RELATION BETWEEN WATER SUPPLY AND

HEALTH (XIV-2)

The problem. It was known that certain diseases could often be prevented by boiling all drinking water long before it was known that small living organisms cause disease. Effective

supply. What does the local death rate from typhoid indicate about the character of the water supply?

What to use. Data given on pages 161 and 165 of the text and that shown in figure 28; also, if possible, your local health officer's records regarding number of deaths from typhoid fever and the supposed or known sources of infection.

What to do. 1. The relations which exist between water supply and disease and how purification of water reduces disease may be determined as follows: Plot on the graph which shows the statistics for Ottawa, Canada (Fig. 29), the facts for your local city if they are available.

Questions. Is typhoid fever a controllable disease? Is your local water supply from clean wells or lakes, and is it delivered into the homes and used in such ways as to insure that water is not a means of carrying disease germs? How does the quality of the local water supply compare with that of your neighboring communities?

Suggestions for report. Write the history of some particular case about which you can get the evidence to show how the failure

nity and individual health.

Optional problems. How do the

leading American

FIG. 29. Reduction of typhoid in Ottawa, Canada and European cities

(After Joseph Race)

compare relative to proportionate deaths

from typhoid fever? How may any difference be explained? Are rivers likely to be the best source of water supply? What is the relation of flies to distribution of typhoid germs? Would there be danger of securing typhoid germs from flies if all typhoid material from persons ill with typhoid were sterilized? What are the reasons for a campaign to prevent the reproduction of flies? Can you prepare a series of large charts for an exhibit giving the facts on water supply and health?

WATER SUPPLY AND SEWAGE DISPOSAL (XIV-3)

The problem. One of the greatest dangers to health is from the fact that when water is contaminated by sewage, disease germs from the sewage may be distributed. Water which is unclean is objectionable, but water which carries disease germs is intolerable. Modern communities are making great efforts not only to keep sewage from contaminating their water supply but to make use of the sewage.

What to use. Data and observations regarding the local plan for disposal of sewage; records or descriptions of the systems used in two or three of the large cities of the country. These records may usually be secured free by writing to the city health departments or water-supply bureaus.

What to do. Determine what system of disposal seems to insure noncontamination of the water supply and at the same time to make the best disposal of the sewage.

Questions. Does your community have a municipal sewagedisposal system? If so, describe the principal features. Are most of the houses connected with the system? Is it important that all should be connected? What is the final disposition made of the sewage? Is this disposition safe as far as your community is concerned? Does it menace the health of any other community? If there is no sewage system in your community, why not? Would the installation of one be an important public improvement?

Suggestions for report. Prepare a summary, stating the principal facts and needs of your community with reference to the proper disposition and use of sewage.

Reference work. Read sections 180 to 185.

Optional problems. What are the best means of securing freedom from sewage contamination in rural communities?