Air pollution in highly industrialized urban areas has been implicated in diseases like cancer and respiratory illnesses and it damages the environment as well, affecting crops and animals, but in a first of its kind study, researchers have found nanoparticles of magnetite, an iron oxide compound, in human brain tissue.
It’s not the first time magnetite has been detected in the brain. About 25 years ago researchers at Cal Tech discovered biologically formed bits of the compound in the brain. They theorized at the time that it might be the result of iron in the bloodstream. The most recent findings though are not biological in origin, but instead can be traced to industrial pollution.
A team of researchers from Lancaster University in England studied brain tissue of 37 individuals. They ranged in age from 3 to 92 years old. The tissue was taken post mortem from the frontal cortex of the brain. Most of those examined lived in Mexico City, however there were some samples from people in the area of Manchester England as well. The particles found in the study were spherical in shape and this was a key finding. Particles that form biologically have a geometric shape, either tetrahedral or octahedral.
Physicist Barbara Maher is co-director of the Centre for Environmental Magnetism and Paleomagnetism at Lancaster University and led the team. She is an expert in particles found in the environment as a result of industrial pollution. Hi-res imaging and electron spectrometry was used to get a look at the brain tissue and the particles found in the brain tissue were almost identical to those that are contained in the smoke that is emitted by power plants.
In addition, some of them contained traces of other metals like platinum, cobalt and nickel which do not naturally occur in the body, but are in the air surrounding power plants. In an interview with the journal Science she stated, “They showed all the properties suggesting they formed in high temperatures. Those temperatures vary with the fuel being burned, but they are much higher than those of the human body. “[The nanospheres are] combustion byproducts, like what’s found in power station pollution.”
The particles are highly toxic and the research has sparked new debate about the cause of Alzheimer’s disease. Magnetite causes cell stress, which in turn can create free radicals, molecules which are thought to contribute to the forming and strength of beta amyloid plaques in the brain. These plaques are what disrupt memory in Alzheimer’s. While there is no clear link to the particles and Alzheimer’s, there is previous research that shows some correlation between high levels of magnetite and the incidence of Alzheimer’s.
The particles are small enough that it’s likely they are inhaled through the nose and enter the brain through the olafactory nerves. The fact that they have all the hallmarks of particles formed from the frictional heat and combustion that is seen in air pollution is truly a game changing finding in environmental science as well as research in neuroscience. The video below features Maher and explains more about the study, check it out.
, Lancaster University