It’s probably 700 microsieverts per year although the Mainichi does not mention that in the article.
– Osaka residents voice radiation concerns over Fukushima-made bridge girders (Mainichi Japan Oct. 7, 2011):
OSAKA — Residents of Kawachinagano in Osaka Prefecture have expressed concerns over radiation from girders made in Fukushima Prefecture, which will be used for a bridge construction project as part of National Route 371’s bypass linking here with Wakayama Prefecture.
The local reaction led Osaka Prefecture to suspend the work in late July to ensure the safety of the steel bridge girders from Fukushima, which has been rocked by the crisis at the Fukushima No. 1 Nuclear Power Plant, by measuring their radiation doses. But because there are no national safety standards for civil engineering materials such as bridge girders, the Osaka Prefectural Government is considering asking the central government to set safety standards for such construction materials at an early date.
According to Osaka’s Tondabayashi civil engineering office, a firm in Koriyama, Fukushima Prefecture, won the order to build and install the bridge girders, each measuring 55 meters in length and 8 meters in width, for about 125 million yen. The bridge girders were manufactured in a factory in Koriyama in February this year and had been kept outdoors on the factory’s premises.
Bridge piers made by another firm were installed in July as part of the bridge construction project, and the Osaka Prefectural Government was scheduled to take delivery of the Fukushima-made bridge girders in September to complete the project in February next year.
But during a briefing by the Tondabayashi civil engineering office for local residents in late July, some residents took issue with possible radiation contamination from the bridge girders and asked the Osaka government to ensure their safety. The prefectural government later received similar messages of serious concern from other residents.
A private inspection entity checked the bridge girders and found the amount of radiation to be 0.7 millisieverts, as compared to an annual limit of 1 millisievert for ordinary residents set by the International Commission on Radiological Protection.
The prefectural government will decide later this year how to deal with the issue after measuring radiation doses at the construction site and consulting with experts. A prefectural government official in charge of the matter said, “There are no national standards for civil engineering materials and there is no way to prove the bridge girders’ safety. We plan to ask the state to draw up national standards.”
Osaka Gov. Toru Hashimoto told reporters on Oct. 6, “We want to release data so as not to cause unjustified harmful rumors.”