Terrestrial radiation and cancer mortality in Japan...Relation between terrestrial- and cancer...
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Terrestrial radiation and cancer mortality in Japan Imanaka T. September 7, 2010
Transcript of Terrestrial radiation and cancer mortality in Japan...Relation between terrestrial- and cancer...
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Terrestrial radiation and cancer mortality in Japan
Imanaka T.September 7, 2010
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Terrestrial radionuclides
Geochemical map of Japan, AIST HP 2
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Natural radiation: terrestrial origin
Geochemical map of Japan, AIST HPGamma-ray radiation rate at 1 m above ground:D(Gy/h）＝5.4U(ppm)＋2.7Th(ppm)＋13.0K(%) HASL-258(1972)
Example：Hiroshima U：2.4ppm、Th:14.3ppm、K：2.4％13 Gy/h (U) + 39 Gy/h (Th) + 30 Gy/h (K) → 83 Gy/h 3
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Terrestrial -radiation in Japan
Minato, J Geography, 2006
4
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Natural radiation other than terrestrial
Natural radiation in Japan: 1.5 mSv/year
0.4
0.41 0.29
0.38TerrestrialCosmicInternalRadon
5
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Cancer mortality in Japan: total cancer
National Cancer Center HP
Male Female
6
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Cancer mortality in Japan: leukemia
National Cancer Center HP
Male Female
7
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Cancer mortality in Japan: lung, breast
National Cancer Center HP
Male lung Female breast
8
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Relation between terrestrial- and cancer mortality
Total cancer
0
50
100
150
20 40 60 80
Gamma-ray radiation rate, nGy/h
Dea
ths
per 1
05 p
erso
n-ye
ar
MaleFemale
9
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Relation between terrestrial- and cancer mortality
Leukemia
0
2
4
6
8
10
20 40 60 80
Gamma-ray radiation rate, nGy/h
Dea
ths
per 1
05 p
erso
n-ye
ar
MaleFemale
10
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Relation between terrestrial- and cancer mortality
Leukemia
FukuokaOita
Kumamoto Saga
Okinawa KagoshimaMiyazaki
Nagasaki
0
2
4
6
8
10
20 40 60 80
Gamma-ray radiation rate, nGy/h
Dea
ths
per 1
05 p
erso
n-ye
ar
MaleFemale
Closed circles are prefectures in Kyushu island and Okinawa.11
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Relation between terrestrial- and cancer mortality
Male lung cancer and female breast cancer
0
10
20
30
40
20 40 60 80
Gamma-ray radiation rate, nGy/h
Dea
ths
per 1
05 p
erso
n-ye
ar
Male lungFemale breast
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Natural and medical radiation in Japan
2.25 1.48
0.38
0.41
0.4
0.29
Terrestrial
Cosmic
Internal
Radon
Medical Natural
Natural radiation
mSv/year
Data by Radiation Effects Foundation13
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Summary
• Preliminary analysis by Imanaka failed to indicate a relationship between terrestrial radiation and cancer mortality in Japan.
• Considering the natural radiation of 1.5 mSv/yr for 130 million population and the cancer risk factor of 0.05 /Sv, about 10,000 cancer deaths are expected annually due to natural radiation, which corresponds to 3 % of total cancer deaths in Japan.
• If the real risk factor is 10 times larger than the above, 30 % will be due to natural radiation.
• The study by Tondel is interesting and worthy to be challenged.
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