The Adverse Effects of Air Pollution on Mental Well-Being

Air pollution is the term used to describe any chemical, physical, or biological factor that tampers with the natural properties of the atmosphere to contaminate the indoor or outdoor environment. Common causes of air pollution include motor vehicles, industrial operations, household combustion appliances, and forest fires. Particulate matter, ozone, nitrogen dioxide, sulfur dioxide, and carbon monoxide are among the pollutants that pose a serious threat to public health. Air pollution, both indoors and outdoors, is a major cause of morbidity and mortality and causes diseases such as respiratory disorders.

According to WHO data, nearly all people on Earth (99%) breathe air that is more polluted than what is recommended and exceeds WHO guideline limits; the biggest exposures occur in low- and middle-income nations.

What effects might air pollution have on mental health?

Studies on the neurological impacts of air pollution have shown that exposure to PM causes an increase in brain inflammation. Anxiety and depression are associated with elevated levels of cytokines, which are chemicals that control the inflammatory response in the body. Numerous disorders of the central nervous system, including Parkinson’s and Alzheimer’s diseases, are also associated with long-term neuroinflammation.

Air pollution and Mental Health

There is growing evidence that exposure to air pollution, both indoors and outdoors, can have negative impacts on respiratory and cardiovascular health in addition to potentially causing neurocognitive disorders and having direct or indirect effects on mental health through a variety of possible causal pathways. There is a link between ill health and poor air quality. The wide range of environmental exposures and air contaminants that have an impact on mental health throughout life are rarely discussed.

Also Read: New Study Links Air Pollution to Mental Health Issues!

Previous studies have linked air pollution to elevated stress levels, psychological distress, a higher chance of dementia and Alzheimer’s disease, and depression. Additional studies have connected persons, with severe mental illnesses to a higher death risk when they are exposed to short-term highs in air pollution.

Scientists believe that inflammation is the main mechanism by which air pollution impacts mental health, even if research in this area is still in its infancy. It is well-recognized that exposure to air pollution triggers inflammatory reactions in the body and that persistent inflammation in the brain can harm neurons and the regulatory responses of the nervous system.

According to studies on animals…

There are several ways that air pollution might enter the brain and trigger this inflammation. By getting beyond the blood-brain barrier, which serves as a barrier between the blood vessels in the brain and the cells that comprise brain tissue and act as an immune system against poisons and infections found in our blood.

When contaminated air is breathed into the nose, it can harm the neurons, thereby penetrating the olfactory neurons that connect the nose to the brain. Getting into the stomach and digestive tract, are home to the enteric nerve system, popularly known as the “second brain,” which regulates our emotions and general health. According to studies, persistent inflammation in animals can resemble human bipolar illness and depression symptoms.

Air Pollution and Cognition Problems

Anxiety, sadness, and neurodegenerative illnesses are just a few of the major physical and mental health issues in adults that have been connected to air pollution. Fine particulate matter is one of the pollutants that has been the subject of the majority of studies on air pollution. These minuscule particles, which are 1/30th the width of a human hair, are released by factories, autos, power plants, and trucks. Particulate matter is one of the six main pollutants for which the Environmental Protection Agency (EPA) has set air quality regulations because of its well-documented impact on cardiovascular health.

It now appears possible that particulate matter’s detrimental effects extend beyond vascular injury. Rush Medical College assistant professor of internal medicine Jennifer Weuve, MPH, ScD, discovered that older women exposed to high concentrations of the pollutant had more cognitive impairment than other women of the same age (Archives of Internal Medicine, 2012). The Nurses’ Health Study Cognitive Cohort, which comprised almost 19,000 women in the United States between the ages of 70 and 81, provided the data that Weuve’s team used. Weuve and her colleagues calculated the women’s exposure to particulate matter over the past seven to fourteen years based on their address history. According to tests of cognitive ability, the women’s long-term exposure to high pollution levels considerably accelerated their cognitive loss.

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Air Pollution and Depression

Vert et al. (19) from Barcelona found that individuals exposed to various air pollutants had considerably higher rates of depression. The risks of depression were found to double for every 10 μg/m3 rise in NO2 in the community. Additionally, correlations between increased air pollution concentrations and the use of psychiatric medications were found in this investigation. In a similar vein, Lim and associates showed that elderly residents of Seoul, Republic of Korea, had a markedly higher chance of experiencing depressed symptoms, particularly emotional symptoms. Similar, albeit more cautious increases were seen in a US study: 1.06 and 1.08 hazard ratios of depression at 10 μg/m3 increases in PM2.5 and 0.3, respectively.

Furthermore, studies evaluating emergency department visits for depressive episodes showed a strong correlation between worse 3-day rolling average air quality measures and individuals with pre-existing mental disorders and physical co-morbidities. When similar outcomes were assessed daily, emergency department attendance for depressive episodes was significantly higher for specific combinations of air pollutants at specific times.

For instance, in Edmonton, Canada, female patients’ emergency department attendance increased by 7.4% (95% CI: 0.5, 14.8) during periods when NO2 was especially high during warm seasons.

Air Pollution and Psychosis

The literature has long shown variations in the incidence of schizophrenia in urban and rural areas, and more recently, air pollution has been implicated as a possible mediator of this relationship. As of right now, the data Is weak, and an examination of the relationship can only suggest that exposure to environmental heavy metals—particularly lead and cadmium—may have a causal effect on the neurological pathways that contribute to the development of schizophrenia.

Air Pollution and Anxiety

Estimates of air pollution exposure and the distance to the closest major road were published in Power and colleagues’ observational cohort study, which used the US nurses’ cohort. The researchers discovered that nurses who had been exposed to greater levels of PM10 and PM2.5 particulate matter in the month and year prior had much-increased probabilities of experiencing “meaningfully high symptoms of anxiety.” Compared to the previous year, nurses who were exposed to an average increase of 10 mcg/m3 in PM2.5 had 1.15 (1.06 to 1.26) higher odds of experiencing significant anxiety symptoms. Similarly, after controlling for a variety of socioeconomic factors, associations between particulate matter concentration and anxiety symptoms have been documented.

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Additionally, this study discovered that people with pre-existing physical health disorders and those from lower socioeconomic categories had a stronger correlation between anxiety symptoms and air pollution.

In 2019, a study conducted on individuals in Denmark and the United States discovered that those who were exposed to more polluted air had greater incidences of mental illnesses such as bipolar disorder, schizophrenia, depression, and personality disorders. According to the study, exposure to high levels of air pollution has been linked to an increase in bipolar disorder by 31%, schizophrenia by 104%, personality disorder by 210%, and major depression by 68%.