§ Mr. Frank Cook
asked the Paymaster General if he will take steps to ensure that a dose of 500 mSv. to the lungs, breast, red bone marrow or gonads is not received by workers.
§ Mr. Trippier
The Ionising Radiations Regulations 1985 specify a dose limit in terms of effective dose116W equivalent for the whole body of 50 mSvy -1 and a dose limit for individual organs in terms of dose equivalent of 500 mSvy -1.
Both requirements must be met. In practice, one or other will be limiting; whichever limit is achieved first will set the ceiling. In the case of irradiation of lungs, breast, bone marrow or gonads singly, the overriding limit will be the whole body effective dose equivalent limit of 50 mSv which will be reached before the individual organs mentioned receive 500 mSv.