The forecasts made 10 years ago by a geneticist working in Edinburgh, on the evidence then available, are now regarded as having over-estimated the risk of genetic damage from fall-out radiation. A recent report by the United Nations Scientific Committee on the Effects of Atomic Radiation tentatively estimates that among the children of those exposed to fall-out, up to two in every million live births may suffer some degree of genetic abnormality, ranging from the slight to the serious.