During 1964, I visited CIRUS (a research reactor in Trombay) for the first time.It was a routine visit.I was then a trainee in the Atomic Energy Establishment Training School.Before allowing us into the reactor hall, the health physicist dutifully handed over to me a direct reading dosimeter, the type you clip on to your shirt. I had mixed feelings. There was a tinge of anxiety or was it fear? At the end of the visit, before the dosimeter was returned, I peered through. It did not record any radiation dose. My fear was due to ignorance.
If my recollection is correct, the group of visitors received only one dosimeter. I rushed in to collect it. Just in case! We are afraid of radiation because it cannot be felt, smelt or seen. We need special instruments to detect it.
Eight months earlier, just before we were recruited, we were sent for a medical examination. Four or five of us were inside the x-ray room. I peeped in when my friend underwent x-ray screening, a practice I will unequivocally condemn now. We waited there jiggling. We were not afraid of x-rays.
A few years later, I had opportunity to see closely how radiation safety is achieved in a clinical environment in one of the premier medical centres in USA. Once there was a radiological scare in the pathology laboratory. A biopsy sample from a patient contained a tiny metallic seed.While the technician placed the sample on the slide, she saw it and reported it to the pathologist. When they reviewed the patients file, they noted that five years earlier the physician had implanted a few gold seeds in to the floor of his mouth- a normal radiotherapy procedure to treat cancer in that location. An urgent call to the Radiological Physics Division settled the issue. Then the seed had no radioactivity. Radioactive gold is used for such treatment because they can be safely and permanently implanted and left in the tissue as radioactive gold has a short half life.
In biomedical research laboratories, radionuclides are routinely used. I was the subject in one such study.I ingested a small amount of potassium- 42. After a short while, the distribution of the activity in my body was studied by using a whole-body radioactivity monitor.This method is ideal to calibrate such counters. Potassium-42 has a gamma ray spectrum similar to potassium-40 the radioisotope of interest. The radiation dose to the body is pretty trivial.
One of my friends who had the same academic and professional qualification like me refused to be a subject. Any amount of rationalization was not enough to convince him. He used to smoke about 20 cigarettes a day, there by accepting a risk several times more than that from the research study involving the use of potassium-42.
Fear of radiation may vanish possibly if the effects, if any, are explained quantitatively. While nobody can support uncontrolled use of radiation, one should not lose sleep over radiation doses that are trivial.