Tiny magnetic particles produced by car engines and brakes can travel into the human brain and may trigger Alzheimer’s disease, scientists have warned.
Air pollution has already been implicated in lung disease and heart attacks and recent studies have suggested that it could also be a factor in cognitive decline with a US study in 2014 showing that people in highly polluted areas were 50% more likely to suffer mental decline.
Researchers at Lancaster, Oxford and Manchester Universities discovered microscopic spheres of the mineral magnetite in the brains of 37 people in Manchester and Mexico who had suffered neurodegenerative disease.
The mineral magnetite is known to be toxic and is linked to the production of free radicals which are associated with Alzheimer’s disease. A form of iron oxide, magnetite is known to be produced in car engines, particularly diesel engines which can emit up to 22 times more particulates than petrol engines, as well as when brakes are used, both by cars and trains. It can also be produced by open fires and poorly-fitted stoves.
Although magnetite has previously been found in the brains of people who had died of Alzheimer’s disease, it was thought it occurred naturally. However new findings suggested they had been formed during extreme heat, such as in a car engine.
Researchers said the findings opened up a ‘whole new avenue’ into the causes of Alzheimer’s disease, while charities said it offered ‘convincing evidence’ that the toxic particles could get into the brain, reports telegraph.co.uký.
“Our results indicate that magnetite nanoparticles in the atmosphere can enter the human brain where they might pose a risk to human health, including conditions such as Alzheimer’s’” said lead author Prof. Barbara Maher, of Lancaster University.
“The particles we found are strikingly similar to magnetite nanospheres that are abundant in the airborne pollution found in urban settings, especially next to busy roads and which are firmed by combustion or frictional heating from vehicle engines or brakes.”
Worldwide, nearly 44 million people have Alzheimer’s or a related dementia, and the figure is expected to increase as the population grows older.
“This is an important study and adds to the body of evidence that the combustion of fossil fuels has widespread toxic effects on our health,” said Prof. Anthony Seaton, professor of Environmental and Occupational Medicine at the UK’s University of Aberdeen.
“The solution is literally in our own hands as we take hold of the steering wheel.”
