Abstract
Shiitake cultivation is being done even in areas affected by radioactive contamination. When using logs in this area, only three trees are inspected before cutting the wood. The results are used to estimate the level of contamination in the log. We compare the results obtained to the index value prior to cutting the wood. Despite these tests, hodagi with high radiocesium concentration and fruit bodies with high radiocesium concentration are often found by a later check. Therefore, as a result of investigating these production lots, wood that exceeded the index value was included. It is rare for hodagi to get contaminated during indoor Shiitake cultivation. It was thought that these hodagi already had a high radiocesium concentration before use in Shiitake cultivation. In sample inspection, there is a possibility that some logs contain higher radiocesium concentration than the results obtained from analysis of test logs. Reliable inspections to eliminate these logs are needed when using trees cut from radioactively contaminated areas. Although the transition coefficient of radiocesium from hodagi to shiitake mushrooms is set at 2.0, it was considered necessary to continue investigation.
