Neuroimaging connects air pollution to childhood anxiety

New evidence suggests air pollution may have a negative impact on the neurological development of children, according to a new neuroimaging study published in Environmental Research.

"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," lead author Kelly Brunst, PhD, assistant professor in the Department of Environmental Health at the University of Cincinnati College of Medicine said, in a prepared statement.

To investigate the correlation between exposure to traffic-related air pollution (TRAP), Brunst and colleagues imaged 145 children with an average age of 12 years using MR spectroscopy performed at the University of Cincinnati and Cincinnati Children's Hospital Medical Center.

Specifically, the researchers looked at levels of myo-inositol found in the brain. Myo-inositol is a naturally-occurring metabolite found in brain cells called glial cells, which act as a regulator for hormones and insulin. Increased levels of myo-inositol can occur due to inflammation and are connected with an increase of glial cells.

The researchers found myo-inositol levels were significantly higher in the brains of patients exposed to higher levels of recent TRAP, compared to those exposed to lower levels of pollution. Additionally, the team found increases in myo-inositol were associated with more generalized anxiety symptoms.

"These findings suggest that the neurotoxic effect of high TRAP exposure on generalized anxiety is partially (12%) due to increases in myo-inositol," Brunst noted.

Brunst pointed out, however, that the increase in reported generalized anxiety symptoms in these “typically developing” children was relatively small and “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," Brunst added. "This may indicate that certain populations are at an increased risk for poorer anxiety outcomes."

The National Institutes of Environmental Health Sciences and the National Center for Advancing Translational Sciences provided funding for this study.