Journal of Occupational Medicine and Toxicology - Latest articles

Effort-reward imbalance and overcommitment in employees in a Norwegian municipality: a cross sectional study

Bjorn Lau — 2008-04-30

Background: The aim of this study was to validate a Norwegian version of the Effort-Reward Imbalance Questionnaire (ERI-Q). Methods: One thousand eight-hundred and three employees in a medium-sized Norwegian municipality replied to the ERI-Q, and health-related variables such as self-reported general health, psychological distress, musculoskeletal complaints, and work-related burnout were examined. Results: Sound psychometric properties were found for this Norwegian version of the ERI-Q. When the two dimensions of ERI and overcommitment were analyzed in four types of employees, the results showed that employees characterized by a combination of high values on ERI and overcommitment had more unfavorable health scores than others. Employees with low effort-reward and overcommitment scores had more favorable health scores. Employees with scores on the overcommitment and the effort-reward scales that are supposed to have opposite effects on health (that is, the combination of low overcommitment with a high effort-reward score and vice versa), had health scores somewhere in between the two other groups. Conclusions: Satisfactory psychometric properties were found for most of the latent factors in the ERI-Q. The findings also indicate that it may be fruitful to explore health conditions among employees with different combinations of effort-reward and overcommitment.

Self-reported work ability of Norwegian women in relation to physical and mental health, and to the work environment

2008-04-22

ObjectivesTo examine the self-reported level of work ability among female employees and the relationship between work ability and demographic characteristics, physical health, mental health, and various psychosocial and organizational work environment factors. Methods: Participants were 597 female employees with an average age of 43 years from urban and rural areas in Norway. Trained personnel performed a structured interview to measure demographic variables, physical health, and characteristics of the working environment. Mental health was assessed using the 25-item version of the Hopkins Symptoms Checklist (HSCL-25). Work ability was assessed using a question from the Graded Reduced Work Ability Scale. Results: Of the 597 female employees, 8.9% reported an extremely or very reduced ability to work. Twenty-four percent reported poor physical health and 21.9% reported mental distress (≥ 1.55 HSCL-25 cut-off). Women, who reported moderately and severely reduced work ability, did not differ a lot. Moderately reduced work ability increased with age and was associated with physical and mental health. Severely reduced work ability was strongly associated only with physical health and with unskilled occupation. Of eight work environment variables, only three yielded significant associations with work ability, and these associations disappeared after adjustment in the multivariate analysis. Conclusion: Results indicate that ageing, in addition to poor self-reported physical health and unskilled work, were the strongest factors associated with reduced work ability among female employees. Impact of work environment in general was visible only in univariate analysis.

The effects of a graduated aerobic exercise programme on cardiovascular disease risk factors in the NHS workplace: a randomised controlled trial

2008-02-28

Background: Sufficient levels of physical activity provide cardio-protective benefit. However within developed society sedentary work and inflexible working hours promotes physical inactivity. Consequently to ensure a healthy workforce there is a requirement for exercise strategies adaptable to occupational time constraint. This study examined the effect of a 12 week aerobic exercise training intervention programme implemented during working hours on the cardiovascular profile of a sedentary hospital workforce. Methods: Twenty healthy, sedentary full-time staff members of the North West London Hospital Trust cytology unit were randomly assigned to an exercise (n = 12; mean ± SD age 41 ± 8 years, body mass 69 ± 12 kg) or control (n = 8; mean ± SD age 42 ± 8 years, body mass 69 ± 12 kg) group. The exercise group was prescribed a progressive aerobic exercise-training programme to be performed 4 times a week for 8 weeks (initial intensity 65% peak oxygen consumption (VO2 peak)) and to be conducted without further advice for another 4 weeks. The control was instructed to maintain their current physical activity level. Oxygen economy at 2 minutes (2minVO2), 4 minutes (4minVO2), VO2 peak, systolic blood pressure (SBP), diastolic blood pressure (DBP), BMI, C-reactive protein (CRP), fasting glucose (GLU) and total cholesterol (TC) were determined in both groups pre-intervention and at 4 week intervals. Both groups completed a weekly Leisure Time Questionnaire to quantify additional exercise load. Results: The exercise group demonstrated an increase from baseline for VO2 peak at week 4 (5.8 ± 6.3 %) and 8 (5.0 ± 8.7 %) (P < 0.05). 2minVO2 was reduced from baseline at week 4 (-10.2 ± 10.3 %), 8 (-16.8 ± 10.6 %) and 12 (-15.1 ± 8.7 %), and 4minVO2 at week 8 (-10.7 ± 7.9 %) and 12 (-6.8 ± 9.2) (P < 0.05). There was also a reduction from baseline in CRP at week 4 (-0.4 ± 0.6 mg·L-1) and 8 (-0.9 ± 0.8 mg·L-1) (P < 0.05). The control group showed no such improvements. Conclusion: This is the first objectively monitored RCT to show that moderate exercise can be successfully incorporated into working hours, to significantly improve physical capacity and cardiovascular health.

A prospective study of decline in lung function in relation to welding emissions

Sigve W Christensen, Jens Peter Bonde and Øyvind Omland — 2008-02-26

Background: Numerous cross-sectional studies have reported reduced lung function among welders but limitations of exposure assessment and design preclude causal inference. The aim of this study was to investigate if long-term exposure to welding fume particulates accelerates the age-related decline in lung function. Methods: Lung function was measured by spirometry in 1987 and 2004 among 68 steel welders and 32 non-welding production workers. The decline in forced expiratory volume (FEV1) was analysed in relation to cumulated exposure to fume particulates among welders during the follow-up period. Results: Among smokers the decline in FEV1 through follow-up period was in average 150 ml larger among welders than non-welders while the difference was negligible among non-smokers. The results did not reach statistical significance and within welders the decline in lung function was not related to the cumulated welding particulate exposure during follow-up period Conclusion: Long-term exposure to welding emissions may accelerate the age-related decline of lung function but at exposure levels in the range of 1.5 to 6.5 mg/m3 the average annual excess loss of FEV1 is unlikely to exceed 25 ml in smokers and 10 ml in non-smokers.

Effect of montelukast on platelet activating factor- and tachykinin induced mucus secretion in the rat

Rene Schmidt, Petra Staats, David A Groneberg and Ulrich Wagner — 2008-02-20

Background: Platelet activating factor and tachykinins (substance P, neurokinin A, neurokinin B) are important mediators contributing to increased airway secretion in the context of different types of respiratory diseases including acute and chronic asthma. Leukotriene receptor antagonists are recommended as add-on therapy for this disease. The cys-leukotriene-1 receptor antagonist montelukast has been used in clinical asthma therapy during the last years. Besides its inhibitory action on bronchoconstriction, only little is known about its effects on airway secretions. Therefore, the aim of this study was to evaluate the effects of montelukast on platelet activating factor- and tachykinin induced tracheal secretory activity. Methods: The effects of montelukast on platelet activating factor- and tachykinin induced tracheal secretory activity in the rat were assessed by quantification of secreted 35SO4 labelled mucus macromolecules using the modified Ussing chamber technique. Results: Platelet activating factor potently stimulated airway secretion, which was completely inhibited by the platelet activating factor receptor antagonist WEB 2086 and montelukast. In contrast, montelukast had no effect on tachykinin induced tracheal secretory activity. Conclusion: Cys-leukotriene-1 receptor antagonism by montelukast reverses the secretagogue properties of platelet activating factor to the same degree as the specific platelet activating factor antagonist WEB 2086 but has no influence on treacheal secretion elicited by tachykinins. These results suggest a role of montelukast in the signal transduction pathway of platelet activating factor induced secretory activity of the airways and may further explain the beneficial properties of cys-leukotriene-1 receptor antagonists.

Sweat rate and sodium loss during work in the heat

Graham P Bates and Veronica S Miller — 2008-01-29

ObjectiveSignificant and poorly documented electrolyte losses result from prolonged sweating. This study aimed to quantify likely sodium losses during work in heat. Methods: Male subjects exercised in an environmental chamber on two consecutive days in both winter and summer. Sweat collecting devices were attached to the upper arms and legs. Results: Sweat rates were higher and sodium concentrations were lower in the summer (acclimatised) than the winter (unacclimatised) trials. Sweat sodium concentration was reduced on the second day in summer but not winter. Regional differences were found in both seasons. Conclusion: The difference between days in summer probably reflects short-term acclimation. The difference between seasons reflects acclimatisation. The data predict average sodium (Na) losses over a work shift of 4.8–6 g, equivalent to 10–15 g salt (NaCl). Losses are potentially greater in unacclimatised individuals.Fluid and electrolyte losses resulting from prolonged sweating must be replaced to prevent imbalance in body fluids, however guidelines for this replacement are often conflicting.This study provides important information for occupational health practitioners by quantifying the likely sodium losses over a work shift and providing recommendations for replacement.

Distress or no distress, that's the question: A cutoff point for distress in a working population

Willem van Rhenen, Frank JH van Dijk, Wilmar B Schaufeli and Roland WB Blonk — 2008-01-18

Background: The objective of the present study is to establish an optimal cutoff point for distress measured with the corresponding scale of the 4DSQ, using the prediction of sickness absence as a criterion. The cutoff point should result in a measure that can be used as a credible selection instrument for sickness absence in occupational health practice and in future studies on distress and mental disorders. Methods: Distress is measured using the Four Dimensional Symptom Questionnaire (4DSQ), a 50-item self-report questionnaire, in a working population with and without sickness absence due to distress. Sensitivity and specificity were compared for various potential cutoff points, and a receiver operating characteristics analysis was conducted.Results and conclusionA distress cutoff point of ≥11 was defined. The choice was based on a challenging specificity and negative predictive value and indicates a distress level at which an employee is presumably at risk for subsequent sick leave on psychological grounds. The defined distress cutoff point is appropriate for use in occupational health practice and in studies of distress in working populations.

Disaster preparedness training for tribal leaders

Wayne F Peate and Jennie Mullins — 2008-01-15

It was with considerable irony that tribal leaders began a collaboration with the University of Arizona and the Arizona Department of Health Services for training in public health preparedness, as the tribes had an extended prior history of responding to a host of hazards caused by the dominant culture. The objective of the training was to ensure that Native American communities were adequately informed and trained to implement coordinated response plans for a range of potential public health emergencies on tribal lands and in surrounding communities. This commentary outlines how cultural competency (including public prayer by an elder during the training), respect for tribal sovereignity, solicitation of historical examples of indigenous preparedness, and incorporation of tribal community networks were essential to the success of this program.Tribal Public Health Preparedness and Response: Homeland Security Since 1492

Prevention of upper limb symptoms and signs of nerve afflictions in computer operators: The effect of intervention by stretching

Jorgen R Jepsen and Gert Thomsen — 2008-01-07

Background: In a previous study of computer operators we have demonstrated the relation of upper limb pain to individual and patterns of neurological findings (reduced function of muscles, sensory deviations from normal and mechanical allodynia of nerve trunks). The identified patterns were in accordance with neural afflictions at three specific locations (brachial plexus at chord level, posterior interosseous and median nerve on elbow level). We have introduced an intervention program aiming to mobilize nerves at these locations and tested its efficacy. Methods: 125 and 59, respectively, computer operators in two divisions of an engineering consultancy company were invited to answer a questionnaire on upper limb symptoms and to undergo a blinded neurological examination. Participants in one division were subsequently instructed to participate in an upper limb stretching course at least three times during workdays in a six month period. Subjects from the other division served as controls. At the end of the intervention both groups were invited to a second identical evaluation by questionnaire and physical examination. Symptoms and findings were studied in the right upper limb. Perceived changes of pain were recorded and individual and patterns of physical findings assessed for both groups at baseline and at follow-up. In subjects with no or minimal preceding pain we additionally studied the relation of incident pain to the summarized findings for parameters contained in the definition of nerve affliction at the three locations. Results: Summarized pain was significantly reduced in the intervention group but unchanged in controls. After the intervention, fewer neurological abnormalities in accordance with nerve affliction were recorded for the whole material but no conclusion could be drawn regarding the relation to the intervention of this reduction. Incident pain correlated to findings in accordance with the three locations of nerve affliction. Conclusion: A six month course of stretching seems to reduce upper limb symptoms in computer operators but we could not demonstrate an influence on neurological physical findings in this sample. The relation of incident symptoms to identified neurological patterns provides additional support to the construct validity of the employed neurological examination.

Lung inflammation following a single exposure to swine barn air

2007-12-18

Background: Exposure to swine barn air is an occupational hazard. Barn workers following an eight-hour work shift develop many signs of lung dysfunction including lung inflammation. However, the in situ cellular and molecular mechanisms responsible for lung dysfunction induced following exposure to the barn air remain largely unknown. Specifically, the recruitment and role of pulmonary intravascular monocytes/macrophages (PIMMs), which increase host susceptibility for acute lung inflammation, remain unknown in barn air induced lung inflammation. We hypothesized that barn exposure induces recruitment of PIMMs and increases susceptibility for acute lung inflammation with a secondary challenge. Methods: Sprague-Dawley rats were exposed either to the barn or ambient air for eight hours and were euthanized at various time intervals to collect blood, broncho-alveolar lavage fluid (BALF) and lung tissue. Subsequently, following an eight hour barn or ambient air exposure, rats were challenged either with Escherichia coli (E. coli) lipopolysaccharide (LPS) or saline and euthanized 6 hours post-LPS or saline treatment. We used ANOVA (P < 0.05 means significant) to compare group differences. Results: An eight-hour exposure to barn air induced acute lung inflammation with recruitment of granulocytes and PIMMs. Granulocyte and PIMM numbers peaked at one and 48 hour post-exposure, respectively.Secondary challenge with E. coli LPS at 48 hour following barn exposure resulted in intense lung inflammation, greater numbers of granulocytes, increased number of cells positive for TNF-α and decreased amounts of TGF-β2 in lung tissues. We also localized TNF-α, IL-1β and TGF-β2 in PIMMs. Conclusion: A single exposure to barn air induces lung inflammation with recruitment of PIMMs and granulocytes. Recruited PIMMs may be linked to more robust lung inflammation in barn-exposed rats exposed to LPS. These data may have implications of workers exposed to the barn air who may encounter secondary microbial challenge.