The assessment of radiation exposures in native American communities from nuclear weapons testing in Nevada (original) (raw)
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Native American Exposure to Iodine-131 from Nuclear Weapons Testing in Nevada
2004
A great deal of work has been done reconstructing doses from Nevada Test Site fallout, yet the unique exposures of Native American communities continue to be neglected. It is possible to estimate the exposures of these communities through a process of collaborative information gathering and analysis. This paper builds on a previous exercise that demonstrated the substantial doses received through the consumption of contaminated game. The updated model includes new information on the deposition of iodine-131, an assessment of the neonatal thyroid doses received through breast milk, an exploration of the effect of population mobility on dose estimates, and estimates of thyroid cancer risk. All thyroid dose estimates from the rabbit exposure pathway are comparable in magnitude to National Cancer Institute comprehensive dose estimates that assume exposure to contaminated milk from backyard cows and goats. Dose estimates from the rabbit exposure pathway are larger than estimated doses fr...
Health Physics
The Trinity nuclear test was detonated in south-central New Mexico on 16 July 1945; in the early 2000s, the National Cancer Institute undertook a dose and cancer risk projection study of the possible health impacts of the test. In order to conduct a comprehensive dose assessment for the Trinity test, we collected diet and lifestyle data relevant to the populations living in New Mexico around the time of the test. This report describes the methodology developed to capture the data used to calculate radiation exposures and presents dietary and lifestyle data results for the main exposure pathways considered in the dose reconstruction. Individual interviews and focus groups were conducted in 2017 among older adults who had lived in the same New Mexico community during the 1940s or 1950s. Interview questions and guided group discussions focused on specific aspects of diet, water, type of housing, and time spent outdoors for different age groups. Thirteen focus groups and 11 individual interviews were conducted among Hispanic, White, and Native American participants. Extensive written notes and audio recordings aided in the coding of all responses used to derive ranges, prevalence, means, and standard deviations for each exposure variable for various age categories by region and ethnicity. Children aged 11-15 y in 1940s or 1950s from the rural plains had the highest milk intakes (993 mL d −1), and lowest intakes were among 11-to 15-y-olds in mountainous regions (191 mL d −1). Lactose intolerance rates were 7-71%, and prevalence was highest among Native Americans. Meat was not commonly consumed in the summer in most communities, and if consumed, it was among those aged 11-15 y of age or older who had relatively small amounts of 100-200 g d −1. Most drinking and cooking water came from covered wells, and most homes were made of adobe, which provided more protection from external radiation than wooden structures. The use of multiple approaches to trigger memory and collect participant reports on diet and other factors from the distant past seemed effective. These data were summarized, and together with other information, these data have been used to estimate radiation doses for representative persons of all ages in the main ethnic groups residing in New Mexico at the time of the Trinity nuclear test.
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.
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
1999
This report provides estimates of the external radiation exposure and whole-body effective dose received by residents of the continental U.S. during the period 1951-1962 from weapons tests carried out at the Nevada Test Site (NTS). Estimates are given on a county-by-county basis for each test and for each year of testing. The average committed population dose from all NTS tests was about 0.5 mSv, about equivalent to 1-2 years of external radiation exposure from natural background. Residents of the counties immediately downwind from the NTS incurred much higher doses, in excess of 3 mSv, while the residents of the Far West, Pacific Northwest and Southeast received lower than average exposures. The tests and radionuclides that contributed the most exposure are discussed, as well as the dependence on fallout time of arrival. The most exposed individuals were outdoor workers; the least exposed were persons who spent most of their time indoors in heavily constructed buildings.
Estimated Radiation Doses Received by New Mexico Residents from the 1945 Trinity Nuclear Test
Health Physics
The National Cancer Institute study of projected health risks to New Mexico residents from the 1945 Trinity nuclear test provides best estimates of organ radiation absorbed doses received by representative persons according to ethnicity, age, and county. Doses to five organs/tissues at significant risk from exposure to radioactive fallout (i.e., active bone marrow, thyroid gland, lungs, stomach, and colon) from the 63 most important radionuclides in fresh fallout from external and internal irradiation were estimated. The organ doses were estimated for four resident ethnic groups in New Mexico (Whites, Hispanics, Native Americans, and African Americans) in seven age groups using: (1) assessment models described in a companion paper, (2) data on the spatial distribution and magnitude of radioactive fallout derived from historical documents, and (3) data collected on diets and lifestyles in 1945 from interviews and focus groups conducted in 2015-2017 (described in a companion paper). The organ doses were found to vary widely across the state with the highest doses directly to the northeast of the detonation site and at locations close to the center of the Trinity fallout plume. Spatial heterogeneity of fallout deposition was the largest cause of variation of doses across the state with lesser differences due to age and ethnicity, the latter because of differences in diets and lifestyles. The exposure pathways considered included both external irradiation from deposited fallout and internal irradiation via inhalation of airborne radionuclides in the debris cloud as well as resuspended ground activity and ingestion of contaminated drinking water (derived both from rivers and rainwater cisterns) and foodstuffs including milk products, beef, mutton, and pork, human-consumed plant products including leafy vegetables, fruit vegetables, fruits, and berries. Tables of best estimates of county population-weighted average organ doses by ethnicity and age are presented. A discussion of our estimates of uncertainty is also provided to illustrate a lower and upper credible range on our best estimates of doses. Our findings indicate that only small geographic areas immediately downwind to the northeast received exposures of any significance as judged by their magnitude relative to natural radiation. The findings presented are the most comprehensive and well-described estimates of doses received by populations of New Mexico from the Trinity nuclear test.
Health Physics, 2010
Annual internal radiation doses resulting from both acute and chronic intakes of all important dose-contributing radionuclides occurring in fallout from nuclear weapons testing at Bikini and Enewetak from 1946 through 1958 have been estimated for the residents living on all atolls and separate reef islands of the Marshall Islands. Internal radiation absorbed doses to the tissues most at risk to cancer induction (red bone marrow, thyroid, stomach, and colon) have been estimated for representative persons of all population communities for all birth years from 1929 through 1968, and for all years of exposure from 1948 through 1970. The acute intake estimates rely on a model using, as its basis, historical urine bioassay data, for members of the Rongelap Island and Ailinginae communities as well as for Rongerik residents. The model also utilizes fallout times of arrival and radionuclide deposition densities estimated for all tests and all atolls. Acute intakes of 63 radionuclides were estimated for the populations of the 20 inhabited atolls and for the communities that were relocated during the testing years for reasons of safety and decontamination. The model used for chronic intake estimates is based on reported whole-body, urine, and blood counting data for residents of Utrik and Rongelap. Dose conversion coefficients relating intake to organ absorbed dose were developed using internationally accepted models but specifically tailored for intakes of particulate fallout by consideration of literature-based evidence to choose the most appropriate alimentary tract absorption fraction (f 1 ) values. Dose estimates were much higher for the thyroid gland than for red marrow, stomach wall, or colon. The highest thyroid doses to adults were about 7,600 mGy for the people exposed on Rongelap; thyroid doses to adults were much lower, by a factor of 100 or more, for the people exposed on the populated atolls of Kwajalein and Majuro. The estimates of radionuclide intake and internal radiation dose to the Marshallese that are presented in this paper are the most complete available anywhere and were used to make projections of lifetime cancer risks to the exposed populations, which are presented in a companion paper in this volume. Health Phys. 99(2):157-200; 2010
Thyroid Cancer Rates and 131I Doses From Nevada Atmospheric Nuclear Bomb Tests
Journal of The National Cancer Institute, 1998
Background: We examined data on death from thyroid cancer across the continental United States and data on incidence from selected areas of the country for evidence of an association between this disease and exposure to radioactive iodine (131 I) from nuclear tests in Nevada in the 1950s. Methods: Analyses involving 4602 thyroid cancer deaths (1957-1994) and 12 657 incident cases of thyroid cancer (1973-1994) were performed. Excess relative risks (ERRs) per Gray (Gy) of radiation were estimated by relating age-, calendar year-, sex-, and county-specific rates to estimates of dose to the thyroid that take age at exposure into account. Results: Analyses of cumulative dose yielded negative ERRs that were not statistically significant. An association was suggested for dose received by children under 1 year of age for both mortality data (ERR per Gy = 10.6; 95% confidence interval [CI] =-1.1 to 29) and incidence data (ERR per Gy = 2.4; 95% CI =-0.5 to 5.6); no association was found for dose received at older ages. For mortality data, but not incidence data, there was an elevated ERR in the 1950-1959 birth cohort of 12.0 (95% CI = 2.8 to 31) per Gy. Conclusions: Risk of thyroid cancer from exposure to 131 I from atmospheric nuclear tests did not increase with cumulative dose or dose received at ages 1-15 years, but associations were suggested for individuals exposed under 1 year of age and for those in the 1950-1959 birth cohort. The absence of increased risk from dose received at ages 1-15 years is not consistent with studies of children exposed to external radiation sources. This inconsistency may result from the limitations and biases inherent in ecologic studies, including the error introduced when studying a mobile population. These problems preclude making a quantitative estimate of risk due to exposure; however, given such limitations, it is perhaps remarkable that any evidence of the effects of 131 I emerges from this study. [