Research Shows Air Pollution Affects Our Brains in No Good Very Bad Ways
Multiple studies link air pollution with neurological and mental health issues, even in wealthy nations like the United States
Hiya!
The first time I remember seeing abundant air pollution firsthand was in 2007 on a Chinese freeway while on vacation with my family. I was nineteen at the time and looking out the backseat window of a van, though I can’t recall which city we were in or where we were going. But I do remember the buildings being mere silhouettes amidst the dense fog of pollution. The sheer density surprised me so much that I took a photo:
It’s easy to feel removed from the problems of air pollution when your sky doesn’t look like that image. But the truth is air pollution is a growing crisis with serious health risks already affecting hundreds of millions of people, including in wealthy countries like the United States.
Considering the increasing amount of headlines and research being published on the topic, it seems time to stop ignoring the issue. Even if there’s not much we can do as individuals to fix it, we should still be aware of the situation for when we can do something. Or if nothing else, to better protect ourselves and our loved ones the best we can.
Growing Problem of Air Pollution
I know that you know air pollution is a major problem. How can you not? It’s in the news daily, though mostly related to global warming. Less discussed are the health risks of living with air pollution every day, which is a challenge even in wealthy nations such as the United States.
According to research by the American Lung Association, in 2023, “nearly 36% of Americans — 119.6 million people — live in unhealthy levels of ozone or particle pollution.” That means more than 1 in 3 Americans breathe unsafe air daily. Further, their research also reveals that in the United States, “People of color are 3.7 times more likely than white people to live in a county with three failing grades.”
Though, of course, air pollution is a global problem. Over the last decade, extensive research has clearly established links between air pollution and adverse effects on physical health, including inflammation, asthma, cardiac arrhythmias, and heart disease.
However, until the last few years, it’s been a bit of a struggle for experts to understand the effects of air pollution on our brains. Thankfully recent research discovered links between not just air pollution and our brains but our mental health and behavior too.
Air Pollution’s Effects on the Brain
Studies show there are at least two ways pollutants, even the ultra-fine particles of vehicle exhaust, can enter our brains. One way is by traveling directly in via our nostrils. The other is by being stealthy and creating inflammation which triggers our immune responses and helps them cross the blood-brain barrier. So what happens to the brain when it’s exposed to air pollution? Well, a 2018 study sought to find out.
The journal Environmental Research published the study by toxicologist and neuropathologist Lilian Calderón-Garcidueñas and her colleagues after they examined the brains of over 200 deceased Mexico City residents who died between 11 months and 40 years old. The team also had nine control brains belonging to people who lived and died breathing clean air.
The results? The team described the control brains as “unremarkable,” but found that 199 of the 200 brains from Mexico City residents resembled the brains of people with Alzheimer’s disease.
As terrifying as those results are, some experts say there’s no reason to panic just yet. Mainly because the link between air pollution and Alzheimer’s isn’t definitive, and the study was “limited by methodological issues.”
But Caleb Finch, a biomedical gerontologist at the University of Southern California in Los Angeles, warns that while we may not have to panic, we should pay attention.
“Population-based studies have come into complete agreement on three continents — North America, Western Europe, and Asia — that air pollution above a certain level predicts a higher risk of dementia, particularly Alzheimer’s, and cognitive decline. That’s now proven by at least 10 major studies.”
Well, that sucks.
But wait a minute, if air pollution increases the risks of developing neurological diseases and cognitive decline in the long term, what sort of effects does it have on our daily mental health? Thankfully, a postdoctoral research fellow in Psychiatry and Behavioral Neurosciences and Wayne State University, Clara G. Zundel, had the same curiosity.
Air Pollution’s Effects on Our Mental Health
Zundel aimed to gain deeper insight into the impact of outdoor air pollution on mental well-being and the brain areas responsible for regulating emotions — specifically, the hippocampus, amygdala, and prefrontal cortex. Zundel and her interdisciplinary team of colleagues analyzed over 100 research articles from both human and animal studies focusing on the effects of outdoor air pollution.
They published their research in the journal NeuroToxicology, and Zundel penned an article about their findings in the Conversation. In the article, she writes:
“People who breathe polluted air experience changes within the brain regions that control emotions, and as a result, they may be more likely to develop anxiety and depression than those who breathe cleaner air.”
The researchers found that 73 percent of the studies reported higher rates of negative mental health behaviors and symptoms in both humans and animals, including those in air pollution ranges presently considered “safe” by Environmental Protection Agency standards.
And a whopping 95 percent of the studies looking at brain effects discovered significant function and physical changes in the areas responsible for emotional regulation in the brains exposed to higher levels of air pollution.
Zundel explains that most of the studies found convincing relationships between exposure to high levels of air pollution and increased inflammation and changes to neurotransmitter regulation—which help neurons communicate.
Expensive Costs and Early Deaths
Not only is air pollution clearly bad for our health, but it’s killing us. Also, it’s expensive. In the United States alone, oil and natural gas production contribute to thousands of early deaths and roughly $77 billion in health costs every year.
A recently published study in the journal Environmental Research: Health found that in 2016 alone, fine particulate matter, nitrogen oxide, and ozone from U.S. oil and gas production contributed to about 410,000 asthma attacks, 2,200 new cases of childhood asthma, and 7,500 excess deaths in the United States.
Reports also show that Texas, Pennsylvania, Ohio, Oklahoma, and Louisiana have the highest ratios of “associated health damages.” But of course, air pollution doesn’t care about or stop at borders, which means it’s everyone’s problem.
Perspective Shift
While air pollution is a significant issue, it’s challenging to gauge individual dangers because many people move a lot throughout their lifetime. Perhaps living in 12 homes in different cities, states, or even countries, and each place likely has different exposure levels to air pollution.
But we shouldn’t wait until the effects of air pollution impact us personally. Research shows links between air pollution and health risks, including everything we discussed today, and shouldn’t that be enough? Thankfully the EPA, while not perfect, is working to establish nationwide limits on air pollution from oil and gas development.
As promising as it is, it’ll be a significant challenge from a societal and economic perspective. The good news is we’re an intelligent and creative species capable of achieving anything we set our minds to. Besides, one effect of the pandemic lockdown showed the world that decreasing pollution can have dramatic overnight results.
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Makes perfect sense. And I have the same question that Alex posed about the possibility of recovery when relocating to a less toxic area. I doubt, tho, that that’s been studied.
Very depressing news. Are there any studies that compare people who had only childhood exposure with people who had longer term exposure? For example, do the former recover any brain function in adulthood or become less anxious/depressed if they move to cleaner-air locations post-childhood?