安徽省歙县石煤矿区天然放射性环境调查

对安徽省歙县石煤矿区开展了γ辐射空气吸收剂量率、空气氡活度浓度的测量,并系统采集了土壤、岩石、石煤、煤渣、煤矸石、水系沉积物等固体环境介质及地表水、地下水样品。结果表明,区内γ剂量率平均值为121.5 nGy/h,远高于安徽省和全国背景值,γ辐射水平受地层/岩性的控制,高值点集中在石煤矿山。室内、外氡活度浓度均值分别为116.8 Bq/m³、47.1 Bq/m³,显著高于背景水平。石煤、煤渣、煤矸石、碳化砖中²³⁸U和²²⁶Ra的含量较高,且碳化砖内、外照射指数超过建筑材料放射性核素限值标准,严禁作为主体建筑材料使用。石煤的私自开发造成周边河段放射性核素浓度明显增加,矿坑水中总α超过污水排放限值,应加强监管。

Investigation of natural radioactive environment in a bone coal mine area,in She County,Anhui Province

The γ-radiation air absorbed dose rate and radon concentration were measured in the She County coal mine area of Anhui Province, and the environmental media (soil, rock, stone coal, coal slag, coal gangue, sediment, surface water and groundwater) were systematically collected and analyzed. The results showed that the average gamma dose rate in the mine region is 121.5 nGy/h, which is much higher than the background value of Anhui Province and entire China. The gamma radiation level is controlled by the stratum/lithology, and the high value points are concentrated in bone coal mine. The mean concentrations of indoor and outdoor radon were 116.8 Bq/m³ and 47.1 Bq/m³ respectively, which were significantly higher than the background level. The concentration of ²³⁸U and ²²⁶Ra in bone coal, coal slag, coal gangue and carbonized brick is high, and the internal and external exposure index of carbonized bricks exceeds the radionuclide limit of building materials, so it is strictly prohibited to use them as main building materials. The development of bone coal has caused a significant increase in the concentration of radionuclides in the surrounding river sections, and the total α in the mine water exceeds the sewage discharge limit. Therefore supervision should be strengthened.