I am concerned about the dangers of occupational exposure to cosmic radiation. Has any research been conducted to determine whether the incidence of various types of skin cancer is greater in people who fly for a living (e.g., pilots, flight attendants, frequent flyers, and military personnel) compared with the general public?— Marcia C. Ray, ARNP, Milton, Fla.

Epidemiologic studies of mortality and cancer incidence in pilots and flight crew have been performed (Occup Environ Med. 2003;60:805-806; available at oem.bmj.com/content/60/11/805.long, accessed May 15, 2013). Pilots are at increased risk of malignant melanoma, nonmelanoma skin cancer, and possibly acute myelogenous leukemia.

Flight-crew members are at increased risk for malignant melanoma and breast cancer. Cancer risk factors can be occupational exposures (longer flights at higher altitudes resulting in greater cosmic ionizing radiation dose rates, irregular working hours, and disturbance of circadian rhythm) and nonoccupational (lifestyle and reproductive history).—Philip R. Cohen, MD (176-3)

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