There was an art project a couple of years ago to clean up smog. https://www.studioroosegaarde.net/project/smog-free-project https://www.studioroosegaarde.net/

There was an art project a couple of years ago to clean up smog. https://www.studioroosegaarde.net/project/smog-free-project https://www.studioroosegaarde.net/project/smog-free-project