More on the links between air pollution and brain disease

A new article in the prestigious journal, PNAS, reviews the latest research on the connections between air pollution and cognitive dysfunction.

The focus of the latest research is the role of fine particulate matter (PM2.5), which is one of the pollutants produced by gas-powered leaf blowers. Because particulate matter is less than 2.5 micrometers in diameter, i.e. really really small, it not only stays airborne for a long time, but is also capable of penetrating the blood-brain barrier. Even worse is that PM2.5 attaches to other pollutants — such as dioxins, lead, and mercury – carrying them directly to the brain, where they damage neurons and immune cells.

“PM is simply acting as a vector,” says Masashi Kitazawa, a molecular neuropathologist at the University of California, Irvine. “It might be a number of chemicals that get into the brain and act in different ways to cause damage.”

Some of the recent studies suggest that air pollution causes chronic brain inflammation, which was observed to induce behavioral symptoms characteristic of autism, schizophrenia, and other cognitive dysfunction in newborn mice. Researchers also observed reduced white matter in the brain after short-term exposure to air pollution. In older mice, researchers observed deficits in learning and memory.

Notably, in these studies, the concentration of particulate matter to which the mice were exposed was comparable to the amount found in high traffic areas in many cities, making the connection between air pollution and brain disease both very real and extremely troubling. One scientist working on the research even stated that he didn’t believe the results at first, because “the implications were too frightening.”

And the connections haven’t been limited to just non-human animals either. Recent research “identified neuroinflammation, brain structure changes, cognitive deficits, and Alzheimer’s-like pathologies in apparently healthy children living in Mexico City, compared with a group of similar children in a less polluted city.” Another study on a US population found that living in an area with high levels of particulate matter almost doubled the risk of dementia for women and nearly tripled the risk for women with a genetic predisposition for Alzheimer’s disease.

It’s time we get serious about limiting unnecessary exposure to air pollution in our communities. Tell lawmakers to ban gas-powered leaf blowers from May through September.

Read the full article here: https://www.pnas.org/content/early/2020/06/02/2008940117