Air Pollution in Santiago May Increase Risk of Alzheimer’s and Affect Memory, Study Finds

A new study published in Science of The Total Environment analyzed how Santiago’s air pollution affects the brain and memory. The research was led by Drs. Brigitte van Zundert and Lorena Varela-Nallar, scientists from the Institute of Biomedical Sciences at the School of Medicine of Universidad Andrés Bello (UNAB) and the Núcleo Milenio for Neuroepigenetics and Plasticity (EpiNeuro).

“We analyzed how air pollution — caused by traffic, industrial activity, and fuel combustion — impacts the brain and memory,” explained Dr. van Zundert. “We used an experimental model exposed to environmental pollution from central Santiago, an area with a high concentration of airborne particles.”

After seven months of exposure, “we observed that pollution negatively affected memory, increased anxiety, and triggered behaviors related to depression and reduced social interaction,” added Dr. Varela-Nallar.

At the cellular level, air pollution triggered an inflammatory response in neurons and other brain cells — particularly in the hippocampus, a region that plays a key role in memory.

“At the molecular level, we discovered that pollution induces changes in epigenetic markers associated with DNA,” said the researchers. “These are chemical modifications that regulate whether genes are activated or silenced — they act like switches that control gene expression. When these markers are altered or reduced, genes may be activated inappropriately, leading to damage and impaired brain function.”

Link to Neurodegenerative Diseases

One of the most significant findings of the study is the potential link between these changes and emotional or memory issues, which — over the long term — could raise the risk of neurodegenerative diseases like Alzheimer’s.

“In fact, in a previous study in our lab, we analyzed brain tissue samples from young adults in Mexico City — a city with pollution levels similar to Santiago — and found both DNA damage and altered epigenetic markers,” said Dr. Varela-Nallar. “We also detected hyperphosphorylated tau protein and beta-amyloid plaques — both hallmark signs of Alzheimer’s disease.”

In summary, living in areas with high levels of air pollution may increase the risk of cognitive and memory problems over time. However, there is a positive note — 2025 marked one of the three winters with the best air quality in the Santiago Metropolitan Region, meaning lower exposure for residents this year.

To help reduce air pollution, experts recommend practical steps such as using electric public transportation, walking, or biking instead of relying on private vehicles to cut down on emissions.