Dear EarthTalk: Does exposure to air pollution cause “brain fog”?
—Mark H., Raleigh, NC
Exposure to air pollution has long been connected to respiratory and cardiovascular issues. More recently, researchers have found evidence that it may also impair brain function. Studies suggest air pollution is associated with cognitive decline, memory problems and short-term cognitive performance—what many call brain fog—accentuating concerns about the effects of polluted air on mental clarity and brain health.
Air pollution is a combination of harmful gases and particles, such as fine particulate matter (PM2.5), carbon monoxide and nitrogen dioxide. These pollutants, frequently released by vehicles, industries and wildfires, can enter the bloodstream and access the brain. Research shows that high levels of air pollution are linked to heightened brain inflammation, interrupted neural connections and diminished oxygen supply, which may all lead to cognitive impairment. A 2025 study in Nature discovered that extended exposure to air pollution may hasten cognitive deterioration, especially among older individuals.
People exposed to elevated pollution levels usually experience symptoms like trouble focusing, memory issues and mental exhaustion. Dr. Caleb Finch at the University of Southern California, states, “The aging brain is vulnerable to air pollution.” His studies show that exposure to pollutants might elevate the risk of neurodegenerative conditions like Alzheimer’s disease. Kids and young individuals could also be in danger. The growing brain is especially sensitive to environmental toxins, and certain studies indicate that children subjected to elevated pollution levels might encounter decreased IQ scores and attention issues…