Community Medicine - Points to be noted

These are random quick revision points in Community Medicine (SPM)

1. For disinfection of large water bodies - Method of choice of chlorination is CHLORINE GAS. 

2. Chlorine gas is produced by PATERSON's CHLORONOME.

3. Greatest drawback of Chloramine is - SLOW ONSET of action.   

4. Perchloron / HTH has 60-70%  'Available Chlorine'. Whereas Commercial Bleaching Powder has only 33% 

Available Chlorine.


5. Yellow colour with O-Tolidine  Arsenite test is given by - Chlorine, Iron, Manganese and Nitrates.


6. Amount of Ozone required per litre : 0.2 - 1.5mg / Litre.

7. UV Rays used for water purification is 200 - 290nm .

8. D.D.T (Ziedler, Paul Miller)
       -- Invented by Ziedler
       -- Disinfecting properties was discovered by Paul Miller.
       -- No unpleasant Smell. No repellent action.
       -- TECHNICAL D.D.T - is the 70-80% Para-Para Isomer -- which is the most active form.
       -- It's a CONTACT POISON (Nerve).
       -- Residual action - 18 months.
       -- DOSE : 5% - 1 Gallon / sq.ft OR 100 - 200mg / sq.ft.
    
9. DIELDRIN (5-8 x) >> H.C.H ( 2x) >> D.D.T(x) ....where x is the Strength of DDT.

10. Dieldrin is absorbed through intact skin, other 2 does not.

11. LINDANE is PURE HCH containing 99% of gamma isomer is called as Lindane, 3 months residual action only.

12. Organophosphate Compound with least toxicity : Malathion.

13. Compounds used for Ultra Low Volume Fogging : Malathion, Fenitrothion, Sumithion.

14. Abate : Organophosphate - Low toxicity - Anopheles Stephensi, Dracunculiasis.

15. Compounds used for DDT resistant vectors  - Diazinon, Propoxur(Baygon).