Adding plants and trees to the landscapes near factories and other pollution sources could reduce air pollution by an average of 27%, new research suggests.
Reducing air pollution is critical to public health. The study shows that plants – not technologies – may also be cheaper options for cleaning the air near a number of industrial sites, roadways, power plants, commercial boilers and oil and gas drilling sites.
Researchers found that in 75% of the counties analysed, it was cheaper to use plants to mitigate air pollution than it was to add technological interventions – things like smokestack scrubbers – to the sources of pollution.
Bhavik Bakshi, lead author of the study and professor of chemical and biomolecular engineering at The Ohio State University, said: “The fact is that traditionally, especially as engineers, we don’t think about nature; we just focus on putting technology into everything.
“So, one key finding is that we need to start looking at nature and learning from it and respecting it. There are win-win opportunities if we do – opportunities that are potentially cheaper and better environmentally.”
Reducing air pollution with nature
The study, published today in the journal Environmental Science & Technology, found that nature-based solutions to air pollution might, in many cases, be better than technology at combatting air pollution.
The analysis found that for one specific sector – industrial boilers – technology is cheaper at cleaning the air than ecosystem upgrades. For the manufacturing industry both ecosystems and technology could offer cost savings, depending on the type of factory.
The researchers found that restoring vegetation to county-level average canopy cover reduced air pollution an average of 27%, however this figure varies by region depending on the type of environment – such as desert or farmland, for example.
Their research did not calculate the direct effects plants might have on ozone pollution, because, Bakshi said, the data on ozone emissions is lacking. The analysis also didn’t consider whether certain species of trees or plants would better ‘scrub’ pollution from the air, though Bakshi said it is likely that the species of plant would make a difference in air quality.
They found that adding trees or other plants could lower air pollution levels in both urban and rural areas, though the success rates varied depending on, among other factors, how much land was available to grow new plants and the current air quality.
Bakshi said their findings indicate that nature should be a part of the planning process to deal with air pollution, and show that engineers and builders should find ways to incorporate both technological and ecological systems.
“The thing that we are interested in is basically making sure that engineering contributes positively to sustainable development,” Bakshi said.
“And one big reason why engineering has not done that is because engineering has kept nature outside of its system boundary.”