NEW research suggests that exposure to PFAS, particularly when combined with related pollutants, is associated with higher odds of multiple sclerosis, with genetic factors further shaping individual vulnerability.
Environmental Exposure and PFAS in Neurological Disease
PFAS are persistent environmental chemicals widely used in industrial applications and consumer products, leading to long term human exposure. These substances often co-occur with other persistent organic pollutants, including hydroxylated PCBs, creating complex exposure mixtures. While PFAS have previously been linked to immune and metabolic effects, their role in neurological disease has remained unclear.
PFAS Mixtures, Genetics and Multiple Sclerosis Risk
The study analysed data from the Swedish population based Epidemiological Investigation of Multiple Sclerosis cohort, including 907 MS cases and 907 matched controls. Researchers measured serum concentrations of 14 PFAS and three hydroxylated PCBs, applying logistic regression and quantile g computation to capture both individual and combined effects. Several compounds showed nonlinear associations with MS odds, including PFOS, perfluorononanoic acid, 4-OH-CB187, and 3-OH-CB153. Mixture modelling demonstrated that combined exposure to PFAS and OH-PCBs significantly increased MS odds, even when individual associations were modest. A key gene environment interaction emerged for PFOS. Among carriers of the HLA-B*44:02 allele, increasing PFOS exposure was associated with more than a fourfold higher odds of MS. In contrast, non-carriers showed only a ∼ 60 % increase in MS odds at the highest exposure quartile compared with the lowest. These associations remained after adjustment for lifestyle factors and other MS related HLA variants, highlighting the independent contribution of PFAS mixtures.
Clinical And Public Health Implications of PFAS Findings
Although observational, these findings have important implications for clinical awareness and environmental health policy. Clinicians managing patients at risk of multiple sclerosis may need to consider environmental exposures alongside genetic background. The results also strengthen arguments for assessing chemical mixtures rather than single substances in risk evaluation. Future research should explore biological mechanisms linking PFAS to immune dysregulation and neuroinflammation, while public health strategies aimed at reducing PFAS exposure could form part of broader MS prevention efforts.
Reference
Vaivade A et al. Co-exposure to PFAS and hydroxylated PCBs is associated with increased odds of multiple sclerosis. Environment International. 2025:109993.
