Isabelle Thaon

Twelve-year longitudinal study of respiratory status in dairy farmers.

To evaluate respiratory risk in dairy farmers, the present authors conducted a longitudinal study in the Doubs region of France. From a cohort constituted in 1986 (T1), 157 (62.8%) dairy farmers and 159 (63.6%) controls were re-evaluated in 1998 (T3). The study protocol comprised a medical and occupational questionnaire, spirometric tests at both evaluations, and noninvasive measure of blood oxygen saturation with pulse oximetry (Sp,O2) at T3. In 1998, the prevalence of chronic bronchitis was higher in dairy farmers. In cross-sectional analyses, all respiratory function parameters and Sp,O2 were significantly lower in dairy farmers. In a multiple linear regression model, farming, age, male sex and smoking were significantly and negatively correlated with Sp,O2. However, the mean annual decline in respiratory function parameters did not differ significantly between groups. After adjustment of covariables, accelerated decline in vital capacity and forced expiratory volume in one second was associated with age, smoking and male sex. Decline in vital capacity was accelerated in dairy farmers working in traditional farms and those currently foddering. The current study demonstrates that dairy farming is associated with an increased risk of lung disorders and a decrease in blood oxygen saturation and suggests that respiratory function impairment is correlated with cumulated exposure to organic dusts.

Predictive risk factors for chronic regional and multisite musculoskeletal pain: A 5-year prospective study in a working population

Summary Physical and psychological work‐related factors pertaining to the 5‐year incidence of multiple body sites musculoskeletal pain (MSP) may be gender specific. In particular, psychological factors seem to be predictive of onset of MSP, but only in women. Only the physical work factor (ie, forceful effort constraints) was an important robust predictor of multisite MSP, but only in men. ABSTRACT The role of psychosocial and physical factors in the development of musculoskeletal pain (MSP) has now been clearly demonstrated. However, it is unclear whether these factors contribute to specific regional MSP or to multisite pain. The main goal of this study was to assess the impact of work‐related factors according to gender on the development of regional and multisite MSP. A total of 12,591 subjects (65% men and 35% women) who were born in 1938, 1943, 1948, and 1953 and were participating in a French longitudinal prospective epidemiological survey (ESTEV) in 1990 to 1995 were eligible. Personal factors and work exposure were assessed by self‐administered questionnaires. Statistical associations between chronic MSP (regional body site or multisite), personal factors, and occupational factors were analyzed using logistic regression modeling. The incidence of regional MSP and multisite pain in 1995 were, respectively, 17% and 25.6%. For women, highly repetitive movements predicted neck/shoulder pain; posture and vibrations predicted arm and low back pain; and effort with tools predicted arm pain. For men, forceful effort and vibrations predicted neck/shoulder pain; posture and forceful effort predicted lower limb and low back pain; and forceful effort and effort with tools predicted arm pain. Physical constraints (ie, forceful effort or vibrations) were associated with multisite pain in both genders. Only for women, psychological factors were risk factors predictive of upper limb pain and in 3 or 4 painful anatomical sites. These results support the hypothesis that some physical and psychological work‐related factors are predictive of regional or multisite MSP but differ according to gender. Gender differences and risk factors for work‐related musculoskeletal pain should be also taken into account to more effectively target preventive measures.

Long-term occupational consequences of asthma in a large French cohort of male workers followed up for 5 years

OBJECTIVES The aim of this study was to describe the long-term occupational consequences of asthma in males of the ESTEV study, a French longitudinal cohort of working subjects aged 37-52 at inclusion. METHODS Medical data, self-perceived health status, sick leave, occupational social class and employment characteristics were recorded twice by occupational physicians in 1990 (12,233 subjects) and 1995 (10,608 subjects). Asthma was characterized as to its onset (childhood, i.e., before age 20 vs. adult) and to its past versus current status by the physician. RESULTS Of the 398 asthmatics, the onset was before age 20 for 226 and the asthma status was classified as current for 159 subjects. Unemployment was not higher before baseline or during follow-up, in asthmatics as compared to non-asthmatics, despite a significantly higher prevalence of sick leave in the previous year among current asthmatics (38.4% vs. 27.0%, P = 0.005). Being a blue collar worker in 1990 is negatively related to childhood asthma but not to the current asthma status. In 1995, current adult-onset asthmatics had stopped working due to disability more frequently than never-asthmatics. CONCLUSION Our findings suggest that the major consequence of asthma on employment status is a selective exclusion, observed in childhood asthmatics at the beginning of their working life and in current adult-onset asthmatics at the end of their working life. Past unemployment was shown not to be higher in working asthmatics.

Factors Influencing the Microbial Composition of Metalworking Fluids and Potential Implications for Machine Operator's Lung

ABSTRACT Hypersensitivity pneumonitis, also known as “machine operators lung” (MOL), has been related to microorganisms growing in metalworking fluids (MWFs), especially Mycobacterium immunogenum. We aimed to (i) describe the microbiological contamination of MWFs and (ii) look for chemical, physical, and environmental parameters associated with variations in microbiological profiles. We microbiologically analyzed 180 MWF samples from nonautomotive plants (e.g., screw-machining or metal-cutting plants) in the Franche-Comté region in eastern France and 165 samples from three French automotive plants in which cases of MOL had been proven. Our results revealed two types of microbial biomes: the first was from the nonautomotive industry, showed predominantly Gram-negative rods (GNR), and was associated with a low risk of MOL, and the second came from the automotive industry that was affected by cases of MOL and showed predominantly Gram-positive rods (GPR). Traces of M. immunogenum were sporadically detected in the first type, while it was highly prevalent in the automotive sector, with up to 38% of samples testing positive. The use of chromium, nickel, or iron was associated with growth of Gram-negative rods; conversely, growth of Gram-positive rods was associated with the absence of these metals. Synthetic MWFs were more frequently sterile than emulsions. Vegetable oil-based emulsions were associated with GNR, while mineral ones were associated with GPR. Our results suggest that metal types and the nature of MWF play a part in MWF contamination, and this work shall be followed by further in vitro simulation experiments on the kinetics of microbial populations, focusing on the phenomena of inhibition and synergy.

Immuno-reactive proteins from Mycobacterium immunogenum useful for serodiagnosis of metalworking fluid hypersensitivity pneumonitis

Metalworking fluid-associated hypersensitivity pneumonitis (MWF-HP) is a pulmonary disease caused by inhaling microorganisms present in the metalworking fluids used in the industrial sector. Mycobacterium immunogenum is the main etiological agent. Among the clinical, radiological and biological tools used for diagnosis, serological tests are important. The aim of this study was to identify immunogenic proteins in M. immunogenum and to use recombinant antigens for serological diagnosis of MWF-HP. Immunogenic proteins were detected by two-dimensional Western blot and candidate proteins were identified by mass spectrometry. Recombinant antigens were expressed in Escherichia coli and tested by enzyme-linked immunosorbent assay (ELISA) with the sera of 14 subjects with MWF-HP and 12 asymptomatic controls exposed to M. immunogenum. From the 350 spots visualized by two-dimensional gel electrophoresis with M. immunogenum extract, 6 immunogenic proteins were selected to be expressed as recombinant antigens. Acyl-CoA dehydrogenase antigen allowed for the best discrimination of MWF-HP cases against controls with an area under the receiver operating characteristics (ROC) curve of 0.930 (95% CI=0.820-1), a sensitivity of 100% and a specificity of 83% for the optimum threshold. Other recombinant antigens correspond to acyl-CoA dehydrogenase FadE, cytosol aminopeptidase, dihydrolipoyl dehydrogenase, serine hydroxymethyltransferase and superoxide dismutase. This is the first time that recombinant antigens have been used for the serodiagnosis of hypersensitivity pneumonitis. The availability of recombinant antigens makes it possible to develop standardized serological tests which in turn could simplify diagnosis, thus making it less invasive.

Impact of farm modernity on the prevalence of chronic obstructive pulmonary disease in dairy farmers

Dairy farming is associated with an excess of chronic obstructive pulmonary disease (COPD). The dairy industry has been changing for the past three decades with larger, more efficient farms and potentially less exposure to agents involved in COPD development. However, the impact of farm modernisation on COPD prevalence is unknown. We studied respiratory symptoms, respiratory function by spirometry and tobacco smoking in 575 male dairy farmers working either in traditional or in modern farms in the French Doubs region. COPD was defined by the Global Initiative for Chronic Obstructive Lung Disease (GOLD) criterion (forced expiratory volume in 1 s/forced vital capacity (FEV1/FVC) <0.70) and by the Quanjer reference equation (FEV1/FVC<lower limit of normal (LLN)). Modern farms were defined either as having a separation between the house and the cowshed (model 1) or as having a loose housing system for the animals (model 2). The prevalence of COPD in dairy farmers was 12.0±2.7% (GOLD), and 5.6±4.1% (LLN definition). By multivariate analysis using the LLN definition, tobacco smoking (OR (95% CI) 3.96 (1.53 to 10.3) and 3.42 (1.32 to 8.84) for models 1 and 2, respectively) and characteristics of traditional farms (1.97 (1.02 to 4.47) and 5.20 (1.73 to 15.64) for models 1 and 2, respectively) were associated with higher COPD prevalence. Working in a traditional farm plus current smoking had an additive effect on COPD prevalence in model 1 and a synergistic effect in model 2. These findings support a positive impact of farm modernity on COPD prevalence in dairy farmers. Occupational and smoking-related risk factors are of nearly the same magnitude.

Increased Lung Function Decline in Blue-collar Workers Exposed to Welding Fumes

BACKGROUND There is no consensus at the present time about the effect of welding on lung function decline. This study compared lung function decline between blue-collar workers exposed and not exposed to welding fumes in a French longitudinal cohort of 21,238 subjects aged 37 to 52 years at inclusion. METHODS Medical data, occupation, sector of activity, and spirometry were recorded twice by occupational physicians in 1990 and 1995. A job-exposure matrix was used to identify 503 male blue-collar workers exposed to welding fumes and 709 control subjects and to define the weekly duration of exposure to welding fumes. RESULTS Baseline lung function parameters were higher in workers exposed to welding fumes than in control subjects. After a 5-year follow-up, welding-fume exposure was associated with a nonsignificant decline in FVC (P = .06) and FEV(1) (P = .07) after adjustment for age, pack-years, BMI, and baseline value of the parameter. A significant accelerated decline in FEV(1) (P = .046) was also observed in never smokers exposed to welding fumes. An “exposure-response” relationship was observed between FEV(1) decline and weekly duration of exposure to welding fumes in nonsmokers but not in smokers. CONCLUSIONS Blue-collar workers exposed to welding fumes showed accelerated decline in lung function, which, in nonsmokers, was related to weekly duration of exposure.

Negative impact of rurality on lung cancer survival in a population-based study.

Introduction: Several studies have suggested that rurality is a risk factor for worse prognosis in cancer. Methods: The study population included the 2268 lung cancer cases collected between 1981 and 1996 in the Doubs Cancer Registry (France). Results: The numbers of patients were 849 (31.8%) in rural areas and 89 (3.3%) in very rural areas. The relative 5-year survival was 15.2% in rural areas and 13.4% in urban areas (p = 0.5), and 2.7% in very rural areas and 14.4% in extended urban areas (p = 0.02). Multivariate analyses of observed and relative survival showed that patients living in very rural areas (p < 0.0001), 65 years of age and older and having small cell carcinoma had a significantly shorter survival. Conclusions: This study showed that the multidimensional definition of rurality identified a population with unfavorable prognoses.

Predictors of early cessation of dairy farming in the French Doubs province: 12-year follow-up†

BACKGROUND A healthy worker effect due to respiratory disability has been noted in the farming population, but other factors may also interfere. Little has been published about factors influencing the early cessation of work in self-employed dairy farmers. METHODS Two hundred and nineteen dairy farmers were included from a cohort constituted in eastern France in 1993-1994 with a 12-year follow-up. Spirometric data, personal, and farm characteristics were registered. Cox models with delayed entry in which age was the time-scale were applied to identify the baseline predictive factors of the early cessation of dairy farming. RESULTS Working in a modern farm was protective against early cessation of dairy farming (hazard ratio: 0.36 [95% CI: 0.16-0.81]), especially in men. Having asthma was a predictive factor of early cessation, especially in women (hazard ratio: 16.12 [95% CI: 3.28-79.12]). CONCLUSIONS The most predictive factors of early cessation of dairy farming were health related in women and farm related in men.

Anxious and depressive symptoms in the French Asbestos-Related Diseases Cohort: risk factors and self-perception of risk.

Background Asbestos is known to be an independent risk factor for lung and pleural cancers. However, to date, little attention has been paid to the psychological effects of asbestos exposure among exposed subjects. The objectives of this study were to estimate the prevalence of anxious and depressive symptoms among >2000 French participants of the Asbestos-Related Diseases Cohort (ARDCO), 6 years after their inclusion, to identify the risk factors associated with those anxious and depressive symptoms and to evaluate the impact of the asbestos-risk perception. Methods The ARDCO was constituted in four regions of France between October 2003 and December 2005, by including former asbestos workers. Between 2011 and 2012, participants of the ARDCO program were invited to undergo another chest CT scan 6 years after the previous scan. Participants were asked to complete questionnaires including asbestos exposure assessment, Hospital Anxiety and Depression Scale (HADS), asbestos-risk perception and self-perception of asbestos-related diseases. Results Among the 2225 participants, 2210 fully completed questionnaires were collected and analyzed. The prevalence of symptoms of probable anxiety and probable depression was 19.7% and 9.9%, respectively. The risk of anxious and depressive symptoms was independently associated with self-perception of the intensity of asbestos exposure, asbestos-risk perception and self-perception of asbestos-related diseases. Conclusion The results obtained in this large study confirm that previously asbestos-exposed subjects are likely to develop anxious and depressive symptoms. Finally, implications related to the prevention of anxiety and depression among asbestos-exposed workers is discussed.