Department of Chemical & Materials Engineering, New Mexico State University, Las Cruces, NM 88003, USA.
Department of Chemical Engineering, Institute for Materials Research and Innovations, University of Louisiana at Lafayette, Lafayette, LA 70504, USA.
Ecotoxicol Environ Saf. 2022 Sep 1;242:113849. doi: 10.1016/j.ecoenv.2022.113849. Epub 2022 Jul 6.
Groundwater may contain radioactive substances which can be dangerous to human health. Concentrations of natural radionuclides polonium (Po), thorium (Th), uranium (U), and radium (Ra) isotopes were measured in groundwater samples collected from different locations in the vicinity of the Waste Isolation Pilot Plant (WIPP) site in Carlsbad, New Mexico. The average values of gross activity concentrations of Po, Th, U, U, Ra and Ra isotopes were determined to be 1.62 Bq L in shallow groundwater and 5.88 Bq L in deep groundwater, respectively. The total radioactivity in deep groundwater was higher than that in shallow groundwater, and most of the radioactivity in the water is from Ra. Furthermore, the effective doses for ingestion of natural radionuclides were about 0.333 mSv y for shallow groundwater and about 1.338 mSv y for deep groundwater samples, which are higher than the World Health Organization (WHO, 2017) guideline level (0.1 mSv y) for drinking water. Ra dominated the total ingestion dose, contributing 93.06 % and 75.40 % of the total effective doses to the deep and shallow groundwater, respectively. The ingrowth and decay of natural radionuclides suggested that Ra/Ra ratio can be a useful indicator of the source of radioactive contamination. The radioactivity data obtained from the investigated groundwater samples can be used to establish a baseline for radioactivity levels in groundwater around the WIPP site.
地下水可能含有放射性物质，这些物质对人类健康可能有害。在新墨西哥州卡尔斯巴德的废物隔离示范厂（WIPP）附近的不同地点采集的地下水样本中，测量了钋（Po）、钍（Th）、铀（U）和镭（Ra）同位素的天然放射性核素浓度。浅层地下水中 Po、Th、U、U、Ra 和 Ra 同位素的总活度浓度的平均值分别为 1.62 Bq/L 和 5.88 Bq/L，深层地下水中的总活度浓度分别为浅层地下水的两倍。深层地下水的总放射性比浅层地下水高，水中的大部分放射性物质来自 Ra。此外，浅层地下水中天然放射性核素的摄入有效剂量约为 0.333 mSv/y，深层地下水中的摄入有效剂量约为 1.338 mSv/y，均高于世界卫生组织（WHO，2017 年）对饮用水的指导水平（0.1 mSv/y）。Ra 主导总摄入剂量，对深层和浅层地下水的总有效剂量的贡献分别为 93.06%和 75.40%。天然放射性核素的生长和衰变表明，Ra/Ra 比可以作为放射性污染来源的有用指标。从调查的地下水样本中获得的放射性数据可用于为 WIPP 场址周围地下水中的放射性水平建立基准。
