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Toxic air pollution particles found in human brains
Detection of “abundant” magnetite particles raises concerns because of suggested links to Alzheimer’s disease
Toxic nanoparticles from air pollution have been discovered in human brains in "abundant" quantities, a newly published study reveals.
The detection of the particles, in brain tissue from 37 people, raises concerns because recent research has suggested links between these magnetite particles and Alzheimer‘s disease, while air pollution has been shown to significantly increase the risk of the disease. However, the new work is still a long way from proving that the air pollution particles cause or exacerbate Alzheimer‘s.
"This is a discovery finding, and now what should start is a whole new examination of this as a potentially very important environmental risk factor for Alzheimer‘s disease", said Prof Barbara Maher, at Lancaster University, who led the new research. "Now there is a reason to go on and do the epidemiology and the toxicity testing, because these particles are so prolific and people are exposed to them" (…)
The new work, published in the Proceedings of the National Academy of Sciences, examined brain tissue from 37 people in Manchester, in the UK, and Mexico, aged between three and 92.
It found abundant particles of magnetite, an iron oxide. "You are talking about millions of magnetite particles per gram of freeze-dried brain tissue – it is extraordinary", said Maher.
"Magnetite in the brain is not something you want to have because it is particularly toxic there", she said, explaining that the substance can create reactive oxygen species called free radicals. "Oxidative cell damage is one of the hallmark features of Alzheimer‘s disease, and this is why the presence of magnetite is so potentially significant, because it is so bioreactive".
Abnormal accumulation of brain metals is a key feature of Alzheimer‘s disease and a recent study showed that magnetite was directly associated with the damage seen in Alzheimer‘s brains. Magnetite particles are known to form biologically in human brains, but these are small and crystal-shaped, unlike the larger, spherical particles that dominated the samples in the new study.
"Many of the magnetite particles we have found in the brain are very distinctive", said Maher. "They are very rounded nanospheres, because they were formed as molten droplets of material from combustion sources, such as car exhausts, industrial processes and power stations, anywhere you are burning fuel".
Available at: <https://www.theguardian.com/environment/2016/sep/05/toxicair- pollution-particles-found-in-human-brains-links-alzheimers>.
Accessed on: 06 Sept. 2016.
Glossary
hallmark: marca, característica própria; droplets: gotículas.
According to the seventh paragraph of Text, the magnetite particles most commonly found in the new study are distinct from the kind of particles found earlier because they
