The increasing prevalence of psychiatric disorders has become a global issue affecting millions of people worldwide each year.
Psychological research has advanced alongside this, meaning several contributing biological factors of particular psychiatric disorders have been identified. However, genetic studies have failed to account for phenotypic variation fully, causing some to argue that the prevalence of disorders is linked to neurochemical, genetic, and environmental factors such as pollution.
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What is Mental Health?
Mental health, defined by the World Health Organization, is “a state of well-being in which the individuals realize his or her abilities, can cope with the normal stresses of life, can work productively and fruitfully, and can make contributions to his or her community.”
The World Health Organization also places particular emphasis on the fact that mental health should not be viewed simply as an individual being free from psychiatric disorders.
Pollution and Mental Health
A growing body of literature has discussed the potential link between environmental pollution and an increased risk of developing psychological disorders.
Researchers from the United States and Denmark investigated the impact of pollution exposure and the prevalence of psychiatric disorders. Observational studies were used in both the US and Denmark and involved the analysis of environmental factors such as air pollution and the treatment of psychiatric disorders.
Specifically, they gathered insurance information from 2003 to 2013 for 151 million people in the US and 1.4 million in Denmark to calculate the number of people in each region who had been diagnosed with schizophrenia, bipolar, personality disorder, Parkinson’s disease, major depression, and epilepsy.
Information regarding the climate, average salary, the ethnic background of residents, population density, and other socioeconomic factors were analyzed to establish whether any of the factors were linked to an increased or decreased prevalence of each psychiatric disorder.
They found that those in Denmark who lived in highly polluted regions during the first ten years of life were at a greater risk of developing schizophrenia, depression, bipolar, and personality disorders. In the US, highly air polluted areas were associated with a higher prevalence of depression and bipolar compared to less polluted areas.
It is important to note that despite the association observed between mental health disorders and air pollution, direct causation is not yet established. Due to the nature of the study, there may be a variety of other influential contributing factors that were unaccounted for.
Furthermore, the researchers had to draw assumptions about residents’ environmental exposure based on their postal address. Therefore, the researchers were unable to note definitive environmental toxins and other influential factors.
Complementary research has found links between air population and the severity of mental health issues in children.
Researchers from the division of Biostatistics and Epidemiology at the Cincinnati Children’s Hospital Medical Center conducted research investigating the effects of short-term exposure to air pollution on the severity of pediatric psychiatric disorders.
They found that short-term exposure of PM2.5 was linked to exacerbations in the children’s psychiatric disorders in one to two days following the exposure. This was marked by an increase of visitation to the Children’s emergency department due to concerns about their psychiatric disorder.
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Additional notable findings include that children who reside in disadvantaged areas were considered to be at greater risk of being susceptible to the effects of air population compared to children residing in well-off neighborhoods. This was particularly relevant to anxiety disorders and suicide.
Research by the same department identified a potential link between pollution and anxiety. Specifically, the researchers found that recent exposure to traffic-related air population (TRAP) was associated with increased generalized anxiety.
The research involved analyzing MRI imaging of children specifically looking at their prevalence of Myo-inositol, a metabolite found in glial cells. Following exposure to high levels of TRAP, the researchers noted a significant increase in Myo-inositol. High levels of the metabolite were also linked to increases in generalized anxiety symptoms.
- World Health Organization (2004). Promoting mental health: Concepts, emerging evidence, practice: summary report. https://apps.who.int/iris/bitstream/handle/10665/42940/9241591595.pdf
- Khan, A., et al. (2019). Environmental pollution is associated with increased risk of psychiatric disorders in the US and Denmark. PLOS. doi: https://doi.org/10.1371/journal.pbio.3000353
- Brokamp, C., et al. (2019). Pediatric psychiatric emergency department utilization and fine particulate matter: A case-crossover study. Environmental Health Perspectives. doi: https://doi.org/10.1289/EHP4815
- Brunst, K. J. (2019). Myo-inositol mediates the effect of traffic-related air pollution on generalized anxiety symptoms at age 12 years. Environmental research. doi: https://doi.org/10.1016/j.envres.2019.05.009
- Sancar F. Childhood Lead Exposure May Affect Personality, Mental Health in Adulthood. JAMA. 2019;321(15):1445–1446. doi:10.1001/jama.2019.1116
- Reuben A, Schaefer JD, Moffitt TE, et al. Association of Childhood Lead Exposure With Adult Personality Traits and Lifelong Mental Health. JAMA Psychiatry. 2019;76(4):418–425. doi:10.1001/jamapsychiatry.2018.4192