Air pollution in Delhi-NCR may be silently triggering rheumatoid arthritis (RA), one of the most debilitating autoimmune diseases worldwide, experts said on Thursday. At the 40th annual conference of the Indian Rheumatology Association (IRACON 2025) being held from October 9 to 12 at the Yashobhoomi in Dwarka, leading rheumatologists cited evidence that toxic air and PM2.5 pollution could be fuelling a surge in rheumatoid arthritis cases across Delhi-NCR. The experts pointed out that autoimmune diseases like RA - in which the immune system attacks the body's own tissues, especially the joints, causing persistent pain, swelling, stiffness, and disability - are life-long conditions with no permanent cure available. The symptoms can only be managed. Traditionally linked to genetics and immune system dysfunction, RA is now increasingly being associated with environmental triggers such as air pollution. Current estimates suggest that RA already affects around 1% of India's adult population. But with pollution adding fuel to the fire, the prevalence of RA is expected to rise in Delhi-NCR and similar polluted regions, experts said. Dr Uma Kumar, Head of Rheumatology at AIIMS Delhi, said, "When pollution levels are high, the patients who do well otherwise, their condition also worsen. We are observing a rise in RA cases in patients living in polluted areas with no family history or genetic predisposition to autoimmune disease." She added that most of these patients are in the 20-50 age group. “This is a public health emergency we can no longer ignore,” she said. Dr Pulin Gupta, Professor and Rheumatologist at Dr Ram Manohar Lohia Hospital, said, “What we are witnessing is not just a increase in cases of RA but these cases are also more severe. Reduced green spaces in urban areas are worsening the problem, depriving residents of protective environmental buffers." He added, "Studies show strong associations between exposure to PM2.5, nitrogen oxides, and ozone with increased risk of RA cases, especially in genetically susceptible individuals. Living near busy roads, which means constant traffic-related pollution, has also been linked to higher RA risk." He said the findings are not just theoretical. “A landmark study published in the European Medical Journal (2025) provided strong genetic evidence connecting air pollution to autoimmune diseases, including RA. Using a two-sample Mendelian randomisation approach, the study identified significant causal links between common pollutants and immune system dysfunction, highlighting environmental damage as a crucial driver in the rise of these diseases,” he added. Dr Pulin said Delhi being one of the top 10 most polluted cities in the world, has emerged as a hotbed of concern. Recent studies in Europe, China, and now in India, suggest that exposure to PM2.5 - the dangerous fine particulate matter that penetrates deep into the lungs - may be linked not only to heart and lung diseases, but also to autoimmune disorders like RA. Dr Neeraj Jain, Scientific Chairman and Vice Chairman, Department of Rheumatology at Sir Ganga Ram Hospital, said, “Pollution is rewriting that narrative. turning healthy individuals into patients. The fact that young people with no family history are developing RA should set alarm bells ringing." He added that research conducted in China showed that long-term exposure to PM2.5 was associated with a 12%-18% increased risk of developing RA. "European cohorts similarly reported that people living in highly polluted cities had significantly higher morbidity related to autoimmune disorders. These findings mirror what doctors are now observing. with Delhi residents facing a double blow of respiratory distress and autoimmune flare-ups," he added.
