More than 131 million people live in places with unhealthy air quality, according to the American Lung Association’s 2024 State of Air report. This is an increase of 11.7 million people from the previous year. The report also finds that the number of days with “very unhealthy” or “hazardous” air quality in the United States was the highest in 25 years.
There are myriad health problems associated with air pollution, including lung conditions, heart disease, cancer, damage to neurological and reproductive systems, and diabetes. Now, a new systematic review is taking a careful look at the impact of air pollution on children’s brains.
The review, published this month in the journal Developmental Cognitive Neuroscience, combined the results of 40 different studies to examine the connections between air pollution exposure and brain outcomes in infants and children up to 18 years old.
The studies were conducted in the U.S., Mexico, Europe, Asia, and Australia. They each included measures of participants’ brains using a variety of methods including imaging technology such as MRI or DTI; four of the studies examined the brains of deceased participants in autopsies. Each study also included measures of air pollution linked to the participant’s address or neighborhood.
On the whole, the review found a link between exposure to outdoor air pollution and differences in children’s brains, including lower volumes of white matter, poorer functional connections in brain networks, tumors, and early markers for Alzheimer’s disease.
“We’re seeing differences in brain outcomes between children with higher levels of pollution exposure versus lower levels of pollution exposure,” said Camelia Hostinar in a press release. Hostinar is a psychologist at the University of California, Davis and the study’s senior 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 body weight than adults’.
In addition to making a connection between pollution and children’s brains, the review article suggests steps to combat the problem. The best action is to reduce air pollution by doing away with coal-fired power and vehicles that emit greenhouse gases, the review said.
In the short term, the authors suggest installing air-monitoring sensors near known sources of pollutants and providing government subsidies to pay for air filters, especially in schools, homes, and workplaces in areas with poorer air quality. The researchers also suggest that future studies related to brain health include measures of air pollution, which can be as simple as reporting participants’ addresses.
The take-home message: Air pollution harms the brains of young people. Identifying sources of air pollution and using air filters to help reduce indoor pollution levels are two ways to address the problem in the short term.
