The Big Problem with Tiny Plastics
Neuroscientist David Davis’s research on the impact of plastics on cognition stars in an Emmy-winning documentary
By Joey Garcia
Illustration by Federico Gastaldi
I
n the PBS documentary We’re All Plastic People Now, scientists delve into the impact of plastics in the human body. While the environmental harm associated with plastic is no secret, scientists in the documentary discussed outcomes related to the foods we eat, the water we drink and the air we breathe. Among the notable researchers featured in the film, which won a 2023 Suncoast Emmy and was accepted into the prestigious 2024 Santa Fe Film Festival, is David Davis, Ph.D., research assistant professor of neurology and associate director of the Brain Endowment Bank at the Miller School.
“Plastics are a growing public health concern because of their abundance in the environment and their ability to break down into smaller particles, increasing their toxicity,” Dr. Davis said. “We are on the cutting edge of knowledge regarding the effects of nanoplastics exposure on our cognition.”
At the Brain Endowment Bank, Dr. Davis and colleagues are investigating whether airborne plastic nanoparticles can enter the brain through the olfactory nerve, which spans from our nasal epithelium into regions of the brain involved in learning and memory. If particles can enter the nasal epithelium and gain access to this nerve, they can travel to and build up in the brain, causing toxicity. Damage to this nerve is one of the earliest signs of Alzheimer’s and Parkinson’s diseases.
“It is a great feeling to know the basic research we are doing in the Department of Neurology and in the Brain Endowment Bank will reach a broad audience,” Dr. Davis said. “This is one of the most critical environmental issues we face, and we urgently need a resolution. The bulk weight of plastics in our environment is increasing. Plastic debris can be found on mountaintops and in the deepest regions of the ocean, yet we know little about plastics and their impact on our health.”
The documentary presented testing results from blood samples showing an individual can have 80 or more plastic-related compounds circulating in their blood.
“Our goal is to see if the same holds true for the brain,” Dr. Davis said. “We selected well-characterized autopsy brain samples from healthy and cognitively impaired brain donors for similar testing. We anticipate publishing the findings from this research study later this year.” 
