Title
Effect of the 2011 Fukushima Daiichi nuclear power plant accident on Cryptomeria japonica wood components
Authors
AI VAN TRAN and MAKOTO YANAGA

Received January 17, 2023
Published Volume 57 Issue 7-8 July-August
Keywords Cryptomeria japonica, bark, sapwood, heartwood, lignin, holocellulose, 134Cs, 137Cs

Abstract
Radiocontaminated Cryptomeria japonica from Iitate village in Fukushima was analyzed in terms of the bark, sapwood and heartwood. Both 134Cs and 137Cs activities were confirmed in these wood components. The sum of 134Cs and 137Cs activities was the highest in the bark, the lowest in the sapwood and that of the heartwood in between. Although the holocellulose isolated from the bark was contaminated by 134Cs and 137Cs activities, these radiocesiums were not detected in the holocelluloses from sapwood and heartwood. Similar results were obtained for dioxane lignins isolated from sapwood and heartwood. An examination of the FTIR spectra of holocelluloses and dioxane lignins from the bark, sapwood and heartwood of C. japonica originated from radiocontaminated Iitate, and radiocontamination-free Fuji areas revealed that the structures of the constitutions of the former wood were not altered by the radiocontamination. Furthermore, the FTIR spectra of the outer bark and inner bark holocelluloses from the artifically 137Cs-impregnated Fuji tree were similar to those of the outer bark and inner bark holocelluloses of the radiocontaminated Iitate tree.