Relation between terrestrial- and cancer mortality
100
5
Deaths per 10 person-year
150
50
Male Female 0 20
40
60
80
Gamma-ray radiation rate, nGy/h
Total cancer 9
Relation between terrestrial- and cancer mortality Male Female
8
6
5
Deaths per 10 person-year
10
4
2
0 20
40
60
80
Gamma-ray radiation rate, nGy/h
Leukemia 10
Relation between terrestrial- and cancer mortality Male Female
8
Nagasaki Miyazaki Kagoshima Okinawa
6
Kumamoto Oita
5
Deaths per 10 person-year
10
Saga
Fukuoka
4
2
0 20
40
60
80
Gamma-ray radiation rate, nGy/h
Leukemia Closed circles are prefectures in Kyushu island and Okinawa. 11
Relation between terrestrial- and cancer mortality
5
Deaths per 10 person-year
40
Male lung Female breast 30
20
10
0 20
40
60
80
Gamma-ray radiation rate, nGy/h
Male lung cancer and female breast cancer
12
Natural and medical radiation in Japan Natural radiation Medical 2.25
Natural 1.48
0.38
Terrestrial
0.29
Cosmic
0.41
0.4
Internal Radon
mSv/year Data by Radiation Effects Foundation 13
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. 14
