Resuspension following Chernobyl

Since the Chernobyl accident, concentrations of 137Cs at many locations in Europe have remained elevated in comparison with the declining values expected from nuclear weapons fallout. Long term mean concentrations correlate with local depositions of Chernobyl material, and there can be little doubt that they predominantly are due to resuspension. Since information on resuspension in European conditions is sparse, this opportunity to observe resuspension from an extensive contaminated area in field conditions is valuable. The data show that the air concentration due to resuspension has declined progressively with time at all sampling sites. The resuspension factor is systematically higher at sites where the initial deposit of 137Cs from Chernobyl was low, and this feature of the data is probably attributable to long range transport of resuspended activity over Europe. At some sites there is evidence for increased resuspension due to road traffic. Some models proposed for predicting the effects of resuspension have been compared with the data. Generally agreement is closer with the models that predict lower resuspension rates. High rates of deposition of resuspended 137Cs have been observed at some sites: this probably involves material of very local origin