So what have the affected municipalities done? Fukushima Prefecture already has a handbook for citizens on how to decontaminate. The national government has promised it will come up with a plan. (It reminds me of "Blackadder" - where Baldrick always say to Blackadder at the very last moment, "I have a cunning plan ..." which is not cunning and usually very bad or useless or both to say the least.)
That national plan may be something like the one that has been apparently released by the Japanese Society of Radiation Safety Management, and it relies on the citizens' effort to locate the high radiation "hot spots" and decontaminate using the household cleaning tools and materials, as if radioactive cesium and strontium and plutonium and cobalt should be no different from dirt and rust.
One great thing about this citizen decon idea is that it won't cost much at all to the national government, other than some support money given to neighborhood associations.
Asahi Shinbun (8/31/2011) reports:
個人の住宅周辺で特に放射線量が高い「ホットスポット」の見つけ方と、効果的な除染法について、日本放射線安全管理学会がマニュアルをまとめた。雨どいの下など、放射性物質が集まりやすい場所を紹介。放射性物質が飛散しない除染法なども説明している。
The Japanese Society of Radiation Safety Management has created a manual on how to find "hot spots" in and around one's home and how to decontaminate effectively. The manual shows the locations where radioactive materials tend to accumulate, such as under the rain gutters, and explains the methods of decontamination that do not spread radioactive materials.
ホットスポットは、雨どい▽側溝▽排水溝▽マンホール周辺▽水たまりの乾燥跡▽さびた鉄材▽切り株や木材▽草木やこけの表面▽枯れ葉や土がたまった場所――などに多く見つかる。
[According to the manual,] hot spots are often found at rain gutters, side drains, manholes, locations where there were water puddles, rusted metals, tree stumps and lumber, surface of grass, trees and moss, pile of fallen leaves and dirt.
雨どいや屋根の材質がさびたトタンや凹凸が激しい瓦の場合、セシウムが吸着しやすい。ちりや枯れ葉を掃除して集めると、線量が数十倍になることもある。
Cesium tends to adhere to the rain gutters, rusted tin roofs, and roofing tiles with uneven surface. If one sweeps dust and fallen leaves and collect them, the radiation level may jump significantly.
家庭菜園で、３月中旬～下旬以降に枯れ葉などですき込み作業をした場合は、作物への放射性物質の移行に注意が必要という。
If dead leaves were plowed into the home garden after mid March, one should be aware that radioactive materials may have moved to the plants.
屋根や雨どいを除染する場合はブラシを用い、汚れが落ちにくい場合は重曹水や酢を２～３倍に薄めた水を少しかけてこする。さびた部分は、オレンジクリーナーやクレンザーなどを使うと効果的だという。
According to the manual, one should use a brush to decontaminate the roof and rain gutters. If the dirt doesn't come off easily, one may wet the surface a little with water with baking soda or with vinegar and scrub. Cleanser is effective on rusty parts.