Incidence Rates of Malignant Diseases in Swedish Fishermen

Author(s): Lennart Hardell

A cohort of fishermen was identified by Statistics Sweden by using the national census registration carried out from 1960 to 1990. The occupational title fisherman was used as surrogate for exposure to persistent organic pollutants (POPs) due to high fish consumption.

For each fisherman, 4 matched population based referents were drawn. Swedish cancer register 1960-1998, the causes of death registry 1960-1997, and notifications of deaths 1998-1999 were used to identify cancer cases. Mantel-Haenszel analysis was performed to calculate incidence rate ratios (IRR) and 95% confidence intervals (CI) for the different malignant diagnoses. An overall increased incidence rate ratio of cancer, IRR=1.17, 95% CI =1.11- 1.23 was found in fishermen. This was mainly caused by an increased risk for smoking related cancer sites such as lip, hypopharynx and lung. Increased IRR was also found for stomach cancer. An increased IRR was found for non-melanoma skin cancer probably caused by chronic exposure to UV-light among fishermen due to their out-door work.