Water by prof najeeb Memon

1. By:
Community Medicine Deptt:
BMC, LUMHS
Jamshoro, Sind, Pakistan e mail mnajeeb80@gmail .com
LIAQUAT
MEDICAL
UNIVERSITY

4. Water
FRESH WATER

5. Two thirds (2/3) of our
planet is covered by
water.
97.5% of the water is
saltwater.
The majority of freshwater
is beyond our reach,
locked into polar snow
and ice.

6. 66% of the human body
is made up of water.
At just 2% dehydration
your performance
decreases by around
20%.
We should drink at least
1½ litres of water a
day.

8. The number of
people with access
to clean water has
doubled in the last
20 years.
1.1 billion people in
the world still do not
have access to safe
water. This is nearly
20% of the
population.

9. 1. Safe water (Potable Water)
 Free from foreign materials including bacterias.
 Cleansing to Eyes.
 Delicious to taste.
2. Polluted water
 Contain harmful substances of all types
(Physical, chemicals)
 Including pathogenic organisms.
3. Contaminated water
 Contain harmful pathogenic organisms (fecal matter)

10. Sources of Water
 1. Rain
 2. Surface water
 3. Ground water / Sub surface water

11. Sources of Water
 1. Rain ( Prime source of all water )

12. 2. Surface water
 2. Surface water ( sources)
 River & streams Lake, ponds, tanks Impounding Reservoirs

13.  3. Ground water Springs
Shallow
Deep
Seasonal
Thermal
Mineral
Wells
 Shallow
 Deep
 Artesian

14. Wells
Deep
Artesian well
Shallow well

15. Sanitary well

16. Insanitary well

17. Springs
Shallow
Deep
Seasonal
Thermal
Mineral

18. Uses of water
 1. Domestic use 8%
 2. public purpose -
 3. Industrial & Emergency sector use 22%
 4. Agricultural use 70%

19. 22%
8%
70%
0
10
20
30
40
50
60
70
80
Agriculture Domestic Industry
Water uses
%oftotalwaterused

21. 1. Domestic use

22. Rough estimation of per animal /day
5 – 30 1 35 35 40-60 50- 70 50-70 75- 90 liters

23. Hydrological (Water) Cycle

24. The hydrologic (Water) cycle is the process, powered by the sun's energy, which
moves water between the oceans, the sky, and the land.
It can be studied by starting at any of the following processes:
evaporation, condensation, precipitation, interception, infiltration, percolation,
transpiration, runoff, and storage.

25. Water pollution
 1. Dissolved gases ( CO2, SO2, H2S, NH3)
 2. Agricultural Pollutants ( Fertilizer )
 3. Industrial wastes
 4. Sewage
( decomposing organic water & pathogenic agents)
 5. Sub – soil geology

26. Hazards of polluted water
 1. Biological hazards
 A. Bacterial: Typhoid, Cholera, Bac: Dysent:
 B. Viral: Polio, Hepatitis A & E
 C. Protozoal: Amoebiasis, giardiasis

27.  D. Helminthic: Round worm, Whip worm,
Hydrated disease
 E. Leptospiral : Weil’s Disease
 F. Cyclops : Guinea worm

28.  2. Other hazards:
 GIT disturbances ( due to Na, Mg & Ca ions)
E.g:- MgSo4, Lead to Diarrhoea
 Lead poisoning
 Iodine Deficiency
 Fluorine Deficiency
 Hardness of water
 Infant met haemoglobinemia

29. WHO Criteria for water Purification

30. Criteria for water Quality
 1. Physical Qualities
 2. Chemical Qualities
 3. Bacteriological Indicators
 4. Radiological standards

31. 1. Physical Qualities
 Turbidity : Must be free from turbidity ( < 5 NTU)
 Color : Must be free from color
 Odor : No odor ( Non objectionable / Acceptable)
 Taste : Must be palatable ( Non objectionable / Acceptable)

32. Turbidity
measurement
Nephelometric
Turbidity Units
(NTU’s)?

33. 2. Chemical Qualities( cont:)
Essential Inorganic mg/Litre
Antimony (Sb) <0.005
Cadmium 0.01 mg / L
Arsenic (As) 0.05 mg / L
Chromium (Cr) 0.05
Copper (Cu) 0.06
Aluminium (Al) <0.2
Boron (B) 0.3
Barium (Ba) 1.0
Chloride: 200 mg / L

34. Toxic Inorganic mg/L
Mercury 0.002 mg / L or less
Selenium 0.01 mg / L or less
Lead 0.05 mg / L or less
Magnese 0.05 mg / L or less
cyanide 0.05 mg / L
Free saline & Ammonia: 0.05 mg / L or less
Fluoride 1.4 – 2.4 mg/L
Hydrocarbons 0.01 mg / L or less
Total Hardness: 2mEq /L
Total solids 500 mg / L

35.  Nitrites : 3
 Zinc (Zn) 5
 Nitrates: 45 mg / L or less
 Residual chlorine 0.2-0.5 at consumer end
0.5-1.5 at source.
 Dissolve O2 Not less than 5 mg / L
 O2 absorbed
at 370C in 4 hrs: should not be > 1 mg / L

36. 3. Bacteriological Indicators
1. No sample should contain E. coli in 100 ml of water.
2. No sample should contain > 3 coliform / 100 ml of water.
3. Not > 5% of samples throughout the year should have
coliform in 100 ml.
4. No two consecutive samples should have coliform in 100
ml.