Lanka Mineral Sands Ltd (LMS) is a company operating in Pulmoddai, Sri Lanka, mining for rare earth minerals along with monazite which contains thorium that emits ionizing gamma and alpha radiation on decay. The objective of the study was to determine the background radiation levels and selected radionuclides and then to correlate these levels with the frequency of micronuclei (MN) among persons residing in the vicinity of LMS. A cross-sectional study was conducted among persons of both sexes between 35 and 45 years of age residing in the vicinity of LMS. Background radiation measurements were obtained by a survey metre, and gamma spectrometry was done on soil samples. Five millilitres of venous blood was drawn for cytokinesis-blocked MN assay. Background radiation levels measured by the survey metre; 232Th, 226Ra and 210Pb mass activities in soil were highest in the samples collected from the LMS. The background radiation measurements positively correlated with MN frequency although the magnitude of the correlation was small (r = 0.176, p = 0.04). This implies that chronic long-term exposure to low-dose radiation may result in genotoxicity. Prospective large-scale studies are recommended to evaluate the long-term effect of exposure to low-dose radiation at Pulmoddai.

中文翻译：

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斯里兰卡某矿砂采矿厂附近的背景辐射水平：辐射测量值与微核频率的相关性。

兰卡矿产金沙有限公司 (LMS) 是一家在斯里兰卡普勒莫代经营的公司，开采稀土矿物以及含有钍的独居石，在衰变时会发出电离的伽马和阿尔法辐射。该研究的目的是确定背景辐射水平和选定的放射性核素，然后将这些水平与居住在 LMS 附近的人的微核 (MN) 频率相关联。对居住在 LMS 附近的 35 至 45 岁的男女进行了一项横断面研究。通过测量仪获得背景辐射测量值，并对土壤样品进行伽马光谱测量。抽取 5 毫升静脉血用于胞质分裂阻断 MN 测定。测量仪测量的背景辐射水平；第 232 天，从 LMS 采集的样品中土壤中 226Ra 和 210Pb 的质量活度最高。背景辐射测量值与 MN 频率呈正相关，尽管相关性的幅度很小（r = 0.176，p = 0.04）。这意味着长期长期暴露于低剂量辐射可能会导致遗传毒性。建议进行前瞻性大规模研究，以评估 Pulmoddai 暴露于低剂量辐射的长期影响。