[Epidemiologic study of the mortality among the employees of a coal tar distillery]

A mortality study was carried out, throughout the period 1970-1984, in a cohort of 963 men who had worked for at least one year in a coal tar distillery. The observed number of deaths, 109, did not significantly differ from the expected number. Using the death rates of the local population as a reference, no excess was observed for lung cancer and for cancers of the larynx, while there was an excess for cancers of the oesophagus but non significant and for cancers of the buccal cavity and pharynx (SMR = 2.17 - p less than 0.05). A nested case-control study was carried out. From within the cohort, 5 deaths from lung cancer and 10 deaths from cancers of the buccal cavity and pharynx were defined as "cases". For each case, all the available dead controls with the same sex, year of birth, tobacco and alcohol consumption were selected from within the cohort. The odds ratios for lung cancer did not reveal any occupational risk. With regard to buccal cavity and pharyngeal cancers, the odds ratios were neither significant for a duration of exposure greater than or equal to 1 year nor for a duration greater than or equal to 5 years along with a latent period greater than or equal to 10 years. Nevertheless there is a significant OR for exposure less than or equal to 10 years (OR = 7.56) but it is near one for exposures greater than 10 years.