198 MUTATIONS 



tioned. Carbon monoxide is a widespread product of our urban civil- 

 ization. You might suppose general exposure to be negligible, but, 

 surprisingly, studies on the blood of individuals living in congested 

 city areas, with a large amount of traffic, have shown that there is a 

 constant carbon monoxide level, measurable by the carbon monoxide- 

 hemoglobin level of the blood. 



However, even large amounts of carbon monoxide are so tightly 

 bound to hemoglobin that there is essentially no free carbon monoxide 

 available for penetration into tissues. A report in the literature (38) 

 tells of a carbon monoxide suicide of a pregnant woman at term. 

 Carbon monoxide analysis was carried out on the fetal blood as well as 

 the maternal blood, and there was absolutely none detectable in the 

 former, despite the fact that the woman had enough carbon monoxide 

 to kill her. So I think carbon monoxide can be dismissed from con- 

 sideration. 



On the other hand, ozone and other oxidants which are components 

 of smog may well be mutagenic by analogy to other strong oxidizing 

 agents such as peroxides that are known to be mutagenic. The absorp- 

 tion of ozone and similar compounds and their fate in the body and 

 their mutagenicity in animal material are largely unknown, but this 

 is a potential hazard in that large numbers of people (at least in some 

 urban areas) are exposed to these atmospheric pollutants. 



Vitamins and trace metals require some consideration. You would 

 suppose that since these compounds are present naturally in the body, 

 they could be dismissed. But, unfortunately, the one class of drugs 

 with which people are most overmedicated is the vitamins, and the 

 trace metals which are added to vitamin preparations. There is an 

 enormous and wholly unwarranted across-the-counter sale of these 

 substances, which are ingested in great excess over the natural require- 

 ment. If excessive amounts were mutagenic, we would have a real 

 problem here. 



Particularly interesting is the practice of overmedicating with B 

 vitamins and ascorbic acid during pregnancy, when there is no evidence 

 of vitamin deficiency, but simply the idea that large amounts of vita- 

 min are probably healthful. Early pregnancy, as I have pointed out, 

 may well be a period of fetal sensitivity to mutagens. Dr. Zamenhof 

 will shortly present some data on mutagenic effects of ascorbic acid. 

 These vitamin preparations, which are multimixtures, have trace ele- 

 ments of all kinds added to them fairly randomly. Iron salts are very 

 common. I have seen preparations that include manganese, about 

 whose mutagenic capabilities we have already heard. This is a wide- 



