Pédehontaa-Hiaa G, Holstein H, Mattsson S, Rääf C L, Stenström K E
Medical Radiation Physics Malmö, Department of Translational Medicine, Lund University, Sweden.
Medical Radiation Physics Malmö, Department of Translational Medicine, Lund University, Sweden.
J Environ Radioact. 2020 Mar;213:106141. doi: 10.1016/j.jenvrad.2019.106141. Epub 2020 Jan 3.
A powerful neutron source, the European Spallation Source (ESS), is currently under construction in Lund, Sweden (~90 000 inhabitants). Levels of tritium (H) in urine were estimated in members of the public in Lund and employees at the ESS using liquid scintillation counting, to obtain baseline levels before the start of operation of the ESS. These were compared with levels in other occupationally exposed radiation workers. Both the spallation reaction in the ESS tungsten target and the activation of various materials by the protons produced by the 5 MW linear accelerator will generate tritium, which will be released into the atmosphere mainly as tritiated water (HTO). Urinary HTO activity concentrations were determined in a total of 55 individuals belonging to four different categories: ESS employees, neighbours of the ESS, members of the general public in Lund and exposed workers from other facilities. The participants were asked to provide information on their beverage intake the day before urine sampling. The urine samples were filtered on activated charcoal and distilled before analysis. The effect of sample preparation on the isotope fractionation of urine samples was investigated by isotope ratio mass spectrometry (IRMS) of H/H, which showed no influence. IRMS was also used to investigate if the ratio between the stable hydrogen isotopes (H/H) could provide useful data of the origin, and hence the tritium concentration, of various types of drinking water. Urinary HTO activity concentrations determined using liquid scintillation counting (LSC) were found to be below the minimum detectable activity (MDA) of 2.1 Bq⋅L for most of the participants. Five of the workers actively handling organic tritiated material were found to have activity concentrations between 3.5 and 11 Bq⋅L, which were higher than the average value in local tap water of 1.5 ± 0.6 Bq⋅L. The results will be used to evaluate the radiological impact on the population from future releases of tritium resulting from the operation of the ESS.
欧洲散裂中子源（ESS）是一个强大的中子源，目前正在瑞典隆德（约9万居民）建设中。采用液体闪烁计数法对隆德公众成员和ESS员工的尿液中氚（H）水平进行了估算，以获取ESS运行开始前的基线水平。将这些水平与其他职业性暴露于辐射的工人的水平进行了比较。ESS钨靶中的散裂反应以及5兆瓦直线加速器产生的质子对各种材料的活化都会产生氚，氚将主要以氚化水（HTO）的形式释放到大气中。对总共55名属于四类不同人群的个体测定了尿中HTO活度浓度：ESS员工、ESS的邻居、隆德的普通公众以及来自其他设施的受照射工人。要求参与者提供尿液采样前一天的饮料摄入量信息。尿液样本在分析前先通过活性炭过滤并蒸馏。通过H/H的同位素比率质谱法（IRMS）研究了样本制备对尿液样本同位素分馏的影响，结果表明没有影响。IRMS还用于研究稳定氢同位素（H/H）之间的比率是否能提供有关各类饮用水来源以及氚浓度的有用数据。发现使用液体闪烁计数法（LSC）测定的尿中HTO活度浓度对于大多数参与者低于2.1 Bq·L的最低可探测活度（MDA）。发现5名积极处理有机氚化材料的工人的活度浓度在3.5至11 Bq·L之间，高于当地自来水1.5±0.6 Bq·L的平均值。这些结果将用于评估ESS运行未来释放氚对人群的辐射影响。
