Hi, Dr. Z – I was reading through some of our regs the other day (not for fun – I was looking something up – I’m not crazy, just a little bored) and I started wondering where they came from? How did people come up with the first radiation regulations and safety standards?
You know, that’s a great question! Until Roentgen and Becquerel discovered radiation and radioactivity there was no need for regulations, and, in fact, had they remained laboratory curiosities they still likely wouldn’t have been required…for that matter, had radiation and radioactivity been found to be harmless we wouldn’t have needed to have safety standards either. And that’s sort of how the first safety standards were developed – as the first scientists noticed that they and their assistants were developing burns and proved to themselves that these burns were from x-rays they started to develop guidelines for working safely with radiation.
The early medical use of x-rays began almost immediately after Roentgen announced his discovery and, by today’s standards, the exposure times and radiation doses were appalling. It’s not surprising – nobody knew anything about the new phenomenon, they didn’t even know how much radiation they were producing or how much was needed to pass through the body and bones to produce an image, they didn’t know how to get a good image without harming the patient. Knowing nothing at the start, the doctors were building a new discipline from scratch. So they started off by putting the x-ray tube up next to the patient and turning it on for a half hour or more; patients were suffering radiation burns, swollen hands and ears and heads, loss of hair, and a lot of pain. Based on the injuries we can estimate that patients were receiving a skin dose of hundreds to well over 1000 rem, with one of Thomas Edison’s assistants, Clarence Dally, receiving as much as 3000 rem to his hands – enough that his hands required amputation. By 1902 a review found that 88 cases of x-ray injury had been reported, 55 in 1896 alone. In 1904, Dally became the first person reported to have died from radiation exposure, followed by more over the next two decades.
During this time physicians had competing priorities. Consider: before x-rays were discovered, medicine had absolutely no way to see inside the body; they could only guess at the location of foreign objects (e.g. bullets or swallowed keys) or whether a bone was bruised or broken and they didn’t want to give up the new near-miraculous ability. On the other hand, the Hippocratic Oath admonishes physicians to “first do no harm.” In the first few decades of the last century physicians began developing guidelines to help them see inside the body without burning the bodies they were imaging. Yet even the most rigorous physicians were still exposing their patients, assistants, and themselves to doses of radiation that, today, would be considered unacceptably high. But it was a start.
In 1909 insurance companies began looking askance at the number of radiation injuries from medical x-rays but with the onset of First World War the need for x-ray machines in hospitals both at and away from the front was so great that radiation safety was largely ignored. Following the war, the use of radiation expanded still more, seeing it used to treat all sorts of issues, including removal of unwanted hair, treating infections, and even trying to see if criminals’ brains looked different than “normal” ones. Radioactivity was being used increasingly in both medical and non-medical settings, including patent medicines and glow-in-the-dark products. This was accompanied by still more radiation injuries and a growing awareness of the need for standardized safety practices. And around the same time people were starting to succumb to cancer who’d been exposed to radiation at levels too low to cause radiation injury; it dawned on the medical community that radiation-induced cancer could have a decades-long latency period and that even lower levels of radiation exposure could be dangerous. This led many national advisory bodies to recommend safety practices for their members; unfortunately there was still no international consensus. Not until 1928, anyhow – that’s when the first International Congress on Radiology convened and published the first set of detailed international consensus standards: how thick lead shielding should be around x-ray machines as well as rooms in which radium was stored, the size and temperature of x-ray rooms, and more.
Here’s the thing – the risks from radiation were beginning to be known, but they still didn’t know enough and many of these first standards were simply the ICR’s best guess. What was really needed, though, was study on how much dose it took to cause these health effects, and to do that the scientists and physicians had to develop a system of units and to learn to measure radiation exposure accurately and reliably. By the 1930s the American physicist Arthur Mutscheller had measured about how much radiation exposure would produce skin reddening (similar to sunburn) called the “erythema dose,” proposing a monthly limit of 1% of that dose. Other scientists around the world were converging on similar levels and in 1934 the American committee on this subject recommended a dose limit that came out to about 6 rem monthly – more radiation exposure than I’m allowed to receive in an entire year now.
Over the ensuing years and decades we learned more about both the short- and long-term health effects of radiation exposure and, as a result, the limits started coming down. And as we got better at the practice of radiation safety – especially during the Manhattan Project – regulations and other safety standards began to branch out to cover more circumstances, more work conditions, more types of exposures, more types of radiation-producing equipment, more categories of people being exposed…more of everything.
The process never ends. When I buy a radiation dosimeter I need to make sure it meets the appropriate standards developed by the American National Standards Institute (ANSI); when I recommend instruments for purchase at work they have to conform to other ANSI standards. I’ve had instruments tested by the National Institute of Standards and Technology (NIST) to make sure they work properly, and I’ve helped develop standards and guidance documents myself (believe me, it’s a long and exacting process). Most of the dosimeters and instruments I use today would have been considered science fiction to Mutscheller and the others who developed those first standards, and the early committees likely never expected that their work would be expanded to include nuclear reactors, linear accelerators, or the aftermath of radiological or nuclear attacks. And who knows how they’ll change in the future – all we know is that they will.
Resources:
https://en.wikipedia.org/wiki/Wilhelm_R%C3%B6ntgen (Roentgen)
https://en.wikipedia.org/wiki/Henri_Becquerel (Becquerel)