216 Microbes and You 



Under controlled conditions, chlorophyll does exhibit deodoriz- 

 ing properties, but the substance has limitations. The public has 

 been greatly impressed with the claims made for this material, 

 and as long as advertising makes clever appeals the average person 

 will continue to purchase these products. 



While on the subject of dentifrices, it might be of interest to 

 inject a note about how toothbrushes might serve as fomites in the 

 transmission of upper respiratory infections, particularly the com- 

 mon cold. Many household bathrooms still have a porcelain con- 

 tainer for holding the array of family toothbrushes. Even though 

 each person may have his own brush, much of this sanitary care 

 can be nullified when the wet brushes are allowed to rest on the 

 rack surface where pools of water can collect and permit migration 

 of organisms from one brush to another. Toothbrushes should 

 hang with the bristle end down, with sufficient space between the 

 brushes to prevent direct contact, and the location should allow 

 rapid drying of the bristles. Qualitative as well as quantitative 

 studies might well be undertaken on this phase of disease dis- 

 semination by fomites. 



FLUORIDATION OF PUBLIC WATER SUPPLIES 



A number of years ago it was observed that persons who drank 

 water containing fluorides appeared to have harder teeth and ex- 

 perienced less tooth decay than is normally found in the average 

 population. Certain sections of the United States, parts of Colo- 

 rado in particular, have water supplies in which the fluoride con- 

 tent is above the optimum for the prevention of dental caries, and 

 mottling (spotting) of the teeth is common in these areas. Re- 

 search has revealed that the ideal concentration of this chemical 

 appears to lie in the range of one part of fluorine per million parts 

 of water if mottling is to be prevented and if sound teeth are to 

 be expected. 



Since the natural fluoride content of most drinking water is too 

 minute to be of much value from the standpoint of dental health, 

 the practice of adding fluorine in the form of its salts to municipal 



