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Air Pollution and Systemic Lupus

Written by Nicole Eike, Edited by Caitlin Monica Subijanto

Introduction

Autoimmune diseases occur when one’s immune system attacks the body’s own tissues. There are over 100 autoimmune diseases, which impact about 8% of Americans1, and cases have been rising globally. Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by an impaired inflammatory response where the immune system mistakenly attacks healthy cells and tissue.2 It is associated with various clinical manifestations, including life-threatening organ damage. Although the exact cause of SLE remains unknown, factors including genetics, environmental triggers, hormonal balances, and certain medication are believed to contribute to its onset and progression. While genetic predisposition is widely recognized as a key determinant of autoimmune disease risk, there is a growing body of research linking the development and severity of autoimmune diseases to environmental factors. This paper explores how exposure to air pollution can influence the risk and development of SLE.


Air Pollution

Air pollution is the release of harmful particles and gases into the atmosphere. Common pollutants of concern include particulate matter (PM2.5, PM10), nitrogen oxides (NOx), sulfur dioxide (SO₂), ground-level ozone (O₃), volatile organic compounds (VOCs), and heavy metals, such as mercury, lead, and cadmium. These contaminants arise from both outdoor sources, such as vehicle emissions, power plants, and industrial facilities, as well as indoor sources, such as secondhand smoke, cooking stoves, and cleaning products. PM2.5 is especially dangerous because it can penetrate deep into the lungs and enter the bloodstream.


Link Between Air Pollution and SLE

A growing body of research suggests an association between exposure to air pollution and the risk of SLE. A review of six studies found a statistically significant association between SLE risk and short-term exposure to PM2.5.3 A plausible mechanism underlying this association is that air pollution increases the release of inflammatory mediators in response to inflammation or injury. For people with SLE, this heightened immune system activity exacerbates tissue damage. Although these studies cannot establish causality, the consistency of the associations across various pollutants and populations strengthens the case that air quality contributes to increased SLE risk.


Despite the evidence, establishing a direct causal relationship remains challenging. Autoimmune diseases have complex origins, and genetic predisposition can interact with exogenous triggers. Pollution exposures also vary widely between individuals, and the relation between SLE risk and indoor air pollution has been studied far less than outdoor air pollution. Consequently, additional long-term and mechanistic studies are needed to clarify which pollutants, exposure windows, and biological pathways strongly contribute to SLE risk and development.


Social and Environmental Justice Dimensions

Air quality is unevenly distributed. Minority and low-income communities are disproportionately living near major sources of air pollution. Populations in lower- to middle-income regions experienced the highest levels of PM2.5 exposure, while high-income regions experienced the lowest levels of exposure.4 These disparities in air quality stem from the historical redlining of neighborhoods that concentrated communities of low socioeconomic status in more polluted areas. These communities are more likely to be closer in proximity to highways, industrial zones, and other sources of pollution. As a result, these populations face a disproportionately higher burden of adverse health outcomes, including an increased risk to autoimmune diseases such as SLE.


Conclusion

A growing body of evidence links exposure to air pollution, especially PM2.5, to increased risk and severity of SLE and other autoimmune diseases, including rheumatoid arthritis and type 1 diabetes. These conditions already account for significant healthcare expenses, and pollution-related drivers would increase this burden. Policy measures to mitigate the impact of PM2.5 exposure include strengthening air-quality standards, reducing fossil-fuel emissions, and improving environmental monitoring in high-risk areas, especially marginalized communities that bear the greatest burden of air pollution exposure. Continued research is needed to clarify a causal relationship between pollutant exposure and SLE risk, and stronger regulatory action is needed to reduce the health and social inequities linked to air pollution.

References


  1. Autoimmune Diseases | NIH: National Institute of Allergy and Infectious Diseases.; 2022. https://www.niaid.nih.gov/diseases-conditions/autoimmune-diseaseshttps://www.niaid.nih.gov/diseases-conditions/autoimmune-diseases

  2. Kiriakidou M, Ching CL. Systemic Lupus Erythematosus. Ann Intern Med. 2020;172(11):ITC81-ITC96. doi:10.7326/AITC202006020

  3. Rezayat AA, Niloufar Jafari, Mir Nourbakhsh SH, et al. The effect of air pollution on systemic lupus erythematosus: A systematic review and meta-analysis. Lupus. 2022;31(13):1606-1618. doi:10.1177/09612033221127569

  4. Reddington CL, Turnock ST, Conibear L, et al. Inequalities in Air Pollution Exposure and Attributable Mortality in a Low Carbon Future. Earth's Future. 2023;11(12). doi:https://doi.org/10.1029/2023EF003697

This post is not a substitute for professional advice. If you believe that you may be experiencing a medical emergency, please contact your primary care physician, or go to the nearest Emergency Room. Results from ongoing research are constantly evolving. This post contains information that was last updated in December 2025.


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