Electron spin resonance analysis of tooth enamel does not indicate exposures to large radiation doses in a large proportion of distally-exposed A-bomb survivors
| Autor: | Nori Nakamura, Yuko Hirai, Chuzo Miyazawa, Yoshiaki Kodama, Harry M. Cullings |
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| Rok vydání: | 2011 |
| Předmět: |
Molar
Health Toxicology and Mutagenesis Radiation Radiation Dosage law.invention stomatognathic system Japan law medicine Humans Radiology Nuclear Medicine and imaging Electron paramagnetic resonance Dental Enamel Chromosome Aberrations Nuclear Weapons business.industry Chemistry Electron Spin Resonance Spectroscopy Environmental exposure Environmental Exposure Neutron Activation Analysis History 20th Century Tooth enamel Control subjects Radiation exposure medicine.anatomical_structure Direct exposure Nuclear medicine business |
| Zdroj: | Journal of radiation research. 52(5) |
| ISSN: | 1349-9157 |
| Popis: | The atomic bombs in Hiroshima and Nagasaki led to two different types of radiation exposure; one was direct and brief and the other was indirect and persistent. The latter (so-called exposure to residual radiation) resulted from the presence of neutron activation products in the soil, or from fission products present in the fallout. Compared with the doses from direct exposures, estimations of individual doses from residual radiation have been much more complicated, and estimates vary widely among researchers. The present report bases its conclusions on radiation doses recorded in tooth enamel from survivors in Hiroshima. Those survivors were present at distances of about 3 km or greater from the hypocenter at the time of the explosion, and have DS02 estimated doses (direct exposure doses) of less than 5 mGy (and are regarded as control subjects). Individual doses were estimated by measuring CO(2)(-) radicals in tooth enamel with the electron spin resonance (ESR; or electron paramagnetic resonance, EPR) method. The results from 56 molars donated by 49 survivors provided estimated doses which vary from -200 mGy to 500 mGy, and the median dose was 17 mGy (25% and 75% quartiles are -54 mGy and 137 mGy, respectively) for the buccal parts and 13 mGy (25% and 75% quartiles: -49 mGy and 87 mGy, respectively) for the lingual parts of the molars. Three molars had ESR-estimated doses of 300 to 400 mGy for both the buccal and lingual parts, which indicates possible exposures to excess doses of penetrating radiation, although the origin of such radiation remains to be determined. The results did not support claims that a large fraction of distally-exposed survivors received large doses (e.g. 1 Gy) of external penetrating radiation resulting from residual radiation. |
| Databáze: | OpenAIRE |
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