Biomedical subjects

Alain Bergeret

Publications and source records attributed to Alain Bergeret.

9 recordsLinked to original sources

PubMed2006

Case-control study on renal cell cancer and occupational exposure to trichloroethylene. Part II: Epidemiological aspects.

To test the effect of the exposure to trichloroethylene (TCE) on renal cell cancer (RCC) risk, a case-control study was performed in the Arve Valley (France), a geographic area with a high frequency and a high degree of such exposure. Cases and controls were selected from various sources: local general practitioners and urologists practicing in the area and physicians (urologists and oncologists) from other hospitals of the region who might treat patients from this area. Blinded telephone interviews with cases and controls were administered by a single trained interviewer using occupational and medical questionnaires. The analysis concerned 86 cases and 316 controls matched for age and gender. Three approaches were developed to assess the link between TCE exposure and RCC: exposure to TCE for at least one job period (minimum 1 year), cumulative dose (number of p.p.m. of TCE per job period multiplied by the number of years in the job period) and the effect of exposure to peaks. Multivariate analysis was performed taking into account potential confounding factors. Allowing for tobacco smoking and Body Mass Index, a significantly 2-fold increased risk was identified for high cumulative doses: odds ratio (OR)=2.16 (1.02-4.60). A dose-response relationship was identified, as was a peak effect; the adjusted OR for highest class of exposure-plus-peak being 2.73 (1.06-7.07). After adjusting for exposure to cutting fluids the ORs, although still high, were not significant because of lack of power. This study suggests an association between exposures to high levels of TCE and increased risk of RCC. Further epidemiological studies are necessary to analyze the effect of lower levels of exposure.

Aged↗

PubMed2006

Case-control study on renal cell cancer and occupational exposure to trichloroethylene. Part I: Exposure assessment.

A method for a semi-quantitative retrospective assessment of exposure to trichloroethylene (TCE) was implemented for a case-control study conducted in the Arve valley (France), an area with a widely developed screw-cutting industry, where teams of occupational physicians have collected a large quantity of well-documented measurements. A task-exposure matrix was developed to link the main working circumstances in a screw-cutting workshop to corresponding TCE-exposure levels: a 'basic level' was assigned to each task, standing for usual working procedures; exposure circumstances, such as duration or distance from the TCE source, were introduced as corrective factors. In parallel, a detailed occupational questionnaire was designed, setting subjects' descriptions of their successive jobs and working circumstances against levels assessed in the matrix. Possible exposure to TCE, plus some other occupational compounds (other solvents, oils, some metals, asbestos, welding fumes and ionizing radiations), were assessed for any job in all job histories. An average level of exposure to TCE, related to an 8 h usual working day, was attributed to each job period in turn, which was then categorized into six classes: 0; 1-35; 35-50; 50-75; 75-100; and >100 p.p.m. A total of 402 study subjects described their occupational life (average 3.7 jobs/subject, from 1924 to 2003). About 19% of the 1486 job periods described were assessed as being exposed to TCE; of these, 72.2% involved levels<35 p.p.m., 13.2% involved levels>50 p.p.m. and 5.4% above the French occupational exposure limit of 75 p.p.m. (TWA 8 h). A total of 41 job periods included exposure with peaks. Compared with levels encountered in other studies, the more severely exposed part of our study population seemed more exposed than most other populations previously studied, owing to vapor degreasing practices.

Carcinogens↗

PubMed2004

Respiratory function among waste incinerator workers.

INTRODUCTION: Whereas air pollutants have been measured in incinerator working areas, few studies have focused on the effects of these pollutants on the lung function of incinerator workers. In France, a study was performed among workers at two urban incinerators, aimed at identifying a link between exposure to different pollutants in incinerator plants and respiratory lung function impairments. METHODS: A follow-up of lung function was carried out on 83 incinerator workers from two incinerator plants, comparing them with a group of 76 non-exposed workers recruited by the same occupational physician. Workers' lung functions were measured during their yearly occupational medical examination, for 3 years. The American Thoracic Society quality criteria were used to control the quality of the flow-volume curves. RESULTS: Base-line lung functions were lower among incinerator workers than among non-exposed workers. The few significant differences were indicative of obstructive symptoms. During the first year the differences observed between the two groups were close to the significant threshold value of 5% for FEF(75)/ PV and FEF(25-75)/PV. During the third year significant differences covered three parameters: FEF(50)/PV, FEF(25-75)/PV and FEF(25-75)/FVC. After smoking habits (pack-years), medical history of allergy or lung diseases and the examination centres had been taken into account in a linear regression, the reduction of FEF(75)/PV in the first year and FEF(25-75)/FVC in the third year was linked to exposure in incinerator plants. There was no significant association between exposure and the differences observed in the FEF(25-75)/PV in the first year or in the FEF(50)/PV and the FEF(25-75)/PV in the third year. CONCLUSION: This analysis of incinerator workers' lung functions has identified some lung impairments among workers exposed to incinerator air pollutants compared to non-exposed workers, thus indicating possible obstructive disorders among incinerator workers. However, these impairments are moderate and in accordance with the low levels of airborne pollutants identified in a previous study.

Adult↗

PubMed2004

[Asbestos-related occupational cancers].

Due to its remarkable physical properties asbestos has been widely used in the industry. It is estimated that 25% of present French retired workers have been occupationally exposed to asbestos. A causal relationship between asbestos exposure and respiratory cancers is established since 1955 for lung cancer, and since 1960 for pleural mesothelioma. A causal relationship is also demonstrated for peritoneal and pericardic mesotheliomas, and strongly suspected for laryngeal cancers. It is estimated that occupational exposure to asbestos could be responsible for 5 to 20% of lung cancers and 80 to 90% of pleural mesothelioma, in men, in industrialized countries. The risk of cancer is positively correlated to cumulated exposure. No threshold has been demonstrated below which there is no increased risk of respiratory cancer.

Asbestos↗

PubMed2004

Systemic sclerosis and occupational risk factors: role of solvents and cleaning products.

OBJECTIVE: To analyze occupational and non-occupational exposure factors suspected of being associated with scleroderma (SSc), with a view to inculpating or excluding certain potentially toxic substances (e.g., solvents), thereby contributing to the recognition of such toxins in the field of occupational health. METHODS: The study comprised 10 men and 83 women diagnosed with SSc between 1995 and 1999 (American College of Rheumatology criteria) and early SSc, and 206 age and sex matched controls. The SSc registry is all-inclusive in the French administrative departments of Isere and Savoie so controls were randomly selected from the general population (using telephone directories) in these departments to ensure full representation. Exposure factors were analyzed for each subject by a personal questionnaire, and an individual evaluation was carried out by an industrial expert. Data were analyzed by conditional logistical regression adjusting for educational level. RESULTS: Construction workers were at significantly higher risk of contracting SSc; odds ratio (OR) = 4.01 (95% confidence interval 1.14-14.09). Analysis by industrial experts identified exposure to certain toxic substances regularly used by these same workers as risk factors for SSc: cleaning products: OR = 1.66 (0.90-3.08) (both sexes) and OR = 1.71 (0.92-3.20) (women only); solvents: OR = 3.23 (1.58-6.63) (both sexes) and OR = 2.80 (1.28-6.11) (women only); synthetic adhesives: OR 25.36 (1.36-472.28) (on 3 exposed cases). CONCLUSION: Exposure to either cleaning products or solvents emerged as a risk factor for SSc. Exposure factors should be characterized and results of all studies compared to implement appropriate preventive measures in relevant workplaces.

Adult↗

PubMed2003

Morbidity among municipal waste incinerator workers: a cross-sectional study.

OBJECTIVES: In order that the occupational exposures and health risks for municipal waste incinerator operators be better determined, a study was carried out in three centres. METHODS: A transversal study was carried out for 102 male incinerator workers matched for age with 94 male workers from other industrial activities. Three groups of exposed workers were considered (group 1: "crane operators" and "equipment operators"; group 2: "furnace " workers; group 3: "maintenance" and "effluent-treatment" workers). Data were collected through a questionnaire and medical examination. The respiratory function was explored and blood samples were taken for biological analysis. Statistical analysis using chi(2) or Student's test, and calculation of odds-ratio (OR) using logistic regression analysis were performed. RESULTS: There were no significant differences in general symptoms between the two groups. Skin symptoms (OR =4.85; 2.04-11.51 for the "maintenance and effluent" workers) were more often observed in the exposed group. An excess of respiratory problems was also encountered: daily coughing ["maintenance and effluent" groups (OR =2.55; 0.84-7.75); "furnace men" (OR =6.58; 2.18-19.85)]. A significant relationship between exposure and the decrease of several pulmonary parameters was observed. The liver and haematological tests were well within the normal range; nevertheless, a slight but significant increase in the white blood cells was observed in the exposed group. Higher blood lead levels were found for exposed workers. CONCLUSION: There were few adverse health effects in our morbidity study but skin irritation and cough were more frequent in the exposed workers. A slight decrease in pulmonary function was observed. These findings are in agreement with those of several other studies.

Accidents, Occupational↗

PubMed2003

Comparison of measurement strategies for prospective occupational epidemiology.

In the context of a prospective assessment of exposure for epidemiology, our objective is to obtain an optimal group-based design of allocation of a fixed total number of measurements. Such a design has been described by Ashford [Ashford JR. (1958) The design of a long-term sampling programme to measure the hazard associated with an industrial environment. J R Statist Soc A; 121: 331-47]. As this strategy is not operational, we developed three series of strategies: the first based on simplifications of Ashford's strategy; the second based on a pilot study; and the third on an iterative assessment of the group specific standard deviation of exposure. These strategies are compared by simulating a day-to-day individual exposure in several industrial sites and the resulting health effect. Our criteria for comparing strategies are the mean squared error of the estimated exposure in each group weighted by the number of subjects and the mean squared error of the estimated linear regression coefficient in the dose-response relationship. Strategies relying on an iterative approach have been found to perform best whatever the circumstances, nearly as well as Ashford's optimal strategy.

Humans↗

PubMed2002

Exposure to asbestos and lung and pleural cancer mortality among pulp and paper industry workers.

We studied the mortality from lung and pleural cancers in a cohort of 62,937 male workers employed for at least 1 year in the pulp and paper industry in 13 countries during 1945 to 1996. Mill departments were classified according to probability and level of exposure to asbestos on the basis of available dust measurements and mill-specific information on exposure circumstances. Thirty-six percent of workers were classified as ever exposed to asbestos. Standardized mortality ratios of lung cancer were 0.99 (95% confidence interval [CI], 0.90 to 1.08) among unexposed and 1.00 (95% CI, 0.90 to 1.11) among ever exposed workers. The number of pleural cancer deaths among unexposed workers was 10; that among exposed workers was 14, most of which occurred among maintenance workers. In internal analyses, a trend in mortality from either neoplasm was suggested for estimated cumulative exposure to asbestos, weighted for the individual probability of exposure within the department and for duration of exposure (relative risk for lung cancer for 0.78+ f/cc-years, as compared with < or = 0.01 f/cc-years: 1.44; 95% CI, 0.85 to 2.45; corresponding relative risk for pleural cancer: 2.43; 95% CI, 0.43 to 13.63). Despite a possible nondifferential misclassification of exposure and outcome, this study suggests that the carcinogenic effect of asbestos can be detected among workers employed in industries such as the pulp and paper industry, in which it is not considered to be a major hazard.

Air Pollutants, Occupational↗

PubMed2002

Mortality from lung cancer in workers exposed to sulfur dioxide in the pulp and paper industry.

Our objective in this study was to evaluate the mortality of workers exposed to sulfur dioxide in the pulp and paper industry. The cohort included 57,613 workers employed for at least 1 year in the pulp and paper industry in 12 countries. We assessed exposure to SO(2) at the level of mill and department, using industrial hygiene measurement data and information from company questionnaires; 40,704 workers were classified as exposed to SO(2). We conducted a standardized mortality ratio (SMR) analysis based on age-specific and calendar period-specific national mortality rates. We also conducted a Poisson regression analysis to determine the dose-response relations between SO(2) exposure and cancer mortality risks and to explore the effect of potential confounding factors. The SMR analysis showed a moderate deficit of all causes of death [SMR = 0.89; 95% confidence interval (CI), 0.87-0.96] among exposed workers. Lung cancer mortality was marginally increased among exposed workers (SMR = 1.08; 95% CI, 0.98-1.18). After adjustment for occupational coexposures, the lung cancer risk was increased compared with unexposed workers (rate ratio = 1.49; 95% CI, 1.14-1.96). There was a suggestion of a positive relationship between weighted cumulative SO(2) exposure and lung cancer mortality (p-value of test for linear trend = 0.009 among all exposed workers; p = 0.3 among workers with high exposure). Neither duration of exposure nor time since first exposure was associated with lung cancer mortality. Mortality from non-Hodgkin lymphoma and from leukemia was increased among workers with high SO(2) exposure; a dose-response relationship with cumulative SO(2) exposure was suggested for non-Hodgkin lymphoma. For the other causes of death, there was no evidence of increased mortality associated with exposure to SO(2). Although residual confounding may have occurred, our results suggest that occupational exposure to SO(2) in the pulp and paper industry may be associated with an increased risk of lung cancer.

Air Pollutants↗