title: Internal exposure to neutron-activated56Mn dioxide powder in Wistar rats: part 1: dosimetry.
abstract: There were two sources of ionizing irradiation after the atomic bombings of Hiroshima and Nagasaki: (1) initial gamma-neutron irradiation at the moment of detonation and (2) residual radioactivity. Residual radioactivity consisted of two components: radioactive fallout containing fission products, including radioactive fissile materials from nuclear device, and neutron-activated radioisotopes from materials on the ground. The dosimetry systems DS86 and DS02 were mainly devoted to the assessment of initial radiation exposure to neutrons and gamma rays, while only brief considerations were given for the estimation of doses caused by residual radiation exposure. Currently, estimation of internal exposure of atomic bomb survivors due to dispersed radioactivity and neutron-activated radioisotopes from materials on the ground is a matter of some interest, in Japan. The main neutron-activated radionuclides in soil dust were24Na,28Al,31Si,32P,38Cl,42K,45Ca,46Sc,56Mn,59Fe,60Co, and134Cs. The radionuclide56Mn (T1/2= 2.58 h) is known as one of the dominant beta- and gamma emitters during the first few hours after neutron irradiation of soil and other materials on ground, dispersed in the form of dust after a nuclear explosion in the atmosphere. To investigate the peculiarities of biological effects of internal exposure to56Mn in comparison with external gamma irradiation, a dedicated experiment with Wistar rats exposed to neutron-activated56Mn dioxide powder was performed recently by Shichijo and coworkers. The dosimetry required for this experiment is described here. Assessment of internal radiation doses was performed on the basis of measured56Mn activity in the organs and tissues of the rats and of absorbed fractions of internal exposure to photons and electrons calculated with the MCNP-4C Monte Carlo using a mathematical rat phantom. The first results of this international multicenter study show that the internal irradiation due to incorporated56Mn powder is highly inhomogeneous, and that the most irradiated organs of the experimental animals are: large intestine, small intestine, stomach, and lungs. Accumulated absorbed organ doses were 1.65, 1.33, 0.24, 0.10 Gy for large intestine, small intestine, stomach, and lungs, respectively. Other organs were irradiated at lower dose levels. These results will be useful for interpretation of the biological effects of internal exposure of experimental rats to powdered56Mn as observed by Shichijo and coworkers.
authors.affiliation: Medical Radiological Research Center (MRRC) named after A.F. Tsyb - National Medical Research Radiological Center of the Health Ministry of the Russian Federation, Koroliova Str. 4, Obninsk, Kaluga Region, 249036, Russian Federation. mrrc@mrrc.obninsk.ru.
authors.forename: Valeriy
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authors.lastname: Stepanenko
authors.affiliation: Semey State Medical University, Kazakhstan, Abay Str., 103, Semey, 071400, Republic of Kazakhstan.
authors.forename: Tolebay
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authors.lastname: Rakhypbekov
authors.affiliation: Hiroshima University, 1-2-3, Kasumi, Minami-ku, Hiroshima, 734-8551, Japan.
authors.forename: Keiko
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authors.lastname: Otani
authors.affiliation: Hiroshima University, 1-2-3, Kasumi, Minami-ku, Hiroshima, 734-8551, Japan.
authors.forename: Satoru
authors.initials: S
authors.lastname: Endo
authors.affiliation: Hiroshima University, 1-2-3, Kasumi, Minami-ku, Hiroshima, 734-8551, Japan.
authors.forename: Kenichi
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authors.lastname: Satoh
authors.affiliation: Hiroshima University, 1-2-3, Kasumi, Minami-ku, Hiroshima, 734-8551, Japan.
authors.forename: Noriyuki
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authors.lastname: Kawano
authors.affiliation: Nagasaki University, 1-12-4, Sakamoto, Nagasaki, 852-8102, Japan.
authors.forename: Kazuko
authors.initials: K
authors.lastname: Shichijo
authors.affiliation: Nagasaki University, 1-12-4, Sakamoto, Nagasaki, 852-8102, Japan.
authors.forename: Masahiro
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authors.lastname: Nakashima
authors.affiliation: Nagasaki University, 1-12-4, Sakamoto, Nagasaki, 852-8102, Japan.
authors.forename: Toshihiro
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authors.lastname: Takatsuji
authors.affiliation: University of Tsukuba, 1-1-1, Tsukuba-shi Tennodai, Ibaraki, 305-8571, Japan.
authors.forename: Aya
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authors.lastname: Sakaguchi
authors.affiliation: University of Tsukuba, 1-1-1, Tsukuba-shi Tennodai, Ibaraki, 305-8571, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Kato
authors.affiliation: University of Tsukuba, 1-1-1, Tsukuba-shi Tennodai, Ibaraki, 305-8571, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Onda
authors.affiliation: Hiroshima University, 1-2-3, Kasumi, Minami-ku, Hiroshima, 734-8551, Japan.
authors.forename: Nariaki
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authors.lastname: Fujimoto
authors.affiliation: Okayama University of Science, 1-1, Kitaku Ridai-cho, Kita-ku, Okayama, 700-0005, Japan.
authors.forename: Shin
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authors.lastname: Toyoda
authors.affiliation: Ibaraki Prefectural University of Health Science, 4669-2, Ami-chyo Ami, Inashiki-gun, Ibaraki, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Sato
authors.affiliation: Semey State Medical University, Kazakhstan, Abay Str., 103, Semey, 071400, Republic of Kazakhstan.
authors.forename: Altay
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authors.affiliation: Semey State Medical University, Kazakhstan, Abay Str., 103, Semey, 071400, Republic of Kazakhstan.
authors.forename: Nailya
authors.initials: N
authors.lastname: Chaizhunusova
authors.affiliation: Semey State Medical University, Kazakhstan, Abay Str., 103, Semey, 071400, Republic of Kazakhstan.
authors.forename: Nurlan
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authors.lastname: Sayakenov
authors.affiliation: Semey State Medical University, Kazakhstan, Abay Str., 103, Semey, 071400, Republic of Kazakhstan.
authors.forename: Darkhan
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authors.lastname: Uzbekov
authors.affiliation: Semey State Medical University, Kazakhstan, Abay Str., 103, Semey, 071400, Republic of Kazakhstan.
authors.forename: Aisulu
authors.initials: A
authors.lastname: Saimova
authors.affiliation: Semey State Medical University, Kazakhstan, Abay Str., 103, Semey, 071400, Republic of Kazakhstan.
authors.forename: Dariya
authors.initials: D
authors.lastname: Shabdarbaeva
authors.affiliation: National Nuclear Center of the Republic of Kazakhstan, Krasnoarmeyskaya Str., 2, Build 54 B, 071100, Kurchatov, Republic of Kazakhstan.
authors.forename: Mazhin
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authors.lastname: Skakov
authors.affiliation: National Nuclear Center of the Republic of Kazakhstan, Krasnoarmeyskaya Str., 2, Build 54 B, 071100, Kurchatov, Republic of Kazakhstan.
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authors.initials: A
authors.lastname: Vurim
authors.affiliation: National Nuclear Center of the Republic of Kazakhstan, Krasnoarmeyskaya Str., 2, Build 54 B, 071100, Kurchatov, Republic of Kazakhstan.
authors.forename: Vyacheslav
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authors.lastname: Gnyrya
authors.affiliation: National Nuclear Center of the Republic of Kazakhstan, Krasnoarmeyskaya Str., 2, Build 54 B, 071100, Kurchatov, Republic of Kazakhstan.
authors.forename: Almas
authors.initials: A
authors.lastname: Azimkhanov
authors.affiliation: National Nuclear Center of the Republic of Kazakhstan, Krasnoarmeyskaya Str., 2, Build 54 B, 071100, Kurchatov, Republic of Kazakhstan.
authors.forename: Alexander
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authors.lastname: Kolbayenkov
authors.affiliation: Eurasian National University named after L.N. Gumilyov, Munaipasova Str. 13, Astana, 010008, Republic of Kazakhstan.
authors.forename: Kasym
authors.initials: K
authors.lastname: Zhumadilov
authors.affiliation: Semey State Medical University, Kazakhstan, Abay Str., 103, Semey, 071400, Republic of Kazakhstan.
authors.forename: Yankar
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authors.lastname: Kairikhanova
authors.affiliation: Medical Radiological Research Center (MRRC) named after A.F. Tsyb - National Medical Research Radiological Center of the Health Ministry of the Russian Federation, Koroliova Str. 4, Obninsk, Kaluga Region, 249036, Russian Federation.
authors.forename: Andrey
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authors.affiliation: Medical Radiological Research Center (MRRC) named after A.F. Tsyb - National Medical Research Radiological Center of the Health Ministry of the Russian Federation, Koroliova Str. 4, Obninsk, Kaluga Region, 249036, Russian Federation.
authors.forename: Vsevolod
authors.initials: V
authors.lastname: Galkin
authors.affiliation: Medical Radiological Research Center (MRRC) named after A.F. Tsyb - National Medical Research Radiological Center of the Health Ministry of the Russian Federation, Koroliova Str. 4, Obninsk, Kaluga Region, 249036, Russian Federation.
authors.forename: Sergey
authors.initials: S
authors.lastname: Ivanov
authors.affiliation: Medical Radiological Research Center (MRRC) named after A.F. Tsyb - National Medical Research Radiological Center of the Health Ministry of the Russian Federation, Koroliova Str. 4, Obninsk, Kaluga Region, 249036, Russian Federation.
authors.forename: Timofey
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authors.affiliation: Medical Radiological Research Center (MRRC) named after A.F. Tsyb - National Medical Research Radiological Center of the Health Ministry of the Russian Federation, Koroliova Str. 4, Obninsk, Kaluga Region, 249036, Russian Federation.
authors.forename: Aleksey
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authors.lastname: Petukhov
authors.affiliation: Medical Radiological Research Center (MRRC) named after A.F. Tsyb - National Medical Research Radiological Center of the Health Ministry of the Russian Federation, Koroliova Str. 4, Obninsk, Kaluga Region, 249036, Russian Federation.
authors.forename: Elena
authors.initials: E
authors.lastname: Yaskova
authors.affiliation: Medical Radiological Research Center (MRRC) named after A.F. Tsyb - National Medical Research Radiological Center of the Health Ministry of the Russian Federation, Koroliova Str. 4, Obninsk, Kaluga Region, 249036, Russian Federation.
authors.forename: Irina
authors.initials: I
authors.lastname: Belukha
authors.affiliation: Medical Radiological Research Center (MRRC) named after A.F. Tsyb - National Medical Research Radiological Center of the Health Ministry of the Russian Federation, Koroliova Str. 4, Obninsk, Kaluga Region, 249036, Russian Federation.
authors.forename: Artem
authors.initials: A
authors.lastname: Khailov
authors.affiliation: Medical Radiological Research Center (MRRC) named after A.F. Tsyb - National Medical Research Radiological Center of the Health Ministry of the Russian Federation, Koroliova Str. 4, Obninsk, Kaluga Region, 249036, Russian Federation.
authors.forename: Valeriy
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authors.lastname: Skvortsov
authors.affiliation: Medical Radiological Research Center (MRRC) named after A.F. Tsyb - National Medical Research Radiological Center of the Health Ministry of the Russian Federation, Koroliova Str. 4, Obninsk, Kaluga Region, 249036, Russian Federation.
authors.forename: Alexander
authors.initials: A
authors.lastname: Ivannikov
authors.affiliation: Medical Radiological Research Center (MRRC) named after A.F. Tsyb - National Medical Research Radiological Center of the Health Ministry of the Russian Federation, Koroliova Str. 4, Obninsk, Kaluga Region, 249036, Russian Federation.
authors.forename: Umukusum
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authors.lastname: Akhmedova
authors.affiliation: Medical Radiological Research Center (MRRC) named after A.F. Tsyb - National Medical Research Radiological Center of the Health Ministry of the Russian Federation, Koroliova Str. 4, Obninsk, Kaluga Region, 249036, Russian Federation.
authors.forename: Viktoria
authors.initials: V
authors.lastname: Bogacheva
authors.affiliation: Hiroshima University, 1-2-3, Kasumi, Minami-ku, Hiroshima, 734-8551, Japan.
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mesh_terms: D000818:Animals; D017895:Manganese Compounds / Q000737:chemistry* / Q000378:metabolism*; D009502:Neutrons; D010087:Oxides / Q000737:chemistry* / Q000378:metabolism*; D011208:Powders; D011829:Radiation Dosage; D011851:Radioactivity; D011868:Radioisotopes; D011874:Radiometry; D051381:Rats; D017208:Rats, Wistar
chemical_list: D017895:Manganese Compounds; D010087:Oxides; D011208:Powders; D011868:Radioisotopes; C016552:manganese dioxide
keywords: 56Mn; Experimental rats; Internal dosimetry; Monte Carlo simulation; Neutron activation; Radioactive dust