Radioactive fallout in air and rain

Samples of atmospheric particulate and rainwater have been collected from the United Kingdom and elsewhere. Results are presented of analyses of these samples for various fission products and certain other radionuclides. Concentrations of caesium-137 in air in the United Kingdom in 1988 were mainly attributable to the resuspension of deposited activity resulting from the Chernobyl accident of April 1986 and were less than 1% of those averaged in 1986 although there is also some evidence of Chernobyl materials from the stratosphere. Plutonium concentrations in air and rainwater were a very small fraction of the NRPB's Generalised Derived Limit for members of the public. Estimates are given of the worldwide deposit of Cs-137 and Sr-90 to the end of 1988. The gamma and beta-ray dose rates from fallout at Chilton are estimated from the observed deposition. (author)