Radioactive strontium in Yokohama apparently unrelated to Fukushima, Kyodo, Nov. 25, 2011 (Emphasis Added):
The science ministry said Thursday that radioactive strontium detected in sediment in Yokohama appears to be unconnected to the nuclear crisis [...]
The ministry tested sediment collected at two locations in Yokohama’s Kohoku Ward by the city office and soil in the neighborhood but did not detect strontium 89 with a half-life period of around 50 days, which would have been detected if the incident was related to the Fukushima nuclear crisis.
Strontium-89 in Yokohama detected in Mid-October
In a test conducted by the Isotope Research Institute in Yokohama at the request of the city office, the private institute measured both strontium 89 and strontium 90, and detected 59 to 129 becquerels per kg of strontium.
Regarding the significant difference in figures detected by the ministry and the institute, the ministry said the institute’s test may have also detected radium and other radioactive substances [??? Does this explain the presence of Strontium-89?] not related to a nuclear plant accident.
Kyodo also notes the recent Strontium at several places in Tokyo
Meanwhile, radioactive strontium has been detected in soil samples taken from three locations in downtown Tokyo, a citizens’ group said Thursday.
Soil collected from outside the Ministry of Economy, Trade and Industry, and the Tokyo International Forum, both in Chiyoda Ward, and the Kiyosumi-Shirakawa subway station in Koto Ward measured 48, 51 and 44 becquerels per kg [...]
The Tokyo amount of strontium-89 has yet to be determined, via EX-SKF:
Iwakami cautions that radioactive strontium may be confirmed to have come from Fukushima only after the detailed analysis at a laboratory that can separately measure strontium-89 and strontium-90. [...] I believe there is only one or two laboratories in Japan that does that; one of them is the laboratory that TEPCO uses for the radionuclide analysis (Japan Chemical Analysis Center).
Published: November 25th, 2011 at 12:30 pm ET