When the nature of radioactive material was first discovered and investigated, it was some time before it became apparent that radiation could exert harmful effects on living tissue. Once confirmed, it was soon learnt that these energetic emissions could be blocked by heavy metals and concrete. While such materials provided the necessary protection, their lack of transparency made working with radioactive materials unduly difficult, initiating a quest to develop an alternative material able to transmit visible light, but blocking the harmful rays. The result was X-ray shielding glass made impervious to ionising radiation by the inclusion of lead and, in time, mixtures containing other heavy metals.
This created the prospect of more practical roles for so-called Röntgen rays, the first being their use as a diagnostic tool to locate and produce images of fractures and foreign bodies. Later, with the aid of sophisticated computer algorithms, it became possible to generate 3D images of an entire body, section by section, using the technique known as computerised axial tomography – the CAT scan. Given the effect of various forms of ionising radiation on living cells, their use in the destruction of abnormal cell growth was a logical step. Without X-ray glass to shield the operator, radiotherapy, CAT scans, mammography, magnetic resonance imaging (MRI), and routine screening for pulmonary TB could not be safely undertaken.
Apart from aiding these crucial medical applications, there are now many additional uses for x-ray shielding glass both in the world of research and in industry. In the laboratory, technicians are often required to handle radioactive isotopes and would be unable to do so without remote manipulation equipment and the unobstructed but protected view provided by cabinets fitted with X-ray glass panes.
On a smaller scale, but no less important to safety, x-ray shielding glass is used to manufacture the lenses for safety goggles, electron beam systems, and plasma generators. To ensure the safety of the crew and passengers, before being loaded on to the aircraft, all items of luggage are now subjected to a small dose of radiation in order to assess its contents. To protect the airport security staff responsible for the screening once again requires the use of X-ray glass.
Certain foodstuffs, as well as disposable items, often need to be sterilised. In some cases, conventional methods using heat or chemicals may harm a product and so an alternative method will be required. While ultraviolet irradiation may be adequate for some items, others may need the more robust action of gamma rays. Again, protection is vital for the workers and, most often, it is the German manufacturer Schott that offers the solution with its world-class X-ray glass shielding.