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April 1960

Effect of Chloroquine on Erythematous and Carcinogenic Response to Ultraviolet Light: Demonstrated in Experimental Animals

AMA Arch Derm. 1960;81(4):570-576. doi:10.1001/archderm.1960.03730040074014

During a lifetime, exposed areas of the body are subject to large amounts of irradiation from sunlight. Unna was the first to call attention to the high incidence of skin cancer among sailors exposed to sunlight,1 and his observation on the relationship between exposure to sunlight and the development of skin cancers has been confirmed by many others. Also, epitheliomas have been produced experimentally by subjecting albino mice, rats, and rabbits to repeated exposures to ultraviolet rays produced by a mercury arc lamp.2-5 The carcinogenic wave lengths of the spectrum have been determined to be between 2,900 and 3,341 A. In experimental animals, the amount of effective midultraviolet radiant energy necessary to initiate changes which culminate with tumor formation is relatively small (63 to 84×107 ergs/sq. cm.).5 To a certain extent, the length of the precancerous period varies inversely with the daily dose of irradiation. Carcinogenesis, once