Objectives: The aim of the study is to explore possible relationships between occupational exposures and Multiple Sclerosis (MS), whose etiology is not well defined yet. To date, only few literature data are available on this subject.
Methods: We carried out a case-control study, where cases were MS patients included in the MS Register of the Province of Pavia, Northern Italy, and controls, 1:4 matched by sex and age (5 years classes), were randomly selected from the National Health Service population files. The occupational histories were obtained from Italian Institute for Social Security (INPS) archives by automatic linkage using Italian Occupational Cancer Monitoring (OCCAM) method that estimates the risk of specific occupational cancers, by geographic area and industrial sector. OR adjusted for sex and age and corresponding 90% confidence intervals were used to estimate the association between exposure and disease.
Results: We included in the study 227 MS patients (130 (57.3%) female, 97 (42.7%) male) and 907 controls (514 (56.7%) female, 393 (43.3%) male). Our results suggest an increased risk for men in mechanical manufacturing industry (OR 1.71, 90% CI 1.03-2.85) and agriculture (OR 2.47, 90% CI 1.03-5.91). Women show an increased risk in mechanical manufacturing industry (OR 2.05, 90% CI 1.22-3.45), agriculture (OR 2.57, 90% CI 1.09-6.09) and leather/shoe industry (OR 2.34, 90% CI 1.06-5.20).
Conclusions: Our preliminary findings indicate that solvent exposures could be related to the risk of MS, as both shoe/leather workers and mechanical manufacturing industry workers are exposed to organic solvents. Interestingly, a major risk of MS was also found among workers engaged in agriculture, suggesting a role of pesticides, whose neurotoxic effect is well known.