nuclear-news

Japan wants to measure individuals’ radiation exposure, not air doses

Ministry seeks to focus on individual radiation exposure The Yomiuri Shimbun 2 Aug 14 The Environment Ministry has compiled a report calling for decontamination work in areas affected by the crisis at Tokyo Electric Power Co.’s Fukushima No. 1 nuclear power plant to be based on measurements of individuals’ radiation exposure doses, instead of air doses.

The current measurement method has led to the establishment of a de facto air dose maximum of 0.23 microsievert per hour, making it difficult for relevant municipalities to implement decontamination efforts appropriate to residents’ lifestyles and behavioral patterns.

By focusing on individual radiation doses, which are likely to demonstrate more accurately what impact radiation has on people’s health, the municipalities could conduct decontamination and other measures to combat radiation more effectively. The ministry drew up the report after studying four cities in Fukushima Prefecture: Fukushima, Koriyama, Soma and Date. Senior Vice Environment Minister Shinji Inoue presented the report to the mayors of the cities on Friday.

The government has set a long-term decontamination goal of reducing individuals’ annual exposure to additional radiation—radiation that does not come from medical procedures or natural sources—to 1 millisievert or lower. This figure is equivalent to 0.23 microsievert in terms of air dose per hour.

In Fukushima Prefecture, 0.23 microsievert is widely perceived to be the maximum tolerable level.

The report said residents should be informed that the decontamination goal will not be set with air doses………

The report went on to say that decontamination efforts based on air doses alone do not always help reduce individuals’ exposure.

For specific steps based on individuals’ radiation doses, the report called on municipalities to check each resident’s radiation levels and streamline the current decontamination work by placing priority on decontaminating locations with higher radiation readings.

It also sought for them to put radiation shields in place and urge residents to stay away from points of high radiation. http://the-japan-news.com/news/article/0001467664

August 2, 2014 - Posted by Christina Macpherson | health, Japan