Still following the post above about the biodiversity hypothesis that connects weakened immune systems and urban environments, a condition which is aggravated for contaminated indoor air, see below image taken from a chapter in a book published almost 10 days ago:
"Active
botanical biofiltration systems can be supplied air by three different
methods; passing air over the foliage, passing air behind a vertical green
wall, in the space between the substrate and the surface onto which the
plants are attached, and passing air through the substrate via a
pressurized plenum...The increased plant density, vertical alignment with
minimal use of floor space, exposure of the substrate to the atmosphere… are
all major technological advancements from the original phytosystems tested by
NASA...”
