Impact of psychosocial work factors on risk of medically certified sick leave due to common mental disorders: a nationwide prospective cohort study of Norwegian home care workers.

BACKGROUND: The Norwegian home care services experience a high level of sick leave, a large proportion of which is due to common mental disorders. A substantial number of such cases can be attributed to psychosocial factors at work, but more knowledge about occupation-specific risk factors is needed to develop targeted preventive measures to reduce sick leave levels. The aim of this study is to identify the most prominent psychosocial work factors influencing the risk of sick leave spells due to common mental disorders. METHODS: Employees from a random sample of 130 Norwegian home care services (N = 1.819) completed a baseline survey on 15 psychosocial work factors. Participants were subsequently followed up for 26 months using registry data on sick leave. The outcome measure was the number of medically certified sick leave spells due to common mental disorders during follow-up in the Norwegian social insurance database. Incidence risk ratios (IRR) and 95% confidence intervals (CIs) were calculated using negative binomial regression with robust standard errors. RESULTS: Emotional dissonance (IRR 1.30, 95% CI 1.05-1.60) and emotional demands (IRR 1.35, 95% CI 1.14-1.58) were associated with an excess risk of sick leave, while control over work pacing (IRR 0.78, 95% CI 0.62-0.98) was associated with a reduced risk. An estimated 30% (95% CI 8.73-48.82) of sick leave cases were attributable to emotional dissonance and 27% (95% CI 4.80-46.33) were attributable to emotional demands. Control over work pacing was estimated to have prevented 20% (95% CI 1.32-37.78) of the sick leave cases. CONCLUSIONS: This study found that emotional dissonance and emotional demands were robust risk factors for sick leave due to common mental disorders, and that control of work pacing constituted a robust protective factor against sick leave.

Effects of the Labor Inspection Authority's regulatory tools on physician-certified sick leave and employee health in Norwegian home-care services - a cluster randomized controlled trial.

OBJECTIVE: This study aimed to determine the effects of the Labor Inspection Authority's regulatory tools on physician-certified sick leave and self-reported health outcomes among employees in municipal home-care services in Norway. METHODS: We conducted a cluster-randomized controlled trial in the home-care service sector, and 96 eligible municipalities were randomly assigned to one of three groups: (i) labor inspection visits, based on the Labor Inspection Authority's standard inspections; (ii) guidance-through-workshops, where participants from home-care services met with labor inspectors to receive information and discuss relevant topics; and (iii) the control group. Data on employee self-reported health (N=1669) were collected at baseline and 6 and 12 months after the interventions. Additionally, registry data (N=1202) on diagnosis specific physician-certified sick leave were collected for 18 months after the interventions. RESULTS: We found no statistically significant effects of either intervention on self-reported health outcomes. There was, for both interventions, a pattern of decrease in days and periods of physician-certified sick leave due to musculoskeletal diagnoses and increase in days and periods of physician-certified sick leave due to psychological diagnoses, but these were not statistically significant. CONCLUSION: Labor inspections and guidance-through-workshops had no statistically significant effect on self-reported health and physician-certified sick leave. The results should be interpreted with caution given the low response rate and subsequent attrition, and in the context of the COVID-19 pandemic. Future studies, in various industries, should further elucidate whether regulatory tools influence employee health and sick leave due to musculoskeletal and mental disorders.

A cross-sectional study of sensory-motor neuropsychological function among sewage plant and sewage net workers exposed to hydrogen sulphide when handling wastewater.

OBJECTIVES: Workers at sewage treatment plants are exposed to a complex mixture of toxins, including hydrogen sulphide (H2S). An issue of concern among sewage workers, is possible negative nervous system effects from low-level H2S exposure. Empirical neuropsychological evidence indicates both that low-dose exposure to H2S exposure affects the nervous system, and the contrary, that such exposure may facilitate nervous system function, since H2S is an endogenously produced central nervous system (CNS) gasotransmitter. The aim of this study is to describe a possible association between the H2S component of the total exposure and long-term effects on neuropsychological motor function among wastewater workers. METHODS: Workers (N = 138) treating wastewater in 6 sewage-treatment plants, or in the sewer net system participated in a cross-sectional study. H2S exposure was expressed in a dichotomous exposure variable defining currently H2S-exposed (N = 112) and unexposed referent workers (N = 26), and a variable defining a job-exposure matrix for long-term total typical workplace H2S exposure. The participants went through neuropsychological tests for hand coordination, reaction time (SRT), and balance, and completed questionnaires. Pearson chi-square test or independent samples t-test was used when comparing the currently H2S-exposed workers with the unexposed control group. Multiple linear regression was used to assess associations between the independent variables age, smoking and exposure variables, and the neuropsychological tests. RESULTS: The analyses indicate increased SRT in the currently H2S-exposed group compared to controls (mean [SD] = 225.8 [29.9] versus 210.7 [26.3] ms, P = 0.019), and an association between increased SRT and current H2S-exposure in the total study sample (ß = 14.7, P = 0.026, R2 = 0.06, P = 0.050). Blindfolded balance testing indicates a nonsignificant trend in the total study sample, of reduced balance in the highest versus lowest H2S total long-term exposure-index group (Sway area [mean {SD}, mm2: 702 [410] versus 581 [278]), and a significant association between total long-term H2S exposure and reduced balance among smokers (Sway area, mm2 [ß = 38.7, P = 0.039], mean sway, mm [ß = 0.3, P = 0.015]). CONCLUSION: The observed trends and associations may be due to exposure peaks in certain work operations and pinpoint the importance of minimizing and avoiding exposure peaks, also when H2S time-weighted average measurements do not exceed an occupational exposure limit of 5 ppm.

Content of clinker and other materials in personal thoracic aerosol samples from cement plants estimated by scanning electron microscopy and energy-dispersive X-ray microanalysis.

OBJECTIVES: To estimate the composition and exposure to clinker and other specific components in personal thoracic dust samples of cement production workers. METHODS: A procedure for the classification of airborne particles in cement production plants was developed based on classification trees. For this purpose, the chemical compositions of 27,217 particles in 29 material samples (clinker, limestone, gypsum, clay, quartz, bauxite, iron source, coal fly ash, and coal) were determined automatically by scanning electron microscopy (SEM) and energy-dispersive X-ray microanalysis (EDX). The concentrations of the major elements in cement (calcium, aluminium, silicon, iron, and sulphur) were used for the classifications. The split criteria of the classification trees obtained in the material samples were used to classify 44,176 particles in 34 personal thoracic aerosol samples. The contents of clinker and other materials were estimated, and the clinker contents were analysed statistically for differences between job types and job tasks. RESULTS: Between 64% and 88% of the particles from material samples were classified as actual materials. The material types with variable composition (clay, coal fly ash, and coal) were classified with the lowest consistency (64% to 67%), while materials with a more limited compositional variation (clinker, gypsum, and quartz) were classified more consistently (76% to 85%). The arithmetic mean (AM) of the clinker content in personal samples was 62.1%, the median was 55.3%, and 95% confidence interval (CI) was 42.6% to 68.1%. No significant differences were observed between job types. However, the clinker content in samples when workers handled materials with high clinker content was significantly higher than when materials with lower clinker content were handled, 85% versus 65% (P = 0.02). The limestone content was AM 14.8%, median 13.2% (95% CI 5.5 to 20.9), whereas the other materials were present with relative abundances of median ≤ 6.4%. DISCUSSION: Automated particle analysis by SEM-EDX followed by classification tree analysis quantified clinker with fairly high consistency when evaluated together with raw materials that are expected to be airborne in cement production plants. The clinker proportions for job types were similar. Tasks a priori ranked by assumed clinker content were significantly different and according to expectations, which supports the validity of the chosen methodology. CONCLUSIONS: The composition of personal samples of mineral aerosols in the cement production industry could be estimated by automated single particle analysis with SEM-EDX and classification by a classification tree procedure. Clinker was the major component in the thoracic aerosol that cement production workers were exposed to. Differences between job types were relatively small and not significant. The clinker content from tasks was in agreement with assumptions.

High aspect ratio nanomaterial-induced macrophage polarization is mediated by changes in miRNA levels.

Introduction: Inhalation of nanomaterials may induce inflammation in the lung which if left unresolved can manifest in pulmonary fibrosis. In these processes, alveolar macrophages have an essential role and timely modulation of the macrophage phenotype is imperative in the onset and resolution of inflammatory responses. This study aimed to investigate, the immunomodulating properties of two industrially relevant high aspect ratio nanomaterials, namely nanocellulose and multiwalled carbon nanotubes (MWCNT), in an alveolar macrophage model. Methods: MH-S alveolar macrophages were exposed at air-liquid interface to cellulose nanocrystals (CNC), cellulose nanofibers (CNF) and two MWCNT (NM-400 and NM-401). Following exposure, changes in macrophage polarization markers and secretion of inflammatory cytokines were analyzed. Furthermore, the potential contribution of epigenetic regulation in nanomaterial-induced macrophage polarization was investigated by assessing changes in epigenetic regulatory enzymes, miRNAs, and rRNA modifications. Results: Our data illustrate that the investigated nanomaterials trigger phenotypic changes in alveolar macrophages, where CNF exposure leads to enhanced M1 phenotype and MWCNT promotes M2 phenotype. Furthermore, MWCNT exposure induced more prominent epigenetic regulatory events with changes in the expression of histone modification and DNA methylation enzymes as well as in miRNA transcript levels. MWCNT-enhanced changes in the macrophage phenotype were correlated with prominent downregulation of the histone methyltransferases Kmt2a and Smyd5 and histone deacetylases Hdac4, Hdac9 and Sirt1 indicating that both histone methylation and acetylation events may be critical in the Th2 responses to MWCNT. Furthermore, MWCNT as well as CNF exposure led to altered miRNA levels, where miR-155-5p, miR-16-1-3p, miR-25-3p, and miR-27a-5p were significantly regulated by both materials. PANTHER pathway analysis of the identified miRNA targets showed that both materials affected growth factor (PDGF, EGF and FGF), Ras/MAPKs, CCKR, GnRH-R, integrin, and endothelin signaling pathways. These pathways are important in inflammation or in the activation, polarization, migration, and regulation of phagocytic capacity of macrophages. In addition, pathways involved in interleukin, WNT and TGFB signaling were highly enriched following MWCNT exposure. Conclusion: Together, these data support the importance of macrophage phenotypic changes in the onset and resolution of inflammation and identify epigenetic patterns in macrophages which may be critical in nanomaterial-induced inflammation and fibrosis.

The Prolonged Effect of Shift Work and the Impact of Reducing the Number of Nightshifts on Arterial Stiffness-A 4-Year Follow-Up Study.

AIM: To assess changes in blood pressure (BP) and arterial stiffness among 84 rotating shift and 25 dayworkers (control subjects) at two industrial plants during a 4-year follow-up, and to assess changes in outcome variables among shift workers at the two plants after a reduction in the number of night shifts during the last year of follow-up in one of the plants. METHODS: We collected demographic data using a questionnaire, examined systolic and diastolic blood pressure (sBP, dBP), central systolic and diastolic aorta pressure (cSP, cDP), augmentation pressure (AP), central pulse pressure (cPP), and pulse wave velocity (PWV). We registered sleep quality. The last 4-14 months of follow-up one plant implemented a 12-week shift plan reducing the total number of night shifts and consecutive night shifts from 16.8 to 14 and from 7.2 to 4. To assess differences in change of outcomes between study groups we applied linear mixed models. RESULTS: The dayworkers were older, more hypertensive, reported less sleep disturbance, and smoked/snuffed less than the shift workers did. The adjusted annual increase in PWV was 0.34 m/s (95%CI, 0.22, 0.46) among shift workers and 0.09 m/s (95%CI, -0.05, 0.23) in dayworkers, yielding a significant difference of change of 0.25 m/s (95%CI, 0.06, 0.43). No significant differences were found between the two groups of shift workers in any cardiovascular disease (CVD) outcome during the last year of follow-up. CONCLUSIONS: Shift work in industry is associated with arterial stiffness, reflecting an increased risk of future CVD. No significant changes in arterial stiffness were identified as a consequence of a small reduction in the number of night shifts and consecutive night shifts.

Exposure to Particulate Matter and Respirable Crystalline Silica in Tunnel Construction Workers Using Tunnel Boring Machines.

OBJECTIVES: This study aimed to assess the exposure to a selection of aerosols and gases in the work environment for workers performing tunnel construction using tunnel boring machines (TBMs), to identify determinants of exposure based on the information available and to calculate robust estimates of exposure using a statistical model. The focus was particulate matter (PM) and respirable crystalline silica (RCS). In addition, concentrations of nitrogen dioxide (NO2), elemental carbon (EC), and oil mist were assessed. METHODS: Personal sampling was conducted from February 2017 to February 2019. PM in the thoracic and the respirable aerosol fractions was collected, and RCS was determined in the respirable aerosol fraction. Context information was collected on questionnaires. Because the workers could participate in the sampling more than once and multiple measurements were performed on the same date a mixed model was used in the analysis. Concentrations of PM and RCS are presented as estimated and measured geometric means (GMest and GMmea) and estimated arithmetic mean (AMest) in addition to the median. Measured concentrations of NO2, EC, and oil mist are presented as geometric means. RESULTS: A total of 290 and 289 personal samples of PM in the thoracic and respirable aerosol fractions were available for analysis, respectively. Work title/work location, type of work (production, maintenance, or a combination of the two), and date of sampling were identified as determinants of exposure. Workers in the front of the TBMs had the highest exposure to PM and RCS. The GMest of RCS exposure varied from 35 to 413 µg m-3 depending on the work title. The geometric standard deviations for measured RCS concentrations by work title ranged from 1.6 to 3.5. A total of 16 samples of NO2 and EC and 12 samples of oil mist were collected. Maximum values of NO2 and EC were 54 µg m-3 and 23 µg m-3, respectively. The maximum measured value of oil mist was 0.08 mg m-3. CONCLUSIONS: All TBM workers were exposed to PM and RCS. Exposure to RCS may be substantial, and workers in front of the TBM were exposed to the highest concentrations of both PM and RCS. A day-to-day variation was found, probably caused by differences in drilling activities. Preventive measures are warranted to keep the exposure to PM and consequently the exposure to RCS as low as possible to protect the health of workers in tunnel construction.

Influence of Shift Work on Arterial Stiffness and Systemic Inflammation: A 3-Year Follow-up Study in Industry.

OBJECTIVE: To assess changes in cardiovascular disease risk factors during a 3-year follow-up among 57 rotating shift workers and 29 day workers in industry. METHODS: We collected demographics by questionnaire, examined blood pressure, heart rate, pulse wave velocity, carotid media thickness, and maximal oxygen uptake. We assessed blood samples for determination of lipids, glycosylated hemoglobin, C-reactive protein, markers of inflammation, and particle concentrations/respirable dust. Baseline comparisons were analyzed using logistic regression (plaque) and linear regression for all other outcomes. We applied mixed models to assess differences in change in health outcomes between the shift workers and the day workers. RESULTS: At baseline, the adhesion molecules soluble vascular cell adhesion molecule 1 and soluble P-selectin were elevated among the shift workers compared with that of the day workers. There was a significant difference in change in pulse wave velocity between shift workers (1.29-m/s increase) and day workers (0.11-m/s increase) over the 3-year follow-up. Respirable dust levels were below the Norwegian occupational exposure limit. CONCLUSIONS: Shift work in industry is associated with arterial stiffening reflecting increased risk for future cardiovascular disease. More uncertainly, we found some support for systemic inflammation.

Low-voltage electrical accidents, immediate reactions and acute health care associated with self-reported general health 4 years later.

BACKGROUND AND AIMS: Electricians frequently experience low-voltage electrical accidents. Some such accidents involve long-term negative health consequences. Early identification of victims at risk for long-term injury may improve acute medical treatment and long-term follow-up. This study aimed to determine acute exposure, health effects and treatment associated with general health ≥ 2 years after low-voltage electrical accidents. METHODS: In a cross-sectional study, 89 male electricians who had experienced an electrical accident between 1994 and 2001 participated in a 2003 follow-up health examination. They were identified from a registry of low-voltage electrical accidents and included in the study. Based on exposure descriptions in the original accident reports, they were stratified into the following three groups: a current arc accident group (N = 34, mean age 38.8 years [standard deviation, SD = 12.2, range = 21-59]) and two groups with the passage of current through the body, either fixed to the current source ("no-let-go" group; N = 35, mean age 34.0 years [SD = 10.5, range = 21-57]) or not ("let-go" group; N = 20, mean age = 38.7 years [SD = 10.3, range = 21-63]). They retrospectively described acute reactions and assessed their current general health at the health examination. Multivariate linear regression, ordinal logistic regression and Fisher's exact test were used to compare acute reactions with health at follow-up in each exposure group. RESULTS: The multivariate analysis indicated that after accidents with the passage of current through the body, severe acute headache (ß = - 0.56, p = 0.013), years since the accident (ß = - 0.16, p = 0.017) and the accident being perceived as frightening (ß = - 0.48, p = 0.040) were negatively associated with general health ≥ 2 years later (R2 = 0.25, p = 0.002). If the exposure included a no-let-go experience, then acute severe body numbness (ß = - 0.53, p = 0.029) was also negatively associated with general health (R2 = 0.38, p = 0.002). Without such experience, only acute confusion (ß = - 0.90, p = 0.029) was negatively associated with the health at follow-up (R2 = 0.24, p = 0.029). In univariate analyses, after the passage of current through the body, acute dizziness (p = 0.029), apathy (p = 0.028), confusion (p = 0.007) and irregular heartbeat (p ≤ 0.05) were associated with poor long-term general health. The no-let-go group, more often than the let-go group, reported panic (p = 0.001), fear of death (p = 0.029), confusion (p = 0.014), exhaustion (p = 0.009), bodily numbness (p = 0.013) and immediate unconsciousness (p = 0.019). Acute symptoms beyond the first day after a current arc accident were associated with poor long-term general health (p = 0.015). DISCUSSION AND CONCLUSIONS: The acute reactions negatively associated with general health ≥ 2 years after low-voltage electrical accidents should alert the clinician in the acute phase after an electrical accident to the risk of developing negative long-term health effects. Future studies should specify long-term health beyond the concept of general health.

The COVID-19 Pandemic Decreases Cardiorespiratory Fitness: A 3-Year Follow-Up Study in Industry.

BACKGROUND: We aimed to determine if maximal oxygen uptake (V˙O2max), resting heart rate (RHR), and self-reported leisure- time moderate to vigorous physical activity (MVPA) changed over a 3-year follow-up (FU) among industrial workers. METHODS: We assessed cardiorespiratory fitness (CRF) August 2018 and August 2021. The last 17-18 months coincided with the COVID-19 pandemic. Data from 86 participants were collected; demographics by questionnaire and cardiovascular outcomes from medical examination: V˙O2max, RHR, and fat mass (%). Workers reported on their leisure-time MVPA twice. To assess changes in health outcomes we applied a linear mixed model, adjusting for baseline (BL) age, sex, pack-years, shift work, and a 5-month plant shutdown. Further, we adjusted for actual age instead of BL age. RESULTS: V˙O2max decreased from 39.6 mL/kg/min at BL to 34.0 at FU, a reduction of 5.6 mL/kg/min (95%CI, -7.6, -3.7). Adjusted for actual age, the corresponding figure for V˙O2max was 5.4 mL/kg/min, (95%CI, -7.4, -3.4), an annual loss of 4.6%. RHR increased from 61.3 to 64.4 beats per minute (95%CI, 0.8, 5.4). Self-reported MVPA decreased by 43.9 min/week, (95%CI, -73.5, -14.4). CONCLUSIONS: We observed a decrease in V˙O2max, an increase in RHR and a decrease in self-reported MVPA, suggesting physical inactivity during the COVID-19 pandemic.

Do regulatory tools instigate measures to prevent work-related psychosocial and ergonomic risk factors? A process evaluation of a Labour inspection authority trial in the Norwegian home-care services.

OBJECTIVE: There is a research gap regarding the way managers and employee representatives respond to Labour Authority interventions targeting work-related psychosocial and ergonomic risk factors. The present study aimed to determine if (I) labour inspections and (II) guidance-through-workshops led by inspectors were perceived by the target audience as equally useful and educational; and to determine if utility and enhanced knowledge were associated with the implementation of measures to prevent work-related risk factors. Finally, it aimed to determine if the managers in the intervention groups to a greater extent than the controls reported implementing such measures. RESULTS: Managers and employee representatives in both intervention groups reported a high level of perceived utility as well as a high level of enhanced knowledge. Both utility (p < 0.05) and enhanced knowledge (p < 0.05) were significantly associated with the implementation of, or plans to soon implement, measures to improve working conditions. When compared to controls, implemented measures, or plans to implement measures, were reported significantly more frequently by managers in the inspection group (p < 0.05). Trial Registration ClinicalTrials.gov ID: NCT03855163 Registered on February 26, 2019.

Effects of the Labour Inspectorate Authority's regulatory tools on psychosocial and biomechanical work factors in Norwegian home care services: a cluster randomised controlled trial.

OBJECTIVES: This study aimed to determine the effects of the Labour Inspectorate Authority's (LIA's) regulatory tools on psychosocial and biomechanical work factors in the Norwegian municipal home care services. METHODS: A cluster-randomised controlled trial conducted in the home care services with employee questionnaire data on work factors at baseline, and 6 and 12 months after the interventions. In total, 96 eligible municipalities were randomly assigned to either the control group or one of two interventions: (1) labour inspection visits, based on the LIA's standard inspections; and (2) guidance-through-workshops, where the participating services highlighted issues and trained labour inspectors provided guidance based on existing labour laws and regulations. RESULTS: No favourable intervention effect was observed for the inspection intervention. No effects were observed for most of the variables in the guidance intervention, although an effect was observed for the following psychosocial factors: decision control, control over work intensity and empowering leadership. However, after adjusting for multiple testing, none of the observed effects were statistically significant. CONCLUSION: Labour inspections did not affect psychosocial and biomechanical work factors in the home care services. A favourable effect of the guidance intervention on psychosocial work factors was observed. However, this was not evident after adjusting for multiple testing. Further research is needed to elaborate on how labour inspections and other regulatory tools can impact psychosocial and biomechanical work factors. TRIAL REGISTRATION NUMBER: NCT03855163.

A Cease in Shift Work Reverses Arterial Stiffness but Increases Weight and Glycosylated Hemoglobin A 5-Month Follow-Up in Industry.

BACKGROUND: Literature suggests an association between shift work and cardiovascular disease (CVD). Limited evidence is available on how a cessation of shift work affects CVD risk factors. AIM: We investigated whether a five-month plant shutdown affected CVD risk factors in 30 industrial shift workers. METHODS: We collected demographic data, self-reported data on physical activity (PA) and medical history by questionnaire. Pre- and post-plant shutdown, we measured blood pressure (BP), heart rate, lipids, glycosylated hemoglobin (HbA1c) and C-reactive protein (CRP). Additionally, we collected markers of inflammation, Matrix metalloproteinase-9 (MMP-9), Interleukin-6 (IL-6), Monocyte chemoattractant protein-1 (MCP-1), Tumor necrosis factor-alpha (TNF-α), P-selectin, Interleukin-1 beta (IL-1ß), and Interleukin-23 (IL-23). We also examined arterial stiffness (central blood pressure, augmentation pressure, and pulse wave velocity) by means of SphygmoCor® (AtCor Medical Pty Ltd., Sydney, Australia). We monitored sleep by actigraphy prior to and after plant shutdown, with additional registration of sleep quality and assessment of insomnia symptoms. RESULTS: After five months of plant shutdown, we found that HbA1c increased by 1.9 mmol/mol, weight by 1 kg and MCP-1 by 27.3 pg/mL, all unexpectedly. The other markers of inflammation did not change during shutdown, but CRP decreased close to significant levels. There were no changes in lipids during follow-up. Pulse-wave velocity (PWV) was reduced from 8.1 m/s (SD = 1.5) to 7.6 m/s (SD = 1.5), p = 0.03. The workers reported fewer signs of insomnia after shutdown. CONCLUSIONS: Our findings suggest that a five-month cessation in shift work increases weight and HbA1c, but also improves insomnia symptoms and reverses arterial stiffening.

Multiwalled Carbon Nanotubes Induce Fibrosis and Telomere Length Alterations.

Telomere shortening can result in cellular senescence and in increased level of genome instability, which are key events in numerous of cancer types. Despite this, few studies have focused on the effect of nanomaterial exposure on telomere length as a possible mechanism involved in nanomaterial-induced carcinogenesis. In this study, effects of exposure to multiwalled carbon nanotubes (MWCNT) on telomere length were investigated in mice exposed by intrapleural injection, as well as in human lung epithelial and mesothelial cell lines. In addition, cell cycle, apoptosis, and regulation of genes involved in DNA damage repair were assessed. Exposure to MWCNT led to severe fibrosis, infiltration of inflammatory cells in pleura, and mesothelial cell hyperplasia. These histological alterations were accompanied by deregulation of genes involved in fibrosis and immune cell recruitment, as well as a significant shortening of telomeres in the pleura and the lung. Assessment of key carcinogenic mechanisms in vitro confirmed that long-term exposure to the long MWCNT led to a prominent telomere shortening in epithelial cells, which coincided with G1-phase arrest and enhanced apoptosis. Altogether, our data show that telomere shortening resulting in cell cycle arrest and apoptosis may be an important mechanism in long MWCNT-induced inflammation and fibrosis.

Sleep Duration, Number of Awakenings and Arterial Stiffness in Industrial Shift Workers: A Five-Week Follow-Up Study.

Shift work may increase the risk for hypertension and arterial stiffness, potentially a consequence of disturbed sleep. The aim of this study was to investigate possible correlations between sleep length and spontaneous awakenings with selected cardiovascular risk factors in shift workers at an industrial plant. We examined 19 shift workers by means of blood pressure and arterial stiffness, measured as pulse wave velocity (PWV), prior to and after a 5-week shift period. Sleep patterns were monitored on a daily basis with the assistance of a smartphone-based sleep diary (the entire test period) and by actigraphy (limited to 2 weeks). The number of awakenings and total sleep time were calculated. Shorter sleep duration was associated with higher blood pressure and partly with higher PWV, indicating an increased risk of cardiovascular disease (CVD) with reduced sleep duration. Unexpectedly, a lower number of awakenings was associated with an increase in blood pressure, indicating a reduced risk of CVD. No other significant associations were determined. The results from the present study among shift workers in Norway could support the hypothesis that short sleep duration is associated with elevated blood pressure and arterial stiffness.

Long-Term Exposure to Nanosized TiO2 Triggers Stress Responses and Cell Death Pathways in Pulmonary Epithelial Cells.

There is little in vitro data available on long-term effects of TiO2 exposure. Such data are important for improving the understanding of underlying mechanisms of adverse health effects of TiO2. Here, we exposed pulmonary epithelial cells to two doses (0.96 and 1.92 µg/cm2) of TiO2 for 13 weeks and effects on cell cycle and cell death mechanisms, i.e., apoptosis and autophagy were determined after 4, 8 and 13 weeks of exposure. Changes in telomere length, cellular protein levels and lipid classes were also analyzed at 13 weeks of exposure. We observed that the TiO2 exposure increased the fraction of cells in G1-phase and reduced the fraction of cells in G2-phase, which was accompanied by an increase in the fraction of late apoptotic/necrotic cells. This corresponded with an induced expression of key apoptotic proteins i.e., BAD and BAX, and an accumulation of several lipid classes involved in cellular stress and apoptosis. These findings were further supported by quantitative proteome profiling data showing an increase in proteins involved in cell stress and genomic maintenance pathways following TiO2 exposure. Altogether, we suggest that cell stress response and cell death pathways may be important molecular events in long-term health effects of TiO2.

Adverse social behaviour at the workplace and subsequent physician certified sick leave: a three-wave prospective study of the general working population in Norway.

OBJECTIVES: We aimed to provide an integrated picture of the relationship between different facets of adverse social behaviour (ASB) at the workplace and sick leave. METHODS: Data from a randomly drawn prospective cohort of the general working population. Eligible respondents were interviewed in 2009, 2013 or 2016, and were registered with an employee relationship of at least 50 working days in the national register the year following the survey interviews (n=21 674 observations/13 470 respondents). We investigated the prospective associations of self-reported exposure to ASB, including threats/acts of violence, bullying and sexual harassment, with physician-certified sick leave of 1-16 days (ie, low level of sick leave (LLSL)) and >16 days (ie, high level of sick leave (HLSL)) by means of mixed effects logistic regression. RESULTS: The prevalence of sick leave was 18.4% (n=3986 observations) for LLSL and 16.1% (n=3492 observations) for HLSL. The different facets of ASB were independently associated with higher odds of sick leave, with stronger associations for HLSL than for LLSL. Adjusted for sex, age, education level, occupation, previous sickness absence level, OR (95% CI) for HLSL was 1.97 (1.61 to 2.35) for threats/acts of violence, 1.97 (1.53 to 2.54) for bullying and 1.41 (1.10 to 1.79) for sexual harassment. The population risks of LLSL and HLSL attributable to ASB were 5.27 (95% CI 1.85 to 8.81) and 8.27% (95% CI 4.01 to 12.48), respectively. CONCLUSIONS: Threats/acts of violence, bullying and sexual harassment were all independent predictors of sick leave, with threats/acts of violence appearing as the single most important factor.

Pro-Inflammatory Role of AQP4 in Mice Subjected to Intrastriatal Injections of the Parkinsonogenic Toxin MPP.

Aquaporin-4 (AQP4) is critically involved in brain water and volume homeostasis and has been implicated in a wide range of pathological conditions. Notably, evidence has been accrued to suggest that AQP4 plays a proinflammatory role by promoting release of astrocytic cytokines that activate microglia and other astrocytes. Neuroinflammation is a hallmark of Parkinson's disease (PD), and we have previously shown that astrocytes in substantia nigra (SN) are enriched in AQP4 relative to cortical astrocytes, and that their complement of AQP4 is further increased following treatment with the parkinsonogenic toxin MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine). Here, we investigated the effect of Aqp4 deletion on microglial activation in mice subjected to unilateral intrastriatal injection of 1-methyl-4-phenylpyridinium (MPP+, the toxic metabolite of MPTP). Our results show that MPP+ injections lead to a pronounced increase in the expression level of microglial activating genes in the ventral mesencephalon of wild type (WT) mice, but not Aqp4-/- mice. We also show, in WT mice, that MPP+ injections cause an upregulation of nigral AQP4 and swelling of astrocytic endfeet. These findings are consistent with the idea that AQP4 plays a pro-inflammatory role in Parkinson's disease, secondary to the dysregulation of astrocytic volume homeostasis.

Occupational Noise Exposure and Vestibular Schwannoma: A Case-Control Study in Sweden.

It has been suggested that the association between self-reported occupational noise exposure and vestibular schwannoma (VS), found in several studies, represents recall bias. Therefore, we aimed to study the relationship in a large case-control study using occupational noise measurements. We performed a case-control study using data from Sweden for 1,913 VS cases diagnosed in 1961-2009 and 9,566 age- and sex-matched population controls. We defined occupational history by linkage to national censuses from 1960, 1970, 1980, and 1990. We estimated occupational noise exposure for each case and control using a job-exposure matrix. There was no association between occupational noise exposure and VS. Among subjects assessed as ever exposed to occupational noise levels of ≥85 dB (214 cases and 1,142 controls), the odds ratio for VS per 5 years of exposure was 1.02 (95% confidence interval: 0.90, 1.17). Workers with noise levels of ≥85 dB for at least 15 years (5-year latency period), showed no increased risk of VS (odds ratio = 0.98, 95% confidence interval: 0.73, 1.31) compared with those who had never been exposed to noise levels of 75 dB or higher. In summary, our large study does not support an association between occupational noise exposure and VS.

Conventional versus ultrasound treat to target: no difference in magnetic resonance imaging inflammation or joint damage over 2 years in early rheumatoid arthritis.

OBJECTIVE: To investigate whether an ultrasound-guided treat-to-target strategy for early RA would lead to reduced MRI inflammation or less structural damage progression compared with a conventional treat-to-target strategy. METHODS: A total of 230 DMARD-naïve early RA patients were randomized to an ultrasound tight control strategy targeting DAS <1.6, no swollen joints and no power Doppler signal in any joint or a conventional strategy targeting DAS <1.6 and no swollen joints. Patients in both arms were treated according to the same DMARD escalation strategy. MRI of the dominant hand was performed at six time points over 2 years and scored according to the OMERACT RA MRI scoring system. A total of 218 patients had baseline and one or more follow-up MRIs and were included in the analysis. The mean MRI score change from baseline to each follow-up and the 2 year risk for erosive progression were compared between arms. RESULTS: MRI bone marrow oedema, synovitis and tenosynovitis improved over the first year and was sustained during the second year of follow-up, with no statistically significant differences between the ultrasound and the conventional arms at any time point. The 2 year risk for progression of MRI erosions was similar in both treatment arms: ultrasound arm 39%, conventional arm 33% [relative risk 1.16 (95% CI 0.81, 1.66), P = 0.40]. CONCLUSION: Incorporating ultrasound information in treatment decisions did not lead to reduced MRI inflammation or less structural damage compared with a conventional treatment strategy. The findings support that systematic use of ultrasound does not provide a benefit in the follow-up of patients with early RA. TRIAL REGISTRATION NUMBER: Clinicaltrials.gov, http://clinicaltrials.gov, NCT01205854.