8th Duncan Memorial Lecture. Childhood cancer and nuclear installations

So where are we now? I think the first thing to say is that there is a well-established excess around Sellafield of childhood leukaemia, although excesses around other nuclear sites are of a lower magnitude. The excess near Sellafield is strongly associated with fathers having high exposure to external whole-body penetrating radiation while working at the installation before their child's conception. But is this association pointing towards a causal mechanism? One possibility is genetic damage, but most geneticists and radiobiologists would consider that the levels of occupational exposure, even at Sellafield, are too low for this to be a plausible pathway on current knowledge. This is based to some extent on the lack of any similar effect among children born subsequently to Japanese survivors of the atomic bombs--however, the scenario is somewhat different contrasting a high short-term exposure with a lower long-term exposure. As well, some workers at Sellafield will also be exposed to radionuclides, such as plutonium, which we have not yet been able to analyse for. In addition, there are other exposures in a complex environment which may or may not be relevant. One experimental study in the laboratory using animals supports the idea that a pathway through irradiation of the parents is plausible, although this one result needs replication. Other causes have been suggested for the excess childhood leukaemia levels in particular around nuclear establishments--these include population movement, implicating viruses that have long been considered to be associated with childhood leukaemia, high rates in isolated communities, and also selection of areas for nuclear sites that have a natural propensity to high rates.(ABSTRACT TRUNCATED AT 250 WORDS)