A dataset of 137Cs activity concentration and inventory in forests contaminated by the Fukushima accident

Abstract

The majority of the area contaminated by the Fukushima Daiichi Nuclear Power Plant accident is covered with forests. We developed a dataset for radiocaesium (137Cs) in trees, soil, and mushrooms measured at numerous forest sites. The 137Cs activity concentration and inventory data reported in scientific journal papers written in English and Japanese, governmental reports, and governmental monitoring data on the web were collated. The ancillary information describing the forest stands were also collated, and further environmental information (e.g. climate) was derived from the other databases using longitude and latitude coordinates of the sampling locations. The database contains 8593, 4105, and 3189 entries of activity concentration data for trees, soil, and mushrooms, and 471 and 3521 entries of inventory data for trees and soil, respectively, which were collected from 2011 to 2017, and covers the entire Fukushima prefecture. The data can be used to document and understand the spatio-temporal dynamics of radiocaesium in the affected region and to aid the development and validation of models of radiocaesium dynamics in contaminated forests.

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

“…Radiocesium Analysis of Soil and Organic Material. The 134 Cs (605 and 796 keV) and 137 Cs (662 keV) in organic material and soil were measured using a high-purity germanium detector (HPGe; GC3018, Canberra Industries Inc., Japan, Tokyo). An efficiency calibration of the detector was performed with volume radioactivity standard gamma sources (MX033U8PP, Japan Radioisotope Association, Tokyo, Japan).…”

“…We also utilized radiocesium activity concentrations in various tree components (i.e., branches, leaves, and wood) from a large data set. 41 Our approach used the initial 137 Cs terrestrial concentrations following the Fukushima accident 42 to normalize measurement data, combined with spatial mapping of the ratio of wet deposition to the total 137 Cs deposition. 26 Next, the mode of 137 Cs deposition was estimated for each forest.…”

“…41 Our approach used the initial 137 Cs terrestrial concentrations following the Fukushima accident 42 to normalize measurement data, combined with spatial mapping of the ratio of wet deposition to the total 137 Cs deposition. 26 Next, the mode of 137 Cs deposition was estimated for each forest. This methodology allowed us to evaluate the influence of wet and dry deposition on forests of varying species and tree stand densities.…”

“…This methodology allowed us to evaluate the influence of wet and dry deposition on forests of varying species and tree stand densities. Thus, we assessed conditions that may cause higher levels of 137 Cs deposition on forests and increased ambient dose rates. We hypothesize that contamination produced by dry deposition in dense forests caused higher 137 Cs concentrations in forests.…”

Radiocaesium Contamination of Mushrooms at High- and Low-Level Chernobyl Exposure Sites and Its Consequences for Public Health

“…This effect has already been examined closely over decades after pollution events [2,5]. Due to the impact of nuclear weapon tests, the Chernobyl accident in 1986 [4,6,7] and the Fukushima accident in 2011 [8], soils around the globe are contaminated by radiocaesium [9].…”