Research in 4 continents links outdoor air pollution to differences in children’s brains

Outdoor air pollution from power plants, fires and cars continues to degrade human, animal and environmental health around the globe. New research shows that even pollution levels that are below government air-quality standards are associated with differences in children's brains.

A UC Davis research team systematically analyzed 40 empirical studies, the majority of which had found that outdoor air pollution is associated with differences in children's brains. These differences include volumes of white matter, which is associated with cognitive function, connections throughout the brain and even early markers for Alzheimer's.

The study, "Clearing the Air: A systematic review of studies on air pollution and childhood brain outcomes to mobilize policy change," was published this month in Developmental Cognitive Neuroscience.

"We're seeing differences in brain outcomes between children with higher levels of pollution exposure versus lower levels of pollution exposure," said Camelia Hostinar, an associate professor of psychology and the study's corresponding author.

Children and teens are especially vulnerable to air pollution because their brains and bodies are still developing. They tend to spend more time outdoors, and their bodies absorb more contaminants relative to their bodyweight than adults, researchers said.

Outdoor air pollution and brain development

This study surveyed 40 published, peer-reviewed studies that all included measures of outdoor air pollution and brain outcomes for children at various ages, from newborns up to 18-year-old adults. The majority of studies came from the United States, Mexico and Europe, with one each from Asia and Australia.