A filter can remove up to two thirds of all particulates claims its developer (Dutch), Bob Ursem of the Technical University of Delft. Particulates are tiny particles of anything floating in the air, be it sand, salt, sulfuric acids, nitric acids, and so on, and are considered a health hazard.
Ursem’s invention works by electrically charging the particles. A negatively charged mesh, or anything that is grounded, will then attract the particles. Something as simple as a plant could act as the mesh.
Unfortunately, Ursem has patented his invention, so even if it works (two thirds of how much air?), it may not be deployed widely for the next 15 years or so.