Average annual radiation dosage reduced to 0.82 mSv in Date city

28 August 2015

The city of Date released on Aug. 27 results of its year-long survey from July 2014 of external radiation exposure for 11,350 residents. The annual additional radiation dosage in areas with relatively high aerial radiation levels (Zone A) averaged 0.8 millisievert, falling below the 1-millisievert line set by the central government as a long-term goal for decontamination.

Those covered by the survey included all children up to 15 years old and all pregnant women in the city, as well as all residents in Zone A. In neighboring Zone B and in other areas falling under Zone C, residents picked by the city government, as well as those who opted for the survey, were also covered. Of the total of about 16,000 participants, data were collected from 11,350 people wearing badge-type dosimeters.

The actual radiation dosages from each of the zones are shown in the accompanying graph. In Zone A, which includes government-designated areas where residents are recommended to remain evacuated, the average annual additional radiation dosage was 1.00 millisievert last year and 1.59 millisievert two years ago. The figures have also declined in B and C zones.

“This is a reflection of the natural decrease in airborne radiation levels and results of decontamination work,” said Date Mayor Shoji Nishida. The city plans to continue conducting the survey.

(Translated by Kyodo News)