Scattered radiation reaching doors and windows of diagnostic X-ray rooms.

Abstract

Areas adjacent to diagnostic X-ray departments may need to be identified as Controlled or Supervised Areas under the Ionising Radiations Regulations 1985. To assist in identifying such areas in hospitals in two Scottish Areas (Lothian and Fife), dose monitors have been placed in various sites in diagnostic X-ray rooms for at least 6 months of 1985. The sites chosen were mainly (a) X-ray room windows to areas which could be occupied, such as car parks and gardens, and (b) Xray room doors having no lead (or an uncertain quantity) and opening onto corridors, circulating areas or waiting areas. All sites chosen received scattered radiation only, except for two which were behind chest stands. Fifty-seven sites were monitored in 30 X-ray rooms in 17 different hospitals. The majority of the rooms were general-purpose, but a number of more specialised rooms were included. The hospitals ranged from a large teaching hospital to small local hospitals and clinics, and are believed to represent a reasonable sample of current UK usage and practice. A classification of the rooms and sites is given in Table I. The dose monitors were film badges supplied and assessed by the National Radiological Protection Board (NRPB). They were exposed in ordinary holders and changed every 4 weeks for at least six periods. Some sites gave consistent results from period to period (e.g. five periods giving 0.4 mSv and one giving 0.3 mSv), while others fluctuated rather more.