What can green streets not do? They can beautify streetscapes and increase walkability; they can reduce crime; they can save cities money; they can reduce accidents; and, according to a new research study led by Professor Thomas Pugh at Lancaster University, we learn that, "adding trees, bushes, innovative systems like green walls, or even ivy or other creeping vines, can cut street-level nitrogen dioxide (NO2) and microscopic particulate matter (PM), two of the worst forms of pollution, by eight times more than previously thought," reports the ALSA's The Dirt blog.
"Green walls in particular could be used to further increase the amount of pollutant-absorbing foilage [sic] available in these spaces [what the authors call 'urban street canyons']. Co-author Rob MacKenzie from the University of Birmingham told BBC News: 'The benefit of green walls is that they clean up the air coming into and staying in the street canyon. Planting more [green walls] in a strategic way could be a relatively easy way to take control of our local pollution problems.'"