PUBLIC HEALTH ENGINEERING- france

france QnA

Mills-Reincke Phenomena

states that the provision of filtered or treated water to a community, there is also a reduction not only in death rates due to typhoid fever and other enteric diseases but also in death rates due to non-enteric diseases (non-intestinal)

Water-borne Diseases

diseases transmitted by contaminated drinking water

Water-washed Diseases

caused by scarcity and inaccessibility of water make washing and personal cleanliness difficult and infrequent.

• examples are scabies, skin and eye infections, etc.

Water-based Diseases

found in water that provides the habitat for intermediate host organisms in which some parasites pass part of their life cycle

• example is Schistosomiasis

Water-related Diseases

found in water that may provide habitat for water-related insect vectors of diseases like mosquitoes

Sanitary Survey

on-site inspection evaluated by the Sanitary Engineer of all conditions, devices, and practices in the water supply system that pose danger to health and well-being of consumers.

Chlorine

this disinfectant is also an oxidizing agent that immediately oxidizes impurities in water

Chlorine Demand

the amount of chlorine that must be added to the water just to oxidize all the impurities

Free Residual Chlorine

the hypochlorous acid (HOCl) that remains in the water after the entire chlorine demand has been completely satisfied.

• this is the most effective form for chlorine disinfection

• it kills pathogens almost instantly upon contact

Combined Residual Chlorine

forms when chlorine reacts with ammonia (or other nitrogenous compounds) present in the water.

• these reaction products are called chloramines

• they are very much less effective as disinfecting agents.

• work slowly but last longer in pipes

Total Residual Chlorine

sum of the free and combined residual chlorine

Breakpoint

the exact point where free residual chlorine first appears in the water.

• all ammonia and chloramines have been completely destroyed and the chlorine demand is now fully satisfied

Zero Demand Residual

all chlorine added to pure water appears as free residual

• only happens in water with no impurities

Iodine

ammonia and organic nitrogenous compounds have little effect on germicidal efficient because they do not form substitution compounds with ___.

• causes physiological effect of prolonged used (esp. in children) and allergy

Ozone

obtained by passing a current of dried and filtered air between two electrodes (plates or tubes) subjected to an alternating current

• does not depend on the pH value, temp, or ammonia content of water

Potassium Permanganate

rarely applied in water treatment for the purpose of disinfection

• effective against cholera bacteria but not against other pathogenic germs

Potassium Permanganate

creates a purple-brow precipitate which coats the walls of the tank. cannot be removed easily

Silver

provides already treated water with long-lasting protection against recontamination by germs. its ions curb the growth of germs

Low Pressure Quartz Mercury Vapor Lamp

a source of ultra-violet radiation which emits invisible light at a wavelength in the range between 200 and 300 nm

Ultra-violet Radiation

the germicidal effect depends on the electric power of the lamp and on the time of exposure of the water to the radiation

• it decreases with increasing distance between water and lamp

Type I Sanitation Facilities

on-site toilet facilities of the non-water carriage and water carriage types for rural areas which are sanitary latrines without water-seal bowls

Type II Sanitation Facilities

on-site toilet facilities of the water carriage type with water-sealed and flush type with septic vault or septic disposal facilities

Type III Sanitation Facilities

water carriage type of toilet facilities connected to septic tanks or to sewage facilities

Food Sanitation

deals with health hazards and sanitary features of food handling

Food Handlers

person that handle food

• cooks, waitress, servers

• milkers

• packers in processing establishment

Local Health Authority

the one who issues Sanitary Permit to food establishments before they could operate

45F or 7C

required temperature in the storage of all perishable and potentially hazardous foods

Annual Tuberculin Test

the annual test that the herd should undergo

Vitamin C

in sterilizing milk, the temperature should be ultra high but not high enough in order to not destroy this vitamin that is easily destroyed by heat

Vectors

arthropods or other invertebrates which transmit infection by inoculation into or through the skin or mucous membrane by biting, or by deposit of infective materials on the skin or on food or objects

Houseflies

Musca domestica

500-3000 Eggs

a female fly can lay how many eggs in her life

4 Weeks

lifespan of a fly

Cockroaches

Blatella Germanica