A major new study involving nearly 28 million people has found that long term exposure to fine particle air pollution and smog greatly raises the risk of Alzheimer’s disease. The findings suggest that residents of Lahore may face a higher risk because of the city’s severe air pollution.
The research was carried out at Emory University and published in PLOS Medicine. It analysed health data collected over almost twenty years.
Scientists examined whether polluted air damages the brain indirectly by triggering conditions such as high blood pressure, stroke, and depression, which are already known to be linked with dementia.
Results showed that these health conditions accounted for less than 5 percent of the link between air pollution and Alzheimer’s disease. This indicates that more than 95 percent of the increased risk is likely caused directly by breathing polluted air.
The study also observed that the risk of Alzheimer’s steadily increased as levels of PM2.5 rose. PM2.5 refers to tiny particles released from sources like vehicle emissions, power plants, wildfires, and fuel burning, all of which are common contributors to pollution in Lahore.
Although PM2.5 is associated with high blood pressure, stroke and depression, treating these illnesses does not remove the additional dementia risk tied to polluted air. Lowering exposure to PM2.5 remains essential to reduce overall risk.
While the elevated risk was seen across the population, researchers found that people who had previously suffered a stroke were particularly vulnerable. The exact reason for this heightened sensitivity is still unclear.
The study monitored nearly three million Alzheimer’s cases, adding strong evidence that cleaner air could help in preventing dementia. The results are especially important for those living in low income areas where exposure to PM2.5 tends to be higher.
Researchers concluded that stricter air quality standards at the community and national levels could significantly reduce Alzheimer’s cases. However, they cautioned that no single step can completely prevent the disease, as both genetic and environmental factors play a role in determining risk.