Do objective and subjective measures of cognitive impairment predict occupational status in patients with work-related stress? A clinical follow-up study.

OBJECTIVE: Cognitive impairment is a common complaint in prolonged work-related stress and may contribute to work disability. The objective was to evaluate the longitudinal impacts of objectively and subjectively measured cognitive impairment on occupational status and to evaluate the measurement's predictive properties regarding occupational prognosis in patients with work-related stress. METHODS: Patients with work-related stress (n = 82) were assessed with Danish versions of the Screen for Cognitive Impairment in Psychiatry (SCIP-D) and the Cognitive Failure Questionnaire (CFQ), as screeners of objective and subjective cognitive impairments, respectively. Patients were contacted via telephone at 6-month follow-up providing data on occupational status (employment vs. non-employment). Impacts of cognitive impairment on occupational status were evaluated using logistic regression analyses adjusting for other explanatory covariates (sociodemographic factors, comorbidities etc.). The predictive performance of SCIP-D and CFQ were evaluated using non-adjusted logistic regression analysis and receiver-operating-characteristics curves. RESULTS: There was a strong association between objective cognitive impairment measured with SCIP-D and non-employment when adjusting for other explanatory factors (OR adjusted 3.25, 95% CI 1.09-9.69). The association was attenuated but remained robust in the non-adjusted analysis (OR non-adjusted 1.74, 95% CI 1.08-2.81). Yet, a cut-score of SCIP-D performed inadequate as a sole predictor of occupational status. Subjective cognitive impairment was unrelated to subsequent occupational status. CONCLUSIONS: Objective-but not subjective-cognitive impairment was associated with subsequent non-employment. Our results suggest a predictive potential in objective measurements of cognitive impairment with significant implications for clinical assessment of patients with work-related stress.

Prospective, population-based study of occupational movements and postures of the neck as risk factors for cervical disc herniation.

OBJECTIVE: We studied the associations between objectively measured occupational neck exposures in a job exposure matrix (JEM) and cervical disc herniation (CDH). DESIGN: A cohort study of Danish workers who ever held at least one of 29 jobs (eg, dentists, hairdressers, childcare, carpenters) from 1981 to 2016 was formed. Representative whole work-day inclinometric measurements from previous studies using triaxial accelerometers measuring neck angular velocity and posture of the neck were used as exposure in a JEM. Job titles were retrieved from the Danish Occupational Cohort with eXposure data database. The risk of CDH by quintiles of cumulated exposure was assessed by incidence rate ratios (IRR), adjusted for age, sex, calendar-year, previous lumbar disc herniation and educational level, using Poisson regression models. SETTING: Nationwide Danish registers. PARTICIPANTS: 852 625 Danish workers within 29 different job-titles. OUTCOME MEASURES: First diagnosis of CDH was retrieved from the Danish National Patient Register. RESULTS: We found 14 000 cases of CDH during 20.2 million person-years of follow-up. Increasing levels of neck angular velocity showed a decreasing risk with IRR 0.90 (95% CI 0.86 to 0.95) when the highest level of cumulative exposure (dynamic work) was compared with the lowest (static work). Similar results were found for extension and flexion of the neck, though not statistically significant for extension. Multiple sensitivity analyses did not change the results. CONCLUSION: In this large register-based study based on a JEM, we found no evidence of an increased risk of CDH with increasing cumulated angular velocity, flexion or extension of the neck. Factors other than occupational dynamic neck movements and bent neck position seem to be important in the development of CDH.

Repetitive and forceful movements of the hand as predictors of treatment for pain in the distal upper extremities.

OBJECTIVE: To investigate repetitive movements and the use of hand force as causes of treatment for distal upper extremities musculoskeletal disorders METHODS: A cohort of 202 747 workers in a pension health scheme from 2005 to 2017 in one of 17 jobs (eg, office work, carpentry, cleaning) was formed. Representative electro-goniometric measurements of wrist angular velocity as a measure for repetition and expert-rated use of hand force were used in a job exposure matrix (JEM). Job titles were retrieved from the Danish registers. Outcome was first treatment in the distal upper extremities. In a Poisson regression model, incidence rate ratios (IRRs) of treatment were adjusted for age, calendar-year, diagnosis of rheumatoid arthritis and arm fractures. In further analyses, wrist velocity or hand force was added. RESULTS: In men, wrist velocity had an IRR of 1.48 (95% CI 1.15 to 1.91) when the highest exposure level was compared with the lowest but with no clear exposure-response pattern. The effect became insignificant when adjusted for hand force. Hand force had an IRR of 2.65 (95% CI 2.13 to 3.29) for the highest versus the lowest exposure with an exposure-response pattern, which remained after adjustment for wrist velocity. Among women, no increased risk was found for hand force, while wrist velocity showed a significantly protective association with treatment. CONCLUSIONS: In men, occupational exposure to hand force more than doubled the risk of seeking treatment. The results for exposure to repetition were less clear. In women, we could not find any indications of an increased risk neither for force nor for repetition.

Reliability and validity of expert assessments of hand-wrist physical exposures.

BACKGROUND: General population job-exposure matrices (JEMs) based on expert assessments of physical exposures may be valuable tools for studying occupation-related musculoskeletal disorders. Wrist-hand JEMs are few and the reliability and validity of expert assessments of wrist-hand exposures is uncertain. METHODS: We examined intra- and inter-rater reliability of ratings of five experts of hand-wrist repetition, deviation, force, vibration, and computer work in 33 jobs selected to represent a large exposure variation. The validity of ratings of hand-wrist repetition was examined by comparison with electro-goniometer measurements of wrist angular velocity and mean power frequency (MPF), and the validity of hand-wrist deviation by comparison with goniometer measurements of range of motion (ROM). RESULTS: Intra-rater test-retest and inter-rater Spearman correlation coefficients controlling for rater effects, varied between 0.70 and 0.87. Corresponding kappa statistics of overall agreement showed similar high values, except for wrist deviation (kappa = 0.50). Regression analyses showed strong positive associations between expert assessments of repetition and goniometer measurements of wrist angular velocity (R2 = 0.56, p < 0.0001) and MPF (R2 = 0.37, p < 0.0003), while expert ratings of wrist deviation showed a weak statistically nonsignificant association with goniometer measurements of ROM (R2 = 0.032, p = 0.34). CONCLUSION: The reliability of expert assessments of wrist-hand physical exposures was high. Compared to goniometer measurements, the validity of assessments of wrist-hand repetition was also high, but it was low for assessments of wrist-hand deviation. The results are encouraging for establishing a hand-wrist JEM, but the results for wrist deviation emphasize that expert assessments should be validated against objective measurements.

Screening for cognitive impairment among patients with work-related stress complaints in Denmark: validation and evaluation of objective and self-report tools.

OBJECTIVE: Many patients with work-related stress display cognitive impairment that may hamper recovery. We examined objective and subjective tools for screening of cognitive impairment in this patient group. METHODS: Patients were assessed with Danish versions of the objective Screen for Cognitive Impairment in Psychiatry (SCIP-D), standardized neuropsychological tests that tapped into the same cognitive domains, the self-assessed Cognitive Failure Questionnaire (CFQ), and several additional scales of symptom severity and psychosocial status. Concurrent validity of the SCIP-D and CFQ was assessed by calculation of Pearson's correlation coefficients between the objective and subjective tools and the scores on more conventional standardized neuropsychological tests. Decision validity was assessed with logistic receiver-operating-characteristic analyses using a cut-score approach to the objective and the subjective test results to predict impairment detected by the standardized tests. Cognitive norms were established through the data of 79 healthy controls. SCIP-D scores were compared between patients and healthy controls with independent t-tests. RESULTS: We included 82 patients with work-related stress. The SCIP-D total scores were strongly associated with standardized neuropsychological tests (r=0.76, P<0.001). The self-assessed CFQ was not associated with either measure of objective cognitive functioning (r≤0.12, P≥0.30). The optimal SCIP-D total-score cut of ≤72 identified 43.2% of the patients with global objective cognitive impairment. The patients performed mildly-to.moderately lower than the healthy controls on the SCIP-D total score (Cohen's d=0.39) and the subtests for working memory (d=0.39) and processing speed (d=0.61). CONCLUSION: The SCIP-D is a valid screening tool sensitive to objective performance-based cognitive impairment among patients with work-related stress.

Infrared Thermography as a Method of Verification in Raynaud's Phenomenon.

Raynaud's phenomenon (RP) is characterized by the episodic whitening of the fingers upon exposure to cold. A recently described thermographic algorithm was proposed as a diagnostic replacement of the currently applied finger systolic pressure (FSP) test. The aim of the study was to evaluate the performance of the thermographic algorithm when applied in patients suspected of having RP. Forty-three patients were examined using thermographic imaging after local cooling of the hands in water of 10 °C for 1 min. The thermographic algorithm was applied to predict the probability of RP. The performance of the algorithm was evaluated with different cut-off levels. A new algorithm was proposed based on patients from the target population. The performance of the tested algorithm was noninferior to the FSP test, when a cut-off level of 0.05 was applied, yielding a sensitivity and specificity of 69% and 58%, respectively. The accuracy was 66%. The FSP test had a sensitivity and specificity of 77% and 37%, respectively, and the accuracy was 59%. The thermographic method proved useful for detecting RP and was able to replace the FSP test as a diagnostic test. The alternative algorithm revealed that other thermographic variables were more predictive of the target population, but this should be verified in future patients.

Movements of the wrist and the risk of carpal tunnel syndrome: a nationwide cohort study using objective exposure measurements.

OBJECTIVES: We conducted a large cohort study to investigate the association between work-related wrist movements and carpal tunnel syndrome (CTS). METHODS: Electro-goniometric measurements of wrist movements were performed for 30 jobs (eg, office work, child care, laundry work and slaughterhouse work). We measured wrist angular velocity, mean power frequency (MPF) and range of motion (ROM). We established a cohort of Danish citizens born 1940-1979 who held one of these jobs from age 18-80 years, using Danish national registers with annual employment information from 1992 to 2014. We updated the cohort by calendar year with job-specific and sex-specific means of measured exposures. Dates of a first diagnosis or operation because of CTS were retrieved from the Danish National Patient Register. The risk of CTS by quintiles of preceding exposure levels was assessed by adjusted incidence rate ratios (IRRadj) using Poisson regression models. RESULTS: We found a clear exposure-response association between wrist angular velocity and CTS with an IRRadj of 2.31 (95% CI 2.09 to 2.56) when exposed to the highest level compared with the lowest. MPF also showed an exposure-response pattern, although less clear, with an IRRadj of 1.83 (1.68 to 1.98) for the highest compared with the lowest exposure level. ROM showed no clear pattern. Exposure-response patterns were different for men and women. CONCLUSIONS: High levels of wrist movement were associated with an increased risk of CTS. Preventive strategies should be aimed at jobs with high levels of wrist movements such as cleaning, laundry work and slaughterhouse work.

Emotional demands and exhaustion: cross-sectional and longitudinal associations in a cohort of Danish public sector employees.

PURPOSE: To examine cross-sectional and longitudinal associations between content-related emotional demands at work and exhaustion, and to investigate if these associations were modified by other psychosocial work characteristics. METHODS: In 2007, 4489 Danish public service employees participated in the PRISME study by completing postal questionnaires, and 3224 participated in the follow-up in 2009. Content-related emotional demands were measured by a scale (scored 1 to 5) based on five work-content-related items, and exhaustion was measured with the general exhaustion scale from the Copenhagen Burnout Inventory (CBI) (scored 1 to 5). The cross-sectional and longitudinal associations with exhaustion were analysed in the same model and adjusted for effects of potential confounders. Effect modifications were examined separately for self-reported emotional enrichment, meaningful work, job control, social support at work and quantitative demands. RESULTS: Exhaustion increased with increasing emotional demands, both cross-sectionally and longitudinally. However, although statistically significant, the effect was small. In the longitudinal analysis, a one unit increase in emotional demands was associated with a 0.03 unit (95% CI: 0.01-0.06) increase in exhaustion. We found statistically significant effect modification for three of six potentially modifying work characteristics. The effect of emotional demands on exhaustion was lower for participants with high levels of emotional enrichment (cross-sectionally and longitudinally), high levels of meaningful work (longitudinally), and higher for high levels of quantitative demands (cross-sectionally). CONCLUSIONS: Increasing content-related emotional demands were associated with increasing levels of exhaustion, cross-sectionally and longitudinally. This effect was reduced if the work was experienced as emotionally enriching and meaningful.

Does Workplace Bullying Affect Long-Term Sickness Absence Among Coworkers?

AIM: To examine if non-bullied employees at work units (WUs) with workplace bullying have more long-term sickness absence (LTSA) than employees in non-bullying WUs. METHODS: We included 7229 public health employees from 302 WUs and 3158 responders to a questionnaire on working conditions and health in 2007. WUs were classified into three categories of WUs; (1) no bullying (0% bullied); (2) moderate prevalence of bullying (less than 10% bullied); and (3) high prevalence of bullying (more than or equal to 10% bullied). LTSA (more than or equal to 30 consecutive days of sickness absence) during the following 2 years was obtained by linkage to the Danish register of sickness absence compensation benefits and social transfer payments. RESULTS: Non-bullied coworkers in WUs, where bullying was reported had 15% to 22% more LTSA compared with non-bullying WUs. CONCLUSION: Workplace bullying may be associated with LTSA in the entire WU.

Prolonged perceived stress and saliva cortisol in a large cohort of Danish public service employees: cross-sectional and longitudinal associations.

PURPOSE: It is well known that acute stress can lead to a transient increase in cortisol secretion, but the effects of prolonged stress on cortisol secretion are uncertain. This study examines the cross-sectional and longitudinal associations between prolonged perceived stress and salivary cortisol. METHODS: In 2007, 4467 Danish public service employees participated in a study of stress and mental health, and 3217 participated in a follow-up in 2009. Perceived stress during the past 4 weeks was assessed by Cohen's four item perceived stress scale. Participants were asked to collect saliva 30 min after awakening and at approximately 20:00 in the evening. The cortisol dependence on perceived stress was examined in regression analyses adjusted for effects of potential confounders. We adjusted for a large variation in saliva sampling times by modelling the time trajectory of cortisol concentrations in the morning and in the evening and examined if they were influenced by perceived stress. RESULTS: Perceived stress had no statistically significant effects on the level or time trajectory of morning or evening cortisol, neither cross-sectionally nor longitudinally. The 1 month prevalence of frequently perceived stress was low, approximately 2.5%. CONCLUSION: Our results did not support the hypothesis that prolonged perceived stress is associated with the level or time trajectory of morning or evening salivary cortisol.

Effect of Integrated Pest Management Training on Ugandan Small-Scale Farmers.

Small-scale farmers in developing countries use hazardous pesticides taking few or no safety measures. Farmer field schools (FFSs) teaching integrated pest management (IPM) have been shown to reduce pesticide use among trained farmers. This cross-sectional study compares pesticide-related knowledge, attitude, practice (KAP), potential exposure, and self-reported poisoning symptoms among 35 FFS farmers, 44 neighboring farmers, and 35 control farmers after an IPM intervention in Uganda (2011-2012). The FFS farmers were encouraged to teach their neighboring farmers. Data were based on standardized interviews and were analyzed using a linear trend test and logistic regression. The results showed that FFS and neighboring farmers used significantly fewer pesticide applications (P = .021) and used more safety measures. No differences were found on the hazardousness of pesticides used or self-reported symptoms. The study supports IPM as a method to reduce pesticide use and potential exposure and to improve pesticide-related KAP among small-scale farmers in developing countries.

The use of self-reported symptoms as a proxy for acute organophosphate poisoning after exposure to chlorpyrifos 50% plus cypermethrin 5% among Nepali farmers: a randomized, double-blind, placebo-controlled, crossover study.

BACKGROUND: Previous studies stating a high prevalence of occupational acute pesticide poisoning in developing countries have mainly relied on measurements of the rather non-specific self-reported acute pesticide poisoning symptoms. Only a few studies have measured the biomarker plasma cholinesterase (PchE) activity, in addition to the symptoms, when assessing occupational acute pesticide poisoning. This study evaluated self-reported symptoms as a proxy for acute organophosphate poisoning among Nepali farmers by examining self-reported acute organophosphate poisoning symptoms and PchE activity in response to occupational acute organophosphate exposure. METHODS: We performed a randomized, double-blind, placebo-controlled, crossover trial among 42 Nepali commercial vegetable farmers. The farmers were randomly assigned (ratio 1:1) to a 2-h organophosphate (chlorpyrifos 50% plus cypermethrin 5%: moderately hazardous) spray session or a 2-h placebo spray session, and after 7 days' washout, the farmers were assigned to the other spray session. Before and after each spray session farmers were interviewed about acute organophosphate poisoning symptoms and PchE activity was measured. Analyses were conducted with a Two Sample T-test and Mann Whitney U-test. RESULTS: We found no difference in the symptom sum or PchE activity from baseline to follow up among farmers spraying with organophosphate (symptom sum difference -1, p = 0.737; PchE mean difference 0.02 U/mL, p = 0.220), placebo (symptom sum difference 9, p = 0.394; PchE mean difference 0.02 U/mL, p = 0.133), or when comparing organophosphate to placebo (symptom p = 0.378; PchE p = 0.775). However, a high percentage of the farmers reported having one or more symptoms both at baseline and at follow up in the organophosphate spray session (baseline 47.6%, follow up 45.2%) and placebo spray session (baseline 35.7%, follow up 50.0%), and 14.3% of the farmers reported three or more symptoms after the organophosphate spray session as well as after the placebo spray session. CONCLUSION: We found a general presence of acute organophosphate symptoms among the farmers regardless of organophosphate exposure or poisoning. Thus, self-reported acute organophosphate symptoms seem to be a poor proxy for acute organophosphate poisoning as the occurrence of these symptoms is not necessarily associated with acute organophosphate poisoning. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02838303 . Registered 19 July 2016. Retrospectively registered.

Exposure-response relationships between movements and postures of the wrist and carpal tunnel syndrome among male and female house painters: a retrospective cohort study.

OBJECTIVES: To investigate exposure-response relationships between measured movements and postures of the wrist and the incidence of carpal tunnel syndrome (CTS), and any modifications by sex. METHODS: In 2011, we established a historical cohort of 9364 members of the Painters' Union in Denmark. Self-reported task distributions were obtained by questionnaire (53% responded) and combined with sex-specific task exposure matrices to get individual estimates of exposure intensity, that is, velocity of wrist flexion/extension, mean power frequency (MPF) and non-neutral wrist postures. Exposure duration was assessed from yearly working proportions. Registered first-time hospital discharge CTS diagnoses and CTS surgery were collected as outcomes. The cohort was followed from 1994 to 2010. Log-linear Poisson regression was used. RESULTS: For CTS diagnoses, the adjusted incidence rate ratios (IRRs) increased with increasing wrist velocity (IRR=1.37 (95% CI 1.10 to 1.71) per °/s) and MPF (IRR=1.53 (95% CI 1.21 to 1.91) per 0.01 Hz). For CTS surgery, the results were similar. The outcomes were not related to non-neutral postures or exposure duration. The adjusted IRRs for women were higher than those for men. There were no multiplicative interaction effects between exposure intensity, exposure duration and sex. However, the absolute incidence rates (IRs) increased at a steeper rate for women than for men, indicating an additive interaction. CONCLUSIONS: The incidence of CTS increased with increasing velocity of wrist flexion/extension and MPF of wrist movements. The relative increase in incidence rates was the same for women and men, but the absolute incidence rates increased at a steeper rate for women than for men.

Varicose veins in the lower extremities in relation to occupational mechanical exposures: a longitudinal study.

OBJECTIVES: To evaluate if occupational mechanical exposures are associated with an increased risk of surgery for varicose veins (VV) in the lower extremities. METHODS: We conducted a longitudinal study of persons from the Musculoskeletal Research Database at the Danish Ramazzini Centre who were 18-65 years old when they provided baseline questionnaire data during 1993-2004. Exposure estimates were obtained from a job exposure matrix based on expert ratings. The register information on first-time surgery for VV was retrieved. We used Cox regression analyses. RESULTS: During 416,317 person-years of follow-up among 38,036 persons, 851 first-time operations for VV occurred. Using standing/walking <4 h/day and uncommon lifting as references, exposure-response relationships with risk of surgery were found for men. For women, the risk increased too, but without clear exposure-response patterns. The adjusted HRs for ≥6 h/day spent standing/walking were 3.17 (95% CI 2.06 to 4.89) and 2.34 (95% CI 1.72 to 3.19) for men and women, respectively. For high lifting exposures (≥1000 kg/day), the adjusted HRs were 3.95 (95% CI 2.32 to 6.73) for men and 2.54 (95% CI 1.95 to 3.31) for women. Other risk factors were increasing age for men and parity for women. Minimal leisure-time physical activity, a high body mass index and smoking were not associated with increased risk. CONCLUSIONS: The results suggested an increased risk of surgery for VV in relation to prolonged standing/walking and heavy lifting and a preventive potential of more than 60% of all cases in exposed occupations.

Exposure to workplace bullying and risk of depression.

OBJECTIVE: We examined the prospective association between self-labeled and witness-reported bullying and the risk of newly onset of depression. METHODS: Employees were recruited from two cohorts of 3196 and 2002 employees, respectively. Participants received a questionnaire at baseline in 2006 to 2007 with follow-up in 2008 to 2009 and 2011. New cases of depression were diagnosed in the follow-up using Schedules for Clinical Assessment in Neuropsychiatry interviews and the Major Depression Inventory questionnaire. RESULTS: We identified 147 new cases of depression. The odds ratio for newly onset depression among participants reporting bullying occasionally was 2.17 (95% confidence interval [CI]: 1.11 to 4.23) and among frequently bullied 9.63 (95% CI: 3.42 to 27.1). There was no association between percentage witnessing bullying and newly onset depression. CONCLUSIONS: Frequent self-labeled bullying predicts development of depression but a work environment with high proportion of employees witnessing bullying does not.

Sex differences in muscular load among house painters performing identical work tasks.

PURPOSE: The present study aimed to estimate possible differences in upper body muscular load between male and female house painters performing identical work tasks. Sex-related differences in muscular load may help explain why women, in general, have more musculoskeletal complaints than men. METHODS: In a laboratory setting, 16 male and 16 female house painters performed nine standardised work tasks common to house painters. Unilateral electromyography (EMG) recordings were obtained from the supraspinatus muscle by intramuscular electrodes and from the trapezius, extensor and flexor carpi radialis muscles by surface electrodes. Relative muscular loads in %EMGmax as well as exerted force in Newton, based on ramp calibrations, were assessed. Sex differences were tested using a mixed model approach. RESULTS: Women worked at about 50% higher relative muscular loads than men in the supraspinatus and forearm muscles at all percentiles and in all tasks. Women exerted about 30% less force in the trapezius muscle at the 50th percentile. CONCLUSIONS: Female house painters had a higher relative muscular load than their male colleagues without exerting more force. The effects of a higher relative muscular load accumulated over years of work may in part explain why musculoskeletal complaints in the upper body occur more frequently among women than men.

Salivary cortisol and depression in public sector employees: cross-sectional and short term follow-up findings.

INTRODUCTION: Increased cortisol levels have been suggested to play a role in the development of depression. An association has been shown in some studies but not consistently. The timing of an association is uncertain, and long-term follow-up studies may miss associations in narrower time windows. In the present study, we examined the association of several cortisol measures and depression in a repeated cross-sectional and short-term follow-up design. Depression was assessed by both self-reported symptoms of depression and clinical interviews. METHOD: In 2007, 10,036 public sector employees received a questionnaire along with salivary cortisol test tubes for home administration. Morning (30min after awakening) and evening (2000h) salivary samples were collected. Questionnaires and valid saliva samples were returned from 3536 employees. Approximately 3.6 months later a subsample of the participants collected three morning saliva samples (at awakening, 20min and 40min after awakening) plus an evening sample (2000h); participants with high baseline scores of self-reported depressive symptoms, burnout and perceived stress were invited to a standardized interview (SCAN) to detect clinical depression; and the symptom questionnaire was repeated for subsample participants. The study was repeated in 2009 with questionnaires and salivary test tubes (n=2408). In four cross-sectional and two short-term follow-up analyses odds ratios of depressive symptoms and of clinical depression were estimated by logistic regression for morning, evening, mean and the difference between morning and evening cortisol (slope). For the subsample, awakening response (CAR) and area under the curve (AUC) cortisol measures were calculated. We adjusted for sex, age, income, education, family history of depression, physical activity and alcohol consumption. RESULTS: None except one of the measures of salivary cortisol were associated with self-reported depressive symptoms or clinical depression, neither in the four cross-sectional analyses nor in the two short term follow-up analyses. E.g. in 2007, the adjusted odds ratios (OR) of depressive symptoms by a one unit increase in morning and evening cortisol (ln(nmol/litre saliva)) were 1.01 (95% CI: 0.88-1.17) and 1.05 (0.93-1.18), respectively. The one exception was significant at p=0.04 and was considered as due to chance. CONCLUSION: In this large study, salivary cortisol was not associated with self-reported symptoms of depression or with clinical depression.

A review of mercury exposure among artisanal small-scale gold miners in developing countries.

PURPOSE: Extraction of gold using mercury has been a way out of poverty for millions of people in developing countries. Artisanal small-scale gold mining (ASGM) has expanded during the last decades and is often carried out under primitive conditions. Thus, workers in this industry may be exposed to high levels of mercury and suffer from toxic effects from mercury exposure. The objective of this review was to provide an outline of the studies available on elemental mercury exposure among artisanal small-scale gold miners. METHODS: Searching the PubMed and Embase databases, 26 studies with a total of 3,005 exposed subjects and 442 controls across 14 different developing countries were found. Urine mercury levels were used as biomarkers of exposure. RESULTS: In general, the urine mercury levels were elevated and a considerable proportion of workers had urine mercury levels above existing guidelines. Exposed subjects were stratified into residents, miners, millers, smelters, and refiners, who by work task content were expected to be increasingly exposed to mercury. This group order did show a clear trend of increasing mercury levels. Mercury levels differed substantially between studies. Possible explanations include dissimilarities in gold extraction methods, use of protective devices, and selection of participants. CONCLUSIONS: This review provides evidence that artisanal gold miners and residents of the mining sites are exposed to mercury vapour to an extent where acute and long-term toxic effects of mercury are likely. Interventions aimed at reducing exposure and emission of mercury from ASGM are needed.