There have been several studies looking into health risks
associated with air travel, though often, it's the pilots who
are the focus of the investigation. A large European study,
Mortality from cancer and other causes among male airline
cockpit crew in Europe, finds in accordance with others that
there is a higher incidence of skin cancer in cockpit crews.
This has also been observed for cabin crews. However, they do
not find a dose-response, i.e. they cannot demonstrate that
flying more increases skin cancer risk, which is what you'd
expect if it was radiation exposure during the flight that was
causing cancer. Consequently, it is quite possible that it's
higher exposure to UV light in their time off work that puts
cockpit and cabin crews at a higher risk for skin cancer
compared to the rest of the population. In other words this BBC
article is overly sensationalist. Interestingly, mortality from
several other causes is lower in cockpit crews, possibly due to
selection effects, i.e. you need to be fit and h