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Japan's first commercial nuclear fuel reprocessing plant is expected to release radioiodine into the atmosphere, and orchard grass plants grown in the vicinity of this plant may absorb this radioiodine. In this study, we investigated the mechanism underlying the absorption and volatilization of iodine in the leaves of orchard grass. Our findings suggest that iodine can be transferred from the leaves of this grass to the atmosphere via two routes: direct volatilization and absorption followed by volatilization. Previous studies on rice and oats also show that iodine can be absorbed by the roots and volatilized from the plant's body. Although orchard grass absorbs iodine via the leaves, the chemical form of volatilized iodine may differ from that absorbed via the roots. We applied a NaI solution to the leaves of orchard grass and analyzed the volatilized iodine. The experimental results showed that the iodine was volatilized as methyl iodide., (© The Author(s) 2024. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

We investigated the transfer of stable Cs + and I- applied as droplets directly on the fruit surface of 3-y-old plumleaf crab apple trees to the fruit interior at different developmental stages. The proportions of Cs and I transferred to the fruit flesh by harvest time were 21-66% and 41-53%, respectively, with decreasing trends as the developmental stage progressed. Most of the Cs+ was gradually transferred from the surface to the skin and flesh, while I- rapidly penetrated the fruit in the days after the application, followed by slow transfer of small proportions. For both elements, prompt penetration of the flesh occurred 1-2 d after application. A compartment model for simulating each element's behavior was constructed using all the data obtained. The Cs transfer model to the flesh can simulate the measured values well. For the model of I, prompt distribution to the skin is also necessary., (© The Author(s) 2022. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Apple is an important agricultural product in Aomori Prefecture, Japan, where the first commercial nuclear fuel reprocessing plant is currently under construction. As the behavior of radioiodine deposited on the surface of apple leaves is not well known, we studied the absorption and transfer to fruit of stable iodine applied onto the leaf surface. Droplets of NaI solution were applied to the leaf surface $\sim$86-89 days after flowering. The leaves were collected periodically and washed with detergent solution, followed by determination of iodine amounts absorbed or remaining on the leaf surface. Subsequently, iodine levels were determined separately for each part of the apple tree. Our results indicated that iodine applied on the surface of the leaf was absorbed and accumulated inside the leaf, but the transfer of absorbed iodine to the fruit was negligible; hence, iodine was less likely to accumulate in the fruit., (© The Author(s) 2022. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

We measured the concentrations and determined the distribution of the stable isotope 127I in the marine organisms. Marine fish were collected from the Pacific Ocean near Aomori, Japan. The mean 127I concentrations in the muscle of marine fish ranged from 0.67 μg g-1-wet weight (ww) in cherry salmon to 0.84 μg g-1-ww in fat greenling. Among the tissues measured, the muscle showed the lowest levels of 127I in all fish species. The highest 127I concentration in the tissues of marine fish was observed in the ovary of fat greenling. The mean 127I concentration in the of Japanese scallop ranged from 0.06 μg g-1-ww in adductor muscle to 5.49 μg g-1-ww in mid-gut gland. The 127I concentrations in seaweeds were 67 μg g-1-dry weight (dw) in sea lettuce and 1783 μg g-1-dw in kombu. Thus, the distribution of 127I concentration in marine organisms varied considerably depending on the tissue., (© The Author(s) 2022. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

A non-destructive analysis method for total bromine (Br) and iodine (I) contents in soil was established using polarizing energy-dispersive X-ray fluorescence (EDXRF) spectrometry. The matrix-corrected intensity of Br and I Kα X-rays from pressed pellets of soil powder samples was calibrated with their contents measured by inductively coupled plasma (ICP)-mass spectrometry after pyrohydrolysis preparation. The calibration curves for Br and I were successfully obtained in the concentration ranges 3.8–223 mg kg−1 and 0.91–54 mg kg−1 respectively. Repeated analyses of the same sample with polarizing EDXRF spectrometry within one day and after approximately 1.5 years showed good reproducibility of the measurement results. The lower limits of detection for Br and I were 0.14 mg kg−1and 0.34 mg kg−1 respectively. The established analytical method for total Br and I contents in soil is non-destructive, simple and rapid, and is suitable for routine analysis. Trace elements such as rubidium (Rb), strontium (Sr), yttrium (Y), zirconium (Zr), niobium (Nb), cadmium (Cd), tin (Sn), antimony (Sb), caesium (Cs), barium (Ba), light rare earth elements and lead (Pb) were also measurable simultaneously under the identical operational conditions as those for Br and I measurements. [ABSTRACT FROM PUBLISHER]

We investigated the vertical distribution of the soil–soil-solution distribution coefficients ( K d ) of 125 I, 137 Cs, and 85 Sr in organic-rich surface soil and organic-poor subsurface soil of a pasture and an urban forest near a spent-nuclear-fuel reprocessing plant in Rokkasho, Japan. K d of 137 Cs was highly correlated with water-extractable K + . K d of 85 Sr was highly correlated with water-extractable Ca 2+ and SOC. K d of 125 I − was low in organic-rich surface soil, high slightly below the surface, and lowest in the deepest soil. This kinked distribution pattern differed from the gradual decrease of the other radionuclides. The thickness of the high- 125 I − K d middle layer ( i.e. , with high radioiodide retention ability) differed between sites. K d of 125 I − was significantly correlated with K d of soil organic carbon. Our results also showed that the layer thickness is controlled by the ratio of K d -OC between surface and subsurface soils. This finding suggests that the addition of SOC might prevent further radioiodide migration down the soil profile. As far as we know, this is the first report to show a strong correlation of a soil characteristic with K d of 125 I − . Further study is needed to clarify how radioiodide is retained and migrates in soil. [ABSTRACT FROM AUTHOR]