500 MAN CONTROLS HIS ENVIRONMENT FOR HEALTH 



Practical Exercise 27. What general facts have you learned about refriger- 

 ation ? What types of refrigerators are most efficient ? The most costly to pur- 

 chase ? The most costly to run ? What recommendation would you make for 

 the average small family living in the country? In the city? 



Practical Exercise 28. What insects are household pests ? Which of these 

 damage foods? What would you do to rid a house of ants? Roaches? 



Practical Exercise 29. Is cold-storage food as good as fresh food? Give 

 reasons for your answer. Recent tests have shown that the majority of cheap 

 ice boxes do not keep the temperature below 50° F. Such boxes usually have 

 the ice wrapped in newspapers when it is put in the box. What effect does 

 the paper have on the efficiency of the ice box? 



Home water supplies. We have already learned why water 

 which comes from a shallow well or unprotected spring should be 

 carefully tested and protected against pollution. Ice for use 

 in drinking water should be carefully washed, for experiments 

 show that although nearly all bacteria in ice are killed after storage 

 of a few weeks, yet disease germs are often found on the outside of 

 pieces of ice because it is handled by disease carriers or persons of 

 careless personal habits. Water coolers and filters are usually 

 traps for bacteria and are often dangers rather than aids in sani- 

 tary living. Moreover, a water cooler in a house is frequently ac- 

 companied by a common drinking cup. 



Practical Exercise 30. Show what you would do to protect a home water 

 supply of uncertain purity. Make a report to the class. 



Disposal of wastes. In country homes where cesspools receive 

 human wastes, great care should be used in locating them, espe- 

 cially if the water supply is from a shallow well. A septic tank 

 costs little more to install and is much safer than the ordinary 

 cesspool. In city houses the disposal of human wastes is pro- 

 vided for by a system of sewers. Garbage should be disposed 

 of each day. The garbage pail should be frequently sterilized by 

 rinsing it with boiling water and plenty of lye or soap. Remember 

 that flies frequent the uncovered garbage pail, and that they fly 

 from it to your food. 



Practical Exercise 31. Make a diagram for your workbook to show the 

 method of sewage disposal in your community; in your home. 



Find out the method of garbage collection and disposal in your town. 

 Make suggestions for improvement of this service, if needed. 



