Showing papers in "Journal of Occupational and Environmental Medicine in 1985"

Occupational low-back pain in hospital nurses.

Abstract: A survey of hospital staff nurses of a large tertiary care hospital was performed to investigate occupational low-back pain. Attack rates of 41% (37% "occupational") and 52% (occupational) were found using recall periods of two weeks and six months, respectively. Comparison with a control group suggests the validity of the work-relatedness of low-back pain in nurses. Factors associated with the disorder were also investigated, with results showing no differences due to nursing division assignment but significant association with specific tasks.

Obtaining occupational exposure histories in epidemiologic case-control studies.

Abstract: In a large population-based case-control study designed to generate hypotheses regarding possible associations between cancer sites and occupational exposures, an innovative methodology is utilized to infer the subjects' chemical exposures. It features (1) a probing interview to obtain a detailed portrait of each job the subject has held, (2) exposure coding by a team of chemists and hygienists who review each interview, (3) a coding checklist of nearly 300 occupational exposures including the most common ones, and (4) indication by the coders of the level, frequency, and mode of exposure, as well as of their degree of confidence that the exposure occurred. In making coding decisions, the chemists draw upon their experience and upon consultants and bibliographic sources. Resultant data can be combined to produce a variety of semi-quantitative indices of exposure for epidemiologic analyses.

Occupational exposure to electromagnetic fields and the occurrence of brain tumors. An analysis of possible associations.

Abstract: To explore the association between occupation and the occurrence of brain tumor, an epidemiologic study was conducted using data from the death certificates of 951 adult white male Maryland residents who died of brain tumor during the period 1969 through 1982. Compared with the controls, men employed in electricity-related occupations, such as electrician, electric or electronic engineer, and utility company serviceman, were found to experience a significantly higher proportion of primary brain tumors. An increase in the odds ratio for brain tumor was found to be positively related to electromagnetic (EM) field exposure levels. Furthermore, the mean age at death was found to be significantly younger among cases in the presumed high EM-exposure group. These findings suggest that EM exposure may be associated with the pathogenesis of brain tumors, particularly in the promoting stage.

Exposure to anesthetic gases and reproductive outcome. A review of the epidemiologic literature

Abstract: A variety of evidence suggests that chronic exposure to low doses of anesthetic gases, as occurs in the occupational setting, is a risk factor for spontaneous abortion and congenital defects. The major epidemiologic studies are reviewed, and it is suggested that, due to significant flaws in the design and conduct of these observational studies, there is inadequate evidence to conclude that occupational exposure to anesthetic agents causes increased rates of spontaneous abortion or congenital anomalies.

Work-site health promotion. Five-year trend in employee health care costs.

Abstract: Participants in work-site health promotion programs are compared with other employees at the same work-site in terms of health care utilization as measured by insurance claims. Participants tended to incur higher health care costs than nonparticipants for the six-month period after the program began. However, a cohort analysis of one of the groups shows that participants' costs declined in relation to nonparticipants' for subsequent periods. Overall, for 4.75 years after the program, participants averaged 24% lower health care costs than nonparticipants. The imputed savings in health care costs exceeds program costs for this cohort by a factor of 1.45. The findings substantially strengthen the conclusions of other controlled studies that work-site health promotion reduces health care costs.

A computer-administered neurobehavioral evaluation system for occupational and environmental epidemiology. Rationale, methodology, and pilot study results.

Abstract: To facilitate the conduct of epidemiologic studies of populations at risk for or suffering from central nervous system (CNS) dysfunction due to environmental agents, a computer-administered neurobehavioral evaluation system has been developed. The system includes a set of testing programs designed to run on a microcomputer and questionnaires to facilitate interpretation of results. Standard tasks evaluating memory, psychomotor function, verbal ability, visuospatial ability, and mood were selected and adapted for computer presentation following the recommendation of an expert committee of the World Health Organization and the National Institute for Occupational Safety and Health. In two pilot surveys, test performance was found to be influenced by age, education level, and socioeconomic status in ways consistent with prior research findings. Performance on tests of short-term memory and reaction time was negatively correlated with intensity of organic solvent exposure among industrial painters. In view of the ease of administration and data handling, high subject acceptability, and sensitivity to the effects of known neurotoxic agents, computer-based assessment of CNS function holds promise for future epidemiologic research.

Health implication of occupational exposures to hydrogen sulfide

Abstract: A five-year retrospective study of workers exposed to hydrogen sulfide in Alberta, Canada, was conducted, using the records of 250 workers who submitted claims to the provincial compensation board from 1979 through 1983. Fifty-four percent of the exposed workers became unconscious after exposure. Signs and symptoms with a neurological component accounted for the largest group of clinical findings. Respiratory and ophthalmologic effects were the other major groups of signs and symptoms. The overall fatality rate was 2.8%, significantly lower than that reported (6.0%) in a similar study a decade earlier. This is attributed to improved first-aid training and increased awareness of the dangers of hydrogen sulfide. Traumatic injury as a result of a fall after exposure was noted in 31 cases.

Program for increasing health and physical fitness of fire fighters.

Abstract: In 1970 the Los Angeles County Occupational Health Service began a program to monitor the health status and to increase the physical fitness of its 1,800 fire fighters. By 1973 physical examinations including resting ECG and blood laboratory studies had been completed for all fire fighters. In addition, the oldest 998 fire fighters were tested for physical work capacity (PWC), job-related strength performance, and spine flexibility. Exercise prescriptions and health enhancement counseling were given by exercise physiologists at the time of testing, and one hour per shift was assigned for the exercise. Data were not kept to determine compliance with the exercise program but physical activity was evaluated by interview and the same physiological measurements were made at each examination. By 1982 departmental averages for PWC had increased 16%, with the oldest age group (older than 50 years) showing the most marked improvement. The percentage of habitual smokers decreased from 44% to 25%. High levels of PWC, strength, and flexibility were found to be inversely related to workers' compensation costs. Fire fighters with below-average PWCs subsequently experienced 2.6 times more myocardial infarctions than their above-average counterparts. While it is difficult to determine the influence of any one factor on the collective wellbeing of the fire fighters, it is logical to assume that this program has had an important beneficial effect on the maintenance of a healthy work force.

Effects of an SCBA on breathing pattern, gas exchange, and heart rate during exercise.

Abstract: The effects of a pressure demand-type self-contained breathing apparatus (SCBA) (total weight, 15.5 kg) on breathing pattern, gas exchange, and heart rate were studied in 13 firemen. The subjects performed sequential progressive exercise tests on a treadmill both without and with an SCBA. The use of an SCBA consistently limited tidal volume. During submaximal exercise oxygen consumption and heart rate increased remarkably more with the SCBA than without it. Four subjects reached their maximal heart rate with the SCBA. Their mean ventilation rate was 68% and oxygen consumption was 83% of the maximal values attained without the SCBA. The shoulder harness of the heavy SCBA prevented free motion of the thorax, affecting the regulation of breathing, and thus seriously disturbed ventilation and gas exchange, particularly at heavier exercise levels.

Respiratory illness in the construction trades: I. The significance of asbestos-associated pleural disease among sheet metal workers

Abstract: To assess the rate of roentgenographic and lung function abnormalities in asbestos-exposed construction workers, the authors studied 314 white male members of a local sheet metal workers union. Health outcomes were assessed by questionnaire, simple spirometry, and chest roentgenography; data were collected and interpreted following guidelines of the American Thoracic Society and the International Labor Office. Analyses of union records showed the tested population to be representative of all those eligible for testing. Pleural abnormalities were common, increasing to a prevalence of approximately 70% in workers with more than 30 years employment. Roentgenographic evidence of pleural disease was significantly correlated with decreased forced vital capacity (p = 0.027) after controlling for the potential confounding effects of age, height, cigarette consumption history, and employment duration. In contrast, forced expiratory volume in 1 s showed a stronger association with amount smoked (p = 0.022) than with pleural abnormality (p = 0.316). Logistic regression analyses showed that cigarettes act to increase the effect of asbestos in causing pleural disease among exposed workers. Cigarettes, in the absence of significant asbestos exposure, do not appear to cause pleural disease. The authors conclude that construction workers, such as those described herein, have a considerably increased rate of pleural disease, which has functional significance in view of the correlations noted with forced vital capacity measurements. Therefore, pleural disease in asbestos-exposed workers is not only an indicator of exposure but also an indicator of early impairment of pulmonary function.

Formaldehyde exposure in a gross anatomy laboratory

Abstract: A gross anatomy laboratory for medical students was evaluated for formaldehyde levels throughout its eight-week term. Results indicated that exposures for students and instructors were below the 3-ppm permissible exposure limit (assuming a maximum of five hours of daily exposure) established by the Occupational Safety and Health Administration. However, about one third of the eight-hour time-weighted-average exposures were greater than 1 ppm under the same assumptions. Exposure levels for students and instructors did not differ. Exposures tended to decrease over the term unless internal cadaver cavities were being dissected. These exposures are significant in light of the recent implication of formaldehyde as an animal carcinogen and the trend to reduce permissible levels to 1 ppm or lower.

A work-site weight control program using financial incentives collected through payroll deduction

Abstract: In a work-site weight control program using a self-motivational program of financial incentives implemented through payroll deduction, 131 university employees chose weight loss goals (0 to 60 lb) and incentives (+5 to +30) to be deducted from each paycheck for six months. Return of incentive money was contingent on progress toward weight goals. Participants were assigned randomly to one of four protocols, involving group educational sessions v self-instruction only and required v optional attendance at weigh-ins and sessions. Overall, dropout rates (21.4%) and mean weight loss (12.2 lb) were encouraging, especially compared with those of other work-site programs. Weight loss was positively associated with attendance at weigh-ins and educational sessions. However, requiring attendance did not increase program effectiveness and seemed also to discourage enrollment among men. The weight control program was equally effective when offered with professionally led educational sessions or when accompanied by self-instructional materials only.

Comparative effectiveness of topical treatments for hydrofluoric acid burns.

Abstract: Hydrofluoric acid (HF) burns are characterized by progressive tissue necrosis and severe pain. Numerous topical treatments have been proposed, yet few have been studied experimentally. The present study was designed to examine the comparative efficacy of recommended treatments. Hair on the hind legs of rats was removed and 48 hours later 70% HF was applied. Calcium gluconate, Zephiran (benzalkonium chloride), A + D Ointment, aloe gel, and magnesium ointment were applied topically and burn development was monitored. Calcium gluconate significantly reduced burn size as early as one hour after application. Significant protection continued for seven days after the single application. The other treatments were not effective in decreasing or delaying HF burn development. The results indicated that calcium gluconate ointment was the most effective topical treatment for HF burns.

Can glycosylated hemoglobin be a job stress parameter

Abstract: Glycosylated hemoglobin (HbA1c) levels are evaluated as a possible integrated measure parameter of chronic job stress. HbA1c and fasting blood glucose levels in 100 healthy male printing workers (pressmen) exposed to noise, rotating shifts, and overwork were compared with levels measured in 200 healthy male clerical workers not exposed to those stressors. While blood glucose levels and their variability were found to be approximately the same in both groups, HbA1c levels were found to be 8.64% higher among the pressmen and this difference was significant at p less than .001. These findings support the hypothesis, and further research to confirm the test is suggested.

Relating posture to discomfort in VDT use.

Abstract: To identify sources of discomfort in video display terminal (VDT) work stations, the working postures of 100 telephone operators who used VDTs to retrieve directory listings were photographed. Attempts to correlate postural angles and distances derived from the photographs with subjective judgments of physical discomfort reported on a questionnaire were unsuccessful. Possible explanations for the failure of the postural parameters to predict discomfort are discussed, and the absence of other postural data that may be appropriately applied to the specification of VDT work stations is noted. It is concluded that recommendations for VDT work stations that are phrased in terms of static angles and distances are currently unsubstantiated and, thus, are not yet ready to be codified as formal standards.

Epidemiologic study of workers exposed to acrylonitrile: an update.

Abstract: A previous report presented the cancer morbidity and mortality experience through 1976 of a cohort of 1,345 male employees with potential for exposure to acrylonitrile at a fibers-producing plant. This study has now been updated through 1983 for cancer incidence and through 1981 for mortality. Overall, 43 cancer cases have occurred, with 37.1 expected based on company rates. A previously reported excess number of cases of lung cancer remains, but is not as marked (10 observed, 7.2 expected). Prostate cancer cases were significantly in excess, with six cases observed and 1.8 expected. Mortality analyses revealed 36 cancer deaths, with 31.6 expected. Of these, 14 were from lung cancer, with 11.6 expected based on company rates. Only one death from prostate cancer occurred, with 1.0 expected. To our knowledge, prostate cancer excesses have not been reported in any other acrylonitrile studies, and hence their significance is currently difficult to assess.

Comparison of crude and smoking-adjusted standardized mortality ratios.

Abstract: To systematically evaluate bias in estimating relative risks associated with occupational exposures obtained in the absence of smoking data, the authors compared crude and smoking-adjusted standardized mortality ratios for selected occupations using data from a study of U.S. veterans. Crude and smoking-adjusted SMRs were highly correlated: lung cancer (r = .88), bladder cancer (r = .98), and intestinal cancer (r = .97). Greater differences occurred for lung cancer, which is more strongly related to smoking than bladder or intestinal cancer.

Respiratory function and exposure-effect relationships in wood dust-exposed and control workers.

Abstract: The effect of wood dust exposure on 50 cabinet makers was examined. Woodworkers reported more nasal and eye symptoms and more cough, sputum and wheezing than did 49 control workers. More irritated cells were present in the woodworkers' nasal cytological smears. In contrast to the control workers, the woodworkers had a significant decline in lung function over the workshift. An inverse correlation between baseline lung function and an exposure index (mean area dust level multiplied by length of exposure) was demonstrated in the woodworkers. Greater dust exposure was not associated with larger falls in lung function over the work shift.

Part-time employment and women's health.

Abstract: The relationships between part-time employment and self-reported health are analyzed for a national probability sample of middle-aged women. Overall, there was a tendency for full-time workers to have the best health, part-time workers to have an intermediate level of health, and women who were not in the labor force to have the poorest health. However, the pattern varied by race and marital status. For married black women, part-time workers reported poorer health than full-time workers. This appeared to be due in part to the lower socioeconomic status of the black part-time workers. For married white women, there was little or no difference in health or socioeconomic status between part-time and full-time workers. Additional hypotheses and relevant evidence are presented.

Excess leukemia in a refinery population.

Abstract: A retrospective follow-up mortality study of white male employees of an oil refinery located in southern illinois revealed a statistically significant excess number of deaths due to leukemia compared with the experience of U.S. white males (standardized mortality ratio [SMR] = 213; 95% confidence interval [Cl], 117 to 358). The excess was due mainly to acute myeloid leukemia (AML) (SMR = 394; 95% Cl, 172 to 788). From 1973 to 1982, fourteen leukemia deaths were identified; eight of the cancers were of the AML cell type. The work histories of the decedents were examined for the potential for benzene exposure. Although specificity of the work histories was limited, the investigation has shown that the subjects did not work in jobs identified as having the highest benzene exposures. At this time, the excess leukemia remains unexplained.

Activity level of mother's usual occupation and low infant birth weight.

Abstract: Previous studies of the effect of mother's employment on infant birth weight have shown mixed results. This study was designed to explore the relationship between activity level of a woman's occupation and her risk of delivering a low-birth-weight infant. Using 1981 state of Washington birth certificate records, the authors selected 5,822 subjects. Case subjects were women who had delivered infants weighing 2,500 g or less; controls were those who had delivered normal-weight infants. Women were grouped into five activity levels based on their usual occupation. No association was detected between activity level of mother's usual occupation and delivery of a low-birth-weight infant. These data suggest that active work is not associated with an increased risk of having a low-birth-weight baby.

The healthy worker effect on morbidity rates

Abstract: Studies relating mortality and occupation are difficult to interpret because of the "healthy worker effect." That effect is primarily due to the fact that individuals entering the labor force are in reasonably good health. A similar phenomenon might be expected in a comparison of morbidity among members of an occupational group with that of the general population. A comparison of morbidity among different population and occupation groups is made possible through the Household Interview Survey (HIS) of the National Center for Health Statistics. Data from the HIS for the years 1969 through 1974 were combined to form a sample classified according to race, sex, age, occupation, and occurrence of various health conditions. Among subjects between 25 and 59 years of age, age-specific morbidity ratios and standardized morbidity ratios were computed for blue-collar and professional/managerial employees and for unemployed who were either seeking or not seeking employment. There appears to be a "healthy worker morbidity effect" for chronic, but not for acute, conditions just as there is for mortality. The healthy worker effect for chronic morbidity maintains itself and, in fact, appears to increase throughout the 35-year period of stable employment. The age-specific morbidity ratio may have considerable theoretical importance for evaluating the related mortality experience of employed populations.

Effect of shiftwork on canteen food purchase.

Abstract: Shiftwork has the potential for altering food intake patterns in ways that may be unfavorable to health. In two industrial plants in the Australian state of Victoria where food had to be brought from home or purchased on the job, the effect of shiftwork on food sources as well as the energy density of food items was assessed. In the steel plant, employees on the afternoon shift had relatively more principal eating occasions on the job than did day or night shift workers. The canteen did not cater adequately for the meal needs of employees, who used the vending machines to a greater extent when on the afternoon shift than on other shifts. In the aluminum plant, workers who depended on food from home alone ate relatively less energy-dense foods than did workers who included canteen foods in their diets. Use of lower-energy density items was greater on the day shift than on the afternoon shift, and in turn was greater on that shift than for the night shift. After a one-year nutrition education program, the use of lower-energy density items increased on the day and night shifts. Thus, it was found that food usage could be influenced not only by shiftwork, but also by the food facility available on site and by a nutrition education program.

A retrospective mortality study of workers in three major U.S. refineries and chemical plants. Part 1: Comparisons with U.S. population.

Abstract: A dynamic retrospective cohort study was performed to examine the mortality experience of 21,698 workers at Exxon's refineries and chemical plants in Baton Rouge, La.; Baytown, Tex.; and Bayway/Bayonne, N.J. Included were 15,437 regular employees who worked at least one month during the period Jan. 1, 1970, through Dec. 31, 1977, and 6,261 retirees who were alive as of Jan. 1, 1970. There were 137,702 person-years of observation. Mortality in this total study population was generally lower than that of the U.S. population. Study follow-up was complete for 98.7% of the study population. The standardized mortality ratio for the 3,198 deaths was 91, while that for deaths from all cancers (N = 666) was 94. Certain slightly elevated disease-specific mortality ratios, although not statistically significant, could be of biological importance and merit further review.

A retrospective cohort mortality study of iron ore (hematite) miners in Minnesota.

Abstract: In a retrospective cohort mortality study of 10,403 Minnesota iron-ore (hematite) miners no excesses of lung cancer mortality were found among either underground (Standardized mortality ratio [SMR] = 100) or above ground (SMR = 88) miners. Yugoslav-born miners incurred a two-fold significant excess mortality for lung cancer that did not appear to be associated with their mining exposures. Significant excesses in mortality due to stomach cancer were found for both underground (SMR = 167) and aboveground (SMR = 181) miners as compared with U.S. white males. However, except among Finnish-born miners, these excesses disappeared when comparisons were made with the appropriate county rate. The apparent absence of significant radon exposure, a strict smoking prohibition underground, an aggressive silicosis control program, and the absence of underground diesel fuel use may explain why these underground miners did not appear to incur the lung cancer risk reported in other studies.

Petroleum-related employment and renal cell cancer.

Abstract: The risk of renal cell cancer among those in occupations with potential for petroleum exposure was evaluated in a large population-based case-control study. Overall there was little difference between the cases and control groups in the proportion of persons with petroleum-related employment (odds ratio = 1.0). Among gasoline station attendants, a slight upward trend in risk was observed with increasing duration of employment. The significance of this association is not clear, but further research is needed in light of recent animal findings linking gasoline exposure to renal cancer.

A retrospective mortality study of workers in three major U.S. refineries and chemical plants. Part II: Internal comparisons by geographic site, occupation, and smoking history.

Abstract: A cohort of 21,698 U.S. refinery and chemical plant workers was observed for eight years to determine if there were interplant or other variations in causes of mortality. Plant populations in three geographic locations were combined to develop an internal standard for comparing subgroups within the total cohort. At no one geographic site were consistently different rates for all major causes of death observed. The adjusted mortality rates for potentially exposed workers were slightly greater than those for nonexposed workers for most causes examined. Smokers incurred a higher risk of mortality from many causes of death when compared with nonsmokers, regardless of occupational category. After controlling for smoking, there remained a slight excess in mortality for potentially exposed as compared with nonexposed workers.

Texaco mortality study. I. Mortality among refinery, petrochemical, and research workers.

Abstract: The Texaco mortality study is a retrospective follow-up study of all persons who were employed for at least five years in a refining, petrochemical, or research facility and who worked at some time during the period 1947 through 1977. Of the 19,077 white men in the cohort, 14,609 were alive, 4,024 were known to be dead, and the vital status of the remaining 444 was unknown as of Dec. 31, 1977. The standardized mortality ratio (SMR) of 75 for all causes was significantly low, on the basis of 5,332 expected deaths. Statistically significant deficits also were seen for all major causes of death and for cancer of many sites, including lung, stomach, bladder, and colon. The SMR was greater than 100 for six causes of death: pancreas cancer, brain cancer, leukemia, Hodgkin's disease, other lymphatic cancer, and benign neoplasms. However, none of these increases was statistically significant, and all SMRs except that for benign neoplasms (SMR = 148) were under 119.

Mortality of aluminum reduction plant workers, 1950 through 1977.

Abstract: The mortality experience of 5,406 men (cohort I) employed at one aluminum smelter on Jan. 1, 1950, and 485 men employed at a second plant (cohort II) on Jan. 1, 1951, is reported. For each man, the total number of years of exposure to tars, the number of years since first exposure to tars, and an index of exposure to tars expressed in tar-years were calculated. More than 99% of the men in the first cohort and 98% of the men in the second cohort were traced. Of the 1,539 men in cohort I who were deceased as of December 31, 1977, death certificates were obtained for 1,432 (93%). Of the 92 men in cohort II who were deceased as of December 31, 1977, death certificates were obtained for 80 (87%). The results showed that men in cohort I died of the following causes at approximately the same rate as or less frequently than men of similar age in the Province of Quebec: tuberculosis; circulatory disease; hypertensive heart disease; trauma; leukemia and aleukemia; and malignant neoplasms of the pancreas, genital organs, brain, intestine, and rectum and other abdominal areas. There were no deaths from pneumoconiosis or Alzheimer's disease. Although the observed and expected numbers of deaths in some of the cause-of-death categories were small, men in cohort I died of the following causes more frequently than did men of similar age in the Province of Quebec: respiratory disease; pneumonia and bronchitis; malignant neoplasms (all sites); malignant neoplasms of the stomach and esophagus, bladder, and lung; other malignant neoplasms; Hodgkin's disease; and other hypertensive disease. Mortality from malignant neoplasms of the bladder and lung was meaningfully related to numbers of tar-years and of years of exposure. Exposure-response relationships were less clear for malignant neoplasms of the esophagus and stomach and for other malignancies. Mortality from respiratory disease for men with 21 or more tar-years of exposure was approximately twice that of persons never exposed to tars. The apparent excess of other hypertensive disease was restricted to men never exposed to tars. Malignant neoplasm of the lung was the only cause of death in cohort II that was in excess of that expected at Quebec provincial rates.

Longitudinal study of grain elevator and control workers with demonstration of healthy worker effect.

Abstract: Changes in the respiratory symptoms and pulmonary function of 441 grain elevator workers and a control group of 180 civic workers during a three-year period were compared. The grain handlers who left their jobs during the interval between the first and second surveys were found to have shown a significantly higher prevalence of cough and shortness of breath at the beginning of the study period than those who remained employed; this difference was not observed among the civic workers. The grain and civic workers who were examined on both occasions showed similar longitudinal changes in their symptoms and pulmonary function. Nevertheless, the results of this study are biased by the healthy worker effect among the grain handlers.