Co-exposure to refractory ceramic fibres and asbestos and risk of pleural mesothelioma.

The aim of this study was to investigate the hypothesis of an increased risk of pleural mesothelioma due to co-exposure to asbestos and refractory ceramic fibres (RCF) compared to asbestos exposure alone. Males were selected from a French case-control study conducted in 1987-1993 and from the French National Mesothelioma Surveillance Program in 1998-2006. Two population controls were frequency matched to each case by year of birth. Complete job histories were collected and occupational asbestos and RCF exposures were assessed using job exposure matrices. The dose-response relationships for asbestos exposure were estimated from an unconditional logistic regression model in subjects exposed to asbestos only (group 1) and subjects exposed to both asbestos and RCF (group 2). A total of 988 cases and 1125 controls ever-exposed to asbestos were included. A dose-response relationship was observed in both groups but it was stronger in group 2. In comparison with subjects exposed at the minimum value of the cumulative index of exposure, the odds ratio was 2.6 (95% CI 1.9-3.4) for subjects exposed to 75 fibres · mL(-1) · year(-1) in group 1 increasing to 12.4 (95% CI 4.6-33.7) in group 2. Our results suggest that the pleural carcinogenic effect of occupational asbestos exposure may be modified by additional exposure to RCF.

Pleural mesothelioma and occupational coexposure to asbestos, mineral wool, and silica.

RATIONALE: Occupational coexposure to asbestos and other fibers or particles could modify the carcinogenicity of asbestos with regard to pleural mesothelioma. OBJECTIVES: To estimate associations between pleural mesothelioma and occupational mineral wool and silica exposure and to study the impact of occupational coexposure on the risk of pleural mesothelioma. METHODS: A total of 1,199 male cases and 2,379 control subjects were included in a French pooled case-control study. Complete job histories were collected, and occupational exposure to asbestos, mineral wool (MW), and silica were assessed by three French job exposure matrices. Unconditional logistic regression models adjusted for age, birth date, and occupational asbestos exposure were used to estimate odds ratios (OR) and 95% confidence intervals (CIs). MEASUREMENTS AND MAIN RESULTS: A significant association between mesothelioma and MW exposure was observed after adjustment for occupational asbestos exposure. OR for subjects exposed to less than 0.01 fibers·ml(-1)·yr(-1) was 1.6 (95% CI, 1.2-2.1) and increased to 2.5 (95% CI, 1.8-3.4) for subjects exposed to more than 0.32 fibers·ml(-1)·yr(-1). All ORs for silica exposure were around the null. Coexposure to either asbestos and MW or asbestos and silica seemed to increase the risk of pleural mesothelioma. ORs were 17.6 (95% CI, 11.8-26.2) and 9.8 (95% CI, 4.2-23.2) for subjects exposed to both asbestos and MW and for subjects exposed to both asbestos and silica, respectively, compared with 4.3 (95% CI, 1.9-9.8) for occupational asbestos exposure alone. CONCLUSIONS: Our results are in favor of an increased risk of pleural mesothelioma for subjects exposed to both asbestos and MW or asbestos and silica.

Compensation of pleural mesothelioma in France: data from the French National Mesothelioma Surveillance Programme.

BACKGROUND: The aim of this study was to determine the rates of compensation awarded to patients presenting with pleural mesothelioma and factors linked to such compensation in France. METHODS: The study population consisted of 2,407 patients presenting with pleural mesothelioma, recorded by the National Mesothelioma Surveillance Programme between January 1, 1999 and December 31, 2009. Analysis of claims for recognition as "occupational disease" (OD) and claims for compensation by the Compensation Fund for Asbestos Victims (FIVA) were analyzed. RESULTS: Approximately 30% of subjects presenting with pleural mesothelioma, affiliated to the General National Health Insurance fund, neither sought recognition as an OD nor claimed for FIVA compensation. Gender, age at diagnosis, type of health insurance, and socio-professional category influence the likelihood of patients presenting with mesothelioma seeking compensation for this disease. CONCLUSIONS: Results show an under-compensation of pleural mesothelioma as OD and by the FIVA in France.

Wood dust in France. Trends in the population of exposed workers between 1982 and 2017 based on a job-exposure matrix assessment.

OBJECTIVE: Many occupations and industries use wood as a raw material and wood dust is a well-known carcinogen. This study presents trends in occupational exposure to wood dust for all workers (employees and self-employed workers) in France between 1982 and 2017 and focuses on the exposed workers in 2017. METHODS: Exposures to this carcinogen were assessed using the Matgéné job-exposure matrix. Trends in the prevalence and proportion of exposure over the study period were estimated by linking the matrix with population data from the 1982, 1990, 1999, 2007, and 2017 censuses and are described for selected industry groups. RESULTS: The number of exposed workers to wood dust has decreased significantly over the last 40 years, from 466,900 potentially exposed workers in 1982 to 305,000 workers in 2017. The proportion of exposed workers has also decreased over time, although not uniformly across industries. Increases in the proportion of exposed workers are observed in certain industries, such as "Sawmilling and logging" (from 61.2% to 73.6% over the period for men) and "Finishing of sale premises" (from 3.3% to 6.2% for women). CONCLUSION: This article is the first to describe occupational exposure to wood dust in France for all workers and to follow its evolution over the last 40 years. Occupations and industries still at risk in 2017 are also described with the aim of helping to improve prevention policies.

Temporal patterns of occupational asbestos exposure and risk of pleural mesothelioma.

Asbestos is the primary cause of pleural mesothelioma (PM). The objective of this study was to elucidate the importance of different temporal patterns of occupational asbestos exposure on the risk of PM using case-control data in male subjects. Cases were selected from a French case-control study conducted in 1987-1993 and the French National Mesothelioma Surveillance Program in 1998-2006. Population controls were frequency matched to cases by year of birth. Occupational asbestos exposure was evaluated with a job-exposure matrix. The dose-response relationships were estimated using restricted cubic spline functions in logistic regression models. A total of 2,466 ever-asbestos-exposed males (1,041 cases and 1,425 controls) were used. After adjustment for intensity and total duration of occupational asbestos exposure, the risk of PM was lower for subjects first exposed after the age of 20 yrs and continued to increase until 30 yrs after cessation of exposure. The effect of total duration of exposure decreased when age at first exposure and time since last exposure increased. These results, based on a large population-based case-control study, underline the need to take into account the temporal pattern of exposure on risk assessment.

Choice of rating method for assessing occupational asbestos exposure: study for compensation purposes in France.

BACKGROUND: In the course of setting up the National Mesothelioma Surveillance Program (PNSM), established in France in 1998, the question arose as to the most suitable method of assessing occupational exposure. The aim of this study was to define the most suitable rating method for assessing occupational asbestos exposure in order to assess medico-social care. METHOD: The study included 100 subjects-50 cases of mesothelioma and 50 controls-randomly selected and representing 457 jobs held. Job asbestos exposure was assessed by a six-expert panel using two methods: "by job" rating, where all the jobs in were assessed regardless of the subjects; and "by subject" rating, where all the jobs of a subject were assessed at the same time. Consensus was obtained and subjects' exposure was calculated for each rating. Then, two internal experts assessed job asbestos exposure with the "by subject" rating. Kappa coefficients were used to measure agreement between the ratings. RESULTS: Agreement between "by job" and "by subject" ratings was very good for subject probability of exposure (kappa = 0.84) and cumulative exposure index (kappa = 0.80). Agreement between the six-expert panel and the two internal experts was good for subject exposure (kappa for probability = 0.71; kappa for cumulative exposure index= 0.68). CONCLUSION: This study shows that the two rating systems have good or very good agreement. These results validate the routine use in the PNSM of the "by subject" rating, with the advantage of being convenient and quick to provide feedback on occupational asbestos exposure to mesothelioma cases for compensation.

Occupational and residential exposure to electromagnetic fields and risk of brain tumors in adults: a case-control study in Gironde, France.

The etiology of brain tumors remains largely unknown. Among potential risk factors, exposure to electromagnetic fields is suspected. We analyzed the relationship between residential and occupational exposure to electromagnetic field and brain tumors in adults. A case-control study was carried out in southwestern France between May 1999 and April 2001. A total of 221 central nervous system tumors (105 gliomas, 67 meningiomas, 33 neurinomas and 16 others) and 442 individually age- and sex-matched controls selected from general population were included. Electromagnetic field exposure [extremely low frequency (ELF) and radiofrequency separately was assessed in occupational settings through expert judgement based on complete job calendar, and at home by assessing the distance to power lines with the help of a geographical information system. Confounders such as education, use of home pesticide, residency in a rural area and occupational exposure to chemicals were taken into account. Separate analyses were performed for gliomas, meningiomas and acoustic neurinomas. A nonsignificant increase in risk was found for occupational exposure to electromagnetic fields  [odds ratio (OR = 1.52, 0.92-2.51)]. This increase became significant for meningiomas, especially when considering ELF separately [OR = 3.02; 95 percent confidence interval (95% CI) =1.10-8.25]. The risk of meningioma was also higher in subjects living in the vicinity of power lines (<100 m), even if not significant (OR = 2.99, 95% CI 0.86-10.40). These data suggest that occupational or residential exposure to ELF may play a role in the occurrence of meningioma.

Matgéné: a program to develop job-exposure matrices in the general population in France.

OBJECTIVES: Matgéné is a program to develop job-exposure matrices (JEMs) adapted to the general population in France for the period since 1950. The aim is to create retrospective exposure assessment tools for estimating the prevalence of occupational exposure to various agents that can then be correlated to health-related parameters. METHODS: JEMs were drawn up by a team of six industrial hygienists who based their assessments on available occupational measurement, economic and statistical data, and several thousand job descriptions from epidemiological studies performed in France since 1984. Each JEM is specific to one agent, assessing exposure for a set of homogeneous combinations (occupation × activity × period) according to two occupational classifications (ISCO 1968 and PCS 1994) and one economic activities classification (NAF 2000). The cells of the JEM carry an estimate of the probability and level of exposure. Level is estimated by the duration and intensity of exposure-linked tasks or by description of the tasks when exposure measurement data are lacking for the agent in question. The JEMs were applied to a representative sample of the French population in 2007, and prevalence for each exposure was estimated in various population groups. All documents and data are available on a dedicated website. RESULTS: By the end of 2010, 18 JEMs have been developed and eight are under development, concerning a variety of chemical agents: organic and mineral dust, mineral fibers, and solvents. By implementation in the French population, exposure prevalences were calculated at different dates and for complete careers, and attributable risk fractions were estimated for certain pathologies. Some of these results were validated by comparison with those of other programs. DISCUSSION: Initial Matgéné JEMs results are in agreement with the French and international literature, thus validating the methodology. Exposure estimates precision, however, vary between agents and according to the amount of exposure measurement data available. These JEMs are important epidemiological tools, and improving their quality will require investment in occupational health data harvesting, especially in the case of low-level exposures.

Development of a Job-Exposure Matrix for Ultrafine Particle Exposure: The MatPUF JEM.

OBJECTIVE: Ultrafine particles (UFPs) are generated from common work processes and have thus existed for a long time. Far more prevalent than engineered nanoparticles, they share common toxicological characteristics with them. However, there is no existing retrospective assessment tool specific to UFPs, for example, for epidemiological purposes. Thus, we aimed to develop a job-exposure matrix dedicated to UFPs. METHOD: Fifty-seven work processes were identified as well as the chemical composition of UFPs emitted, following a literature review and the input of an expert panel. These work processes were associated with occupational codes as defined by the ISCO 1968 classification. The probability and frequency of UFP exposure were assessed for each combination of occupational code and process. Summarized probabilities and frequencies were then calculated for all ISCO occupational codes associated with several processes. Variations in exposure over time or across industrial sectors were accounted for in the assessment of each occupational code. RESULTS: In the ISCO classification, 52.8% of the occupational codes (n = 835) assessed were associated with exposure to UFPs, consisting mainly of carbonaceous, metallic, and mineral families (39.5%, 22 and, 15.8%, respectively). Among them, 42.6% involved very probable exposure, and at a high frequency (regularly or continuously). CONCLUSION: These results suggest that occupational exposure to UFPs may be extensive at the workplace and could concern a wide variety of workers. Pending the integration of a third parameter assessing the intensity of UFP exposure, the MatPUF JEM already constitutes a promising and easy-to-use tool to study the possible adverse health effects of UFPs at work. It may also guide prevention policies in the occupational environments concerned, including those involving engineered nanoparticles.

Attributable risk in men in two French case-control studies on mesothelioma and asbestos.

Pleural mesothelioma is a primary tumor of the pleura that is mainly due to asbestos exposure. To study the relationship between mesothelioma and occupational asbestos exposure in France, two case-control studies (A and B) were conducted. A substantial difference in the attributable risk in the population (AR(p)) was observed among men: 44.5% (95% CI: [32.6-56.4]) in study A and 83.2% (95% CI: [76.8-89.6]) in study B. As different exposure assessment expert methods were used, the main objective of this work was to re-estimate the AR(p) men in two case-control studies according to a common standardized exposure assessment by using a Job Exposure Matrix (JEM) and to assess the role of subjects' selection. The initial observed AR(p) difference was maintained: 36.3% (95% CI: [24.3-50.3]) in study A and 69.7% (95% CI: [51.7-83.2]) in study B. Further investigations highlighted the potential selection bias introduced in both studies, especially among controls. The AR(p) could be underestimated in study A and overestimated in study B. After weighting subjects according to distribution of socio-economic status in the general population for controls and according to distribution of socio-economic status of cases registered by the French National Mesothelioma Surveillance Program, re-estimated AR(p) values were 52.4% in study A and 70.2% in study B. These results provide additional information to describe the relationship between pleural mesothelioma and occupational asbestos exposure, but also confirm the importance of subjects' recruitment in case control studies, particularly control selection.

Occupations and industries in France at high risk for pleural mesothelioma: A population-based case-control study (1998-2002).

BACKGROUND: Occupational exposure to asbestos, widely used in various industries for decades, is the most important risk factor for pleural mesothelioma. We report here the ranking of occupations and industries in France at high risk for this cancer among men and women. METHODS: A population-based case-control study, conducted from 1998 to 2002, included 462 cases (80.3% men) and 897 controls. Data were collected in face-to-face interviews with a standardized questionnaire. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated for each occupation and industry; subjects never employed in each category were the reference. RESULTS: For men, risks were high for several occupations and industries. Besides the expected high risks for non-metallic mineral product makers and manufacturing asbestos products, occupations such as plumbers (OR = 5.57, 95% CI: 2.90-10.69), sheet-metal workers, welders, metal molders, coremakers, and cabinetmakers were also at high risk. Elevated risks were found in the industries of shipbuilding (OR = 9.13, 95% CI: 5.20-16.06) and construction, but also in the manufacturing of metal products, chemicals, and railroad and aircraft equipment. The results for women showed increased but not significant risks in several occupational activities. CONCLUSIONS: This report provides new insight into the epidemiology of mesothelioma, confirming risks for occupational activities reported earlier and pointing out risks in activities never previously reported. It offers guidance to authorities for the compensation of asbestos victims and for prevention in at-risk activities still involving asbestos-containing products.

Qualitative and Semiquantitative Assessment of Exposure to Engineered Nanomaterials within the French EpiNano Program: Inter- and Intramethod Reliability Study.

The relatively recent development of industries working with nanomaterials has created challenges for exposure assessment. In this article, we propose a relatively simple approach to assessing nanomaterial exposures for the purposes of epidemiological studies of workers in these industries. This method consists of an onsite industrial hygiene visit of facilities carried out individually and a description of workstations where nano-objects and their agglomerates and aggregates (NOAA) are present using a standardized tool, the Onsite technical logbook. To assess its reliability, we implemented this approach for assessing exposure to NOAA in workplaces at seven workstations which synthesize and functionalize carbon nanotubes. The prediction of exposure to NOAA using this method exhibited substantial agreement with that of the reference method, the latter being based on an onsite group visit, an expert's report and exposure measurements (Cohen kappa = 0.70, sensitivity = 0.88, specificity = 0.92). Intramethod comparison of results for exposure prediction showed moderate agreement between the three evaluators (two program team evaluators and one external evaluator) (weighted Fleiss kappa = 0.60, P = 0.003). Interevaluator reliability of the semiquantitative exposure characterization results was excellent between the two evaluators from the program team (Spearman rho = 0.93, P = 0.03) and fair when these two evaluators' results were compared with the external evaluator's results. The project was undertaken within the framework of the French epidemiological surveillance program EpiNano. This study allowed a first reliability assessment of the EpiNano method. However, to further validate this method a comparison with robust quantitative exposure measurement data is necessary.

Risk of lung cancer associated with occupational exposure to mineral wools: updating knowledge from a french population-based case-control study, the ICARE study.

OBJECTIVES: To assess the risk of lung cancer associated with exposure to mineral wools (MWs), while taking into account smoking, asbestos, and crystalline silica exposures. METHODS: The analyses were restricted to men (1350 cases and 1912 controls). Lifelong occupational history was collected. MWs and asbestos exposures were assessed, using task-exposure matrices and silica exposure, a job-exposure matrix. RESULTS: We observed consistent not-significant increased risks of lung cancer of the same order of magnitude among workers exposed to high levels of MWs (odds ratio, 1.4; 95% confidence interval: 0.9 to 2.2; for highest quartile of the Cumulative Exposure Index). CONCLUSIONS: These results do not allow to draw firm conclusion about a carcinogenic effect of MWs on the lung, but they cannot exclude it. Given the high number of potentially exposed workers, it will be necessary to replicate them in a future further removed from the asbestos ban.