When brain tissue samples were taken from over three dozen people who had lived in the industrial cities of Manchester and Mexico City, researchers found something very peculiar, unlike anything they had studied before. The city dwellers’ brains all had something in common, something that has yet to be fully understood: The frontal cortex of their brains was polluted with magnetite nanoparticles. The brain samples were obtained from people ranging in age from 3 to 92 who had died in fatal accidents; their brains were left intact.
Breathing fine particulate matter causes inflammation in the brain
There was ample evidence that the magnetite nanoparticles were taken in through the polluted air of the city. All signs indicated that the particles had penetrated their blood-brain barriers to congregate in the tissue of the frontal cortex. These newly discovered magnetite nanoparticles were shaped differently from what naturally occurs in the brain. In the brains of Alzheimer’s patients, researchers find higher than normal amounts of magnetite particles, indicating an inflammation factor, but these particles are always angular in shape.
The nanoparticles found in this study were well rounded, indicating that they came from industrial sources. During combustion, these magnetite spheres form after iron is heated and quickly cools. The spheres then release into the air. The brain samples in this study showed both the endogenous angular magnetite particles, ranging in diameter from 50 to 150 nanometers, and also contained the spherical deposits taken in from industrial pollution. These ranged from less than 5 nanometers to more than 100 nanometers in diameter.
Inflammatory magnetite nanoparticles bypass the blood-brain barrier
The researchers hypothesize that the spheres are inhaled and enter the brain through the olfactory bulb. The researchers suspect that the particles are finding a way through the blood-brain barrier by using this neuronal gateway. Once inside the brain these particles can spur free radical damage. When this happens, oxygen is taken from the respiration pathways of the cells, oxidizing them. In theory, cities with all their industrial processes are suffocating us from the inside out. This may be the reason why getting out of the city and breathing the country air is so freeing and relieving: The brain is no longer taking in the particles that cause inflammation, aging and oxidative stress.
The research, which sheds light on the widespread dangers of industrial pollution, was published in the journal, Proceedings of the National Academies of Science. Speaking with The Scientist in an email, Jon Dobson of the University of Florida (not involved with the study) says, “This is the first report of iron oxide particles in brain tissue that may have come from an industrial source. As such, this opens up questions about potential neurotoxic effects from industrial pollutants that had not been previously considered.”
If magnetite particles in the brain indicate inflammation in the brains of Alzheimer’s patients, how might city life and all its industrial pollution be slowly destroying our brains?
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