The Canadian Radiological Monitoring Network – Airborne Radioactivity

This dataset provides the results obtained by Health Canada’s Radiological Monitoring Network (CRMN) for airborne radioactivity content at monitoring stations across Canada. More information about the CRMN network can be found here: The results provided are activity concentration, uncertainty and the minimum detectable concentration for the naturally occurring radionuclides, beryllium-7 (7Be) and lead-210 (210Pb), and the anthropogenic (originating from human activity) radionuclides, cesium-134 (134Cs), cesium-137 (137Cs), and iodine-131 (131I). The data comes from the analysis of particulates accumulated in filter media, drawn by high-volume air samplers fixed in the field. Such data is typically dominated by natural radionuclides, such as 7Be and 210Pb. 7Be is a natural cosmogenic radionuclide that is produced in the upper atmosphere when cosmic rays bombard oxygen and nitrogen. 210Pb is also a natural radioisotope that results from the decay of uranium (238U) naturally present in the ground. An important intermediate step of uranium decay is radon. Radon is a naturally occurring radioactive gas that moves through the soil and becomes diluted when mixed with outdoor air. Radon represents close to 50% of radioactivity exposure for most Canadians because it can accumulate in indoor environments, sometimes to high levels. 210Pb is present in the CRMN air filters because radon eventually decays to 210Pb, with several intermediate steps. More information about Health Canada’s National Radon Program can be found here: For all our stations, the airborne radioactivity data shows a small increase in the activity concentration of 134Cs, 137Cs and 131I measured between March and May of 2011, attributable to the nuclear accident at the Fukushima-Daiichi Nuclear Power Station. It is important to note that, even at their respective peaks, the measured activity concentrations of 134Cs, 137Cs and 131I represent only a small fraction of typical background exposure from natural sources of radiation. Occasionally, other small increases in activity concentration of anthropogenic radionuclides are observed. Spikes in 137Cs activity are often associated with forest fires, which can lead to the re-suspension of 137Cs already present in the environment, most likely from atmospheric nuclear testing in the 1960’s. Detection of small amounts of 131I is commonly associated with its medical use by hospitals.


Resource Name Resource Type Format Language Links
The Canadian Radiological Monitoring Network - Airborne Radioactivity Dataset CSV English
Airborne Radioactivity - Graphs Guide PDF English Access
Airborne Radioactivity - Graphs Guide PDF French Access
Airborne Radioactivity - data dictionary Guide PDF English Access
Airborne Radioactivity - data dictionary Guide PDF French Access


  • Patrick Paradis


    CRMN : Can't acces any data on research done for 2011 to 2014 and 2015. All is hidden away for what purpuse? We need to see graphs , where and at wich conditions those samples were taken . Its imperative that the CRMN give all its data to all Canadians on: Air Particulate Precipitate External Gamma Dose Atmospheric Water Vapour Milk Samples Drinking Water Samples Measurement of Food Samples Export Certification Seen ppl with geiger counters all over Canada on youtube with 216 cpm in the rain and yet nothing.... nothing from the CRMN... Link on your webpages all studies done since the first year of existence of the CRMN, we pay taxes and your jobs so give us the information: clear info not invalid links. Like I said I've seen 216 cpm (100cpm= quarantine) near Québec city ain't a scam , I demand a better CRMN site than can give results to the population of Canada. If you care for Canadians for your brothers ans sisters give us the data. Go public! This is a formal complaint done to the Governement of Canada, to the CRMN and to Health Canada, tell us the truth! Send all info in regard to the CRMN studies from 2011 to may 2015 please.

  • open-ouvert


    Thank you for your comment. The following response has been posted on behalf of the data owner : "Health Canada is fully committed to providing all of our Radiological Monitoring Network data to the public. This page contains the airborne radioactivity content at monitoring stations across Canada along with the associated graphs. By selecting the "Canadian Radiological Monitoring Network" tag above, you will be able to browse our other data sets. These include the data sets you have requested, as well our data on fish samples tested for radioactivity. We will be updating this page twice a year. Additionally, our radiation monitoring data from our fixed point surveillance network is updated four times annually and can be found here:" If you would like more detailed information on our programs, or would like to receive the requested data sets directly, please contact us at "