Cancer incidence among seamen in Iceland

The cancer incidence was investigated among 27,884 fishermen and sailors from the merchant fleet who had been members of a pension fund for seamen during 1958-1986 in Iceland. The cancer incidence was followed through 1966-1988. Expected values were based on rates for the general male population in Iceland. In the whole cohort, 758 malignant neoplasms had occurred as compared to 688.43 expected, standardized incidence ratio (SIR) = 1.10, 95% confidence limit (CI) 1.03-1.18. There was an excess for cancer of the stomach, rectum, larynx, and lung and nonmelanoma skin cancer; the SIRs were 1.29, 1.44, 1.77, 1.61, and 1.51, respectively. When analyzing the cancer incidence according to length of employment, the SIRs for many of the cancer sites were high for those with a short employment and many SIRs decreased with increasing length of employment. The SIRs for lung cancer were high in all subgroups. Only for stomach cancer and leukemia was there a substantial increase in SIR with increasing length of employment. The SIR was 1.55 for stomach cancer (CI 1.01-2.27) in the group with longer than 10 years of employment, and 1.97 for leukemia (CI 0.85-3.87) in the same group. It is concluded that the risk of both stomach and lung cancer seems to be associated with the occupation of seamen.