Madam, - Cormac O'Raifeartaigh's interesting and informative Irishman's Diary on Pierre and Marie Curie (April 7th) contains two slightly misleading statements.
Firstly, Dr O'Raifeartaigh refers to the discovery that small doses of radiation could cure malignant growths and later to the fact that Pierre and Marie Curie were not aware that large doses of radiation could be dangerous.
What Pierre Curie actually discovered was that large doses of radiation to tumours provided an effective form of treatment. What the Curies, in common with other pioneering users of ionising radiation, did not realise was that relatively small doses of radiation - as well as, of course, large doses - increase the risk of developing cancer.
The risk of cancer induction became clear only later from studies of cancer rates in pioneering radiologists, patients who had been exposed as to radiation as part of their diagnosis or treatment and, in particular, the survivors of the nuclear attacks on Hiroshima and Nagasaki.
The current international radiation protection standards are based on these studies. - Yours, etc,
CHRISTOPHER HONE, Radiological Protection Institute of Ireland, Dublin 14.