Researchers are claiming that the Chernobyl nuclear accident of 1986 impaired the mental development of Swedish children that were in the womb at the time of the incident. The study analysed the academic results of more than half a million Swedish children. This report from Neil Bowdler:

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Results were the weakest among those children who were foetuses between eight and twenty-five weeks at the time of the explosion. This period, the researchers argue, is the peak period of brain development in the unborn child when brain cells may be at their most susceptible to low radiation. Children born in regions of Sweden which received the most fallout from Chernobyl were also seen to fare worse academically.

The results are controversial. Radiation levels recorded at the time of the accident in Sweden were relatively low - about twice the level of natural background radiation - and it's been thought up until now that such levels were not high enough to impair mental development. Responding to the research, David Brenner, a professor of radiation oncology at Columbia University, New York, said further studies of children in adjacent countries were needed to verify the findings.

Neil Bowdler, BBC

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in the womb
unborn

foetuses
unborn human beings or animals whose organs have started to develop

the peak period of
the most important time for

at their most susceptible to
most easily affected, or harmed by

fallout
the radioactive dust in the air after a nuclear explosion or accident

to fare worse academically
to perform worse as a student, to not succeed at school as much as other students

controversial
causing disagreement or different views

to impair mental development
to harm the development of the brain

adjacent countries
countries that share a common border (here, with Sweden)

to verify the findings
to confirm or deny what the researchers are claiming

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