PM_2.5 exposure as a risk factor for multiple sclerosis. An ecological study with a Bayesian mapping approach.

Area of Science:

• Environmental epidemiology
• Neurology
• Public health

Background:

• Environmental factors are implicated in multiple sclerosis (MS) etiology.
• Air pollution, specifically particulate matter 2.5 (PM2.5), is a potential environmental risk factor.

Purpose of the Study:

• To investigate the association between PM2.5 concentrations and MS prevalence in Pavia, Italy.
• To identify geographical areas with elevated MS risk related to air pollution levels.

Main Methods:

• Analysis of spatial ground-level PM2.5 data (2010-2016) by municipality.
• Application of ecological regression and Bayesian statistics to assess PM2.5, urbanization, and deprivation index in relation to MS risk.
• Grouping municipalities into tertiles based on PM2.5 concentration.

Main Results:

• MS prevalence in Pavia was 169.4 per 100,000 inhabitants.
• Higher MS risk was observed in areas exceeding the European annual PM2.5 limit value (25 μg/m³).
• Bayesian mapping identified significant clusters of high MS risk.

Conclusions:

• A positive association exists between higher PM2.5 levels and increased MS risk.
• Lower PM2.5 concentrations were linked to lower MS risk.
• These findings support the hypothesis that air pollution is an environmental risk factor for multiple sclerosis.