Ozone pollution as a possible trigger for multiple sclerosis in young people: the PEDIGREE study

Background: Air pollution is linked to an increased risk of multiple sclerosis (MS) in adults. Objective: To investigate the link between air pollutant exposure and pediatric MS (pedMS) in an Italian cohort. Methods: PEDIGREE (Pediatric Italian Genetic and Environment Exposure) is a multicenter case–control study investigating genetic and environmental factors in MS before the age of 18. Information on environmental and perinatal exposures was collected through the PEQ-IT questionnaire. Air pollution data during the first, second, and third years prior to MS onset (PM2.5, PM10, O3, NO2, SO2, and CO levels) were obtained from the European Monitoring and Evaluation Program database. Results: Data were available for 113 pedMS cases and 117 controls. We found statistically significant associations between pedMS and higher exposure to ozone (O3) in the first (OR = 1.11; 95% CI 1.03–1.19; p = 0.007), second (OR = 1.10; 95% CI 1.02–1.18; p = 0.012), and third (OR = 1.09; 95% CI 1.01–1.17; p = 0.025) year before MS onset, even after adjusting for gender, age at onset, sun exposure, parental smoking habit, and socioeconomic background. A one-unit increase in O3 exposure was associated with a roughly 10% increase in pedMS risk. Discussion: O3 may play a significant role in the development of MS by promoting inflammation and oxidative stress.