Air pollution harms the brain and mental health too – a large-scale analysis documents the effects on areas of the brain associated with emotions

by Clara G. Zundel, Wayne State University [This article first appeared in The Conversation, republished with permission]

Research briefs are short excerpts of interesting academic work.

The big idea

People who breathe polluted air experience changes within the areas of the brain that control emotions, and as a result, they may be more likely to develop anxiety and depression than those who breathe cleaner air. These are the main findings of a systematic review that my colleagues and I recently published in the journal NeuroToxicology.

Our multidisciplinary team reviewed more than 100 research articles from animal and human studies that focused on the effects of outdoor air pollution on mental health and the areas of the brain that regulate emotions. The three main brain regions we focused on were the hippocampus, amygdala, and prefrontal cortex.

In our analysis, 73% of the studies reported higher mental health symptoms and behaviors in humans and animals, such as mice, that were exposed to above-average levels of air pollution. Some exposures that resulted in adverse effects occurred in air pollution ranges that are currently considered “safe” by EPA standards. In addition, we discovered that 95% of studies examining brain effects found significant physical and functional changes in brain regions that regulate emotions in those exposed to increased levels of air pollution.

Most of these studies found that exposure to elevated levels of air pollution is associated with increased inflammation and changes in the regulation of neurotransmitters, which act as chemical messengers to the brain.

why does it matter

Research on the physical health effects associated with exposure to air pollution, such as asthma and respiratory problems, has been well documented for decades.

But it’s only within the past 10 years or so that researchers have begun to understand how air pollution can affect the brain. Studies have shown that small air pollutants, such as ultrafine particles from vehicle exhaust, can affect the brain either directly, by traveling through the nose to the brain, or indirectly, by causing inflammation and altering immune responses in the body that can cross after that. in the brain.

At the same time, researchers are increasingly documenting the relationship between air pollution and its negative effects on mental health.

Unfortunately, research indicates that air pollution will only get worse as climate change intensifies and carbon emissions appear unregulated.

For this reason, more research on the health effects of air pollution exposure that goes beyond respiratory health outcomes into the field of biological psychiatry is urgently needed. For example, the neurobiological mechanisms through which air pollution increases the risk of developing mental health symptoms are still not well understood.

What is still unknown

In addition to our initial findings, our team also identified some notable gaps in the research that need to be addressed in order to paint a fuller picture of the relationship between air pollution and brain health.

Relatively few studies have examined the effects of exposure to air pollution during early life, such as infancy and infancy, and in childhood and adolescence. This is particularly worrying given that the brain continues to develop into adulthood and may therefore be particularly vulnerable to the effects of air pollution.

We also found that of the studies looking at the effects of air pollution on the brain, only 10 were conducted in humans. While large-scale animal research has shown that air pollution can cause a range of changes within an animal’s brain, research on how air pollution affects the human brain is very limited. Furthermore, most current brain studies have focused on physical changes, such as differences in overall brain size. More research is needed that relies on a technique called functional brain imaging, which can enable researchers like us to detect subtle or smaller changes that may occur before physical changes.

In the future, our team plans to use brain imaging methods to study how air pollution increases the risk of anxiety during adolescence. We plan to use a variety of technologies, including personal air monitors that children can wear as they go about their day, which will allow us to more accurately assess their exposure.

Clara Zundel, Postdoctoral Research Fellow in Psychiatry and Behavioral Neurosciences, Wayne State University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Leave a Reply

%d bloggers like this: