Abstract: In 2019-2020,75 non-uranium mines in 11 provinces (autonomous regions) were selected and investigated. Solid State Nuclear Track Detector was used to measure the radon concentration in mines. The arithmetic mean (AM) of radon concentration in metal mines was (1 334 ±3 301)Bq/m³, the geometric mean (GM) of them was (317± 4.6) Bq/m³, ranging from 22 to 28 314 Bq/m³(N = 416). The AM and GM in non-metal mines was (162±151) Bq/m³ and (125±2) Bq/m³, respectively, with range of 22-971 Bq/m³ (N=113). There was 31.8% of the 529 underground measuring points with radon concentration exceeding 300 Bq/m³, 19.8% of measuring points exceeding 1 000 Bq/m³ and 9.3% exceeding 2 700 Bq/m³. There were 21 metal mines with radon concentration exceeding 1 000 Bq/m³, accounting for 28% of the total surveyed mines. The average annual effective dose of metal miners was 8.38 mSv, and that of non-metal miners was 1.01 mSv. It can be seen that the problem of high radon concentration in metal mines is very prominent. It is suggested that the protection of ventilation engineering should be strengthened in metal mines, and the monitoring of radon in the workplace and individual dose of radon in miners should be implemented. Non-uranium mines should be managed by classification of radon.

Key words: non-uranium mines, radon concentration, solid state nuclear track detector, dose estimation