Flying Occupations Linked To Melanoma Risk

Melanoma risk elevated among individuals with a flight-based occupation

medwireNews: Aircraft pilots and cabin crew are twice as likely to be diagnosed with melanoma than members of the public, suggests a meta-analysis published in JAMA Dermatology.

The standardised incidence ratio (SIR) for an individual with a flight-based occupation was a significant 2.21, with SIRS of 2.22 for pilots and 2.09 for cabin crew, report Susana Ortiz-Urda, from the University of California in San Francisco, USA, and co-authors.

The standardised mortality ratio (SMR) for any flight-based worker was 1.42, rising to 1.83 for pilots and falling to 0.90 for cabin crew, although only the pilot SMR reached statistical significance.

Further analysis by gender indicated that the summary SMR for women in any flight-based occupation was 0.61 versus a significant 1.87 for their male counterparts, the researchers add.

The meta-analysis included 19 studies with 266,431 participants and showed significant heterogeneity for the summary SIR and SMR values – further analysis attributed this heterogeneity to data for male participants and pilots, which may be due to differences in time spent in the air compared with female participants and cabin crew.

The authors note that while pilots and cabin crew have consistently been shown to have cosmic radiation exposure below the allowed dose limit, ultraviolent (UV) radiation risks have not been assessed for these occupations.

“The windshields and cabin windows of airplanes seem to minimally block UVA radiation, and it is known that, for every additional 900 m of altitude above sea level, there is a 15% increase in intensity of UV radiation”, the researchers explain.

“At 9000 m, where most commercial aircraft fly, the UV level is approximately twice that of the ground. Moreover, these levels are even higher when flying over thick cloud layers and snow fields, which could reflect up to 85% of UV radiation.”

Cumulative UV exposure for these occupations is therefore a “concern” and could explain the increased risk of melanoma found in the meta-analysis, conclude Susana Ortiz-Urda and team, who note that the findings have “important implications for occupational health and protection of this population.”

Reference

Sanlorenzo S, Wehner M, Linos E,et al. The risk of melanoma in airline pilots and cabin crew. A meta-analysis. JAMA Dermatol 2014; Online First 3 September. doi:10.1001/jamadermatol.2014.1077

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