Exclusive: if discovery is confirmed it will have global implications as 90% of people breathe dirty air
Tiny air pollution particles have been revealed in the brain stems of young people and are intimately associated with molecular damage linked to Alzheimer’s and Parkinson’s disease.
If the groundbreaking discovery is confirmed by future research, it would have worldwide implications because 90% of the global population live with unsafe air. Medical experts are cautious about the findings and said that while the nanoparticles are a likely cause of the damage, whether this leads to disease later in life remains to be seen.
There is already good statistical evidence that higher exposure to air pollution increases rates of neurodegenerative diseases, but the significance of the new study is that it shows a possible physical mechanism by which the damage is done.
The researchers found abundant pollution nanoparticles in the brainstems of 186 young people from Mexico City who had died suddenly between the ages of 11 months and 27 years. They are likely to have reached the brain after being inhaled into the bloodstream, or via the nose or gut.
The nanoparticles were closely associated with abnormal proteins that are hallmarks of Alzheimer’s, Parkinson’s and motor neurone disease. The aberrant proteins were not seen in the brains of age-matched people from less polluted areas, they said.
“It is terrifying because, even in the infants, there is neuropathology in the brain stem,” said Prof Barbara Maher, at Lancaster University, UK, and part of the research team. “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.”
Maher said the work provides hypotheses that could now be tested. For example, brain stem damage would affect the movement control and gait of young people and this should correlate with pollution exposure if the nanoparticles are the cause.
