Job strain, worksite support, and nutrient intake among employed Japanese men and women

BACKGROUND: The association of job strain (as defined by the job demands/control model) and worksite support with nutrient intake is not clear. METHODS: A questionnaire survey was conducted of 25,104 workers employed in nine companies in Japan. Job strain and worksite support were assessed using the Job Content Questionnaire. Daily intake of 17 nutrients was measured using a dietary history questionnaire. Data from 15,295 men and 2,853 women were analyzed, controlling for age, education, marital status, occupation, and study site. RESULTS: Among men, job strain was positively associated with average daily intakes of fat, vitamin E, cholesterol, poly- and mono-unsaturated fatty acids (p for trend<0.05), and worksite support was positively associated with average daily intakes of total energy, crude fiber, retinol, carotene, vitamins A, C, and E, cholesterol, and saturated fatty acid (p for trend<0.05). Among women, worksite support was positively associated with average daily intakes of total energy, protein, vitamin E, and polyunsaturated fatty acid (p for trend<0.05). However these differences were generally small. CONCLUSIONS: The present study showed that job strain and worksite support were only weakly and inconsistently associated with nutritional intakes. It does not seem that changes in nutritional intakes explain the association between job strain or worksite support and coronary heart disease.     

Psychosocial work environment and mental health--a meta-analytic review

OBJECTIVES: To clarify the associations between psychosocial work stressors and mental ill health, a meta-analysis of psychosocial work stressors and common mental disorders was undertaken using longitudinal studies identified through a systematic literature review. METHODS: The review used a standardized search strategy and strict inclusion and quality criteria in seven databases in 1994-2005. Papers were identified from 24,939 citations covering social determinants of health, 50 relevant papers were identified, 38 fulfilled inclusion criteria, and 11 were suitable for a meta-analysis. The Comprehensive Meta-analysis Programme was used for decision authority, decision latitude, psychological demands, and work social support, components of the job-strain and iso-strain models, and the combination of effort and reward that makes up the effort-reward imbalance model and job insecurity. Cochran's Q statistic assessed the heterogeneity of the results, and the I2 statistic determined any inconsistency between studies. RESULTS: Job strain, low decision latitude, low social support, high psychological demands, effort-reward imbalance, and high job insecurity predicted common mental disorders despite the heterogeneity for psychological demands and social support among men. The strongest effects were found for job strain and effort-reward imbalance. CONCLUSIONS: This meta-analysis provides robust consistent evidence that (combinations of) high demands and low decision latitude and (combinations of) high efforts and low rewards are prospective risk factors for common mental disorders and suggests that the psychosocial work environment is important for mental health. The associations are not merely explained by response bias. The impact of work stressors on common mental disorders differs for women and men.     

Lower socioeconomic status among men in relation to the association between job strain and blood pressure

OBJECTIVES: This study attempted to determine whether the association between job strain (high job demands plus low job control) and blood pressure among men varies by socioeconomic status. METHODS: The cross-sectional associations between job strain and ambulatory blood pressure, by level of education, occupational status, and income, and the interaction between job strain and these measures of socioeconomic status were assessed by multiple linear regression, adjusted for age, race or ethnicity, body mass index, alcohol use, smoking, standing position, and worksite for 283 men, aged 30-60 years, from eight worksites in New York City. RESULTS: A substantial association between job strain and work ambulatory blood pressure was found among men with lower socioeconomic status, ranging from 2.7-11.8 mm Hg systolic to 1.9-6.1 mm Hg diastolic blood pressure, depending upon the measure of socioeconomic status examined. However, in the groups with high socioeconomic status, the association between job strain and ambulatory blood pressure at work was much smaller, the range in blood pressure being 0-5.3 (systolic) and 0.2-2.1 (diastolic) mm Hg. Two of the 10 tests of the interaction between job strain and socioeconomic status had a P-value of <0.05. CONCLUSIONS: These data provide evidence that the relationship between job strain and blood pressure is greater among men with lower socioeconomic status.     

Job insecurity and its association with health among employees in the Taiwanese general population

As employers respond to intensive global competition through the deregulation of labor, job insecurity has become a widespread problem. It has been shown to have significant health impacts in a growing number of workers, but less is known about its social distribution, the mechanisms through which it may act, and the moderating effects of gender, socioeconomic position, and company size. Utilizing data from a national survey of a representative sample of paid employees in Taiwan, we examined the prevalence of job insecurity and its associations with psychosocial work characteristics and health status. A total of 8705 men and 5986 women aged between 25 and 65 years old were studied. Information on perceived job insecurity, industrial and occupational types, psychosocial work characteristics as assessed by the Job Strain model, and various measures of health status were obtained by a self-administered questionnaire. The overall prevalence of job insecurity was high (50%). Job insecurity was more prevalent among employees with lower education attainment, in blue-collar and construction workers, those employed in smaller companies, and in older women. Insecure employees also reported lower job control, higher job demands, and poor workplace social support, as compared with those who held secure positions. Regression analyses showed that job insecurity was strongly associated with poor health, even with adjustment of age, job control, job demands, and work place social support. The deleterious effects of job insecurity appeared to be stronger in men than women, in women who held managerial or professional jobs than women in other employment grades, and in those working in larger companies than smaller ones. The findings of this study suggest that perceived job insecurity is an important source of stress, and it is accompanied with adverse psychosocial work conditions and poor health. High-risk groups were identified for further investigation.     

Job strain, social support at work, and incidence of myocardial infarction

OBJECTIVES: The combination of high psychological job demands and low decision latitude (high job strain) has been associated with an increased risk of coronary heart disease. It has been proposed that this may also be the case for low social support at work. The aim of this study was to analyse the relations between these psychosocial factors and incidence of myocardial infarction. METHODS: Associations between psychosocial work characteristics and incidence of myocardial infarction was investigated through a population based case-control study. The study base comprised employed men and women in five Swedish counties during the years 1976-84. Cases of first myocardial infarction were identified from hospital discharge registers and death records from outside hospital, controls were selected through a random sample, and psychosocial work environment was assessed through a job exposure matrix on the basis of the occupation in the 1970 and 1975 censuses. RESULTS: An increased incidence of myocardial infarction was found for men and women in occupations characterised by low decision latitude. For men this increase was seen primarily in combination with high psychological demands (high job strain) and low social support at work. Younger men (30-54 years of age) in occupations with both high job strain and low social support at work had a relative risk of 1.79 (95% confidence interval (95% CI) 1.22 to 2.65) compared with subjects in low strain and high social support jobs after controlling for age, county of residence, and socioeconomic group. CONCLUSIONS: Our results indicate that jobs characterised by low decision latitude, high job strain, or low social support at work may be associated with an increased risk of acute myocardial infarction. If these associations are causal they may be of substantial importance from the point of view of workers' health.

 

     

Psychosocial work environment and depression: epidemiologic assessment of the demand-control model

OBJECTIVES: This study examined the relation between occupational variables and 3 forms of depression (major depressive episode, depressive syndrome, and dysphoria). It was hypothesized that individuals working in occupations with high psychologic strain (high psychologic demands and low decision authority) would have a higher prevalence of depression relative to those working in occupations with the other 3 possible conditions. METHODS: The analysis was based on data for 905 respondents who were employed full-time in the year before the follow-up interview for the Epidemiologic Catchment Area Program in Baltimore, Md, between 1993 and 1996. Psychosocial work environment, sociodemographic variables, and psychopathology were assessed in a household interview that included the National Institute of Mental Health Diagnostic Interview Schedule. Subscales for the demand-control model for psychosocial work environment were modified slightly after factor analysis. RESULTS: High job strain was associated with greater prevalence of all 3 forms of depression, especially major depressive episode. The results were stronger for women; for men, being unmarried was the strongest prevalence correlate. CONCLUSIONS: Major depressive episode, depressive syndrome, and dysphoria are strongly associated with the psychosocial dimensions of the demand-control model.     

Epidemiology of job stress and health in Japan: review of current evidence and future direction.

With the increasing concern about job stress, there is a growing body of literature addressing psychosocial job stress and its adverse effects on health in Japan. This paper reviews research findings over the past 15 years concerning the assessment of job stress, the relationship of job stress to mental and physical health, and the effects of worksite stress reduction activities in Japan. Although studies were conducted in the past using ad-hoc job stress questionnaires, well-established job stressor scales have since been translated into Japanese, their psychometric properties tested and these scales extensively used in recent epidemiologic studies. While the impact of overtime and quantitative job overload on mental health seems moderate, job control, skill use and worksite support, as well as qualitative job demands, had greater effects on psychological distress and drinking problems in cross-sectional and prospective studies. These job stressors also indicated a strong association with psychiatric disorders, including major depression, even with a prospective study design. Long working hours were associated with a higher risk of myocardial infarction, diabetes mellitus and hypertension. There is evidence that the job demands-control model, as well as the use of new technology at work, is associated with higher levels of blood pressure and serum lipids among Japanese working populations. Fibrinolytic activity, blood glucose levels, immune functions and medical consultation rates were also affected by job stressors. It is further suggested that Japanese workers tend to suppress expression of positive feelings, which results in apparently higher psychological distress and lower job satisfaction among Japanese workers compared with workers in the U.S. Future epidemiologic studies in Japan should focus more on a prospective study design, theoretical models of job stress, job stress among women, and cultural difference and well-designed intervention studies of various types of worksite stress reduction.     

Psychosocial working conditions and psychological well-being among employees in 34 European countries

Purpose

The aim of this study was to explore the associations between psychosocial working conditions and psychological well-being among employees in 34 European countries. Another objective was to examine whether these associations varied according to occupation and country.

Methods

The study was based on data from the European Working Conditions Survey 2010 including 33,443 employees, 16,512 men and 16,931 women, from 34 European countries. Well-being was measured by the WHO-5 well-being index. Twenty-five psychosocial work factors were constructed including job demands, role stressors, work hours, job influence and freedom, job promotion, job insecurity, social support, quality of leadership, discrimination and violence at work, and work-life imbalance. The associations between these factors and well-being were examined using multilevel logistic regression analyses. Different models were performed including interaction tests.

Results

When all 25 psychosocial work factors were studied simultaneously in the same model with adjustment variables, 13 showed a significant association with poor well-being among both genders: quantitative demands, demands for hiding emotions, low possibilities for development, low meaning of work, low role conflict, low quality of leadership, low social support, low sense of community, job insecurity, low job promotion, work-life imbalance, discrimination, and bullying. The association with low sense of community on poor well-being was particularly strong.

Conclusions

A large number of psychosocial work factors were associated with poor well-being. Almost no country and occupational differences were found in these associations. This study gave a first European overview and could be useful to inform cross-national policy debate.     

Job strain and ambulatory blood pressure profiles.

Occupational characteristics were used to study the role of job stress in the pathogenesis of hypertension. Ambulatory 24-h recordings of blood pressure were made for 161 men with borderline hypertension. From the occupational classification system scores for psychological demands, control, support, physical demands, and occupational hazards were obtained. The results indicated that the ratio between psychological demands and control (strain) was significantly associated with diastolic (but not systolic) blood pressure at night and during work. The association between job strain and diastolic blood pressure at night and during work was greatly strengthened when the subjects with occupations classified as physically demanding were excluded from the analysis. The conclusion was reached that a measure of job strain derived from the occupational classification is useful in predicting variations in diastolic blood pressure levels during sleep and work for men with borderline hypertension.     

Use of benzodiazepine drugs and perceived job stress in a cohort of working men and women in Belgium. Results from the BELSTRESS-study

The aim of the Belstress Study was to see whether use of benzodiazepines is associated with perceived job stress as measured by Karasek's job-strain model. This model has as its central tenet that the most adverse health outcomes are to be expected in high strain jobs characterized by high job demands and low job control. An extension of the model states that the most noxious combination is high job demands, low control and low social support at work. Sample subjects were recruited from 25 Belgian companies between 1994 and 1998, and cover a wide range of occupations. A 5.6% of 16,094 men and 9.3% of 5012 women aged 35-59 years report use of benzodiazepines during the last month. A clear association is displayed between self-reported use of benzodiazepines and a high strain job compared to a low strain job (men: OR=1.93, 99% CI=1.4-2.6; women: OR=1.66, 99% CI=1.0-2.7), after adjustment is made for socio-demographic confounders (age, level of education, occupational group, employment sector, living situation). The independent association with quartile level of job demands is a striking feature (men: OR of highest quartile compared to lowest quartile group=1.91, 99% CI=1.4-2.6; women: OR=1.99, 99% CI=1.3-3.1). In men, an inverse association with quartile level of job control is observed (OR= 0.65, 99% CI=0.5-0.9) whereas in women a clear tendency in that direction is displayed (OR=0.62, 99% CI=0.4-1.1). The association with low social support is less clear; an independent association between use of benzodiazepines and iso-strain was observed particularly in men.     

Association between job strain and prevalence of hypertension: a cross sectional analysis in a Japanese working population with a wide range of occupations: the Jichi Medical School cohort study

OBJECTIVES—To explore the association between the prevalence of hypertension in a Japanese working population and job strain (a combination of low control over work and high psychological demands), and to estimate this association in different sociodemographic strata.METHODS—From a multicentre community based cohort study of Japanese people, sex specific cross sectional analyses were performed on 3187 men and 3400 women under 65 years of age, all of whom were actively engaged in various occupations throughout Japan. The baseline period was 1992-4. The association between job characteristics—measured with a Japanese version of the Karasek demand-control questionnaire—and the prevalence of hypertension defined by blood pressure and from clinical diagnoses were examined. Adjustments were made for possible confounders. The analyses were repeated for stratified categories of occupational class, educational attainment, and age group.RESULTS—In men, the level of job strain (the ratio of psychological job demands to job control) correlated with the prevalence of hypertension. In a multiple logistic regression model, job strain was significantly related to hypertension (odds ratio 1.18; 95% confidence interval 1.05 to 1.32), after adjustment for age, employment (white collar v blue collar), marital status, family history of hypertension, cigarette smoking, alcohol intake, physical activity, and body mass index. The stratified analyses showed significant excess risks in the subordinate groups compared with managers, blue collar workers, less educated workers, and the older age groups. This association was not significant in women. Multiple linear regression analyses, with systolic and diastolic blood pressures as dependent variables, did not show any significant association.CONCLUSIONS—The findings provided limited proof that job strain is related to hypertension in Japanese working men. Older men in a lower social class may be more vulnerable to the hypertensive effects of job strain.     

Socioeconomic inequalities in health in the working population: the contribution of working conditions

BACKGROUND: The aim was to study the impact of different categories of working conditions on the association between occupational class and self-reported health in the working population. METHODS: Data were collected through a postal survey conducted in 1991 among inhabitants of 18 municipalities in the southeastern Netherlands. Data concerned 4521 working men and 2411 working women and included current occupational class (seven classes), working conditions (physical working conditions, job control, job demands, social support at work), perceived general health (very good or good versus less than good) and demographic confounders. Data were analysed with logistic regression techniques. RESULTS: For both men and women we observed a higher odds ratio for a less than good perceived general health in the lower occupational classes (adjusted for confounders). The odds of a less than good perceived general health was larger among people reporting more hazardous physical working conditions, lower job control, lower social support at work and among those in the highest category of job demands. Results were similar for men and women. Men and women in the lower occupational classes reported more hazardous physical working conditions and lower job control as compared to those in higher occupational classes. High job demands were more often reported in the higher occupational classes, while social support at work was not clearly related to occupational class. When physical working conditions and job control were added simultaneously to a model with occupational class and confounders, the odds ratios for occupational classes were reduced substantially. For men, the per cent change in the odds ratios for the occupational classes ranged between 35% and 83%, and for women between 35% and 46%. CONCLUSIONS: A substantial part of the association between occupational class and a less than good perceived general health in the working population could be attributed to a differential distribution of hazardous physical working conditions and a low job control across occupational classes. This suggests that interventions aimed at improving these working conditions might result in a reduction of socioeconomic inequalities in health in the working population.     

Occupational strain and the incidence of coronary heart disease

The hypothesis that men in high "strain" occupations have an increased risk of developing coronary heart disease was tested during an 18-year follow-up study from 1965-1983 of a cohort of 8,006 men of Japanese ancestry in Hawaii. There were no significant associations between the incidence of coronary heart disease and the individual job components of high psychologic demands and low job control or for the high strain interaction of these two characteristics. There were, in fact, trends of associations opposite to that predicted by the job strain model which were of borderline significance in multivariate analyses. Stratified analyses by level of acculturation showed similar inverse associations of job strain and coronary heart disease for the more Westernized men and no association for the more traditional men. There were also no significant associations among the various job characteristics and the major risk factors for coronary heart disease in this cohort. The disagreement of these results with those from other studies may be due to methodologic differences of using men whose usual and current occupations were the same in this study compared with using only current occupation in the other studies, the use of different methods of measuring job strain, or the possibility that men in this cohort perceive or react to occupational strain differently.     

Occupational Class Differences in Body Mass Index and Weight Gain in Japan and Finland

Background

Occupational class differences in body mass index (BMI) have been systematically reported in developed countries, but the studies have mainly focused on white populations consuming a Westernized diet. We compared occupational class differences in BMI and BMI change in Japan and Finland.

Methods

The baseline surveys were conducted during 1998–1999 among Japanese (n = 4080) and during 2000–2002 among Finnish (n = 8685) public-sector employees. Follow-up surveys were conducted among those still employed, in 2003 (n = 3213) and 2007 (n = 7086), respectively. Occupational class and various explanatory factors were surveyed in the baseline questionnaires. Linear regression models were used for data analysis.

Results

BMI was higher at baseline and BMI gain was more rapid in Finland than in Japan. In Finland, baseline BMI was lowest among men and women in the highest occupational class and progressively increased to the lowest occupational class; no gradient was found in Japan (country interaction effect, P = 0.020 for men and P < 0.0001 for women). Adjustment for confounding factors reflecting work conditions and health behavior increased the occupational class gradient among Finnish men and women, whereas factors related to social life had no effect. No statistically significant difference in BMI gain was found between occupational classes.

Conclusions

The occupational class gradient in BMI was strong among Finnish employees but absent among Japanese employees. This suggests that occupational class inequalities in obesity are not inevitable, even in high-income societies.Key words: occupational class, body mass index, weight gain, international comparisons     

Gender and Work Stress: Differential Exposure and Vulnerability

Three work conditions have evidenced consistent relationships to health-related outcomes: control, demands, and job complexity. Most studies of work stress involve samples of male workers. The hypothesis of differential vulnerability contends that women would be more responsive than men to work stressors. The differential exposure hypothesis proposes that there is no gender difference in the effects of work stressors, but patterns of occupational segregation increase women's exposure to detrimental job conditions. Previous studies of gender differences in responses to work stress are equivocal, indicating both similarity and highly specific differences. This study explores gender differences in the effects of work conditions on psychological distress and self-medication. Job satisfaction and perceived job stress are specified as mediating variables. The results do not support the hypothesis of general differential vulnerability. The only gender difference observed indicates that women are less responsive than men to job demands.     

Work and health in a contemporary society: demands, control, and insecurity

OBJECTIVE: To examine independent associations of job strain (high demands and low control) and job insecurity with mental and physical health outcomes. DESIGN: Cross sectional general population study conducted in 2000 using a self completed questionnaire. SETTING: Two adjoining cities in south east Australia. SUBJECTS: 1188 employed professionals, aged 40-44 years, 55% (n = 655) male. MAIN OUTCOME MEASURES: Depression, anxiety, physical, and self rated health (SRH). RESULTS: Adverse job conditions were relatively prevalent as 23% of the sample reported high job strain, while 7.3% and 23% reported high and moderate job insecurity respectively. Associations between job conditions and health persisted after adjustment for gender, education, marital status, employment status, major life events, and negative affectivity (personality). When adjusted for job strain, high job insecurity was independently associated with a greater than threefold increase in odds for poor SRH, depression and anxiety (OR (95% confidence intervals) poor SRH: 3.72 (1.97 to 7.04) depression: 3.49 (1.90 to 6.41), anxiety: 3.29 (1.71 to 6.33)), and a twofold increase for physical health 2.19 (1.21 to 3.95). High job strain also showed significant independent associations with depression: 2.54 (1.34 to.4.75) and anxiety: 3.15 (1.48 to 6.70). CONCLUSION: In this relatively privileged socioeconomic group, insecure employment and high job strain showed independent, consistent, and strong associations with physical and mental health. These adverse job conditions are on the increase, particularly insecure employment, and the influence of these two work conditions are an important focus for future public health research and their prevalence and impact should be examined in other occupations.     

Job strain and prevalence of hypertension in a biracial population of urban bus drivers.

OBJECTIVES. In this study we tested the association between occupational stress--as measured by job demands, decision latitude, and job strain--and hypertension in a population of 1396 Black and White bus drivers. METHODS. Height, weight, blood pressure, and medical history were assessed by physical exam. Drivers completed a questionnaire assessing their work schedules, personal habits, and self-perceptions about job demands and decision latitude. RESULTS. Univariate analyses revealed significant inverse associations; lower levels of job demands and job strain were associated with a higher prevalence of hypertension for Blacks and Whites. After 12 confounding variables were controlled for, the association between these two measures of occupational stress and hypertension became nonsignificant. Decision latitude was also not significantly associated with hypertension. CONCLUSIONS. Our findings are inconsistent with previous studies' findings of a positive association between job strain and chronic diseases. The difference in results may be explained by our incorporation of individuals' perceptions in the measurement of occupational stressors and our use of individuals from a single occupation with comparable job responsibilities and income, thus controlling for potential confounding by social class.     

Differences in the association between psychosocial work conditions and physical work load in female- and male-dominated occupations. MUSIC-Norrt?lje Study Group.

This study investigated whether there is a relationship between high physical work load and adverse psychosocial work factors, and whether this relationship is different for women and men. Separate analyses for female registered nurses and assistant nurses were made because these are common occupations involving high physical and psychological demands. This study was part of the MUSIC-Norrt?lje study, a population study with the overall aim of identifying risk factors for musculoskeletal disorders. The respondents, 1423 gainfully employed men and women, were randomly selected from the study population. The exposure assessments referred to a typical workday during the previous 12 months. Physical exposure was investigated by interview, psychosocial work factors by interview and questionnaire. For the women, but not the men, mainly routine work and a job strain situation, according to the model of Karasek and Theorell, increased the probability of having a high physical work load, assessed as a time-weighted average of energy expenditure in multiples of the resting metabolic rate. Results indicated that in female-dominated occupations, high physical work load might also imply adverse psychosocial conditions. A higher frequency of high physical work load and job strain was observed among assistant nurses compared with registered nurses. Covariance between physical and psychosocial demands makes it difficult to determine the relative influence of each in health problems. Results of the present study imply that this is a larger problem in studies of women than men.     

Impact of occupational stress on stroke across occupational classes and genders

The aims of the present study were to analyze the association between incident stroke, occupational class and stress and to examine whether the association is found in both men and women in a prospective study of Japanese male and female workers. A total of 3190 male and 3363 female Japanese community-dwelling workers aged 65 or under with no history of cardiovascular disease were followed. Occupational stress was evaluated using a demand-control questionnaire. The impact on stroke was examined in stratified analyses of occupational classes. We identified 147 incident strokes (91 in men and 56 in women) during the 11-year follow-up period. Men with high strain jobs (combination of high job demand and low job control) were nearly three times more likely to suffer from a stroke than men with low strain jobs (combination of low job demand and high job control). Among male workers in low occupational classes (blue-collar and non-managerial work), job strain was associated with a higher risk of stroke. In contrast, there was no association between job strain and incident stroke among male workers in high occupational classes (white-collar and managerial work). No statistically significant differences were found for stroke incidence among the job characteristic categories in all the female participants. However, significant, over five-fold excess risks were found among white-collar and managerial female workers exposed to high job strain, compared with their counterparts with low strain jobs. Our study of Japanese workers provided supportive evidence for vulnerability to occupational stress among lower occupational class workers in males but not in females.     

Sinonasal cancer and occupation. Results from the reanalysis of twelve case-control studies

A pooled reanalysis of twelve case-control studies on sinonasal cancer and occupation from seven countries was conducted in order to study associations with occupations other than wood- and leather-related occupations. The pooled data set included a total of 930 cases (680 men and 250 women) and 3,136 controls (2,349 men and 787 women). All the studies included a detailed occupational history for cases and controls. Each job was coded using the same classifications for occupation and industry. Two approaches were used in the analysis: systematic analysis of occupations; a priori analysis using a preestablished list of occupations and industries. The results confirmed associations observed in several studies not included in this analysis. For agricultural workers, significant excesses were observed for squamous cell carcinoma among women (OR = 1.69) and men (OR = 3.72 for ten years or more of employment as an orchard worker), and adenocarcinomas among men (OR = 2.98 for ten years or more of employment). Associations with textile occupations were observed for adenocarcinoma among women (OR = 2.60) and squamous cell carcinoma among men (OR = 5.09 for fiber preparers, 3.01 for bleachers). Elevated risks for both histologic types were observed among men employed in food manufacturing (OR = 3.25, adenocarcinoma), or as food preservers (OR = 13.9, squamous cell carcinoma), and among men employed as cooks (OR = 1.99, squamous cell carcinoma). A positive association with squamous cell carcinoma was observed for male transport equipment operators (OR = 1.21), and also with adenocarcinoma for male motor-vehicle drivers (OR = 2.50). A number of other associations were observed in the systematic analysis. Am. J. Ind. Med. 31:153–165, 1997. © 1997, Wiley-Liss Inc.