The CCRI News resource

At first sight, the theme for World Metrology Day 2024 – Sustainability – does not seem to have much overlap with the activities of primary and secondary standard dosimetry laboratories. However, when one considers the meaning of sustainability in the light of the 17 UN Sustainability Goals it becomes more obvious that ionizing radiation is very relevant to the subject and, by inference, ionizing radiation metrology has an important role to play in supporting (and sustaining) various applications. Here are just a few examples.

First of all, ionizing radiation metrology contributes to “Ensure healthy lives and promote well-being for all at all ages”. Ionizing radiation is one of mankind's main tools in the fight against cancer, with radiation therapy treatments becoming increasingly varied (both in terms of beams and methods) and tailored to the biological specificities of each individual. The increasing cancer burden, identified by the IAEA more than a decade ago, has driven the increased use of radiation-based diagnostic procedures, and NMIs/DIs have responded by the development of novel systems for the accurate comparison of national standards for radiotherapy, brachytherapy, mammography and other x-ray imaging approaches. There is now strong clinical evidence that proton therapy has significant benefits in treating pediatric cancers and CCRI Section I has initiated discussions around the need for international comparisons of proton dosimetry standards. To exploit all the benefits of proton therapy, the effects of unwanted dose due to secondary high energy neutron radiation needs to be investigated. CCRI Section III has recently convened a task group to investigate how high-energy neutron beams suitable for metrological applications can be produced and how the community can come together to use them in an efficient and sustainable manner. Ultra-high dose rate (FLASH) therapy is attracting significant attention and multiple research groups are investigating the technology required to accurately measure and deliver these almost-instantaneous treatments. Perhaps the most disruptive, and exciting, treatment technique is radiopharmaceutical therapy (RPT), and CCRI Section II has been leading an international effort to develop normative standards for clinical implementation as well as co-ordinate the necessary research into standardizing the various radioisotopes being investigated for RPT, highlighted by a recent workshop on alpha-particle therapy (02/2024).

Ionizing radiations can also help to “Take urgent action to combat climate change and its impact”. Within the context of global commitments to reduce greenhouse gases (GHGs), there is the requirement to accurately measure CO2 and CH4 emissions from different sources. The radioactive signature from C-14 can be used as part of this monitoring system. Other radioisotopes, like Be-7 and Na-22, produced by cosmic radiations in the atmosphere could also be useful tools to better understand key atmospheric processes and help to obtain more accurate prediction of global warming. CCRI(II) has put several of these radioisotopes, and in particular C-14, on the priority list for the upcoming activity comparisons with the new reference system (the extended SIR or ESIR) maintained by the BIPM and has started discussions among various specialists in this field to better match the needs pointed out at the last BIPM-WHO Metrology for climate action workshop (09/2022).

In addition, ionizing radiations contribute to ensuring “Availability and sustainable management of water and sanitation for all”. A range of radiation beams – primarily Co-60 and high-energy electrons – have been used for decades for the sterilization of single-use medical goods. The same techniques can also be applied to food, water and waste treatments to eliminate pathogens and certain chemical contaminants. In the field of high-dose dosimetry, CCRI partners with the ASTM international E61 committee, which is the primary forum worldwide for radiation processing standards.

Ionizing radiation metrology is also deeply involved in “Ensuring access to affordable, reliable, sustainable and modern energy for all”. The decarbonization of energy production will require multiple technologies but at least in the shorter-term, fission-based nuclear power will be crucial for many countries. The safe operation of such nuclear facilities requires accurate radiation protection measurements and the calibration services that NMIs/DIs provide support the delivery of sustainable and affordable energy while assuring minimal environmental impact, e.g., through the measurement of radionuclides in natural matrices. Looking further into the future, small and new generation fission reactors as well as fusion technology have the potential to offer a significant resource for energy production. All will need more accurate nuclear data (nuclear decay, neutron cross-sections, etc.) with several challenges for ionizing radiation metrology. For example, the mechanisms of fusion are sufficiently different from fission that new facilities will be necessary to produce the reference neutron beams needed for metrological support.

 “Build resilient infrastructure, promote inclusive and sustainable industrialization and foster innovation” is also part of the missions of the ionizing radiation metrology. Metrology can indeed be viewed as the quantification of knowledge, and various leaders since the industrial revolution have espoused the value of that quantification. The techniques that NMIs/DIs develop to accurately measure ionizing radiation are focussed on industry/societal needs and therefore are directly relevant to this goal. In addition, we have a responsibility as an ionizing radiation metrology community for personal sustainability, and therefore CCRI is active in reviewing how we can operate more efficiently, e.g., through simpler comparison protocols and CMC reviews, partnering with collaborators to make better use of radiation facilities, and continuing to engage with end-users to ensure the rapid and accurate transfer of knowledge and technology.

For more details on CCRI activities see https://www.bipm.org/en/committees/cc/ccri.

Article written for the SSDL Newsletter No. 79, May 2024