School Children Used To Clean Radioactive Swimming Pools: Dirt Contained Cesium At 17,020 Becquerels Per Kg

17,020 Becquerels/Kg Cesium in Dirt Cleaned Out from Elementary School Swimming Pool in Ibaraki Prefecture (EX_SKF, July 5, 2011):

And who did the cleaning? Children.

Now on to one of the favorite topics of this blog: Swimming pools in Japan.

Well they did it again, this time the Board of Education in Joso City in Ibaraki Prefecture. Back in May, as one of the annual, educational events of the schools, public elementary schools and junior high schools in Joso City had their pupils clean out the school swimming pools in preparation for the school swimming classes during summer. The teachers also helped out. Together, they cleaned the pools and scooped out the dirt that had accumulated at the bottom of the pools.

5 schools kept the dirt in a corner of the schoolyards. At one elementary school, a concerned PTA member decided to measure the radiation of the dirt. The result? 17,020 becquerels/kg of radioactive cesium.

There are 14 public elementary schools, 5 junior high schools in Joso City. The city’s Board of Education runs both elementary schools and junior high schools.

From Mainichi Shinbun (7/5/2011):

常 総市の市立小学校が5月にプール清掃を教員と児童で行った際にかき集めた泥土から、1キロ当たり1万7020ベクレルの放射性セシウムが検出されたこと が分かった。環境省が放射性物質汚染がれきについて定めた埋め立て許容基準の2倍に当たり、この学校は泥土を隔離。これを受けて市教育委員会が4日、全小 中学校のプール泥土の残存状況を調査したところ、同校の他に4小学校が敷地内に泥土を置いていることが明らかになった。

It was disclosed that 17,020 becquerels per kilogram of radioactive cesium was detected from the dirt that were scooped out from the swimming pool when the teachers and pupils of one public elementary schools in Joso City did the cleaning of the pool in May. The amount is more than twice the safety limit set by the Ministry of the Environment for the radioactive debris that could be buried. The school moved the dirt in a separate area. Upon this news, the city’s Board of Education surveyed the situation of the pool dirt in city’s elementary schools and junior high schools on July 4, and found out there were 4 other elementary schools who had kept the dirt on the school premises.


A member of the school’s PTA collected a bucketful of this dirt on June 11, and sent 3 kilograms of it to a laboratory specializing in radiation measurement. The result, which was delivered on June 29, showed the sample contained 7,700 becquerels/kg of cesium-134 and 9,320 becquerels/kg of cesium-137.


The safety limit for disposal of radioactive debris, as announced by the Ministry of the Environment last month, is 8,000 becquerels/kg. If it is below that limit, you can bury the debris. If it exceeds, then the measures will be necessary to shield the radiation. The Ministry of Education and Science says the dirt from the pool would be treated in the same manner.


The vice principal of the elementary school said, “As an activity to promote love for the school, 5th and 6th graders participated in the cleaning.” The school didn’t think of the radiation contamination then. The city’s Board of Education instructed the principals of the city’s schools on May 25 to pay attention to the health of pupils when cleaning the swimming pools, but by that time 4 schools including this elementary school had already had pupils clean the pools.

市教委は同校 のプール泥土を産業廃棄物として業者に処理を委託することを決定。他の4校の泥土については5日に放射線量を測り、校庭よりも高い数値が出た場合は産廃と して処理する方針。坂巻幸一教育部長は「プール清掃は学校の指導の一環だが、配慮が足りなかったかもしれない」と述べた。

The city’s Board of Education has decided to have a company that specializes in disposal of industrial waste to dispose the pool dirt from the school. As to the dirt at 4 other schools, the radiation will be measured on July 5. If the numbers are higher than those for the schoolyards, the dirt will be disposed as industrial waste. Koichi Sakamaki, manager for education [at the Board of Education] said, “Cleaning the swimming pools is part of the school instruction. But we should have been a bit more careful.”

調査したPTA関係者は「子どもが放射性物質に汚染され た泥土の処理を行った事実を、将来の健康も考えて記録に残してほしい。市教委はきちんと対策を取り、情報を公開すべきだ」と指摘する。一方、県教委保健体 育課は「評価基準はないが、掃除の後きちんと手を洗えばそれほど神経質になることはない」としている。

The member of the school’s PTA says, “That the children did the cleanup of radioactive dirt should be recorded as such , for the future health monitoring. The city’s Board of Education should provide appropriate countermeasures, and disclose information fully.” The Board of Education of Ibaraki Prefecture, on the other hand, says “While it’s true there is no standard for evaluating the pool dirt, but there is no need to be nervous as long as you wash your hands after cleaning the pool.”

How could the school not think of radiation contamination, when the radioactive plume from Fukushima I Nuke Plant was constantly blowing over Ibaraki Prefecture and the air radiation level remains elevated? (I guess the vice principal didn’t have access to the Internet to take a look at those foreign meteorological agencies’ simulations…)

No matter. Cleaning is over now anyway, and the rest of the schools didn’t even keep the dirt. But the pool water is clean, I’m sure.

But since when the dirt that contains that much radioactive cesium can be disposed as “industrial waste”, instead of nuclear waste?

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