Publications by authors named "Takehiro Mitsuguchi"
Article Synopsis
- Radionuclides from 20th-century nuclear activities significantly impacted earth's surface environments, especially in tropical and subtropical shallow-water corals, which record these changes in their skeletons.
- A study of coral from Rowley Shoals shows distinct time series records of iodine (I/I) and carbon (ΔC) levels, revealing increases linked to U.S. atmospheric nuclear tests, particularly between 1955 and the late 1970s.
- The data suggest that the I/I ratio serves as a more reliable indicator of anthropogenic influence in ocean waters compared to ΔC, due to natural dilution processes affecting carbon more significantly.
Tritium concentrations in Japanese precipitation samples collected after the March 2011 accident at the Fukushima Dai-ichi Nuclear Power Plant (FNPP1) were measured. Values exceeding the pre-accident background were detected at three out of seven localities (Tsukuba, Kashiwa and Hongo) southwest of the FNPP1 at distances varying between 170 and 220 km from the source. The highest tritium content was found in the first rainfall in Tsukuba after the accident; however concentrations were 500 times less than the regulatory limit for tritium in drinking water.
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