Trees and bushes near highways improve air quality

Anyone who’s endured rush-hour bumper-to-bumper traffic knows how unpleasant the air can get. Between fumes, dust, and all those exhaust pipes, it’s definitely not a nature lover’s paradise. But what if those trees and bushes lining our highways weren’t just there for decoration?

What if they were secretly cleaning the air you breathe? Well, a new study from Georgia State University says they just might be.

The power of trees

We all know trees are vital for the environment. They turn carbon dioxide into oxygen and give us shade – essentials for the planet. However, scientists have uncovered another lesser-known benefit of roadside greenery, and it may have you looking at those leafy medians in a whole new light.

“Trees and bushes near roadways don’t solve the problem of air pollution caused by motor vehicles, but they can help reduce the severity of the problem,” said Roby Greenwald, lead researcher on the study.

Trees near highways

Think of plants along the highway as a giant, organic filter system. Their leaves and branches create a massive surface area. Air pollution particles, some so tiny you couldn’t even see them individually, get trapped on these surfaces, effectively taking them out of circulation. These include:

• Soot: Those black, carbon-filled particles that turn your fingers grimy if you live in a polluted city.
• Ultrafine particles: Microscopic nasties invisible to the naked eye, but they can do serious damage to your respiratory system if you breathe them in over time.

The Georgia State study measured the air quality around busy Atlanta highways, comparing sites with plentiful trees to those without.

Impressively, they found a 37% reduction in soot and a 7% reduction in ultrafine particles where trees and bushes were present.

The health connection

Air pollution is a bad news for our health. “A growing body of evidence has linked motor vehicle pollution to conditions such as asthma, chronic bronchitis, lung cancer, and heart attacks,” said Greenwald.

It’s especially worrying for the 45 million Americans living, working, or studying within a stone’s throw of a major highway. Children are particularly vulnerable, as their lungs are still developing.

So, anything that helps reduce their exposure, even a little, is a win for public health.

Not a miracle solution

While this is fantastic news, it’s important to be realistic. Trees aren’t going to magically make all our pollution problems go away. “Trees and bushes near roadways don’t solve the problem of air pollution caused by motor vehicles, but they can help reduce the severity of the problem,” said Greenwald.

Greenwald emphasizes that for a truly comprehensive approach, we need to tackle the root cause of the problem: our dependence on cars. This means making public transport more accessible and convenient, and investing in better cycling and pedestrian infrastructure.

Getting people out of their cars and onto bikes or buses is the ultimate way to improve air quality for everyone.

Planting trees alongside highways

So, the next time you’re stuck in traffic, give a little thanks to those unassuming trees along the road. They’re working hard to make your commute that tiny bit healthier. As Greenwald noted: “We should plant more trees along roadways because they provide benefits that go beyond aesthetics.”

This doesn’t excuse us from finding real ways to ditch our car dependency. However, sometimes progress happens in small steps, and every cleaner breath we take thanks to some strategically placed greenery is a step in the right direction.

The study is published in the journal PLOS ONE.

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