8,316 subjects, who had been employed in three tire factories in Shanghai for more than 1 year before December 31, 1972, were investigated in a retrospective cohort study to ascertain the relationship between digestive cancer and the job types in the rubber tire industry in Shanghai. Every subject was assigned to one of 27 jobs grouped into 8 types. The observation period was from January 1, 1967 to December 31, 1988. The Results show that several sites of cancer in the digestive system were associated with some main jobs in factories for both sexes. For example, stomach and liver cancers in workers in milling (SIR=202.8 and 229.2), inner tube curing (SIR=231.3 and 252.3) and material handling (SMR=209.6 for stomach cancer) in males; pancreatic cancer in tire curing (SIR=349.4) in males and in inner tube and tire buildings (SMR=372.5) in females; esophageal cancer in the production of non-tire products (SMR=275.31) in males; and rectal cancer in Building and Multiple jobs for non-tire work in males (SMR=483.7) and females (SMR=245.0). The authors thought the high incidence of cancer in the digestive system was a prominent phenomenon in several types of jobs in the rubber product manufacturing industry.
