Authored By:
Miura et alThis study was a systematic review and meta-analysis of 12 previously published articles that investigated the risk of melanoma and keratinocyte cancers (KC) in airline pilots and cabin crew. The studies included in the analysis consisted of both retrospective and prospective cohort studies and provided data on both the incidence of these cancers and the resulting mortality as established by death registries, death certificates and physician records. The authors reported that, based on the available evidence, airline pilots and cabin crew had approximately twice the risk of developing melanoma and other skin cancers when compared to the general population. For melanoma incidence the pooled Standardised Incidence Ratio (SIR) was 2.03 (95% Confidence Interval (CI) 1.71-2.40) for airline pilots and 2.12 (95% CI 1.71-2.62) for cabin crew. This was similar for KC in pilots (SIR: 1.86 (95% CI 1.54-2.25) and cabin crew (SIR: 1.97 (95% CI 1.25-2.96). Further, airline pilots were about twice as likely to die from melanoma pooled Standardised Mortality Ratio (SMR) of 1.99 (95% CI 1.17-3.40). This higher mortality rate was not observed in cabin crew. The exposure agents considered as possible explanations for the higher than normal risk factors were occupational ultraviolet radiation (UVR) exposure and cosmic ionising radiation.
The authors assessed that both pilots and cabin crew were not occupationally exposed to UVR as it was not detectable in the cabin of modern airliners and pilots were exposed to no higher than levels encountered on the ground during their flights. However, the study was not able to take into account recreational UVR exposure. Both pilots and cabin crew are recognised as being the highest exposed occupations to ionising radiation from cosmic rays and in this study this was assessed by measures including duration of employment, type of licence and cumulative flight hours. Exposure to cosmic radiation, recreational UVR exposure and disruptions in circadian rhythm due to crossing time zones on long haul flights were considered to be potential explanations for the higher risk factors of melanoma and KC within pilots and cabin crew.
Published In:
The British Journal of Dermatology, December 2018This review included studies of airline crews where the data was collected mostly between the 1970s to the 1990s, with some data covering the period from 1947. Therefore, the evidence is outdated and the relevance to modern air travel is uncertain. However, the reported higher risk to airline crew of developing skin cancer is a useful indicator for the direction of further research. This research currently includes dose assessments of exposure to cosmic radiation. Further, the recreational solar UVR exposure of airline crew may need to be investigated.
