Sunday, August 5, 2012

GOOD HEALTH LESSON 2: CLEAN WATER SUPPLIES



CLEAN AND PURE WATER
Clean and pure water is essential to maintain health.

DISEASES
If water is not clean, diseases such as diarrhoea, cholera, hepatitis (liver disease), guinea worm disease, and typhoid fever can result from drinking the water. 

  Schistosomiasis (bilharzia) is spread when the person swims, wades or washes in infected water.    Contaminated drinking water may spread Amoebiasis.
  Taeniasis infections can be spread by water that has been contaminated by tapeworms.  

  Dysentery with resultant diarrhoea can be spread by contaminated water. 
  Poliomyelitis can be transmitted through contaminated water.

PURIFY WATER
It is best to drink water from a pure water system.   If this is not possible, all water should be boiled before drinking. 
  Do not offer the boiled water to anyone to drink until it has cooled. 

  Keep all flies, mosquitoes and dust away from the surface of the water. 
  If you are in a very dusty area, and do not have a fridge, make sure you have netting to place over the water.

- According to the Washington State Department of Health, boiling is the safest way to purify water.   Bring the water to a rolling boil (where the water bubbles and rolls around the top of the container - be careful not to burn yourself on the boiling water) - for one minute. 
  Let the water cool before drinking.

Water taken from wells, rivers or holes for drinking, even when it looks clean, may spread disease. 
  Therefore, always boil water before use. Be careful not to swim in water which has not been proven by testing to be clean. 
  Diseases can be spread from the water into the skin, and can be very distressing.

A good and safe water supply should be free from harmful bacteria (germs), and should not contain too much chemicals or salts. 
  It should look clear (not cloudy, full of grit, dirt, worms, sand) and should have no smell or taste. 

WHERE DOES WATER COME FROM?
All water supplies come from rain. Some water sinks into the ground and can be reclaimed through wells, boreholes or springs. 
  Some water forms the water of rivers and dams. 

Rain water is usually relatively clean. Rain water can provide a good source of water if collected into clean tanks for storage. 
  It is still best to purify it by boiling. 

Surface Water
Surface water is the rain water which drains from an area which we call the catchment area. 
  This water forms rivers, lakes or dams.

Underground Water
A good amount of rain water sinks into the ground until it reaches a water table, or layer of rock. 
  It then collects there, and can be accessed by a well or borehole. 

The level of the underground water may be shallow or deep. 
  A shallow well can run dry after long droughts. A deep well may give a more permanent supply of water, such as the water in oasis in the deserts. 

WATER PURIFICATION
A simple water filtration system can be made. Slow sand filtration method can be used. 

The World Health Organisation explains that slow sand filtration may not only be the cheapest and simplest, but also the most efficient method of water treatment. 
  In areas of Africa, a drum is sometimes filled with clean sand, the water is poured in at the top and drips out of a pipe or tap at the bottom, clear and pure. 
  Wash and clean the sand regularly, new sand if possible should preferably be used. 


Washington State Department of Health
http://www.doh.wa.gov/Emergencies/EmergencyPreparednessandResponse/Factsheets/WaterPurification.aspx

Waterborne diseases
http://en.wikipedia.org/wiki/Waterborne_diseases

WHO Slow Sand filtration
http://www.who.int/water_sanitation_health/publications/ssf9241540370.pdf

With thanks to doh.wa.gov, wikipedia.org and who.int

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