[Editor's note: now why would a magnetic particle get lodged in and around neurons?]
Tiny magnetic particles from air pollution have for the first time been discovered to be lodged in human brains– and researchers think they could be a possible cause of Alzheimer’s disease.
Researchers at Lancaster University found abundant magnetite nanoparticles in the brain tissue from 37 individuals aged three to 92-years-old who lived in Mexico City and Manchester. This strongly magnetic mineral is toxic and has been implicated in the production of reactive oxygen species (free radicals) in the human brain, which are associated with neurodegenerative diseases including Alzheimer’s disease.
Professor Barbara Maher, from Lancaster Environment Centre, and colleagues (from Oxford, Glasgow, Manchester and Mexico City) used spectroscopic analysis to identify the particles as magnetite. Unlike angular magnetite particles that are believed to form naturally within the brain, most of the observed particles were spherical, with diameters up to 150 nm, some with fused surfaces, all characteristic of high-temperature formation – such as from vehicle (particularly diesel) engines or open fires.
The spherical particles are often accompanied by nanoparticles containing other metals, such as platinum, nickel, and cobalt.