While researchers have theorized for decades that air pollution is probably a contributing factor to dementia, numerous studies in recent years have cemented this theory as extremely likely and borderline conclusive, despite the inability to construct a controlled human experiment testing the link between the two, according to an article from Mother Jones republished by Wired.
“I have no hesitation whatsoever to say that air pollution causes dementia,” said University of Southern California Air Pollution and Brain Disease research network leader Caleb Finch. And, more broadly speaking, Finch said that “air pollution is just as bad as cigarette smoke.”
The growing evidence supporting the link between worsened cognitive functions and air pollution comes in a period during which air quality is declining in many U.S. cities and the Trump administration is continuing to strike down environmental regulations.
In one of the most significant studies, published in 2018, researchers followed 130,000 older adults that lived in London for an extended period of time. They found that individuals that frequently inhaled higher levels of air pollution had a significantly higher likelihood of developing Alzheimer’s disease, the most common form of dementia, than their peers with otherwise equal demographic characteristics.
And, overall, Londoners that were exposed to the most air pollution had a roughly 50 percent higher likelihood of developing Alzheimer’s during the study’s time frame than those exposed to the least air pollution. The findings were a replication of the results of a previous study in Taiwan, where levels of air pollution are notably higher.