Risk of Parkinson’s Has a ‘Strong Association’ With Where You Live

Living in an area with higher air pollution could significantly increase a person’s risk of developing Parkinson’s disease, a new study shows.

After analyzing data from around 22 million Medicare recipients, researchers identified nearly 90,000 people with a Parkinson’s diagnosis, many of whom had something in common — they lived in an area with higher levels of particulate matter, or pollution, in the air. 

According to the research, published Monday in the journal Neurology, people who lived in areas with more air pollution were found to have a 56% greater risk of developing Parkinson’s in comparison to those who lived in regions with less pollution.

“Previous studies have shown fine particulate matter to cause inflammation in the brain, a known mechanism by which Parkinson’s disease could develop,” Brittany Krzyzanowski, Ph.D., a researcher at Barrow Neurological Institute, said in a release on the study. "Using state-of-the-art geospatial analytical techniques, we were, for the first time, able to confirm a strong nationwide association between incident Parkinson’s disease and fine particulate matter in the U.S.”

Fine particulate matter, or PM2.5 got significant attention over the summer when smoke from the wildfires in Canada began to blanket parts of the U.S. The negative impact fine particulate matter has on our air quality has been growing in recent years, and experts have suggested that an uptick in wildfires could be to blame.

These particles are small enough to be inhaled and can cause irritation of the eyes, nose, throat and lungs in the short-term, and have been linked with conditions like asthma, dementia, cardiovascular disease — and now Parkinson’s disease — in the long-term.

Parkinson’s disease is a neurological condition that causes uncontrollable movements, tremors, stiffness and rigidity. People who have the condition often struggle with balance and coordination, and their symptoms typically progress over time.

Experts were able to hone in on several regions they described as Parkinson’s hotspots, where the diagnosis was more prevalent, as was the presence of air pollution. The Mississippi-Ohio River Valley, central North Dakota, parts of Texas, Kansas, eastern Michigan and Florida were all found to have higher rates of Parkinson’s, while the western half of the country was found to have fewer residents with the condition.

This could be, in part, due to the type of pollution people are exposed to, although this has not yet been studied extensively. The authors point out that the Mississippi-Ohio River Valley region is crawling with networks of roads that increase traffic in the area. Similarly, many of these areas are considered part of the Rust Belt, home of the industrial boom of the mid-1900s.

“This means that the pollution in these areas may contain more combustion particles from traffic and heavy metals from manufacturing which have been linked to cell death in the part of the brain involved in Parkinson’s disease,” Dr. Krzyzanowski said.

The authors are hopeful that their findings will offer incentive to further investigate the role of air pollution in Parkinson’s, as prior research has instead focused on pesticides.