A new global analysis has found that there is an increase in lung cancer diagnoses among people who have never smoked, raising particular concerns for countries like India where severe air pollution affects multiple states, especially during winter months.

According to a study published on Tuesday in The Lancet Respiratory Medicine journal, adenocarcinoma has emerged as the predominant form among four main lung cancer subtypes, accounting for 53%-70% of cases in never-smokers worldwide.

The research estimates that in 2022, ambient particulate matter pollution was responsible for 114,486 adenocarcinoma cases in men and 80,378 cases in women globally.

A new global analysis has found that there is an increase in lung cancer diagnoses among people who have never smoked, raising particular concerns for countries like India where severe air pollution affects multiple states, especially during winter months.

According to a study published on Tuesday in The Lancet Respiratory Medicine journal, adenocarcinoma has emerged as the predominant form among four main lung cancer subtypes, accounting for 53%-70% of cases in never-smokers worldwide.

The research estimates that in 2022, ambient particulate matter pollution was responsible for 114,486 adenocarcinoma cases in men and 80,378 cases in women globally.

The suggests a growing link between air pollution and lung cancer risk particularly in eastern Asia and China.

The research shows that lung cancer continues to be the leading cause of cancer-related morbidity globally, with approximately 2.5 million diagnoses (including smokers0 in 2022. While men still represent the majority of cases with 1.6 million new diagnoses in 2022, the gender gap is narrowing, as nearly 910,000 women were diagnosed during the same period.

“These shifts can be attributed to the changing patterns of cigarette smoking over the past several decades, including smoking prevalence, tobacco type, smoking habit, smoking intensity, and smoking initiation and cessation,” the study reported.

As smoking rates decline globally, researchers note that lung cancer in never-smokers has become the fifth leading cause of cancer-related mortality worldwide.

The researchers emphasise the importance of continued monitoring of lung cancer risk patterns and call for additional studies to identify potential causal factors, particularly air pollution, in populations where smoking is not the primary cause.

A separate study published in The Lancet Planetary Health last year found that long-term exposure to PM2.5 pollution above the WHO’s recommended annual average of 5 μg/m³ may be associated with 1.5 million deaths annually in India. Both urban and rural areas in India face high PM2.5 concentrations throughout the year.

Dr. GC Khilnani, former head of pulmonology at AIIMS-Delhi, warns, “It has been well-established that long-term exposure to severely polluted air is as bad as smoking, may be worse, even for absolutely healthy persons. Most of those living in such environment will have compromised lung health.”