A new study has uncovered alarming evidence that air pollution, particularly fine particulate matter (PM2.5), is not only linked to lung cancer but also to a higher risk of death from several other types of cancer, including breast, liver, and pancreatic cancer.
Conducted by researchers from Hong Kong and Birmingham, UK, the study examined the long-term effects of PM2.5 exposure—a tiny pollutant found in the air from sources like transportation and power plants. These particles are so small (less than 2.5 micrometers) that they can penetrate deep into the lungs, making them especially harmful to health. The study tracked the health outcomes of 66,280 Hong Kong residents, all aged 65 or older, over a period of more than a decade, from 1998 to 2011.
The findings were striking: for every 10 µg/m3 increase in PM2.5 exposure, the risk of dying from any cancer shot up by 22%. But the risks were even more severe for specific cancers:
- The mortality risk for cancers of the upper digestive tract rose by a staggering 42%.
- For cancers in the liver, bile ducts, gall bladder, and pancreas, the mortality risk increased by 35%.
- Women faced an 80% higher risk of dying from breast cancer.
- Lung cancer mortality also spiked by 36%.
These findings highlight just how dangerous air pollution can be, with long-term exposure to PM2.5 emerging as a deadly environmental factor contributing to cancer deaths.
So, why does pollution have such a profound impact on cancer? Researchers suggest several possible mechanisms. Pollution might damage the body’s ability to repair DNA, alter immune responses, or even spark inflammation that fuels the growth of blood vessels to feed tumors. In the case of digestive cancers, pollution could also affect the microbiota in the gut, influencing cancer development.
Dr. G. Neil Thomas, a lead author of the study, emphasized that while the findings are eye-opening, more research is needed to confirm whether other countries, especially urban areas, face similar risks. He urged policymakers to take action, pointing out that reducing PM2.5 levels must be a priority for public health. "Air pollution remains a clear, modifiable public health concern," he said.
Thuan Quoc Thach, the other lead author, added that while PM2.5 is a major contributor to the issue, it's only one component of air pollution. He cautioned that other factors, like diet and exercise, might also play a significant role in cancer development, and that future research should consider these variables.
This study reinforces earlier conclusions from the International Agency for Research on Cancer (IARC), which has long recognized outdoor air pollution, including PM2.5, as a cancer-causing agent. With these new findings, the urgency for cleaner air is clearer than ever—air pollution is not just an environmental issue, it’s a life-and-death health concern that we can no longer ignore.