Morteza Mortazavi - Department of Occupational Health, School of Public Health, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
Parvin Ahmadinejad - Department of Occupational Health and Safety Engineering, Shiraz University of Medical Sciences, Shiraz, Iran.
Sara Arjmand - Department of Occupational Health and Safety Engineering, Shiraz University of Medical Sciences, Shiraz, Iran.
Milad Derakhshanjazari - Military Health Research Center, Life Style Institute, Baqiyatallah University of Medical Sciences, Tehran, Iran.

Introduction: Aircrew is exposed to harmful levels of gamma radiation with unknown effects. This study aims to investigate occupational exposure to cosmic gamma radiation and its associated health effects among the aircrew members of Iran Airlines. Methods: This analytical cross-sectional study was carried out on the crew from four internal flights departing from Mehrabad Airport in ۲۰۲۱. The participants were divided into two groups of ۱۰۰ aircrew members flying on low-altitude and high-altitude routes, and the history of their  illnesses in the past thres years was extracted from medical records. The average annual effective dose (ED) of gamma radiation for the aircrew was measured by dosimeter (CEM DT-۹۵۰۱), and data analysis was done using SPSS۱۶ software. Results: This study found that the average annual ED of gamma rays was approximately ۱.۵ millisieverts higher in flight crews on high-altitude flights compared to the low-altitude ones. Moreover, a significant relationship was observed between exposure to gamma and occupational disease in the studied subjects (P < ۰.۰۵). Therefore, the risk of gastrointestinal, skin, and cardiovascular diseases was ۳.۵۵, ۳.۶۳, and ۱۲.۴ times higher for the crew on high-altitude flights compared with those on low-altitude flights. Conclusion: High-altitude flights are associated with increased exposure to gamma radiation, leading to a threefold higher risk of occupational diseases such as gastrointestinal, skin, and cardiovascular conditions among aircrew members. These findings highlight the importance of reducing health risks of exposure to gamma rays in aviation industry and emphasize the need for preventive measures to protect the well-being of aircrew personnel.

Health, Occupational Exposure, Gamma Rays, Staff, Mehrabad Airport.