USING GAMMA-RAY SPECTROSCOPY FOR THE STUDY OF CHERNOBYL FALLOUT ON EDIBLE MUSHROOMS

Gamma-ray spectroscopy has been widely used in many areas of applied s cience. We have used the method to compare the Cs-137 contamination in fungi collected in central Sweden, Ukraine (Kiev region) and southern Ontario, Canada. Mean activities were comparable for Sweden and Ukrai ne, but were much lower in the North American samples. Many European m ushroom species which are considered as prized edibles, contained unac ceptably high levels of Cs-137 (1 kBq/kg) and should not be sold for h uman consumption. By contrast, no activity in mushrooms collected in O ntario or northern Michigan exceed 1 kBq/kg. The excessive contaminati on in European mushrooms is primarily due to the Chernobyl reactor acc ident of 1986. However, our observations suggest that about 20% of the Cs-137 contamination in the Ukraine is not due to this accident.