Studies link air pollution to mental health issues in children
September 25, 2019
Science Daily/Cincinnati Children's Hospital Medical Center
Three new studies by scientists at Cincinnati Children's Hospital Medical Center, in collaboration with researchers at the University of Cincinnati, highlight the relationship between air pollution and mental health in children.
A study to be published Sept. 25 in Environmental Health Perspectives found that short-term exposure to ambient air pollution was associated with exacerbations of psychiatric disorders in children one to two days later, as marked by increased utilization of the Cincinnati Children's emergency department for psychiatric issues. The study also found that children living in disadvantaged neighborhoods may be more susceptible to the effects of air pollution compared to other children, especially for disorders related to anxiety and suicidality.
The lead authors of this study are Cole Brokamp, PhD, and Patrick Ryan, PhD. They are researchers in the division of Biostatistics and Epidemiology at Cincinnati Children's.
"This study is the first to show an association between daily outdoor air pollution levels and increased symptoms of psychiatric disorders, like anxiety and suicidality, in children," says Dr. Brokamp. "More research is needed to confirm these findings, but it could lead to new prevention strategies for children experiencing symptoms related to a psychiatric disorder. The fact that children living in high poverty neighborhoods experienced greater health effects of air pollution could mean that pollutant and neighborhood stressors can have synergistic effects on psychiatric symptom severity and frequency."
Two other Cincinnati Children's studies were recently published that also link air pollution to children's mental health:
· A study published in Environmental Research found an association between recent high traffic related air pollution (TRAP) exposure and higher generalized anxiety. The study is believed to be the first to use neuroimaging to link TRAP exposure, metabolic disturbances in the brain, and generalized anxiety symptoms among otherwise healthy children. The study found higher myoinositol concentrations in the brain -- a marker of the brain's neuroinflammatory response to TRAP.
· The lead authors of this study are Kelly Brunst, PhD, a researcher in the department of Environmental Health at the University of Cincinnati, and Kim Cecil, PhD, a researcher at Cincinnati Children's.
· A study published in Environmental Research found that exposure to TRAP during early life and across childhood was significantly associated with self-reported depression and anxiety symptoms in 12 year olds. Similar findings have been reported in adults, but research showing clear connections between TRAP exposure and mental health in children has been limited.
The lead authors of the study are Kimberly Yolton, PhD, director of research in the division of General and Community Pediatrics at Cincinnati Children's, and Dr. Ryan.
"Collectively, these studies contribute to the growing body of evidence that exposure to air pollution during early life and childhood may contribute to depression, anxiety, and other mental health problems in adolescence," says Dr. Ryan. "More research is needed to replicate these findings and uncover underlying mechanisms for these associations."
https://www.sciencedaily.com/releases/2019/09/190925075731.htm
Is pollution linked to psychiatric disorders?
August 20, 2019
Science Daily/PLOS
Researchers are increasingly studying the effects of environmental insults on psychiatric and neurological conditions, motivated by emerging evidence from environmental events like the record-breaking smog that choked New Delhi two years ago. The results of a new study publishing August 20 in the open-access journal PLOS Biology by an international group of researchers using large data sets from the US and Denmark suggests a possible link between exposure to environmental pollution and an increase in the prevalence of psychiatric disorders.
The team found that poor air quality was associated with higher rates of bipolar disorder and major depression in both US and Danish populations. The trend appeared even stronger in Denmark, where exposure to polluted air during the first ten years of a person's life also predicted a more than two-fold increase in schizophrenia and personality disorders.
"Our study shows that living in polluted areas, especially early on in life, is predictive of mental disorders in both the United States and Denmark," said computational biologist Atif Khan, the first author of the new study. "The physical environment -- in particular air quality -- warrants more research to better understand how our environment is contributing to neurological and psychiatric disorders."
Although mental illnesses like schizophrenia develop due to a complex interplay of genetic predispositions and life experiences or exposures, genetics alone do not account entirely for variations in mental health and disease. Researchers have long suspected that genetic, neurochemical and environmental factors interact at different levels to affect the onset, severity and progression of these illnesses.
Growing evidence is beginning to provide insight into how components of air pollution can be toxic to the brain: Recent studies on rodents suggest that environmental agents like ambient small particulate matter (fine dust) travel to the brain through the nose and lungs, while animals exposed to pollution have also shown signs of cognitive impairment and depression-like behavioral symptoms. "We hypothesized that pollutants might affect our brains through neuroinflammatory pathways that have also been shown to cause depression-like signs in animal studies," said Andrey Rzhetsky, who led the new study.
To quantify air pollution exposure among individuals in the United States, the University of Chicago team relied on the US Environmental Protection Agency's measurements of 87 air quality measurements. For individuals in Denmark, they used a national pollution register that tracked a smaller number of pollutants with much higher spatial resolution.
The researchers then examined two population data sets, the first being a U.S. health insurance claims database that included 11 years of claims for 151 million individuals. The second dataset consisted of all 1.4 million individuals born in Denmark from 1979 through 2002 who were alive and residing in Denmark at their tenth birthday. Because Danes are assigned unique identification numbers that can link information from various national registries, the researchers were able to estimate exposure to air pollution at the individual level during the first ten years of their life. In the US study, exposure measurements were limited to the county level. "We strived to provide validation of association results in independent large datasets," said Rzhetsky.
The findings have not been without controversy. "This study on psychiatric disorders is counterintuitive and generated considerable resistance from reviewers," said Rzhetsky. Indeed, the divided opinions of the expert reviewers prompted PLOS Biology to commission a special companion article from Prof. John Ioannidis of Stanford University (Ioannidis is unconnected with the study, but assisted the journal with the editorial process).
"A causal association of air pollution with mental diseases is an intriguing possibility. Despite analyses involving large datasets, the available evidence has substantial shortcomings and a long series of potential biases may invalidate the observed associations," says Ioannidis in his commentary. "More analyses by multiple investigators, including contrarians, are necessary."
Rzhetsky also cautioned that the significant associations between air pollution and psychiatric disorders discovered in the study do not necessarily mean causation, and said that further research is needed to assess whether any neuroinflammatory impacts of air pollution share common pathways with other stress-induced conditions.
https://www.sciencedaily.com/releases/2019/08/190820141604.htm
Air pollution linked to childhood anxiety
Researchers investigate traffic-related air pollution and symptoms of childhood anxiety, through neuroimaging
May 21, 2019
Science Daily/University of Cincinnati Academic Health Center
A new study looks at the correlation between exposure to traffic-related air pollution (TRAP) and childhood anxiety, by looking at the altered neurochemistry in pre-adolescents.
Exposure to air pollution is a well-established global health problem associated with complications for people with asthma and respiratory disease, as well as heart conditions and an increased risk of stroke, and according to the World Health Organization, is responsible for millions of deaths annually. Emerging evidence now suggests that air pollution may also impact the metabolic and neurological development of children.
A new study from researchers at the University of Cincinnati and Cincinnati Children's Hospital Medical Center looks at the correlation between exposure to traffic-related air pollution (TRAP) and childhood anxiety, by looking at the altered neurochemistry in pre-adolescents.
"Recent evidence suggests the central nervous system is particularly vulnerable to air pollution, suggesting a role in the etiology of mental disorders, like anxiety or depression," says Kelly Brunst, PhD, assistant professor in the Department of Environmental Health at the College of Medicine, and lead author on the study.
"This is the first study to use neuroimaging to evaluate TRAP exposure, metabolite dysregulation in the brain and generalized anxiety symptoms among otherwise healthy children," says Brunst.
The study was published by the journal Environmental Research.
The researchers evaluated imaging of 145 children at an average age of 12 years, looking specifically at the levels of myo-inositol found in the brain through a specialized MRI technique, magnetic resonance spectroscopy. Myo-inositol is a naturally-occurring metabolite mainly found in specialized brain cells known as glial cells, that assists with maintaining cell volume and fluid balance in the brain, and serves as a regulator for hormones and insulin in the body. Increases in myo-inositol levels correlate with an increased population of glial cells, which often occurs in states of inflammation.
They found that, among those exposed to higher levels of recent TRAP, there were significant increases of myo-inositol in the brain, compared to those with lower TRAP exposure. They also observed increases in myo-inositol to be associated with more generalized anxiety symptoms. "In the higher, recent exposure group, we saw a 12% increase in anxiety symptoms," says Brunst.
Brunst noted however, that the observed increase in reported generalized anxiety symptoms in this cohort of typically developing children was relatively small and are not likely to result in a clinical diagnosis of an anxiety disorder. "However, I think it can speak to a bigger impact on population health ... that increased exposure to air pollution can trigger the brain's inflammatory response, as evident by the increases we saw in myo-inositol," says Brunst. "This may indicate that certain populations are at an increased risk for poorer anxiety outcomes."
https://www.sciencedaily.com/releases/2019/05/190521162421.htm