The behaviour of iodine-125 in simulated paddy soil

The isotope tracer technique was used to study the absorption and distribution of 125I in the simulated paddy field. The results showed that 125I could be absorbed by rice and more than half of the absorbed 125I was transported to the shoot. the specific activity of 125I in each part of the rice was in order of: root>stem>leaf>grain. The accumulation of 125I in grain was the lowest (0.18% of the whole plant). The specific activity of 125I in paddy water and topsoil decreased with time. On the 60th day, the specific activity of 125I in paddy water reduced to 0.19% of the initial. In harvested rice plants, the specific activity of 125I in root, straw, husk and brown rice was 411387 cpm/g, 53880 cpm/g, 1193 cpm/g and 61 cpm/g, respectively