Dementia and air pollution: Particulate matter in road traffic can be dangerous

Current statistics show that 99% of the world population lives in an area that does not meet the organization’s air quality guidelines, making air pollution one of the top environmental health risks.

Particulate matter – also known as particle pollution – is a type of air pollution consisting of extremely small solid particles mixed with liquid droplets. These solid particles can include dust, dirt, smoke, or soot large enough to be visible, but it’s the very fine particles, less than 2.5 microns, that worries researchers the most. This is because they can penetrate deep into the lungs and into the bloodstream. These tiny particles are about 30 times smaller than a human hair.

Particulate pollution comes from a variety of sources, including:

• transport vehicles
• industrial factories
• Forest fires
• coal burning
• construction sites
• agricultural processes

“Particulate matter is not a homogeneous entity – it consists mainly of inorganic ions, metals and organic substances,” explained Dr. Ehsan Abolhasani, lead author of this study, researcher in the Department of Psychiatry at McGill University and former graduate research assistant in the Department of Epidemiology and Biostatistics at Western University, London, Ontario, Canada.

“It can also carry other viruses and dangerous molecules into the human body,” he said.

Because of its small size, Dr. Abolhasani found that PM2.5 can escape immune cells in the lungs, spread into the bloodstream and cross the brain’s barriers.

“In the brain, it can cause reactions such as inflammation and have toxic effects on cells, leading to this neuron death. In addition, PM2.5 is assigned cardiovascular diseasewhich may also contribute to dementia risk,” he said Medical news today.

A study earlier this year found that air pollution was to blame 9 million premature deaths in 2015.

dr Abolhasani said there are numerous studies showing a link between air pollution and the onset of dementia, but sometimes with conflicting results.

“Therefore, we decided to evaluate all available studies on such an association and to draw a conclusion on the association between the occurrence of dementia and chronic exposure to traffic-related air pollutants, particularly particulate matter,” he said.

For this study, the researchers evaluated data from 17 studies that examined an association between air pollution and the risk of dementia. The participants in all studies were over 40 years old. Of the more than 91 million participants the researchers evaluated in the 17 studies, 5.5 million, or 6% of them, developed dementia.

All studies examining the association between fine air pollution (PM2.5) adjusted for other factors associated with dementia, such as age, gender, smoking and alcohol. Most studies were matched for educational level, weight, and physical activity.

People live in poverty all over the world tend to live in more polluted areas, although this relationship is not as clear in European studies. Most of the studies included in this meta-analysis adjusted for some level of poverty, such as B. Income or eligibility for Medicaid.

The research team also found that the participants who did not develop dementia had lower average daily exposure to particulate matter. In addition, the team found that for every microgram per cubic meter (µg/m3) of particulate matter exposure, a person’s risk of dementia increased by 3%.

“The pooled 3% increase in risk is clinically meaningful since the recommended safe exposure level is approximately 10 to 12 μg/m3,” said Dr. Abolhasani.

“A number of studies in Asia, India and Africa have reported average exposures ranging from 29 to 42 μg/m3. While we cannot determine a precise safe level of exposure to prevent dementia, we should consider ways to reduce traffic-related air pollution in urban areas to reduce the risk of dementia.”
— dr Ehsan Abolhasani

Regarding the next steps in this research, Dr. Janet Martin, a member of the research team, said they planned to further assess global trends in dementia to determine if there is a link between effective measures to reduce air pollution and downward trends in new cases of dementia.

dr Martin is an Associate Professor in the Department of Anesthesia and Perioperative Medicine and the Department of Epidemiology and Biostatistics at the Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada.

“Based on these findings, we intend to advocate for policies that significantly reduce the risk of dementia for our generation and future generations. Without a clear action plan, dementia will only become a bigger problem,” she said MNT.

“If environmental exposure to higher concentrations of particulate matter is a risk factor for dementia, it provides a discrete, actionable focus for efforts at the national and global levels to find ways to reduce PM2.5 to safer levels while allowing for healthy growth.” support and innovation in all countries.”
– dr Janet Martin

“Given this knowledge, we now need to investigate what measures work best to keep PM2.5 levels below safe thresholds while supporting healthy urban societies with many opportunities for growth and innovation,” added Dr. Martin added.

Medical news today also spoke to dr. Scott Kaiser, a geriatrician and director of Geriatric Cognitive Health at the Pacific Neuroscience Institute at Providence Saint John’s Health Center in Santa Monica, California, about this research.

He said there are many ways air pollution can increase the risk of dementia, including inflammation of the brain and nervous system, oxidative stress and harmful effects on the lungs and heart.

“And among all of this, we know that air pollution increases the risk of heart disease and stroke, as well as vascular damage in the brain. And we know that the underlying vascular pathology, along with neurodegeneration, also increases the risk of dementia,” he continued.

Because air pollution is a modifiable risk for dementia, Dr. Kaiser that there are some protective measures that people can take. For example, he suggested not exercising in high-traffic areas or where air quality is poor.

“There are airboards that give air quality ratings and even in your weather app (on your phone) [where] You can see information about particulate matter and air quality,” he explained.

“[Be]particularly careful when particulate matter is high in the air and when air quality is poor, to heed these warnings and not exercise outdoors if it is unsafe.” [to] Outdoor exercise… could go a long way.”
– dr Scott Kaiser

dr Kaiser said this study points to what we can do together to create cleaner air and work towards it.

“Much more needs to be done to understand the ways in which air pollution increases this risk, but also what we can do about it, what we need to do to create brain-healthier environments. And it’s exciting to think of a whole generation of work that can shed light on that path forward,” he said.