Biomedical subjects

G L Voelz

Publications and source records attributed to G L Voelz.

At least 19 recordsLinked to original sources

PubMed1991

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. Of the remaining 116 Bq (47.2%) that constituted the systemic deposition, 51.2 Bq (44%) were in the skeleton, 48.6 Bq (42%) in the liver, and the remainder (14%) in the rest of the body exclusive of the lungs and associated lymph nodes. An unexpectedly high concentration was observed in the pituitary. The systemic distribution of Pu in this case, when combined with the exposure history, is suggestive of an initial partitioning ratio of 239Pu between skeleton and liver of less than unity, and a tentative initial distribution from the transfer compartment of 25% to the skeleton, 50% to the liver, and 25% to the rest of the body and early excretion is proposed for this case. Older biokinetic models, when used with the available urinalysis data for this case, typically overestimated the deposition when compared with the tissue analysis results, but more recent models provided estimates in close agreement with the autopsy results.

Actinoid Series Elements↗

PubMed1991

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. These adverse health events do not appear related to exposure to 210Po. Among workers monitored for 210Po, mortality was significantly less than expected, although more lung cancers were observed than expected. No significant dose-response trends were identified for all causes combined, all cancers combined, or for cause-specific cancers among the Po-monitored subcohort. Continued follow-up of this cohort is planned.

Cohort Studies↗

PubMed1991

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. The average age of the 22 living subjects in 1986 was 66 y. The diseases and physical changes noted in these persons are characteristic of a male population in their 60s. Estimates of individual Pu depositions, including lung burdens, as of 1987 or at time of death range from 52 to 3180 Bq (1.4 to 86 nCi) with a median value of 500 Bq (13.5 nCi). Four persons from the original group had died as of 1987. The causes of death were lung cancer, myocardial infarction, accidental injury, and respiratory failure due to pneumonia/congestive heart failure. Expected deaths based on U.S. death rates of white males, adjusted for age and calendar year, are 9.2 based on U.S. rates (standardized mortality ratio = 0.41). Subsequent to 1987, three additional deaths occurred from atherosclerotic heart disease, lung cancer, and osteogenic sarcoma. The bone sarcoma case is discussed in terms of Pu exposure, the natural incidence of this disease, anatomical location of the tumor, and bone tumors observed in Pu-exposed dogs. Plutonium deposition in this man is estimated to have been below current radiation protection guidelines.

Aged↗

PubMed1990

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. Emphasis is given to methods for obtaining risk estimates and confidence limits that can be appropriately compared with estimates that form the basis for current radiation protection standards; these estimates have been obtained through extrapolation from high dose data. Methods are illustrated using combined data on workers at three US Department of Energy facilities: the Hanford Site, Richland, Washington; the Oak Ridge National Laboratory, Oak Ridge, Tennessee; and the Rocky Flats Nuclear Weapons Plant, Denver, Colorado.

Colorado↗

PubMed1989

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. These combined analyses provide no evidence of a correlation between radiation exposure and mortality from all cancer or from leukemia. Of 11 other specific types of cancer analyzed, multiple myeloma was the only cancer found to exhibit a statistically significant correlation with radiation exposure. Estimates of the excess risk of all cancer and of leukemia, based on the combined data, were negative. Upper confidence limits based on the combined data were lower than for any single population, and were similar to estimates obtained from recent analyses of A-bomb survivor data. These results strengthen support for the conclusion that estimates obtained through extrapolation from high-dose data do not seriously underestimate risks of low-dose exposure, but leave open the possibility that extrapolation may overestimate risks.

Adult↗

PubMed1987

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. An excess of brain tumors was found for the cohort in general. Elevated rate ratios for all causes of death and all lymphopoietic neoplasms were found when employees with plutonium body burdens greater than or equal to 2 nCi were compared with those with body burdens less than 2 nCi, while accounting for age, calendar period, and induction time. Increased rate ratios were also found for esophageal, stomach, colon, and prostate cancers, and for lymphosarcomas and reticulum cell sarcomas. No elevated rate ratios were noted for bone and liver cancers. When employees with cumulative exposures greater than or equal to 1 rem were compared with those with exposures less than 1 rem, elevated rate ratios were found for myeloid leukemia, lymphosarcoma and reticulum cell sarcoma, liver neoplasms, and unspecified brain tumors. No overall dose-response relationships were found for plutonium or external radiation exposures. Standardized rate ratios increased, however, as plutonium body burden levels increased for all causes, all cancers, and digestive cancers at five years induction time. Standardized rate ratios also increased as external radiation exposure categories increased for all lymphopoietic cancers and unspecified brain tumors for a two-year induction period. With the exception of analyses of combined categories of death, and perhaps of lung cancer, confidence limits were wide, indicating limited precision. Nevertheless, these findings suggest that increased risks for several types of cancers cannot be ruled out at this time for individuals with plutonium body burdens of greater than or equal to 2 nCi. Plutonium-burdened individuals should continue to be studied in future years.

Air Pollutants, Radioactive↗

PubMed1985

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. Seven individuals have depositions of 40 nCi or more, often considered the lifetime maximum permissible body burden for workers. Two individuals have died compared to 6.6 expected deaths based on U.S. adjusted rates for white males. The causes of death were myocardial infarction and accidental trauma. Examinations completed in 1981-82 revealed no cases of cancer in the group except for a history of skin cancers in three individuals. The diseases and physical changes noted in these individuals are characteristic of a male population in their upper 50s or 60s. This study yields no evidence suggesting that adverse health effects have resulted from the 37 y of exposure to internally deposited Pu.

Aged↗

PubMed1984

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.

Adult↗

PubMed1983

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. The 107 deaths due to all malignant neoplasms were also significantly fewer than the 167 expected from these diseases. Expected deaths were derived from age and calendar-specific death rates for U.S. white males. Deaths reported for benign and unspecified neoplasms numbered eight versus an expected two, a significant elevation. These tumors, all intracranial, are the subject of a case-control study to be reported later. Subdividing the cohort on the basis of plutonium exposures and external radiation exposures results in similar overall findings. The benign and unspecified neoplasms, however, were not significantly high in the plutonium-exposed group.

Adult↗

PubMed1983

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. The major finding was that cases were more educated than controls. Melanoma risk was 2.11 among college-educated employees and increased to 3.17 among those with graduate degrees (Mantel-extension linear trend probability = 0.038). This finding is consistent with the often reported increased melanoma incidence among persons of higher social class. It points to personal characteristics, particular to persons of higher educational attainment, as risk factors for melanoma at the Los Alamos National Laboratory.

Adult↗

PubMed1982

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 4.4 would be expected. The associated SIR of 68 (90% CI = 23, 163) does not suggest excess melanoma incidence in this subcohort. A direct comparison with Statewide incidence rates gave similar results. These results do not agree with the threefold excess of malignant melanoma incidence found among White male employees at the Lawrence Livermore National Laboratory.

Adult↗

PubMed1982

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. A duplicate record search one year later raised correct ascertainment to 88% to 94% of male deaths and to 73% to 87% of female deaths. Death ascertainment appeared to be independent of ethnicity (Anglo and Hispanic), cause of death, location of death, and year of death. Age at time of death was strongly related to death ascertainment. Individuals 65 years of age and over were identified much more accurately than persons less than 65 years of age. Lack of incentive to report deaths of persons under retirement age is believed to be responsible. The age of an industrial facility and of the work force may have a major influence on the adequacy of mortality ascertainment through social security.

Age Factors↗

PubMed1982