Zircon Industry Association, 24 Old Bond Street, Mayfair, London W1S 4AP, UK
Used in countless everyday products, zircon is an essential component of our modern world. Zircon and its derivatives, zirconia and zirconium, are used in a wide and diverse range of domestic and industrial applications. For example, ceramic tiles and sanitaryware in many buildings and bathrooms contain a small amount of zircon to increase their resilience, whiteness and brightness. Zirconia plays a key role in daily life, in uses like biomedical and dental implants, as well as in critical industrial applications such as oxygen sensors and refractory materials. While cubic zirconia gemstones, more commonly known as synthetic diamonds, offer a more affordable option for jewellery items.
As a natural mineral, zirconium silicate (zircon) is mined from the earth’s crust and, like many rocks and minerals, zircon contains low levels of uranium and thorium atoms locked inside its crystal structure. Such minerals are called ‘naturally-occurring radioactive materials’ (NORM).
Zircon has been present in the earth’s crust since its formation some 4.5 billion years ago. Interestingly, the NORM property of zircon is very useful. For example, zircon plays an important role in radiometric dating of ancient rocks as the entrapped uranium acts as a reliable clock within the zircon, making it possible to accurately date rocks that were formed in the earliest period of earth’s history
Therefore, zircon is radioactive; however, radiation levels from zircon are low, similar to that of other naturally-occurring sources such as granite (often used for worktops) and are not significantly greater than background levels normally found in the environment.
When used in everyday products such as ceramic tiles, the amount of radiation emitted is equally very low and well below what is considered to be acceptable safe levels. To put this into context, you would be exposed to a higher dose of radiation if you had a chest x-ray or took a long-haul flight. So, while zircon is a NORM, it poses no risk to public health.
Precautions are taken in industry to protect those workers processing large quantities of zircon. Whilst exposure to radiation remains low, those that work regularly with zircon are advised to take some simple health and safety measures to further protect themselves. These are outlined in the recently published ZIA guidance 'Working safely with zircon sand'.
Zirconia (zirconium dioxide) and zirconium metal, which are made from zircon, are not radioactive. The processes involved in manufacturing these products breaks open the zircon crystal structure and removes the uranium and thorium atoms. So, there are no radioactive traces in items like dental implants, biomedical implants and jewellery made from cubic zirconia.