Lung cancer in non-smokers: Health risks of air pollution, second- hand smoking, other dangers

Apart from smoking, which is associated with lung cancer, a growing impact of environmental factors, such as air pollution, radon exposure, and workplace hazards are increasingly recognised as major contributors to the development of lung cancer in non-smokers. The symptoms of lung cancer in non-smokers can often be subtle and may not appear until the cancer has progressed. Common signs include persistent coughing, chest pain, shortness of breath, hoarseness, fatigue, weight loss, and coughing up blood. Since these symptoms overlap with other conditions, lung cancer can sometimes be misdiagnosed in its early stages.

The causes of lung cancer in non-smokers are diverse, with environmental factors playing a significant role, says Dr Bernard J. Park, MD, a thoracic surgeon at Memorial Sloan Kettering Cancer Centre, New York. “Exposure to pollutants, hazardous chemicals, and carcinogenic substances can damage lung cells over time, leading to mutations and cancer development,” he adds.

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Dr Park highlights the dangers of lung cancer in non-smokers: 

• Air pollution: Prolonged exposure to air pollutants, especially fine particulate matter (PM2.5), is one of the primary environmental risk factors for lung cancer. In urban areas with high levels of industrial emissions and vehicle exhaust, the lungs are continually exposed to harmful chemicals that can increase the likelihood of cancer.

• Radon exposure: Radon is a radioactive gas that can accumulate in homes, especially in areas with uranium-rich soil. Radon is the second leading cause of lung cancer in non-smokers, after smoking itself. It is colorless, odorless, and can remain undetected until it causes serious harm, making it a silent but dangerous environmental threat.

• Second-hand smoke: Even non-smokers who are regularly exposed to second-hand smoke face an increased risk of developing lung cancer. This exposure is particularly harmful in enclosed spaces such as homes, workplaces, or restaurants, where the concentration of toxic smoke particles is high.

• Exposure to harmful substances: Certain industries, such as mining, construction, and chemical production, expose workers to carcinogens like asbestos, benzene, and silica dust. Non-smokers in these fields are at a heightened risk of lung cancer due to long-term exposure to harmful substances in the workplace.

• Chemicals in household products: Many household products, from cleaning agents to air fresheners, contain volatile organic compounds (VOCs) that can irritate the lungs and contribute to cancer development. Over time, repeated exposure to these chemicals can increase the risk of lung cancer.