UW study links fine particulate air pollution to dementia

Air pollution is often associated with respiratory illness. But a new University of Washington study adds to a growing body of evidence that links air pollution to greater risk for dementia.

Researchers reached that conclusion using data from two existing Seattle projects. One has been measuring air pollution in the region since the 1970s. Another, started in 1994, monitors cognitive changes in older adults.

Lead author Rachel Shaffer says when a person in the second study was diagnosed with dementia, they looked at air pollution in the area where they were living for the past 10 years. She found that even a small increase in fine particle pollution was associated with a 16% increased risk of dementia.

“Our study was focused on fine particulate matter that’s less than 2.5 micrometers in diameter,” Shaffer said. “It’s about 30 times smaller than a single strand of hair.”

The size category is relevant.

“They’re so small you can more penetrate easily the body,” she explained.

The particles could be made up of dust, dirt, or metal.

While wildfire smoke tends to get a lot of attention, microscopic pollution that we can’t see is affecting our bodies, too.

There are no effective treatments for dementia. Shaffer hopes the study can help change policy for air pollution standards. In the meantime, there are a few ways people can reduce their risks.

“More and more people are investing in home air purifiers and I think that is a good thing to use perhaps year round especially if you live near busy roads.”

She also recommends adjusting outdoor activities based on the air quality. And wearing masks.

The study is published in the journal Environmental Health Perspectives.