在医学院期间，我（George S. Liu）了解到辐射会增加患甲状腺癌的风险，此后便对飞行辐射对人体健康的长期影响产生了浓厚的兴趣。而这一问题也与我切身相关，每逢学校放假我总要乘坐洲际航班回家。在某次 飞行中，我想起了由前运输安全管理局举办的一场精彩绝伦的物理讲座，讲座中提到使用盖革计数器来测量飞行中的电离辐射。
Airline 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.
Methods
The 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.
Results
Of 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).
Conclusion
Airline 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.
期刊介绍：Cancers of the Head & Neck (https://cancersheadneck.biomedcentral.com/) is an open access, peer-reviewed journal dedicated to publishing articles on pre-clinical and translational research, as well as research related to the clinical management of head & neck cancers. This includes cancers of the oral cavity, pharynx, larynx, paranasal sinuses, nasal cavity and salivary glands. Articles related to the aetiology, pathophysiology, prevention, diagnosis, treatment and survivorship of these cancers are all considered.
