LECTURE

• Environmental health


  The art of conservation and promotion of public health
• Phases of environmental health

  1. Water sanitation - Preventive measure against diseases
• Types of water

  • Potable water
  • Polluted water
  • Contaminated water
• Potable water


  Efas, clean, free from contaminants and pollution
• Polluted water


  Suffered impaired on its physical qualities
• Contaminated water


  Infectious agents, toxic or poisonous
• Rain water


  Fresh water, distilled pure water
• Surface water


  Natural flow of water, rivers, lakes, springs, streams
• Underground water


  Below the layers of the earth usually clean and safe
• Piped water


  Distributed to houses
• Impurities in water

  • Physical impurities
  • Chemical impurities
  • Biologic impurities
  • Radiologic impurities
  • Bacteriologic impurities
• Physical impurities


  Inert suspension of floating substances carried by water that cause cloudiness or turbidity
• Chemical impurities


  Dissolved constituents of water, for the color of water
• Biologic impurities


  Microscopic plants and animals
• Radiologic impurities


  Discharge of radioisotopes and other radioactive wastes into water courses
• Bacteriologic impurities


  Presence of specific groups of bacteria
• Environmental health - art of conservation and promotion of public health 
• Phases of EH 

  1. water sanitation - preventive measure against diseases
• Types of water 

  1. potable water - efas, clean, free from contaminants and pollution
  2. polluted water - suffered impaired on its physical qualities
  3. contaminated water -infectious agents, toxic or poisonous
• • rain water - fresh water, distilled pure water 
  • surface water - natural flow of water, rivers, lakes, springs, streams
  • Underground water - below the layers of the earth usually clean and safe
  • Piped water - distributed to houses
• Impurities in water

  • Physical impurities - inert suspension of floating substances carried by water that cause cloudiness or turbidity
• • Chemical impurities - dissolved constituents of water, for the color of water
• • Biologic impurities - microscopic plants and animals
• • Radiologic impurities - discharge of radioisotopes and other radioactive wastes into water courses
• • Bacteriologic impurities - presence of specific groups of bacteria
• Water analysis


  Quality and safe of any given water supply
• Chlorinated water


  0.1mL of water & 3% of solution of sodium thiosulfate
• Sample volume


  Not less than 100ml
• Physical examination


  • Find out physical attributed of water (color, odot, taste, clearness)
• Chemical examination


  • Determine the chemical impurities of water
• Microscopic examination


  • Presence of aquatic planktons, algae
• Bacteriologic examination


  • Number of bacteria present constitute to health hazard
• Standard plate count


  Total viable population of bacteria present in sample
• Test for coliform

  Escnerichia coli - index of fecal contamination and serves as an indicator group
• Stages of water analysis

  1. Presumptive test - samples known to be heavily polluted

  2. Confirmatory test - supportive evidence for the presence of coliform organisms

  3. Completed test - Re-examine morphologically the typical coliform colonies
• Aeration - exchange of gas, peculiar taste and odor are removed
• • Softening - removing calcium and magnesium salts
• • Fluoridation - dental carries or tooth decay especially among children
• • Contact treatment - activated charcoal as absorbent
• Food sanitation - health hazards and the sanitary features of food handling