Flight attendants have more cancers of the uterus, thyroid and other cancers, according to a study

The life of an air hostess may seem glamorous, but the job comes with health risks that go beyond the management of surly passengers. As a group, they get some cancers more than the general population, according to a new study.

Scientists have long recognized that flight attendants have more breast cancer and melanoma. The new study, published Monday in the journal Environmental Health, observed the same trend and detected a higher prevalence of all other cancers investigated by researchers: non-melanoma, uterine, gastrointestinal, cervical and thyroid skin cancers in flight attendants.

"Something that surprised us somewhat, to some extent, was that we also saw a higher case of breast cancer among women with three or more children," said study co-author Irina Mordukhovich, Harvard Research Associate TH Chan School of Public Health.

As a general rule, the longer a woman has children, the lower her risk of breast cancer is. A previous study showed a similar result to the new discovery of breast cancer, she said, but Mordukhovich did not expect these results to be replicated.

"Women with three or more children probably do not sleep enough," said Mordukhovich. "Combining that with this disruption of work, especially for those who fly abroad, this may be an indication that disruption of the circadian rhythm has an impact."

Disturbances to the circadian rhythm – a person's daily sleep-wake cycle – are linked to an increased risk of cancer, studies have shown.

The new study compared data on cancer cases reported by Harvard, which collects data to help people understand how their work can affect health, with cases being tracked in the National Health and Nutrition Review Centers for Disease Control Survey, an ongoing study that tracks the health and nutrition of adults and children in the general population. Eighty percent of the flight attendants in the study were women, as could be expected, according to the authors, in a "feminized" occupation.

The research does not answer why flight attendants report higher numbers of cancer, but the authors have some ideas, based on previous research.

Flight attendants are often exposed to possible or probable carcinogens such as pesticides, flame retardants, jet fuel and other chemicals more frequently than the general population. They are also exposed to higher levels of cosmic ionizing radiation; the World Health Organization says that it is a cancer risk.

If you travel a lot, should you worry about your own risk of cancer? Mordukhovich said that there is not much research on frequent travelers, although the logic suggests that they face similar exposures. Independently, NASA scientists have studied high-altitude radiation to help improve the monitoring of crews and passengers in the aviation industry.

Steve Fiering, a professor of microbiology and immunology at the Geisel School of Medicine in Dartmouth, said that it is difficult to argue with the idea behind the recent study.

Fiering, who has not participated in the study, but who is conducting research on flight attendants, said that higher rates of melanoma and non-melanoma skin cancer among women in the United States. "Striking" study – especially nearly four-fold increase in non-melanoma skin cancer, which is important, "he said.

Ms. Mordukhovich indicated that she and her colleagues were motivated to study flight attendants because there were gaps in research, which could mean gaps in policies to protect them at work, from less in the United States.

In Europe, the exposure of flight attendants to cosmic ionizing radiation is further monitored and limited by law. There is no official dose limit for US crews. In fact, it is only in 2014 that American flight attendants got protections from the Occupational Safety and Health Administration as other US workers, but even today, these protections are limited, said Mordukhovich.

"Our goal is to make science and provide more evidence to decision makers about the health of this profession," said Mordukhovich. "We hope it helps."

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