Dosimetry Review: 20 Years of Alpha Dosimetry in the Canadian Uranium Mining Industry
B. Bjorndal, R. Moridi
It is now well known the health risks associated with exposure to radon progeny (RnP) and to long-lived radioactive dust (LLRD) in the uranium mining industry. For over a century, higher incidences of lung cancer have been observed in uranium miners from Canada and around the world. Many of the miners working in early uranium mines were unknowingly exposed to high concentrations of RnP and LLRD. Inadequate engineering and radiation protection combined, with a lack of understanding of health risks of radiation exposure were core reasons for the high doses routinely received by miners. In Ontario in the 1950's and 60's, the average annual RnP exposure to uranium miners was estimated to be approximately 10 WLM (BEIR VI 1999). At Beaverlodge, Saskatchewan, which operated between 1949 and 1982, the average annual RnP exposure was estimated to be approximately 13 WLM (BEIR VI 1999). Average annual RnP exposures in excess of 100 WLM have been estimated for workers at Port Radium in the North West Territories between 1930 and 1960 (BEIR VI 1999). Often, formal dosimetry programs were not implemented until several years after the start of commercial operation. When implemented, exposure estimates were confined to RnP and did not include exposure from inhalation for LLRD. Many hard lessons were learned in the early years of uranium mining, particularly the need for adequate radiation protection of workers.
This abstract was presented at the 35th Annual Midyear Meeting, "Decommissioning and Environmental Restoration", Controlling Dose I Session, 2/17/2002 - 2/20/2002, held in Orlando, FL.