One possible explanation for these increased rates is that flight attendants are exposed to a lot of known and potential carcinogens, or cancer-causing agents, within their work environment, said lead study author Irina Mordukhovich, a research associate at Harvard University's T.H. Chan School of Public Health.
Previous studies also recorded a higher cancer risk in cabin crew.
While these results confirm earlier research linking work as a flight attendant to an increased risk of certain cancers - especially breast and skin malignancies - the study wasn't created to prove whether or how the job might directly cause tumors.
"This is striking given the low rates of being overweight and smoking in this occupational group".
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%).
Having three or more children-or none at all-was also a risk factor for breast cancer in female flight attendants.
A study of more than 5,000 USA flight attendants has shown they have higher rates of certain cancers than the general public.
Already the USA flight attendants union released a statement on the study, saying it will "use the results to encourage airlines, airline manufacturers, and regulators to prevent exposures and change working conditions to reduce risk".
Mordukhovich found higher prevalence of breast, melanoma, uterine, gastrointestinal, thyroid and cervical cancers among the flight attendants compared to the general public. This type of radiation is particularly damaging to DNA and is a known cause of breast cancer and nonmelanoma skin cancer, she said.
"Our findings raise the question of what can be done to minimize the adverse exposures and cancers common among cabin crew". Even when flight attendants reported having stereotypically good health, diet, and exercise regimens, the likelihood that they would be stricken with certain cancers was still higher than the other survey respondents.
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. On average, attendants were 51 years old and had been working in the profession for just over 20 years.
"Neither OSHA nor the FAA require airlines to educate flight attendants about onboard radiation exposure or offer protections during pregnancy, cabin air can be contaminated, and cabin crew fatigue is prevalent", Nelson, president of the Association of Flight Attendants-CWA, said in a statement.
Previous research by scientists in Iceland suggested stewardesses were up to five times more likely to contract breast cancer.
One of the most unusual risks is cosmic ionizing radiation (radiation from outer space that penetrates airplanes). But there are no limitations or regulations in the USA on how much exposure is safe for flight attendants.
Other studies have found higher rates of deaths from cancer among cabin crew and higher rates of specific diseases such as chronic bronchitis and cardiac disease in flight attendants than the general population. That exposure may not be concerning for people taking individual flights, but for people whose jobs involve flying, that risk may have a negative effect on their health, as the study results suggest.