by 
CNN
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According to a new study, people who live in a heavily polluted area have a much higher risk of depression and anxiety than those who live with clean air.
The study, published Wednesday in the journal JAMA Psychiatry, found that people who were exposed to higher levels of several air pollutants — including particulate pollution, nitrogen dioxide and nitric oxides — over a long period of time had an increased risk of depression and anxiety.
Particulate pollution, also known as particulate matter, is the mix of solid and liquid droplets suspended in the air, says the US Environmental Protection Agency. It can come in the form of dirt, dust, soot or smoke. Coal and natural gas power plants generate it, as do cars, agriculture, dirt roads, construction sites and forest fires.
Nitrogen dioxide pollution is most commonly associated with traffic-related combustion by-products. Nitrogen oxides are also released by traffic and the burning of oil, coal and natural gas.
The smallest particulate matter found in the new study, PM2.5, is so tiny — 1/20 the width of a human hair — that it can get past your body’s usual defenses.
Instead of being performed on the exhale, it can get stuck in your lungs or enter your bloodstream. The particles cause irritation and inflammation and can lead to breathing problems. exposure can cause cancer, stroke, or heart attack; It could also make asthma worse and has long been linked to a higher risk of depression and anxiety.
For the new study, the researchers examined the records of 389,185 people from the UK Biobank, a large-scale biomedical database of half a million different volunteers. During the study period, 13,131 were diagnosed with depression and 15,835 with anxiety disorder.
The higher the level of pollution in the area the person lived, the higher the risk of depression and anxiety, even when pollution levels were below UK air quality standards, the researchers found.
The risk of anxiety associated with exposure to PM2.5 was greater in men than in women.
The study can’t pinpoint the reason for the general connection, but others have found that exposure to air pollution can affect the central nervous system, causing inflammation and damaging the body’s cells.
According to studies, some air pollution can also cause the body to release pollutants that can harm people blood-brain barrier, the network of blood vessels and tissues made up of closely spaced cells that protect the brain, and that can lead to anxiety and depression. However, more research is needed to fully understand this association, as the neural basis for both anxiety and depression is not fully understood.
Other studies have found that pollution can affect the onset of anxiety and depression, said Dr. Marianthi-Anna Kioumurtzoglou, Associate Professor of Environmental Health Sciences at the Mailman School of Public Health in Colombia. She wasn’t involved in the new research but did similar work on the link between air pollution and depression.
“There are several studies showing that air pollution is also associated with aggravation. For example, if there is air pollution today and yesterday, we see an increase in our hospitalizations for these diseases,” Kioumurtzoglou said.
you and your colleagues have also found links to other neurodegenerative diseases such as Alzheimer’s and Parkinson’s.
“The link between air pollution and the brain is now fairly consistent in the literature,” said Kioumurtzoglou.
Limitations of the new research include a lack of information on other common air pollutants such as ozone, carbon monoxide or sulfur dioxide.
“Not all air pollutants are created equal. Some are more toxic than others. And for certain diseases, there is still a lot to be done,” said Kioumurtzoglou.
The authors of the study hope the research findings will encourage policymakers to do whatever they can to reduce exposure to pollution.
“Given that many countries’ air quality standards are still well above the World Health Organization’s latest 2021 global air quality guidelines, more stringent clean air standards or regulations should be introduced into future policymaking,” the authors write.
