Department of Building Materials, Performance and Technology of the NRBI at the end of 2018 began the international Radon Project within the framework of the Horizon 2020 grant No. 792789 of the European Commission (Call: H2020-MSCA-IF-2017, Proposal acronym: RadonACCURACY).
The main goal of the project is the assessment of uncertainty of the determination of the annual average indoor radon (AAIR) concentration by the results of measurements with different duration and the development of reliable criteria for comparing the AAIR and reference levels.
The objectives include:
Objective 1 – definition of the values of the coefficient of temporal radon variation KV(t);
Objective 2 – assessment of the influence of environmental factors on indoor radon behavior and determination the structure and values of the correction factor k.
Radon is an important carcinogenic factor causing lung cancer. To reduce this risk the legislators limit the AAIR in buildings. However, the reliable assessment of AAIR is a problem, because indoor radon has significant temporal (daily, weekly and seasonal) variations. Despite the AAIR is tested in many countries for several decades, none of national regulations (the measurement protocol in USA, ISO and IAEA recommendations), provide an assessment of the AAIR uncertainty depending on the test duration. This allows neither optimizing the test duration, nor correctly comparing the AAIR with reference levels. Thus, the main goal of the project is the assessment of the AAIR uncertainty based on the results of measurements with different duration and the development of reliable criteria for comparing the AAIR and reference levels. To accomplish this goal, we propose to make: (a) preliminary short-term measurements in at least 180 buildings in Haifa (and in Israel) to identify at least 12 experimental rooms with a high radon level, (b) complete annual radon monitoring in these rooms, also measuring the concentration of soil radon and its flow under single building. Based on the original algorithm to process monitoring data, the radon temporal variation coefficient values (depending on the measurement duration) will be obtained and verified. This coefficient is the main source of AAIR uncertainty. In addition, the degree of influence of environmental factors on indoor radon behavior (correction factor) will be determined. Using the correction factor can significantly reduce the AAIR uncertainty. The results of this study will help to: (a) apply in practice the principle of AAIR control firstly proposed by us, (b) revise the international standard (ISO), (c) develop a strategy to identify buildings with high radon, (d) assess the exposure doses from radon and create a map of radon hazard zones in Haifa (and in Israel), (e) develop the career of the researcher.
The study uses a citizen science approach for data collection, in which the public (in this case school students) assist scientists in their research. The project tasks in terms of conducting a mass survey of buildings have been significantly expanded, thanks to the possibility of attracting Israeli schoolchildren. Involving schoolchildren in the measurements of radon in their homes seems to be an effective instrument, since the dwellings to be covered correspond to both conditions (i) the random sampling principle, and (ii) the distribution of measurement points in proportion to the population density. Fulfillment of these conditions ensures the representativeness of the sample of buildings and the reliability of assessing such important parameters as the average dose of the Israeli population due to radon, as well as the proportion of buildings with radon concentrations above the reference level. In addition, older schoolchildren are quite capable to perform a simple procedure for recording test conditions and passive exposure, using simple sensors.
Radon survey in Israel involving schoolchildren was started in January 2019. To implement this project, the following actions were required :
– participation of researchers from the Technion NBRI as project initiators supported by the European Commission in the framework of the “RadonACCURACY” grant,
– participation of the Taking Citizen Science to Schools (TCSS) Center as a communicator between representatives of the educational system and the Technion NBRI team;
– permission from the Israeli Ministry of Education to attend schoolchildren in a survey, subject to the consent of their parents and the protection of personal data,
– creating the “RadonTest” online system for conducting mass measurements of indoor radon based on a special mobile application associated with a laboratory database via a web-site,
– development of miniature charcoal flacons (20 ml) for passive sampling and sticking them with QR-code that is scanned by a mobile phone to access the web-site, and
– logistics support.
Scanning QR codes allows to identify the sample, the geolocation of the test object, the beginning and end of the sampling. In addition to the detailed sampling guide, the mobile application has a questionnaire to collect information about the building characteristics and testing room. Our experience shows that the use of a mobile application is not difficult, even for schoolchildren.Thus, sampling and registration of the test conditions can be successfully performed by the school children themselves, without professionals, after initial guidance by the students’ teachers and the TCSS team. After returning the exposed samples to the Technion NBRI laboratory, the professionals perform their identification and measurement of the radon activity in the charcoal flacons. The measurement results are stored in the database and displayed on the Radon Map .
The “RadonTest” online system can be used in any country and in different laboratories and serve different measurement methods.