Air Pollution Exposure and MS Relapse Risk in Humans

In a study of 1,152 patients with relapsing MS, increased weekly exposure to air pollutants (PM10, PM2.5, NO2) was linked to a higher risk of MS relapses within 2-12 week delays. Specifically, associations were observed for PM10 (IRR 1.28 at 2 weeks), PM2.5 (IRR 1.20 at 2 weeks), and NO2 (IRR 1.21 at 2 weeks, IRR 1.26 at 3 weeks, IRR 1.32 at 12 weeks).

Tags: #MSResearch
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Source: Read original source (PMID 42816171)

This plain-English summary was written by AI from a published abstract and may contain errors. It is not medical advice. Read the original study and talk to your MS team before making decisions about treatment.

Why it matters

These findings suggest that air pollution could contribute to MS relapse risk, highlighting an environmental factor in disease management.

What this does not prove

The study design has limitations, such as not fully isolating the effects of air pollution due to potential confounding variables and the exploratory nature of the temporal analysis.

Next milestone

No next milestone was established from the available source.

Study facts

Study design: Observational
Participants / samples: 1152 · basis not reported
Randomised: Not reported
Controlled: Not reported
Primary endpoint met: Yes
Relevant MS type: RRMS
Publication date: 2026-09-30
Evidence reviewed: Abstract only
Regulatory approval: Not reported
Research areas: Not classified

Original sources

Primary evidenceAir pollution and the risk of multiple sclerosis relapses in the Paris region, the CONFISEP study. ↗DOI: 10.1136/jnnp-2026-339534

Supporting passages (13)

study phaseTRIAL REGISTRATION NUMBER: NCT05033782.

study designWe conducted a bicentric retrospective cohort study in the Île-de-France region (2018-2021) including adults with relapsing MS from the Observatoire Français de la Sclérose en Plaques registry.

subjectsWe investigated whether weekly air pollution exposure was associated with delayed MS relapse risk up to 15 weeks.

sample sizeAmong 1152 patients (73.6% women; median age 37 years), 898 relapses occurred (0.20/patient-year).

peer reviewedJournal: Journal of neurology, neurosurgery, and psychiatry

primary endpoint metWeekly exposure to PM10, PM2.5 and NO2 was associated with increased MS relapse risk over delayed time windows ranging from 2- 3 weeks to 11-12 weeks.

relevant ms typesRESULTS: Among 1152 patients (73.6% women; median age 37 years), 898 relapses occurred (0.20/patient-year).

interventionWeekly exposure to particulate matter (PM)10, PM2.5, nitrogen dioxide (NO2) and ozone (O3) was estimated using Airparif street-level modelling data.

primary endpointWe investigated whether weekly air pollution exposure was associated with delayed MS relapse risk up to 15 weeks.

follow upup to 15 weeks.

findingsIn self-controlled analyses, PM10 exposure was associated with increased relapse risk at 2-week (incidence rate ratio (IRR) 1.28, 95% CI 1.05 to 1.57) and 11-week lags (IRR 1.26, 95% CI 1.02 to 1.54), PM2.5 exposure was associated with increased risk at 2-week (IRR 1.20, 95% CI 1.03 to 1.39), while NO2 exposure was associated with increased risk at 2-week (IRR 1.21, 95% CI 1.02 to 1.44), 3-week (IRR 1.26, 95% CI 1.04-1.52) and 12-week lags (IRR 1.32, 95% CI 1.12 to 1.56).

limitationsThese temporal windows should be considered exploratory given the multiple lag-specific analyses.

publication datePublication date: 2026-09-30

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