MEXT has reported a radiation reading of 150 μSv/hr 30 km northwest of Fukushima Daiichi nuclear power plant. If you were living there and this rate is sustained for a long period of time, would you have to worry ?
In Canada maximum dosage rates are based on the International Commission on Radiological Protection (ICRP).
Maximum Dose for a Nuclear Energy Worker
If you are a nuclear energy worker, the maximum dose over a five year period is 100 mSv with an additional restriction that the dose in any single year is not to exceed 50 mSv.
With a rate of 0.150 mSv/hr, you would reach 50 mSv in 333 hours, or about 14 days.
Maximum Dose for the General Public
The maximum permissable dose for the general public is one mSv/yr. (This is over and above the dose you get from ambient background radiation.)
With a rate of 0.150 mSv/hr, you would reach the annual maximum dose in about seven hours.
Conclusion
You really don't want to be outside in this level of radiation for an extended period.
The maximum permissible dose for Japanese nuclear workers was 100 mSv per year before the accident at Fukushima Daiichi. Shortly after the accident, the Japanese government increased the annual limit to 250 mSv for emergency situations. The World Health Organization considers 500 mSv/year acceptable for emergency work.
Posted by: Geoff | April 17, 2011 at 02:16 AM