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This paper attempts to provide an integrative, multifaceted treatment approach for the surviving POW and his family. The model takes into account the individual, family, interpersonal, and community effects of captivity from the time of captivity until 1 year later. Ramifications of this model are discussed.

Over exposure to cadmium may produce numerous adverse health effects, including changes in the nasal mucosa. Cadmium levels were measured in blood and urine samples taken from 106 workers who were exposed to high levels of cadmium and nickel in a cadmium nickel battery plant. Pathological results were observed in 46% and 51% of the blood and urine samples respectively. A positive association was found between clinical nasal complaints and pathological levels of cadmium in blood (P = 0.006) and urine (P = 0.045) samples. All the workers underwent sinus X-rays and 63% of them were abnormal. No correlation was found between pathological sinus X-rays and pathological cadmium level in blood and urine samples. A positive correlation was found between clinical nasal complaints and abnormal sinus X-rays. The prevalence of sinus X-ray abnormalities in an asymptomatic general population is 33% as compared to 63% in our study. This difference is highly significant statistically (P < 0.0001). Our result shows a possible harmful effect of cadmium on the paranasal sinuses.

This study investigated the importance of personal determinants such as self-efficacy, beliefs about the contribution of exercise, health locus of control, and dispositional optimism for leisure-time exercise in a working population. The main predictors of such exercise were beliefs and self-efficacy with the generalization of the latter to eat correctly. Beliefs and efficacy expectations were highly correlated. Neither health locus of control nor dispositional optimism was related to leisure-time exercise; however, optimism was related to the positive belief that exercise contributes to health. Ramifications of the findings were carefully described.

Malignant mesothelioma is a lethal disease. It is rare in the general population; however, workers exposed to asbestos suffer significant burdens of the neoplasm. The survival time of 457 consecutive fatal cases of pleural and peritoneal mesothelioma that occurred among 17,800 asbestos insulation workers observed prospectively from 1 January 1967 to 1 January 1987 was studied. Mean survival time from initial presentation of the disease to death was 11.4 months for the pleural mesothelioma patients compared with 7.4 months for the peritoneal group. This difference was statistically significant. Mean survival time from diagnosis to death was shorter for both groups of patients: 8.4 months for pleural mesothelioma v 5.8 months for the peritoneal cases. In conclusion, survival time in mesothelioma patients is short; most die within a year from the onset of the initial symptoms. No effective therapy is yet available.

We used measurements of heat stress in the cockpit of Bell 206 and 212 helicopters manned by a crew of two to predict changes in the skin temperatures of 50 pilots over a 1-h ground standby period. Cockpit wet bulb globe temperatures increased from 28.1 +/- 5.6 degrees C to 32.9 +/- 3.9 degrees C over the 1-h ground standby period. Skin temperatures increased from 34.7 +/- 1.1 to 35.4 +/- 1.1 degrees C, while heart rate increased from 79.4 +/- 9.6 to 82.6 +/- 9.8 bpm. Cockpit wet bulb temperatures explained 26.9% of the variance of the increase in skin temperature (P = 0.0002). Wet bulb globe temperatures, discomfort index and dry bulb temperatures did not improve the predictive value of wet bulb temperatures alone. Relative humidity was not significantly associated with the increase in skin temperature. We conclude that wet bulb temperatures predict changes in skin temperature as well as other heat stress indices. Furthermore, despite high cockpit temperatures, pilots experienced only minimal strain during the 1-h ground standby period. Extrapolation of our results to the effects on body temperature of higher degrees of heat stress and physical activity is unwarranted and deserves further study.

Occupational cancer is a result of exposure to carcinogens in the workplace. The critical interaction during the initiation stage of the carcinogenesis process occurs between the ultimate form of a carcinogen and the DNA, resulting in the formation of a DNA adduct or several types of gross structural alterations. Several methods have been developed by which carcinogens can be detected. These methods can be utilized for ambient monitoring of exposure and health surveillance. "Molecular epidemiology" is the combination of epidemiologic and laboratory studies, i.e., monitoring exposure by measuring the DNA adduct. Early detection of occupational cancer is difficult, due largely to the latent period which can be up to 20 years or more. For this reason it is important to develop and improve techniques for early detection of premalignant changes. Israel has numerous workers who are exposed to carcinogens, but has no special legislation concerning the use of carcinogenic substances in the workplace. However, an interministerial committee has published, and is continuing to work on, exposure and safety regulations. Medical surveillance and prevention as well as legislation are necessary to reduce morbidity and mortality from occupational cancer.

Ethylene oxide is a colorless gas that can cause neoplastic disease (leukemia, stomach cancer) in animals and humans. Its mutagenic potential is expressed by chromosome aberrations and sister chromatid exchange, as has been shown in numerous studies of groups exposed to ethylene oxide. The results of our pilot study on the effects of exposure to high levels of ethylene oxide show chromosome breakage in exposed individuals at twice the frequency of the normal population. Although these are preliminary findings, they justify urgent, specific protection from further exposure.

Tobacco smoke contains a wide range of toxic vapors and particles which when inhaled are injurious both to the smoker himself (active smoking) and to those around him (passive smoking). It is extremely difficult to define precisely the harmful effects of passive smoking on the individual's health because of problems in quantifying the extent of exposure. A number of epidemiological studies indicate that exposure to passive smoking in public places is circumstantially, but marginally, linked to cardiovascular morbidity and mortality, as well as to pulmonary morbidity. both benign and malignant. Many clinical conditions are further aggravated by exposure to a combination of tobacco smoke and other industrial materials, including cadmium, and radon daughters. Passive smoking during pregnancy constitutes a health hazard for both mother and fetus. Exposure to passive smoking during childhood may predispose to benign and malignant pulmonary morbidity in adulthood. For many the workplace is the main site of exposure. In a pilot study during the past year on 1197 white and blue-collar workers, we found that the proportion of nonsmokers exposed to tobacco smoke at work is very high, almost 80%, and that workers are bothered by it. 2/3 are aware of the serious adverse health effects of tobacco smoke. 98% of the passive smokers and 75% of the active smokers considered legislation to limit smoking in public places justified.

Progressive systemic sclerosis (PSS; scleroderma) is a multisystem disease characterized by inflammation, fibrosis and degeneration of the integument, with similar changes and vascular lesions in the heart, lungs, kidneys, gastrointestinal tract and synovia. Its etiology is not clear. Several occupational exposures have been implicated as potential causes of PSS and scleroderma-like diseases. Among them are vinyl chloride monomer, silica dust, epoxy resin, and benzene and other solvents, aromatic and aliphatic, specifically chlorinated (trichloroethylene, perchloroethylene and trichloromethane). We present a patient whose illness was diagnosed as occupationally induced PSS. During 13 years of work renovating carburetors he was heavily exposed to trichloromethane. To the best of our knowledge this is the first reported case of PSS due to exposure to organic solvents in Israel; very few cases have been reported from abroad.

One hundred fifty-two workers who had been exposed to different levels of cadmium (Cd) absorption (blood Cd mean 16.34 micrograms/L, median 11.0 micrograms/L) in a factory making nickel-cadmium batteries were studied. A physical evaluation, as well as blood and urine cadmium and N-acetyl-beta-D-glucosaminidase (NAG), and other routine laboratory tests were performed in order to assess the relationship between different levels of exposure to occupational cadmium and potential cadmium-induced renal damage and other adverse health effects. We found significant correlation between levels of cadmium exposure and a selected group of symptoms and signs. The best predictor of this group of symptoms and signs was an indicator called internal dose index (Cd x exposure time). This indicator appears as the strongest, even after control by confounding factors, such as age and smoking. It is concluded that this index can be used for biological monitoring.

Tobacco smoke contains a wide range of toxic vapors and particles that when inhaled are injurious to the smoker himself (active smoking) and to those around him (passive smoking). It is extremely difficult to define precisely the harmful effects of passive smoking on the individual's health because of the problems involved in quantifying the extent of exposure. A number of epidemiological studies indicate that exposure to passive smoking in public places is circumstantially but marginally linked to cardiovascular morbidity and mortality, as well as to benign and malignant pulmonary morbidity. There is an increased risk of cardiovascular and lung diseases among people living with spouses who smoke due to the exposure to tobacco smoke in the home. Passive smoking during pregnancy constitutes a health hazard for mother and fetus alike. Exposure to passive smoking during childhood may predispose the individual to benign and malignant pulmonary morbidity in both childhood and adulthood. For many people the worksite comprises the main exposure source. Many clinical conditions are further aggravated by exposure to a combination of tobacco smoke and industrial chemicals, mineral dust, or other carcinogens (asbestos, cadmium, radon daughters). Tobacco smoke exposure and the resultant morbidity can be reduced by regulations and legislation prohibiting smoking in public places and worksites.

This paper describes the personal determinants in health promoting behavior, and, in particular, life style changes. A review is made of internal factors, including personality factors, health beliefs, and health attitudes. Environment factors are also taken into account. Suggestions for future research are proposed.

This study investigated the amount of psychological distress reported by 182 soldiers in the Israeli military and compared soldiers' self-ratings of distress with ratings by military physicians of observed distress. Comparisons indicated a low detection rate by physicians with only 13% of self-reported cases of emotional distress identified. This and several related findings were taken to indicate shortcomings in medical care. Possible remedies include additional psychiatric training for military physicians, less frequent rotation of physicians to allow for more stable care, and the initiation of mental health education among soldiers.

Accuracy of diagnosis of malignant mesothelioma (pleural and peritoneal) was studied in a cohort of asbestos insulation workers in the United States and Canada. Initial clinical diagnosis, clinical diagnosis at death and death certificate diagnosis were compared with the diagnosis of malignant mesothelioma ascertained by full data review at the Division of Environmental and Occupational Medicine, Mount Sinai Medical Center, New York ('best evidence'). In both groups the death certificate diagnosis was somewhat less frequently accurate than clinical diagnosis at death. Knowledge of the patients' occupational history by the attending physician and its relation to accuracy of diagnosis of malignant mesothelioma is considered.

In this study, the amount of psychological distress reported by soldiers is investigated and measured over time. The soldiers--enlisted and career--were randomly chosen while visiting five different military primary care clinics (for ostensible somatic problems) and administered the General Health Questionnaire (Goldberg and Huxley, 1980). A third of the subjects were given the GHQ a year later. Fifty-two percent showed psychological stress: combat soldiers showed considerably less distress than technical/maintenance and administrative soldiers, and the psychological stress findings remained relatively stable over time. Possible explanations for these findings are discussed.

We attempted to determine the optimal cut-off value of blood pressure defining a hypertensive response to exercise testing in 90 asymptomatic Israeli candidates for flight training with casual resting blood pressure of 140/90 mm Hg or more, and 72 age-matched normotensive controls tested in the Israel Air Force Aeromedical Center. Exercise testing (Bruce protocol) was performed using a calibrated Quinton Treadmill and a Hewlett Packard 151711-A three-channel ECG recording system. Recordings were made at 3-min intervals. At 3 min of exercise 12/87 (14%) of the hypertensive subjects had a SBP of greater than or equal to 210, compared to only 1/71 (1%) of the control group (relative risk 14). At 12 min of exercise 27/51 (53%) of the hypertensives and 9/55 (16%) of the controls had similar elevations of SBP (relative risk 3.3). At 6 min of exercise 11/87 (13%) of hypertensives had SBP greater than or equal to 220, whereas none of the normal controls had SBPs elevated to that degree. We concluded that an increase in SBP to 210 mm Hg or more after 3 min or to 220 mm Hg after 6 min of exercise testing by the Bruce protocol best separates the hypertensive group from the control group. This occurs at the expense of sensitivity. Only appropriate longitudinal studies can compare the degree to which various definitions of the hypertensive response to exercise will predict future hypertension.

The effect of repeated doses of 30 mg pyridostigmine bromide every 8 h on flight skills in an A-4 simulator was tested in this crossover double-blind placebo-controlled study on 10 pilots experienced in actual and simulated A-4 flights. The pilots flew two test simulator flights 2 h after the fourth dose of pyridostigmine or placebo. The flight profile included navigation, rapid ascent, 360 degrees turns, and instrument landing. Each flight lasted approximately 20 min. Flight parameters measured included indicated air speed, true heading, barometric altitude, vertical velocity, and bank. The mean whole blood cholinesterase inhibition level was 29%. There was no decrement in performance under treatment with pyridostigmine in the percent of deviation time from the prescribed limits or in the average duration or magnitude of the deviation in each of the flight parameters. We conclude that pyridostigmine bromide in repeated doses of 30 mg every 8 h does not appear to influence pilot performance during short A-4 missions.

In order to evaluate the possible role of an endogenous rhythmic factor in Air Force flight accidents a retrospective study was carried out. The study included all Air Force (aircraft) flying accidents which have been attributed to pilot's error and which occurred, in peace time missions, over a period of 12 years (1968-1980). The frequency of hourly accidents was computed separately, for each year, for each month, for each day of the week, and for each calendar day. Identical computations were carried out for the frequency of hourly flights. When the hourly ratios of these two parameters were computed, by dividing the value of one parameter to the other at each hour, a rhythmic (rather than constant) diurnal pattern was obtained. The pattern was defined as the "Hourly Accident Coefficient (HAC)". The HAC values ranged from 1.58 to 0.68 (pooled data for all surveyed aircrafts) and from 4.12 to 0.74 (data for fighter planes). The pattern, which exhibited a diurnal rhythm, was independent of the frequency of flights and appeared to be related to the sleep-wake cycle of the pilots, especially to the time of waking from the night sleep. The results are used as a directive for a progressive study aimed at evaluating the practical implications of the presented observations.

Tricuspid valve prolapse is commonly associated with mitral valve prolapse or other heart abnormalities and is rarely found as an isolated finding. A patient with isolated tricuspid valve prolapse is described which was discovered on routine examination of an asymptomatic pilot.

The abnormal ECG T wave changes associated with mitral valve prolapse (MVP) were studied and quantitated in a group of 36 asymptomatic individuals with MVP and compared with a 27-member control group. The mean frontal plane T wave axis shifted markedly leftward on standing, with T wave axis less than or equal to 0 degrees in 16 (44%) of the subjects with MVP vs. only 2 (7.4%) of the control group, while the QRS-T angle widened to more than 60 degrees in 18 (50%) of those with MVP. Marked left axis deviation of the T wave on standing with T wave axis less than or equal to -30 degrees was found only in subjects with MVP, and their QTc interval was longer, P less than 0.05. In 11 subjects with mitral valve bowing or rounding on the echocardiogram (i.e., less than 2 mm posterior mitral valve displacement), intermediate grades of T wave axis shifts were seen.

Trauma to the back from the force of chronic stress is thought to be an etiologic factor in isthmic spondylolisthesis (SLL). The relationship of first degree spondylolisthesis to low back pain (LBP) is controversial. We compare the prevalence of SLL in helicopter pilots who are subject to strong vibrational forces, with other airforce personnel. Helicopter pilots had more than a four times higher prevalence of SLL (4.5%) than did cadets (1.0%) and transport pilots (0.9%). Low back pain was more frequent in pilots with SLL than in those without this lesion but in no case was the pain disabling or the defect progressive. We conclude that SLL may be induced by vibrational forces and although SLL is associated with LBP, the pain was little clinical significance.

The records of 719 male air force personnel, aged 18-30 in 1968, were searched for the results of the systolic blood pressure (SBP), and height and weight examinations at entry in 1968 and after 12-15 years follow-up. The body mass index (BMI = weight/height2) was calculated and an elevated value was defined as one in the upper quintile. An elevated blood pressure, defined as an SBP greater than or equal to 140 mm Hg, was found on follow-up in 4.7% of the entire cohort, in 6.0% (4/67) of those with an elevated SBP and a normal BMI at entry, in 10.2% (12/117) of those with a normal SBP and an elevated BMI at entry, and in 20.0% (7/35) of those with both elevated BMI and SBP greater than or equal to 140 mm Hg at entry. Of those with a normal SBP and BMI at entry, 2.2% (11/500) had an elevated SBP on follow-up. We conclude that BMI in young men can predict SBP 12-15 years later, and that this predictive value is at least as high as that of the resting blood pressure.

Time of useful consciousness (TUC) was determined in 17 subjects exposed twice to 25,000 ft (7,620 m) in an altitude chamber. The criterion for TUC determination was inability to add two-digit numbers correctly. Median values of TUC were 267.5 seconds (s) in the first exposure and 240 s in the second. The intraindividual variability between the two exposures was 40.6 s. The probability of remaining in "useful" consciousness as a function of time at 25,000 ft (7,620 m) was similar in both exposures. The need for a more scientific approach towards the determination of time of useful consciousness in simulated high altitudes is raised.

The medical files of a sample of men who had been followed by annual examinations from 1968 through 1978 were selected, using a random number sequence from the records of the Israel Air Force. One group of 430 men, ages 21-23 at entry, and a second group of 264 men, ages 25-28 at entry, were studied. The results of the urinalysis at entry and after ten years of follow-up were recorded. The point prevalence of all degrees of microhematuria increased significantly with age in both groups. One to three or more red blood cells (RBCs) per high-power field (HPF) were found in 3.5% of the subjects ages 21-23 at entry and in 14.2% in the same subjects ten years later (P = 0.001). Similarly, one to three or more RBCs per HPF were found in 4.9% of men ages 25-28 at entry and in 11.7% of the same subjects ten years later (P = 0.001). The authors conclude that age needs to be taken into consideration in drawing the line between physiologic and pathologic microhematuria.

Little has been reported concerning electrolyte changes among patients with mesothelioma. Two studies have suggested that hyponatraemia is particularly common among them and should lead to suspicion of inappropriate secretion of antidiuretic hormone in those patients (Perks et al. 1979; Siafakas et al. 1984). We reviewed serum electrolyte changes in three groups of patients: 48 cases of pleural mesothelioma, 89 of peritoneal mesothelioma, associated with asbestos exposure, and 149 of asbestosis. Five of 48 (10.4%) patients with pleural mesothelioma, 17 of 89 (19.1%) with peritoneal mesothelioma, and 23 of 149 (15.4%) patients with asbestosis without mesothelioma, had hyponatraemia. No statistically significant difference among the groups was found. These findings do not support the proposal that hyponatraemia is unusually common when mesothelioma is present, at least not among patients whose neoplasms are related to asbestos exposure.

Pilots of the AH-1S helicopter maintain a vertical sitting position in the gunner's position (front seat), whereas in the pilot's seat (rear), they lean forward and to the left in order to operate the controls. A cross over study with pilots flying alternately in the front and rear positions was used to assess the effect of crew position on the prevalence of low back pain during flight. In the pilot's seat, there was an increased prevalence of pain (72.2%, 13/18 versus 55.6%, 10/18); the onset of pain was quicker than experienced in the gunner's position (64.3%, 9/14 versus 7.1%, 1/14, p less than 0.001); and the intensity was greater (85.7%, 12/14 versus 7.1%, 1/14, p less than 0.001). We conclude that posture is an important component of the low back pain experienced by helicopter pilots during flight.

The medical reasons for rejection among 3,000 consecutive applicants for flight training were evaluated, and the effectiveness of the screening process determined by reviewing subsequent medical wastage occurring during flight training. Of the 46 cadets who left the course because of medical reasons, 8 withheld information which would have led to their rejection on the original screening examination (epilepsy 1, recurrent syncope 1, migraine headache 2, Crohn's disease 1, asthma 1, chronic knee pain 1, and chronic recurrent headaches 1). There were also two errors in medical processing. The other 36 cases could not have been predicted by current screening procedures. We conclude that the major deficiency in our screening process is the concealment or withholding of information by candidates for flight training.

The visual acuity of 38 helicopter pilots experiencing serious air accidents was compared to that of a control group of 72 pilots, matched for age, aircraft, and hours of flight. Decrease in visual acuity was divided into two groups: 1) minor decreases in vision up to 20/25 (not requiring corrective lenses); and 2) visual acuity of 20/30 or less with correction to 20/20. Minor decreases in visual acuity were found in 23.7% (9/38) of those in the accident group compared to 25.0% (18/72) in the control group. There were more pilots in the control group who needed corrective lenses (12.5% (18/72) versus 2.8% (1/38), p less than 0.07). We conclude that helicopter pilots with corrective lenses or minor uncorrected decreases in visual acuity are not at increased risk for serious air accidents.

Aeromedical evacuation has been extensively used by military forces for evacuation of wartime casualties, but has also proven useful in civilian disaster response. In contrast to the broad coverage of the clinical aspects of the aeromedical evacuation, the operational and management control issues have rarely been addressed. The sophisticated battlefield of the 1980s has had an impact also in air evacuation, adding to the factors to be considered before launching an evacuation mission. The professional control of aeromedical evacuation is, therefore, crucial to the efficient and smooth operation of this high-cost resource. In an attempt to shed light on some of the operational perspectives of military air evacuation, the Israeli experience in the management control of such systems is discussed.

The daily fluctuations in the levels of some physiological and performance parameters have been assessed in three young subjects. The assessment was carried out before and after exposing them to the combined effect of two stressors, reduced barometric pressure and hypoxia. The exposure was effectuated by a simulated flight in a low pressure chamber for 30 min. The measured altitude in the chamber was 25000 ft (7620 m). During the simulated flight, each of the individuals experienced 2-3 min of hypoxia. The examined parameters (oral temperature, peak expiratory flow, grip strength, 2 and 6 digits recognition test, addition, counting backward, and odd-even addition test) exhibited circadian rhythms whose acrophases shifted significantly after exposure to the combined effect of the two stressors. The phases continued to shift for 4 d in a concordantly synchronized pattern. On the fourth day, they exhibited a tendency to resume their original phase.

Pilots were examined in order to determine whether the cumulative incidence or point prevalence of asymptomatic microscopic hematuria is associated with air duty. The cumulative incidence of recurrent microscopic hematuria over a 12-15-year period was 11.3%(17/151) in fighter pilots, 10.0%(8/80) in helicopter pilots, and 13.8% (11/80) in transport pilots. Similarly, the point prevalence of microscopic hematuria in those who had flown the day prior to the urinalysis was no higher than found in the control group. We conclude that air duty does not cause microscopic hematuria either chronically or during the day after the stress of air flight.

The efficacy of transdermally administered scopolamine was compared with the efficacy of oral dimenhydrinate and placebo therapy in the prevention of motion sickness at sea. Medication was administered on a controlled double blind basis to 140 subjects. A placebo effect reduced the motion sickness incidence (MSI) from 57.69% in the control group to 43.47%. Administration of dimenhydrinate reduced the MSI to 22.22% and the use of Transdermal Therapeutic System Scopolamine (TTSS) further reduced the MSI to 16.66%. TTSS afforded 61.67% protection against motion sickness at sea, compared to 48.88% protection with dimenhydrinate.

Mitral leaflet motion during systole was studied by echocardiography in 102 healthy young men. Mean posterior maximal leaflet motion was 2 +/- 1 mm behind the CD line on 2-dimensionally (2-D) directed M-mode examination. On the apical 4-chamber cross-sectional view a mean area of 0.34 +/- 0.24 mm2 was contained by the mitral leaflets above the plane of the mitral anulus. Elevated values on the M-mode view (greater than or equal to 4 mm) compared with the 2-D 4-chamber view (greater than or equal to 0.70 mm2) were discordant, with 90% (18 of 20) of the elevated values found in 1 view only. Thus, there is a wide spectrum of mitral leaflet motion in asymptomatic young men. The value of the echocardiogram in diagnosis of mitral valve prolapse is questionable because any cutoff point between normal and abnormal is arbitrary and the degree of motion has not been shown to correlate with morbidity or mortality.

As the number of military pilots over the age of 40 increases, open-angle glaucoma becomes an important aeromedical problem. Epinephrine ophthalmic solution is the only antiglaucomatotic agent in use among flying personnel. Timolol maleate, a new antiglaucomatotic agent, is a nonselective beta-blocker. This drug has a potent hypotensive effect on intraocular pressure with a minimal effect on visual functions. Our data show that it significantly decreases the pulse rate and may eventually be a basis for cardiac dysrythmias.

Transdermal scopolamine has been reported to provide protection against motion sickness, both while sailing at sea (7-8 h) and under experimental conditions. In this study, we tested the efficacy of transdermal scopolamine and evaluated its side effects during a 72-h cruise at sea. We tested 38 male volunteers, 20-25 years old, who were located on a 3000-ton vessel. The presence of seasickness, defined by Graybiel's diagnostic criteria, was used to calculate percent protection. When sickness was considered as malaise II or more, the drug provided 74, 73, and 39% protection during the three sailing days, respectively. There were no significant differences in the magnitude of the side effects reported by experimental and placebo groups. We conclude that transdermal scopolamine's efficacy against seasickness during a 3-day cruise was not associated with significant side effects and, therefore, we find the drug suitable for long-term use by sailing crews.

The epidemiology of sudden death, the etiology of inflight sudden incapacitation, and the influence of pilot age and experience on air accident rates are reviewed in order to determine the aeromedical emphasis needed to minimize accidents. Sudden deaths in men over age 35 are nearly all due to coronary artery disease, whereas in those under 35 years they are mostly due to hypertrophic cardiomyopathy. The incidence of fatal accidents from human error is, however, far greater than that from physical illness. Since inexperienced pilots have a 2-3 times increased incidence of mishaps due to pilot error, the estimated risk of disease related in-flight sudden incapacitation should be balanced by consideration of pilot experience. Therefore, it may be preferable to grant waivers to experienced pilots with an increased incidence of disease-related inflight sudden incapacitation than to replace them with novices. We conclude that overly strict medical criteria may paradoxically increase accident rates.

The medical records of 1000 asymptomatic male air force personnel were examined retrospectively for the results of 15 yearly examinations of urinary sediment. The study covered the period 1968-82, beginning with the subjects aged 18-33 years. The cumulative incidence of two to four or more red blood cells per high power field found at one or more examinations was 38.7% after an average of 12.2 yearly examinations per person. In 161 subjects two to four or more red blood cells per high power field were found at two or more yearly examinations within a five year period. Intravenous pyelography in 58 cases disclosed asymptomatic nephrolithiasis in six. Cystoscopy performed in 11 cases identified one patient with urethritis, one with a vesical calculus, and one with transitional cell carcinoma of the bladder. Two years before diagnosis the patient with carcinoma had had a single transient finding of 10-12 red blood cells per high power field which was not investigated further. Cystoscopy was performed after an episode of macroscopic haematuria. Renal biopsy in one subject with recurrent microhaematuria and trace proteinuria disclosed focal glomerulonephritis. None of the remaining subjects with microhaematuria developed hypertension or proteinuria, and at the end of the study period all were active and free of urinary symptoms. The observed cumulative incidence of urological neoplasms at 15 years (0.1%) was consistent with that expected in Israeli men aged 18-40 (0.09%). Hence microhaematuria detected during a screening examination probably should not be regarded as a specific sign of a significant lesion and does not of itself warrant urological investigation in adults aged 40 or less.

Malignant mesothelioma has been rare in the general population. In recent decades its incidence has risen dramatically, parallel to the increasing use of asbestos in industry since 1930. Altogether 17,800 asbestos insulation workers, members of the International Association of Heat and Frost Insulators and Asbestos Workers (AFL-CIO-CLC) in the United States and Canada, were enrolled for prospective study on 1 January 1967 and followed up to the present. Every death that occurs is investigated by our laboratory. One hundred and seventy five deaths from mesothelioma occurred among the 2221 men who died in 1967-76 and 181 more such deaths in the next eight years. Altogether, 356 workers had died of malignant mesothelioma (pleural or peritoneal) by 1984. Diagnosis of mesothelioma was accepted only after all available clinical, radiological, and pathological material was reviewed by our laboratory and histopathological confirmation by the pathology unit made in each case. One hundred and thirty four workers died of pleural and 222 of peritoneal mesothelioma. Age at onset of exposure, age at onset of the disease, and age at death were similar in both groups of patients. Significant difference was noted only in the time elapsed from onset of exposure to the development of first symptoms, which was longer in the group with peritoneal mesothelioma. Shortness of breath, either new or recently increased, and chest pain were the most frequent presenting symptoms in the group with pleural mesothelioma; abdominal pain and distension were frequent in the patients with peritoneal mesothelioma. Pleural effusion or ascites were found in most patients. The most effective approach to the diagnosis of malignant pleural mesothelioma in these cases was by open lung biopsy; exploratory laparotomy was best for diagnosing peritoneal mesothelioma. Patients with pleural mesothelioma died principally from pulmonary insufficiency whereas those with peritoneal mesothelioma succumbed after a period of pronounced wasting.

The degree of systolic movement of the tricuspid valve (TV) leaflets was measured in 100 consecutive apparently healthy men 18-20 years old at the time of maximum posterosuperior motion toward or into the right atrium. Backward bowing of greater than 0.20 mm2 of the anterior leaflet, and greater than 0.15 mm2 of either the posterior or septal leaflets beyond the plane of the tricuspid annulus was found in 5% or less of the cohort irrespective of the echocardiographic view in which it was recorded. The upper 5% of these young men had greater than 0.80 mm2 of backward bowing when the leaflet motion was summed from all three views. The anterior leaflet demonstrated more bowing than either the septal or posterior leaflets. The systolic TV prolapse area correlated highly with the degree of mitral leaflet prolapse (r = 0.654, p less than 0.001). We conclude that there is a wide continuous spectrum of tricuspid valve leaflet prolapse area in healthy young men. This quantitative approach may help standardize the echocardiographic evaluation of tricuspid leaflet motion.

The extent of posterior mitral leaflet motion (PMLM) during systole in relation to age was studied in 300 asymptomatic men aged 18-42 years. PMLM of 4 mm or more on two-dimensional directed M-mode echocardiography was found in 8% (16/200) of subjects under age 35 years, but in only 2% (2/100) of those aged 35 years or more (p less than 0.05). On two-dimensional echocardiography, 16% (31/200) of men under 35 years old had PMLM greater than or equal to 0.40 mm2 compared with 1% (1/100) of those 35 years or more (p less than 0.001). The findings were not related to differences in left ventricular cavity dimensions or in the extent of systolic ventricular contraction. Body mass index (BMI) increased with age, but there was a significant and independent negative correlation of age with PMLM after controlling for BMI. The data are compatible with the hypothesis that the aging process is associated with decreased mobility of the mitral valve or annulus with lesser degrees of backward bowing or billowing of the leaflets during systole. Age should be taken into account in determining "normal" values for mitral leaflet motion.

There were 21 pilots followed for 12-131 months in order to determine the natural history of spondylolithesis (SLL). Of these 21, 16 had follow-up X-ray examinations, and only 1 was found with significant progression of the posterior vertebral displacement. Of the 12 pilots with SLL and low back pain (LBP), 4 had recurrent single episodes of acute LBP, but all remained active and continued to fly over the follow-up period. None of the 9 pilots who had SLL discovered on routine X-ray examination developed LBP over the follow-up period. We conclude that pilots with SLL can continue to fly with minimal risk of morbidity and loss of flight time.