Lung function was studied in 354 coke oven plant workers in the Lorraine collieries (Houilleres du Bassin de Lorraine, France) who retired between 1963 and 1982 The aim of this work was to study the long term effect of occupational exposure on lung function in retired coke oven workers from the HBL. This work is part of a study on mortality and morbidity in survivors.'7 It continues a previous study carried out in 1983 on mortality which showed an excess of mortality from lung cancer (standardised mortality ratio (SMR) = 2 51) with reference to the French male population.'8
Material and methodsThe study sample consisted of all the male workers from the two coke oven plants who had retired between 1 January 1963 and 31 December 1982 (536 subjects) and who were still alive on 1 January 1988 (354 subjects). They were born between 1902 and 1935. Executives were excluded from the study.The subjects were asked to attend a medical examination at the firm's occupational health centre. The protocol included a standard questionnaire, conducted by the occupational physician, concerning diseases treated or followed up for more than five years (cardiovascular, respiratory, digestive, infectious, and psychiatric diseases, traumas, cancers, etc), the questionnaire for the study of chronic bronchitis and pulmonary emphysema of the European Steel and Coal Commission (ECSC) of the EC,'9 and the notion of "regular overconsumption" of alcoholic drink. Because of low numbers we did not distinguish between smokers and ex-smokers. The respiratory symptoms taken into account were chronic bronchitis defined by a daily cough and phlegm for three consecutive months each year over a period of two years, wheezing or chest noises heard daily, day and night, and dyspnoea classified into five stages.To be aware of the respiratory symptoms in the period nearing retirement we sought information 316 on 12 May 2018 by guest. Protected by copyright.