Concentrations of strontium-90 and caesium-137 in milk produced in the Channel Islands

A programme has begun to monitor activity concentrations of strontium-90 and caesium-137 in milk in the Channel Islands. The results from the first year of sampling in Jersey, Guernsey and Alderney are presented and compared with those for Great Britain and Northern Ireland. Measured activity concentrations are close to the values observed in the mainland countries, and are ascribed entirely to the consequences of fallout from weapons testing in the atmosphere. Small differences between results for these small areas and the national averages are attributed to variations in rainfall. When all the major routes of exposure from fallout are considered, the differences in the committed effective dose equivalent become less important, and are trivial when compared to variations in the exposure that results from natural radiation. (author)