It is well-known that smoking or tobacco addiction is a major culprit behind lung cancer. However, non smokers are also not safe from the deadly disease. Internal medicine expert Dr Priyam Bordoloi shared one common habit which makes non smokers more susceptible to lung cancer. Highlighting this issue on X, internal medicine specialist Dr. Priyam Bordoloi drew attention to a lesser-known everyday exposure that could raise lung cancer risk among lifelong non-smokers. He challenged users with a multiple-choice question, asking them to identify a common daily habit that may contribute to the disease despite never using tobacco.The options included:Regularly burning scented candles indoorsCooking at very high temperatures without using a kitchen exhaust or proper ventilationFrequently burning mosquito coilsUsing aerosol-based room fresheners inside the homeHe also revealed which habit can make non smokers more vulnerable to cancer - and it’s cooking without an exhaust. "You don't need to smoke a single cigarette to be at risk for lung cancer. In fact, one of the biggest silent dangers is hiding right in your kitchen..." he said. Why Cooking Fumes Can Be HarmfulCooking methods such as deep-frying, stir-frying, or searing food over very high heat can cause cooking oils to decompose and release airborne pollutants. In kitchens without proper ventilation, such as an exhaust fan, chimney, or open windows, these fumes accumulate indoors, increasing the amount of polluted air that occupants inhale during meal preparation.— DocPriyamMD (@DocPriyamMD) Harmful Chemicals Released During High-Heat CookingThe smoke produced from overheated cooking oils contains tiny toxic compounds, including polycyclic aromatic hydrocarbons (PAHs) and reactive chemicals known as aldehydes, such as acrolein. These substances are generated when oils are exposed to very high temperatures and become suspended in the air as fine particles and gases.Long-Term Exposure May Damage Lung CellsRepeatedly breathing in cooking fumes over many years can gradually harm the cells lining the respiratory tract. Scientists believe that prolonged exposure to these pollutants may damage cellular DNA, increasing the likelihood of genetic mutations that can contribute to the development of lung cancer.Why Non-Smokers May Also Be at RiskAccording to Dr. Bordoloi, this type of long-term exposure helps explain why lung cancer is sometimes diagnosed in people who have never smoked. The risk may be greater for individuals—particularly women in some households—who spend extended periods cooking in kitchens with inadequate ventilation, allowing smoke and oil fumes to build up over time.Simple Steps to Reduce ExposureImproving kitchen ventilation is one of the most effective ways to lower exposure to cooking-related air pollution. Switching on an exhaust fan or chimney before cooking, keeping windows open to improve airflow, and preventing cooking smoke from lingering indoors can significantly reduce the amount of harmful fumes inhaled and help protect long-term lung health.