Journal of Occupational Medicine and Toxicology - Latest Articles

Results of five-year systematic screening for latent tuberculosis infection in healthcare workers in Portugal

Jose Torres Costa — 2010-07-26T00:00:00Z

IntroductionThe risk of tuberculosis (TB) in healthcare workers (HCWs) is related to its incidence in the general population, and increased by the specific risk as a professional group. The prevalence of latent tuberculosis infection (LTBI) in HCWs in Portugal using the tuberculin skin test (TST) and the interferon-gamma release assays (IGRA) was analyzed over a five-year period. Methods: A screening programme for LTBI in HCWs was conducted, with clinical evaluations, TST, IGRA, and chest radiography. Putative risk factors for LTBI were assessed by a standardised questionnaire. Results: Between September 2005 and June 2009, 5,414 HCWs were screened. The prevalence of LTBI was 55.2% and 25.9% using a TST [greater than or equal to] 10 mm or an IGRA test result (QuantiFERON-TB Gold In-Tube) INF-gamma [greater than or equal to] 0.35 IU/mL as a criterion for LTBI, respectively. In 53 HCWs active TB was diagnosed. The number of HCWs with newly detected active TB decreased from 19 in the first year to 6 in 2008. Risk assessment was poorly related to TST diameter. However, physicians (1.7%) and nurses (1.0%) had the highest rates of active TB. Conclusions: LTBI and TB burden among HCWs in Portugal is high. The screening of these professionals to identify HCWs with LTBI is essential in order to offer preventive chemotherapy to those with a high risk of future progression to disease. Systematic screening had a positive impact on the rate of active TB in HCWs either by early case detection or by increasing the awareness of HCWs and therefore the precautions taken by them.

Nerve conduction in relation to vibration exposure - a non-positive cohort study

Helena Sanden — 2010-07-19T00:00:00Z

Background: Peripheral neuropathy is one of the principal clinical disorders in workers with hand-arm vibration syndrome. Electrophysiological studies aimed at defining the nature of the injury have provided conflicting results. One reason for this lack of consistency might be the sparsity of published longitudinal etiological studies with both good assessment of exposure and a well-defined measure of disease. Against this background we measured conduction velocities in the hand after having assessed vibration exposure over 21 years in a cohort of manual workers. Methods: The study group consisted of 155 male office and manual workers at an engineering plant that manufactured pulp and paper machinery. The study has a longitudinal design regarding exposure assessment and a cross-sectional design regarding the outcome of nerve conduction. Hand-arm vibration dose was calculated as the product of self-reported occupational exposure, collected by questionnaire and interviews, and the measured or estimated hand-arm vibration exposure in 1987, 1992, 1997, 2002, and 2008. Distal motor latencies in median and ulnar nerves and sensory nerve conduction over the carpal tunnel and the finger-palm segments in the median nerve were measured in 2008. Before the nerve conduction measurement, the subjects were systemically warmed by a bicycle ergometer test. Results: There were no differences in distal latencies between subjects exposed to hand-arm vibration and unexposed subjects, neither in the sensory conduction latencies of the median nerve, nor in the motor conduction latencies of the median and ulnar nerves. Seven subjects (9%) in the exposed group and three subjects (12%) in the unexposed group had both pathological sensory nerve conduction at the wrist and symptoms suggestive of carpal tunnel syndrome. Conclusion: Nerve conduction measurements of peripheral hand nerves revealed no exposure-response association between hand-arm vibration exposure and distal neuropathy of the large myelinated fibers in a cohort of male office and manual workers.

Intention as an indicator for subjective need: A new pathway in need assessment

Uwe Rose — 2010-07-12T00:00:00Z

Background: The current analyses focus on the need for services from the perspective of individuals considering preventive measures. A new approach imported from social and health psychology is used for assessing subjective need. This indicator is used for predicting actual health behaviour under field conditions and simultaneously other relevant background variables are taken into account. Methods: A mail survey was conducted prior to the start of a coaching program for teachers. A sample of n = 949 respondents were queried about mental distress and their intention to participate in the program. This intention to participate and actual attendance were taken as outcome variables in logistic regression analyses adjusted for relevant background variables. Results: Intention and participation in the coaching program three months later were associated with an unadjusted OR of 90.1 (95% CI: 39.2 - 207.0) for male teachers. For female teachers the crude effect was OR = 80.0 (95% CI: 45.7 - 140.1). The positive predictive value (PPV) was 96.4% among males and 94.5% among females. Adjusting for covariates results in higher values. Among female, but not among male teachers, the participation depended on psychological distress as assessed by the General Health Questionnaire (GHQ). Conclusions: There is strong evidence for using subjective need as an additional component in assessing the need for services and for predicting actual health behaviour. But it needs to be confined to intended behaviour which is under behavioural control.

Acute lead intoxication in a female battery worker: Diagnosis and managment

George Dounias — 2010-07-07T00:00:00Z

Lead is a significant occupational and environmental hazard. Battery industry is one of the settings related to lead intoxication. Published information on the use of oral chelating agents for the treatment of anaemia in the context of acute lead intoxication is limited. The patient was a 33 year immigrant female worker in a battery manufacture for 3 months. She complained for malaise that has been developed over the past two weeks. Pallor of skin and conjunctiva was the only sign found in physical examination. The blood test on admission revealed normochromic anaemia. Endoscopic investigation of the gastrointestinal system was negative for bleeding. The bone marrow biopsy was unrevealing.At baseline no attention has been paid to patient's occupational history. Afterwards the patient's occupational history has been revaluated and she has been screened for lead intoxication. The increased levels of the lead related biomarkers of exposure and effect confirmed the diagnosis. The patient received an oral chelating agent and an improvement in clinical picture, and levels of haematological and lead related biochemical parameters have been recorded. No side effect and no rebound effect were observed. This case report emphasizes the importance of the occupational history in the context of the differential diagnosis. Moreover, this report indicates that lead remains an occupational hazard especially in the small scale battery industry

The impact of shift work induced chronic circadian disruption on IL-6 and TNF-alpha immune responses

Anke van Mark — 2010-07-05T00:00:00Z

AIM: Sleep disturbances induce proinflammatory immune responses, which might increase cardiovascular disease risk. So far the effects of acute sleep deprivation and chronic sleep illnesses on the immune system have been investigated. The particular impact of shift work induced chronic circadian disruption on specific immune responses has not been addressed so far.MethodS: Pittsburgh-Sleep-Quality-Index (PSQI) questionnaire and blood sampling was performed by 225 shift workers and 137 daytime workers. As possible markers the proinflammatory cytokines IL-6 and TNF-alpha and lymphocyte cell count were investigated. A medical examination was performed and biometrical data including age, gender, height, weight, waist and hip circumference and smoking habits were collected by a structured interview. Results: : Shift workers had a significantly higher mean PSQI score than day workers (6.73 vs. 4.66; p < 0.001). Day workers and shift workers had similar serum levels of IL-6 (2.30 vs. 2.67 resp.; p = 0.276), TNF-alpha (5.58 vs. 5.68, resp.; p = 0.841) or lymphocytes count (33.68 vs. 32.99, resp.; p = 0.404). Furthermore there were no differences in cytokine levels (IL-6 p = 0.761; TNF-alpha p = 0.759) or lymphocyte count (p = 0.593) comparing the sleep quality within the cohorts. When this calculation of sleep quality was stratified by shift and day workers irrespective of their sleep quality day workers and shift workers had similar serum levels of IL-6, TNF-alpha or lymphocytes count. Multiple linear regression analysis showed a significant correlation of lymphocytes count and smoking habits.CONCLUSION: Shift work induces chronic sleep debt. Our data reveals that chronic sleep debt might not always lead to an activation of the immune system, as we did not observe differences in lymphocyte count or level of IL-6 or TNF-alpha serum concentration between shift workers and day workers. Therefore chronic sleep restriction might be eased by a long-term compensating immune regulation which (in healthy) protects against an overstimulation of proinflammatory immune mechanisms and moderates metabolic changes, as they are known from short-term sleep deprivation or sleep related breathing disorders.

Inhibition of gap junctional intercellular communication in WB-F344 rat liver epithelial cells by triphenyltin chloride through MAPK and PI3-kinase pathways

Chung-Hsun Lee — 2010-06-30T00:00:00Z

Background: Organotin compounds (OTCs) have been widely used as stabilizers in the production of plastic, agricultural pesticides, antifoulant plaints and wood preservation. The toxicity of triphenyltin (TPT) compounds was known for their embryotoxic, neurotoxic, genotoxic and immunotoxic effects in mammals. The carcinogenicity of TPT was not well understood and few studies had discussed the effects of OTCs on gap junctional intercellular communication (GJIC) of cells.MethodIn the present study, the effects of triphenyltin chloride (TPTC) on GJIC in WB-F344 rat liver epithelial cells were evaluated, using the scrape-loading dye transfer technique. Results: TPTC inhibited GJIC after a 30-min exposure in a concentration- and time-dependent manner. Pre-incubation of cells with the protein kinase C (PKC) inhibitor did not modify the response, but the specific MEK 1 inhibitor PD98059 and PI3K inhibitor LY294002 decreased substantially the inhibition of GJIC by TPTC. After WB-F344 cells were exposed to TPTC, phosphorylation of Cx43 increased as seen in Western blot analysis. Conclusions: These results show that TPTC inhibits GJIC in WB-F344 rat liver epithelial cells by altering the Cx43 protein expression through both MAPK and PI3-kinase pathways.

Bidirectional Assessment of Stress, job satisfaction and work ability of Educators in day care centres: a real-time observation study - the study protocol (BASE)

Bianca Kusma — 2010-06-29T00:00:00Z

Background: Occupational demands of educators are not very well researched. Nevertheless their work is subject to several requirements. Whether these demands have an effect on the work ability and the health status of employees has also not been examined. Furthermore it is unclear if the ownership type of day care centres have an influence on job satisfaction and work ability of the pedagogical staff and what kind of resources do exist. Previous studies were mainly based on questionnaire data. Objective data does not exist. Therefore the aim of this investigation is to collect precise data relating to work of educators. Methods: Effects of different types of ownership of day care centres on job satisfaction and work ability of educators will be assessed with the help of objective real time studies in combination with multi-level psycho diagnostic measurements.DiscussionThe present study is the first of its kind. Up to now there are no computer-based real time studies on workflow of pedagogical staff with regard to assess their work-related stress. Following an exhaustive documentation of educators work processes the day-to-day task can be estimated and approaches for prevention can be developed. This can substantially contribute to an overall improvement of child care in Germany.

Retrospective exposure assessment to airborne asbestos among power industry workers

Michael Felten — 2010-06-25T00:00:00Z

Background: A method of individually assessing former exposure to asbestos fibres is a precondition of risk-differentiated health surveillance. The main aims of our study were to assess former levels of airborne asbestos exposure in the power industry in Germany and to propose a basic strategy for health surveillance and the early detection of asbestos related diseases. Methods: Between March 2002 and the end of 2006, we conducted a retrospective questionnaire based survey of occupational tasks and exposures with airborne asbestos fibres in a cohort of 8632 formerly asbestos exposed power industry workers. The data on exposure and occupation were entered into a specially designed computer programme, based on ambient monitoring of airborne asbestos fibre concentrations. The cumulative asbestos exposure was expressed as the product of the eight-hour time weighted average and the total duration of exposure in fibre years (fibres/cubic centimetre-years). Results: Data of 7775 (90% of the total) participants working in installations for power generation, power distribution or gas supply could be evaluated. The power generation group (n = 5284) had a mean age of 56 years, were exposed for 20 years and had an average cumulative asbestos exposure of 42 fibre years. The occupational group of "metalworkers" (n = 1600) had the highest mean value of 79 fibre years. The corresponding results for the power distribution group (n = 2491) were a mean age of 45 years, a mean exposure duration of 12 years and an average cumulative asbestos exposure of only 2.5 fibre years. The gas supply workers (n = 512) had a mean age of 54 years and a mean duration of exposure of 15 years. Conclusions: While the surveyed cohort as a whole was heavily exposed to asbestos dust, the power distribution group had a mean cumulative exposure of only 6% of that found in the power generation group. Based on the presented data, risk-differentiated disease surveillance focusing on metalworkers and electricians from the power generating industry seems justified. That combined with a sensitive examination technique would allow detecting asbestos related diseases early and efficiently.

Occupational risk of overweight and obesity: an analysis of the Australian Health Survey

Margaret Allman-Farinelli — 2010-06-16T00:00:00Z

Background: Adults spend about one third of their day at work and occupation may be a risk factor for obesity because of associated socioeconomic and behavioral factors such as physical activity and sedentary time. The aim of this study was to examine body mass index (BMI) and prevalence of overweight and obesity by occupation and explore the contributions of socioeconomic factors and lifestyle behaviors (including leisure time and commuting physical activity, diet, smoking, and alcohol) to occupational risk. Methods: Secondary analyses of the National Health Survey in Australia (2005) were conducted for working age adults (20 to 64 years). Linear and logistic regression models using BMI as either dichotomous or continuous response were computed for occupation type. Model 1 was age-adjusted, Model 2 adjusted for age and socioeconomic variables and Model 3 adjusted for age, socioeconomic variables and lifestyle behaviours. All models were stratified by gender. Results: Age-adjusted data indicated that men in associate professional (OR 1.34, 95% CI 1.10-1.63) and intermediate production and transport (OR 1.24 95% CI 1.03-1.50) occupations had a higher risk of BMI ≥ 25 kg/m2 than those without occupation, and women in professional (OR 0.71, 95% CI 0.61-0.82), management (OR 0.72, 95% CI 0.56-0.92) and advanced clerical and service occupations (OR 0.73 95% CI 0.58-0.93) had a lower risk. After adjustment for socioeconomic factors no occupational group had an increased risk but for males, professionals, tradesmen, laborers and elementary clerical workers had a lower risk as did female associate professionals and intermediate clerical workers. Adjustment for lifestyle factors explained the lower risk in the female professional and associate professionals but failed to account for the lower odds ratios in the other occupations. Conclusions: The pattern of overweight and obesity among occupations differs by gender. Healthy lifestyle behaviors appear to protect females in professional and associate professional occupations from overweight. For high-risk occupations lifestyle modification could be included in workplace health promotion programs. Further investigation of gender-specific occupational behaviors and additional lifestyle behaviors to those assessed in the current Australian Health Survey, is indicated.

Use of alcohol and drugs by Norwegian employees: a pilot study using questionnaires and analysis of oral fluid

Hallvard Gjerde — 2010-06-15T00:00:00Z

Background: The use of alcohol and drugs may affect workplace safety and productivity. Little is known about the magnitude of this problem in Norway. Methods: Employee recruitment methods with or without individual follow-up were compared. The employees filled in a questionnaire and provided a sample of oral fluid. Samples were analysed for alcohol, ethyl glucuronide (EtG; a biological marker of recent large alcohol intake), psychoactive medicinal drugs and illegal drugs. Results: Participation rates with and without individual follow-up were 96% and 68%, respectively. Alcohol was negative (≤0.1 mg/ml) in all samples, but 21.0% reported the intake of alcohol during the last 24 h. EtG was positive (>2.2 ng/ml) in 2.1% of the samples. In-efficiency or hangover at work during the past year was reported by 24.3%, while 6.2% had been absent from work due to the use of alcohol. The combination of self-report and analytical testing indicated that medicinal or illegal drugs had been used during the last 48 h by 5.1% and 1.7% of the participants, respectively; while only 4.2% and 0.4% admitted the use in the questionnaire. Conclusions: Self-reported data suggest that hangover after drinking alcohol appears to be the largest substance abuse problem at Norwegian workplaces, resulting in absence and inefficiency at work. Analysis of oral fluid revealed that the use of illegal drugs was more common than drinking alcohol before working or at the workplace. The analysis of oral fluid may be a valuable tool in obtaining additional information on alcohol and drug use compared to using questionnaires alone.