps. They are alsogenerated during the burning of coal and petroleumproducts.

Sulphur dioxide – is released from oil refineriesand ore smelters which use the sulphur containingfuels. It causes harmful effects on plants and animals.It causes chlorosis (loss of chlorophyll) and necrosis(localised death of tissues). In human, it causes healthproblems such as asthma, bronchitis and emphysema.

Nitrogen oxides – It causes reddish brown haze(brown air) in traffic congested city air whichcontributes to heart and lung problems.

Air pollutants and their effects

Photochemical smog – Smog is a mixture ofsmoke and fog. It is formed in the atmosphereunder the influence of sunlight by thephotochemical reactions of hydrocarbons, oxidesof nitrogen and oxygen, resulting in the formationof PAN (Peroxy Acetyl Nitrate).

PAN damages the chlorophyll and thus reducesphotosynthesis and growth. It also causes acuteirritation of eyes and throat. Visibility of thesurrounding is reduced due to smog.

Acid rain – gases such as Sulphur di oxide andNitrogen oxides are oxidized to form sulphuric andnitric acids along with water, and precipitate asacid rain. It damages building materials, plants andanimals. It also makes the soil acidic.

Secondary effects of air pollution

1. The particulates emitted by industries shouldbe controlled by devices such as scrubbers,precipitators and filters.

2. Use of unleaded or low sulphur fuel is to beencouraged.

3. Shifting to non-conventional sources ofenergy (e.g solar energy, hydel energy, tidalenergy, etc.,) in order to reduce thedependance of conventional sources.

4. Smoking in public places should beprohibited, because the cigarette smokecontains carcinogens such as benzopyrene.An average smoker runs the risk ofdeveloping heart and lung diseases.

5. Planting of trees along the road sides andaround industrial areas.

Control of air pollution

Water pollution is defined as theadding of unwanted substances orthe change of physical andchemical characteristics of water inany way which makes it unfit forhuman consumption.

It is caused by waste products ofindustries (effluents), domesticsewage, oil spillage, agriculturaland industrial run off etc.,

WATER POLLUTION

Industrial wastes –The industrialeffluents containing heavy metalsand chemicals such as arsenic,cadmium, copper, chromium,mercury, zinc, nickel, etc,. aredirectly released into the waterbodies such as lakes, ponds andrivers without proper treatment.

These wastes contaminate the waterbodies and make them unsuitablefor human consumption.

Hot water is another noted pollutantfrom industries.

Sources and effects of water pollution

1. Many industries use water as a coolantfor the machinery and release of hotwaste water into the water bodiescausing thermal pollution which affectboth the plant and animal life.

2. The surface run off - the surface run offfrom agricultural land is contaminatedwith pesticides and residues of inorganicfertilizers.

3. The run off from urban and industrialare rich in organic and inorganiccompounds. These pollutantscontaminate both surface and groundwater resources.

Sources and effects of water pollution..

4. Oil spills – An oil spill is an accidentaldischarge of petroleum products in oceansand estuaries from capsized oil tankers,offshore drilling and exploration operations.It can cause drastic damage to the marineand coastal bio diversity.

5. Domestic Sewage – It is rich in organicmatter and detergents. Decomposition oforganic matter increases the nutrientcontent of the water bodies.

6. Availability of excess nutrients results inalgal bloom on the surface of waterresulting in the deficiency of oxygen content(BOD – Biological Oxygen Demand). This inturn leads to the death of aquaticorganisms. This process is known asEutrophication.

Sources and effects of water pollution...

1. Sewage treatment plants should beinstalled to treat sewage beforereleasing into water bodies.

2. Excessive use of pesticides, herbicidesand fertilizers should be avoided.

3. Biological control of insect pests andorganic farming is to be followed inorder to reduce the dependence onpesticides and inorganic fertilizers.

4. By legislation and strict enforcement.

5. By creating social awareness amongpeople about the water pollution andthe need for pure water.

Control of water pollution

Soil pollution is theunfavorable alteration of soilby the addition or removal ofsubstances which decreasesoil productivity and groundwater quality.

It usually results fromdifferent human activities likedumping of waste, use of agrochemicals, mining operationsand urbanization.

SOIL POLLUTION

• The industrial solid waste and sludgecontain toxic organic and inorganiccompounds as well as heavy metals.

• The radio active waste from nuclear powerplants and nuclear explosions alsocontaminate the soil.

• Fly ash contains fine particulates which arereleased from thermal power plants. Itsettle on the ground and cause pollution.

• The domestic waste is rich in organicmatter and undergo decomposition.

• The hospital waste contains a variety ofpathogens that can seriously affect humanhealth.

SOIL POLLUTION : Causes and effects

Agricultural chemicals such aspesticides, insecticides andinorganic fertilizers may pollutedrinking water and can changethe chemical properties of thesoil adversely affecting the soilorganisms.

SOIL POLLUTION : Causes and effects

• Management of soil wastes includecollection and categorization of wastes.Recovery of resources like scrap metals,plastics, etc., for recycling and reuse andsafe disposal with a minimumenvironmental hazards is to be followed.

• Other notable methods of waste disposalinclude incineration (burning in thepresence of oxygen) and pyrolysis(burning in the absence of oxygen).

• Afforestation and reforestation should beundertaken on a large scale to preventsoil erosion and loss of soil nutrients.

CONTROL OF SOIL POLLUTION

The emission of protons, electronsand electromagnetic radiationsreleased by the disintegration ofradioactive substances such asradium, thorium, uranium, etc,. causeair, water and land pollution.

Effects :-• The ionising radiations can cause

mutations.

• Strontium-90 accumulates in bonescausing bone cancer.

• Iodine-131 can damage bonemarrow, spleen, lymph nodes andcan cause leukemia (blood cancer).

RADIOACTIVE POLLUTION

• Care should be taken to preventthe leakage of radioactivesubstances from nuclearreactors.

• Radioactive wastes should bedisposed off safely.

• Strict measures should befollowed in the constructionand maintenance of nuclearpower plants to prevent nuclearaccidents.

• Control or prevention of nucleartests.

RADIOACTIVE POLLUTION: PREVENTIVE MEASURES

• Noise may be defined as anunwanted and unpleasantsound that may haveadverse effects on animalsand humans.

• The unit of sound level isdecibels (db).

• Noise level above 120 db isconsidered harmful tohuman beings.

NOISE POLLUTION

Sources• The different sources associated with

noise pollution are industrial machinery,road, rail and air transport,loudspeakers, construction equipments,household appliances, crackers, etc,.

Effects• Noise seriously affects heartbeat,

breathing, and can cause constriction ofblood vessels.

• It can cause headache, sleeplessness,irritability and may seriously affect theproductive performance of human.

NOISE POLLUTION..

• Loud noises (above 130 db) can cause damage to theear drum, hair cells of cochlea (organ of hearing) andthereby resulting in temperory or permanent loss ofhearing.

• It can also seriously affect the concentration of studentswhile learning.

NOISE POLLUTION…

• The industries should be establishedaway from residential areas.

• Trees should be planted along roadsideor highways to reduce noise levels.

• The industrial machinery and motorvehicles should be properly maintainedin order to minimize the noise.

• The use of loudspeakers and burstingof crackers should be restricted.

• Effort must be made to createawareness among people about theharmful effects of noise and the needto control it.

NOISE POLLUTION: Control measures

• India produces 55 million tons of municipal solid waste annually atpresent.

• Per capita generation of waste varies from 200 gm to 600 gm percapita / day.

• Average generation rate at 0.4 kg per capita per day in towns.

• Collection efficiency ranges between 50% to 90% of the solid wasteare generated.

Waste Generation in India

• Solid or semi-solid material (includinggases and liquids in containers) whichare non soluble in nature are solidwaste.

• Solid waste includes agriculturalrefuse, demolition waste, industrialwaste, mining residues, municipalgarbage, sewage sludge, etc.

WHAT IS SOLID WASTE?WASTE is a any material,Thrown away” regarded asuseless and unwanted(at a certain time and place)

Bio-degradable: can be degradedpaper, wood, fruits and others)

Non-biodegradable: cannot bedegraded plastics, bottles, old-machines, containers and others)

TYPES OF SOLID WASTE• Solid waste can be classified into different

types depending on their source:• Household waste or municipal waste:

includes food, paper, cardboard, plastic,textiles, leather, glass, metal, ashes,electronics waste etc.

• Industrial waste: includes toxic chemicals,oil, debris from construction site,packaging waste, ashes etc.

• Biomedical waste or hospital waste:medicine bottles, expired medicines,syringes, medical instruments such asscissors, blades etc.

Agricultural waste: includes pesticides,crops, water coming from the fields alsoconsists of small amount of toxic chemicals.

Nuclear waste: includes radioactivesubstances coming from reactors, fuel(uranium, thorium, plutonium etc). Itshighly dangerous and requires properdisposal.

Hazardous waste: includes toxic chemical,acids, corrosive, ignitable and reactivematerials, gases etc.

TYPES OF SOLID WASTE

SOLID WASTE COMPOSITION

• Per capita waste generationincreasing by 1.3% per annum

• With urban population increasingbetween 3 – 3.5% per annum

• Yearly increase in waste generation isaround 5% annually India produces42.0 million tons of municipal solidwaste annually at present.

• Per capita generation of waste variesfrom 200 gm to 600 gm per capita /day.

• Collection efficiency ranges between50% to 90% of the solid wastegenerated.

MAGNITUDE OF PROBLEM

• 30% - 55% Compostable / Bio-degradable Matter

(can be converted into manure)

• 40% - 45% Inert material(to go to landfill)

• 5% - 10% Recyclable materials(Recycling)

• These percentages vary fromcity to city depending on foodhabits

Municipal Solid Waste in India

New Delhi:Capital of India

HOSPITAL WASTES

Non Infectious Infectious

Non Sharps Sharps

Solids Liquids

Incinerable Non Incinerable(Autoclave, Microwave)

Biodegradable Non Biodegradable

COLOUR CODING

COLOURCODING

TYPE OFCONTAINER

WASTECATEGORY

TREATMENT OPTIONSas per Schedule I

Yellow Plastic Bag Cat.. 1, 2, 3and 6

Incineration / deepburial

Red Disinfectedcontainer /Plastic Bag

Cat. 3, 6, and 7 Autoclaving /Microwaving / ChemicalTreatment

Blue / WhiteTranslucent

Plastic Bag /puncture proofcontainer

Cat. 4, Cat. 7 Autoclaving /Microwaving / Chemicaltreatment anddestruction shredding

Black Plastic Bag Cat. 5, 9 and10 (Solid)

Disposal in securedlandfill

E-waste

• E-waste comprises ofwaste electronicsgoods which are not fitfor their originallyintended use.

• Such electronics goodsmay be television,telephones, radios,computers, printers,fax machines, DVDsand CDs etc.

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TOXIC CHEMICALS IN E-WASTE

• Lead – Affects Central andPeripheral Nervous system, KidneyDamage, Inhibits oxygen carryingcapacity of blood

• Cadmium – Toxic, stores in Kidney,Neural damage

• Mercury – Chronic damage to brain,Respiratory and skin disorders

• Chromium – DNA disorders, Asthma• Barium – Muscle weakness, kidney

damage• Beryllium – Lung cancer,

beryllicosis, skin diseases• PVC – Hormonal problems,

Reproductive issues

• Massive awareness to consumers• Setting up of more collection centers and collection points• Manufactures responsibility to provide good standard materials and

assurance for recycling• Fair Trade principles• More recycling units by providing subsidized financial supports• Proper training to Workers dealing recycling units• Ban on importing e-waste from other countries• Proper monitoring and evaluation system by the regulators in all levels• Sell or dump of e-waste only to government authorized recyclers• Green and energy efficient devices by the manufactures• Donate used electronics to charitable organizations• Recovery of valuable metals like Cu, Al, Au, and Ag through recycling• Use of available best strategies

Methods of Waste Disposal• Landfills• Incineration• Source reduction• Composting• Recycling

Land filling• Most municipal solid waste in

India is deposited in landfills• It is the most traditional method

of waste disposal• Source of groundwater pollution

• Waste is directly dumped intodisused quarries, mining voids orborrow pits.

• It is generally used for domestic waste

Incinerationl Prior to 1940, incineration was common in North America

and western Europe.l Many incinerators were eliminated because of foul odors

and gritty smokel Currently, about 15% of municipal solid waste is

incinerated.

IncinerationPros:– Reduce volume 90%,

weight 75%– Heat from burning

converted to electricity

Cons:• Create air pollution• Concentrates toxins in ash• More costly than landfills,

as long as space available

Composting• Harnessing natural decomposition to

transform organic material into compost

• Materials such as plants, food scraps, andpaper products can be decomposed intothe organic matter.

• The organic matter that is produced fromrecycling can be agricultural uses.

• Usually this method of recycling is done byputting the materials in a container and letto stay there until it decomposes.

• Ocean dumping is the dumping orplacing of materials in the ocean,often on the continental shelf.

• A wide range of materials isinvolved, including carbageconstruction and demolition debris,sewage sludge, dredge material,waste chemicals, and nuclearwaste.

• Sometime hazardous and nuclearwaste are also disposed but theseare highly dangerous for aquatic lifeand human life also.

OCEAN DUMPING

ADVANTAGES• Convenient• Inexpensive• Source of nutrients for

fishes and marinemammals.

• Vast amount of space isavailable.

• All type of wastes aredisposed.

DISADVANTAGES• There are three main direct public

health risks from ocean dumping:• Occupational accidents, injuries

and exposures• exposure of the public to

hazardous or toxic materialswashed up on beach sand.

• human consumption of marineorganisms that have beencontaminated by ocean disposal.

• Highly dangerous for aquatic life.

Recycling• It is basically processing or

conversion of a waste item intousable forms.

• Recyclable materials includemany kinds of glass, paper, metal,plastic, textiles, and electronics.

• But recycling is not a solution tomanaging every kind of wastematerial.

• For many items like plastic bags,plastic wrap, yogurt cups,margarine container etc.recycling technologies areunavailable or unsafe.

RecyclingBenefitsl Saves money, raw materials, and

land.

l Encourages individual responsibility.

l Reduces pressure on disposalsystems.

l Japan recycles about half of allhousehold and commercial wastes.

l Lowers demand for raw resources.

l Reduces energy consumption andair pollution.

Recycling Benefits, Incentives

• Recycling saves money, energy,raw materials, and land space,while also reducing pollution.

• Recycling encourages individualawareness and responsibility.

• Japan - probably the mostsuccessful recycling program in theworld

• Creating incentives for recycling -public policies, consumer demand

• Some make a living by gatheringup recyclables!!

PhytostabilizationPlants such as willowtrees and poplars canabsorb chemicals andkeep them fromreaching groundwateror nearby surfacewater.

RhizofiltrationRoots of plants such assunflowers with danglingroots on ponds or in green-houses can absorb pollutantssuch as radioactive strontium-90 and cesium-137 and variousorganic chemicals.

PhytoextractionRoots of plants such as Indianmustard and brake ferns canabsorb toxic metals such aslead, arsenic, and others andstore them in their leaves.Plants can then be recycledor harvested and incinerated.

PhytodegradationPlants such as poplarscan absorb toxic organicchemicals and breakthem down into lessharmful compoundswhich they store orrelease slowly into the air.

Inorganicmetal contaminants

Organiccontaminants

Radioactivecontaminants

Brake fernPoplar treeIndian mustardWillow treeSunflower

Oilspill

Landfill

GroundwaterSoil

PollutedleachateDecontaminated

water out

Pollutedgroundwaterin

GroundwaterSoil

MAIN ISSUES

• ABSENCE OF SEGREGATION OF WASTE AT SOURCE

• LACK OF TECHNICAL EXPERTISE ANDAPPROPRIATE INSTITUTIONAL ARRANGEMENT

• UNWILLINGNESS TO INTRODUCE PROPERCOLLECTION, SEGREGATION, TRANSPORTATIONAND TREATMENT / DISPOSAL SYSTEMS

• INDIFFERENT ATTITUDE OF CITIZENS TOWARDSWASTE MANAGEMENT DUE TO LACK OF AWARENESS

• LACK OF COMMUNITY PARTICIPATION TOWARDSWASTE MANAGEMENT AND HYGIENIC CONDITIONS