Breast Cancer Risks for Flight Attendants

According to the latest NIOSH Science blog, “Are Flight Attendants at Risk for Breast Cancer?” – during the course of their shifts, flight attendants face exposure to cosmic radiation at higher concentrations than the public generally experiences on the ground, may cross time zones, and work during normal sleeping hours.

All of these work conditions raise questions about potential occupational health hazards. Cosmic radiation is a form of ionizing radiation. Ionizing radiation is linked to risks for cancer and reproductive effects, but there are uncertainties about risk from cosmic radiation at the levels and durations of occupational exposure that flight crews may experience.

Similar uncertainties complicate scientists’ abilities to estimate similar risks from disruption of the body’s time clock and sleep cycle. At the National Institute for Occupational Safety and Health (NIOSH), scientists study these and other exposures in efforts to reduce uncertainty and better protect workers’ health and safety.

One of the potential health hazards associated with exposure to cosmic radiation and working during normal sleeping hours, or shift work, is breast cancer. In a new study in the Scandinavian Journal of Work, Environment & Health  – NIOSH investigators looked specifically at the question of whether a relationship exists between breast cancer and these work conditions, in addition to crossing time zones, while controlling for other factors that could affect breast cancer risk. They found that these work conditions were not statistically associated with an increased risk of breast cancer among flight attendants overall.

Among a subset of flight attendants with three or more births, however, these work conditions were statistically associated with a significantly greater risk of breast cancer. Although the associations found in this study among women with three or more births were strong, this subset of women was small at 15% of the total study group. For this reason, more research is necessary to confirm these findings, according to the investigators.