Cancer mortality among male workers in the Polish rubber industry.

The rubber industry, acknowledged by the International Agency for Research on Cancer (IARC) to be a cancer risk technology is, because of difficulty in identifying causal factors, the subject of intensive epidemiological studies in many countries. In the presented study, cancer risk in the rubber industry was evaluated on the basis of long-term observation (1945-1985) of a cohort of 6978 male workers employed in a rubber goods factory, predominantly engaged in producing rubber footwear. The reference group was the general male population of Poland. Standardized mortality ratios (SMRs), calculated by means of the person-years method, were used in the evaluation of death risk. The observation of a whole cohort indicated an excess of cancer, in general (approx 12%), lung cancer (approx 40%) and gallbladder cancer (approx fourfold). In the subcohorts, distinguished according to peculiarities of individual production sections, cancer risk of the large intestine and larynx was significantly increased. The highest cancer risk was found in compounding, mixing, milling and vulcanizing sections. Hence, beta-naphthylamine, benzidine and solvents (benzene) were used in technological processes in the past, bladder cancer and leukemia were considered as most specific for the rubber industry. In the cohort observed, the risk of death from bladder cancer was significantly increased only in those who had been employed during the years 1945-1953, namely during the period when beta-naphthylamine was in use. No excess of deaths from leukemia was observed.