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Nationwide in-situ measurements of terrestrial gamma ray dose rates have been carried out using a scintillation counter. A database of over 4300 entries has been compiled by adding data taken from literature to the data collected by the mentioned survey. A contour map of dose rates in Japan calculated from the database is presented along with a table of dose rates for each bedrock type.
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Susumu MINATO (2006) studied this question.
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