Science Magazine - The link between air pollution and dementia remains controversial—even its proponents warn that more research is needed to confirm a causal connection and work out just how the particles might enter the brain and make mischief there. But a growing number of epidemiological studies from around the world, new findings from animal models and human brain imaging studies, and increasingly sophisticated techniques for modeling PM2.5 exposures have raised alarms. Indeed, in an 11-year epidemiological study to be published next week in Translational Psychiatry, USC researchers will report that living in places with PM2.5 exposures higher than the Environmental Protection Agency’s standard of 12 µg/m3 nearly doubled dementia risk in older women. If the finding holds up in the general population, air pollution could account for roughly 21% of dementia cases worldwide, says the study’s senior author, epidemiologist Jiu-Chiuan Chen of the Keck School of Medicine at USC.
The field is “very, very young,” cautions Michelle Block, a neuroscientist at Indiana University in Indianapolis. Nonetheless, it’s a “hugely exciting time” to study the connections between pollution and the brain, she says. And if real, the air pollution connection would give public health experts a tool for sharply lowering Alzheimer’s risks—a welcome prospect for a disease that is so devastating and that, for now, remains untreatable.