Abstract
BackgroundAirline crew are exposed to ionizing radiation as part of their occupation and have a documented increased risk of melanoma and cataracts. However, whether their occupation predisposes them to an increased risk of thyroid cancer is not established. The purpose of this systematic review and meta-analysis was to assess the risk of thyroid cancer in airline cockpit and cabin crew compared with the general population.MethodsThe MEDLINE database accessed via PubMed and Cochrane Database were searched. We included cohort studies reporting the standardized incidence ratio (SIR) or standardized mortality ratio (SMR) of thyroid cancers in any flight-based occupation.ResultsOf the 1777 citations retrieved in PubMed, eight studies with a total of 243,088 aircrew members and over 3,334,114 person-years of follow-up were included in this meta-analysis. No relevant studies were identified on Cochrane Database. The overall summary SIR of participants in any flight-based occupation was 1.11 (95% CI, 0.79–1.57; p = 0.613; 6 records). The summary SIR for cockpit crew was 1.21 (95% CI, 0.75–1.95; p = 0.383; 4 records) and the summary SIR for cabin crew was 1.00 (95% CI, 0.60–1.66; p = 0.646; 2 records). The overall summary standardized mortality ratio for airline crew was 1.19 (95% CI, 0.59–2.39; p = 0.773; 2 records).ConclusionAirline crew were not found to have a significantly elevated risk of thyroid cancer incidence or mortality relative to the general population. Future research should capitalize on the growing occupational cohort dataset and employ innovative methods to quantify lifetime radiation exposure to further assess thyroid cancer risk in airline crew.
Highlights
Airline crew are exposed to ionizing radiation as part of their occupation and have a documented increased risk of melanoma and cataracts
While elevated early stage breast cancer rates might be more related to differences in parity and age of first birth than exposure to cosmic radiation [12], melanoma rates could reflect a true increase related to increased cosmic radiation
The summary standardized incidence ratio (SIR) for cockpit crew was 1.21 and the summary SIR for cabin crew was 1.00 (Fig. 2)
Summary
Airline crew are exposed to ionizing radiation as part of their occupation and have a documented increased risk of melanoma and cataracts. With less atmospheric protection during flights, airline crew are exposed to greater doses of radiation. This is estimated to add an additional 2–9 mSv per year [1, 5] to the typical annual exposure from natural background radiation of 2.4 mSv [6]. Airline crews may represent a natural experiment due to work conditions that increase circadian disruption and radiation exposure. Several cancers such as melanoma [8] and breast cancer [9,10,11] have been observed at higher rates in this population. UV radiation exposure may be a cause [13], and few studies have evaluated other risk factors that could underlie increased melanoma incidence, such as history of sunburn, on-ground sun exposure, and skin type [14]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
