Health physics
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Radiation protection in pediatric interventional cardiology: An IAEA PILOT program in Latin America.
The aim of this work is to present a methodology and some initial results for a pilot program on radiation protection (RP) in pediatric interventional cardiology under the auspices of the International Atomic Energy Agency. The starting point of the program was a workshop involving several pediatric cardiologists leading this specialty in 11 Latin American countries. The workshop included a pilot RP training course and additional sessions during which the objectives of the program and the methodology to collect and process data on patient and staff radiation doses were discussed. ⋯ A total of 2,429 procedures (50% diagnostic and 50% therapeutic) were carried out during 2009 in these centers. Patient dose data were available in only a few centers and were not analyzed on a regular basis in any of the catheterization laboratories involved. Plans were developed for a basic QC protocol of the x-ray systems and construction of a Latin American database on pediatric cardiology with patient and staff dose values with the idea in mind of obtaining distributions of these dose values before promoting several optimization strategies.
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Historical Article
Chemical and radioactive carcinogens in cigarettes: associated health impacts and responses of the tobacco industry, U.S. Congress, and federal regulatory agencies.
²¹⁰Po and ²¹⁰Pb were discovered in tobacco in 1964. This was followed by detailed assessments of the nature of their deposition, and accompanying dose rates to the lungs of cigarette smokers. Subsequent studies revealed: (1) the sources and pathways through which they gain access to tobacco; (2) the mechanisms through which they preferentially deposit in key segments of the bronchial epithelium; and (3) the fact that the accompanying alpha radiation plays a synergistic role in combination with the chemical carcinogens, to increase the fatal cancer risk coefficient in cigarette smokers by a factor of 8 to 25. ⋯ S. Nuclear Navy. This unnecessary source of lung cancer deaths demands the utmost attention of the radiation protection and public health professions.
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Self-assembled monolayer on mesoporous supports (SAMMS) are hybrid materials created from attachment of organic moieties onto very high surface area mesoporous silica. SAMMS with surface chemistries including three isomers of hydroxypyridinone, diphosphonic acid, acetamide phosphonic acid, glycinyl urea, and diethylenetriamine pentaacetate (DTPA) analog were evaluated for chelation of actinides ((239)Pu, (241)Am, uranium, thorium) from blood. Direct blood decorporation using sorbents does not have the toxicity or renal challenges associated with traditional chelation therapy and may have potential applications for critical exposure cases, reduction of nonspecific dose during actinide radiotherapy, and for sorbent hemoperfusion in renal insufficient patients, whose kidneys clear radionuclides at a very slow rate. ⋯ The excellent efficacy and stability of SAMMS materials in complex biological matrices suggest that SAMMS can also be used as orally administered drugs and for wound decontamination. By changing the organic groups of SAMMS, they can be used not only for actinides but also for other radionuclides. By using the mixture of these SAMMS materials, broad spectrum decorporation of radionuclides is very feasible.
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Historical Article
Radiation doses and cancer risks in the Marshall Islands associated with exposure to radioactive fallout from Bikini and Enewetak nuclear weapons tests: summary.
Nuclear weapons testing conducted at Bikini and Enewetak Atolls during 1946-1958 resulted in exposures of the resident population of the present-day Republic of the Marshall Islands to radioactive fallout. This paper summarizes the results of a thorough and systematic reconstruction of radiation doses to that population, by year, age at exposure, and atoll of residence, and the related cancer risks. Detailed methods and results are presented in a series of companion papers in this volume. ⋯ About 170 excess cancers (radiation-related cases) are projected to occur among more than 25,000 Marshallese, half of whom were born before 1948. All but about 65 of those cancers are estimated to have already been expressed. The 170 excess cancers are in comparison to about 10,600 cancers that would spontaneously arise, unrelated to radioactive fallout, among the same cohort of Marshallese people.
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Radioactive fallout from nuclear test detonations during 1946-1958 at Bikini and Enewetak Atolls in the Marshall Islands (MI) exposed populations living elsewhere in the MI archipelago. A comprehensive analysis, presented in seven companion papers, has produced estimates of tissue-specific radiation absorbed dose to MI residents at all historically inhabited atolls from internal (ingested) and external irradiation resulting from exposure to radioactive fallout, by calendar year, and by age of the population at time of exposure. The present report deals, for the first time, with the implications of these doses for cancer risk among exposed members of the MI population. ⋯ By cancer type, point estimates of attributable risk varied, by location, between 12% and 95% for thyroid cancer, between 2% and 78% for leukemia, and between 0.8% and 55% for all cancers combined. The largest projected risks pertain to the Rongelap Island community and the lowest risks pertain to the populations resident on the southern-most atolls. While the projected cancer risks are smaller than those estimated by the National Cancer Institute in a more simplistic analysis conducted in 2004, these estimates of cancer risk are the best available as they are based on the most detailed dose reconstruction to date and comprehensively include populations at all locations and dose contributions from all nuclear tests.