Narrow Results

The Fukushima Daiichi Nuclear Power Plant (FDNPP) accident in 2011 caused the widespread contamination of Fukushima Prefecture by radioactive cesium. The cesium radioisotopes are considered to have remained in the soil for seven years. We investigated this situation by analyzing soil from paddy fields in the area. We investigated the structure of soil particles using scanning electron microscopy–energy dispersive X-ray spectroscopy (SEM–EDS) and autoradiogram (ARG). We estimated the percentage of clay in the soil based on its composition, and then obtained the radioactivity of the cesium radioisotopes for each soil particle size as a function of penetration. The cesium radioisotopes were exponentially distributed in soil containing a large proportion of clay. Hence, we confirmed that the quantity of clay in the soil is a very important factor with respect to the possibility of the resumption of agriculture in the restricted area.

The study of soil-to-plant transfer of radionuclides has attracted considerable attention from a large number of researchers because of the continuous pollution of soils and the effects of radionuclides on plants. In addition, it is one of the important routes for radionuclide entry into the food chain, leading to humans’ exposure to radiation. This chapter focuses on the influence of radionuclides on plant growth, with a particular emphasis on the ratio of these substances in soil and plants concerning nutrition. It is shown in this review that physical and chemical processes and biological accumulation influence the uptake and fate of radionuclides in plants. It is reported that soil contamination by radionuclides affects plant survival rates and inhibits their growth. The effects of radionuclides on plant growth depend on the type of plants, soil properties, initial radionuclide concentration in the soil, and the duration of exposure for the plants. However, some plants have developed radionuclide tolerance mechanisms and accumulate a significant amount of radionuclides, making them suitable for soil remediation.