Pollution &its Hazardous Effects

Pollution: Pollution is also called environmental pollution. The addition to the environment of any substance or energy form e.g. heat at rate faster than the environment can accommodate by depression, breakdown, recycling, and storage in some harmless form. Pollution of the natural environment is largely unintended and unwanted consequences of human activities in manufacturing, transportation, agriculture and waste disposable. High levels of pollution are largely a consequence of industrialization, urbanization and the rapid increase of human population in modern times. Pollutants commonly are classified according to the part of the environment primarily effected by them either by air, water or land. Sub grouping depends on characteristics of the pollutants themselves: chemical, physical, thermal and others. Many pollutants affect more than one resource. The substances that pollute the atmosphere are either gases, finely divided solids, or finely dispersed liquids aerosols. Five major classes of pollutants are discharged into the air. Carbon Monoxide, Sulphur Oxides, Hydrocarbons, Nitrogen Oxides and particulates (dust, ash). The principal source of air pollution is the burning of fossil fuels e.g. coal, oil and derivatives of the latter, such as gasoline-in internal combustion, engines or for heating or industrial purposes.

Water Pollution: Nature has taken hundreds and thousands of years to shape this world up. And we, the human beings, are determined to destroy the earth at the earliest. Water is being contaminated and polluted like anything. Geographically, 70 % of earth is made up of water and the rest is made up of land. But as a matter of fact, human beings are bringing the entire 70 % of water under peril and intoxicating it through a careless

attitude to the environment. Industrial effluents, sewage and farm wastes are the major pollutants threatening the sanctity of our water resources. The organic and inorganic contaminants are acids, alkalis, carbohydrates, dyes, fats, soaps, waxes, gases, suspended matter, oil, toxic metals and pesticides including radioactive materials and heated effluents that impose thermal load on receiving waters. Biological pollutants include bacteria, viruses, plants and animals. “You can live without oil and you can even live without love, but you cannot live without water.” These are the words of Daniel Moynihan, former US Ambassador to India, underlining the seriousness of the water crisis in US but are relevant for the entire world. Water is the basic ingredient in the entire life cycle. The living cell is mostly water. Blood and sap are about 90 per cent water. The composition of blood and seawater is very similar, which lends support to the theory that life was created in the ocean waters. An adult’s body is about 65 per cent water. A loss of 15 per cent to this liquid proves usually fatal through dehydration. Humans require 2 to 3 liters of water a day just to maintain the racial liquid balance within the body. More than 4 liters may be required when the person is active. Not all this need be taken directly because our food intake also contains some water. Tomatoes contain 90 per cent water, potatoes 80 per cent and meat about 60 per cent. It is estimated that an average person eats about 50 tons of food and drinks about 40,000 liters of water in a lifetime. This is subject to variations from country to country. Enormous quantities of pure water are the basic requirement for every product we make. To refine a ton of sugar, 4,000 liters of really pure water are required. A ton of paper needs 300,000 liters of moderately pure water while for generating one kilowatt of electricity in a thermal plant about 3,500 liters are needed. A ton of steel needs 240,000 liters of water. Agriculture demands supply of water that far exceeds industrial needs. Actually water used in agriculture cannot be recirculated as is often possible in industry.

For growing a ton of cotton 8 million liters of water are needed while a ton of sugar crop consumes nearly a million liters of water. Water pollution includes the accumulation in oceans, lakes, streams, and ground water of substances that are either directly harmful to life or that have harmful secondary or long term effects. The principle sources of water pollution are sewage, industrial waste, garbage and refuse, and agriculture fertilizers, pesticides and herbicides. Any body of water has a capacity to absorb or break down introduce materials and sewage and some organic industrial waste `are broken down naturally by microorganisms into forms in which they are useful to aquatic life. But if the capacity of a body of water to dissolve, disperse or recycle is exceeded, all additional substances become polluted.

Types of water pollution: Oil Pollution: Oil pollution is one of the highest publicized forms of Ocean Pollution. The majority of oil pollution is from spills or leakages of oil that originate from land or rivers, which in turn flow to the sea. The more direct form of oil pollution occurs when ships transporting the substance leak or crash. Some of the oil washes up on the shore and becomes tar-like lumps; some coat the fur of animals (e.g. sea otters) affecting their natural heating system. Also, some oil finds its way to other water sources (such as lakes, rivers, and personal water supplies) causing hazardous water to be consumed. In extreme cases, rivers, lakes and wells have been known to ignite. For example, in 1969, the Cuyahoga River in Cleveland, Ohio ignited. Toxic Wastes: Toxic waste is the most harmful form of pollution to marine creatures and humans alike. Once a form of toxic waste affects an organism, it (the toxic waste) can be quickly passed along the food chain and might eventually end up as seafood, causing various problems. Toxic wastes arrive

from the leakage of landfills, dumps, mines and farms. Sewage and industrial wastes introduce chemical pollutants such as PCB, DDT, and Sevin. Farm chemicals (insecticides and herbicides) along with heavy metals (e.g., mercury and zinc) can have a disastrous affect on marine life and humans alike. Radioactive wastes, reactor leaks, natural radioactivity, and radioactive particles, which originate from the Atmospheric Testing Program from explosions of nuclear weapons, are dispersed in water all over the world. The effect of these radioactive particles is currently being researched. All of these factors allow seafood to have a chance of being hazardous to human health. For example, if a fish is contaminated with the metal Mercury (by either eating it or consuming a creature who had), birth defects and nervous system damage in humans may result. Also, Dioxin causes genetic and chromosomal mutations in marine life and is suspected of causing cancer in humans. Medical wastes, such as stale blood vials, hypodermic needles, and urine samples that have been found in ocean around the U.S. are being researched to determine if swimmers have a chance of contracting Hepatitis or AIDs from such wastes. Other wastes have been known to cause viral and bacterial diseases such as cholera, typhoid, dysentery, and diarrhea. Ocean Dumping: The lawful ocean dumping of various pollutants was once common practice, but is now regulated. However, the wastes that were dumped into the ocean in the early 1900's remain there still. Human wastes, ground-up garbage, water from bathing, and plastics all contribute to ocean dumping. Examples of trash found in the ocean are: syringes, laboratory rats, human stomach lining, Navy decontamination kits, test tubes with various substances (with radioactive markings), tampon applicators, and a walletsized photo of a dead communist dictator.

One of the main causes of trash finding its way to the ocean is the fact that some sewage pipes share their space with storm water drains. Rainfall (at least 1/4 of an inch), causes the sewage pipes to flood and the sewage wastes (basically anything you flush down your toilet), mingles with the storm water drain which flows unhindered to a water source. Balloons have been known to find their way into animals such as sperm whales, blocking their digestive tracts; causing the animals to die. Plastic sixpack rings choke various animals and animals for food mistake other waste. Basically any unnatural trash can be harmful to ocean life.

Noise Pollution: The word noise, which is derived from the Latin word ‘nausea’, has been defined in different ways. In law, noise may be defined as ‘an excessive, offensive, persistent or starling sound. In short, the best definition of noise is ‘sound which is undesirable by the recipient’. This subjective definition of noise differs from the scientific definition of noise. Noise is one of the undesirable products of technological civilization. Admits this civilization, wherever we go, noise surrounds us. The roar of traffic, the passage of trains and aeroplanes, the bustle our ears. Even home is invaded by noise. The noise from whatever source it comes from is undoubtedly, physiologically as well as psychologically harmful, it is ‘an invisible but insidious form of pollution. Noise as a potentially harmful pollutant is being recognized as a great nuisance these days affecting the quality of life, particularly, in urban areas. As cities grow and there are more motor vehicles, air traffic, factories and people, the level of noise grows accordingly. Noise is often defined as unwanted sound. Noise problems are becoming increasingly severe, especially in urban areas. Noise has come to be regarded as a major urban pollutant capable of causing annoyance and hearing loss and perhaps even adverse physiological and psychological effects. According to its magnitude,

its continuity and varying susceptibility of different individuals, noise can induce temporary or permanent impairment of hearing.

Sources of noise pollution: Noise pollution has been strengthening its grip on the society since last two decades. Damages caused by other problems are reversible to some extent whereas in case of noise pollution, it’s irreversible. The major sources of noise pollution are: •

Loud speakers

•

Automobiles

•

Aircrafts

•

Trains

• Construction works •

Projection of satellites into space

•

Industry & Machinery.

•

Entertainment

Effects of noise pollution: The effects of noise pollution are multifaceted and interrelated. Noise pollution has ill effects not only on the human beings but also on other living and non- living things. A few common effects may be discussed as following: Noise Effects on Human Beings

Noise Hazards

Noise Nuisance

Permanent hearing loss Neurol-humoral stress response Destruction of artifacts

Efficiency Mental stress Frustration Task interference Irritability

Comfort Sleep interference Communication Invasion of Privacy Damage of artifacts

Enjoyment Concentration Interference Meditation Recreational Hearing Loss

Effects of High Intensity Noise on Human Beings Noise dB

Effects Observed 0

Threshold

of audibility 150

Significant Change in pulse rate

110

Stimulation of reception in skin

120

Pain threshold

130-135

Nausea, vomiting dizziness, interference –with touch and muscle sense

140

Pain in ear, prolonged exposure caused

insanity 160

Minor permanent damage if prolonged

190

Major permanent damage in short time

Soil Pollution: Land- an inelastic resource is the most important natural resources of any region which not only provide the basis for economic activities but is the main factor for the very existence and development of the community. Required for agriculture afforestation, housing, industry, commerce and many other purposes, this resource following burgeoning population, rapid industrialization, urbanization and other human activities, has come under a tremendous pressure. The process of modernization and imprudent land use is causing degradation and pollution of this resource. The term “soil pollution” does not have a very precise meaning. This is because there are different types and degrees of pollution and the people have varying standards by which the judge pollution effects. Soil pollution

mainly involves the deposition on land of solid wastes such as cans, bottles, plastic containers, paper, and used cars that cannot be broken down quickly or, in some cases, at all. Aside from recycling, disposal methods include concentrating such materials in landfills, burning them in incinerators, or dumping them in ocean. The term land pollution also includes the accumulation on land of toxic chemicals (in solid or liquid form) produced by industry and of radioactive wastes from nuclear processing facilities. Massive mountains of solid wastes are disposed each day by our consumer society. It is estimated that about 10 billion tones of solid wastes are produced every year in the world and are dumped into the surroundings. Solid wastes are an integral part of our life as they devour our precious landscape spoiling the aesthetics of the surroundings. Solid wastes are unwanted materials thrown away in solid form, arising from the normal community activity. It includes garbage i.e. kitchen and food wastes, rubbish materials like paper, rag, glass bottles, metallic cans, plastics, fibers, residues from home fuels, street sweeping, building debris, rubbles and abandoned vehicles.

Sources of soil Pollution: Sources of Land pollution are many. Land or the soil pollution stems principally from the following: •

Indiscriminate disposal of solid wastes

•

Mining or ore processing etc. •

Contamination of soil with man-made chemicals, and

•

Improper land use and planning.

Effects of soil Pollution: The effects of land pollution are numerous, interrelated and of adverse consequences on the entire ecological system. Land pollution caused by

indiscriminate disposal of solid and semi-solid wastes, particularly in the urban areas besides presenting unsightly scene, poses a grave threat to human health. Huge piles of garbage at the disposal sites and littered around in the towns remains a dwelling place for flies, bacteria, mosquitoes and other harmful insects. The atmosphere in the vicinity of disposal sites of wastes is affected by the obnoxious smells and pathogens emitted or produced in the process of decomposition of garbage which eventually is a cause of intestinal and respiratory diseases in human beings. Presence of explosives, highly toxic substances, plastic and diseased culture etc. In the solid wastes put the health and safety of sanitary workers at risk which may ensure from occupational diseases, contact with the toxic materials in the course of collection, transportation and disposal of solid waste. The adverse economic effects of solid wastes, too, are far reaching. The squandering of limited and non-renewable mineral resources such as copper, zinc, lead and tin etc. disposed of and indiscriminately dumped in solid wastes- beyond recovery inevitably produce a disruptive economic impact.

Air pollution: A man can live without food for a month, without water for two or three days, but he cannot live without breathing even for a minute. According to research, it is estimated that an average adult male breathes in 15 kg of air a day, in comparison to about 1.5 kg of the food consumed and 2.5 kg of water intake. Hence it is obvious that the quantum of pollutants that enter our body through respiration would be manifold in comparison to those taken in through polluted water or contaminated food.

Air is a mixture of gases comprising 78 per cent nitrogen, 21 per cent oxygen and a little less than 1 per cent argon, together with 0.03 per cent carbon dioxide. These elements make upto 99.9 per cent of dry air. As long as this composition is maintained, the air is pure. If this composition is altered, i.e. the oxygen level gets reduces or other harmful gases enter the

atmosphere, then the air is said to be polluted and inhalation of this polluted air can lead to respiratory disorders

The atmosphere the earth envelope is a mixture of various gases, with a total mass of about 5.1 x (10)15 tones about 0.00001percent off the planers mass. The composition of the atmosphere has been stable over the period human life has been in existence, which indicates that it is suited to us. The composition of the unpolluted air is given in table: Constituent Nitrogen

Volume per cent 78.09

Oxygen

20.94

Argon

0.93

Carbon dioxide

0.03

Balance @

0.01

About 99.99 % of the mass of the atmosphere is concentrated within a height of about 80 kilometer of the earth’s surface. This is one of the factors that make our planet hospitable of life through some basic functions. The atmosphere shields and protects us from harmful things like ultra violet radiation from space and extraterrestrial bodies like comets and asteroids reaching and hitting the Earths surface. It functions as a medium of storage and distribution for much substance that is integral parts of vital life processes that take place continuously on the Earth. For example, it stores and distributes water vapor and heat energy to make our climate moderate. It stores and distributes oxygen, carbon dioxide and nitrogen, which are integral constituents of all life forms. An important function of, the atmosphere, which is of interest in air pollution is that, it stirs, dilutes and distributes the various pollutants that we put into it. The behavior of the atmosphere is the major factor, which completely determines whether, our pollution, haunts us or will blow away to trouble someone else.

Air pollution is a particular problem in urban areas, where the ultra violet rays in sunlight combine with hydrocarbon and nitrogen oxide to form photochemical smog. On a somewhat wider scale, So2 a nitrogen oxide from the burning fossil fuel can combine with atmospheric water vapor to form acid rain which is damaging to water, forest and soil resources. As a result of the increased consumption of fossil fuel, levels of carbon dioxide in the atmosphere have risen steadily in the 20th century and show signs of increasing atmospheric temperature worldwide owing to the greenhouse effect.

Types of Air Pollution: Air pollution is indication of disturbances to the composition of compounds in the atmosphere, as it may be summarized as shown: •

Excess emission of gases/vapors into atmosphere

•

Saturation of chemical compounds/particulates

•

Rate of dissipation < (smaller than) rate of absorption through various cycles (i.e. carbon and nitrogen cycle)

•

Emergence

of

new

chemical

reactions

of

reactive

and

non-

biodegradable compounds. Following are some of his common pollutants occurring in the air:

1. Gases Pollutants: Sources: The sources of gaseous pollutants are the vehicles, industries, manufacturing processes and even agricultural activities. Combustion of fossil fuels release oxides of Sulphur and nitrogen. SO2 is released even from petroleum refineries and nitrogen oxides are produced from the power generators carbon monoxide is another harmful gas released during combustion. Agricultural activities are responsible for air pollution, to some extent. Because of spraying and dusting, organic phosphates and chlorinated hydrocarbons are added.

Ammonia produced from fertilizer factories and

from cold storage systems is added to the air.

Particulate pollutants:

The particulate pollutants include dust from

crushing and grinding due to road mix plants and the construction work. Silica particles and asbestos particles, fibers from textile mill are other particulate pollutants, particulate fluorides; lead particles are still other pollutants of this class.

Pollen grains and the spores when produced in

excess also act as natural pollutants. Smog: The mixture of smoke and fog together produced smog (‘smo’ from smoke and ‘g’ from fog). It is actually fog carrying carbon particles. Smog is the result of heavy traffic on the highways. Photochemical oxidants: These pollutants are the secondary pollutants. NO2 and hydrocarbons react with each other in presence of light. The major oxidants are ozone and peroxyacetyl nitrate [PAN].

2. Radioactive pollutants: Nuclear activities are responsible for addition of the new type of pollutants to the air.

Nuclear fission from nuclear reactors and testing for nuclear

weapons are other sources of such pollution. many years.

These pollutants persist for

After effects of atomic blast of 1945, are still observed in

Japan. The atomic reactor at Chernobyl in former USSR blew off and a thick cloud of radioactive substances decipated in the atmosphere. Radioactive pollutants are the most dangerous, because they affect the chromosomes and bring about hereditary disorders.

Sources and Methods of air pollution: We can classify major sources that lead to air pollution to the following categories: •

Motor vehicle exhaust

•

Heat and power generation facilities

•

Industrial processes

•

Auto manufacturing

•

Fertilizers plants

•

Building demolition

•

Solid waste disposal

•

Solvent evaporation

•

Volcanic eruption

•

Fuel production

•

Roadway construction

•

Electrical components manufacturing

•

Extraction of metals

•

Forest fires

•

Agriculture

Source Fossil fuel Combustion Transportatio n Incineration Metallurgical Operations Chemical Industries

Smoke X

PartiSox culates X X

NOx X

X

X

X

X -----

X --X

--X X

CO X

Hydro- Toxic carbons Metals X X

Others ---

X

X

X

X

---

--X X

--X ---

-------

--X X

Odours Fluorides Ordours, fluorides, hydrogen sulphides,

Sewage

---

---

---

---

---

---

---

Field burning Mining

X ---

X X

X ---

-----

-----

-----

--X

Major pollutants

organic vapours Odours, hydrogen sulphides -----

Methods of pollution •

Combustion of fuel led to the production of oxides of lead, nitrogen and sulfur

•

Particulates release will cause haze and smog resulting in the

Motor vehicle exhaust

poor vision in the area •

Oxides of lead, nitrogen and

sulfur dissolves in water vapor and altering its pH and causing it more acidic •

Emission

of

excess

heat

to

atmosphere causing warming of the atmosphere •

Heat

and

power

Waste

biomass

not

incinerated,

generation

combustion

facilities

properly

incomplete and

unrecycled

remaining waste leads to the release

of

carbon

monoxide

(CO), and methane (CH4 ]

Industrial processes

•

Production of thick black smoke emitted without a proper filtering system lead to an increase of carbon dioxide emission

•

Emission

of

CFCs

(chlorofluorocarbon)

in

atmosphere will through a free radical

reaction

altering

the

structure of the ozone molecule (O3) by breaking the bond to produce free radicals. CFCs can be found in refrigerant products like refrigerator, aerosol spray •

Production of nitric acid ( HNO3 ) through Oswald process involves a series of combustion

•

Emits

about

1180

tons

of

organics; 54 tons of NOx (oxides of nitrogen); 730 pounds of SO2; and 7 tons of carbon monoxide (CO)

Auto Manufacturing •

Increase production of vehicles has led to the increase of usage organic

products,

and

heavy

metals Fertilizers Plants

•

Emission of corrosive byproducts like sulphuric acid (H2SO4) by Contact process and hydrochloric acid (HCl), which increase the acidity of water vapor in the atmosphere

•

Over

production

of

ammonia

(NH3) for fertilizer production,

which are not contained in a proper

manner

may

increase

alkalinity of atmosphere

•

Crumbling

rubble

and

debris

which floats and settles in the atmosphere, causing haze and smog (i.e. benzene, asbestos, Building demolition

beryllium, inorganic arsenic)

•

Accumulation of waste leads to production of strong odor and humidity,

right

conditions

for

pests (houseflies) and bacteria growths Solid waste disposal

which

further

aggravates the odor in the area •

Radioactive

and

hazardous

waste not disposed in enclose area will cause the release of radioactive vapors or substances into atmosphere Solvent evaporation

•

Vaporization of complex organic solvents

which

biodegradable methane ethane,

are

(i.e.

organic ethylene,

non

non -

compounds: aldehydes,

ketones) •

Production of strong unpleasant

odor (i.e. lubricants, paints) •

Organic

vapors

reacting

with

chemical

compounds

in

atmosphere

which

as

insulator producing

acts

earth,

thereby

greenhouse

effects

(i.e. methane, carbon dioxide)

•

Toxic and poisonous gases of SO2 , NO2 and PbS2 spewed out

Volcanic eruption

•

Heat produce during eruptions will increase the temperature of atmosphere, altering the rate of chemical reactions occurring

Fuel production

•

Fractional distillation of crude oil to produce kerosene, gasoline and refinery gas by the cracking process (pyrolisis) involves the use of high heat energy at 450°C splitting larger alkane molecules into smaller alkane and alkene molecules which are more easily vaporized

and

are

therefore

more useful fuels •

Fuel

extraction,

processing,

refining and distribution add an additional 14% of carbon dioxide emissions (CO2) •

30% of hydrocarbon emissions are

released

through

evaporation, which occurs from both fuel tanks and gasoline tanks

•

Manufacture

of

construction

equipment comparable to the degree

of

pollution

of

auto

which

are

manufacturing Roadway construction

•

Asphalt

fumes

bothersome involves

and

the

particulate

toxic,

release

benzene

which

of

both

(C6H6)

–

soluble organics and individual aromatic hydrocarbons •

Process

of

semiconductors

making involves

the

usage of hazardous heavy metal (i.e. arsenic and lead) Electrical manufacturing

components

•

Emission of toxic byproducts into river

and

sulphates,

atmosphere

(i.e.

nitrates

and

sulphides)

Extraction of metals Extractions of pure metal involves the heating of coke (carbon); (i.e. iron and silicon) produce carbon

dioxide and carbon monoxide •

Extractions of Group 1 and 2 metals

(sodium,

magnesium,

potassium,

calcium)

through

electrolysis involves the usage of graphite (carbon) and mercury as the electrode

•

Release

of

particulates

into

atmosphere causing smog and haze results in the poor vision of

Forest fires

sight in the area

•

Improper sanitation results in the accumulation of faces and urine

Agriculture

causing strong odor and smell contamination in the area

Air Pollution and Health Hazards: All the air pollutants severely affect the health of human beings. Some of the main air pollutants and their side effects on human health are given below the in the table: Pollutants Chloroform

Sources And Side Effects Sources: Disinfectors Side Effects:

Cancer Para-dichlorobenzene Sources: Air freshener, campers Side Effects:

Tetra chloroethyl

Cancer Sources: Vapour from cloth-dryer liquid that left in clothes Side Effects: Heart disorder, damages to kidney and herpes cancer.

Sources: Styrene

Carpets and plastic Side Effects:

Radon-222

Damages to kidney and herpes Sources:

Radioactive soil, foundation stone, water sources. Side Effects:

Smoke

Lung cancer form Sources:

Cigarette Cigarette Side Effects:

Carbon Monoxide

Lung and respiratory system cancer, heart damage Sources: Kerosene cooking stove board, damaged fire store in living room. Side Effects: Headache,

Nitrogen Oxide

improper

heartbeats,

excessive

sleepiness. Sources: Wood board Side Effects:

1,1,1-Trichloroethane

Lung irritation, fever to children, headache. Sources: Aerosol spray Side Effects: Headache and respiratory difficulties

Asbestos

Sources: Pipe isolation and tile. Side Effects: Lung damages and cancer

Air Quality Standards: Each country ha set its national air quality standards which much not be exceeded if public health and welfare are to be protected. The central Board for Prevention and Control of Pollution of India has prescribed the following air quality standards for some pollutants. Area Category

Suspended

Sulphur

Oxides of

Carbon

particulate

dioxide

nitrogen

monoxide

Industrial and mixed

matter 500

120

120

5000

use Residential and rural Sensitive (hill stations,

200 1

80 30

80 50

2000 1000

tourist resorts, national parks, monuments,

00

health resorts etc.) The values for Sulphur dioxide and oxides of nitrogen present annual averages when monitored uniformly over twelve months of the year, with a frequency of not less than once a week with a sampling time of 8 hours, The concentration of the pollutant shall be 95 per cent of the time within the prescribed limits. At present the monitoring programmers in India are not geared up for systematic work. These standards are invariably exceeded in many regions of the country, usually the densely populated urban industrial areas. Another important aspect is that the technology employed in most of the industrial units as well as automobiles is not updated with in-built pollution control devices. According to New York Times Magazine the air quality in big cities in India is among the worst in the world.

According to one report, Delhi, the Indian

Union Capital, has 1.3 million registered vehicles, 120,000 being added annually?

Two and Three wheelers constitute about 63 per cent. The

vehicular traffic contributes more then 800 Ions of pollutant gases every day, which constitutes more than 60 per cent of the air pollution in the city. During peak time the emissions are estimated at Carbon monoxide Hydrocarbons Oxides of nitrogen

1,500kg 500kg 1000kg

Over 400 kg of lead are released into the air every day. The two thermal power stations emit 1,450 tons of flyash and 600 tons of Sulphur dioxides every day. There are 5,000 noxious gas-emitting industries in the capital, 868 of which the walled city itself. As many as 28 large industries release chlorine and other dangerous substances. The water-polluting industries are put at 82.

Environmental Effects of Acid Rain

Do you think that she knows what acid rain is? Air Pollution Creates Acid Rain... Scientists have discovered that air pollution from the burning of fossil fuels is the major cause of acid rain. Acidic deposition, or acid rain as it is commonly known, occurs when emissions of Sulphur dioxide (so2) and oxides of nitrogen (nox) react in the atmosphere with water, oxygen, and oxidants to form various acidic compounds. This mixture forms a mild solution of sulfuric acid and nitric acid. Sunlight increases the rate of most of these reactions. These compounds then fall to the earth in either wet form (such as rain, snow, and fog or dry form (such as gas and particles). About half of the acidity in the atmosphere falls back to earth through dry deposition as gases and dry particles. The wind blows these acidic particles and gases onto buildings, cars, homes, and trees. In some instances these gases and particles can eat away the things on which they settle. Dry deposited gases and particles are sometimes washed from trees and other surfaces by rainstorms. When that happens, the runoff water adds those acids to the acid rain, making the combination more

acidic than the falling rain alone. The combination the acid rain plus dry deposited acid is called acid deposition. Prevailing winds transport the compounds, sometimes hundreds of miles, across state and national borders.

.

Wouldn't you rather see this...?

Electric utility plants account for about 70 percent of annual SO 2 emissions and 30 percent of NOx emissions in the United States. Mobile sources (transportation) also contribute significantly to NOx emissions. Overall, over 20 million tons of SO2 and NOx are emitted into the atmosphere each year. Acid rain causes acidification of lakes and streams and contributes to damage of trees at high elevations (for example, red spruce trees above 2,000 feet in elevation). In addition, acid rain accelerates the decay of building materials and paints, including irreplaceable buildings, statues, and sculptures that are part of our nation's cultural heritage. Prior to falling to the earth, SO2 and NOx gases and their particulate matter derivatives, sulfates and nitrates, contribute to visibility degradation and impact public health.

Implementation of the Acid Rain program under the 1990 Clean Air Act amendments wills confers significant benefits on the nation. By reducing SO2 and NOX, many acidified+ lakes and streams will improve substantially so that they can once again support fish life. Visibility will improve, allowing for increased enjoyment of scenic vistas across our country, particularly in national parks. Stress to our forests that populate the ridges of the mountains from Maine to

Georgia will be reduced.

Deterioration of

our historic buildings and monuments will be slowed. Finally, reductions in SO2 and NOx will reduce sulphates, nitrates, and ground level ozone (Smog), leading to improvements in public health. Control Measures: 1) Tall chimneys of factories help to discharge pollutants at the highest altitudes. 2) Automobiles should be checked regularly for their efficiency as regards complete combustion of fuels. 3) Green vegetation around the industry seems to be a good solution to reduce pollution.

Trees act as biomonitor for the problem of

pollution. 4) Setting chambers, bag filters, wet collectors; gas absorbers are some of the equipments useful in the control of air pollution. 5) If use of a row material produces more pollution, a suitable one should replace it. For example, the use of a fuel containing less percentage of Sulphur. 6) Modification in the equipment can pose less pollution problem. E.g. instead of using open hearth furnace, oxygen furnace is used to reduced pollution.

Cases Studies: Bhopal Tragedy:

On Dec 3, 1984 methyl isocyanate [MIC] accidentally

leaked out form the storage tanks of the insecticide and germicide factory at Bhopal. This MIC killed over 3000 and seriously affected nearly lakhs of the residents.