Strange Iodine 131 Findings In Fukushima Prefecture

Where: Nihonmatsu City, Fukushima Prefecture
When: January 2017 to February 2018

This was brought to our attention that some unusual findings of iodine 131 were going on in Fukushima prefecture. Questions were being asked online if this could be caused by something at Fukushima Daiichi. This part appears unlikely for a couple of reasons. If there was a recriticality at the plant large enough to have iodine 131 show up in sewage sludge there would have been increased gamma radiation in the region. This would have been picked up on citizen owned radiation monitoring. There would have also been some increase in cesium 134 & 137 detection at the same time. This was not found. An environmental run off type cause is also unlikely as rainfall was not tied to the increases.

The prefecture website has an FAQ on the ongoing findings of iodine 131 in sewage sludge at the various sewage plants. They admit that there are facilities in the prefecture using iodine 131 for thyroid cancer treatments. Patients are held at the hospital until their radiation levels drop to a specific level.

Some of these increased levels of iodine 131 in sewage sludge in Nihonmatsu City appeared unusual. Most months showed an increase then a standard decrease if there was any reading at all. December 2017 showed peaks, decreases and then an abrupt peak. Rainfall records have no influence on the found iodine 131 readings. Could the high and erratic levels be radiation treatment related? They seem unusual compared to findings in other parts of Japan and the US.

Some possible explanations:
Possibly a large number of people were being treated in December 2017 but not all at the same time. Another possibility is that the hospital facility was improperly handling sewage waste from the radiation treatment facility. Hospitals are normally required to hold patient wastes in an isolated tank for a set number of days before releasing it to the community sewage system. This is supposed to allow for the radioactive isotope to decay. If that was not being done properly this could have contributed to the strange spikes in December. Not following proper patient protocols could have also caused some of the spikes. If people were being allowed to go home too early, use non isolated toilet facilities etc. this could have contributed to the unusual spikes.

Nihonmatsu has a number of hospitals in the city.  We could not find one that specifically announced they have a cancer treatment center conducting thyroid radiation treatments. The large number of facilities in the city may mean multiple facilities could be doing such treatments.


This article would not be possible without the extensive efforts of the SimplyInfo research team
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