Airborne Radionuclide Concentrations (ARC) Dataset Guide The Airborne Radionuclide Concentrations (ARC) dataset is a collection of airborne radioactivity concentration measurements created and maintained by Health Canada’s Radiation Protection Bureau (RPB). It consists primarily of aerosol particulate and noble gas measurements from RPB’s monitoring networks including the Comprehensive Nuclear Test- Ban Treaty (CTBT) stations and Laboratories and the Canadian Radiological Monitoring Network (CRMN). Additionally, data from other sample sources, such as field samples from mobile radiation monitoring systems or samples collected and measured by other organizations but analyzed at RPB can be archived to the dataset. The dataset is updated on a regular basis and has open access to the public. RPB is responsible for delivering Health Canada’s program in ionizing radiation protection and in nuclear non-proliferation and disarmament. By monitoring radiation and radioactivity in natural environments, RPB detects natural background radiation, nuclear/radiological accidents, and nuclear weapon tests to investigate risks to the health and security of Canadians. Information about the dataset The two major sample types reported in the ARC dataset are particulate air filter samples and noble gas samples from RPB’s monitoring stations. The particulate samples are collected by drawing air through a filter paper which traps the aerosol particles. Sampling is typically performed on a daily, 3-day, or weekly schedule. The filters are then prepared in a specific dimension and shape for subsequent measurement. Noble gas samples are collected by pumping air into a separation system where the desired gas (for example, the noble gas xenon) is isolated and collected for measurement automatically. The sampling periods are typically 8 hours, 12 hours or 24 hours. All reported sample results are from measurement spectra analyzed at RPB. The analysis results are the identification of radionuclides observed and their activity concentration in air (in Bq/m3). For particulate air filter samples, the naturally occurring radionuclides, beryllium-7 (7Be) and lead-210 (210Pb) are normally observed. 7Be is a natural cosmogenic radionuclide that is produced in the upper atmosphere when cosmic rays break oxygen and nitrogen atoms into fragments of lower mass in a process called spallation. 210Pb is a natural radioisotope from the decay of radon (222Rn), radon being a radioactive gas in nature that emanates from the ground and is present in the air. Some anthropogenic (originating from human activity) radionuclides are occasionally observed. Cesium-134 (134Cs), cesium-137 (137Cs), and iodine-131 (131I) are typical examples of those anthropogenic radionuclides. Occasional presence of these radionuclides for short periods and at low activity concentrations do not result in a significant radiation exposure relative to natural background and therefore do not typically represent a direct health concern to people. For the noble gas samples, the following four radioactive xenon isotopes are analyzed: 133Xe, 131mXe, 133mXe and 135Xe. Their activity concentrations are reported whenever the isotopes are detected. These isotopes may originate from medical isotope production facilities, nuclear power plants, research reactors and the use of the medical isotopes but may also be emissions of a declared or clandestine nuclear explosion test. The structure of the IRIX XML data file The ARC dataset is created as an XML file that conforms to the International Atomic Energy Agency’s (IAEA) International Radiological Information Exchange (IRIX) Format. The IRIX format is the recommended standard by IAEA to exchange information among organizations and countries during a nuclear emergency or a radiological incident, as well as in normal operational conditions ^Footnote 1 <#fn1> ,^Footnote 2 <#fn2> . It is machine and human readable, and can be quickly processed, summarized and shared. The information in an IRIX report is organized into sections, such as Release information section, Measurement section, and Location section etc. More information about the IRIX format can be found on the dedicated website ^Footnote 3 <#fn3> . The ARC dataset not only provides the radionuclide activity concentrations but also the sample related information. Under normal monitoring operation, the report usually contains only Identification, Measurements, and Location sections. However, it is expandable to include more sections as needed. The Identification section contains information about the report such as the name of the organisation issuing the report and the date and time when the report was created. The Measurements section is the main entry of each data file and exclusively for reporting data derived from actual measurements. This section has two subsections, Dose Rate () and Sample (), to store gamma dose rates and nuclide concentrations respectively. The ARC dataset only uses subsection. Each section represents one sample and has a set of elements to describe sample related information, its measurement and analysis results. The sample related information is contained in elements such as: , and . The measurement and analysis results of the sample are contained in the element under the section. Each element represents one measurement and has one or multiple sub- elements. Every element represents one observed radionuclide and contains information such as measuring period, nuclide name and concentration. A element with value as “Sample” represent each sample measured. This will include samples that were taken, measured and analyzed regardless if any nuclides were observed and to facilitate descriptive reviews of all samples measured in the dataset. The last part of the dataset is the Location section which has the information of all monitoring stations. How to open/view the data file The data file can be viewed in one of the following two ways: 1. Open the data file in any web browser as an XML file. First find the XML file you want to open, then right-click the file and select “Open with” and select a web browser from the list of programs, the file will be opened in the browser as a text file, and your browser will automatically indent nested tags. Alternatively, you can double click the XML file and open it in your default web browser. 2. The data file can also be opened in Excel as an XML table. 3. Run Excel first 4. Use “File->Open” menu and select the data file 5. In the “Open XML” window, select “As an XML table” option (You will be informed that the XML file does not refer to a schema) 6. Click “OK” (Excel will construct a schema for you based on the tags in the file), and the XML file will be opened with a table format References Footnote 1 Guidelines on the Harmonization of Response and Assistance Capabilities for a Nuclear or Radiological Emergency (EPR-Harmonized Assistance Capabilities 2017) International Atomic Energy Agency, Vienna, 2017. Return to footnote 1referrer <#fn1-rf> Footnote 2 Application of International Radiological Information Exchange (IRIX) standards for radiation monitoring data report. Sanjoy Mukhopadhyay; Florian Baciu; Gurdeep Saluja; Jose Segarra; Franck Albinet Proc. SPIE 10763, Radiation Detectors in Medicine, Industry and National Security XIX, 1076308 (11 September 2018); DOI: 10.1117/12.2309380. Return to footnote 2referrer <#fn2-rf> Footnote 3 International Atomic Energy Agency, International Radiological Information Exchange (IRIX) Format – Reference Description IRIX Version 1.0.https://www.iaea.org/publications/12257/international- radiological-information-exchange-irix-format Return to footnote 3referrer <#fn3-rf>