A new USC study involving 8,500 children across the country reveals that a form of air pollution, largely from agricultural emissions, is linked to poor learning and memory performance in children ages 9 and 9. 10 years.
The specific component of fine particulate air pollution, or PM2.5, ammonium nitrate, is also implicated in the risk of Alzheimer’s and dementia in adults, suggesting that PM2.5 may cause long-term neurocognitive damage. of life. Ammonium nitrate is formed when ammonia gas and nitric acid, produced by agricultural activities and the burning of fossil fuels, respectively, react in the atmosphere.
The findings appear in Environmental health perspectives.
“Our study highlights the need for more detailed research into particle sources and chemical components,” said senior author Megan Herting, associate professor of population sciences and public health at the Keck School of Medicine of USC. “This suggests that understanding these nuances is crucial for informing air quality regulations and understanding long-term neurocognitive effects.”
For the past few years, Herting has been working with data from the largest brain study conducted in the United States, known as the Adolescent Brain Cognitive Development Study, or ABCD, to understand how PM2.5 can affect the brain.
PM2.5, a key indicator of air quality, is a mixture of dust, soot, organic compounds and metals that come in a variety of particle sizes less than 2.5 micrometers in diameter. PM2.5 can penetrate deep into the lungs, where these particles can enter the bloodstream and cross the blood-brain barrier, causing serious health problems.
The burning of fossil fuels is one of the largest sources of PM2.5, especially in urban areas, but forest fires, agriculture, marine aerosols and chemical reactions are also important sources.
In 2020, Herting and colleagues published a paper looking at PM2.5 as a whole and its potential impact on children’s cognition, but found no relationship.
For this study, they used special statistical techniques to look at 15 chemical components in PM2.5 and their sources. That’s when ammonium nitrate, which is usually the result of agricultural and livestock operations, in the air emerged as the main suspect.
“No matter how we looked at it, alone or with other contaminants, the strongest finding was that ammonium nitrate particles were linked to worse learning and memory,” Herting said. “That suggests that PM2.5 in general is one thing, but for cognition, it’s a mixed effect of what you’re exposed to.”
For their next project, the researchers hope to look at how these mixtures and sources may relate to individual differences in brain phenotypes during child and adolescent development.
In addition to Herting, other authors of the study include Rima Habre, Kirthana Sukumaran, Katherine Bottenhorn, Jim Gauderman, Carlos Cardenas-Iniguez, Rob McConnell and Hedyeh Ahmadi, all of the Keck School of Medicine; Daniel A. Hackman of the USC Suzanne Dworak-Peck School of Social Work; Kiros Berhane of Columbia University Mailman School of Public Health; Shermaine Abad of the University of California, San Diego; and Joel Schwartz of the Harvard TH Chan School of Public Health.
The research was funded by grants from the National Institutes of Health. [NIEHS R01ES032295, R01ES031074, P30ES007048] and the Environmental Protection Agency [RD 83587201, RD 83544101].