1150 



RADIATION BIOLOGY 



complicated by cancers; malignant growths can, however, be caused also 

 by ultraviolet radiation. 



A monograph by Hesse (1911) records fifty-four cases of roentgen 

 cancers. The pioneering spirit finds its expression in the large number of 

 cases reported from the United States of America (26) ; from Germany and 

 England each, 13 cases were recorded. Twenty-six of the fifty-four 

 patients were physicians and twenty-four, X-ray technicians. 



Feygin (1914) surveyed a number of cases of radiation-induced cancers 

 in relation to latent periods and duration of exposure as follows: 



The observations in man were soon verified by experimental studies in 

 animals by Marie et al. (1910, 1912) and his student, Clunet (1910), who 

 produced sarcomas in rats by repeated administration of X radiation. 

 Imitating the sequence of events in man, they waited until ulcers formed 

 and healed and then administered more X radiation. 



The similarity between the cutaneous changes caused by X irradiation 

 was recognized in 1900 by Walkhoff. The first casualty (1901) from 

 overexposure to radium radiations was Henri Becquerel himself. He 

 carried in his vest pocket radium enclosed in a glass tube. Erythema of 

 the skin followed by ulceration marked the site of the exposure. The 

 ulcer healed completely a month afterward (see Colwell and Russ, 1934). 

 It is now well established that a single local exposure is likely to cause a 

 neoplasm only under exceptional conditions, but a single massive expo- 

 sure to either X or y radiation over the entire body may often cause 

 cancers in some internal organs. 



Wolbach (1909) and Ordway (1915), working under the Cancer Com- 

 mission of Harvard University, studied in detail the injurious effects in 

 handlers of radioactive substances. The very first changes consisted 

 chiefly of flattening of the characteristic ridges, thickening and scaling 

 of the superficial layers of the skin, atrophy and intractable ulcerations. 

 These objective changes were slight compared with the subjective persist- 

 ing symptoms such as paresthesia, anesthesia, tenderness, throbbing, 

 and pain. Wolbach concluded that not a single trauma but long- 

 continued progressive lesions of connective tissue supporting the epi- 

 thelium are responsible for the acquisition of malignant properties. 



