L. Garras

Matgene: 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.

Surveillance Programme of Work-related Diseases (WRD) in France

The surveillance programme of work-related diseases (WRD) is based on a network of occupational physicians who notify all WRD diagnosed during a two-week observation period. The aims are mainly to estimate the prevalence of non-compensated WRD in the working population according to socio economic factors; to determine new indicators of occupational health; to update the lists of compensable occupational diseases; to understand and assess under-compensation and under-notification. The participation rate for occupational physicians is around 33% in 2008. The main WRD are the musculoskeletal disorders, followed by the mental disorders. This 2-week protocol, repeated regularly, provides useful data on frequency of pathologies linked to employment as well as an estimate of unreported WRD subject to compensation or non-compensated WRDs, and the trends of WRDs over the time.

Évaluation quantitative du risque de cancer du poumon et de mésothéliome pleural chez les mécaniciens de véhicules automobiles

Position du probleme Une evaluation quantitative du risque de cancer (poumon et mesotheliome pleural) du a l’exposition a l’amiante dans la population des mecaniciens automobiles a ete effectuee. Methodes La population a ete selectionnee a partir des donnees du recensement de 1999 (INSEE), par classe d’âge de 5 ans, selon les secteurs d’activite et les professions et categories sociales dans la population active. Les calculs de risque ont ete effectues chez 242 360 hommes âges de 16 a 60 ans. L’exposition a l’amiante des mecaniciens est essentiellement associee au travail sur les organes friables des vehicules anterieurs a 1997. Les mesures d’empoussierement disponibles etaient d’une tres grande variabilite. Aucune donnee caracterisant le temps consacre a ces interventions au cours d’une semaine de travail n’existant, des profils hebdomadaires d’exposition ont ete simules a partir de differents niveaux associes aux tâches et de donnees issues de l’enquete SUMER 1994. Les modeles appliques sont ceux habituellement utilises par les autorites sanitaires internationales pour evaluer les effets cancerogenes du chrysotile. Les scenarios d’exposition introduits dans les calculs combinent differents niveaux attaches aux tâches effectuees avec deux periodes, differentes repartitions des proportions de mecaniciens exposes et deux dates d’extinction du parc automobile. Le scenario le plus realiste suppose que tous les mecaniciens ont ete exposes a l’amiante a un niveau se situant entre 0,06 et 0,25 fibres/ml hebdomadaires en moyenne pendant la periode anterieure a 1997, et entre 0,01 et 0,06 pendant la periode allant de 1998 a 2010. Resultats Selon ce scenario, le nombre de deces par cancer du poumon et par mesotheliome du a l’exposition a l’amiante (vie entiere) dans cette population de mecaniciens serait de 602 deces d’ores et deja « fixes » par l’exposition subie anterieurement a 2003 et donc inevitables, et 43 deces supplementaires si aucune mesure ne venait modifier l’etat du parc automobile.

0135 Prevalence of exposure to some occupational carcinogens in France: evolution between 1999 and 2007

Objectives To use job-exposure matrices (JEM), as a tool to describe trends of occupational exposure to carcinogenic chemicals present in the French workplace. Method MATGÉNÉ JEMs assess for each job and a given period in France, several exposure indices such as probability, intensity and frequency of exposure. Linking these matrices with job information data coming from French population allow to estimate the prevalence of workers exposed to several chemicals for a given year. To study the evolution of exposure to carcinogens, prevalence of exposure in France for the years 1999 and 2007 were estimated from the population census of 1999 and from a representative sample of the population in 2007. Results French available JEMs assess the exposure of workers since the 1950s for various occupational carcinogens: crystalline silica, benzene, trichlorethylene, perchlorethylene, leather dust, asbestos and refractory ceramic fibres (RCF). A significant decrease in the prevalence of exposure between 1999 and 2007 was observed among men for silica with 7.4% and 5.6% respectively, asbestos with 6.3% and 1.1% and RCF with 0.5% and 0.3%. For women, a significant decrease was also noticed for exposure to asbestos and leather dust. For solvents, the prevalence of exposure remained stable in both men and women. Conclusions The proportion of workers exposed to carcinogens, particularly to asbestos, has decreased in France since 1999. However a substantial number of workers are still exposed. As complete occupational histories are available in the 2007 population sample, the JEMs will also be used to estimate lifetime exposure prevalence and the associated disease burden.

An extensive epidemiological investigation of a kidney cancer cluster in a chemical plant: what have we learned?

Objectives In 2003, a cluster of renal cell carcinoma (RCC) cases was reported among men working at a French chemical plant using a proprietary process to produce vitamin A. The 10 index cases yielded a standardised incidence ratio of 13.1 for 1994–2002. Nine of these 10 cases were diagnosed by a plant-specific abdominal ultrasonography screening programme that targeted exposure to an intermediate chemical, 4-chloro-1,1-dimethoxy-3-methyl-2-butene, commonly named ‘chloracetal C5’, suspected as the cause by some experts. Epidemiological investigations sought to examine the relations between occupational exposures and RCC. Methods A retrospective cohort mortality study and a nested case–control study were conducted. The cohort study included all workers who had been employed at the plant for at least 6 months between 1960 and 2003. The case–control study included an extensive search within the region for other kidney cancer cases among the cohort members. Industrial hygienists assessed occupational exposure. Results From 1968 to 2006, no significant excess mortality was observed for all causes of death or for all cancers. We found excess mortality for kidney cancer only among women. The nested case–control study showed a dose–response relation for cumulative exposure to chloracetal C5: the OR rose from 2.5 in the low-exposure category to 10.5 in the high-exposure group. Adjustment for screening attenuated this relation. Conclusions The results of the case–control study were consistent with the positive results of in vivo genotoxic tests and suggest that chloracetal C5 can have a causal role in RCC.