Inhaling Alzheimer’s Through the Nose
Although the blood-brain barrier prevents pollutants from reaching the brain, if the particles are microscopic enough, they can travel through the olfactory bulb – the brain structure that interprets input from the nose -- after gaining entrance through the nasal passages. Evidence for this was seen in a review of 60 population studies carried out in 2016. The researchers found the link between air pollution and dementia to be "particularly strong." Further verification for its brain effects comes from a study just published in the Proceedings of the National Academy of Sciences (PNAS). The scientists found air pollution causes lower performance at math and damages language skills. Studies that look at populations imply, but can't determine for sure, if pollution enters the brain, but animal research and human imaging studies leave no doubt. The findings about magnetite developed by Professor Maher, from Lancaster University, England, and eight associates from five other universities in four countries, reveal this in a particularly stark way.Found Naturally in the Brain
Their work, also published in PNAS, looked at brain tissue from 37 people aged between three and 92 who had lived in industrial areas of England and Mexico during their lifetimes. Using an extremely high resolution microscope, the scientists found extensive levels of magnetite, formed from iron oxide, in brain slices. The magnetic mineral compound was first discovered in the brain in 1992, where it occurs naturally. In 2008, higher levels were linked for the first time to Alzheimer's disease. Magnetite is very toxic, causing cell damage from the creation of free radicals. A rodent study found amyloid beta, the protein linked to Alzheimer's, was more toxic in combination with magnetite. As they expected, Dr. Maher and her team found the naturally-occurring magnetite with its familiar angular shapes in the brain samples. But that wasn't the concern – this is. . .100 Industrial Particles for Every Natural One
In a research first, they also found a distinctive spherical type of magnetite that is "strikingly similar" to those formed when fuel is burned, such as that from power stations, vehicle engines and open fires, and from frictional heating as in vehicle brakes. They also detected particles of nickel, platinum and cobalt which do not occur naturally in the brain. What shocked the researchers was that for every crystal-shaped endogenous or “natural” particle, there were a hundred pollutant particles. This amounts to millions of magnetite particles for every gram of brain matter. Dr. Maher described magnetite as "a dangerous mineral...pernicious in its effect on the brain." She continued: "...when you actually see the extracted particles and you see hundreds and thousands visible, then that's when it hits home that there's a prolific amount of magnetite in the brain that shouldn't be there." Particle sizes less than 200 nanometers (nm) are able to enter the brain. Yet magnetite ranges from 50 nm to 150 nm in its crystal form and less than five to over 100 spherically. To give some perspective, the width of a human hair is 75,000 nm and a red blood cell is 6,000 - 8,000 nm.Other Experts Concerned
Dr. Clare Walton from the Alzheimer’s Society commented, “This study offers convincing evidence that magnetite from air pollution can get into the brain..." Jon Dobson, PhD, an expert on magnetic micro and nanoparticles at the University of Florida, added, "This is a very intriguing finding and it raises a lot of important questions.” And according to fellow study author Professor David Allsop, a specialist in Alzheimer’s at the University of Lancaster, “This finding opens up a whole new avenue for research into a possible environmental risk factor for a range of different brain diseases.” Joe Kirschvink, the scientist who first detected magnetite in the brain, put forward his view: “Once you start getting larger volumes of [environmental] magnetite, the chemical reactivity goes way up. That nanoparticles of industrially generated magnetite are able to make their way into the brain tissues is disturbing.” There are few options when looking for protection against magnetite. Even the best particulate face masks with a rating of P100 only guarantee to block particles 0.3 microns or larger. That's the equivalent of 300 nanometers. The masks are not fine enough to prevent the magnetite particles getting through. If you're looking for a reason to move out of an urban area and into the countryside, this study provides a good one.