Top 5 Lung Cancer Causes In Non-Smokers

Medically reviewed by Dr Johann Tang, Senior Consultant Radiation Oncologist

Smoking is by far the leading cause of lung cancer. However, it is not associated with every case of lung cancer. In fact, non-smokers make up only three in ten lung cancer patients in Singapore, according to a study by the National Cancer Centre Singapore (NCCS). Let our cancer doctor, Dr Johann Tang, share more about the various lung cancer risk factors so that you can learn how to minimise your risk of developing this disease.

Risk #1: Air Pollution

Exposure to high levels of air pollution may trigger DNA damage, causing tumours to develop, thus leading to lung cancer. Your risk increases the longer you are exposed to environmental pollutants. Therefore, it is imperative to take precautions to minimise exposure, such as wearing a mask outdoors. That is especially crucial during haze season when air contaminants caused primarily by slash-and-burn land clearing in neighbouring nations spread to Singapore.

Risk #2: Occupational Hazards

Specific occupations or work environments can expose a person to lung cancer-causing agents. For instance, welding fumes contain carcinogens like fluorides, metallic oxides, and silicates. Meanwhile, benzene is a natural part of mixtures such as crude oil and gasoline, which are commonly found in the oil and gas industry. 

After prolonged exposure, these carcinogens can eventually build up inside your lungs, causing your cells to mutate and develop cancer. They can also reside in your system for a period of time after exposure. If you are regularly exposed to these elements as part of your job, ensure you wear the proper personal protective equipment (PPE) during work. You may also consider speaking with your doctor about undergoing a lung cancer test screening.

Risk #3: Secondhand Smoke

Smoking is not only harmful to a smoker’s body. The secondhand smoke from the cigarette can also adversely affect you or your loved ones. The chemicals can linger and leave a residue on your bedding, clothes, upholstery, and other areas in the home. This long-term exposure to the smoke and residual chemicals can increase lung cancer risk.

If you live with someone who smokes, consider persuading your partner or family member to stop smoking indoors or, even better, quit altogether. When visiting a family member or friend who smokes, you can arrange for a gathering outside whenever possible to minimise smoke contact.

Risk #4: Radon Exposure

Radon is a naturally occurring, odourless gas produced by the radioactive decay of radium and is often present in rock, soil, and building materials. It is part of the natural background radiation we are exposed to daily. The gas can seep through foundation crevices and attach to clothing, upholstery, walls, and other interior surfaces, causing ongoing exposure.

Fortunately, exposure to dangerous concentrations of radon in Singapore tends to be rare, as most Singaporeans live in high-rise apartments. Nevertheless, you can reduce your risk by having your home tested and treated for radon and closing any cracks in floors or walls with sealants. Increasing airflow into your living space can also reduce radon levels.

Risk #5: Genetic Mutations

Lung cancer can develop as a result of somatic mutations – an alteration in DNA that occurs after conception. Instead of being passed down through the family, these genetic changes happen during a person’s lifetime and are only present in specific cells in the lung. Somatic mutations in the EGFR, KRAS, and TP53 genes are common in lung cancer patients. While some of these changes pertain to smoking, others can occur in non-smokers.

Learn More: Understanding The Different Types And Stages Of Lung Cancer

If you suspect you might be at risk of developing lung cancer based on the factors our cancer doctor shared, consider going for a cancer screening. It can help detect and diagnose lung cancer early, allowing you to undergo lung cancer treatment at the earliest possible stage, thus improving your chances of recovery.

With over two decades of experience in the medical field, Dr Johann Tang is well-versed in treating lung cancer patients. If you wish to learn more about your cancer treatment options or get a second opinion on a diagnosis, contact our clinic to schedule an appointment with our cancer doctor today.