The first-ever cooperation meeting between national dosimetry laboratories in Latin American and Caribbean countries has set the ground for better radiation protection of patients and workers in the region. The IAEA-led meeting, which took place in Recife, Brazil earlier this year, stimulated the development of national strategies and knowledge sharing among experts from 26 institutions in 20 countries.
Dosimetry is the science of measuring radiation doses, which is crucial for protecting workers who use radiation in industry or medicine and patients who are exposed to it through medical imaging, nuclear medicine or radiotherapy. Too little radiation can be ineffective, while too much can be harmful.
To determine the right dose, experts measure radiation with calibrated dosimeters. But to measure a dose correctly, they must also ensure that these dosimeters are accurate and have been adequately calibrated. This is what dosimetry is all about.
“In Paraguay, we are seeing a rise of patients benefiting especially from the curative powers of radiation in the medical sector. Making sure that we are using the right doses is key,” said Oscar Bordón, from the National Customs Administration in Paraguay, who participated in the meeting in Recife. “But there is no metrology without calibration and comparison. We can measure the doses, but how can we guarantee that what we are measuring is correct, if we do not have anything to compare it to?”
Calibrations are provided by Secondary Standards Dosimetry Laboratories (SSDLs) in many countries. But Paraguay is an example of a country which does not have an SSDL. While currently experts are sending dosimeters to Argentina, Brazil or Cuba for calibration, the authorities in Paraguay are planning to establish their own SSDL.
The idea behind the meeting was to assess the status of SSDLs in the region, identify gaps and needs, and strengthen cooperation among laboratories, said Nicola Schloegl, manager of this technical cooperation project at the IAEA.
“It is through encounters like these that we discover that we are not alone, that other colleagues in other countries have similar problems,” said Guillermo Balay, in charge of Uruguay’s SSDL. During the meeting, Balay found that some experts were interested in Uruguay’s way of measuring doses from cobalt-60 irradiators and in medical imaging, methods that he is now sharing with them. Similarly, he learnt about some Brazil’s efficient and low-cost solutions to guide and protect cablings used for measuring radiation with cesium-137 sources, which he will apply in his SSDL.
Experts working in laboratories in Argentina, Bolivia, Brazil, Chile, Colombia, Costa Rica, Cuba, the Dominican Republic, Ecuador, El Salvador, Guatemala, Honduras, Mexico, Nicaragua, Panama, Paraguay, Peru, Uruguay and Venezuela attended the meeting in Recife. They were supported by experts from the National Physical Laboratory, a Primary Standards Dosimetry Laboratory (PSDL) in the United Kingdom, where the quantities used to measure radiation doses are established (see Connecting Labs).
With the support of the Department of Nuclear Energy of the Federal University of Pernambuco, Brazil, a comparison exercise was initiated at the meeting. Each participant received a dosimeter to irradiate in their SSDL with a specific dose, which they would send back to the Metrology Laboratory of Ionizing Radiation in Recife. Currently, they are verifying that all measuring capacities are comparable and in line with acceptance limits.
Similar exercises are planned in Asia, Africa and Russian speaking countries, said Paula Toroi, medical radiation physicist and SSDL Officer at the IAEA.
There is no metrology without calibration and comparison. We can measure the doses, but how can we guarantee that what we are measuring is correct, if we do not have anything to compare it to?
