Soil and vegetation sampling during the early stage of Fukushima Daiichi Nuclear Power Plant accident and the implication for the emergency preparedness for agricultural systems

Mode of Atmospheric Deposition in Forests Demonstrates Notable Differences in Initial Radiocesium Behavior

“…59−61 However, only a few dry deposition data points were available for 2011, so caution should be used in interpretation of dry deposition results. Deposition mode (wet or dry) is an important consideration for 137 Cs accumulation in the environment, as supported by other studies of Fukushima 5,7,28 and the CNPP accident. 19,22,29 Dry deposition is dependent on the particle size.…”

“…Our analyses used emergency sampling data initiated some six months postaccident (between 16 September and 9 November 2011); immediate sampling was not possible because the highly contaminated forests were too hazardous to workers. An estimated 50–60% of radionuclides deposited in cedar and pine forests remained in tree crowns during the 2011 sampling period , and had not been lost through transfer processes before initial sample collection. The contamination measured in autumn was thought to reflect general contamination patterns immediately postdeposition.…”

“…However, to obtain a reasonable number of data for dry-dominated areas, a wider range of <50% wet deposition was classified as dry-dominated. Additionally, dry site classification (areas that received less than 50% wet deposition) was based on only a few studies. ,, Future studies will need to assess classifications as data become more available.…”

“…Additionally, dry site classification (areas that received less than 50% wet deposition) was based on only a few studies. 5,7,28 Future studies will need to assess classifications as data become more available.…”

“…The majority of the FDNPP total atmospheric deposition over land surfaces was via wet deposition. ,,, However, the contamination in high forested southwestern regions was via dry deposition. , Higher radiocesium concentrations in vegetation, soils, and aboveground tree biomass are hypothesized to be a result of dry deposition of radiocesium. , Dry deposition of radiocesium contamination on grass, foodstuff, and other environmental materials was higher than wet deposition areas surrounding the Chornobyl Nuclear Power Plant (CNPP). ,,, The deposition mode is important for predicting early phase radionuclide movement in the terrestrial environment, contamination levels, and uptake by trees. Models should consider wet and dry deposition pathways to better estimate radiocesium concentrations in trees.…”