ABSTRACT

The accumulation of radiocaesium in the grains of 15 rice cultivars was monitored in 2014 and 2015. The study area was a local paddy field with low soil potassium concentrations, where highly radiocaesium contaminated rice had been commercially harvested because of the Fukushima Daiichi Nuclear Power Plant accident. The concentrations of radiocaesium in the resulting brown rice were all high, ranging from 150 to 960 Bq kg⁻¹ (decay-corrected to December 2011), and the transfer factors were approximately 10- to 25-fold higher than those of previous studies. In this study, the trend of radiocaesium accumulation in each of the improved indica, aus, and japonica cultivars became clear, whereas none of the previous studies showed a clear trend in each cultivar group. The high radiocaesium accumulation in improved indica cultivars (e.g. Takanari) should be taken into account when considering the expansion of rice cultivation for processing and forage.

摘要

2014 年和 2015 年监测了 15 个水稻品种籽粒中放射性铯的积累。研究区域是当地土壤钾浓度低的稻田，由于福岛第一核电站事故，这里的高放射性铯污染水稻被商业收割. 所得糙米中放射性铯的浓度都很高，从 150 到 960 Bq kg ^-1（衰减校正至 2011 年 12 月），并且转移因子比以前的研究高约 10 到 25 倍。在本研究中，改良籼稻、aus 和粳稻品种中放射性铯积累的趋势变得清晰，而之前的研究均未显示每个品种组中的明显趋势。在考虑扩大稻谷种植以进行加工和饲草时，应考虑改良籼稻品种（例如Takanari）中的高放射性铯积累。