Finding it "uneconomical" to clean up residual isotopes from the triple meltdown at the Fukushima Daiichi nuclear power complex, Fukushima Central Television is reporting that the Ministry of the Environment is in negotiations with local municipalities to raise the residual ambient radiation limits from .23 microsieverts/hour to something in the .4-.6 range. However, this is not yet official policy - the Ministry for the Environment will be having a meeting with affected municipal governments on June 15, and the official announcement on the new policy is not expected for two to three months. It appears that raising the residual radiation standards is considered essential to "recovery" from the nuclear disaster.
Local governments have been complaining that current target levels for residual ambient radiation are "unrealistic", and that attempting to meet them is both too expensive and is taking too long. The general populace, however, is outraged that the government would consider raising the limits. There is a deep mistrust of the government on the issue of nuclear power following the Fukushima Daiichi disaster, and this is exacerbated in this case by the fact that the head of the Ministry of the Environment wanted to ban the use of personal radiation meters by citizens. The Japanese people are not convinced that the government has their best interest at heart.
Supposedly, the new hourly limits would still keep the annual dose under one millisievert. The existing standard was based on the presumption that a typical resident would spend eight hours outdoors, and sixteen hours in a one or two story wooden building. However, actual dosimeter readings have shown the average exposure to be less than was calculated. Apparently the typical citizen lives, works, or goes to school in a taller building, a building made of cement, and/or spends less time outdoors. There is concern, however, that although the average citizen may be less exposed than presumed, for those individuals who DO live in wooden buildings, or spend more time outdoors, the proposed new standards could be detrimental.
For those considering the potential health implications of these changes, it is important to note that the exposure levels are additional exposure from the disaster - in other words, the levels are calculated after subtracting the average "background" radiation of .04 μSv/h in Fukushima before the meltdowns from the current ambient radiation level.