[Cohort study of the hypertensive effects of carbon disulfide in viscose rayon workers].

Records of blood pressure and body weight of CS2 workers were analyzed in relation to the levels of CS2 exposure at a Japanese rayon-producing fac tory. A cohort of 46 CS2 workers who had later been transferred to non-CS2 jobs showed first a statistically significant rise, which was then followed by two consecutive episodes of statistically significant falls in systolic blood pressure. These episodes corresponded precisely to the initial increase in CS2 concentration at workplaces due to the increased output of thicker threads, the subsequent decrease in concentration due to the improvement of the working environment and finally to the transfer of most of the members of the cohort to non-CS2 jobs. Body weight also revealed statistically significant changes corresponding to the changes in CS2 levels. Time-weighted average CS2 con centration of 329 air samples taken at the breathing zones of three spinners was 17.4 ppm in 1972. It is concluded that CS2 causes mild and reversible hypertension and that the CS2 concentrations of 15-20 ppm may not be com pletely safe when the exposure of workers is continuous throughout their workdays.