Showing papers in "International Journal of Occupational and Environmental Health in 1997"

Shiftwork as a Risk Factor for Depression: A Pilot Study.

Abstract: This study explored the link between exposure to shiftwork and the prevalence of major depressive disorder (MDD) during and after the shiftwork experience. A geographically based random telephoning strategy was used to identify 98 current and former shift workers (31 women, 67 men, 40-65 years old, mean age 55.2 years). Each subject was then given, by telephone, two standardized psychiatric assessment instruments: the SCID to determine lifetime incidence of MDD; and the CES-D to evaluate current depressive symptoms. A modified version of the Standard Shiftwork Index (SSI) was also administered. In addition to confirming previous findings regarding the detrimental effects of shiftwork on sleep and social/domestic factors, there was an unexpectedly high prevalence of MDD identified, occurring during or after shiftwork, with a higher rate for women than for men. The study also provided suggestive evidence that increasing exposure to shiftwork (up to 20 years) was associated with an increased lifetime risk of MDD.

Work/Non-work Conflict and Health in Shiftwork: Relationships with Family Status and Social Support.

Abstract: This study examined work/non-work conflict and subjective health among female shift workers. Questionnaire data from 172 nurses were used to examine the effects of family status [single (S), living with partner (P), and living with partner and children (P + C)] and social support (from supervisors, co-workers, and family) on work/non-work conflict and health. Results indicated that work/non-work conflict was positively related to family status and negatively related to supervisor support. Psychological symptoms were related positively to work/non-work conflict and negatively to family support. Physical symptoms were related positively to work/ non-work conflict and negatively to co-worker and family support. Time-budget data from 24 nurses indicated that the P + C group spent more time on domestic work than the S and P groups and less time on leisure than the S group. Data collected from eight couples indicated that the nurses recorded more domestic work and less leisure than their male partners. The results indicate that work/non-work conflict is particularly salient for female shift workers living with a partner and dependent children, and highlight the importance of social support for this group of shift workers.

N-Acetyltransferase 2 (NAT2) and Glutathione S-Transferase μ (GSTM1) in Bladder-cancer Patients in a Highly Industrialized Area

Abstract: The study was designed to assess occupational and non-occupational risk factors in patients with urothelial carcinomas in an area of former coal, iron, and steel industries, with special regard to the impacts of polymorphic enzymes involved in the metabolism of aromatic amines (N-acetyltransferase 2, NAT2) and of polycyclic aromatic hydrocarbons (glutathione S-transferase μ, GSTM1). Inpatients with bladder cancer (N = 179) were interviewed for occupations ever engaged in for more than six months, and for bladder cancer risk factors in general. NAT2 was phenotyped by high-pressure liquid chromatography of caffeine metabolites in urine. The NAT2 status was additionally evaluated by genotyping 88 of these patients. Eighty-nine patients were genotyped for GSTM1. Of the 179 bladder-cancer patients, 115 (64%) were slow acetylators. In 70% of the subgroup of 89 patients, GSTM1 was negative, suggesting an impact of polycyclic aromatic hydrocarbons (PARs) in bladder-cancer carcinogenesis in the general pop...

Sleep Quality of Former Night-shift Workers.

Abstract: This study explored the relationship between past night-shift work and present quality of sleep, first by a survey and second with standard laboratory recordings. Nurses (n = 479) working on a day or evening schedule answered a questionnaire about past night-shift work and present quality of sleep. An insomnia index, derived from the questionnaire, was elevated for nurses who had worked more than five nights per month for four to ten years. The index was low for the 13 nurses who had worked more than ten years on night shifts. The sleep of 15 day nurses was recorded in the laboratory. Results showed that a high insomnia index was associated with a high number of awakenings, and that former night-shift workers had a significant reduction in slow-wave sleep, whether or not they had subjective sleep complaints. These results suggest that working at night may have persistent deleterious effects on sleep quality when the experience is long and includes a substantial number of night shifts.

Toxic Hepatitis from Dimethylacetamide

Abstract: Two cases of toxic hepatitis from dimethylacetamide (DMAC) occurred among 25 employees on a new acrylic-fiber production line at a western U.S. manufacturing plant. Interesting features of these cases include: 1) inadequate personal protective equipment (PPE) for dermal exposures, resulting in skin penetration during maintenance and repair procedures; 2) the subjects of these case reports are female; all workers at the manufacturer's European plant were male, and DMAC related liver dysfunction had not been encountered at that site; 3) the new American production line required more frequent maintenance and repair work than existing production lines at the European parent company, resulting in greater opportunities for DMAC exposure. Hepatotoxicity due to dermal absorption of DMAC and other amide-type solvents deserves special consideration in industrial settings.

Occupational Risk Factors for Breast Cancer among Nurses.

Abstract: A case-referent study nested in a cohort was used to evaluate occupational variables in the incidence of breast cancer among nurses. There were 59 cases and 118 randomly chosen referents. The participation rate was 97%. Odds ratios (ORs)and 95% confidence intervals (CIs)were calculated and the weights of potential confounding factors estimated by unconditional logistic regression. The odds ratio for breast cancer in a sister was 2.83 (95% CI 1.03-7.81). Specialization in pediatric, psychiatric, general (surgical and medical), geriatric, and primary care nursing, and "other kinds of nursing," gave an adjusted OR of 1.95 (95% CI 0.84-4.54). When working in different wards was accounted for, the highest adjusted ORs were found among nurses handling cytotoxic drugs, OR 1.65 (95% CI 0.53-5.17), and among pediatric nurses, OR 1.47 (95% CI 0.63-3.41); the lowest ORs were found among nurses in primary health care, OR 0.44 (95% CI 0.20-0.96). Analyses of the data stratified on age showed similar results. Occupational risks were not ascertained. Not only occupation but career-related life-styles should be taken into account in studies of health outcomes among working women.

Depression and Burnout in Hospital Health Care Professionals

Abstract: A cross-sectional study was conducted on a random sample of 1,200 health care professionals in Marseille, France, in order to assess the prevalences of depression and burnout, and to compare these two entities. Depression was assessed by the Center for Epidemiologic Studies-Depression scale (CES-D), and burnout by the Maslach Burnout Inventory (MBI). Burnout is a syndrome of emotional exhaustion, depersonalization towards patients, and reduced sense of personal accomplishment. Some psychiatrists consider burnout to be a clinical form of depression. The prevalences of depression and burnout were very close: 17.1% and 15.7% among the women, 19.4% and 22% among the men, but 6.5% of the women and 9.4% of the men were both depressive and burned-out. A correlation was found between the CES-D and the subscales Emotional Exhaustion and Depersonalization of the MBI. Multivariate analysis and logistic regression models showed that many demographic and subjective variables influenced depression and burnout in different ways.

Exposure to Organic Dusts, Endotoxins, and Microorganisms in the Municipal Waste Industry

Abstract: The waste-collection and -processing industry in Europe is developing rapidly due to environmental constraints in the direction of separate collection, processing, and recycling of waste. It is likely that this will lead to an increase in the number of workers involved in the handling and processing of municipal waste, and an increase in the number of workers exposed to organic dust. This paper reports the results of an occupational hygiene study of the waste-collection and -processing industry (a compost-screening facility, a resource recovery facility, and two waste-transfer facilities) in The Netherlands. It focuses on organic dusts, endotoxins, and microorganisms (total and gram-negative bacteria and fungi). Levels of exposure to inhalable organic dusts were highest in the waste-processing facilities (compost screening and resource recovery), with average concentrations for organic dusts up to 14.3 mg/m3 during manual separation of waste and 9.7 mg/m3 during compost screening activities. Pers...

Occupational Exposures to Asbestos in Brazil.

Abstract: European and Canadian asbestos companies have long taken advantage of the lack of regulation of the asbestos industry in developing countries, Their activities exploit vulnerable workers whose lack of medical care may result in silent epidemic of asbestos-related diseases, At this time, virtually all cases of asbestosis and asbestos, related cancers are not identified, reported, or compensated in developing countries. Brazil provides a compelling example of this growing problem. To stem the epidemic of asbestos-related diseases, Brazil, and many other countries, must adopt the total ban on asbestos use now in effect in more developed countries. Obstacles to accomplishing this in developing countries are daunting.

Shiftwork, Age, and Health: An Epidemiologic Investigation.

Abstract: The authors analyzed as a function of age the relationships between certain health problems and shiftwork, on the basis of a French epidemiologic study of health, work, and aging that included 21,378 subjects. Sleep disorders, Nottingham Health Profile data (energy, social isolation, emotional disorders), and health indicators such as the number of sick leaves, the condition of being overweight, and the use of neuropsychiatric drugs were affected by age and shiftwork (with additive effects for the two factors). The authors found no correspondence between work schedules and hypertension. The different types of shiftwork did not produce the same results: regular night work was better tolerated than night work included in a system of rotating shifts. Finally, there was a cumulative effect for age and shiftwork, with an increasing risk of crossing a threshold beyond which a schedule is no longer tolerated.

DNA-Protein Crosslinks and Sister Chromatid Exchanges as Biomarkers of Exposure to Formaldehyde.

Abstract: Formaldehyde is classified as a probable human carcinogen. DNA–protein crosslinks (DPCs) and sister chromatid exchanges. (SCEs) may represent early lesions in the carcinogenic process. The authors examined the OPCs and, SCEs in peripheral-blood lymphocytes of 12 and 13 workers exposed to formaldehyde and eight and 20 unexposed workers, respectively. The amounts of DPCs and SCEs in the exposed and the unexposed differed significantly after adjustment for smoking. There was a linear relationship between years of exposure and the amounts DPC and SCE. The authors conclude that the data indicate a possible Mechanism of carcinogenicity of formaldehyde, and that formaldehyde is mutagenic to humans. These results support the use of DPCs as a biomarker of occupational exposure to formaidehyde and to detect high risk populations for secondary prevention.

Infant Methemoglobinemia in the Transylvania Region of Romania

Abstract: The incidence of infant methemoglobinemia reported in three counties of Transylvania, Romania, was evaluated from medical records, field visits, and interviews. Well water was the main source of nitrate for induction of acquired infant methemoglobinemia, which occurred post-breast-feeding when the infants consumed nitrate-contaminated water used in mixing formula. The average age of reported infants with methemoglobinemia was 39 days, supporting earlier observations that infants less than 4 months old are the most susceptible segment of the population. Vitamin C, rather than methylene blue, was the main medical intervention in the Transylvania region. The mean incidence rates of methemoglobinemia in the three counties (Saut-Mare, Mures, and Bistrita-Nasaud) ranged from 24 to 363 per 100,000 live births over a five-year period (1990-1994). These rates are below earlier reported incidence rates of up to 13% (13,000 per 100,000 live births). Three selected case reports are presented to describe hospital/clinic data, well-water data, and infant feeding practices. Recommendations for appropriate intervention programs are described. The significances of possible physical and neuropsychological effects on the development of children following methemoglobinemia are discussed and the need for further investigations is outlined.

Relationship between Asbestos Exposures and 8-Hydroxydeoxyguanosine Levels in Leukocytic DNA of Workers at a Chinese Asbestos-material Plant

Abstract: The objective of the study was to evaluate the level of 8-hydroxydeoxyguanosine (8-OHdG) in DNA of peripheral-blood leukocytes as a biological marker of asbestos exposure and/or its fibrotic effects in an occupational population exposed to asbestos. The setting was a large-scale asbestos plant in China producing brake linings, asbestos rubber, and textile using chrysotile. From a base population of active and retired workers with various levels of cumulative exposure to asbestos and grades of asbestosis, 39 study subjects were randomly selected to reflect incremental grades of asbestosis based on Chinese diagnostic standards. They consisted of 19 "normal" (control) and ten "suspected" and ten "definite" asbestosis-grade subjects, group-matched for age and sex. Leukocytic DNA was extracted from 5-mL samples of peripheral blood and 8-OHdG level measured by high-pressure liquid chromatography. A cumulative asbestos exposure index (CEI) was calculated for each subject as the summed product of duration and level of asbestos exposure per job, incorporating a job-exposure matrix. Geometric mean 8-OHdG levels showed a positive gradient in relation to increasing grades of asbestosis (control: 1.78, suspected: 2.21, definite: 2.58), with a significant difference between the control and definite-asbestosis subgroups (p < 0.05). The 8-OHdG level of the two subgroups combined as one "asbestosis" group was significantly higher than that of the control group (control: 1.78, asbestosis: 2.39, p = 0.01). Further, 8-OHdG levels were moderately correlated with CEIs for all subjects (r = 0.35, p < 0.05) and with grades of asbestosis for all (r = 0.47, p < 0.01) and for male subjects (r = 0.43, p < 0.05). In multiple regression analyses, grade of asbestosis explained 27% of the total variation in 8-OHdG and was a better predictor than CEI or duration of exposure. Thus, the 8-OHdG level in leukocytic DNA is related to grade of asbestosis and to individual cumulative exposure and may serve as a biologic marker reflecting the status of oxidative DNA damage by asbestos.

Acetylcholinesterase Inhibition as an Indicator of Organophosphate and Carbamate Poisoning in Kenyan Agricultural Workers

Abstract: Acetylcholinesterase inhibition was determined for 666 Kenyan agricultural workers; 390 (586%) mainly pesticide applicators exposed to organophosphate and carbamate pesticides and 276 (414%) unexposed controls from four rural agricultural areas during 1993 and 1994 Baseline levels were depressed in the exposed group (61 ± 084; 409 ± 084) but not in the unexposed group (583 ± 091; 560 ± 087) Acetylcholinesterase inhibition was found in all exposed individuals and led, on average, to a decrease of baseline atetylcholinesterase levels of 33% (± 12%) The control groups had a nonsignificant decrease of only 4% (± 8%) The exposed subjects in Naivasha (flower growers) had the largest inhibition (36%), followed by Homabay (cotton growers) (35%) and Wundanyi (vegetable growers) (33%) Those in Migori (tobacco growers) had, by far, the least inhibition of acetylcholinesterase activity (26%), indicating inherent factors that led to less inhibition Acetylcholinesterase activity levels of 115 ex

Effects on Accidents of Time into Shift and of Short Breaks between Shifts.

Abstract: This study aimed to determine whether there was a peak in accidents in the second to fourth hours within a shift and to compare the effect on accidents of the presence or absence of a break of only eight hours between shifts in a shift cycle ("quick returns"). Archival accident records were obtained for a four-year period from two sister works within the same division of a heavy-industrial organization. The works had many similarities but differed in the shift systems used. One had "quick returns," whereas the other did not. Accident frequencies were analyzed across four variables, site, shift, time on shift, and process code (process code identified the process area in which the worker operated). These were analyzed by hierarchical log-linear analysis, using a significance level of 0.05. The results indicated there was a peak in accidents in the second and third hours into a shift, but provided only slight evidence for a detrimental effect of "quick returns."

Establishing Priorities for Occupational Health Research among Women Working in the Maquiladora Industry

Abstract: In order to estimate the prevalence of potentially hazardous exposures and the frequencies of, types of, and reasons for job transitions among women working in the Mexican maquiladora industry, an age- and occupation-stratified sample of 479 women, aged 16–40 years, living in 12 neighborhoods in Tijuana were interviewed. Considerable transition between industrial sectors was observed. About 20% had left their last job in a maquiladora because of hazardous or stressful working conditions and work-related health problems. Chemical exposures, ergonomic risks, noise, and stress were reported. The socio demographic characteristics and occupational risk profile of the maquiladora workforce, considered in the broader context of Mexico's development, indicate that occupational health research in the maquiladora should focus on musculoskeletal injuries, adverse reproductive outcomes, neurologic damage, and mental illness. Appropriate methods for investigating occupational risks in a highly mobile workforce...

The Natural Course of Musculoskeletal Symptoms and Clinical Findings in Upper Extremities of Female Milkers

Abstract: To explore milkers' state of health with regard to symptoms in the wrists and hands, a study of 80 female milkers was carried out 12 months after a Nordic questionnaire study of these subjects. Of these 80, 41 had reported pain and discomfort in the wrists and hands at the time of the questionnaire study, whereas the remaining 39 had had no such symptoms. To determine the sensitivity and specificity of the Nordic questionnaire, the follow-up study included examination by an unbiased clinician. The occurrence of symptoms in the wrists and hands during the preceding 12 months was found to have been rather stable-30 of the 41 milkers still reported pain, aching, and discomfort, and eight new cases were recorded. On clinical examination, symptoms including numbness, tingling, and coldness in the forearms and hands were reported by 51 of the 80 milkers, 14 of whom had clinical symptoms and signs indicating median nerve entrapment. Peritendinitis was diagnosed in four subjects and a ganglion cyst in one. The findings in the remaining group did not meet diagnostic criteria. All subjects with wrist and hand symptoms were still at work a year after the initial study. The sensitivity of the Nordic questionnaire when it came to identifying subjects with clinical findings was found to be unsatisfactory. The actual incidence of wrist and hand disorders may be underestimated if the Nordic questionnaire is used as the only instrument in epidemiologic screenings.

Hormonal Secretion of Nurses Engaged in Fast-rotating Shift Systems.

Abstract: The aim of the study was to assess whether fast-rotating shift systems, including one or two consecutive night shifts, would cause significant disturbances of the normal hormonal patterns of ten young female nurses working in an intensive care unit. Plasma cortisol, serum prolactin, and growth hormone were measured at the start, middle, and end of one morning (07-14), one afternoon (14-21), and two night shifts (21-07); urinary excretion rates of 6-sulfatoxymelatonin (aMT6s), adrenaline (epinephrine) and noradrenaline (norephinephrine) were determined for each half of the four shifts. During the night shifts, the hormones more sensitive to exogenous components, such as catecholamines, prolactin, and growth hormone, showed an immediate response to the shifted sleep/activity cycle, evidencing a "masking effect" due to the work activity. On the other hand, hormones having stronger endogenous components, such as cortisol and melatonin, showed a more stable pattern, with a slight tendency for partial adjustment of cortisol during the second night.

Tuberculosis Mortality and Silica Exposure: A Case—Control Study Based on a National Mortality Database for the Years 1983–1992

Abstract: A case-control study (8,740 cases; 83,338 controls) was done to evaluate the association between potential occupational exposure to silica and risk of tuberculosis (TB) mortality, using the National Occupational Mortality Surveillance database for 1983–1992. Potential silica exposure was based on the decedent's usual industry and occupation. Assignment of potential exposure to silica was based on the entire range of industries and occupations. Odds ratios (ORs) for mortality from respiratory TB associated with potential high and intermediate exposures to silica were 1.30 (95% CI 1.14–1.48) and 1.07 (95% CI 0.77–1.47), respectively, adjusting for silicosis, other pneumoconioses, age, gender, race, socioeconomic status, and potential exposure to active TB. The elevated OR was seen in all subgroups: male, female, white, and black. The average age at death/among respiratory TB cases with potential silica exposure was significantly younger by four years than that among cases without potential silica e...

Childhood Lead Poisoning in Russia: A Site-specific Pediatric Blood Lead Evaluation

Abstract: Lead poisoning in children is an international concern. Health effects vary according to a child's blood lead level. Historically, the problem of lead poisoning in Russia had been defined by analysis of hair samples. In Saratov, Russia, during the spring of 1996, the authors conducted the first evaluation of blood lead levels among Russian children. The mean blood lead level of 579 samples analyzed at the Centers for Disease Control and Prevention was 7.7 µg/dL (range 3.0 to 35.7 µg/dL). The sensitivity of hair analysis in identifying blood lead levels above 10 µg/dL was 50%. Most of the environmental samples evaluated (including water, dust, paint, and soil) were within acceptable U.S. remediation standards. Almost one-fourth of the Russian children evaluated during this site-specific investigation had blood lead levels capable of causing adverse health effects in children. Hair analysis is not an adequate method for identifying these children. Additional investigations in other Russian cities are necessary in order to determine the extent of lead poisoning in Russia's children.

Fatal Occupational Injuries in the Forestry and Logging Industry in North Carolina, 1977-1991.

Abstract: Fatal occupational injuries in the forestry and logging industry and occupation in the state of North Carolina from January 1, 1977, to December 31,1991, were analyzed. Data were obtained through t...

Evaluation of Interventions for Prevention of Back, Neck, and Shoulder Disorders in Three Occupational Groups

Abstract: An epidemiologic study was carried out in order to evaluate the effects of prevention programs at the workplace aimed at reducing back, neck, and shoulder morbidity among active workers. The intervention group included 275 workers in three occupational subgroups: hospital workers, warehouse workers, and office workers. The control group included 250 workers as comparable as possible to the intervention group. Comparisons were made, according to one-year changes in morbidity scores, for low back, upper back, neck, and shoulder disorders separately. An overall measure was also used. The one-year change in the overall measure was significantly different between the intervention group and the control group, indicating a positive effect of the prevention programs. Positive effects were stronger for some sites of pain and some occupational groups.

Occupational and Environmental Determinants for Benign Thyroid Disease and Follicular Thyroid Cancer

Abstract: Occupational and environmental determinants of benign thyroid disease and follicular thyroid cancer were evaluated in a series of cases in 1977–1987 Of the cases initially diagnosed as follicular thyroid cancer, only 31 remained after a reclassification, whereas 44 were found to be benign thyroid disease Both series were compared with 387 randomly selected population controls Occupational solvent exposure was strongly associated with benign thyroid disease (odds ratio, OR, 28; 95% confidence interval, 95% CI, 09–90 for women and OR 189; 95% CI 22–161 for men) Eight of the nine men found to have benign disease had been exposed to solvents, and six of them to trichloroethylene For both types of cases, a private well at the birth address increased the risk, OR 20; 95% CI 09–40 and OR 30; 95% CI 12–72, respectively, whereas the risk was lower for those living in coastal areas Less fish and shellfish in the diet increased the risk for malignant thyroid disease only Although based on s

Evaluation of Infant Diarrhea Associated with Elevated Levels of Sulfate in Drinking Water: A Case-Control Investigation in South Dakota

Abstract: The objective of this study was to assess the association between infant diarrhea and ingestion of water containing elevated sulfate levels. The authors identified 274 mothers of infants born in 19 South Dakota counties with high water sulfate concentrations. Demographic information and seven-day recall dietary and health data were obtained by telephone interviews. Sulfate in drinking water was measured from samples submitted by the participants. Logistic regression was used to estimate the risk for diarrhea (≥3 loose stools in 24 hours). Questionnaires were completed for 274 households: 69% drank municipal water and 54% reported using the water in the infants' diets. Thirty-nine infants developed diarrhea. Of the 170 households that submitted water samples, 141 (83%) were using the water in the infants' diets. The median sulfate level of the water samples was 264 mg/L. Twenty-five of the infants developed diarrhea. Average infant daily sulfate intake was not significantly associated with an incre...

Mortality among Welders Exposed to High and to Low Levels of Hexavalent Chromium and Followed for More Than 20 Years.

Abstract: Hexavalent chromium particles are generated in the welding of stainless steel. A cohort consisting of 233 welders working on stainless steel and exposed to high levels of chromium was selected. According to an earlier survey, the hexavalent chromium exposures of such welders are often above 20 μg/m3 Another cohort consisting of 208 railway track welders exposed to low levels of chromium was also selected. The participants of both cohorts had welded for at least five years between 1950 and 1965 and were followed for mortality until December 1992. Among the welders exposed to high levels of chromium, six deaths due to pulmonary tumors occurred. This number is higher than the two deaths that occurred among the welders exposed to low levels of chromium and the corresponding mortality of the general population, but not significantly higher. Thus, exposure to stainless steel welding fumes might increase the incidence of pulmonary tumors.

Semen Quality of Workers Exposed to Ionizing Radiation in Decontamination Work after the Chernobyl Nuclear Reactor Accident

Abstract: The objective of the study was to assess effects of radiation on sperm quality, including ultramorphology of spermatozoa of men who worked as salvage workers at the Chernobyl nuclear reactor accident site or in the adjacent region. Semen characteristics were assessed by light microscopy, biochemical analysis, and quantitative ultramorphologic analysis seven years after the accident. Samples were collected in the Ukraine, examined there by routine semen analysis, fixed, and transferred to Israel for further examinations. The study population consisted of 18 radiation-exposed individuals. Eighteen unexposed Ukrainian men were examined as controls. Sperm motility was found to be reduced in the radiation-exposed workers. Ultramorphologic defects were evident in the sperm nucleus. Fertility potential, was adversely affected among the exposed workers. Thus, salvage workers who had worked at the Chernobyl nuclear reactor accident site or in the vicinity thereof were found to manifest ultramorphologic abn...

Job Strain in Shift and Daytime Workers.

Abstract: Cross-sectional questionnaire data were used to compare the levels of job strain in shift and daytime workers. Job strain was measured according to Karasek's Demands/Discretion model. Four occupational groups were included: drivers, industrial workers, policemen/watchmen, and cooks. The study subjects were a random sample of 508 daytime workers and 418 shift workers. Job demand did not differentiate between shift and daytime workers, comparing groups broken down by gender and by occupation. The daytime workers reported higher levels of job strain than the shift workers, and women experienced a higher level of job strain than did men. Multiple linear regression analysis showed that only occupational group and gender predicted job strain level. Shiftwork was not significantly associated with job strain in the regression model.

Shiftwork Advantages as Predictors of Health.

Abstract: This study investigated the relationships between shiftwork advantages and subjective health. The Standard Shiftwork Index and a measure of shiftwork advantages were completed by 175 shift workers. Four advantage subscales were developed, corresponding to family, social/domestic, work, and time for oneself. Family advantages were negatively associated with psychological distress, cognitive and somatic anxiety, chronic fatigue, and digestive and cardiovascular symptoms (p < 0.05). After family advantages were partialled out, social/domestic advantages were negatively related to psychological distress (p < 0.05). Variety in work on each shift was significantly related to psychological distress and digestive symptoms. After the effects of shift and personality characteristics were accounted for, family advantages predicted a significant amount of the variance of cognitive anxiety (p < 0.05) and chronic fatigue (p < 0.01), and variety in work, family, and social/domestic advantages predicted a significant amount of variance of psychological distress (p < 0.05). The authors conclude that family advantages are related to psychological health, and to a lesser extent physical health, but that other advantages have little relationship to subjective health.