Hunt G J
Ministry of Agriculture, Fisheries and Food, Fisheries Laboratory, Lowestoft, Suffolk, England.
Health Phys. 1997 Apr;72(4):558-67. doi: 10.1097/00004032-199704000-00007.
First, some of the early work is reviewed on exposure pathways in connection with proposed and early liquid radioactive waste discharges from Sellafield. The main historical features of these discharges, affected by relevant plant operations, are then briefly described. The important radiological exposure pathways resulting from the discharges and people's consumption and occupancy habits are considered. To place the changing scenario onto a consistent basis using present-day methodology, a reconstruction of exposures has been carried out using environmental monitoring data and models. The three major pathways are examined of Porphyra/laverbread consumption in South Wales, fish and shellfish consumption near Sellafield, and external exposure over local and more distant sediments. The results show that over the period 1952 to about 1970 the laverbread pathway was probably critical, taking a cautious approach. Effective dose rates fluctuated at around 1 mSv y(-1) from about 1956 to 1971. From about 1970 to 1985, the fish and shellfish pathway was likely to have been critical, with effective dose rates peaking at about 2 mSv y(-1) in 1975-1976. External exposure was likely to have been of lesser importance than the other two pathways until about 1985, when with the retention of previously-released radiocesium on sediments it has become dominant. This phenomenon applies particularly further afield where radiocesium concentrations have been slower to decline; in the Ribble estuary, houseboat dwellers have been the critical group from about 1985. Effective doses have been at about 0.3 mSv y(-1) and declining; they are due to the effects of radiocesium discharges in earlier years. Dose rates have remained within contemporary ICRP dose limits.
首先，回顾了一些早期关于与塞拉菲尔德提议的以及早期液态放射性废物排放相关的暴露途径的工作。然后简要描述了受相关工厂运营影响的这些排放的主要历史特征。考虑了排放以及人们的消费和居住习惯所导致的重要放射性暴露途径。为了使用当今的方法将不断变化的情况置于一致的基础上，利用环境监测数据和模型对暴露情况进行了重建。研究了南威尔士紫菜/调味紫菜消费、塞拉菲尔德附近鱼类和贝类消费以及当地和更远处沉积物的外部暴露这三种主要途径。结果表明，在1952年至约1970年期间，采取谨慎的方法，调味紫菜途径可能是关键的。从大约1956年到1971年，有效剂量率在约1 mSv y⁻¹ 左右波动。从大约1970年到1985年，鱼类和贝类途径可能是关键的，有效剂量率在1975 - 1976年达到约2 mSv y⁻¹ 的峰值。直到大约1985年，外部暴露可能比其他两种途径的重要性要小，那时由于先前排放的放射性铯在沉积物中的滞留，外部暴露变得占主导地位。这种现象在更远的地方尤其明显，那里放射性铯浓度下降得较慢；在里布尔河口，自大约1985年以来，船屋居住者一直是关键群体。有效剂量约为0.3 mSv y⁻¹ 且在下降；这是早年放射性铯排放的影响所致。剂量率一直保持在当代国际辐射防护委员会的剂量限值之内。
