- CT scans, used increasingly in hospital on children with
head injuries, may damage their intellectual development, according to
new research on the effects of low doses of ionising radiation on the brain.
-
- Studies of those who were exposed to radiation while
still in the womb from the atomic bombs dropped on Nagasaki and Hiroshima
have shown that high doses can harm the brain. But little is known about
the effects of low doses according to Per Hall, an associate professor
at the Karolinska Institute in Stockholm, and colleagues writing in this
week's British Medical Journal.
-
- Professor Hall and his team followed up 3,094 men who
had received low dose ionising radiation to their head as treatment for
birthmarks, such as port wine stains, when they were less than 18 months
old. Some received more than one treatment.
-
- All Swedish men undergo cognitive and psychological tests
when they are 18 before military service.
-
- These results and other information, such as education
and the father's occupation, which gives a rough guide to socio-economic
status, were used to compare the intellectual abilities of men who had
received different doses of radiation to different parts of the brain.
-
- They found that low doses of ionising radiation, similar
to those from a CT scan, "may adversely affect intellectual development".
The numbers of those going on to high school, and their scores in cognitive
ability tests, decreased as the dose of radiation to which they had been
exposed as babies increased. The men were all born between 1939 and 1959.
At the time in question academic performance was the main criterion for
high school entrance in Sweden.
-
- The use of CT scans in hospitals to assess the extent
of brain injuries in children who have been in accidents needs to be reassessed,
the researchers say.
-
- It is possible that some young patients are receiving
a dose of radiation which will permanently affect their intellectual development.
-
- CT scans are not routinely recommended for children,
but they are often used.
-
- Guardian Unlimited © Guardian Newspapers Limited
2004
|
