3 J Giles, Scienceproject2


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3 J Giles, Scienceproject2

  1. 1. June Holiday Science Project Submitted by: Giam Ze-Min Giles 3J (27)
  2. 2. What is Water Pollution? <ul><li>Water pollution occurs when quality of a water body is changed as a result of the entry of harmful substances. </li></ul><ul><li>More often than not these harmful substances come from man’s activities. Pollution of this nature makes streams, lakes an coastal waters unpleasant to look at, to smell and to swim in. Fish and other sea animals harvested from such waters are to eat. People who drink polluted waters can become ill and with prolonged exposure may even develop cancer. </li></ul>
  3. 3. How much water is available to us? <ul><li>Water is necessary for life on earth. </li></ul><ul><li>All living things contain it and it provides a home for many kinds of life. </li></ul><ul><li>70% of the earth’s surface is covered with water in the form of oceans, seas, rivers, streams etc with the vast majority in the form of salt water and very small amount of fresh water. Humans can only use fresh water. </li></ul><ul><li>Fortunately for all living things, water is recyclable in nature i.e. it is a renewable resource. </li></ul><ul><li>But, this natural process takes time and is dependent on climatic conditions . </li></ul>
  4. 4. What are the sources of water pollution? <ul><li>Water pollution may originate from the following sources: </li></ul><ul><li>Industries </li></ul><ul><li>Agricultural lands </li></ul><ul><li>Homes . </li></ul>
  5. 5. Industries <ul><li>Many industries discharge wastes directly into waterways. As the waste builds up, the water develops a foul odor. The building of waste also causes the amount of O2 in the water to drop, leading to the death of aquatic organisms. </li></ul><ul><li>Some industries also burn coal, oil and other fuels. This releases sulphur and nitrogen oxides into the air. These gases reacts with water in the atmosphere forming acids which return to the earth when it rains in the form of acid rain. </li></ul><ul><li>As acid rain drains into rivers and other waterways, fish, algae and other aquatic life may die or be drastically reduced in numbers. </li></ul>
  6. 6. Agricultural Lands <ul><li>On farms, large amounts of fertilizers and pesticides are applied. When it rains, these chemicals along with the soil drain into nearby trenches, canals and rivers, adversely affecting aquatic life and human health. </li></ul><ul><li>Sometimes, these chemicals seep deep into the soil entering the ground water system while the sediments cause the waterways to become cloudy and muddy. </li></ul>
  7. 7. Homes <ul><li>Wastes generated from households are also disposed of in nearby drains. </li></ul><ul><li>Garden chemicals, if not properly stored, oils from cars and acid from batteries can enter into nearby waterways. Most visible is the rubbish especially plastic and glass that are dumped into trenched and canals. </li></ul><ul><li>Households that rear animals on a small scale also produce animal waste which when disposed of in waterways has the same effect as fertilizers and raw sewage. </li></ul>
  8. 8. Effects of water pollution <ul><li>Spread diseases </li></ul><ul><li>Polluted water is dangerous to human health. People who drink polluted water become infected by waterborne diseases such as cholera, diarrhoea or typhoid. </li></ul><ul><li>Affects vital body organs </li></ul><ul><li>Harmful chemicals in polluted water prevent the proper working of the vital body organs such as the heart and kidney. </li></ul><ul><li>Causes toxic buildup in the food chain </li></ul><ul><li>Harmful chemicals such as pesticides from agriculture and heavy metals like lead and mercury from industries can build up in the food chain, where they reach toxic levels in fish and other sea animals. </li></ul>
  9. 9. Effects of water pollution <ul><li>Kills aquatic life </li></ul><ul><li>Polluted water kills fish, shrimp, other aquatic life and coastal vegetation e.g. mangroves. This means fewer fish to eat and also the loss of livelihood for many. </li></ul><ul><li>Runoff from agricultural lands also results in the rapid growth of algae and waterweeds which in turn make the waterways in impassable. </li></ul>
  10. 10. Effects of water pollution <ul><li>Causes algal bloom </li></ul><ul><li>Wastes like urea, animal manure, vegetable peeling provide food for tiny plants called algae. The more waste there is the more algae grows, this is algal bloom. Bacteria feed off rotting algae will in turn consume O2 in the water. As a result, fish and other type of aquatic animals will die as a result of lack of O2. </li></ul><ul><li>Causes flooding </li></ul><ul><li>When a lot of soil is washed away into rivers and trenches, this not only causes aquatic life to perish but also floods especially with heavy rainfalls. </li></ul>
  11. 11. Effects of water pollution <ul><li>Threatens sea-birds </li></ul><ul><li>The oil from oil spills coats the feathers of birds, hence reducing their waterproofing and insulating qualities. As a result, these birds die from exposure to cold water and air. </li></ul>
  12. 12. What can we do to help to prevent water pollution? <ul><li>Dispose of wastes properly </li></ul><ul><li>Do not throw wastes into drains out of convenience. </li></ul><ul><li>Dispose of garbage into proper disposal bins. </li></ul><ul><li>Never wash pesticides into trenches. </li></ul><ul><li>Never wash animal wastes into trenches. </li></ul><ul><li>Find out where to dispose harmful wastes and follow local governmental regulations. </li></ul><ul><li>Do not use excessive fertilizers </li></ul><ul><li>Use in minimum amounts and avoid applying them when it is raining. </li></ul>
  13. 13. What can we do to help to prevent water pollution? <ul><li>Desist (Stop) from breaking water mains </li></ul><ul><li>Breaking water mains is an offence and endangers the health of people as polluted water can easily enter the portable water supply system. </li></ul><ul><li>Clear clogged drains </li></ul><ul><li>Prevent the likelihood of flooding and mosquito breeding. </li></ul><ul><li>Fix leaks on cars immediately </li></ul><ul><li>Quick fixing reduces the chance of polluting waterways with oil and petrol. </li></ul>