Flight attendants pose higher cancer risks

According to a recent study, flight attendants may be at higher than average risk of breast and skin cancer, but the reasons are not yet clear.

Harvard University researchers found that compared to women in the general population of the United States. In the United States, flight attendants had a 51% higher rate of breast cancer. In contrast, their melanoma and non-melanoma skin cancer rates were approximately 2- to 4-fold higher, respectively.

The study, which included more than 5,300 US flight attendants, is not the first to find higher cancer risks in airline crews.

But it is one of the largest and most comprehensive that has examined the problem, according to senior investigator, Eileen McNeely.

What remains unclear is why the pattern is observed. And as it was an observational study, she could not show that there was causation.

Flight crews are exposed to several things that could play a role, said McNeely, professor of environmental health at the School of Public Health at Harvard University.

"There has been a lot of speculation about exposure to cosmic ionizing radiation," he said.

It refers to the radiation that comes from space. At altitudes reached by planes, people are exposed to higher levels of radiation. The National Institute for Safety and Health at Work (NIOSH) states that of all American workers who are exposed to radiation, the flight crew has the highest average level.

But no one knows for sure if cosmic radiation is to blame because flight attendants are more at risk for getting cancer, McNeely said.

Flight crews can also come in contact with various substances, he said. And before the entry into force of the ban on smoking, they usually breathed second-hand smoke.

In addition, said McNeely, flight crew members face constant changes in time zones and irregular sleep schedules, which means that they suffer from numerous disturbances of pace circadian body or "internal clock".

Disturbances in the circadian rhythm that occur when one works shifts have been associated with higher risks of obesity and diseases such as diabetes and heart disease.

It's hard to pinpoint which of these factors might be more important than the others, or whether it's a combination of all of these factors, McNeely said.

But it is also possible that there are factors unrelated to the work of the flight attendants, said Dr. Paolo Boffetta, professor of oncology and environmental medicine at the Icahn School of Medicine in Mount Sinai, New York.

] "For example, they may be more exposed to UV rays [solares] because of the opportunity that they have to travel," said Boffetta, who did not participate in l & # 39; study.

In addition, he said, women in the flight crew can delay the time to have children or have fewer children, compared to other women. And reproductive factors of this type are associated with the risk of breast cancer.

Yet, McNeely said, his team found evidence that the more flight attendants had this job, the higher their risk of cancer. In women, the risk of melanoma-free skin cancer increased with the age of employment.

This supports the theory that workplace exposures are to blame, McNeely said.

The results, published June 25 in the journal Environmental Health, are based on 5,366 flight attendants who participated in an ongoing study at Harvard University that began in 2007.

They have completed a survey on their health in 2014-2015, when they were on average 52 years old. The McNeely team compared their cancer rates with a nationally representative sample of 2,729 adults with similar demographic characteristics.

In total, 3.4% of flight attendants were diagnosed with breast cancer, compared to 2.3% of other women in the United States. On the other hand, 2.2% had been diagnosed with melanoma, compared to just under 1% of other women.

The greatest difference was observed in non-melanoma skin cancer rates, which are highly curable. Just over 7% of flight attendants were diagnosed with cancer, compared to just under 2% of other women.

Male flight attendants had higher rates of skin cancer than other men. But the differences were not statistically significant.

According to McNeely, the findings will be "no novelty" for the flight crew. They have known for a long time that their work could be associated with an increased risk of cancer.

The question is: if the causes are not clear, what can be done? McNeely said that the European Union has already taken action: require that the radiation exposure of the flight crew be monitored. If a certain level is reached, their work schedules are adjusted.

There is no official radiation limit for US flight crews. UU., According to NIOSH.

Boffetta said that for whatever reason, the highest rates of skin and breast cancer in flight attendants point to a significant problem: they should be recommended for cancer screening.

Potential risks to the flight crew pose another question: what about frequent flyers?

McNeely says that it's not clear if they are facing health risks. "We study workers first because they are the ones who expose the most," he said. "They are like the canary in the coal mine."