Filed under: Safety | Tags: Cremation, nuclear medicine, radiation, safety
Radioactive medicine has been developed and implemented at such a break-neck pace over the past decade that access to information regarding exposure has been slow to receive and difficult to understand. This has been a major source of concern for many crematory operators as it poses a possible risk to their health and safety.
To compound matters, even if there were concrete answers and solutions, crematory operators rarely get complete information. Details like: Does the body contain seeds? What type of radioactive material was used? How long have the seeds been implanted? and other such details are not known. It is very likely that the average crematory operator is already cremating bodies with these seeds and doesn’t even know it.
The use of radioactive seed implants is not new. This technique has long held promise as a method of delivering a very high dose of radiation while simultaneously reducing the amount of radiation to the adjacent organs. Early efforts in the 1970s and 80s were limited by a lack of effective technology to place seeds, causing uneven dosage of radiation. The results were suboptimal and this method was largely abandoned.
As the technology for medical imaging improved, efficient and effective means of planning and monitoring the placement of seeds were developed. The ability to accurately plan seed placement and verify seed position led to a renaissance of the implant technique. Another advantage of modern implant techniques is the avoidance of surgery: the seeds are placed by needles under anesthesia in an operating room environment.
What are these seeds?
Radioactive seeds are most commonly used to treat prostate cancer. Newapplications are always being developed though so it’s not necessarily safe to assume that just because the case is female, there is nothing to worry about.
The radioactive material is contained within a titanium “seed”. This seed is roughly the size of a grain of rice, but there can be as many as 130 of these seeds in a typical application. Two different radioactive sources are used: Iodine (I-125) or Palladium (Pd-103). The radioactive seeds can be implanted either temporarily or permanently, but the permanent form of implantation is most commonly used.
What can go wrong?
Typical cremation temperature ranges between 1400˚F to 1800˚F. Titanium melts closer to 3000˚F, so there’s little worry about the seed deconstructing in such a manner. The material in the seed boils around 1300˚F however and this combined outer temperature exposure and inner pressure from the boiling contents can cause a rupture.
So are we safe?
This may all sound rather unsettling, but consider the following facts:
- Both radioisotopes emit very low energy radiation and are primarily absorbed in the treatment area or “target” tissue immediately surrounding the seed, only a few millimeters from their location
- They gradually lose their radioactivity over a period of time – Iodine seeds over a period of about six months and Palladium seeds over a period of about three months.
According to the Canadian Nuclear Safety Commission, the main source of potential radiation exposure from the cremation of bodies that contain radionuclides is inhalation of ash particles during the cleaning of the retort. They further go on to say that it is exceedingly unlikely that any crematorium staff would come close to exceeding the annual dose limit for the public.
Regardless, it’s best to assume the worst. Operators should exercise universal precautions. Protective gear including gloves, eye protection and a quality particle mask should be worn at all time when cleaning out the chamber and handling the cremains for processing and packaging. This protection should be more than adequate to minimize exposure to any possible radiation emitting from these seeds.
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