Cross-sectional Study of Respiratory Symptoms and Pulmonary Functions in Rayon Textile Workers with Special Reference to H2S Exposure

A cross-sectional study on pulmonary functions and respiratory symptoms was undertaken in Japanese male workers in 18 viscose rayon plants to detect pulmonay effects associated with viscose exposure, especially to H2S. Measurement of the occupational exposure level (OEL) of H2S by personal passive diffusion dosimetry, and the forced expiratory flow-volume test before and after an eight-hour shift on the same workday was undertaken in 30 matched pairs of exposed and non-exposed workers. The OEL of H2S was 0.3 to 7.8 ppm, 3 ppm on the average, for the viscose exposed workers and less than 0.1 ppm for the referents. No significant difference in the eight-hour pulmonary function changes between the pairs was observed, and no significant correlation between the individual pulmonary function changes and individual OEL of H2S was obtained. Indices of the forced expiratory flow-volume test for 324 workers appeared to be better in exposed non-smokers than in non-exposed non-smokers. The prevalence rates of respiratory symptoms in 2379 exposed and 2968 referent workers using a modified self-administered BMRC questionnaire showed significant associations with smoking habits, but not with rayon work-history. No evidence of any appreciable effect of viscose exposure on pulmonary functions and symptoms was revealed in the Japanese rayon plant workers.