Radiation levels in Koriyama children exceed annual limit: survey, Mainichi Daily News, Dec. 9, 2011:
Radiation levels detected in children in this city [Koriyama, 60 km from meltdowns ...] exceed the government-set annual limit, a municipal government study has revealed.
- Survey results [...] reported to parents individually on Dec. 8
- First of three to be conducted before March 2012
- Examined accumulated radiation levels in all 25,551 elementary and middle school children residing in the city
- Measured on a 24-hour basis daily
- Between the period of Oct. 5 and Nov. 6
- Final survey data excludes the 0.06 millisieverts dosage presumed to be accumulated through natural exposure to radiation
- Average radiation level [...] was 0.12 millisieverts [in 31 days]
- Which calculated over a one-year period equals 1.33 millisieverts
- 0.33 millisieverts more than the annual limit set by the government [1 millisievert]
- 94 percent had radiation doses below 0.2 millisieverts
- The highest dose found in four children equals 4.98 millisieverts when calculated over a one-year term [...] almost five times the annual limit
“We hope this survey data will help people take action to decrease their radiation exposure levels by comparing it to their individual daily records” -Official at the Koriyama Municipal Board of Education.
All of following groups have concluded the results “pose no harm to the children’s health”:
- Officials at the Koriyama Municipal Government
- Toshiteru Okubo, the board chairman of the Radiation Effects Research Foundation
- Other radiation experts serving as nuclear measures advisors to the city
One question remains Mainichi — the source of some of the better reporting coming out of Japan on Fukushima — did the survey record internal radiation, external, both? Presumably external, as the article says radiation was “measured on a 24-hour basis daily”, leading to the assumption that a dosimeter was used for the survey measurements. Dosimeters only measure external radiation. So the study appears to only be measuring the children’s external radiation dose. Does Mainichi consider this relevant?
Published: December 9th, 2011 at 1:30 pm ET