The mortality experienced by a cohort of 36 691 rubber workers during 1946-85 has been investigated. These workers were all male operatives first employed in any one of the 13 participating factories in 1946-60; all had worked continuously in the industry for a minimum period of one year. Compared with the general population, statistically significant excesses relating to cancer mortality were found for cancer of the pharynx (E = 20-2, 0 = 30, SMR = 149), oesophagus (E = 87-6, 0 = 107, SMR = 122), stomach(E = 316-5,0= 359, SMR = 113), lung(E = 1219 2,0 = 1592, SMR = 131), and all neoplasms (E = 2965 6, 0 = 3344, SMR = 113). Statistically significant deficits were found for cancer of the prostate (E = 128-2, 0 = 91, SMR = 71), testis (E = I I0, 0 = 4, SMR = 36), and Hodgkin's disease (E = 26'9, 0 = 16, SMR = 59). Involvement of occupational exposures was assessed by the method of regression models and life tables (RMLT). This method was used to compare the duration of employment in the industry, the duration in "dust exposed" jobs, and the duration in "fume and/or solvent exposed"jobs ofthose dying from causes ofinterest with those ofall matching survivors. Positive associations (approaching formal levels of statistical significance) were found only for cancers of the stomach and the lung. The results of the RMLT analysis are independent ofthose from the SMR analysis, and the study continues to provide limited evidence ofa causal association between the risks of stomach cancer and dust exposures, and the risks of lung cancer and fume or solvent exposures in the rubber industry during the period under study.

A statistically significant elevated risk of bladder cancer for the exposed workforce was evident, but this reversed when the carcinogen was removed from processing in October 1949. The use of morbidity (incidence) data in long-term studies of occupational bladder cancer should be the required methodology if the hazard and risk are not to be underestimated.

Although it is over 30 years since an excess of bladder cancer was first identified in British rubber workers, the fear has persisted that this hazard could still be affecting men working in the industry today. Furthermore, suspicions have also arisen that other and hitherto unsuspected excesses of cancer might be occurring. For these reasons 33 815 men, who first started work in the industry between 1 January 1946 and 31 December 1960, have been followed up to 31 December 1975 to ascertain the number of deaths attributable to malignant disease and to compare these with the expected number calculated from the published mortality rates applicable to the male population of England and Wales and Scotland. The findings confirm the absence of any excess mortality from bladder cancer among men entering the industry after 1 January 1951 (the presumed bladder carcinogens were withdrawn from production processes in July 1949), but they confirm also a statistically significant excess of both lung and stomach cancer mortality. A small excess of oesophageal cancer was also observed in both the tyre and general rubber goods manufacturing sectors. American reports of an excess of leukaemia among rubber workers receive only limited support from the present study, where a small numerical excess of deaths from leukaemia is not statistically significant. A special feature of the study is the adoption of an analytical method that permits taking into account the long latent period of induction of occupational cancer.The existence of an occupational bladder cancer hazard has been reco,nised in the British rubber industry since 1950,; the current position has recently been reviewed by one of us.5 During the early 1 970s epidemiological studies were extended on both sides of the Atlantic to the investigation of the total mortality pattern of rubber workers, but with special emphasis on deaths from cancer. It has for some time been suggested that other and hitherto unsuspected excesses of cancer could also be present in addition to the recognised excess of occupational bladder cancer. Unpublished preliminary observations using proportional mortality data collected in the course of a study of bladder cancer by the British Rubber Manufacturers' Association (BRMA) did provide some evidence of an excess of both lung and stomach cancers.On 1 February 1967 a survey6 was set up by the then senior medical inspector of factories to determine whether there was a continuing risk of bladder cancer in the rubber and cable-making industries.On that date a detailed census was undertaken in

Although it is over 30 years since an excess of bladder cancer was first identified in British rubber workers, the fear has persisted that this hazard could still be affecting men working in the industry today. Furthermore, suspicions have also arisen that other and hitherto unsuspected excesses of cancer might be occurring. For these reasons 33 815 men, who first started work in the industry between 1 January 1946 and 31 December 1960, have been followed up to 31 December 1975 to ascertain the number of deaths attributable to malignant disease and to compare these with the expected number calculated from the published mortality rates applicable to the male population of England and Wales and Scotland. The findings confirm the absence of any excess mortality from bladder cancer among men entering the industry after 1 January 1951 (the presumed bladder carcinogens were withdrawn from production processes in July 1949), but they confirm also a statistically significant excess of both lung and stomach cancer mortality. A small excess of oesophageal cancer was also observed in both the tyre and general rubber goods manufacturing sectors. American reports of an excess of leukaemia among rubber workers receive only limited support from the present study, where a small numerical excess of deaths from leukaemia is not statistically significant. A special feature of the study is the adoption of an analytical method that permits taking into account the long latent period of induction of occupational cancer.The existence of an occupational bladder cancer hazard has been reco,nised in the British rubber industry since 1950,; the current position has recently been reviewed by one of us.5 During the early 1 970s epidemiological studies were extended on both sides of the Atlantic to the investigation of the total mortality pattern of rubber workers, but with special emphasis on deaths from cancer. It has for some time been suggested that other and hitherto unsuspected excesses of cancer could also be present in addition to the recognised excess of occupational bladder cancer. Unpublished preliminary observations using proportional mortality data collected in the course of a study of bladder cancer by the British Rubber Manufacturers' Association (BRMA) did provide some evidence of an excess of both lung and stomach cancers.On 1 February 1967 a survey6 was set up by the then senior medical inspector of factories to determine whether there was a continuing risk of bladder cancer in the rubber and cable-making industries.On that date a detailed census was undertaken in

Pott, a British surgeon who described scrotal cancer in boy chimney sweeps. A century later, in 1895, Rehn, a German surgeon working in Frankfurt, treated a cluster of three cases of bladder cancer in workers at a local factory