The closer you live to a major roadway, the greater your risk of stroke, according to a recent study that assessed the impact of air pollution on the brain.
Published in the medical journal Stroke, this study analyzed data from the Framingham Offspring Study, which is part of one of the longest running research studies in the United States. Using MRI (magnetic resonance imaging) scans and U.S. census data, researchers hoped to investigate the relationship between long-term exposure to air pollution and stroke risk. While studies have linked air pollution to increased risk for conditions like stroke and dementia, less is known about how it impacts brain structure itself.
A total of 943 older adults were included in the study, all of whom were at least 60 years old and had no history of dementia or stroke. During the study period, participants underwent an MRI, which provides detailed images of the brain and is especially useful in diagnosing stroke—a condition that occurs when blood flow to the brain stops. Using U.S. census data, researchers also calculated participants’ proximity to major roadways and their exposure to a type of air pollution called fine particulate matter. Fine particulate matter are particles found in the air that are so small they can be inhaled and go deep into the lungs, having an adverse effect on health.
After analysis, researchers found that higher levels of exposure to air pollution were linked to smaller brain size—a sign of many diseases that affect the brain. The more exposure subjects had to air pollution, the greater their risk of “silent” strokes, which cause damage to the brain but do not cause any outward symptoms. The good news is that the further subjects lived from a major roadway, the healthier their brains were.
This study highlights the negative impact that long-term exposure to air pollution can have on our health. As authors explain, their findings suggest that air pollution can cause the brain to age more quickly, even in adults free of dementia and stroke.
Fine particulate matter can come from sources like cars and power plants, and it’s important to minimize exposure to this dangerous type of air pollution as much as possible. Experts advise against walking or exercising in areas with major traffic and spending time outdoors during highly polluted periods, like rush hour. Additional information on air quality is also publically available through resources like AIRNOW, which can be used to further reduce exposure to air pollution.