Radiological classification of Polish underground mines and recommendations of surveillance.

The paper presents the most recent data, collected 1987-1989, on concentrations of 222Rn products in the air of all Polish underground non-uranium mines, and data on the exposure of the miners employed there. The concentrations and exposure of miners were evaluated by using 'passive' dosimeters, based on the track-etch solid state nuclear track detector, worn as small individual cassettes on helmets of representative groups in every mine for one month, four times a year (once in each season of the year). The paper contains the average annual exposure of miners in coal-, metal-ore-, and chemical raw materials oremines. The paper, also presents expected 'frequency' distributions of individual miners' exposure in particular types of mines, as well as the computer simulations of 'relative frequency' distributions of expected miner's exposure when the Annual Limit of Exposure would be adopted at the level 17, 12, 8.6, 6.9 and 3.4.10(-3) Jhm-3 (5.0, 3.5, 2.5, 2 and 1 WLM). The concept and criteria of classification of mines according to the radiation hazards are presented and discussed. According to that concept, all mines in Poland have been considered and classified into four classes of mines with a different level of radiation hazard. The appropriate radiological surveillance to the respective class of mine is proposed and discussed.