[Assessment of radiation exposure of miners to radon and its daughter products in selected non-ferrous metal mines].

BACKGROUND

For over 40 years already, the Nofer Institute of Occupational Medicine (NIOM) in Lodz has been supervising non-ferrous metal mines for miners' radiation risk of radon and its short-lived daughters products found in the air of mines.

MATERIAL AND METHOD

The supervision involves the use of trace detectors placed in passive dosemeters worn by a representative group of miners.

RESULTS

During the late 1960s, the exposure in some mines was as high as 50 mSv/year. Owing to the steps undertaken in the mines, including primarily the provision of improved ventilation systems, the exposure was reduced to 5 mSv/year, and then to 2 mSv/year during the 1980s and 1990s.

CONCLUSION

The results of measurements, performed during the recent 10 years, show that the exposure in non-ferrous metal mines is now within the limits specified for worker category B, i.e., not exceeding 6 mSv/year. The mean annual effective dose for a ten-year (1998-2009) period was 2.1 +/- 0.9 mSv/year.