Behind the ion curtain

The National Radiological Protection Board has published a review (its fifth) of annual exposure of the UK population from all sources of radiation exposure - including occupational. The report compares 1991 data with that from 1987, a period during which UK population increased from 56.9 to 57.6 million. The annual collective dose is 150,000 man Sv, with the average dose about 2.6 millisieverts (mSv). The most significant source of radiation is radon, with exposure of patients to X-rays next. Doses from nuclear discharge are trivial for most people. Radioactive fallout from nuclear weapons testing between the 1950s and the 1970s is still found, but at very low and declining levels. Radiation following the Chernobyl disaster is now at very low levels in foodstuffs, although it persists in some upland areas. (author)