A NEW study has provided strong genetic evidence linking air pollution to the development of several autoimmune diseases, highlighting the role of environmental factors in immune system dysfunction. The research used a two-sample Mendelian randomisation approach to examine the causal relationships between common air pollutants and autoimmune diseases (ADs), revealing significant associations with conditions such as rheumatoid arthritis (RA), Sjögren’s syndrome (SS), systemic lupus erythematosus (SLE), ulcerative colitis, and psoriasis.
Researchers analysed genetic data from genome-wide association studies (GWAS) and used single nucleotide polymorphisms (SNPs) related to five common air pollutants as instrumental variables. The findings showed that exposure to nitrogen oxides significantly increased the risk of RA (47% higher), SS (129% higher), and SLE (626% higher). Additionally, fine particulate matter (PM2.5) was identified as a risk factor for ulcerative colitis, while PM10 was associated with an increased risk of psoriasis. Interestingly, a negative association was observed between certain coarse particulate matter (PM2.5–10) and SS, suggesting that not all pollutants have the same effect.
Further analysis explored how lifestyle-related risk factors, such as smoking and body mass index (BMI), mediate the impact of air pollution on autoimmune diseases. The results indicated that smoking accounted for 9% of the effect of nitrogen oxides on RA, while BMI contributed to 6% of the effect. This suggests that reducing exposure to air pollution, along with managing lifestyle risk factors, could play a critical role in preventing autoimmune diseases.
These findings provide compelling evidence that air pollution is not just an environmental concern but a significant contributor to autoimmune disease risk. Given the rising prevalence of ADs globally, the study underscores the urgent need for stricter air quality regulations and public health initiatives to mitigate the impact of air pollution on immune health.
Aleksandra Zurowska, EMJ
Reference
Zhang M et al. Causal relationships between air pollution and common autoimmune diseases: a two-sample Mendelian randomization study. Sci Rep. 2025;DOI: 10.1038/s41598-024-83880-9.
