Environmental pollution: Causes & Control Measures

Types of Pollution, their effects and various control measures

1. Environmental Pollution- Causes, Effects and Control Measures By Spunky Padrone

2. Definit i on “Pollution is the effect of undesirable changes in our surroundings that have harmful effects on plants, animals and human beings”.

3. Pol l utant Any thing (solid, liquid or gas) that cause pollution is called pollutant Eg. Lead, sulphuric acid, carbon monoxide,

4. Types of Pollution Degradable Non-degradable Degradable: Those can be readily broken down by natural processes Eg. Discarded vegetables Non-degradable: Those can not be degraded by natural processes Eg.plastics

5. Types of Pollution Noise Air Water Land or Soil Thermal Nuclear

6. Air Pollution Air pollution occurs due to the presence of undesirable solid or gaseous particles in the air in quantities that are harmful to human health and environment

7. Types of pollutants Primary pollutants Pollutants that are emitted directly from identifiable sources – produced by both natural events or human activities Eg. Dust storms, emission from vehicles Secondary pollutants When certain chemical reactions take place among the primary pollutants Eg. Sulphuric acid

8. Primary pollutants Carbon oxides (CO2 and CO) Nitrogen oxides Sulphur oxides Volatile organic compounds – hydro carbons Suspended particulate matter

9. TERM MEANING EXAMPLES Aerosol Particles suspended on air Sprays from pressurized cans Mist Aerosol consisting of liquid droplets Sulfuric acid mist Dust Aerosol of solid particles that are blown into the air Dust storm Smoke Aerosol of solid and liquid particles produced by chemical reactions such as fires Cigarette smoke Fume Condensation of hot vapors of metals Zinc, lead fumes Plume Smoke coming out of chimney Fog Aerosol of water droplets Smog Mixture of smoke and fog

10. Sources of Air Pollution Vehicles Industries Dust and storm Air crafts, jet

11. Effects of air pollution Prolonged smoking or exposure to air pollutants can overload or break down the natural defenses such as hair in our nose, sticky mucas in the lining of the upper respiratory tract causing diseases like lung cancer, asthma, chronic bronchitis etc.,

12. Cigarette smoking is responsible for the greatest exposure to carbon monoxide.Exposure to air containing even 0.001% of carbon monoxide for several hours can cause collapse, coma and even death. CO is attached to blood hemoglobin for a long time, it accumulates and reduces the oxygen carrying capacity of blood. This impairs perception and thinking, slows reflexes and causes headaches, drowsiness, dizziness and nausea and blurred vision.

13. Nitrogen oxides and suspended particles both can irritate lungs, aggravate asthma or chronic bronchitis and increase respiratory infections. Many volatile organic compounds such as benzene and formaldehyde and toxic particulates such as lead and cadmium can cause mutations, reproductive problems and cancer, breathlessness and irritation of the eye, nose and throat.

14. Sulphur dioxide irritates respiratory tissues, chronic exposure causes a condition similar to bronchitis . It also reacts with water, oxygen and other materials to form sulphur containing acids – The acids can become attached to particles which when inhaled are very corrosive to the lung.

15. Chronic exposure of the leaves to air pollutants can break down the waxy coating that helps prevent excessive water loss and leads to damage from diseases, pests, drought and frost . It also affects photosynthesis, respiration and other metabolisms.

16. Ozone depletion The upper stratosphere consists of considerable amounts of ozone which works as an effective screen for UV light.

17. The ozone thus formed is constantly broken down by naturally occurring processes that maintain its balance in the ozone layer. But the presence of certain pollutants can accelerate the breakdown of ozone. (chloroflurocarbons, halons ) The Chloro-fluro-carbons (CFCs) are extremely stable, non-flammable, non-toxic and harmless to handle. It is ideal for air conditioners, refrigerators and fire extinguishers etc . Halons are similar to the CFCs dangerous to ozone layer.

18. The CFCs and Halons migrate into the upper atmosphere after they are released. As they are heavier than air, they are carried by air currents and reach upper atmosphere. This is a slow process and even take few to many years . In the stratosphere unfiltered UV radiation severs the chemical bonds releasing chlorine from CFCs. This attacks the ozone molecule resulting in its splitting into oxygen molecule and an oxygen atom. Thus leading to ozone depletion.

19. Effects of ozone depletion On human- sunburn, cataract, skin cancer, weakens the immune system Food production – uv radiation causes reduction in photosynthesis – reduces nutrient contents and the growth of plants On materials- damages paints and fabrics causing them to fade faster. On climate- global warming – Green house effect- increase in concentration of certain gases like carbon di oxide, nitrogen oxides, methane, CFCs trap heat in the form of infra red radiation near the earth’s surface- Green house effect

20. Effects of Green house effect Polar ice caps will melt causing rise in ocean levels. Fall in agricultural produce. Changes in habitats – climatic conditions.

21. Smog is a type of large-scale outdoor pollution. It is caused by chemical reactions between pollutants derived from different sources, primarily automobile exhaust and industrial emissions. Cities are often centers of these types of activities, and many suffer from the effects of smog, especially during the warm months of the year.

22. Control measures Proper fuel and exhaust system in vehicles Use of dry and wet collectors, filters, electrostatic precipitators. Providing greater height to the stacks – discharge pollutants away from the ground. Substitution of raw materials that cause more pollution.

23. Water pollution 71% of earth’s surface is covered by water-but only a tiny fraction is available as fresh water. 97% of total water is found in oceans and 3% is fresh water. Out of this 2.997% is locked in ice caps. The only 0.003% of total volume is available as soil moisture, ground water, water vapour, water in lakes, streams, rivers and wetlands.

24. Definit i on When the quality or composition of water changes directly or indirectly as a result of man’s activities such that it becomes unfit for any purpose it is said to be polluted.

25. Types of water Surface water- water found in streams, rivers and lakes etc. Ground water- that percolates into ground Aquifers- porous water-saturated layers of sand, gravel or bedrock through which ground water flows. It is replenished naturally by rainfall.

26. Point source – source is known- eg. Municipal and industrial discharge pipes Non-point source- source is unknown- eg.agricultural runoff, acid rain

27. Sources of Water Pollution Water soluble radioactive isoptopes – radioactive wastes- ionizing radiation cause birth defects, cancer and genetic disorders. Hot water- thermal plants, nuclear power stations, power plants release water- Oil-leakage

28. Water soluble inorganic chemicals-acids, salts and compounds of toxic metals such as mercury and lead. Organic compounds-oil, gaseoline, plastics, pesticides, cleaning solvents, detergents etc. Sediment of suspended water- insoluble particles of soil and other solids that become suspended in water

29. Industrial Effluents : Water is discharged from industries after having been used in production processes. This waste water may contain acids, alkalis, salts, poisons, oils and in some cases harmful bacteria . Mining and Agricultural Wastes : Mines, especially gold and coal mines, are responsible for large quantities of acid water. Agricultural pesticides, fertilizers and herbicides may wash into rivers and stagnant water bodies . Sewage Disposal and Domestic Wastes : Sewage as well as domestic and farm wastes were often allowed to pollute rivers and dams.

30. Causes of water pollution Disease causing agents – bacteria, viruses, protozoa and parasitic worms enter water from domestic sewage and untreated human and animal wastes . Oxygen depleting wastes- large populations of bacteria use up the oxygen present in water to degrade wastes. The amount of oxygen required to break down a certain amount of organic matter is called Biological Oxygen Demand(BOD).

31. If too much organic waste is added, all the available oxygen is used up and causes organisms like fish to die . Anaerobic bacteria begin to break down the wastes producing chemicals that have a foul and unpleasant odour.

32. Inorganic plant nutrients-water soluble nitrates and phosphates that cause excessive growth of algae and other aquatic plants- called eutrophication. Biomagnification- pesticides- reach water- phytoplanktons-herbivorous fish-carnivorous fish- water birds-animals-human beings. At each stage the chemicals are concentrated resulting biomagnifiction. Eg.DDT

33. Control measures Prevention Setting up treatment plants Root Zone Process – using reefs

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36. Soil pollution Soil is s thin covering over the land consisting of a mixture of minerals, organic materials, living organisms, air and water. Under ideal climatic conditions soft parent material may develop into a centimeter of soil in 15 years.

37. Soil profile The top layer – O horizon- freshly fallen and decomposed leaves, twigs, animal wastes, fungi and other organic materials- brown or black in colour Uppermost layer- A horizon-partially decomposed organic matter and inorganic mineral particles – darker and looser B horizon – subsoil contains less aquatic material and fewer organisms than A zone. C horizon – weathered parent material

38. Causes of soil degradation Erosion By wind and water accelerated by human activities such as farming, construction, overgrazing by livestock, burning of grass cover, deforestation.

39. Excess use of fertilizers Fertilizers, insecticides, herbicides, pesticides, fungicides, rodenticides Soil fertility is lost Kill beneficial insects

40. Integrated Treatment Methods Continuous contour trenches or benches Live check dams – planting grass, shrubs and trees etc. Bund constructed out of stones. Earthen check bund- local soil,across the stream

41. Integrated Pest Management Organic farming Use of biofertilzers Earthworms- vermicomposting Pest control through microbes – Bacillus thrungiensis, Azadirachta indica- Neem

42. Marine Pollution The introduction of substances to the marine environment directly or indirectly by man resulting in adverse effects

43. Causes Direct discharge of wastes into sea – sewage Washed off materials- fertilizers, pesticides Petroleum, oils washed off from roads Spill of Toxic substances from ships Offshore oil exploration and extraction

44. Effects of marine pollution Eutrophication-phytoplankton blooms Oil slick – affect plants and fish Destroys flora and fauna

45. Control Measures Introduction of sewage treatment plants Primary treatment-physical process such as screening and sedimentation to remove pollutants that will settle, float etc. Secondary treatment- to remove BOD

46. Control measures for oil pollution Process of emulsification through chemical dispersants-sprayed on the oil. Biological methods- use of bacteria

47. Noise Pollution Noise is unwanted and undesirable sound Permitted noise level is 125 decibels

48. dB n sounds dB Environmental condition Threshold of hearing 10 Rustle of leaves 20 Broadcasting studio 30 Bedroom at night 40 Library 50 Quiet office 60 Conversational speech 70 Average radio 74 Light traffic noise 90 Subway train 100 Symphony orchestra 110 Rock band 120 Aircraft takeoff 146 Threshold of pain

49. Ambient noise levels dB Zone Day time Night time Silent zone 50 40 Residential zone 55 45 Commercial zone 65 55 Industrial zone 70 70

50. B Duration (hrs/minutes/seconds) dB 8 hrs 90 4 93 2 96 1 99 30 minutes 102 15 102 7 108 4 111 2 114 1 117 30 seconds 120 Instantaneous rupture of membrane 150

51. Effects of noise pollution Physical damage to ear- temporary thresh hold shift-TTS – hearing loss Mental fatigue

52. Control techniques Reduce noise at source Block the path of noise Increase the path length and protect the recipient

53. Thermal Pollution Sources- discharge of warm water into river Effects-changes the ecological balance of river Death of fish Effect on plants Control- passing the heated water through a cooling pond or cooling tower after it leaves the condenser

54. Nuclear hazards Nuclear fission –splitting of the nucleus of the atom – resulting energy is used for a variety of purposes Hot water Uranium waste – ionizing material

55. Effects of nuclear pollution Lethal Mutation Plants and animals Marine organisms-fish Skin diseases, cancer, eye disorders etc.,

56. Control measures Away from the cities Proper disposal mechanisms Safety measures

57. Role of an individual in prevention of pollution Develop respect to all forms of life Try to plant trees where ever you can Reduce the use of paper and wood products where ever possible – use recycled paper Do not buy furniture, doors etc., made from teak – forest based Help in restoring a degraded area Join in an aforestation program

58. Advocate organic forming Avoid use of pesticides Reduce fossil fuel – coal, petrol etc. save petrol Shut of the lights and fans when not needed- save electricity Do not use aerosol spray products do not pour chemicals, paints pesticides in the drain

59. Use rechargeable batteries Do not use cans, avoid plastics – plastic carry bags Recycle paper, aluminum, plastics Set up compost bin in your garden Start community composting Keep you and your place clean

60. Environmental protection begins with YOU!!!

61. Thank you