Pollutants

Responsible agents of pollution is called pollutants.

Pollutants

Primary pollutants: Chemicals or substances emitted directly into the air are primary pollutants.

Secondary pollutants: If these pollutants react with other substances in the air and form a new compound they are called secondary pollutants

Pollution is the release of environmental contaminants.

The U.S., Russia, Mexico, China and Japan are the world leaders in air pollution emissions;

Pollution

Types of pollution air pollution, the release of chemicals and particulates into

the atmosphere. Common examples include carbon monoxide, sulfur dioxide, chlorofluorocarbons (CFCs), and nitrogen oxides produced by industry and motor vehicles. Ozone and smog are created as nitrogen oxides and hydrocarbons react to sunlight.

water pollution via surface runoff and leaching to groundwater.

Soil contamination occurs when chemicals are released by spill or underground storage tank leakage. Among the most significant soil contaminants are hydrocarbons, heavy metals, MTBE, herbicides, pesticides and chlorinated hydrocarbons.

Types of pollution radioactive contamination, added in the wake of

20th-century discoveries in atomic physics. (See alpha emitters and actinides in the environment.)

noise pollution, which encompasses roadway noise, aircraft noise, industrial noise as well as high-intensity sonar.

light pollution, includes light trespass, over-illumination and astronomical interference.

visual pollution, which can refer to the presence of overhead power lines, motorway billboards, scarred landforms (as from strip mining), open storage of junk or municipal solid waste.

Air PollutionThe air pollution may be defined as qualitative

and quantitative changes in the atmospheric constituents due to addition or contamination of such substances as may be harmful to man and his environment.

Fresh air composition:N2 79%O2 20.94%CO2 0.032%Others 0.028%

Air pollution categoryAir pollution may be categorized in to indoor

and out door pollutions:

In door Pollution: Pollution of atmosphere inside building, offices and residences is called indoor air pollution. eg. CO2 from metabolic activities of living organisms, and combustion of fuels.

Out door pollution: Atmospheric pollution in the open space is referred to as outdoor air pollution. eg Lead from Automobiles and industrial emission, Ozone from photochemical reactions in atmosphere etc.

Cause of Air PollutionAtmospheric pollution is increasing due to the

following major factors:

Over population and increasing urbanization.

Increasing traffic

Industrialization and energy consumption

Over population and Urbanization:According to current estimates, the world population

is increasing at an average by two per cent annually which means the addition of about one million people every five days or five people every couple of seconds.

Increases in population would demand more food, water and land, the three items that are limited on the earth. This has resulted in disturbance in ecological balance, disruption of natural biogeochemical cycles and fast depletion of natural resources

Over population and Urbanization:Growing population created problems of

employment. This leads people to move from villages to urban areas in search of employment, comfort and facilities. As a result, the cities are expanding in area and are being thickly populated.

Thickly populated areas face a variety of problems such as congestion, large number of vehicles and its dust and smoke, accumulation of solid and liquid wastes, poor sanitation and management problems.

Increasing Traffic:Rapid increase in the number of automobiles in

one of the potential factors responsible for air pollution in urban areas. The vehicles on road are mobile sources of air pollution.

Combustion of fuel in aircraft engines produces hydrocarbons, nitrogen oxides, carbon monoxide, small amount of particulate matter, and sulphur oxides.

Amounts of pollutants depend upon the fuel used, type of aircraft engine etc.

Industrial Growth and Energy ConsumptionFossil fuel burning. eg. Burning of coal, oil,

gas in different industries .

Decomposition. eg. Natural decomposition, biogas plant, waste deposition of a city etc.

Industrial activities. eg. oil refineries, brick field,

stone crushing etc.

Industrial Growth and Energy ConsumptionIndustries are producing a variety of toxic

substances.

Brick field, stone crushing sector and oil refineries are releasing tremendous amount of fly ash and many toxic gases in to the atmosphere.

Domestic burning, agricultural refuse.

firewood and dry dung burning are also contributing considerable amounts of pollutants to atmosphere.

Effects of air pollutionHuman beings breathe 14 kg of air into their

lungs each day. Although some of the symptoms of pollution that people suffer involve the moist surfaces of the eyes, nose, and throat, the major site of impact is the lungs.

Effects of air pollutionThree categories of impact can be distinguished:

a) Chronic: Pollution cause the gradual deterioration of a variety of physiological functions over a period of years.

b) Acute: Pollutants bring on life-threatening reactions within a period of hours or days.

c) Carcinogenic: Pollutants initiate changes within cells that lead to uncontrolled growth and division (cancer).

Effects of air pollutionThere are lots of air pollutants caused different

physiological problem to the human beings, such as:

Long term exposure to sulphur dioxide, SO2 can lead to bronchitis.

Chronic inhalation of ozone and particulates can cause inflammation and ultimately fibrosis of the lungs.

Some of the air pollutant or sometimes smell of perfume may cause inflammation to the person those have Asthma.

Effects of air pollutionCarbon monoxide (CO) reduces the capacity

of the blood to carry oxygen, and extended low levels of carbon monoxide can contribute to heart disease.

Chronic exposure to nitrogen oxides (NO) is known to impair the immune system, leaving the lungs open to attack by bacteria and viruses (Pfafflin & Ziegler 1992, Miller 1997).

Effects of air pollutionAir pollution may also cause problem to the

atmosphere, such as Acid Rain.

Acid Rain: When the pH of rain water or snow is less than 5.7 it is called Acid rain. Acid rain is man-made ecological event. It is mainly due to sulfuric acid and nitric acid.

Effects of air pollution (Acid Rain)Formation of acid rain: Acid rain may form

from Sulfur mono or dioxide, Nitrogen dioxide etc. For an example: Action of sulfur dioxide leading to acid rain. It is formed in two steps:

Conversion of sulfur dioxide in to sulfur trioxide by absorption of UV radiation

Reaction of secondary pollutant sulfur trioxide with moisture to form sulphuric acid. Sulphuric acid dissolved in rain drops falls on the earth surface as acid rains.

2. Action of nitrogen dioxide leading acid rain: Nitrogen dioxide acts to produce acid rain in two steps:

Formation of nitrogen dioxide and nitrogen peroxide by absorption of UV radiation from the sun.

Reaction of nitrogen dioxide and nitrogen peroxide with atmospheric moisture to form nitric acid which falls down as acid rain.

Effects of acid rain:

Acid rain causes irritation in the eyes and skin of human beings.

It may cause corrosion of many buildings, bridges and monuments, railings, fencings etc.

It affects on the enzymatic activities of living being.

Acid rains change the pH of soils and affect the plant growth in various ways.

It inhibits carbon dioxide fixation and photorespiration and adversely affects the productivity of crops.

Acid rain and a Monument

The Taj Mahal of Agra is also facing danger from the acid rain because of oil refinery situated at Mathura very close to Agra. This refinery emits smoke and gaseous pollutants including sulfur dioxide. If the sulfur dioxide levels in air increases the resulting acidic precipitation may react with marbles and cause pitting in this wonderful monument that attracts people from all over the world.

Control of Air pollution

What can we DO ?

Control of Air pollution

1. Automobiles must be either made to eliminate use of gasoline and diesel oil or complete combustion is obtained in the engine so that noxious compounds are not emitted. The automobiles, trucks and other transport systems must have an antismog device to minimize pollution.

2. Aforestation, Reforestation

3. Excessive and undesirable burning of vegetation should be stopped.

Control of Air pollution

4. Smoking should be stopped (there is 5,00000 tones tobacco pollution annually).

5. Proper attention should be given by the government and general to make people realize the implications of environmental problem.

6. Legislation should be passed against pollution.

7. Environmental education is the best programme to deal with the environmental problems