当评估与生态系统放射性污染相关的环境影响和风险时,源项和沉积必须与生态系统转移联系起来,暴露生物中的生物摄取和影响。因此,一个定义明确的源术语是运输的起点,剂量,影响和风险模型。在切尔诺贝利事故之后,释放了3-4吨乏核燃料,放射性粒子是实际源项的重要组成部分。由于在许多欧洲国家都观察到了切尔诺贝利颗粒,一些科学家认为放射性粒子是“切尔诺贝利事故的一个特点。“相比之下,多年来的研究表明,释放到环境中的大部分难熔元素,如铀(铀)和钚(Pu),在一系列过去的事件,如核武器试验后,涉及核武器的非关键事故,贫铀弹药的军事用途,核反应堆事故。在从核设施排放到河流或区域海洋的排放物中也观察到放射性粒子和胶体,并与倾倒在海上的核废料有关。此外,在铀开采和尾矿场以及磷酸盐或石油和天然气工业设施等其他NORM场都发现了放射性颗粒。研究还表明,诸如元素组成之类的粒子特性取决于发射源,虽然尺寸分布等特征,结构,和氧化状态影响生态系统转移也将取决于释放方案。因此,获得先进的粒子特征技术在放射生态学中是必不可少的。沉积后,局部异质性,如颗粒将不均匀地分布在环境中。因此,库存可以被低估,如果忽略放射性粒子,对粒子污染区域的影响和风险评估可能会遭受不可接受的大不确定性。本文将重点关注有助于向环境释放放射性粒子的关键来源,以及将粒子特征与生态系统行为和潜在的生物效应联系起来。
When environmental impact and risks associated with radioactive contamination of ecosystems are assessed, the source term and deposition must be linked to ecosystem transfer, biological uptake and effects in exposed organisms. Thus, a well-defined source term is the starting point for transport, dose, impact and risk models. After the Chornobyl accident, 3-4 tons of spent nuclear fuel were released and radioactive particles were important ingrediencies of the actual source term. As Chornobyl particles were observed in many European countries, some scientists suggested that radioactive particles were \"a peculiarity of the Chornobyl accident.\" In contrast, research over the years has shown that a major fraction of refractory elements such as uranium (U) and plutonium (Pu) released to the environment has been released as particles following a series of past events such as nuclear weapons tests, non-criticality accidents involving nuclear weapons, military use of depleted uranium ammunition, and nuclear reactor accidents. Radioactive particles and colloids have also been observed in discharges from nuclear installations to rivers or to regional seas and are associated with nuclear waste dumped at sea. Furthermore, radioactive particles have been identified at uranium mining and tailing sites as well as at other NORM sites such as phosphate or oil and gas industrial facilities. Research has also demonstrated that particle characteristics such as elemental composition depend on the emitting source, while characteristics such as size distribution, structure, and oxidation state influencing ecosystem transfer will also depend on the release scenarios. Thus, access to advanced particle characteristic techniques is essential within radioecology. After deposition, localized heterogeneities such as particles will be unevenly distributed in the environment. Thus, inventories can be underestimated, and impact and risk assessments of particle contaminated areas may suffer from unacceptable large uncertainties if radioactive particles are ignored. The present paper will focus on key sources contributing to the release of radioactive particles to the environments, as well as linking particle characteristics to ecosystem behavior and potential biological effects.