Instituto de Física, Universidade Federal Fluminense, Av. Gal Milton Tavares de Souza, s/no, Gragoatá, 24210-340, Niterói, RJ, Brazil.
J Environ Radioact. 2010 Feb;101(2):153-8. doi: 10.1016/j.jenvrad.2009.09.010. Epub 2009 Nov 28.
Radon and gamma radiation level measurements were carried out inside the La Carolina mine, one of the oldest gold mining camps of southern South America, which is open for touristic visits nowadays. CR-39 track-etch detectors and thermoluminescent dosimeters of natural CaF(2) and LiF TLD-100 were exposed at 14 points along the mine tunnels in order to estimate the mean (222)Rn concentration and the ambient dose equivalent during the summer season (November 2008 to February 2009). The values for the (222)Rn concentration at each monitoring site ranged from 1.8+/-0.1 kBqm(-3) to 6.0+/-0.5 kBqm(-3), with a mean value of 4.8 kBqm(-3), indicating that these measurements exceed in about three times the upper action level recommended by ICRP for workplaces. The correlations between radon and gamma radiation levels inside the mine were also investigated. Effective doses due to (222)Rn and gamma rays inside the mine were determined, resulting in negligible values to tourists. Considering the effective dose to the mine tourist guides, values exceeding 20mSv of internal contribution to the effective doses can be reached, depending on the number of working hours inside the mine.
在拉卡罗莱纳矿（La Carolina mine）内进行了氡和伽马辐射水平测量，该矿是当今南美南部最古老的金矿开采地之一，可供旅游参观。在矿洞内的 14 个点上放置了 CR-39 径迹蚀刻探测器和天然 CaF(2)的热释光剂量计以及 LiF TLD-100，以在夏季（2008 年 11 月至 2009 年 2 月）期间估算平均（222）Rn 浓度和环境剂量当量。在每个监测点的（222）Rn 浓度值从 1.8+/-0.1 kBqm(-3) 到 6.0+/-0.5 kBqm(-3)不等，平均值为 4.8 kBqm(-3)，表明这些测量值超过了 ICRP 为工作场所推荐的上限行动水平的三倍左右。还研究了矿内氡和伽马辐射水平之间的相关性。确定了矿内（222）Rn 和伽马射线的有效剂量，对游客来说可忽略不计。考虑到矿工导游的有效剂量，根据在矿内工作的小时数，内部对有效剂量的贡献可能会超过 20mSv。
