External Radiation Exposure to the Population of the Continental U.S. from Nevada Weapons Tests and Estimates of Deposition Density of Radionuclides That Could Significantly Contribute to Internal Radiation Exposure via Ingestion (original) (raw)
Related papers
Journal of Environmental Radioactivity, 2004
For the first time, calculations for the more than 3000 counties of the US have been completed that estimate the average deposition density (Bq m À2 ) of more than 40 radionuclides in fallout from atmospheric nuclear weapons tests conducted in the US (1951)(1952)(1953)(1954)(1955)(1956)(1957)(1958)(1959)(1960)(1961)(1962) and 19 radionuclides from tests conducted elsewhere in the world (1952)(1953)(1954)(1955)(1956)(1957)(1958)(1959)(1960)(1961)(1962)(1963). The geographic pattern of deposition across the US, as well as the amount of fallout deposited, varied significantly depending on whether the tests were conducted within or outside of the US. Fallout deposited from the Nevada Test Site (NTS) varied geographically as a result of dispersion and dilution in the atmosphere, the wind patterns following each test, and the occurrence of localized rainfall events. In general, states immediately east of the NTS received the highest deposition from tests conducted there. In contrast, the variation in deposition across the country from global fallout was less than for NTS fallout primarily reflecting variations in annual precipitation across larger regions. Hence, in the eastern and mid-western US, where rainfall is above the national average, higher levels of global fallout were deposited than in the more arid southwestern states. This paper presents a summary of the methods used and findings of our studies on fallout from NTS and global fallout, with emphasis on two of the most important radionuclides, 131 I and 137 Cs. Published by Elsevier Ltd.
Health Physics, 1990
During periods of weapons testing at the Nevada Test Site (NTS) between 1951 and 1958, the Environmental Measurements Laboratory ( E M L ) monitored daily fallout at about 100 sites in the U.S. using gummedfilm collectors. These gummed-film data represent the only comprehensive set of actual measurements of fallout during this period for areas outside the immediate vicinity of the NTS. The measured p activities originally reported by E M L have been reviewed and reevaluated. This reevaluation corrected a number of errors in the original data set and allowed fairly accurate estimates to be made of specific radionuclide depositions from individual NTS shots. Estimates of the geographical and temporal variations in cumulative I3'Cs and '"I depositions from all NTS shots through 1957 are presented, as well as estimates of the relative impact of particular shots and test series. The revised gummed-film estimates of total NTS fallout depositions are compared with estimates based on contemporary and historical soil sample analyses. These reevaluated gummed-film fallout deposition estimates are being extensively utilized in a number of ongoing programs to reconstruct the radiation exposure of the U.S. population from Nevada weapons testing.
Radiation Doses to Local Populations Near Nuclear Weapons Test Sites Worldwide
Health Physics, 2002
Nuclear weapons testing was conducted in the atmosphere at numerous sites worldwide between 1946 and 1980, which resulted in exposures to local populations as a consequence of fallout of radioactive debris. The nuclear tests were conducted by five nations (United States, Soviet Union, United Kingdom, France, and China) primarily at 16 sites. The 16 testing sites, located in nine different countries on five continents (plus Oceania) contributed nearly all of the radioactive materials released to the environment by atmospheric testing; only small amounts were released at a few other minor testing sites. The 16 sites discussed here are Nevada Test Site, USA (North American continent), Bikini and Enewetak, Marshall Islands (Oceania); Johnston Island, USA (Oceania), Christmas and Malden Island, Kiribati (Oceania); Emu Field, Maralinga, and Monte Bello Islands, Australia (Australian continent); Mururoa and Fangataufa, French Polynesia (Oceania), Reggane, Algeria (Africa), Novaya Zemlya and Kapustin Yar, Russia (Europe), Semipalatinsk, Kazakhstan (Asia), and Lop Nor, China (Asia). There were large differences in the numbers of tests conducted at each location and in the total explosive yields. Those factors, as well as differences in population density, lifestyle, environment, and climate at each site, led to large differences in the doses received by local populations. In general, the tests conducted earliest led to the highest individual and population exposures, although the amount of information available for a few of these sites is insufficient to provide any detailed evaluation of radiation exposures. The most comprehensive information for any site is for the Nevada Test Site. The disparities in available information add difficulty to determining the radiation exposures of local populations at each site. It is the goal of this paper to summarize the available information on external and internal doses received by the public living in the regions near each of the mentioned nuclear test sites as a consequence of local fallout deposition. Health Phys. 82(5):706 -725; 2002
Radiation Exposures in Utah from Nevada Nuclear Tests
Science, 1983
From 1951 through 1958, nuclear weapons tests were carried out at the Nevada Test Site (NTS) (Fig. 1). In recent years, concern has developed regarding the impact of fallout from those tests, both in the immediate vicinity of the NTS and in other parts of the United States. Claims have been filed against the government asserting that exposure counties of Lyon et al., by a completely independent method. We used (i) contemporary measurements of residual 137Cs and plutonium in soil samples from undisturbed sites and (ii) in situ gammaspectrometric analyses of '37Cs soil activity. The fraction of the total s37Cs at each site attributable to NTS fallout as opposed to global fallout (that is, fallout Summary. The exposure of the population of Utah to external gamma-radiation from the fallout from nuclear weapons tests carried out between 1951 and 1958 at the Nevada Test Site has been reconstructed from recent measurements of residual cesium-137 and plutoniurm in soil. Although the highest exposures were found in the extreme southwest part of Utah, as expected, the residents of the populous northern valleys around Provo, Salt Lake City, and Ogden received a higher mean dose and a significantly greater population dose (person-rads) than did the residents of most counties closer to the test site. However, population doses from external exposure throughout Utah were far too low to result in any statistically observable health effects.
Health Physics, 2003
Five dose reconstruction projects focusing on historical public exposures from U.S. government nuclear facilities have been completed in the last 12 y (Fernald, Hanford, Nevada Test Site, Oak Ridge, Rocky Flats). Using information available in published reports, doses and excess health risks of the most serious contaminants in each study are compared for representative maximally and typically exposed individuals. For both the representative maximally exposed individual and the representative typically exposed individual, the highest excess risks of cancer incidence were from 131 I released from Hanford, Nevada Test Site, and Oak Ridge and 222 Rn released from Fernald (with central estimates for maximally exposed individuals approaching or exceeding 10 ؊2 ); the lowest risks for both maximally and typically exposed individuals were from 239/240 Pu and carbon tetrachloride released from Rocky Flats. Excess health risks to the representative maximally exposed individual were at or below 10 ؊4 for releases from Rocky Flats. For representative typically exposed individuals, the excess risks from releases of mixed radionuclides in the Clinch River (Oak Ridge), PCBs in East Fork Poplar Creek (Oak Ridge), and both plutonium and carbon tetrachloride released from Rocky Flats were mostly below 10 ؊5 . Health Phys. 84(6):687-697; 2003
Health Physics, 2020
Trinity was the first test of a nuclear fission device. The test took place in south-central New Mexico at the Alamogordo Bombing and Gunnery Range at 05:29 AM on 16 July 1945. This article provides detailed information on the methods that were used in this work to estimate the radiation doses that were received by the population that resided in New Mexico in 1945. The 721 voting precincts of New Mexico were classified according to ecozone (plains, mountains, or mixture of plains and mountains), and size of resident population (urban or rural). Methods were developed to prepare estimates of absorbed doses from a range of 63 radionuclides to five organs or tissues (thyroid, active marrow, stomach, colon, and lung) for representative individuals of each voting precinct selected according to ethnicity (Hispanic, White, Native American, and African American) and age group in 1945 (in utero, newborn, 1-2 y, 3-7 y, 8-12 y, 13-17 y, and adult). Three pathways of human exposure were included: (1) external irradiation from the radionuclides deposited on the ground; (2) inhalation of radionuclide-contaminated air during the passage of the radioactive cloud and, thereafter, of radionuclides transferred (resuspended) from soil to air; and (3) ingestion of contaminated water and foodstuffs. Within the ingestion pathway, 13 types of foods and sources of water were considered. Well established models were used for estimation of doses resulting from the three pathways using parameter values developed from extensive literature review. Because previous experience and calculations have shown that the annual dose delivered during the year following a nuclear test is much greater than the doses received in the years after that first year, the time period that was considered is limited to the first year following the day of the test (16 July 1945). Numerical estimates of absorbed doses, based on the methods described in this article, are presented in a separate article in this issue.
Journal of Radiation Research, 2011
Semipalatinsk Nuclear Testing Site (SNTS), concentrations of artificial radionuclides in edible mushrooms, soils and stones from each area were analyzed by gamma spectrometry. Annual effective doses were calculated for each area from the cesium contamination. Calculated internal effective doses of 137 Cs due to ingestion of mushrooms were 1.8 × 10-1 mSv/year (y) in Gomel city (around CNPP), 1.7 × 10-1 mSv/y in Korosten city (around CNPP), 2.8 × 10-4 mSv/y in Semipalatinsk city, and 1.3 × 10-4 mSv/y in Nagasaki. Calculated external effective doses of 137 Cs were 3.4 × 10-2 mSv/y in Gomel city, 6.2 × 10-2 mSv/y in Korosten city, 2.0 × 10-4 mSv/y in Semipalatinsk city, and 1.3 × 10-4 mSv/y in Nagasaki. Distribution of radionuclides in stones collected beside Lake Balapan (in SNTS) were 241 Am (49.4 ± 1.4 Bq/kg), 137 Cs (406.3 ± 1.7 Bq/kg), 58 Co (3.2 ± 0.5 Bq/kg), and 60 Co (125.9 ± 1.1 and 126.1 ± 1.1 Bq/kg). The present study revealed that dose rates from internal and external exposure around CNPP were not sufficiently low and radiation exposure potency still exists even though current levels are below the public dose limit of 1 mSv/y (ICRP1991). Moreover, parts of the SNTS area may be still contaminated by artificial radionuclides derived from nuclear tests. Long-term follow-up of environmental monitoring around CNPP and SNTS, as well as evaluation of health effects in the population residing around these areas, may contribute to radiation safety with a reduction of unnecessary exposure of residents.
1992
This report describes the Offsite Radiation Safety Program conducted during 1991 by the Environmental Protection Agency`s (EPA`s) Environmental Monitoring Systems Laboratory-Las Vegas. This laboratory operates an environmental radiation monitoring program in the region surrounding the Nevada Test Site (NTS) and at former test sites in Alaska, Colorado, Mississippi, Nevada, and New Mexico. The surveillance program is designed to measure levels and trends of radioactivity, if present, in the environment surrounding testing areas to ascertain whether current radiation levels and associated doses to the general public are in compliance with existing radiation protection standards. The surveillance program additionally has the responsibility to take action to protect the health and well being of the public in the event of any accidental release of radioactive contaminants. Offsite levels of radiation and radioactivity are assessed by sampling milk, water, and air; by deploying thermolumi...
Russian Journal of Ecology, 2008
We determined the association between radionuclide deposition levels from nuclear testing at the Nevada Test Site (NTS) and cancer mortality rates in 513 counties of the Midwestern states of Iowa, Illinois, Kansas, Missouri, and Nebraska. The 10-day cumulative deposition for 54 radionuclides and 1-year cumulative deposition for 19 radionuclides were determined with isotope ratios based on each test and 131 I levels in the 513 counties obtained from the US National Cancer Institute's 131 I fallout study. Deposition calculations were done for each test and each radionuclide. Age-adjusted cancer mortality rates for 84 organ-gender combinations for the periods 1950-1959, 1960-1969, 1970-1979, and 1979-1995 were used. Analyses included permutationbased randomization tests for Spearman rank correlation (adjusted for multiple testing). Age-adjusted cancer mortality rates for connective and soft tissue sarcoma, thymus, and female lymphosarcoma and cancer of the colon, brain, thyroid, and uterus were significantly correlated with total fallout and total precipitation during 1951-1957 and 1962. 187 W had the highest cumulative deposition density at 10 days postshot (2783 MBq/m 2 ) among the NTS radionuclides considered. The most significant correlations were observed for 10-day cumulative deposition density of 181 W, 185 W, 54 Mn, 187 W, 24 Na, 185 W, 199 Au, 7 Be, 60 Co, and deposition density of 185 W, 54 Mn, 7 Be, and 60 Co present at 1-year with mortality for cancers such as female connective and soft tissue sarcoma, male and female thymus, female colon, male and female thyroid, female brain, male multiple myeloma, female breast, and uterine cancer. Significant correlations included isotopic forms of mutagenic metals such as antimony, beryllium, cadmium, cobalt, cesium, manganese, rhodium, selenium, tellurium, and tungsten. The large number of significant correlation tests beyond expectation warrants deeper questions related to the toxicology of fission products and induced radionuclides, validity of kriging procedures, and new studies on core sampling of watersheds and trees in regions assumed to receive the greatest levels of environmental radiocontamination.
Worldwide Dispersion and Deposition of Radionuclides Produced in Atmospheric Tests
Health Physics, 2002
Radionuclides produced in atmospheric nuclear tests were widely dispersed in the global environment. From the many measurements of the concentrations in air and the deposition amounts, much was learned of atmospheric circulation and environmental processes. Based on these results and the reported fission and total yields of individual tests, it has been possible to devise an empirical model of the movement and residence times of particles in the various atmospheric regions. This model, applied to all atmospheric weapons tests, allows extensive calculations of air concentrations and deposition amounts for the entire range of radionuclides produced throughout the testing period. Especially for the shorter-lived fission radionuclides, for which measurement results at the time of the tests are less extensive, a more complete picture of levels and isotope ratios can be obtained, forming a basis for improved dose estimations. The contributions to worldwide fallout can be inferred from individual tests, from tests at specific sites, or by specific countries. Progress was also made in understanding the global hydrological and carbon cycles from the tritium and 14 C measurements. A review of the global measurements and modeling results is presented in this paper. In the future, if injections of materials into the atmosphere occur, their anticipated motions and fates can be predicted from the knowledge gained from the fallout experience.