Effects of talc dust on respiratory health: results of a longitudinal survey of 378 French and Austrian talc workers.

OBJECTIVES: The aim of this longitudinal study was to investigate the effects on respiratory health of talc dust, free of asbestiform fibres, at or below airborne concentrations of 2 mg/m(3). METHODS: The respiratory health and dust exposure of all workers with at least 5 years of employment at two talc producing facilities in France and Austria were surveyed between 1988 and 2003. Standard forced expiratory volumes and standard chest x rays were obtained on repeated occasions and recorded using strict quality control procedures. Of a target population of 430 subjects, 378 (88%) were examined at least twice. A quantitative exposure matrix was set up based on 4602 personal exposure measurements of respirable dust and qualitative descriptions of the industrial processes and individual protection devices. RESULTS: The mean duration of follow-up was 14.5 years with a mean estimated talc dust concentration during follow-up of 1.46 mg/m(3). The prevalence of small radiological opacities and lung function parameters were significantly related to cumulative exposure at inclusion but not to exposure during the study period. Overall, the forced expiratory volume in 1 s decreased by 66 ml per 100 years.mg/m(3), which is less than that reported for other types of mineral dusts. CONCLUSIONS: Although early exposure levels to talc as assessed at inclusion were associated with decreased lung function and an increased prevalence of small radiological opacities, there was no evidence of detrimental effects of talc exposure, as assessed within the study period, on lung function and small radiological opacities.

Relationship between UVA protection and skin response to UV light: proposal for labelling UVA protection.

Definition and validation of a most relevant method to assess ultravoilet A (UVA) protection is a major concern for industry, authorities and consumers. However, due to the lack of knowledge about all the biological phenomena involved, the level of UVA protection needed, the ways to assess and label it, remain controversial. In order to overcome this situation, the paper deals with the outcomes of a mathematical model to calculate the distribution between ultravoilet B (UVB) and UVA components of skin responses to UV light. Mathematical calculations of UVB and UVA erythemal components of skin response to sunlight are developed from the well-known determination procedure to calculate the sunburn protection factor (SPF) of sunscreens. The model establishes the relationship between the UVA component of skin erythemal response to overall UV radiation received from sunlight and the ratio SPF/PFAe (erythemal protection factor) where SPF is the product and PFAe is related to the UVA part of the sunlight. Depending on the efficacy profile of sunscreens, the skin erythemal response may be mainly promoted by UVB rays as it normally occurs in unprotected skin or on contrary by UVA rays. Therefore, the efficacy profile of sunscreens defines the deepness where biological events induced by sunlight take place. This new relationship pinpoints the tremendous importance of the protection afforded by sunscreen products in the UVA range when erythema is taken as biological response. By extrapolation of the model to any other biological skin response it becomes possible to predict how to improve the efficiency of sunscreen products in the future. UVA protection afforded by sunscreens should be improved until reaching the same level as the SPF protection factor so that all UV-induced biological responses could be prevented or lowered at the same extend. To enforce this improvement, a proposal to classify sunscreen products in relation with their UVA protection is made.

A cohort mortality and nested case-control study of French and Austrian talc workers.

OBJECTIVES: To study whether the mortality from non-malignant and malignant respiratory diseases of workers employed in French and Austrian talc mines and mills is related to their long term occupational exposure. METHODS: Two historical cohorts were set up comprising all male subjects who had been working continuously for at least 1 year in a series of talc producing companies in France and Austria. The French cohort consisted of those employed at a site in the French Pyrenees and working between 1 January 1945 and 31 December 1994. The Austrian cohort consisted of the workers employed between 1 January 1972 and 31 December 1995 in one of four industrial sites in the Austrian Alps. The mortality within the cohorts was compared with local death rates. Two nested case-control studies focusing on non-malignant and malignant respiratory diseases were set up to estimate possible dose-response relations with cumulative exposure to talc dust based on an industry specific job exposure matrix. RESULTS: Mortality from lung cancer was in small excess in both cohorts (France, standardised mortality ratio (SMR) 1.23, 21 cases observed, 95% confidence interval (95% CI) 0.76 to 1.89; Austria, SMR 1.06, seven observed, 95% CI 0.43 to 2.19). A non-significant excess mortality was found for all non-malignant respiratory diseases in the French cohort due to a significant excess for pneumoconiosis (SMR 5.56, three observed, 95% CI 1.12 to 16.2). The case-control study of non-malignant respiratory disease showed an increased mortality in the highest exposure groups (odds ratio (OR) 2.5 for a cumulative exposure > or = 800 y.mg/m(3)) with a significant trend (OR/100 y.mg/m(3) 1.08) with cumulative exposure to talc. On the contrary, no increasing trend could be found in the case-control study of lung cancer. This result must be interpreted considering the small cohort size. Adjustment on smoking and exposure to quartz did not influence these results to any extent. CONCLUSIONS: The mortality from non-malignant respiratory disease was found to be related to high cumulative exposure to talc dust. The small excess in lung cancer does not seem to be attributable to talc.

Survey of the respiratory health of the workers of a talc producing factory.

OBJECTIVES: To assess the effect of an occupational exposure to talc dust on respiratory health. METHODS: 166 talc millers from a French factory underwent spirometry and filled in a standardised respiratory questionnaire during their annual medical visit in 1989. A full sized chest radiograph taken in 1987 for the subjects hired before 1982 was also available, for the others a radiograph taken when hired was used. Radiography was repeated in 1992 for all subjects still active at this date (n = 139). The occupational exposure to talc dust was characterised for each workplace with 1440 personal samples collected since 1986 and by semiquantitative estimates of the historical exposure. RESULTS: The geometric mean (range) of estimated exposure was 1.87 (0.5 to 50) mg/m3 and the estimated cumulative exposure at the date of spirometry was > 150 y mg/m3 for 41 subjects. After adjustment for smoking in a linear model the standardised residual values of both forced vital capacity and forced expiratory volume in one second decreased significantly with increasing exposure. The prevalence of dyspnoea also increased after adjustment for smoking categories and age in a logistic regression. The prevalence of small radiological opacities was significantly related to age and to the exposure after adjustment for age and smoking categories. The incidence of new opacities between the two radiographs (11 new opacities with a profusion higher than 0/1) was significantly related to smoking (10 out of 11 are smokers) but not to the exposure. CONCLUSION: This study shows an effect of high levels of talc dust both on functional variables and on the prevalence of small radiological images, but provides no clear evidence about the possible effect of present levels of exposure.

[Industrial factors in the etiology of obstructive respiratory diseases. Implications for prevention]. / Facteurs industriels dans l'étiologie des maladies respiratoires obstructives. Conséquences pour la prévention.

The statistics of occupational diseases in industrial medicine, as well as the markedly elevated incidence of chronic bronchitis amongst workers, show that there is an additional respiratory risk linked to industrial environment and the conditions of work. Epidemiological studies in industry and in particular certain occupations, such as mining and the construction industry have led to a better understanding of this industrial risk as a generator of the additional obstructive respiratory disease occurring in exposed workers. Among the unrecognised risks is the prolonged exposure to the oxides of nitrogen which are capable of affecting gas exchange, as has been shown in one of our investigations in the production of nitrogenous fertilizers, which explains the mechanism. In industrial medicine, a preventative strategy should be planned, on the one hand considering individual risks and taking account of personal and genetic factors, on the other hand monitoring of respiratory risks by the identification of new irritants and finally the organisation of respiratory function screening for the early detection of lung dysfunction, by more sensitive tests than the FEV1 (VEMS), whose validity should be studied. The priority is primary prevention by the suppression of toxic irritants and by the improvement of working conditions.

[Medico-social consequences of asthma in adults (author's transl)]. / Conséquences médico-sociales de la maladie asthmatique chez l'adulte.

The evaluation of the medico-social consequences of asthma in adults encounters difficulties that are inherent to a chronic disease with varying clinical pictures. Overall statistical analyses, particularly concerning mortality, provide little information in a socio-economical perspective, especially in France. However, based on the results of fragmentary but varied analyses, the study of this disease in relation to the working careers of asthmatic subjects underlines the importance of the repercussions at the very start of professional life (choice of profession, recruitement in a company). The study of absenteeism and inaptitude reveals to what degree these consequences are related to the seriousness of the disease and to the asthmatic person's social sphere. The same is true for family and social life which is more difficult to evaluate. Systematic analyses alone will be useful in determining whether asthma is considered a "social disease" with its eventual implications on a public health program.