The researchers studied the rates of malignant melanoma in pilots
who worked for Icelandic airlines and compared them with data from
the national cancer registry of people of the same age. There were
five cases of malignant melanoma in the pilots while only 0.5 cases
would be expected based on population data. Rates for pilots flying
international routes were 15 times higher than expected, and 25
times higher for pilots flying routinely from Iceland to the United
States.
The results are consistent with other studies of cancer in airline
pilots, but the authors acknowledge that the small number of cases
makes it difficult to draw substantive conclusions. Previous research
by Danish scientists has shown that pilots and other cabin crew
also had a higher risk of leukaemia, which was believed to be due
to increased exposure to cosmic radiation.
The high risk of malignant melanoma appears to be exacerbated by
jetlag. Regular flights over several time zones increased the risk
even further.
The authors acknowledge that pilots have other occuptional and
lifestyle factors that affect the risk of skin cancer, such as exposure
to sun, engine exhaust gases, ozone, and cosmic radiation. Bigger
and better studies should now be done, they conclude.