Environmental Toxicology

1. ENVIRONMENTAL TOXICOLOGY Chapter 9 Water Pollution Mohd Amir Bin Arshad 1

2. Introduction Water pollution is any chemical, physical or biological change in the quality of water that has a harmful effect on any living thing that drinks or uses or lives (in) it. 2

3. Water Pollution 3

4. Isu-isu di Malaysia…

5. Many rivers become polluted due to the wastes that have been poured out. Example: Paper making industry, requires chemicals in its production. The rivers are used as an outlet for the chemicals to drain away.

6. PendudukOrangasli?? 6

7. There are some of ethnic aboriginal groups that still exist in Malaysia and they depend on the rivers and streams to survive. They depend on the river for food, water supply for drinking, bathing and for their crops.

8. Pusat Pelancongan 8

9. Due to tourism purpose, forests surrounding the river areas have been chopped down. The surrounding soils have no roots to hold on to and soon erode when the rains come. The soil runs into the rivers and soon become murky. Threaten an aquatic life.

10. A good example is the construction of a new golf course near the waterfall at tourist attraction Fraser’s Hill in the state of Pahang. The impact, become extremely murky and dirty due to the silt and sand that comes from the construction. The waterfall has now lost all its attraction.

11. Tasik Chini & Pollution? Gambartasikchini 11

12. The lake water choked with coliform bacteria to levels “beyond imagination”. Also found in the well waters used by the orangasli in the surrounding area. Lake become 'blocked' sink. The water is stagnant. Sewage pipes from the camp lead straight into the lake. 12

13. 13 Main factor-built TasikChini National Service Camp.

14. Sources of Pollutions Point Source Non-Point Source 14

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16. Point Sources? Point sources discharge pollutants at specific locations (direct) through pipelines or sewers into the surface water. Examples of point sources are: factories, sewage treatment plants, underground mines, oil wells, oil tankers and agriculture. 16

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18. Non-point sources? Non-point sources are sources that cannot be traced (indirect) to a single site of discharge. Examples of non-point sources are: acid deposition from the air, traffic, pollutants that are spread through rivers and pollutants that enter the water through groundwater. Non-point pollution is hard to control because the perpetrators cannot be traced. 18

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20. Major Sources Domestic Industrial 20 Agricultural

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22. Domestic pollutants Wastewater generated from the household activities. It contains organic and inorganic materials such as phosphates and nitrates. Organic materials are food and vegetable waste, whereas inorganic materials come from soaps and detergents. 22

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25. public underground sewerage systems

26. septic tanks

27. pesticides

28. wastewater from dishwashers

29. car wash wastewater

30. washing machines, sinks, and baths.24

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32. Industrial Pollutants Caused by the discharged of industrial effluents. The industrial effluents contain organic pollutants and other toxic chemicals. Some of the pollutants from industrial source include lead, mercury, asbestos, nitrates, phosphates, oils, etc.

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35. Pesticides

36. Soil additives

37. Antibiotics/drugs

38. Animal wastesWashed off from the land to the aquatic system through irrigation, rainfall and leaching. 28

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41. Accident or disaster Oil spill is a major problem in the oceans and seas. The oil tankers and offshore petroleum refineries cause oil leakage into the waters. Oil floats on the water surface and prevents the atmospheric oxygen from mixing in the water. The oil enters the body of the organisms. It also coats the body of the aquatic animals and birds which may also kill them. 31

42. Impact Human Aquatic Life Environment 32

43. Effect to human Several type of disease/poisoning due to consumed of contaminated water. 33

44. Water-Borne Disease 34

45. Heavy metal poisoning Exposed to Arsenic, Lead, mercury, cadmium etc. 35

46. Eutrophication Eutrophication means natural nutrient enrichment of stream and lake water. Mainly caused by an increase in nitrate and phosphate levels in water. Due to the enrichment, water plants such as algae will grow extensively. 36

47. Eutrophication 37

48. Eutrophication Eutrophication also results in overgrowth of plants like Eicchornia that covers the entire surface of water. This reduces the light reaching the lower layers in water. As a result the water will absorb less light and certain anaerobic bacteria will become more active. 38

49. Eutrophication 39

50. Hypoxia (Oxygen depletion) Eutrophication leads to hypoxia. Enrich of nutrients promoting algae growth. Thus, water might turns into green. 40

51. Hypoxia (Oxygen depletion) Rich algal growth leads to great increase in the number of the decomposers. All these life forms-decomposers, algae, other plants, fishes and other aquatic animals, use the oxygen in the water for respiration. This causes great demand for oxygen and results in depletion of oxygen. 41

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53. Bad Smell of Water When water enriched with nutrients, eventually anaerobic bacteria will become highly active. These bacteria produce certain gasses during their activities. Example is hydrogen sulphide. This compounds smells like rotten eggs. When water smells like rotten eggs we can conclude that there is hydrogen present, due to a shortage of oxygen in the specific water. 43

54. Heat pollution Certain industries such as power plants, refineries, nuclear reactors release a lot of hot water from their cooling plants. Release hot water to water bodies without reduce the temperature. The warmer water decreases the solubility of oxygen in the water and it also causes water organisms to breathe faster. Organisms will die from oxygen shortages. 44

55. Acidification Industry emits great amounts of acidifying gasses, such as sulphuric oxides and carbon monoxide. These gasses also dissolve in rainwater. This causes a change in pH of the precipitation-the pH of rain will fall to a value of or below 4. The lower the pH, the more acid the substance. 45

56. Aesthetic Value 46

57. Biomagnifications Pesticide (DDT) not bio-degradable. These accumulate in the organisms. These organisms are fed upon by aquatic life (fish) to the man. These contaminants remain in the fats and are not degraded in the body. Over the years the amount of DDT increases in the body. 47

58. Biomagnifications Thus, pollutant reaches the body of man. At each step in the food chain, the contaminant increases in quantity. 48

59. Pollution is measured by knowing the biological oxygen demand (BOD). Low BOD = Little Pollution High BOD = Higher Pollution 49

60. Water Pollutants & Effects 50

61. Water Pollutants & Effects 51

62. Water Pollution Solutions 52

63. Charity begins at home 53

64. Enforcing Existing Laws 54

65. Control Development 55

66. Stop Deforestation 56

67. Preventing Oil Spills 57

68. Prevent Emissions 58

69. Love our environment…

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71. THANK YOU Any Questions? 61