Personal monitoring of workers in irish workplaces

Since 1994 the Radiological Protection Institute of Ireland has been conducting a pilot programme ofpersonal monitoring of workers in workplaces with high radon concentrations. Initially theprogramme involved staff employed by the operators of commercial show caves, but in January 1999it was extended to incorporate non-show cave workers when employees in aboveground offices in twosmall Departments in an Irish University were included.Personal monitoring of show cave staff confirmed the fact that employees in two caves receivedannual radiation doses in excess of 4 mSv. This dose corresponds to exposure at the proposedReference Level of 400 Bq m-3 averaged over a 2000 hour working year. Individual doses to showcave staff ranged from 0.1 mSv to 18.3 mSv per year. During the 5-year monitoring programme 27show cave employees received annual effective doses in excess of 4 mSv. In this 5-year period 11employees worked during more than one operating season and individual cumulative doses rangedfrom 2 mSv to 26.2 mSvPreliminary results are available for the personal monitoring of University staff. Estimated effectivedoses to staff ranged from 0.1 to 1.9 mSv over a 7 - 8 week measurement period.This work demonstrates that personal monitoring of staff using passive radon detectors is a practicaland appropriate measurement technique when it comes to assessing compliance with national radonstandards in underground work environments. The practicality or otherwise of this technique inordinary above ground workplaces is still being assessed.