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Title: Thyroid neoplasia in Marshall Islanders exposed to nuclear fallout

Abstract

We studied the risk of thyroid neoplasia in Marshall Islanders exposed to radioiodines in nuclear fallout from the 1954 BRAVO thermonuclear test. We screened 7266 Marshall Islanders for thyroid nodules; the islanders were from 14 atolls, including several southern atolls, which were the source of the best available unexposed comparison group. Using a retrospective cohort design, we determined the prevalence of thyroid nodularity in a subgroup of 2273 persons who were alive in 1954 and who therefore were potentially exposed to fallout from the BRAVO test. For those 12 atolls previously thought to be unexposed to fallout, the prevalence of thyroid nodules ranged from 0.9% to 10.6%. Using the distance of each atoll from the test site as a proxy for the radiation dose to the thyroid gland, a weighted linear regression showed an inverse linear relationship between distance and the age-adjusted prevalence of thyroid nodules. Distance was the strongest single predictor in logistic regression analysis. A new absolute risk estimate was calculated to be 1100 excess cases/Gy/y/1 X 10(6) persons (11.0 excess cases/rad/y/1 million persons), 33% higher than previous estimates. We conclude that an excess of thyroid nodules was not limited only to the two northern atolls but extendedmore » throughout the northern atolls; this suggests a linear dose-response relationship.« less

Authors:
; ;
Publication Date:
Research Org.:
Univ. of Washington, Seattle
OSTI Identifier:
6367461
Resource Type:
Journal Article
Resource Relation:
Journal Name: JAMA, J. Am. Med. Assoc.; (United States); Journal Volume: 258:5
Country of Publication:
United States
Language:
English
Subject:
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.; NEOPLASMS; RADIOINDUCTION; THYROID; RADIATION DOSES; DELAYED RADIATION EFFECTS; DOSE-RESPONSE RELATIONSHIPS; FALLOUT; GEOGRAPHICAL VARIATIONS; MARSHALL ISLANDS; THYROIDECTOMY; BIOLOGICAL EFFECTS; BIOLOGICAL RADIATION EFFECTS; BODY; DISEASES; DOSES; ENDOCRINE GLANDS; GLANDS; ISLANDS; MEDICINE; MICRONESIA; OCEANIA; ORGANS; RADIATION EFFECTS; SURGERY; VARIATIONS; 560161* - Radionuclide Effects, Kinetics, & Toxicology- Man

Citation Formats

Hamilton, T.E., van Belle, G., and LoGerfo, J.P. Thyroid neoplasia in Marshall Islanders exposed to nuclear fallout. United States: N. p., 1987. Web. doi:10.1001/jama.258.5.629.
Hamilton, T.E., van Belle, G., & LoGerfo, J.P. Thyroid neoplasia in Marshall Islanders exposed to nuclear fallout. United States. doi:10.1001/jama.258.5.629.
Hamilton, T.E., van Belle, G., and LoGerfo, J.P. Fri . "Thyroid neoplasia in Marshall Islanders exposed to nuclear fallout". United States. doi:10.1001/jama.258.5.629.
@article{osti_6367461,
title = {Thyroid neoplasia in Marshall Islanders exposed to nuclear fallout},
author = {Hamilton, T.E. and van Belle, G. and LoGerfo, J.P.},
abstractNote = {We studied the risk of thyroid neoplasia in Marshall Islanders exposed to radioiodines in nuclear fallout from the 1954 BRAVO thermonuclear test. We screened 7266 Marshall Islanders for thyroid nodules; the islanders were from 14 atolls, including several southern atolls, which were the source of the best available unexposed comparison group. Using a retrospective cohort design, we determined the prevalence of thyroid nodularity in a subgroup of 2273 persons who were alive in 1954 and who therefore were potentially exposed to fallout from the BRAVO test. For those 12 atolls previously thought to be unexposed to fallout, the prevalence of thyroid nodules ranged from 0.9% to 10.6%. Using the distance of each atoll from the test site as a proxy for the radiation dose to the thyroid gland, a weighted linear regression showed an inverse linear relationship between distance and the age-adjusted prevalence of thyroid nodules. Distance was the strongest single predictor in logistic regression analysis. A new absolute risk estimate was calculated to be 1100 excess cases/Gy/y/1 X 10(6) persons (11.0 excess cases/rad/y/1 million persons), 33% higher than previous estimates. We conclude that an excess of thyroid nodules was not limited only to the two northern atolls but extended throughout the northern atolls; this suggests a linear dose-response relationship.},
doi = {10.1001/jama.258.5.629},
journal = {JAMA, J. Am. Med. Assoc.; (United States)},
number = ,
volume = 258:5,
place = {United States},
year = {Fri Aug 07 00:00:00 EDT 1987},
month = {Fri Aug 07 00:00:00 EDT 1987}
}
  • A medical survey of the Marshallese people in March 1959, five years after exposure to fallout radiation, showed that the people had recovered from the acute effects of their radiation exposure and appeared to be generally in good health. No illnesses or diseases were found that could be directly associated with acute radiation effects. One case of cancer and three deaths had occurred, but with no direct relation to radiation effects. Fertility did not appear to be affected. The incidence of miscarriages and stillbirths appeared to be somewhat higher than in the unexposed Marshallese, but a deficiency of vital statisticsmore » precluded definite conclusions as to whether or not this is a radiation effect. Suggestive evidence of slight lag in growth and development of exposed children noted previously was re-evaluated on the basis of better age data obtained during the latest survey. Blood platelet levels were within the normal range but somewhat below that for the unexposed population. Only 11 cases showed residual changes in the skin from beta burns. None ~howed any evidence of cancerous change. Possible late effects of radiation such as shortening of life span, premature aging, increased incidence of leukemia and malignancies, increased incidence of degenerative diseases, opacities of the lens of the eyes, and genetic changes were not detected. The original body burdens of internally absorbed fission products appeared to be too low to have produced any acute or long-term effects. The return of the people to the slightly contaminated island of Rongelap resulted in some increase in body burdens of Cs/sup 137/, Zn/sup 65/, and Sr/sup 90/. However, the levels were far below the accepted maximum permissible limits, and it is not believed any detrimental effects will result. (auth)« less
  • Between 1944 and 1956, approximately 19.6 PBq (530,000 Ci) of {sup 131}I were released to the atmosphere during Pu reprocessing for nuclear weapons at the Hanford nuclear facility in southeastern Washington state. For these years, we summarized historical records of quarterly 131I atmospheric releases and vegetation concentrations measured in nearby communities. We used these data and other reported environmental measurements to make preliminary estimates of maximum doses to the thyroid for the general public. We also computed the statistical power for an epidemiologic study of thyroid neoplasia in birth cohorts of children born in two counties near Hanford during themore » years of highest exposure. These estimates suggest that an epidemiologic study would be feasible if the actual average radiation doses in the exposed population were no less than one-tenth the preliminary maximum doses. Our analyses also suggest that it may be more appropriate to stratify the exposed population by cumulative dose in order to examine the relation between radiation exposure and thyroid neoplasia.« less