RESUMEN
OBJECTIVE: To describe the proportions of subjects exposed to crystalline silica and the sectors of activity concerned between 1965 and 2010 in a sample of the general French population. METHODS: We included 2942 participants aged 40 to 65 years, recruited at random from electoral rolls, from the French general population in the cross-sectional ELISABET study between 2011 and 2013. The proportions of subjects exposed to crystalline silica and their sectors of activity were determined on the basis of their career history and the use of the Matgéné job-exposure matrix. RESULTS: In the total sample, occupational exposure to crystalline silica was found for 291 subjects (9.9%) between 1965 and 2010, with a predominance of men (20.2% of exposed subjects among men (282 out of 1394) versus 0.6% among women (9 out of 1548)). The highest proportion of participants exposed to crystalline silica was reached in 1980 with 6.1% and then decreases to 4.4% in 2010. Among men, the most frequently exposed sectors of activity were manufacture of basic metals (41.5% of exposed men (117 out of 282)), specialised construction activities (23.1% of exposed men (65 out of 282)) and construction of buildings (14.2% of exposed men (40 out of 282)). CONCLUSIONS: Although the proportion of workers exposed to crystalline silica has been decreasing since the 1980s, it is still significant at least until 2010, particularly in the construction sector, and further research is needed to improve the monitoring of workers who are or have been exposed to crystalline silica.
RESUMEN
INTRODUCTION: Although several studies have studied the relationship between occupational exposure to crystalline silica dust and respiratory mortality, few have examined the relationship with impairments in respiratory function and the exposure threshold triggering spirometric monitoring in exposed workers. The objective of the present study was to evaluate the impact of exposure to crystalline silica dust on respiratory function. METHODS: We included 1428 male participants (aged 40 to 65) recruited from the French general population, at random from electoral rolls, in the cross-sectional ELISABET study and for whom data on forced expiratory flow-volume curve indices z-scores (calculated using the Global Lung Function Initiative 2012 equations) and exposure (via a questionnaire) were available. A cumulative exposure index (CEI) for crystalline silica dust (CEIsilica, expressed in mg.m-3.year) was calculated using the Matgéné occupational exposure matrix. RESULTS: 293 of the 1428 participants (20.52%) reported exposure to silica dust. We found that the adjusted z-scores for the forced expiratory volume in the first second/forced vital capacity (FEV1/FVC) ratio decreased significantly as CEIsilica increased. After adjustment, the adjusted z-scores for FEV1/FVC (ß: -0.426 (95% confidence interval (CI): -0.792, -0.060) per 1 mg m-3.year increment) and the mean forced expiratory flow between 25 and 75% of the forced vital capacity (FEF25-75) (ß: -0.552 (95% CI: -0.947, -0.157)) were significantly lower in the participants with CEIsilica ≥1 mg m-3.year than in non-exposed participants. The likelihoods of having airway obstruction (odds ratio (OR): 3.056 (95% CI: 1.107, 7.626)) or having an impaired FEF25-75 (OR: 4.305 (95% CI: 1.393, 11.79)) were also significantly higher in participants with CEIsilica ≥1 mg m-3.year. CONCLUSION: Our results emphasize the importance of spirometry-based monitoring in workers exposed to more than 1 mg m-3.year of crystalline silica dust, in order to identify small airway obstruction or airway obstruction as early as possible.
