POLLUTION-1.pptx Pollution of water, land and Air

Pollution

1. POLLUTION

2. DEFINITION OF POLLUTION Pollution is a process in which the quality of the environment is lowered when some materials known as pollutants are injected or released into the environment at concentrations above the accepted level.

3. DEFINITION OF POLLUTANT Pollutant is any substance introduced into any environment by man which causes the destruction or impairs the purity of the environment and causing harm to living organisms.

4. Pollutants that can be broken down by microorganisms are called BIODEGRADABLE pollutants while pollutants that can not be decomposed naturally by bacteria are called NON-BIODEGRADABLE pollutants. The most effective method of getting rid of them is by RECYCLING them e.g., plastics, metal scraps, glass, etc

5. EXAMPLES OF POLLUTANTS Heavy metals (such as mercury, zinc, nickel, lead), oil spillage from pipelines or tank, improper refuse disposal , untreated sewage , herbicides and pesticides , noise etc.,

6. MAJOR TYPES OF POLLUTION 1. Land pollution 2. Water pollution 3. Air pollution 4. Noise pollution

7. LAND POLLUTION

8. LAND POLLUTANTS SOURCES EFFECTS 1. Refuse Home, offices and industries It causes offensive odour when the refuse decay. 2. Sewage Homes and offices i. It can cause respiratory disoder ii. It results in offensive odour iii. It serves as a breeding ground for disease causing organisms.

9. 3. Metal scraps Abandoned vehicles and machines i. It occupy space ii. It prevents proper land use 4. Pesticides and Fertilizers Pesticides sprayed on crops and fertilizers used in soils i. They destroy useful soil organisms ii. Excess fertilizer can cause soil acidity iii. It can cause the death of aquatic organisms, e.g. fishes

10. 5. Chemicals, e.g. toxic wastes Chemicals waste from industries These are poisonous to plants and animals 6. Glass particles Glass manufacturing or industries using bottles i. It can cause injury to human skin or body . ii. It does not decay hence it prevents proper land use.

11. 7. Crude oil ( Oil spillage) Oil drilling, loading or unloading of oil tankers i. It destroys soil and renders it infertile ii. It destroys plants and animals’ life in water.

12. CONTROL OF LAND POLLUTION 1. Indiscriminate dumping of refuse should be discourage. 2. Refuse should be burnt in incinerators. 3. Urban wastes should be properly treated before disposal. 4. Sewage should be properly treated before disposal.

13. 5. Legislation should be made by government against dumping of harmful or toxic wastes. 6. Pesticides and fertilizers should be applied as instructed. 7. Metals scraps, tin cans, bottles, motor vehicle parts should be recycled. 8. Oil pipelines should be maintained and checked regularly to prevent sabotage or natural oil spillage.

14. AIR POLLUTION

15. AIR POLLUTANTS SOURCES OF POLLUTANTS HARMFUL EFFECTS 1. Carbon monoxide (CO): It is a colourless and odourless gas. It is produced by incomplete combustion of fuels like coal, diesel and petrol. It is emitted from motor vehicles, charcoal stoves, cigarette smoke and heaters. i. It affects the central nervous system (CNS). ii. Inhaling of CO in large quantities is fatal as it reduces the oxygen-carrying capacity of blood. It combines with haemoglobin and forms an irreversible compound called carboxyhaemoglobin . iii. It is poisonous and causes suffocation and in extreme cases leads to death.

16. 2. Hydrocarbons: Compounds of carbon and hydrogen, e.g. methane, benzene formaldehyde They are released from the exhausts of vehicles by incomplete burning of fuels. They are carcinogenic substances (substances that cause cancer)

17. 3. Sulphur oxides like sulphur dioxide (SO 2 ) Produced by burning of fossil fuels like petrol and coal . These are released in large amount by oil refineries and power plants i. Inhaling such air can cause respiratory problems and can lead to permanent lung damage ii. SO 2 and SO 3 react with water in the atmosphere and form dilute sulphurous and sulphuric acids iii. These acids combine with water vapours to form acid rain which is very harmful to plants, animals and buildings.

18. 4. Nitrogen oxides (NO 2 ) They are emitted from the automobiles. They are formed by combining N 2 and O 2 with coal and petroleum at high temperatus in the engines. i. They remain suspended in the air in the high traffic or congested areas and forms a reddish brown haze called brown air. ii. They are carcinogenic and causes lung problems and respiratory disorders iii. They form dilute solution of nitric acid in combining with water vapour and come down as acid rain.

19. 5. Particulate matter: Very small particles that remain suspended like soot, smoke, dust and asbestos etc. They are released by burning of fuels from vehicles, industries and burning of crops and agricultural stubble etc. They cause various respiratory disorders like asthma, chronic bronchitis etc.

20. 6. Smog (remains suspended in air during winter) It is produced by reaction of smoke from exhausts with fog or water vapour in air. i. It causes breathing or respiratory disorders. ii. It can lead to asthma, cough and lung disorders.

21. 7. Chlorofluorocarbons (CFC) CFCs damage the protective ozone layer. CFCs are used in refrigerators, air conditioners and aerosol sprays i. CFCs are responsible for creating a hole in the ozone layer, which is a protective layer around earth. ii. As more of UV rays reach the earth, it leads to increase in number of skin cancers

22. CONTROL OF AIR POLLUTION 1. Conditions must be created for complete combustion of fuel in internal combustion engines. 2. Chemical waste should be discharged into the air through fume chambers 3. Industries should be sited far away from residential areas.

23. 4. There should be provision of filters or absorbers to be worn around mining and industrial areas so as to reduce pollution from waste gases. 5. Legislation should be made against indiscriminate burning that may bring about smoke.

24. NOISE POLLUTION It is defined as unwanted high-pitched sound. It can be measured by a sound meter and is expressed in a unit called decibel (dB).

25. SOURCES OF NOISE POLLUTION 1. Electronic sound system 2. Car horn and Sirens 3. Generators 4. Airplanes 5. Factory /Industrial machines

26. 6. Canons shots/gun firing 7. Artillery firing 8. Quarry activity/ Construction site 9. Motor vehicles 10. High pitched loud speakers or drumming 11. Dynamic blastings, bulldozers, excavators, lawnmowers

27. EFFECTS OF NOISE POLLUTION 1. It causes loss of hearing or deafness 2. It can cause emotional disoder, anxiety or lack of concentration 3. It can also cause high blood pressure or hypertension. 4. It causes general irritation 5. It can also cause changes in behaviours

28. CONTROL OF NOISE POLLUTION 1. Legislation should be made against the use of loudspeakers in public places. 2. Education/public enlightenment 3. Siting factories, industries, railways and airports far away from residential areas. 4. Use of sound proof/silent generators. 5. Reduction of noise from loudspeakers and car sirens.

29. WATER POLLUTION This is the discharge into the water bodies any substance which may become harmful to living organisms in the water and make them unfit for human consumption.

30. POLLUTANTS OF WATER 1. Domestic waste/Sewage/Household waste 2. Industrial waste/dyes/detergents/lead/mercury compounds 3. Agricultural wastes/pesticides/insecticides/fertilizers. 4. Oil/oil spillage 5. Hot water/thermal plants

31. EFFECTS OF WATER POLLUTANTS ON AQUATIC ORGANISMS A. DOMESTIC WASTES i. Bacterial breakdown of sewage reduces dissolved oxygen in water/Eutrophication ii. Aquatic animals suffocate and die iii. Rapid growth of aquatic plants due to mineral rich sewage iv. Reduces light penetration and photosynthesis v. Contaminated sewage spread disease-causing organism

32. B. INDUSTRIAL WASTES i. They are poisonous to aquatic organisms ii. Detergents foam on the water surface tension causing floating animals animals to sink. iii. Phosphates cause rapid plant growth. iv. Dyes from textile factories reduce light penetration/photosynthesis

33. C. AGRICULTURAL WASTES i. These may accumulate to toxic levels thereby poisoning aquatic organisms. ii. Fertilizers residues stimulate growth of aquatic plants which form a dense mat on the surface of water leading to depletion of oxygen/eutrophication

34. D. OIL SPILLAGE i. Oil reduces surface tension of water causing floating animals to sink ii. Animals die due to lack of oxygen iii. Coats feathers/fur of animals making them unable to fly/causing affected animals to freeze/starve to death iv. Coats gills of aquatic organisms v. Reduces light penetration and decreases photosynthesis vi. Toxic to aquatic organisms

35. E. HOT WATER i. Kills living organisms ii. Upsets the balance of the ecosystem iii. Hot water increases the water temperature thereby reducing the oxygen content and leading to death.

36. CONTROL OF WATER POLLUTION 1. There should be an efficient and proper sewage disposal system 2. Dumping of refuse or petro-chemical by products into rivers, streams or seas should be avoided 3. There should be efficient techniques to deal with or prevent oil spillage 4. Industries should be sited far away from residential areas 5. Government or local authorities should striclty monitor all industrial wastes 6. There should be public enlightenment on waste disposal 7. Industrial effluents should be recycled.

37. EFFECTS OF POLLUTION ON AQUATIC ECOSYSTEMS Amount of dissolved oxygen (DO) in water is extremely important for the survival of aquatic ecosystems. The easiest way to establish the level of pollution in a local stream is to maesure the level of dissolved oxygen (DO).

38. NOTE: i. Normal value of DO in water bodies = 8.0 mg/litre. ii. Polluted water bodies have DO content < 8.0 mg/litre. iii. Heavily polluted water bodies have DO content < 4.0 mg/litre.

39. FACTORS THAT REDUCE DO CONTENT IN WATER 1. Biochemical Oxygen Demand (BOD). 2. Chemical Oxygen Demand (COD). 3. Temperature.

40. BIOCHEMICAL OXYGEN DEMAND (BOD) This is a measure of the amount of oxygen bacteria need to beak down the organic matter in a water sample in a fixed period of time. It enables us to test the degree of water pollution in ponds, lakes and rivers. Hence BOD is directly proportinal to input of oragnic wastes.

41. High input of organic wastes high BOD Higher BOD indicates a greater degree of water pollution. Higher amout of organic wastes cause a drop in DO content of water. Drinking water should have a low BOD.

42. CHEMICAL OXYGEN DEMAND Chemical Oxygen Demand is the measure of oxygen requirement for oxidation of total organic matter (biodegradable + non-biodegradable) present in water. High COD low DO.

43. EUTROPHICATION This refers to a condition caused by a sudden increase in the amounts of organic nutrients and minerals (nitrate and phosphate) in a lake or pond whereby there is an excessive growth of plant life/ algae/alga bloom leading to the death of aquatic organisms.

44. CAUSES OF EUTROPHICATION 1. Overuse of fertilizers 2. Sewage discharge 3. Wash from fish farming 4. Plant nutrients which drain off into water bodies