Commercial airline pilots appear to have a greater risk than the rest of the population when it comes to developing a particular type of skin cancer known as malignant melanoma. While melanoma is relatively rare, it is more dangerous than other types of skin cancer because it is more likely to metastasize or spread to other parts of the body, and carries a high mortality rate.
The melanoma rate was 10 times higher in a group of 458 commercial airline pilots from Iceland than in the general population of that country. For example, there were five cases of melanoma in the pilots while only 0.5 cases would be expected based on population data, according to the researchers from the University of Iceland and the Icelandic Cancer Registry. No malignant melanomas were found in pilots flying less than 5,000 hours. However, 2 cases of malignant melanoma (40 times the national average) were found in pilots flying between 5,000 and 9,999 hours and 3 cases (13 times the national average) in pilots flying 10,000 or more hours.
Four cases of the skin cancer were seen in pilots who had flown international flights over 5 time zones compared with only one melanoma in a group of pilots who had never crossed five time zones. We found extremely high rates for this particular type of skin cancer (malignant melanoma). The results are consistent with a few other studies looking at cancer in airline pilots, but the authors note that the small number of cases make it difficult to conclusively determine that the pilots do indeed have a higher risk of the cancer.
Airline pilots are exposed to a number of different, potentially-hazardous factors, including engine exhaust gases, ozone and cosmic radiation -- a type of radiation exposure that increases the farther an individual is from the earth's surface. It also suggests that circadian rhythms, the ''body clock'' that can be disrupted when people cross time zones, should be studied as a possible risk factor as well. The excess of malignant melanoma among those flying over five time zones suggests that the importance of disturbance of the circadian rhythm should be taken into consideration in future studies.
Occupational and Environmental Medicine;2000:57:175-179