Nuclear technologists work surrounded by radioactive materials all day. Radiographers operate X-ray equipment. And yet neither profession tops the list of jobs with the highest radiation-related cancer risk in America. Flight attendants do.Researchers pulled death certificate data for 12.7 million Americans across 503 occupations and sorted the cancer deaths by type in a study published in JAMA Internal Medicine. Flight attendants came out on top for radiation-related cancer mortality, with 6.9% of deaths in that group falling into that category. Pilots were second at 6.7%. Nuclear medicine technologists, the people you’d expect to top this list, came in 12th. Aircraft mechanics and assemblers, who spend their careers around planes but never accumulate flight hours, showed no elevated risk.The explanation is cosmic radiation. At commercial flight altitudes, Earth’s atmosphere provides far less shielding from high-energy particles streaming in from the sun and deep space. The higher the latitude, the weaker the protection. “Pilots and flight attendants accrue an estimated 3 to 6 millisieverts of cosmic radiation per year,” wrote lead researcher Vishal Patel of Harvard Medical School, “far exceeding the 0.4 millisieverts received by an air traveler taking 10 cross-country round trips per year.” Over a full career in the air, that exposure adds up.Why Flight Attendants Face America’s Highest Radiation-Related Cancer RiskThe research was designed to rule out coincidence, and it mostly does. For cancers with no radiation link, flight attendants and pilots ranked around the middle of all 503 occupations—no general cancer excess, just a very specific one. Breast, thyroid, prostate, melanoma, leukemia, multiple myeloma. “The checks held,” Patel told Time. “Aircraft mechanics and assemblers, who work around aircraft, jet fuel, and hydraulic fluids but never accumulate flight hours, showed no elevation.”The part that should bother people is the regulatory gap. The FAA formally recognizes flight crew as occupationally exposed to ionizing radiation, but unlike other radiation workers in the US, or flight crew in most other developed countries, American pilots and flight attendants are subject to no federal dose limits and no radiation monitoring requirements. “These findings support consideration of occupational radiation protections for aircrew members commensurate with their exposure level,” the study authors wrote. They’ve been flying unmonitored through one of the highest-radiation environments of any American worker, and the cancer data is now reflecting that.The post This Common Job Has the Highest Cancer Risk in America appeared first on VICE.