Fukushima radioactive mushrooms report details concerns to Olympic tourists and athletes?

It might be noted also that the upcoming 2020 Olympics will put a strain on the planned cleanup of domestic and public areas and mean that it will be likely to put back any possible clean up plans for the forested areas. Also, as soil sampling has not generally been effective, will there be a threat to Olympic tourists and athletes who might venture into these largely unmapped and untested areas?

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Published on 27 July 2017

by Shaun McGee

A study (Source here) Published online on the 27th July 2017 has been done concerning the radiation contamination found in Kawauchi village some 30 km from the Fukushima Daichi nuclear disaster plant.

The study gives measurements of radiocesium found in only 3 mushroom types and describes that no cesium was found in 3 others. Other mushroom types were not assessed. The studies on contamination in mushrooms in the Fukushima Prefecture only began in 2013, some 2 years after the nuclear disaster. The quantity of samples is surprisingly limited to just a few hundred samples.

There are approximately 22 edible wild mushroom species, 3 medicinal species and 3 species that are disputed to be edible. Another 8 are deemed poisonous, inedible or have mind altering effects (Source here). It might be noted that some insect species do consume or live in poisonous mushrooms.

The three mushrooms sampled were;

Sarcodon aspratus

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Radiocesium concentrations was detected in 68 of 68 samples (100%)

The maximum activity concentration was 5,600 Bq/kg of ¹³⁷Cs

Hygrophorus russula

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Radiocesium concentrations was detected in 17 of 17 samples (100%)

The maximum activity concentration was 2,200 Bq/kg of ¹³⁴Cs

Albatrellus confluens

Albatrellus-confluens

Radiocesium concentrations was detected in 9 of 10 samples (90%)

Comparing a 2014 study to 2015 measurements there was a reduction in Cesium 134 (which has a shorter half life) but cesium 137 remained the same.

The new report did make this comment on Forest contamination;

“Although the residential houses have been extensively decontaminated since the accident, the forests of Fukushima Prefecture have not been decontaminated yet¹⁵. As our results suggest that it takes time to observe a decrease in the radiocesium in wild mushrooms, careful discussion will be needed among stakeholders to determine the necessity of decontaminating the forests in Fukushima.”

It might be noted also that the upcoming 2020 Olympics will put a strain on the planned cleanup of domestic and public areas and mean that it will be likely to put back any possible clean up plans for the forested areas. Also, as soil sampling has not generally been effective, will there be a threat to Olympic tourists and athletes who might venture into these largely unmapped and untested areas? (Source on problems with Olympic funding impacts to local decontamination from a recent report here)

General contamination in foodstuffs

652 of 1986 (32.8%) sampled edible wild plants and fungi were found to be above the 100 Bq/kg limit whereas local food and fruit produced had low figures in going over this threshold limit (under 2 percent).

The report makes another further point concerning the lack of testing of soil in the area;

“Our study has several limitations. We could not evaluate the relationship between radiocesium activity concentrations in mushroom samples and the concentrations in soil due to insufficient soil samples. Further comprehensive studies are necessary to evaluate the activity concentrations of radiocesium in mushroom samples in Fukushima after the accident. Additional analytical uncertainties arise because the committed effective doses from dietary intake of mushrooms cannot measure day-to-day variations in individuals. Further, we did not evaluate the potential loss of radiocesium upon cooking in mushrooms. The influence of eating habits, including cooking methods, must be considered. In this study, we evaluated internal doses from the ingestion of mushrooms, but we did not evaluate the external doses received from being in contaminated forest areas while collecting mushrooms. Further comprehensive analyses with detailed reports on all areas around FDNPP are needed.”