Should systemic sclerosis be recognised as an occupational disease in Switzerland?

Systemic sclerosis is a rare autoimmune disease characterised by a multifactorial aetiology involving a gene–environment interaction. Despite the growing epidemiological arguments for odds ratio (OR) data showing an association with occupational exposure, systemic sclerosis is not currently included in the list of recognised occupational diseases in Switzerland, unlike other northern European countries. Future recognition will be conditional on the demonstration of a strong association between the disease and occupational exposure in the scientific literature. The present article’s main goal is to present five cases of systemic sclerosis investigated for possible occupational aetiologies during occupational pathology consultations at the Institute for Work and Health, in Lausanne. The occupational aetiologies of these cases are discussed against the background of a literature review of publications from the past 20 years in order to determine whether recognition as an occupational disease is possible within Switzerland’s legal framework. Epidemiological studies of systemic sclerosis have identified strong associations with occupational factors such as exposure to silica and solvents, with ORs >2, and weaker associations with epoxy resins and welding fumes. Other occupational exposures are also known to induce systemic sclerosis-like diseases, such as vinyl chloride disease and toxic oil syndrome. All five patients had been exposed to either silica, solvents, or both. Given their exposure and the data in the literature, four patients had their cases declared to their accident insurance companies and two of them were recognised as suffering from an occupational disease by the Swiss National Accident Insurance Fund. Our literature review enabled us to design a short questionnaire to help general practitioners and rheumatologists to identify those patients with systemic sclerosis who are likely to have their illness recognised as an occupational disease.

Biological monitoring of workers exposed to carcinogens using the buccal micronucleus approach: A systematic review and meta-analysis.

A biomarker-based approach using micronucleus (MN) (extranuclear DNA-containing bodies) frequencies in buccal cells has been proposed to monitor workers exposed to aero-digestive carcinogens for early detection of occupational cancer. To assess this non-invasive MN approach, we sought to understand: (A) What is the extent of MN frequency increase in occupationally exposed over non-exposed populations across studies published in the scientific literature for buccal cells; and (B) Which types of occupational exposures give relevant summary MN ratios across studies published in the scientific literature. A systematic literature review was performed, and the MN frequency ratios for buccal cells were calculated for each occupational study. Meta-analytic techniques were applied using the confidence interval or a standard error on the log-transformed ratio. Exposure categories were developed based on similar occupational exposures or jobs. A summary ratio and proportion of variance explained (the I2 index) were derived assuming a Gaussian random effect model for each exposure category. The meta-analysis of the published literature (n = 96 studies) showed large random variability between studies within each category (I2 > 90%), except where exposures were to a single carcinogenic substance (e.g. formaldehyde, silica) or similar jobs were performed (e.g. antineoplastic dispensing, gasoline attendants). The greatest summary frequency ratios were for silica (FR 9.02 95%CI 6.83-11.93), formaldehyde (FR 4.81 95%CI 2.19-10.60), and for hairdressers as an exposure category (FR 7.06 95%CI 3.96-12.57). The unexplained between-study variability can be related to exposures to mixtures of carcinogens with unknown mechanisms. If the latter had been measured, the between-study variability may have been explained. We conclude that better exposure assessments are needed to understand the relationship between occupational exposures and MN frequency responses in buccal cells. Nevertheless, our analysis indicates that the buccal cell MN assay is a promising tool for surveying workers exposed to genotoxic agents.

Predictors of Return to Work 12 Months After Solid Organ Transplantation: Results from the Swiss Transplant Cohort Study.

Background Return to work with or after a chronic disease is not a very well understood process, influenced by a variety of personal, professional, societal and medical factors. The aim of this study is to identify predictors for return to work 12 months after a solid organ transplant applying a bio-psycho-social model. Methods This study is based on patients included in the Swiss Transplant Cohort Study, a national prospective multicentre cohort, who underwent a first solid organ transplant (kidney, liver, heart, lung). Bio-psycho-social factors were tested and predictors of return to work identified using logistic regression models. Results Among the 636 patients included in the study, 49.8% (317) were employed 12 months post-transplant. The major predictor for returning to work 12 months posttransplant was pre-transplant employment status (OR 10.8). Accordingly, the population was stratified in employed and not employed pre-transplant groups. Age, self-perceived health (6 months post-transplant) and the transplanted organ were significantly associated with post-transplant employment status in both groups. Return to work was influenced by education, depression (6 month post-transplant) and waiting time in the employed pre-transplant group and by invalidity pension in the not employed pre-transplant group. Conclusion Employment status pre-transplant being highly associated with employment status post-transplant, the process promoting return to work should be started well before surgery. Biomedical, psychological and social factors must be taken into account to promote return to work in transplanted patients.

Respiratory health of dust-exposed Congolese coltan miners.

PURPOSE: In Democratic Republic of the Congo (DRC), informal coltan mining has been expanding amidst increased insecurity due to armed conflicts. We investigated the impact of occupational dust-exposure on the respiratory health of Congolese coltan miners. METHODS: In total, 441 Congolese workers participated in this study, including 199 informal coltan miners and 242 office workers (controls). Information on respiratory complaints was collected using two standardized questionnaires. Physical examination (vital signs, auscultation) and lung function test (Peak Flow meter) were performed. In addition, workplace airborne PM2.5 and volatile organic compounds (VOC) concentrations were measured. RESULTS: Higher airborne PM2.5 (range 180-210 µg/m3) and VOC (range 1.4-2.3 µg/m3) levels were detected at coltan mining work stations as compared with control sites (19-44 and 0.5-0.8 µg/m3, respectively). All respiratory complaints and disorders were more prevalent in informal coltan miners than in controls. Additionally, a markedly lower mean PEFR was observed in coltan miners than in controls (347.93 ± 6.88 vs. 493.23 ± 67.38 L/min, respectively). Moreover, positive associations between informal coltan mining and almost all respiratory complaints were observed, except wheezing at effort and night cough. On the other hand, an inverse association was observed between lung function (PEFR) and PM2.5 exposure, between PEFR and VOC exposure, and also between PEFR and current smoking. CONCLUSIONS: This study showed high prevalence of respiratory complaints in Congolese informal coltan miners, suggesting the necessity to implement efficient occupational safety measures and regulate this informal mining business.

Employment 12 months after kidney transplantation: An in-depth bio-psycho-social analysis of the Swiss Transplant Cohort.

BACKGROUND: Return to work with or after a chronic disease is a dynamic process influenced by a variety of interactions between personal, work, societal and medical resources or constraints. The aim of this study was to identify predictors for employment 12 months after transplantation in kidney patients, applying a bio-psycho-social model. METHODS: All kidney patients followed in the Swiss Transplant Cohort between May 2008 and December 2012, aged 18 to 65 were assessed before, 6 and 12 months after transplantation. RESULTS: Of the 689 included patients, 56.2% worked 12 months post- transplantation compared to 58.9% pre-transplantation. Age, education, self-perceived health (6 months post- transplantation), pre- transplantation employment and receiving an organ from a living donor are significant predictors of employment post- transplantation. Moreover, while self-perceived health increased post- transplantation, depression score decreased only among those employed 12 months post- transplantation. Pre- transplantation employment status was the main predictor for post- transplantation employment (OR = 18.6) and was associated with sex, age, education, depression and duration of dialysis. An organ from a living donor (42.1%) was more frequent in younger patients, with higher education, no diabetes and shorter waiting time to surgery. CONCLUSION: Transplantation did not increase employment in end-stage kidney disease patients but helped maintaining employment. Pre-transplantation employment has been confirmed to be the most important predictor of post-transplantation employment. Furthermore, socio-demographic and individual factors predicted directly and indirectly the post-transplantation employment status. With living donor, an additional predictor linked to social factors and the medical procedure has been identified.

DNA Damage among Wood Workers Assessed with the Comet Assay.

Exposure to wood dust, a human carcinogen, is common in wood-related industries, and millions of workers are occupationally exposed to wood dust worldwide. The comet assay is a rapid, simple, and sensitive method for determining DNA damage. The objective of this study was to investigate the DNA damage associated with occupational exposure to wood dust using the comet assay (peripheral blood samples) among nonsmoking wood workers (n = 31, furniture and construction workers) and controls (n = 19). DNA damage was greater in the group exposed to composite wood products compared to the group exposed to natural woods and controls (P < 0.001). No difference in DNA damage was observed between workers exposed to natural woods and controls (P = 0.13). Duration of exposure and current dust concentrations had no effect on DNA damage. In future studies, workers' exposures should include cumulative dust concentrations and exposures originating from the binders used in composite wood products.

Increase in oxidative stress levels following welding fume inhalation: a controlled human exposure study.

BACKGROUND: Tungsten inert gas (TIG) welding represents one of the most widely used metal joining processes in industry. It has been shown to generate a large majority of particles at the nanoscale and to have low mass emission rates when compared to other types of welding. Despite evidence that TIG fume particles may produce reactive oxygen species (ROS), limited data is available for the time course changes of particle-associated oxidative stress in exposed TIG welders. METHODS: Twenty non-smoking male welding apprentices were exposed to TIG welding fumes for 60 min under controlled, well-ventilated settings. Exhaled breathe condensate (EBC), blood and urine were collected before exposure, immediately after exposure, 1 h and 3 h post exposure. Volunteers participated in a control day to account for oxidative stress fluctuations due to circadian rhythm. Biological liquids were assessed for total reducing capacity, hydrogen peroxide (H2O2), malondialdehyde (MDA), and 8-hydroxy-2'-deoxyguanosine (8-OHdG) concentrations at each time point. A linear mixed model was used to assess within day and between day differences. RESULTS: Significant increases in the measured biomarkers were found at 3 h post exposure. At 3 h post exposure, we found a 24 % increase in plasma-H2O2 concentrations ([95%CI: 4 % to 46 %], p = 0.01); a 91 % increase in urinary-H2O2 ([2 % to 258 %], p = 0.04); a 14 % increase in plasma-8-OHdG ([0 % to 31 %], p = 0.049); and a 45 % increase in urinary-8-OHdG ([3 % to 105 %], p = 0.03). Doubling particle number concentration (PNC) exposure was associated with a 22 % increase of plasma-8-OHdG at 3 h post exposure (p = 0.01). CONCLUSION: A 60-min exposure to TIG welding fume in a controlled, well-ventilated setting induced acute oxidative stress at 3 h post exposure in healthy, non-smoking apprentice welders not chronically exposed to welding fumes. As mass concentration of TIG welding fume particles is very low when compared to other types of welding, it is recommended that additional exposure metrics such as PNC are considered for occupational risk assessments. Our findings highlight the importance of increasing awareness of TIG welding fume toxicity, especially given the realities of welding workplaces that may lack ventilation; and beliefs among interviewed welders that TIG represents a cleaner and safer welding process.

Associations of short-term particle and noise exposures with markers of cardiovascular and respiratory health among highway maintenance workers.

BACKGROUND: Highway maintenance workers are constantly and simultaneously exposed to traffic-related particle and noise emissions, both of which have been linked to increased cardiovascular morbidity and mortality in population-based epidemiology studies. OBJECTIVES: We aimed to investigate short-term health effects related to particle and noise exposure. METHODS: We monitored 18 maintenance workers, during as many as five 24-hr periods from a total of 50 observation days. We measured their exposure to fine particulate matter (diameter ≤ 2.5 µm; PM2.5), ultrafine particles, and noise, and the cardiopulmonary health end points: blood pressure, proinflammatory and prothrombotic markers in the blood, lung function, and fractional exhaled nitric oxide (FeNO) measured approximately 15 hr after work. Heart rate variability was assessed during a sleep period approximately 10 hr after work. RESULTS: PM2.5 exposure was significantly associated with C-reactive protein and serum amyloid A, and was negatively associated with tumor necrosis factor α. None of the particle metrics were significantly associated with von Willebrand factor or tissue factor expression. PM2.5 and work noise were associated with markers of increased heart rate variability, and with increased high-frequency and low-frequency power. Systolic and diastolic blood pressure on the following morning were significantly associated with noise exposure after work, and nonsignificantly associated with PM2.5. We observed no significant associations between any of the exposures and lung function or FeNO. CONCLUSIONS: Our findings suggest that exposure to particles and noise during highway maintenance work might pose a cardiovascular health risk. Actions to reduce these exposures could lead to better health for this population of workers.

Workers exposed to wood dust have an increased micronucleus frequency in nasal and buccal cells: results from a pilot study.

Wood dust is recognised as a human carcinogen, based on the strong association of wood dust exposure and the elevated risk of malignant tumours of the nasal cavity and paranasal sinuses [sino-nasal cancer (SNC)]. The study aimed to assess genetic damage in workers exposed to wood dust using biomarkers in both buccal and nasal cells that reflect genome instability events, cellular proliferation and cell death frequencies. Nasal and buccal epithelial cells were collected from 31 parquet layers, installers, carpenters and furniture workers (exposed group) and 19 non-exposed workers located in Switzerland. Micronucleus (MN) frequencies were scored in nasal and buccal cells collected among woodworkers. Other nuclear anomalies in buccal cells were measured through the use of the buccal micronucleus cytome assay. MN frequencies in nasal and buccal cells were significantly higher in the exposed group compared to the non-exposed group; odds ratio for nasal cells 3.1 [95% confidence interval (CI) 1.8-5.1] and buccal cells 1.8 (95% CI 1.3-2.4). The exposed group had higher frequencies of cells with nuclear buds, karyorrhectic, pyknotic, karyolytic cells and a decrease in the frequency of basal, binucleated and condensed cells compared to the non-exposed group. Our study confirms that woodworkers have an elevated risk for chromosomal instability in cells of the aerodigestive tract. The MN assay in nasal cells may become a relevant biomonitoring tool in the future for early detection of SNC risk. Future studies should seek to standardise the protocol for MN frequency in nasal cells similar to that for MN in buccal cells.

Generation of polycyclic aromatic hydrocarbons (PAHs) during woodworking operations.

Occupational exposures to wood dust have been associated with an elevated risk of sinonasal cancer (SNC). Wood dust is recognized as a human carcinogen but the specific cancer causative agent remains unknown. One possible explanation is a co-exposure to; wood dust and polycyclic aromatic hydrocarbons (PAHs). PAHs could be generated during incomplete combustion of wood due to heat created by use of power tools. To determine if PAHs are generated from wood during common wood working operations, PAH concentrations in wood dust samples collected in an experimental chamber operated under controlled conditions were analyzed. In addition, personal air samples from workers exposed to wood dust (n = 30) were collected. Wood dust was generated using three different power tools: vibrating sander, belt sander, and saw; and six wood materials: fir, Medium Density Fiberboard (MDF), beech, mahogany, oak and wood melamine. Monitoring of wood workers was carried out by means of personal sampler device during wood working operations. We measured 21 PAH concentrations in wood dust samples by capillary gas chromatography-ion trap mass spectrometry (GC-MS). Total PAH concentrations in wood dust varied greatly (0.24-7.95 ppm) with the lowest being in MDF dust and the highest in wood melamine dust. Personal PAH exposures were between 37.5-119.8 ng m(-3) during wood working operations. Our results suggest that PAH exposures are present during woodworking operations and hence could play a role in the mechanism of cancer induction related to wood dust exposure.

[Effects of shift work on health]. / Effets du travail de nuit sur la santé.

20% of employees in industrialized countries are concerned by shift work. Nevertheless, there is very little information in general medical journals about the effects of shift work on health. Shift work can have several major effects on health such as cardiovascular and digestive disorders among others, as demonstrated by several studies in recent decades. Shift work has attracted considerable attention recently when it was declared probable carcinogen by the International Agency for research on cancer. We review the health disorders that may be generated or aggravated by shift work and illustrate the problem by two case studies of occupational medicine and discuss the appropriate attitude to take.

Chronic obstructive pulmonary disease in never-smoking animal farmers working inside confinement buildings.

BACKGROUND: In animal farming, respiratory disease has been associated with indoor air contaminants and an excess in FEV1 decline. Our aim was to determine the characteristics and risk factors for chronic obstructive pulmonary disease (COPD) in never-smoking European farmers working inside animal confinement buildings. METHODS: A sample of participants in the European Farmers' Study was selected for a cross-sectional study assessing lung function and air contaminants. Dose-response relationships were assessed using logistic regression models. RESULTS: COPD was found in 18 of 105 farmers (45.1 SD 11.7 years) (17.1%); 8 cases (7.6%) with moderate and 3 cases (2.9%) with severe disease. Dust and endotoxin showed a dose-response relationship with COPD, with the highest prevalence of COPD in subjects with high dust (low=7.9%/high=31.6%) and endotoxin exposure (low=10.5%/high=20.0%). This association was statistically significant for dust in the multivariate analysis (OR 6.60, 95% CI 1.10-39.54). CONCLUSION: COPD in never-smoking animal farmers working inside confinement buildings is related to indoor dust exposure and may become severe.