Chernobyl--the radiological impact on Canada.

On 26 April 1986, an accident at a Ukrainian nuclear reactor at Chernobyl triggered the release of large quantities of fission products into the atmosphere. After 7 May 1986 measurable quantities of ruthenium-103, iodine-131, cesium-134, and cesium-137 were detected in environmental sampling carried out in all regions of Canada. Maximum airborne concentrations for each radionuclide were of the order of a few mBq.m-3 and contaminated milk samples on average contained less than 1Bq.L-1 of iodine-131 and cesium-137. The mean value of the effective dose equivalent for an adult Canadian in the two months following the accident is calculated to be 0.28 microSv. As this total radiation dose is about 10(-33) of the dose from natural background during the same period, the resultant radiological detriment is concluded to be negligible.