An Arizona crematorium has tested positive for radiation contamination after a man with a neuroendocrine pancreatic tumor was cremated following radioactive treatment. Now, a review published in the Journal of the American Medical Association aims to answer just how big of a risk such exposure might present to crematorium operators.

Radioactive compounds known as radiopharmaceuticals are used in medical procedures such as chemotherapy in order to diagnose and treat disease. In 2017, a 69-year-old man in Arizona was diagnosed with a pancreatic neuroendocrine tumor and was treated with lutetium, a targeted form of therapy that delivers radiation as specifically as possible to cancer cells. But when the man exhibited symptoms of hypotension two days later, he was admitted to a different hospital where he died following complications from the disease.

“At the time of the death, we were unaware that he had died and was cremated,” Nathan Yu, the man’s treating physician at Mayo Clinic, told IFLScience. When Yu’s team became aware of the situation, they called Arizona’s Bureau of Radiation Control to learn that the state does not currently have regulations in place to notify crematoriums of possible radiation exposure by way of former patients who had undergone nuclear medicine procedures.

Cremating an exposed patient volatilizes the radiopharmaceuticals present in the body, which can then be inhaled by workers or left in the broader area, creating exposure concerns. A month following treatment, Mayo Clinic doctors surveyed the crematorium using a Geiger-Mueller detector. They found evidence of radiation contamination on equipment such as the oven, vacuum, and bone crusher in the amount of 5,000 to 25,000 counts per minute – a very small amount.

Urine analysis revealed that no lutetium was present in the crematorium operator. However, a different cancer-treating isotope called technetium did show up. Because the operator had not been treated for cancer, it’s likely that he was exposed to technetium during his work.

“We use a certain amount of radioactivity to treat or diagnose patients,” co-author Kevin Nelson explained to IFLScience. “When they’re given the radioactivity, then there is a certain amount of exposure resulting from that. In this particular case, both the quantity of radiation, lutetium contamination, and the technetium identified in the crematory operator’s urine is very small.”

Recent data suggests that 18.6 million nuclear medicine procedures were performed in the US alone, with nearly 40 million worldwide. As the authors note, safety protocols are well-established in patients but are often overlooked in postmortem procedures. Other case reports have described potential issues with cremating patients who have undergone radioactive therapies, but Yu says this is the first time actual contamination has been documented.

“The annual limit was unlikely exceeded in this situation, but [the findings] bring to light a mechanism of exposure that can possibly be avoided. Although the magnitude of exposure was not alarming in this particular case, with other radiopharmaceuticals at different therapeutic levels, volatilization, and subsequent inhalation we just don’t know those clinical facts,” said Yu.

Though it’s just one case study, the authors say their work illustrates a need for further research to understand how prevalent such events may be in order to establish safety regulations for those working in the postmortem world.