Lung cancer, long regarded as a disease predominantly affecting tobacco users, is now witnessing a troubling shift, with a growing number of cases being reported among non-smokers. This changing pattern has prompted fresh scientific inquiry into environmental risk factors, particularly air pollution.
A team of top oncologists from the All India Institute of Medical Sciences (AIIMS), Delhi, has initiated AIRCARE (Air Pollution and Cancer Research Ecosystem), a multi-year study aimed at examining whether prolonged exposure to polluted air, especially fine particulate matter ($PM_{2.5}$), could be a significant contributor to lung cancer in individuals with no history of smoking.
The study, spanning three years, is expected to track patient profiles, exposure histories, and clinical outcomes to better understand how and to what extent pollution contributes to cancer risk. Researchers are particularly focused on identifying biomarkers that could establish a clearer causal pathway between polluted air and tumor development.
Led by Dr. Abhishek Shankar, Assistant Professor of Radiation Oncology, with Dr. Sunil Kumar, Professor & Head of Surgical Oncology; Dr. Rambha Pandey, Professor of Radiation Oncology; and Dr. Sachidanand Jee Bharati, Professor of Onco-Anaesthesia & Palliative Medicine, the study is said to be the first scientific study of its kind in India. Other researchers include Dr. Chandra Prakash Prasad, Additional Professor of Medical Oncology (Lab); Dr. Mayank Singh, Additional Professor of Medical Oncology (Lab); Dr. Ashutosh Misra, Associate Professor of Surgical Oncology; and Dr. Ashish Datt Upadhyaya, Biostatistics, CRU at AIIMS Delhi.
"Apart from this, it will also see the multiplicative interaction of air pollution with other risk factors of lung cancer," said Dr. Shankar.
Highlighting the gravity of the issue, Dr. Sunil Kumar noted that India has some of the world’s most polluted cities, making it essential to closely examine the long-term health effects of pollution. He pointed out that lung cancer remains one of the most common cancers among men in the country, while cases among non-smoking women and younger individuals are also on the rise.
Although pollution is increasingly being linked to lung cancer, he said more India-specific data is required. He expressed concern that the disease, once largely associated with tobacco use, is now being detected more frequently among non-smokers.
The AIRCARE study will analyze 1,615 lung cancer patients along with an equal number of control subjects drawn from their family members across the Delhi-NCR region. It combines both clinical and non-clinical approaches to better understand the impact of prolonged exposure to $PM_{2.5}$ across different population groups and socioeconomic backgrounds, added Dr. Shankar.
A key component of the research involves identifying a distinct genetic signature among Indians exposed to high pollution levels. The aim is to determine whether early genetic changes triggered by pollution could eventually lead to lung cancer.
Using the findings, researchers plan to develop a risk-based screening model tailored to Indian conditions, incorporating both clinical and molecular data. The study will also help identify vulnerable groups who may be at a higher risk of developing the disease.
Dr. Kumar noted that, “If pollution is contributing significantly to lung cancer, it has major policy and preventive implications.”
Globally, health agencies such as the World Health Organization (WHO) have already classified outdoor air pollution as a carcinogen. However, region-specific, long-term cohort data—especially from highly polluted urban centers like Delhi—remain limited.
