ABSTRACT
Our earliest knowledge concerning chemical carcinogenesis came from clinical observations in humans. In 1775, Percivall Pott, an eminent English physician and surgeon, described the occurrence of cancer of the scrotum in a number of his patients. The common history given by these individuals was their employment as chimney sweeps when they were young. On the basis of this observation, Pott, with remarkable insight, concluded (1) that the occupation of these men as young boys was directly and causally related to their malignant disease and (2) that the large amounts of soot to which they were exposed was the causative agent of the cancer. Strangely enough, Pott did not suggest avoidance of contact with soot as a means of prevention, although his report in 1775 apparently inspired the Danish Chimney Sweepers’ Guild to rule 3 years later that its members should bathe daily. While the publication of Pott soon led other observers to attribute cancer of various sites to soot exposure, there was a relative lack of effective impact of his work on British public health practice during the succeeding century (Lawley, 1994). It was not until more than a century later that Butlin (1892) reported the relative rarity of scrotal cancer in chimney sweeps on the European continent compared with those in England. It appeared that the lower incidence of the disease on the continent was the result of frequent bathing and protective clothing.
