What do green walls really do? #shorts #science #SciShow

Traffic emits pollutants harmful to health, but plants can mitigate this by absorbing particles and using dry deposition. They also act as physical barriers, dispersing pollutants and reducing exposure. Trees are effective, but green walls can also help in limited spaces.

Why are trees considered effective in reducing exposure to pollutants?

What alternative can be used if there is not enough space for trees?