Environmental pollution

Environmental pollution
In this topic we are going to deal about different types of pollution and due to these types of pollution how our environment is facing disasters and calamities.
Introduction:
Environmental pollution can be defined as “the unfavorable alteration of our surroundings”
Types of pollutants:
1. Bio degradable pollutants - decompose rapidly by natural processes.
2. Non-degradable pollutants-do not decompose or slowly decompose in the environment.
Pollutions are different kinds
1. Air pollution
2. Water pollution
3. Soil pollution
4. Marine pollution
5. Noise pollution
6.Thermal pollution and
7. Nuclear hazards
I-Air pollution:
It may be defined as “the presence of one or more contaminants like dust, smoke, mist and odour in the atmosphere which are injurious to human beings, plants and animals
Sources of air pollution:
a)Naturalpollution -volcanic eruptions, forest fires, biological decay, etc.
b)Man – made activities – Thermal power plants, agricultural activities etc.
Control Measures:
1. Source control:
a)Use only unleaded petrol
b)Use petroleum products and other fuels that have low sulphur and ash content
c)Plant trees along busy streets because they remove particulates and carbon monoxide and absorb noise.
d)Industries and waste disposal sites should be situated outside the city centre.
e)Use catalytic converters to help control the emissions of carbon monoxide and hydrocarbons. 2.Control measures in Industrial centers :
a)Emission rates should be restricted to permissible levels
b)Incorporation of air pollution control equipments in the design of the plant lay out.
II-Water pollution:
It may be defined as “the alteration in physical, chemical and biological characteristics of water which may cause harmful effects on human and aquatic life”.
Types, effects and sources of water pollution:
1.Infectious agents: - Bacteria, viruses, protozoa and parasitic worms.
Sources: - Human and animal wastes.
Effects: Variety of diseases.
2.Oxygen demanding wastes: - Animal manure and plant debris that can be decomposed by aerobic bacteria. Sources: - Sewage, paper mills, and food processing facilities
Effects: Wastes can degrade quality by depleting water of dissolved oxygen.
3. In organic Chemicals: - Water soluble inorganic chemicals.
1. Acids
2. Compounds of toxic metals such as lead , arsenic and selenium
Effects: Genetic mutations, birth defects and certain cancers.
Control measures of water pollution:
1. The administration of water pollution should be in the hands of state orcentral government.
2. Industrial plants should be based on recycling operations, because it will not only stop the discharge of industrial wastes into natural water sources but by products can be extracted from the wastes.
3. Plants, trees and forests control pollution and they acts as natural air conditioners.
4. Highly qualified and experienced persons should be consulted from time to time for effective control of water pollution.
5. Basic and applied research in pubic health engineering should be encouraged.
III - Soil Pollution:
It may be defined as “the contamination of soil by human and natural activities which may cause harmful effects on living beings”.
Types:
1. Industrial wastes
Sources and effects: - pulp and paper mills, chemical industries, oil refineries, sugar factories etc., these pollutants affect and alter the chemical and biological properties of soil. As a result, hazardous chemicals can enter into human food chain from the soil; disturb the bio chemical process and finally lead to serious effects.
2. Urban wastes
Sources and effects: - Plastics, Glasses, metallic cans, fibers, papers , rubbers , street sweepings, and other discarded manufactured products. These are also dangerous.
3. Agricultural practices
Sources and effects: - Huge quantities of fertilizers, pesticides, herbicides are added to increase the crop yield. Apart from these farm wastes, manure, slurry, are reported to cause soil pollution.
4. Radioactive pollutants
Sources and effects: These are resulting from explosions of nuclear dust and radio active wastes penetrate the soil and accumulate there by creating land pollution.
5. Biological agents.
Sources and effects: Soil gets large quantities of human, animal and birds excreta which constitute the major source of land pollution by biological agents.
Control measures of soil pollution
1.forestry an d farm practices
2.Proper dumping of unwanted materials
3.Production of natural fertilizers
4.Proper Hygienic condition
5. Public awareness
6.Recycling and Reuse of wastes
7.Ban on Toxic chemicals.
IV-Marine pollution:
It may be defined as “the discharge of waste substances into the sea resulting in harm to living resources hazards to human health, hindrance to fishery and impairment of quality for use of sea water”.
Source of marine pollution:
The coastal zones contain rich heritage, coral reefs, wetlands, and sea grass beds.
Effects of marine pollutants:
1.The presence of heavy metals and organic pollutants cause more damage in birds as thinning of eggshell and tissue damage of egg.
2.Oil spilling causes abnormally low body temperature in birds resulting in hypothermia. 3.Oil films are able to retard significantly the rate of oxygen uptake by water.
Control measures of marine pollution
1.Plants for conserving marine biodiversity must be taken into account of human needs.
2.People should be educated about marine ecosystems and the benefits offered by them.
3.Local communities must be involved in protecting and managing their coastal resources
4.Social and economic incentives must be offered for conserving and sustainable use of marine resources. 5.Governments must manage their own water while extending cooperation to the neighboring states. V-Noise pollution:
It may be defined as “the unwanted, unpleasant or disagreeable sound that causes discomfort for all living beings”
Types of noise:
1. Industrial noise
2. Transport noise
3. Neighborhood noise
Effects of Noise pollution
1.This affects human health, comfort and efficiency.
2.It causes muscles to contract leading to nervous breakdown, tension
3.It affects health efficiency and behavior.
4.In addition to serious loss of hearing due to excessive noise, impulsive noise also causes psychological and pathological disorders.
5.Brain is also adversely affected by loud and sudden noise as that of jet and aero plane noise etc.
Control and preventing measures
1.Source control – acoustic treatment to machine surface , designchanges , limiting the operational timings 2.Transmission path intervention- the source inside a sound insulating enclosure, construction of a noise barrier or provision of sound absorbing materials
3.Oiling – Proper oiling will reduce the noise from the machines.
VI-Thermal pollution:
It may be defined as the “addition of excess of undesirable heat to water that makes it harmful to man, animal or aquatic life or otherwise cause’s significant departures from the normal activities of aquatic communities in water”
Sources of thermal pollution
1.Nuclear power plants
2.Coal fired power plants
3. Industrial effluents
4. Domestic sewage
5.Hydro – electric power.
Effects of thermal pollution
a)Reduction in dissolved oxygen
b)Increase in Toxicity
c)Interference with biological activities
d)Interference with reproduction
e) Direct mortality
f)Food storage for fish
Control measures of thermal pollution:
a)Cooling towers: - This is used as a coolant, i.e., wet cooling tower, Dry cooling tower
b) Cooling ponds
c) Spray ponds
d)Artificial lakes – The heated effluents can be discharged into the lake at one end and the water for cooling purposes from the other end.
VII-Nuclear Hazards:
The radiation hazard in the environment comes from ultraviolet, visible, cosmic rays and micro wave radiation which produces genetic mutation in man.
Sources of Nuclear Hazards:
1.NaturalSources – which is in space which emitcosmic rays
2.Man made sources ( Anthropogenic sources) These are nuclear power plants, X-rays , nuclear accidents, nuclear bombs, diagnostic kits etc
Effects of Nuclear Hazards
1.Exposure of the brain and central nervous system ot high doses of radiation causes delirium, convulsions and death within hours or days.
2.The use of eye is vulnerable to radiation. As its cell die, they become opaque forming cataracts that impair sight.
3.Acute radiation sickness ios marked by vomiting , bleeding of gums and in severe casesmouth ulcers.
4.Nausea and vomiting often begin a few hours after the gastrointestinal tract is exposed . Infection of the intestinal wall can kill weeks afterwards.
5.Unborn children are vulnerable to brain damage or mental retardation , especially if irradiationoccurs during formation of the central nervous system in early pregnancy.
Control measures:
1.Nuclear devices should never be exploded in air.
2.In nuclear reactors, closed cycle coolant system with gaseous coolant may be used to prevent extraneous activation products.
3.Containments may also be employed to decrease the radio active emissions.
4.Extreme care should be exercis3ed in the disposal of industrial wastes contaminated with radio nuclides.
5.Use of high chimneys and ventilations at the working place where radioactive contamination is high. It seems to be an effective way for dispersing pollutants.
Solid Waste Management:
Management of solid waste is very important in order to minimize the adverse effects of solid wastes.
Types of solid wastes:
1. Urban wastes
Sources – a) Domestic wastes – Food waste, Cloth, Waste paper etc
B)Commercial wastes – Packing material, cans, bottles , polythene etc.
C)Construction Wastes – Wood, concrete debris etc.
D)Bio medical wastes – Anatomical wastes , infectious wastes etc.,
2. Industrial wastes
Sources – a) nuclear power plants – generates radioactive wastes
B Thermal power plants – produces fly ash in large quantities
3. Chemical industries
Produces large quantities of hazardous and toxic materials
Steps involved in solid waste management:
1.Reduce, Reuse and Recycle of materials – raw materials re usage should be reduced , reuse of waste materials should be reduced and recycling of the discarded materials into new useful productsshould also be reduced.
2. Discarding wastes
a)Land fill : Solid wastes are placed in sanitary landfill system in alternate layers of 80 cm thick refuse, covered with selected earth fill of 20cm thickness
b)Incineration: It is a hygienic way of disposing the solid waste. It is a thermal process and is very effective for detoxification of all combustible pathogens
c)Composting: It is another popular method practiced in many cities in our country. Inthis method , bulk organic waste is converted into a fertilizing manure by biological action.
Role of an individual in prevention of pollution:
1.Plant more trees
2.Help more in pollution prevention than pollution control
3.Use water, energy and other resources efficiently
4.Purchase recyclable, recycled and environmentally safe products
5. reduce deforestation
6.Remove NO from motor vehicular exhaust
7.Use of eco friendly products.