INCIDENCE OF CANCER AND EXPOSURE TO TOLUENE DIISOCYANATE AND METHYLENE DIPHENYLDIISOCYANATE - A COHORT BASED CASE-REFERENT STUDY IN THE POLYURETHANE FOAM MANUFACTURING-INDUSTRY

Objective-To assess the association between occupational exposure to t oluene diisocyanate or methylene diphenyldiisocyanate and risk of canc er. Design-A cohort based case-referent study. Study base-7023 subject s employed during the period 1958 to 1987 in nine Swedish polyurethane foam manufacturing plants. Main outcome measures-Odds ratios adjusted with respect to the matching factors (age at risk, calendar year at r isk, sex, and plant), calculated from the conditional logistic regress ion model. Results-A non-significant association was found between hig h exposure to isocyanates and prostate cancer (OR 2.66, 90% confidence interval (90% CI) 0.39-18.1), which was not enhanced when an inductio n latency period of 10 years was applied. An association between isocy anate exposure and colon cancer was even weaker. No associations were seen for non-Hodgkin's lymphoma and rectal cancer. Conclusions-The ten tative associations, derived from a previous cohort study, between iso cyanate exposure and excess risk for nonHodgkin's lymphoma and rectal cancer were not supported. Instead, non-significant associations with prostate cancer, and possibly colon cancer, were seen.