Selection, follow-up, and analysis in the Atomic Bomb Casualty Commission Study.

More is known about ionizing radiation as a cause of human cancer than about any other carcinogen. Most of this knowledge is derived from the studies conducted by the Atomic Bomb Casualty Commission and Radiation Effects Research Foundation on about 100,000 Japanese survivors of the atomic bombing in 1945. The importance of these studies is based on the large size of the exposed population and the fact that individual estimates of radiation dose were possible. These factors and the combined excellence of the centralized vital statistics reporting and population registration systems in Japan have made feasible the continuing longitudinal studies of cancer mortality by site in relation to radiation dose over a span of more than 30 years. Excellent voluntary cooperation by the survivors has enabled the continuation of a biennial physical examination program which has made possible the acquisition of blood for studies of radiation-induced chromosomal aberrations and mutations at the level of specific genes. Similarly, with the cooperation of local universities, hospitals, and physicians, tumor and tissue registries necessary for the study of cancer incidence have been developed. An autopsy pathology program has enabled study of the accuracy of cause of death certification.

Mortality among workers at a nuclear power plant in the United States.

A second follow-up of 9,000 workers at the Calvert Cliffs Nuclear Power Plant (MD, USA) identified 346 deaths in the years 1969-88, 101 of which were attributed to malignant neoplasms. The original study had the primary purpose of assessing the feasibility of studies of workers based upon individual plant and Nuclear Regulatory Commission records. The average, cumulative, occupational dose through 1984 was low, only 21 mSv, but ranged up to 470 mSv, with 12 percent of the workers receiving more than 50 mSv. Mortality from most causes of death was low and there was a deficit of deaths from diseases of the circulatory system. Ionizing radiation exposures were not related to the probability of death from neoplasms generally or from any specific form of cancer. There were only two deaths from leukemia, whereas four were expected at population death rates. Larger numbers of workers, followed for longer periods of time, are needed to determine the mortality risk to workers in the nuclear power industry. The difficulties in obtaining dose information for transient workers were so great, and so time consuming, as to make questionable the practicability of studying the workers at a large number of power plants in this way.

Army rank and subsequent mortality by cause: 23-year follow-up.

Mortality among veterans has been studied in relation to military rank at separation in a series of 85,491 men discharged from the US Army in 1946 and traced through 1969. It was found that although the mortality of privates was very close to expectation based on population rates, non-commissioned officers had a 23% advantage and commissioned officers about a 40% advantage. The relative advantage of the veterans who had higher rank held not only for deaths from all causes but also for most of the specific causes examined and there was only a small tendency for the differences to diminish with the passage of time during the 23-year period of follow-up.

Army technologists: 29-year follow up for cause of death.

A previous 18-year follow-up study revealed no significant excess of cancer among men who served in the Army during World War II as radiological technologists (n = 6,560) as compared with men who served as medical, laboratory, or pharmacy technologists (n = 6,826). Extension of the follow up by 11 years (1946-1974) revealed that 145 former radiological technologists had died of cancer, as compared with 158 controls. No statistically significant differences were found between these groups for individual sites of cancer or for deaths from other causes.

Agreement between death certificate and autopsy diagnoses among atomic bomb survivors.

Based on the Atomic Bomb Casualty Commission/Radiation Effects Research Foundation series of over 5,000 autopsies, we examined death certificate accuracy for 12 disease categories and assessed the effect of potential modifying factors on agreement and accuracy. The overall percentage agreement between death certificate and autopsy diagnoses was only 52.5%. Although neoplasms had the highest detection rate, almost 25% of cancers diagnosed at autopsy were nevertheless missed on death certificates. Confirmation and detection rates were above 70% for neoplasms and external causes of death only. Confirmation rates were between 50 and 70% for infectious diseases and heart and other vascular diseases. Detection rates reached a similar level for infectious, cerebrovascular, and digestive diseases. Specificity rates were above 90% for all except the cerebrovascular disease category. Overall agreement decreased with increasing age at death and was worse for deaths occurring outside of hospital. There was some suggestion that agreement improved over time, but no indication that radiation dose, sex, city of residence, or inclusion in a biennial clinical examination program influenced agreement. Since the inaccuracy of death certificate diagnoses can have major implications for health research and planning, it is important to be aware that their accuracy is low and that it can vary widely depending on cause, age and place of death.

Cancer in populations living near nuclear facilities. A survey of mortality nationwide and incidence in two states.

Reports from the United Kingdom have described increases in leukemia and lymphoma among young persons living near certain nuclear installations. Because of concerns raised by these reports, a mortality survey was conducted in populations living near nuclear facilities in the United States. All facilities began service before 1982. Over 900,000 cancer deaths occurred from 1950 through 1984 in 107 counties with or near nuclear installations. Each study county was matched for comparison to three "control counties" in the same region. There were 1.8 million cancer deaths in the 292 control counties during the 35 years studied. Deaths due to leukemia or other cancers were not more frequent in the study counties than in the control counties. For childhood leukemia mortality, the relative risk comparing the study counties with their controls before plant start-up was 1.08, while after start-up it was 1.03. For leukemia mortality at all ages, the relative risks were 1.02 before start-up and 0.98 after. For counties in two states, cancer incidence data were also available. For one facility, the standardized registration ratio for childhood leukemia was increased significantly after start-up. However, the increase also antedated the operation of this facility. The study is limited by the correlational approach and the large size of the geographic areas (counties) used. It does not prove the absence of any effect. If, however, any excess cancer risk was present in US counties with nuclear facilities, it was too small to be detected with the methods employed.

Effects upon health of occupational exposure to microwave radiation (radar).

The effects of occupational experience with microwave radiation (radar) on the health of US enlisted Naval personnel were studied in cohorts of approximately 20,000 men with maximum opportunity for exposure (electronic equipment repair) and 208000 with minimum potential for exposure (equipment operation) who served during the Korean War period. Potential exposure was assessed in terms of occupational duties, length of time in occupation and power of equipment at the time of exposure. Actual exposure to members of each cohort could not be established. Mortality by cause of death, hospitalization during military service, later hospitalization in Veterans Administration (VA) facilities, and VA disability compensation were the health indexes studied, largely through the use of automated record systems. No adverse effects were detected in these indexes that could be attributed to potential microwave radiation exposures during the period 1950-1954. Functional and behavioral changes and ill-defined conditions, such as have been reported as microwave effects, could not be investigated in this study but subgroups of the living study population can be identified for expanded follow-up.

Effects of relaxation training on glucose tolerance and diabetic control in type II diabetes.

The present study examined the effects of progressive relaxation training and EMG biofeedback on acute glucose disposal in diabetic subjects, as measured by glucose tolerance and three other measures of diabetic metabolic control. Twenty subjects with non-insulin-using Type II diabetes took part in progressive relaxation training and EMG biofeedback in a pre-post treatment versus wait-list experimental design. Treatment effects were assessed on glucose tolerance along with three measures of diabetic control: fasting blood glucose, two-hour postprandial blood glucose, and fructosamine. Stress reduction and relaxation was assessed with two physiological measures and two subjective questionnaires. The training program produced significant reductions in stress, as measured by State Anxiety, and significant changes in physiological measures of muscle activity and skin conductance compared to the control condition. However, no changes were found in glucose tolerance (while practicing relaxation) nor in any of the three measures of general diabetic metabolic control. The major implication of this study is that relaxation training does not appear to directly improve diabetic control in mildly stressed non-insulin-using Type II diabetic patients.