Impact on ambient dose rate in metropolitan Tokyo from the Fukushima Daiichi Nuclear Power Plant accident

Publication date: July 2016
Source:Journal of Environmental Radioactivity, Volumes 158–159
Author(s): Kazumasa Inoue, Hiroshi Tsuruoka, Tan Van Le, Moeko Arai, Kyoko Saito, Masahiro Fukushi
A car-borne survey was made in metropolitan Tokyo, Japan, in December 2014 to estimate external dose. This survey was conducted for all municipalities of Tokyo and the results were compared with measurements done in 2003. The ambient dose rate measured in the whole area of Tokyo in December 2014 was 60 nGy h⁻¹ (23–142 nGy h⁻¹), which was 24% higher than the rate in 2003. Higher dose rates (>70 nGy h⁻¹) were observed on the eastern and western ends of Tokyo; furthermore, the contribution ratio from artificial radionuclides (¹³⁴Cs and ¹³⁷Cs) to ambient dose rate in eastern Tokyo was twice as high as that of western Tokyo. Based on the measured ambient dose rate, the effective dose rate after the accident was estimated to be 0.45 μSv h⁻¹ in Tokyo. This value was 22% higher than the value before the accident as of December 2014.



from Radiology via xlomafota13 on Inoreader http://ift.tt/1Wa8HW4
via IFTTT