Document ykYvLg55XVkOn3z4Yz7p756d

TUMORS OF THE SKIN 157 ployed in the crude paraffin departments of Scottish Oils, Ltd. Scott stated that these 19 cases represented a yearly incidence figure of 0.5 per cent. Two years later, Leitch quoted Scott to the effect that there had occurred, during the preceding 25 years, a total of 65 cases of paraffin cancer among workers employed in the shale oil industry of Scotland. In a treatise on anatomical distribution of occupational cancers prepared by Kennaway (1924), this in vestigator noted 19 cases of paraffin cancer in press men, referring apparently to cases included in the previously mentioned reports. In 1928 Scott reported again on this occupational neoplasm. He recorded that 89 cases of paraffin epitheliomata had been seen in workers of the Scottish shale oil industry during 1900 to 1928. Thirty of these cancers had affected men employed in the crude paraffin department, while an additional 59 cases were found in men of other grades of labor connected with the distillation and refining of shale oils. As approximately 5,000 men were employed by Scottish Oils, Ltd. an nually, the cancer incidence per year was 0.1 per cent or 2 per cent for the 28 years surveyed. This figure is remarkably low, because a large number of workers have been included in this statistical analysis, who had either none or no appreciable and prolonged contact with crude paraffin or the oils ex pressed from them. These statistical data are for this reason, grossly mislead ing as to the actual incidence of paraffin cancer among the restricted group of workers who are exposed to these agents to any considerable degree. Bridge and Henry reported in the same year and at the same occasion (In ternational Cancer Conference, London, 1928) that 28 cases of paraffin cancer had been certified during 1920 to 1926 to the Factory Department. This figure was increased by two new cases during the following two years (1928) and 6 additional cases were recorded up to 1931, according to the Annual Re ports of the Chief Inspector of Factories and Workshops for 1928 to 1931. The report in 1938 listed 9 new cases. The total number of paraffin carcinomas recorded in Great Britain since 1875 is about 150 cases. It cannot be maintained that this figure is near the actual number of cases which have occurred in this country, particularly before 1922. However, the number of recorded and actual cases of occupational paraffin cancer is relatively small, when compared with the number of oil carcinomas which have been placed on record from Great Britain. The first studies of this industrial neoplasm were made in England by Wilson, who collected, in 1910, data about the occurrence of scrotal carcinoma in mule spinners of the Lanca shire district caused by an occupational contact with lubricating oil (Brockbank and Stopford). Wilson observed, according to these investigators, from 1902 to 1910 at the Manchester Royal Infirmary 34 cases of scrotal cancer, of which 25 cases were present in mule spinners. Since a report of the RegistrarGeneral from the year 1885 mentioned that there were from 6 to 7 deaths yearly from scrotal cancer among the inhabitants of South Lancashire, and in view of the relative rarity of the scrotum as a site of cutaneous malignancy,