The effects are worse than years of aging
The part of the brain that stores general knowledge about the world
Air pollution has long been linked to lung disease, heart problems and premature death. Now, researchers have found further evidence that the air people breathe may also affect how well their brains function as they age. A new study from UC Davis Health and Kaiser Permanente suggests that long-term exposure to fine particulate matter may damage an important type of memory that people rely on every day.
The study focused on particles known as PM2.5. They are extremely small—about 30 times smaller than the width of a human hair—and can penetrate deep into the lungs and enter the bloodstream. Scientists have been studying how PM2.5 affects physical health for years, but increasing attention is being paid to its effects on the brain.
Researchers found that people who lived in areas with higher levels of PM2.5 for many years performed worse on tests of semantic memory. Semantic memory is the part of memory that stores general knowledge about the world. It includes facts, vocabulary, word meanings, object names, and information that people learn throughout their lives. This type of memory helps people communicate, understand conversations, and perform everyday tasks. The results were published in the journal Alzheimer’s & Dementia: Behavior & Socioeconomics of Aging.
The researchers analyzed data from 740 people between the ages of 53 and 94. They calculated each participant’s exposure to PM2.5 by examining air pollution levels at their addresses over five, ten, and seventeen years. The team then compared pollution exposure with scores on various cognitive tests.
The results showed a clear trend. Participants exposed to higher levels of PM2.5 over many years performed worse on tests of semantic memory. This association remained even after the researchers accounted for factors such as age, education, income and marital status. One of the most significant findings was the magnitude of the effect. The researchers estimated that the impact of long-term exposure to PM2.5 on semantic memory was greater than what would typically be expected from ten years of aging.
Illustrative photo: pexels-shvets-production-7545335
