292 Microbes and You 



concentration to result in vomiting within a few minutes after 

 ingestion. 



Arsenate of lead, a common spray employed to kill pests on 

 fruit trees, may cause severe illness to individuals who purchase 

 fresh fruits, and eat them without proper washing. Persons en- 

 gaged in industries dealing with paints, batteries, gasoline, glazes 

 for pottery, and insecticides are exposed to unhealthy concentra- 

 tions of lead unless suitable precautions are observed. 



Many chemicals, including formaldehyde, boric acid, potassium 

 permanganate, hydrogen peroxide, and others, have been discon- 

 tinued as preservatives in foods since passage of the Food and 

 Drug Act of 1906 and its revision more than twenty years later. 

 Each year tighter controls on foods, drugs, and cosmetics are 

 necessary in the interests of public health and welfare. State and 

 national agencies charged with this watch-dog responsibility are 

 doing creditable work in assuring the public that they are getting 

 what they are paying for, and that dangerous products are not 

 being sold on the open market without proper labeling. 



POISONOUS PLANTS AND ANIMALS 



Poisonous mushrooms, snakeroot, water hemlock, and rhubarb 

 leaves may produce gastro-intestinal symptoms similar to those as- 

 sociated with microbial food poisoning. Water hemlock resembles 

 parsnips or carrots as it grows in swamps or in wet meadows. 

 When food was scarce during the first World War, the use of 

 rhubarb leaves was recommended for human consumption to 

 supplement the diet with leafy vegetables. Time proved that 

 chemical constituents of the rhubarb leaf were toxic to humans and 

 increased the clotting time of blood to dangerously high levels. 



PREVENTION OF FOOD POISONING AND INFECTION 



To summarize briefly, most suffering from food poisoning can 

 be avoided by the application of the following precautions: 



1. No person should be permitted to handle food for public 

 consumption unless he understands and practices the essential 

 rules of sanitation, both with respect to the cleanliness of his 



