Retirement status and frailty: a cross-sectional study of the phenotype of manual workers aged 50-70 years.

BACKGROUND: The frailty phenotype is predictive of mortality and has been identified in the working population. This cross-sectional study aimed to investigate the prevalence of frailty and individual frailty symptoms among active and retired Danish manual workers and to delineate the relationship between frailty and lifestyle factors. METHODS: Manual workers aged 50-70 years answered questions relating to the Fried criteria for frailty (weight loss, exhaustion, slowness, weakness and inactivity). Only men were included in the analyses and respondents were stratified according to work status: active workers (n = 1555), early retirees (n = 289) and workers retired at or after normal pension age (n = 291). Associations between pre-frailty/frailty, work status and various lifestyle factors were estimated using binomial logistic regression. RESULTS: Overall, the prevalence of pre-frailty (one or two symptoms) and frailty (three or more symptoms) was 33.3% and 1.5%, respectively. Those who had retired early were more likely to be pre-frail/frail compared with active workers (odds ratio 2.20, 95% CI 1.61-3.01). Exhaustion was the most prominent symptom reported by 22.2% of active workers, 34.6% of early retirees and 16.5% of workers retired at normal retirement age. Lifestyle factors including obesity, physical inactivity and smoking but not alcohol intake were associated with pre-frailty/frailty. CONCLUSION: Symptoms of frailty are identifiable and present among both active and retired manual workers. Data suggest discrepancies among Danish manual workers, with some having unhealthy lifestyles and being more prone to develop pre-frailty and frailty already in their sixth decade of life.

Asbestos exposure and haematological malignancies: a Danish cohort study.

Environmental asbestos exposure and occupational asbestos exposure increase the risk of several types of cancer, but the role of such exposures for haematological malignancies remains controversial. We aimed to examine the risk of haematological malignancies: first, in subjects exposed early in life, independently of any occupational exposure occurring later; second, in subjects exposed occupationally. We established an environmentally exposed cohort from four schools located near the only former asbestos cement production plant in Denmark. We identified nearly all pupils in the seventh grade and created an age and sex-matched 1:9 reference cohort from the Danish Central Population Register. Participants were born 1940-1970 and followed up in national registers until the end of 2015. Occupational asbestos exposure was assessed for all participants using two different job exposure matrices. The school cohort included 12,111 participants (49.7% girls) and the reference cohort 108,987 participants. Eight subgroups of haematological malignancy were identified in the Danish Cancer Registry. These cases were analysed for combined overall haematological malignancy, a combined subgroup of lymphomas and a combined subgroup of leukaemias. The data were analysed using Cox regression (hazard ratios (HR)) including other cancers and death as competing risks. Haematological malignancy was identified in 1125 participants. The median follow-up was 49.3 years (0.1-63.4). Early environmental asbestos exposure was not associated with an increased risk of haematological malignancy. Long-term occupational asbestos exposure was associated with overall haematological malignancy (HR 1.69, 95% CI 1.04-2.73); in particular for the leukaemia subgroup (HR 2.14, 95% CI 1.19-3.84). This large follow-up study suggests that long-term occupational asbestos exposure is associated with increased leukaemia risk. However, further studies are needed to confirm these observations.

Environmental asbestos exposure in childhood and risk of mesothelioma later in life: a long-term follow-up register-based cohort study.

OBJECTIVE: To examine the risk of malignant mesothelioma (MM) in former pupils who attended primary school near an asbestos cement plant. METHODS: A cohort of 12 111 former pupils, born 1940-1970, was established from individual historical records from four primary schools located at a distance of 100-750 m in the prevailing wind direction from an asbestos cement plant operating from 1928 to 1984 in Aalborg, Denmark. The school cohort and a comparison cohort consisting of 108 987 gender and 5-year frequency-matched subjects were followed up (2015) for MM in the Danish Cancer Registry. Using Cox regression, HRs were estimated for the incidence of MM. Adjustments for occupational and familial asbestos exposure were made with a job exposure matrix. An SIR analysis including latency periods testing the cancer incidence rate was performed with the comparison cohort as the reference rate. RESULTS: The median person-years of follow-up were 62.5 years in the school cohort and 62.2 years in the comparison cohort. There were 32 males and 6 females of the former pupils who developed MM during the follow-up: HRmale 7.01 (95% CI 4.24 to 11.57), HRfemale 7.43 (95% CI 2.50 to 22.13). Those who attended school 250 m north of the plant had the highest HR for MM, 10.65 (95% Cl 5.82 to 19.48). No significant trend between school distance and risk of MM was established (p=0.35). CONCLUSION: Our results suggest that boys and girls who attended schools and lived in the neighbourhood of an asbestos cement plant later in life have a significantly increased risk of MM.

A nationwide follow-up study of occupational organic dust exposure and risk of chronic obstructive pulmonary disease (COPD).

OBJECTIVES: To study exposure-response relations between cumulative organic dust exposure and incident chronic obstructive pulmonary disease (COPD) among subjects employed in the Danish farming and wood industry. METHODS: We studied exposure-response relations between cumulative organic dust exposure and incident COPD (1997-2013) among individuals born during 1950-1977 in Denmark ever employed in the farming or wood industry (n=1 75 409). Industry-specific employment history (1964-2007), combined with time-dependent farming and wood industry-specific exposure matrices defined cumulative exposure. We used logistic regression analysis with discrete survival function adjusting for age, sex and calendar year. Adjustment for smoking status was explored in a subgroup of 4023 with smoking information available. RESULTS: Cumulative organic dust exposure was inversely associated with COPD (adjusted rate ratios (RRadj (95% CIs) of 0.90 (0.82 to 0.99), 0.76 (0.69 to 0.84) and 0.52 (0.47 to 0.58) for intermediate-low, intermediate-high and high exposure quartiles, respectively, compared with the lowest exposure quartile). Lagging exposure 10 years was not consistently suggestive of an association between cumulative exposure and COPD; RRadj (95% CI): 1.05 (0.94 to 1.16), 0.92 (0.83 to 1.02) and 0.63 (0.56 to 0.70). Additional stratification by duration of employment showed no clear association between organic dust exposure and COPD except for the longer exposed (15-40 years) where an inverse association was indicated. Subgroup analyses showed that smoking had no impact on exposure-response estimates. CONCLUSIONS: Our findings show no increased risk of COPD with increasing occupational exposure to organic dust in the farming or wood industry. Potential residual confounding by smoking can, however, not be ruled out.

An outreach collaborative model for early identification and treatment of mental disorder in Danish workplaces.

BACKGROUND: Depression and anxiety are prevalent mental disorders among the working population with potentially high personal and financial cost. The overall aim of this study was to test the applicability of an outreach collaborative model for early identification and treatment of clinical and sub-clinical mental disorders among Danish employees. This applicability was examined by I) investigating the fractions of identified and treated clinical and subclinical cases, II) describing the distribution and characteristics of cases identified and III) investigating the effect of allocated treatment. METHODS: A longitudinal study design with four assessments (T0-T3) over 16 months was applied. Self-reporting questionnaires probing for psychopathology were distributed to all employees in six consecutively enrolled companies at the four time points. Employees meeting the screening criteria at T1 were assessed diagnostically. Subjects diagnosed with a clinical mental disorder were allocated to outpatient psychiatric treatment, and subjects with subclinical conditions were allocated to preventive cognitive behavioural therapy. Follow-up was conducted 6 and 12 months after initiation of treatment. We used chi-squared test and F-test to compare the different groups on baseline characteristics and mixed effects linear regression to analyse the treatment effects. RESULTS: Forty (6.8%) of the 586 responders at T1 were diagnosed with a clinical mental disorder and referred to outpatient psychiatric treatment. Thirty-three (5.6%) were affected by a subclinical condition and referred to preventive treatment. Nearly two-thirds (63%) of the employees diagnosed with a clinical condition had never received treatment before. Symptom severity decreased significantly for both treated groups until follow-up. When compared to a composed control group, subclinical cases displayed a more rapid initial significant symptomatic decrease on the global symptom scale (coefs = - 0.914, 95% CI [- 1.754, - 0,075]) and anxiety sub-scale (coefs = - 1.043, 95% CI [- 2.021, - 0.066]). This did not apply to the clinical cases as no significant difference in change were identified. CONCLUSIONS: The outreach collaborative model demonstrated an applicability to identify both clinical and subclinical cases, among these a high number of employees with an unmet need for treatment. We found evidence of a positive initial effect on symptomatology from the allocated preventive treatment among the subclinical cases, but not for clinical cases. TRIAL REGISTRATION: Retrospectively registered at December 18, 2018 at clinicaltrials.gov, identifier: NCT03786328 .

Physical-work ability and chronic musculoskeletal complaints are related to leisure-time physical activity: Cross-sectional study among manual workers aged 50-70 years.

AIMS: To investigate the associations between both high- and low-intensity leisure-time physical activity on physical-work ability and chronic musculoskeletal complaints among manual workers aged 50-70 years. METHODS: In this cross-sectional study, 1763 manual workers (mean age 57.1, SD ± 4.7 years) replied to questions about leisure-time physical activity, physical-work ability, chronic musculoskeletal complaints as well as health and lifestyle factors. Ordinal and binomial logistic regression models were constructed to assess the influence of the duration of both low- and high-intensity physical activity on physical-work ability and chronic musculoskeletal complaints, respectively. Models were adjusted for gender, age, smoking, alcohol intake, body mass index, physical-work demand, work experience, chronic disease and, regarding physical-work ability, also for chronic musculoskeletal complaints. RESULTS: A statistically significant association between greater physical-work ability and high-intensity physical activity was found for workers engaged in 3-4 h/wk and ⩾ 5 h/wk (OR 1.59, 95% CI 1.15-2.19 and OR 1.56, 95% CI 1.10-2.22, respectively). For both high- and low-intensity physical activity, a duration of 3-4 h/wk was associated with lower odds of reporting chronic musculoskeletal complaints in the knees (OR 0.65, 95% CI 0.42-1.00 and OR 0.61, 95% CI 0.38-0.99, respectively). CONCLUSIONS: Engaging in ⩾ 3 h/wk of high-intensity leisure-time physical activity was associated with greater physical-work ability among manual workers aged 50-70 years. Both high- and low-intensity physical activity related to lower odds of having chronic musculoskeletal complaints in the knees.

High exposure to endotoxin in farming is associated with less new-onset pollen sensitisation.

OBJECTIVES: Little is known about risk factors for new onset and loss of atopic sensitisation in adulthood. The aim is to examine the longitudinal effect of quantitatively assessed endotoxin exposures on changes in specific allergen sensitisation in young adults. METHODS: The cohort consisted of 1113 young Danish farmers and rural controls, with a mean age of 19 years at baseline. Sensitisation to birch pollen, grass pollen, cat dander and house dust mite was measured by specific IgE levels in serum samples from baseline and at 15 years' follow-up. Changes in sensitisation were analysed in relation to cumulative endotoxin exposure during follow-up, considering early life farm exposure. RESULTS: Endotoxin exposure during follow-up was significantly associated with less new onset of specifically grass and birch pollen sensitisation. For the highest versus lowest quartile of cumulative endotoxin exposure, the OR for new-onset IgE sensitisation was 0.35 (0.13-0.91) for birch and 0.14 (0.05-0.50) for grass. On the other hand, loss of pollen sensitisation showed a positive, although mostly non-significant, association with increased levels of endotoxin exposure. Endotoxin exposure was not associated with significant changes in cat dander and house dust mite sensitisation. CONCLUSIONS: High exposure to endotoxin during young adulthood appears to protect against new onset of pollen sensitisation, independent of childhood farm exposure.

Feedback on Measured Dust Concentrations Reduces Exposure Levels Among Farmers.

BACKGROUND: The high burden of exposure to organic dust among livestock farmers warrants the establishment of effective preventive and exposure control strategies for these workers. The number of intervention studies exploring the effectiveness of exposure reduction strategies through the use of objective measurements has been limited. OBJECTIVE: To examine whether dust exposure can be reduced by providing feedback to the farmers concerning measurements of the exposure to dust in their farm. METHODS: The personal dust levels of farmers in 54 pig and 26 dairy cattle farms were evaluated in two measurement series performed approximately 6 months apart. Detailed information on work tasks and farm characteristics during the measurements were registered. Participating farms were randomized a priori to a control (n = 40) and an intervention group (n = 40). Shortly after the first visit, owners of intervention farms only received a letter with information on the measured dust concentrations in the farm together with some general advises on exposure reduction strategies (e.g. use of respirators during certain tasks). Relationships between measured dust concentrations and intervention status were quantified by means of linear mixed effect analysis with farm and worker id as random effects. Season, type of farming, and work tasks were treated as fixed effects. Changes in exposure over time were explored primarily at a farm level in models combined, as well as separate for pig and cattle farmers. RESULTS: After adjustment for fixed effects, an overall reduction of 23% in personal dust exposures was estimated as a result of the intervention (P = 0.02). Exposure reductions attributable to the intervention were similar across pig and cattle farmers, but statistically significant only for pig farmers. Intervention effects among pig farmers did not depend on the individuals' information status; but among cattle farmers a significant 48% reduction in exposure was found only among individuals that reported to have been informed. No systematic differences in changes over time considering the use of respiratory protection between the intervention and control groups were observed. CONCLUSION: The results of the present study suggest reductions between 20 and 30% in personal exposure to inhalable dust to be feasible through simple information provided to the farm owners regarding actual levels of exposure together with instructions on basic measures of prevention. The exact reasons for these effects are unclear, but likely they involve changes in behavior and working practices among intervention farmers.

Occupational COPD among Danish never-smokers: a population-based study.

Occupational exposures have been shown to be risk factors for chronic obstructive pulmonary disease (COPD) among never-smokers. In a Danish population-based cohort, we analysed this association and the population attributable fraction. The study population (N=1575) was aged 45-84, COPD was defined by lung function measurements and the method of lower limit of normal (LLN), and occupational exposure was assessed by questionnaire and expert judgement. Furthermore, the estimates additionally were provided according to the Global Initiative for Chronic Obstructive Lung Diseases. More than a threefold increased risk (LLN OR=3.69 (95% CI 1.36 to 10.04) was found for occupational exposure to vapour, gas, dust and fumes (predominantly organic dust) in this never-smoking population, with a corresponding 48% (95% CI 30% to 65%) population attributable fraction among never-smokers.

The effect of occupational farming on lung function development in young adults: a 15-year follow-up study.

OBJECTIVES: Longitudinal studies on the effect of farming on lung function in young participants are few. Our objective was to explore if exposure to farming impaired lung function in young adults. METHODS: We studied 1964 farming students and 407 controls in 1992/2004, and carried out follow-up in 2007/2008. Spirometry, skin prick test and bronchial hyper-responsiveness (BHR) were assessed, height and weight measured, and questionnaires covering health and occupation were collected. Cumulative dust and endotoxin exposures were estimated from modelled personal dust measurements. Lung function effect was expressed as change in z-score during follow-up using the Global Lung Initiative 2012 project prediction equations. Longitudinal data were available for 1134 young participants ≤25 years at baseline. RESULTS: We found no differences in lung function Δz-scores between farmers and controls, however, adjusted multivariable linear regression showed a negative effect among current farmers on ΔzFEV1 (forced expiratory volume in 1 s; -0.12, p=0.006) and ΔzFEV1/FVC (forced vital capacity; -0.15, p=0.009) compared to ex-farmers. An interaction was found between sex and farming, showing that current farming suppresses ΔzFEV1 and ΔzFVC more among females. Smoking in farmers had a deleterious effect on ΔzFEV1, which was not seen in controls, though no significant interaction was found. Farm upbringing protected against impairment of lung function, and BHR at baseline had a deleterious effect on ΔzFEV1 only in those not raised on a farm. CONCLUSIONS: We conclude that being a current farmer is associated with a negative effect on lung function, when compared to ex-farmers, with females being more susceptible. Being raised on a farm protects against the adverse effect of BHR on change in lung function.

Are allergen batch differences and the use of double skin prick test important?

BACKGROUND: Skin prick tests (SPT) are widely used both in clinical diagnostics and in research. The standardization of allergen extracts is well documented to be crucial for the validity of SPT, whereas less emphasis has been placed on reproducibility and the SPT procedure itself. The objectives of this study are to clarify how the double skin prick test procedure influence the sensitivity and specificity of the test and to analyse the differences in weal size in skin prick tests between two batches of allergen extracts from the same vendor. METHODS: The association between rhinitis and SPT was assessed among 1135 persons from a general population sample. SPT was performed twice with 10 common aeroallergens. In a subsample of 90 persons SPT was performed simultaneously with five of the allergens using different batches. RESULTS: Thirty percent had at least one positive SPT. Among asthmatics this number was 62%. Only minor differences were seen between the sizes of two weals from the same batch. A second SPT with the same batch did not change the association between rhinitis and sensitization. When performing SPT with two different batches disagreement was observed in 2% (Birch) to 11% (Cat) of the subjects. CONCLUSIONS: Performing SPT twice with the same allergen batch does not enhance the validity of the test, and value of double testing can be questioned. Considerable differences in SPT response with different batches from the same manufacturer were observed. Thus inter batch differences in allergen extracts might be a source of variability.

Occupational Chronic Obstructive Pulmonary Disease in a Danish Population-Based Study.

The aim was to explore the impact of occupation on chronic obstructive pulmonary disease (COPD) in a cross-sectional population-based study among subjects aged 45 to 84 years. In a stratified sampling 89 general practitioners practices (GPP) in Denmark recruited 3106 males and 1636 females through the Danish Civil Registration System. COPD was defined by spirometry by the 2.5(th)-centile Lower Limit of Normal of FEV1 and FEV1/FVC. Information about smoking, occupational exposure and the respective occupations were obtained from questionnaires. Occupations followed the Danish adaptation of The International Standard Classification of Occupations, revision 1988 (DISCO-88). Exposure to vapour, gas, dust (organic and inorganic), and fume (VGDF) in each occupation (yes/no) was evaluated by two independent specialist in occupational medicine. Exposures were divided in no, low, medium, and high exposure as 0, < 5, 5-14, and ≥ 15 years in the job, respectively. Data was analysed by a mixed random effect logistic regression model. The age-standardised COPD study prevalence was 5.0%. Of 372 DISCO-88 codes 72 were identified with relevant exposure to VGDF. 46% of the participants reported at least one occupation with VGDF exposure. Adjusted for smoking, age, sex, and GPP a dose-dependent association of COPD was found among workers in jobs with high organic dust exposure, with OR 1.56 (95% CI 1.09-2.24). Restricted to agriculture the OR was 1.59 (95% CI: 1.08-2.33). No association was observed for workers in jobs with inorganic dust, fume/gas, or vapour exposures. In summary, occupational organic dust exposure was associated to the prevalence of COPD.

Exposure-affecting factors of dairy farmers' exposure to inhalable dust and endotoxin.

INTRODUCTION: Studies on determinants of dairy farmers' exposure to dust and endotoxin have been sparse and so far none has addressed the combined effect of tasks and farm characteristics. OBJECTIVE: To study whether and how work tasks and specific stable characteristics influence the level of dairy farmers' personal exposure to inhalable dust and endotoxin. METHODS: We applied an observational design involving full-shift repeated personal measurements of inhalable dust and endotoxin exposure among 77 subjects (owners and farm workers) from 26 dairy farms. Performed tasks were self-registered in activity diaries, and information on stable characteristics was collected through personal interviews and walk-through surveys. Associations between exposure, tasks, and stable characteristics were examined in linear mixed-effect models with individual and farm treated as random effects. Separate as well as combined models for tasks and stable characteristics were elaborated. RESULTS: The 124 personal samples collected had a geometric mean level (geometric standard deviation) of 360 EU m(-3) (3.8) for endotoxin exposure and of 1.0mg m(-3) (2.7) for dust exposure. Identified factors that increased endotoxin exposure included a lower outdoor temperature and use of slope-based or back-flushed slurry systems along with milking, distribution of bedding, and handling of feed and seeds in barns. For dust, exposure was higher when fully automatic (robotic) milking was used and during re-penning of animals, handling of feed and seeds, handling of silos and when distributing bedding. Dust exposure increased also as a result of use of rail feed dispensers in a model without fully automatic milking. CONCLUSIONS: The current exposure to dust and in particular endotoxin among Danish dairy farmers demand effective strategies to reduce their exposure. The present findings suggest that future interventions should focus on feeding and manure handling systems. Use of respirators during handling of feed and distribution of bedding should be advised until adequate risk management measures have been established. The expected increased use of fully automatic milking in the future might increase dust exposure of dairy farmers.

Mechanistic experimental pain assessment in computer users with and without chronic musculoskeletal pain.

BACKGROUND: Musculoskeletal pain from the upper extremity and shoulder region is commonly reported by computer users. However, the functional status of central pain mechanisms, i.e., central sensitization and conditioned pain modulation (CPM), has not been investigated in this population. The aim was to evaluate sensitization and CPM in computer users with and without chronic musculoskeletal pain. METHODS: Pressure pain threshold (PPT) mapping in the neck-shoulder (15 points) and the elbow (12 points) was assessed together with PPT measurement at mid-point in the tibialis anterior (TA) muscle among 47 computer users with chronic pain in the upper extremity and/or neck-shoulder pain (pain group) and 17 pain-free computer users (control group). Induced pain intensities and profiles over time were recorded using a 0-10 cm electronic visual analogue scale (VAS) in response to different levels of pressure stimuli on the forearm with a new technique of dynamic pressure algometry. The efficiency of CPM was assessed using cuff-induced pain as conditioning pain stimulus and PPT at TA as test stimulus. RESULTS: The demographics, job seniority and number of working hours/week using a computer were similar between groups. The PPTs measured at all 15 points in the neck-shoulder region were not significantly different between groups. There were no significant differences between groups neither in PPTs nor pain intensity induced by dynamic pressure algometry. No significant difference in PPT was observed in TA between groups. During CPM, a significant increase in PPT at TA was observed in both groups (P < 0.05) without significant differences between groups. For the chronic pain group, higher clinical pain intensity, lower PPT values from the neck-shoulder and higher pain intensity evoked by the roller were all correlated with less efficient descending pain modulation (P < 0.05). CONCLUSIONS: This suggests that the excitability of the central pain system is normal in a large group of computer users with low pain intensity chronic upper extremity and/or neck-shoulder pain and that increased excitability of the pain system cannot explain the reported pain. However, computer users with higher pain intensity and lower PPTs were found to have decreased efficiency in descending pain modulation.

Exposure to inhalable dust and endotoxin among Danish pig farmers affected by work tasks and stable characteristics.

OBJECTIVE: To identify working tasks and stable characteristics that determine intensity and variability of personal exposure to dust and endotoxin among pig farmers. METHODS: Three hundred fifty-four personal full-shift measurements were performed in 231 farmers employed in 53 Danish pig farms. Filters were gravimetrically analysed for inhalable dust and for endotoxin by the Limulus amebocyte lysate assay. Information on working tasks and stable characteristics were collected using self-reported activity diaries and walk-through surveys performed in conjunction with the measurements. Associations between log-transformed dust and endotoxin exposure and working tasks and stable characteristics were examined using linear mixed-effects analysis. In these models, worker and farm identity were treated as random effects and working tasks and stable characteristics as fixed effects. Both separate and combined models for tasks and stable characteristics were elaborated. RESULTS: Inhalable dust concentrations ranged between 0.1 and 48 mg m(-3) and endotoxin concentrations varied between 9.2 and 370,000 EU m(-3). Field work activities played a dominant role on the exposure variability. Indoor working tasks with intense animal activity or handling of feed materials increased exposure concentrations, whereas engagement in field work was associated with lower exposure concentrations. High-pressure water cleaning increased endotoxin exposure but did not affect exposure to inhalable dust. Stable characteristics related to feeding practices and type of ventilation were determinants of exposure to inhalable dust. For endotoxin, the most important determinants were use of dry feed and slatted floor coverage. Feeding practices solely explained all between-farms variability in exposure to inhalable dust and endotoxin. CONCLUSIONS: These findings suggest feeding systems, flooring and ventilation to be potential areas where improved methods can reduce exposure to dust and endotoxin among pig farmers. Further, they highlight particular tasks involving feeding and intense animal handling as sources of very high levels of exposure. The pig farming industry is encouraged to focus on exposure reduction. Use of respirators during performance of working tasks where levels of exposure are particularly high ought to be considered until adequate hygienic solutions have been established.

Impact of organisational change on mental health: a systematic review.

Although limited evidence is available, organisational change is often cited as the cause of mental health problems. This paper provides an overview of the current literature regarding the impact of organisational change on mental health. A systematic search in PUBMED, PsychInfo and Web of Knowledge combining MeSH search terms for exposure and outcome. The criterion for inclusion was original data on exposure to organisational change with mental health problems as outcome. Both cross-sectional and longitudinal studies were included. We found in 11 out of 17 studies, an association between organisational change and elevated risk of mental health problems was observed, with a less provident association in the longitudinal studies. Based on the current research, this review cannot provide sufficient evidence of an association between organisational change and elevated risk of mental health problems. More studies of long-term effects are required including relevant analyses of confounders.

Sensitisation to common allergens and respiratory symptoms in endotoxin exposed workers: a pooled analysis.

OBJECTIVE: To test the hypotheses that current endotoxin exposure is inversely associated with allergic sensitisation and positively associated with non-allergic respiratory diseases in four occupationally exposed populations using a standardised analytical approach. METHODS: Data were pooled from four epidemiological studies including 3883 Dutch and Danish employees in veterinary medicine, agriculture and power plants using biofuel. Endotoxin exposure was estimated by quantitative job-exposure matrices specific for the study populations. Dose-response relationships between exposure, IgE-mediated sensitisation to common allergens and self-reported health symptoms were assessed using logistic regression and generalised additive modelling. Adjustments were made for study, age, sex, atopic predisposition, smoking habit and farm childhood. Heterogeneity was assessed by analysis stratified by study. RESULTS: Current endotoxin exposure was dose-dependently associated with a reduced prevalence of allergic sensitisation (ORs of 0.92, 0.81 and 0.66 for low mediate, high mediate and high exposure) and hay fever (ORs of 1.16, 0.81 and 0.58). Endotoxin exposure was a risk factor for organic dust toxic syndrome, and levels above 100 EU/m(3) significantly increased the risk of chronic bronchitis (p<0.0001). Stratification by farm childhood showed no effect modification except for allergic sensitisation. Only among workers without a farm childhood, endotoxin exposure was inversely associated with allergic sensitisation. Heterogeneity was primarily present for biofuel workers. CONCLUSIONS: Occupational endotoxin exposure has a protective effect on allergic sensitisation and hay fever but increases the risk for organic dust toxic syndrome and chronic bronchitis. Endotoxin's protective effects are most clearly observed among agricultural workers.

Consequences of asthma on job absenteeism and job retention.

AIMS: Various social and economic effects are associated with asthma. This quantitative study describes the effects of current asthma on work life evaluated from the number of weeks receiving transfer incomes. METHODS: The study population comprised 7,241 persons answering the ECRHS II screening questionnaire, which was sent to a random age and gender stratified sample of 10,000 persons aged 20 to 44 years. Participants with current asthma were identified by positive answers to a set of validated questions. Transfer incomes for a five-year period were registered from a study-independent national database, which collects all public administered transfer incomes in Denmark. The numbers of weeks receiving unemployment, welfare, sick-leave and disability benefits were identified for each participant and differences between asthmatics and non-asthmatics were analyzed. RESULTS: Asthmatics had significantly more annual weeks receiving welfare (36.6 vs. 20.7, p=0.00), sick leave (9.2 vs. 6.6, p=0.00) and disability (19.3 vs. 11.4, p=0.00) benefits than non-asthmatics. Adult-onset asthmatics had increased prevalence rate ratios for disability of 2.40 (95% confidence interval 1.70-3.40). Blue collar work significantly increased the probability of all public transfer incomes. CONCLUSIONS: Current asthma makes it harder to keep a job. Adult-onset asthmatics and blue collar workers are particularly affected.

Exposure to inhalable dust and endotoxin among Danish livestock farmers: results from the SUS cohort study.

Studies on personal dust and endotoxin concentrations among animal farmers have been either small or limited to a few sectors in their investigations. The present study aimed to provide comparable information on the levels and variability of exposure to personal dust and endotoxin in different types of animal farmers. 507 personal inhalable dust samples were collected from 327 farmers employed in 54 pig, 26 dairy, 3 poultry, and 3 mink farms in Denmark. Measurements in pig and dairy farmers were full-shift and performed during summer and winter, while poultry and mink farmers were monitored during 4 well-defined production stages. The collected samples were measured for dust gravimetrically and analyzed for endotoxin by the Limulus amebocyte lysate assay. Simple statistics and random-effect analysis were used to describe the levels and the variability in measured dust and endotoxin exposure concentrations. Measured inhalable dust levels had an overall geometric mean of 2.5 mg m(-3) (range