
Air pollution is affecting the health of our lungs, our hearts, and even our brains. New studies show that children and young adults growing up in certain cities already show growths, plaques, and tangles linked with Alzheimer’s, Parkinson’s, as well as motor neurone disease (MND).
Whether or not these signs of damage create neurological conditions later in life is still not clear; however, tangles and plaques can gather in the brains of those with Alzheimer’s and other neurological issues. More research is still required to determine what role these markers play and how they engage with disease development.
The Silent Plague
With 90 percent of the globe’s children breathing polluted air, scientists say it is vital to find and analyze more data. If fine particulate matter coming from air pollution causes neurological disease, we need to know now.
“Different people will have different levels of vulnerability to such particulate exposure,” says Lancaster University environmental scientist Barbara Maher, “but our new findings indicate that what air pollutants you are exposed to, what you are inhaling and swallowing, are really significant in the development of neurological damage.”
Earlier this year, researchers warned air pollution was creating a ‘silent plague,’ leading to conditions such as high blood pressure, stroke, diabetes, heart failure, and heart attacks at a rate more deadly than most diseases, war, and violence.
There’s the potential for widespread neurological diseases as well. Evidence from China, the United Kingdom, and the United States shows air pollution levels are relatively associated with cognitive impairment, dementia, and Alzheimer’s.
Although that doesn’t mean air pollution is triggering cognitive damage, other research among Mexico City residents discovered metal nanoparticles from air pollution can enter the brain, providing a path for damage.
Air Pollution and Cognitive Decline
The new research supports that finding. Analyzing the brainstems of 186 young Mexico City individuals who died between 11 months and 40 years of age, scientists found nerve cell growths, plaques, and tangles associated with neurological conditions and small metal-filled nanoparticles.
“The iron-and aluminum-rich nanoparticles found in the brain stem are strikingly similar to those which occur as combustion- and friction-derived particles in air pollution (from engines and braking systems),” says Maher. “The titanium-rich particles in the brain were different – distinctively needle-like in shape; similar particles were observed in the nerve cells of the gut wall, suggesting these particles reach the brain after being swallowed and moving from the gut into the nerve cells which connect the brainstem with the digestive system.”
Even the youngest brain stem that was analyzed, of an 11-months old child, showed nerve cell growths, tangles, and plaques, which form when proteins do not fold properly in the brain.
Because metal-rich particles in the brain can trigger both inflammation and oxidative stress, leading to neurons‘ death, scientists believe air pollution is a tenable cause for cognitive decline.
“It is terrifying because, even in the infants, there is neuropathology in the brain stem,” Maher told The Guardian. “We can’t prove causality so far, but how could you expect these nanoparticles containing those metal species to sit inert and harmless inside critical cells of the brain? That’s the smoking gun – it seriously looks as if those nanoparticles are firing the bullets that are causing the observed neurodegenerative damage.”
A paper detailing the study was published in Environmental Research.