The beginning of a new school year means kids are spending half — or more — of their waking hours packed into schoolhouses, many of which are in heavily trafficked urban areas or in more-densely-packed areas of town. In fact, some 6.4 million students in the U.S. attend school within 250 meters of a major roadway, exposing them to heightened levels of traffic-related air pollution.
For kids especially, this is risky business. Not only are children’s brains and bodies still growing, their daily activities make them more vulnerable to pollutants. Kids breathe more rapidly than adults do, they consume more water relative to their body size, and they spend a greater portion of their time outdoors.
All that adds up to a bigger opportunity for pollutants and particulate matter to get into the lungs and bloodstream — and eventually into the brain. Pollutants, doctors have found, contribute to inflammation in the brain, which can cause loss or damage to tissue and impact neurons’ ability to communicate with one another.
Here’s what that can mean for a child’s learning ability, mental health, and physical health:
Researchers have repeatedly shown a connection between air pollution and slowed learning. Last year, for example, a Spanish study made headlines when it found that children attending schools in close proximity to major roadways were behind others in key areas of development, including memory and attentiveness. An Italian study linked infant exposure to nitrogen dioxide from car exhaust to decreased verbal skills in elementary school. And, earlier this month, a team at Lancaster University identified magnetite particles — a substance commonly found in diesel exhaust — lodged in human brain tissue; though more research is needed, the particles are associated with degenerative neurological diseases.
Over the summer, a team of Swedish researchers demonstrated a link between traffic-related air pollution and increased mental illness in people under 18 years old. The team mapped the pollutant exposure of a half-million young people against how often they were prescribed medications that treat mental illness, and found that those with greater exposure were more likely to be treated for psychiatric conditions down the line.
The findings are consistent with past studies. A 2012 Columbia University study, for instance, found that in-utero exposure to particulate matter levels common in most big cities lead to depression, anxiety, and attention issues later in life. And a study from Ohio State University found that mice that were exposed to high levels of pollution acted more anxious than those who breathed cleaner air.
Prolonged exposure to air pollution has perhaps its greatest impact on a child’s respiratory health. Over the past three decades, numerous studies have drawn direct links between traffic-related pollution and asthma, chronic coughs, and bronchitis. It’s not all bad news, however, research does also indicate that the effects can be reversed if children move to or spend considerable time outside dense urban areas.
Uprooting, however, is an extreme option. But actively seeking out cleaner air in green spaces — or taking steps to scrub pollution from our homes with air purifiers— can help ensure kids have the opportunity to grow and thrive.