Flight attendants had a higher prevalence of every cancer that was examined, especially breast cancer, melanoma, and non-melanoma skin cancer among women, echoing multiple USA and European studies. In addition, melanoma rates were more than two times higher and nonmelanoma skin cancer rates were about four times higher in female flight attendants compared with women from the general population.
These included those of the breast (3.4% against 2.3%), womb (0.15% against 0.13%), cervix (1% compared to 0.7%), gastrointestines (0.47% compared to 0.27%) and thyroid (0.67% compared to 0.56%).
These elevated cancer rates were observed despite indications of good-health behaviors, such as low levels of smoking and obesity, in the flight-attendant group as a whole, the study authors said. About 15 percent of the participants reported ever having been diagnosed with cancer, a higher prevalence than the general population. These data were then compared with the data received from a survey done on a group of people not belonging to the airline occupation.
Other studies have linked shift work and disrupted circadian clocks to higher risk of breast and prostate cancers, possibly due to a reduced ability of DNA to fix itself and the way circadian rhythm processes may be connected to immune function.
"Something that somewhat surprised us, to some extent, was that we also saw a higher instance of breast cancer in women with three or more children", Mordukhovich said, adding that flight attendants with three or more children possibly do not get enough sleep.
Previous studies also recorded a higher cancer risk in cabin crew.
Although it's still not a proven link, the researchers writing in Environmental Health think US airlines could do more to protect flight attendants from the perils of radiation and abnormal sleep patterns.
"In the European Union, air crew's radiation exposures are monitored and their schedules are created to minimize their dose, especially while pregnant".
A flight attendant speaks to a captain.
This was compared with data from 23,729 men and women with similar economic status who participated in the National Health and Nutrition Examination survey during the same years. In women, the risk of skin cancer other than melanoma increases for every additional five-year flying experience.
Over 5,300 USA -based flight attendants took part in the Harvard Flight Attendant Health Study between 2014-2015, although the results have only just been published.
The Harvard researchers began studying flight attendants' health more than a decade ago, launching the Harvard Flight Attendant Health Study. Cabin crew members are also regularly exposed to more UV radiation than the general population, which can make these workers more vulnerable to skin cancers, Mordukhovich said.
Plane stewards are routinely exposed to several known and suspected carcinogens, including altitude-based radiation.
Male caregivers also have a 50% greater risk of skin melanoma (1.2% vs. 0.69% in the general male population) and about 10% increased risk for skin cancer other than melanoma (3.2% versus 2.9%).