ِAt least that is clear from the evidence presented in a study in brain tissue samples.

Researchers at the University of Lancaster, England, found that small metal particles that flow from the exhaust gases of combustion can be introduced through the nose and travel to the brain human.

Once there, the scientists suggest, they can cause brain damage and contribute, for example, disease of Alzheimer .

The finding, the researchers say, presents a new series of questions about the risks of pollution on health.

“Shocking”

Several studies in the past have focused on the impact of polluted air in the lungs and heart.

But this is the first time a research focuses on the effect on the brain .

ara the study, published in Proceedings of the National Academy of Science (PNAS), the scientists analyzed samples of brain tissue from 37 people: 29 of them, aged between 3 and 85 years, had lived and died in Mexico City, one notoriously polluted area.

The other eight people had lived in Manchester, England, they were between 62 and 92 years, and some had died of neurodegenerative diseases of varying degrees of severity.

It was already known that iron nanoparticles may be present in the brain , but usually it is assumed that they come from the mineral found naturally in our body and is derived from food.

But what researchers are now found particles of other mineral magnetite.

Professor Barbara Maher, lead author of the study, had already identified magnetite particles in air samples collected near a busy street in Lancaster and in front of a power plant.

I suspect that these same particles could be found in the samples cerbero. And that was discovered.

“It was very shocking,” he told the BBC science.

“When we study the tissue we saw the particles distributed between the cells and when we did an extraction of magnetite particles were millions, millions in a single gram of brain tissue.”

“Those are millions of opportunities to cause damage,” he says.

origins

To verify that the nanoparticles came from the exhaust gases of combustion, researchers analyzed the shape of the magnetite.

This mineral may also be present in the brain naturally, but in small amounts, and has a toothed shape distinctively.

Nanoparticles were found in the study, however, were not only more numerous, but also smooth and round.

According to the researchers, are features that can only be created in the high temperatures of a vehicle or engine brake systems.

“They are spherical shapes and have small crystallites around its surface, appear along with other metals, such as platinum, arising from catalytic converters,” says Professor Maher.

“It ‘s the first time we see these particles of pollution within the human brain. It is a finding that raises a whole new area of research to understand whether these magnetite particles are causing or accelerating neurodegenerative diseases , ” he adds.

The study did not show conclusive results in this regard.

The brains of Manchester donors, especially those who had died of neurodegenerative disorders, had elevated levels of magnetite.

In victims of Mexico City similar or higher levels are found.

The highest level was discovered magnetite in a Mexican man of 32 years who died in an accident of traffic .

¿Risk of Alzheimer ?

Large particles Scrapping pollution such as soot can be trapped inside the nose. Other smaller can enter the lungs, and the smallest can reach the bloodstream.

But it is thought that the magnetite nanoparticles are so tiny that they can pass from the nose and the olfactory bulb to the nervous system and to the frontal cortex of the brain.

Some experts believe that this could be a “significant risk” of developing neurodegenerative diseases such as Alzheimer’s , but for now, underline, has not been proven that there is a link.

“This study provides compelling evidence that the magnetite from environmental pollution can enter the brain, but does not tell us what effect does this have on the health of our brain or disorders such as disease Alzheimer ” says Dr. Clare Walton, Alzheimer’s Society organization.

“The causes of dementia are complex and so far there has not been enough studies to show whether living in cities and in contaminated areas increases the risk of dementia.”

“More research is needed,” said the expert.

Prevention

Professor Barbara Maher who directed the study said their finding Lancaster- has forced to make changes in their lifestyle to avoid, if possible, contamination .

“Because the magnetite is so toxic to the brain, has shown me the air I breathe differently,” she said researcher New Scientist magazine.

“If I walk on a busy street me away everything I can to the edge of the platform.”

“If I walk a sloping street, crossed to the side where the traffic goes down.” The vehicles will rise generated more particulate matter. ”

“If I’m driving, I just never stop behind a car . In traffic heavy the best option is to have an air conditioner in recirculation mode. And always choose my route for transit through the streets alternatives , ” says the researcher.