Occupational quantitative exposure to crystalline silica, solvents, pesticides, and risk of clinical forms of systemic sclerosis

Objectives: To estimate the association between SSc clinical phenotypes and quantitative occupational exposure to crystalline silica, chlorinated solvents, trichloroethylene, and pesticides using job-exposure matrices.

Methods: In the VISS-EXPOSITION transversal study, data on declarative occupational exposure to crystalline silica, solvents, and pesticides were retrieved. In parallel, the Lifetime Occupational History was evaluated using a questionnaire and cursus laboris for SSc patients followed at Bordeaux University Hospital (France). Using job-exposure matrices, we assessed patients' occupational exposure in relation to relevant clinical phenotypic forms of the disease.

Results: Toxic exposure to crystalline silica and pesticides is underestimated by patients. Non-biased job-exposure matrices retrieved more exposed patients than the declarative assessment (10.1% of patients by job-exposure matrices versus 6.3% by declaration for crystalline silica and 25.9% versus 12.2% for pesticides). Patients overestimate their solvent exposure (7.9% for chlorinated solvents and 4.8% for trichlorethylene assessed by job-exposure matrices and 24.4% declarative exposure to solvents at large). Clinical form evaluation revealed a nonsignificant trend toward an increased risk of crystalline silica occupational exposure in the pulmonary fibrotic group of SSc patients (OR 3.12 CI 95% [0.80-12.15]). We also observed a nonsignificant trend toward elevated OR (OR 2.89 CI 95% [0.93-8.95]) for chlorinated solvent occupational exposure and the vascular phenotype of SSc. Of note, pesticide occupational exposure evaluation represents one of the largest to date in SSc patients.

Conclusion: This study emphasizes that many exposed SSc patients are unaware of their occupational exposure. Job-exposure matrices allow better exposure screening for SSc secondary prevention and occupational exposure compensation.

Clinical trial registration: clinicaltrials.gov, https://www.clinicaltrials.gov, NCT03543956.