Two hundred and seventy-one men seen in 1963, who worked in a pulp and a paper mill, were followed up ten years later, in 1973. Death certificates were obtained for those who died. There did not appear to be any increased mortality in the group, nor was there any increased specific cause of death. A morbidity study of 200 men seen at both times did not show any differences in respiratory symptoms or prevalence of chronic non-specific respiratory disease. Analysis of pulmonary function showed little, if any, difference between groups. Analysis of retired, deceased, and still-working categories did suggest that exposures to Cl2 or SO2 might have a slight adverse effect on pulmonary function.In 1963 we made a cross-sectional study on a group of men who had been working in a pulp and a paper mill in Berlin, New Hampshire, USA (Ferris et al., 1967). Our purpose at that time was to see whether the exposure at work had an effect on chronic non-specific respiratory disease or pulmonary function. That study showed that the workers had less chronic non-specific respiratory disease than the general population, but the older men who had been exposed to chlorine and who were cigarette smokers had slightly lower expiratory flow rates at 50, 25, and 12-5 % of vital capacity than the men who had not been exposed to chlorine.In 1973 we restudied that cohort to determine whether they had a higher mortality than expected, or had developed respiratory disease.
Methods
PLANT PROCESSESThe pulp mill complex contained two chemical pulp mills-one a Kraft mill and the second a sulphite mill and, in addition, a chlorine plant. The sulphite mill and chlorine vlant were phased out after 1963, and the Kraft process increased. In both mills, wood chips are introduced into large