Signs of radiation: meaning and history of appearance
What does the sign of radiation mean? For more than seventy years, the yellow warning sign, sometimes referred to as “three-leaf clover,” is familiar to mankind all over the world, but, in addition to it, there is another sign, though less well known, but intuitively understandable.
For hundreds of years, the image of the skull and crossbones was sufficient and necessary to convey the concept of poison. Until we started experimenting with radioactive compounds.
The symbol, which we usually associate with radiation or radioactive materials, was developed at the end of 1946 by a group of people working at the University of California, Berkeley Radiation Laboratory. At that time, the negative consequences of this phenomenon only began to manifest themselves so that they could be studied well enough and come up with some kind of warning sign. In fact, this symbol was originally intended only for local use at Berkeley, primarily in the form of signs and stickers.
Nelsu Garden, the future leader of the Health Chemistry group in Berkeley, is credited with promoting the symbol, which has since been officially recognized by the US federal government. The letter he wrote describing the origin of the symbol said that many people in the group helped “draw” a sign that would best symbolize the degree of danger, type of activity, etc., but at the same time, was simple. design.
Initially, the radiation sign was of a different color — the background was blue, and the shamrock itself was purple. But later, experimenting with colors, the scientists found out that the most noticeable was a sign on a yellow background.
Any speculation behind the three 60-degree arcs is merely speculation, but the ambiguity of its graphic form seems to reflect the mysterious nature of the effects of radiation. The yellow sign of radiation is more abstract than a simple skull and crossbones, but no less sinister.
Ionizing and non-ionizing radiation
Ionizing radiation is radiation with sufficient energy, so that during interaction with an atom it can remove tightly bound electrons from the orbits of an atom, causing the atom to charge or ionize.
Non-ionizing - radiation in parts of the electromagnetic spectrum, where there is not enough energy for ionization.It includes electric and magnetic fields, radio waves, microwaves, infrared, ultraviolet and visible radiation.
Electromagnetic radiation forms
The forms of electromagnetic radiation differ only in frequency and wavelength:
- heat waves;
- radio waves;
- infrared light;
- visible light;
- ultraviolet radiation;
- gamma radiation.
Longer and lower frequency waves have less energy than shorter waves and higher frequency waves (X and gamma rays). Not all electromagnetic (EM) radiation ionizes. Only the high-frequency part of the electromagnetic spectrum, which includes x-rays and gamma rays, is ionized.
Ionizing radiation sign
In 2007, the IAEA and the International Organization for Standardization (ISO), to help reduce unnecessary mortality and serious injury from accidental exposure to large radioactive sources, introduced a new sign of radiation. Now it shows radiating waves, a skull, crossbones and a running man.
It denotes ionizing radiation and complements the traditional international sign "Caution, radiation!" The trefoil, in turn, has no intuitive value and is little known to people, except those who received education in this field.For example, children do not know what the sign of radiation looks like. They perceive the trefoil as a propeller, not understanding the danger that threatens them.
The radiation sign depicted in the photo is intended to warn anyone, anywhere, of the potential danger from approaching the source of ionizing radiation.
The new symbol has been tested with different groups of people. It was shown to people of all ages, with different backgrounds. A photo of a sign of radiation was shown to men and women to make sure that its meaning - “the danger - to stay away” is absolutely clear and understandable for everyone.
So. The new sign of radiation, developed by human factors experts, graphic artists and radiation protection experts, was tested by the Gallup Institute with a total of 1,650 participants from different countries around the world.
Placing a new mark
The symbol is intended for IAEA category 1, 2, and 3 sources, which are identified as dangerous sources that could cause death or serious injury, including food irradiators, teletherapy devices for cancer treatment and industrial radiographic devices.
The symbol is placed on the device where the source is located, as a warning that the device cannot be dismantled or approached. It will not be visible during normal use, only if someone tries to disassemble the device. The symbol is also not possible to find on the doors of the building, on transport bags or containers.