Elless M P, Armstrong A Q, Lee S Y
Phytotech, Inc., Monmouth Junction, NJ 08852, USA.
Health Phys. 1997 May;72(5):716-26. doi: 10.1097/00004032-199705000-00007.
Remediation of uranium-contaminated soils is considered a high priority by the U.S. Department of Energy because these soils, if left untreated, represent a hazard to the environment and human health. Because the risk to human health is a function of the solubility of uranium in the soils, the objectives of this work are to measure the uranium solubility of two contaminated soils, before and after remedial treatment, and determine the health risk associated with these soils. Two carbonate-rich, uranium-contaminated soils from the U.S. Department of Energy Fernald Environmental Management Project facility near Cincinnati, Ohio, as well as two nearby background soils were characterized and their uranium solubility measured in a 75-d solubility experiment using acid rain, groundwater, lung serum, and stomach acid simulants. Results show that the soluble uranium levels of each soil by each simulant are greatly influenced by their contamination source term. Risk calculations and biokinetic modeling based on the solubility data show that the risks from the soil ingestion and groundwater ingestion pathways are the predominant contributors to the total carcinogenic risk, whereas the risk from the soil inhalation pathway is the smallest contributor to this risk. However, kidney toxicity was the greater health concern of the Fernald Environmental Management Project soils, primarily from undiluted ingestion of the groundwater solution following contact with the contaminated soils. Sensitivity analyses indicate that uranium solubility is a key parameter in defining kidney toxicity; therefore, without proper consideration of the solubility of radionuclides/metals in untreated and treated soils, important factors may be overlooked which may result in soil cleanup goals or limits which are not protective of human health and the environment. We recommend that characterization and measurement of target radionuclides/metals solubilities should also be required by the regulatory community to support the establishment of scientifically-sound, site-specific, soil cleanup goals or limits.
美国能源部认为对受铀污染土壤进行修复是一项高度优先的任务，因为这些土壤若不进行处理，会对环境和人类健康构成危害。由于对人类健康的风险是铀在土壤中溶解度的函数，因此本研究的目标是测量两种受污染土壤在修复处理前后的铀溶解度，并确定与这些土壤相关的健康风险。对来自俄亥俄州辛辛那提附近的美国能源部弗纳尔德环境管理项目设施的两种富含碳酸盐的铀污染土壤以及附近的两种背景土壤进行了表征，并在一项为期75天的溶解度实验中，使用酸雨、地下水、肺血清和胃酸模拟物测量了它们的铀溶解度。结果表明，每种模拟物测得的每种土壤的可溶性铀水平受其污染源项的影响很大。基于溶解度数据的风险计算和生物动力学模型表明，土壤摄入和地下水摄入途径带来的风险是总致癌风险的主要贡献因素，而土壤吸入途径带来的风险对该总风险的贡献最小。然而，肾脏毒性是弗纳尔德环境管理项目土壤更值得关注的健康问题，主要源于接触受污染土壤后直接摄入地下水溶液。敏感性分析表明，铀溶解度是定义肾脏毒性的关键参数；因此，如果没有适当考虑未处理和已处理土壤中放射性核素/金属的溶解度，可能会忽略重要因素，这可能导致土壤清理目标或限值无法保护人类健康和环境。我们建议监管机构也应要求对目标放射性核素/金属的溶解度进行表征和测量，以支持制定科学合理、针对具体场地的土壤清理目标或限值。
