A further cohort study of workers employed at a factory manufacturing chemicals for the rubber industry, with special reference to the chemicals 2-mercaptobenzothiazole (MBT), aniline, phenyl-β-naphthylamine and<i>o</i>-toluidine

Abstract

It seems likely that some members of this cohort have had occupational bladder cancer. Confident interpretation is difficult because of small numbers in the exposed subcohorts, relatively crude measures of exposure assessment for the four chemicals under study, and presence of unconsidered potential chemical confounders. The simplest interpretation of the findings about bladder cancer may be that PBN (or a chemical reagent or chemical intermediate associated with its production at this factory in the 1930s and 1940s) is a bladder carcinogen. Priority should be given, however, to obtaining information on the cancer experience of other working populations exposed to PBN or to o-toluidine.