Risk Assessment of Natural Radionuclide Contamination in Lead–Zinc Sulfide Ores Mining

Lead and zinc ores are the most important natural raw materials widely used in the industry. These types of ores contain different amounts of radionuclides that expose workers to radiation during extraction, transport, and processing. In this study, 22 samples were collected, including 18 samples of lead–zinc ore and 4 samples of mining waste. Specific activities of 226Ra, 232Th, and 40K were determined using a high-purity germanium gamma radiation detector (HPGe). The specific activities of corresponding radionuclides in lead–zinc ore samples varied in the range (< 0.21–107.61), (1.91–48.13), and (< 10.16–664.04) in Bq/kg, respectively. According to the European Commission’s dose assessment instruction for workers, the effective dose absorption was calculated for different scenarios, as transport, outdoor storage, and internal storage, which varied from 0.76 to 10.23 µSv/y, 1.05–17.00 µSv/y, and 1.20–19.20 µSv/y, respectively. For all lead–zinc ore samples, effective doses in various scenarios were lower than the intervention level (1.0 × 103 μSv/y) determined by the International Commission on Radiological Protection.