Fifty years of plutonium exposure to the Manhattan Project plutonium workers: an update.

Twenty-six white male workers who did the original plutonium research and development work at Los Alamos have been examined periodically over the past 50 y to identify possible health effects from internal plutonium depositions. Their effective doses range from 0.1 to 7.

Cumulative genetic damage in hematopoietic stem cells in a patient with a 40-year exposure to alpha particles emitted by thorium dioxide.

Thorotrast, a colloidal suspension of the long-lived radionuclide, thorium-232, was widely used as a radiographic contrast medium for several decades. Due to the poor excretion of the sol, however, Thorotrast would deposit in the liver, bone marrow and other tissue, and patients would receive alpha-particle irradiation for life. To gauge the cumulative genetic damage to hematopoietic stem cells due to chronic exposure to alpha particles, we conducted a multi-end-point evaluation in a 72-year-old man who had been administered a 32-ml bolus of Thorotrast during cerebral angiography performed over 40 years ago in 1950.

Mortality through 1990 among white male workers at the Los Alamos National Laboratory: considering exposures to plutonium and external ionizing radiation.

A cohort mortality study was conducted of 15,727 white men employed by the Los Alamos National Laboratory, a nuclear research and development facility. Some of the workers at this facility have been exposed to various forms of ionizing radiation and other potentially hazardous materials. These analyses focused on whole-body ionizing radiation exposures and internal depositions of plutonium.

Health considerations for workers exposed to plutonium.

It is interesting to observe that today the discussions, public concerns, and legal battles over health risks presented by Pu are not only vigorous but also accelerating. Our knowledge of the biochemistry, pathophysiology, dosimetry, and radiobiology of Pu has increased enormously during the intervening 45+ years since the first experiments. For the first time in the history of science and industry, extensive epidemiologic studies are being conducted on the majority of all people in this country who have worked with a material since its introduction and before anyone has had any known acute or chronic illness from exposure to it.

A 42-y medical follow-up of Manhattan Project plutonium workers.

Twenty-six white male subjects, who worked with plutonium (239Pu) during World War II at Los Alamos, have been given medical examinations periodically over a period of 42 y to identify potential health effects. Inhalation was the primary mode of Pu exposures. The latest examinations, including urine bioassay and in-vivo measurements for radioactivity, were performed in late 1986 and 1987.

Mortality among a cohort of workers monitored for 210Po exposure: 1944-1972.

This study represents the largest epidemiologic investigation of humans exposed to the radionuclide 210Po. In a cohort of 4402 white males employed by the Mound Facility, during the period when Po operations were conducted (1944-1972), no excess mortality was observed. Among workers initially hired during World War II, mortality was elevated, especially for deaths from all cancers, cancers of the lung, and cancers of the rectum.

U.S. Transuranium Registry report on the 239Pu distribution in a human body.

The distribution of 239Pu in a human whole body is reported. The body contained 246 Bq of 239Pu of which 130 Bq (52.8%) was found in the lungs and associated lymph nodes.

Methods for analyzing combined data from studies of workers exposed to low doses of radiation.

Epidemiologic studies of workers exposed occupationally to protracted low doses of radiation provide a direct assessment of health effects resulting from such exposure and thus supplement information provided by studies of populations exposed at high doses of radiation and high dose rates. Analyses based on combined data from several studies can be expected to provide a more thorough assessment of low dose occupational studies and more precise risk estimates than can be obtained from any single study. Statistical methods for conducting such combined analyses are discussed, and different approaches, such as basing analyses on various levels of aggregation of exposure data, are compared and evaluated.

Analyses of combined mortality data on workers at the Hanford Site, Oak Ridge National Laboratory, and Rocky Flats Nuclear Weapons Plant.

An important objective of studies of workers exposed occupationally to chronic low doses of ionizing radiation is to provide a direct assessment of health risks resulting from this exposure. This objective is most effectively accomplished by conducting combined analyses that allow evaluation of the totality of evidence from all study populations. In this paper, combined analyses of mortality in workers at the Hanford Site, Oak Ridge National Laboratory, and Rocky Flats Nuclear Weapons Plant are presented.

Mortality among plutonium and other radiation workers at a plutonium weapons facility.

Mortality among 5,413 white males who were employed for at least two years at a plutonium weapons facility was investigated to measure risks from exposures to low levels of plutonium and external radiation. When compared with US death rates, fewer deaths than expected were found for all causes of death, all cancers, and lung cancer. No bone cancer was observed.

A 37-year medical follow-up of Manhattan Project Pu workers.

Twenty-six male subjects, who worked with Pu during World War II under extraordinarily crude conditions, have been given medical examinations periodically over the past 37 y to identify potential health effects. Inhalation was the primary mode of the Pu exposures. Current estimates of the systemic Pu depositions in these individuals range from 2 to 95 nCi with a mean of 26 nCi.

Brain tumors at a nuclear facility.

In response to an observed excess risk of brain tumor deaths among workers at the Rocky Flats Nuclear Facility (Colorado), a case-control study of all (n = 16) primary brain tumor deaths occurring among white males employed during 1952 through 1977 was conducted to investigate their relationship with occupational radiation/nonradiation exposures. For each case, four controls were individually matched on year of birth and period of employment. Although limited by a small number of cases, our study showed no statistically significant association between brain tumor death and exposure to internally deposited plutonium, external radiation, or other occupational risk factors.

A melanoma case-control study at the Los Alamos National Laboratory.

We conducted a melanoma case-control study at the Los Alamos National Laboratory to investigate whether related occupational exposures or personal characteristics of employees could be identified. This study was prompted by a recent report from the Lawrence Livermore National Laboratory that melanoma was much more frequent than expected among employees and that persons suffering from melanoma more often worked as chemists. Our investigation did not uncover an association with plutonium body burden, cumulative external radiation exposure, or employment as a chemist or a physicist.

An update of epidemiologic studies of plutonium workers.

Retrospective and prospective epidemiologic studies are being conducted as part of a national survey of plutonium workers at four Department of Energy facilities (Los Alamos, NM; Rocky Flats, CO; Mound Laboratory, OH; and Savannah River, SC). A preliminary analysis of mortality was done for all white males who have worked at the Rocky Flats Plant during the period 1952-79. The 452 observed deaths were significantly fewer than the 831 expected for all causes.

Malignant melanoma incidence at the Los Alamos National Laboratory.

In an analysis of melanoma incidence for 1969 to 1978 among 11 308 workers at the Los Alamos National Laboratory in New Mexico 6 cases were detected in the total cohort, in which 5.69 cases would be expected (standardised incidence ratio [SIR] = 105; 90% confidence interval [CI] = 51,198) on the basis of incidence rates for the State of New Mexico, specific for age, sex, and ethnic origin. Among the White non-Hispanic men, 3 cases were detected, whereas 4.

Evaluation of Social Security follow-up of some southwestern populations.

A study of the completeness of death ascertainment through the Social Security Administration (SSA) was undertaken. Groups of subjects of known vital status were submitted by the Los Alamos National Laboratory to the SSA for a mortality record search. Correctly ascertained deaths ranged from 77% to 90% among males and from 53% to 76% among females.