ZIA CP010132-10395 (ZIA) | |||
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Title | Study to improve thyroid doses from fallout exposure in Kazakhstan | ||
Institution | NCI, Bethesda, MD | ||
Principal Investigator | Mabuchi, Kiyohiko | NCI Program Director | N/A |
Cancer Activity | N/A | Division | DCEG |
Funded Amount | $578 | Project Dates | 00/00/0000 - 00/00/0000 |
Fiscal Year | 2017 | Project Type | Intramural |
Research Topics w/ Percent Relevance | Cancer Types w/ Percent Relevance | ||
Biochemical Epidemiology (45.0%) Cancer (100.0%) |
Thyroid (100.0%) | ||
Research Type | |||
Cancer-Related Biology
Exogenous Factors in the Origin and Cause of Cancer |
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Abstract | |||
"High thyroid doses from both internal and external radiation sources to individuals exposed during childhood to radioactive fallout from nuclear tests conducted at the Semipalatinsk Nuclear Test Site in Kazakhstan between 1949 and 1962 present a unique opportunity to quantify and compare the two types of radiation dose as risk factors for thyroid disease in a single population. Analyses based on preliminary dose estimates suggest that internal and external exposures independently and significantly contributed to the dose response for thyroid nodules, and that the relative biological effectiveness (RBE) of internal compared to external radiation dose IS about one-third, with wide confidence bounds. The conditions of fallout exposure in Kazakhstan are directly relevant to those following a hypothetical nuclear accident or a radiation terrorism involving high levels of local fallout. New data will be acquired to improve our estimates of internal and external radiation dose and thereby refine our dose-response estimates. Using focus group interviews, we will collect retrospective information about factors influencing radiation dose to the thyroid gland in children of two distinct ethnic groups (Kazakh and European). These factors include milk and milk product consumption, time typically spent outdoors, radiation shielding provided by dwellings and other buildings, and seasonal practices of pasturing and supplemental feeding of dairy animals at the time of the nuclear tests. These data will fill key gaps in the current dosimetry, including (1) milk consumption and related agricultural practices pertinent to internal radiation dose estimation, (2) outdoor activity patterns, shielding from fallout particles and evacuation from villages at the times pertinent to external radiation dose calculations, and (3) evaluation and quantification of dosimetric uncertainty so that it can be taken into account in statistical calculations using recently developed methodologies." |