What maximum radiation is allowable?

 April 18, 2014

Allowable radiation exposure levels

http://www3.nhk.or.jp/nhkworld/english/news/20140418_46.html

The Japanese government has set the maximum annual allowable radiation exposure at 20 millisieverts to let evacuees return to the areas near the Fukushima Daiichi nuclear power plant.

The International Commission on Radiological Protection, or ICRP, says annual exposure levels that necessitate evacuation should be set between 20 and 100 millisieverts.

A lifetime exposure to 100 millisieverts of radiation is thought to increase the risk of death from cancer by 0.5 percent.

The government says it adopted the highest ICRP standard.

But the ICRP says that in the long term the levels should be set between 20 millisieverts and as low as one millisievert -- the allowable amount in one year for a person in ordinary circumstances.

The government says it wants to achieve the long-term goal of reducing exposure to less than one millisievert for people near Fukushima Daiichi by removing radioactive materials from the soil and taking other measures.

Apr. 18, 2014 - Updated 12:32 UTC