Cancer Risk: You may be increasing your cancer risk without knowing it: Doctor warns about micro-exposures and silent triggers |

When we think about cancer, we usually imagine the big, obvious risks, smoking, heavy radiation, strong family history. The scary stuff. The kind that comes with clear warnings. But doctors say that’s only part of the story. According to Dr Rajeev Vijayakumar, HOD & Sr Consultant – Medical Oncologist, Hemato Oncologist & BMT physician, Gleneagles BGS Hospital, Kengeri, Bengaluru, cancer risk often builds quietly, through small, everyday exposures we barely notice. A little pollution. Skipping sunscreen. Poor sleep. Too much processed food. None of it feels dramatic at the moment. And that’s exactly why it slips by us.“When most people think about cancer risk, the images are dramatic, cigarettes, radiation, a strong family history. The obvious threats. The ones that come with warning labels. What rarely gets discussed in everyday conversations are the smaller, repeated exposures that slip under the radar. Not intense enough to alarm. Not dramatic enough to feel dangerous. But present, daily, quietly accumulating,” Dr Rajeev Vijayakumar told TOI Health. “In oncology, risk is rarely about one catastrophic event. More often, it is about repetition.” The doctor shares the micro-exposure that we ignore.

The micro-exposures we don’t talk about

Air pollution is one example. Fine particulate matter (PM2.5), produced by vehicle exhaust, construction dust, and fuel combustion, is small enough to travel deep into lung tissue. Long-term exposure has been linked to lung cancer even in non-smokers. The risk per day feels negligible. Over years, it adds up.Ultraviolet radiation is another. Short bursts of harsh sun during beach holidays get attention. What tends to be underestimated is routine exposure, daily commutes, outdoor workouts, two-wheeler rides without protection. Repeated low-grade UV damage accumulates in skin cells, increasing the likelihood of DNA mutations over time.Dietary patterns tell a similar story. Processed meats, excess alcohol, chronically high sugar intake leading to obesity, none act overnight. But inflammation, insulin resistance, and hormonal shifts create an internal environment where abnormal cells are more likely to survive and multiply.Even sleep and circadian disruption are now being studied closely. Night-shift work and chronic sleep deprivation alter melatonin production and metabolic regulation. Emerging research suggests these disruptions may influence cancer risk, particularly in breast and colorectal cancers.The challenge with micro-exposures is psychological. Humans are wired to respond to visible danger, not subtle probability. A single cigarette feels risky; years of poor air quality feel abstract. A sunburn alarms; mild tanning does not.This does not mean living in fear of daily life. Cancer biology is influenced by genetics, environment, and chance. Not every exposure translates into disease. The body has robust repair systems, DNA repair enzymes, immune surveillance, and detoxification pathways. Most cellular damage is corrected before it becomes significant.

Micro-exposures becomes more meaningful when they are layered

For younger adults especially, the concept of prevention can feel distant, says Dr. Rajeev Kumar. Practical adjustments need not be extreme. Using sunscreen consistently. Improving indoor ventilation. Limiting processed meats. Moderating alcohol intake. Prioritising sleep as a physiological necessity, not a luxury. Choosing movement over prolonged sitting when possible, the expert added. None of these guarantee immunity. That is not how oncology works. But they meaningfully shift probabilities over time. Cancer risk is rarely shaped by one dramatic decision. More often, it reflects patterns repeated quietly over years. The exposures that do not feel urgent are often the ones worth noticing. The goal is not hyper-vigilance. It is awareness — and the understanding that small, sustained choices can alter long-term trajectories more than most people realise, Dr. Rajeev Kumar said.Medical experts consulted This article includes expert inputs shared with TOI Health by: Dr Rajeev Vijayakumar, HOD & Sr Consultant – Medical Oncologist, Hemato Oncologist & BMT physician, Gleneagles BGS Hospital, Kengeri, BengaluruInputs were used to explain the risk of micro-exposures like radiation, erratic sleep cycle, etc on cancer risk.