In my parents house where i grew up back in the days, my father always used to have a corner in the living room, which was stacked with huge nice plants that he cared for.
This aside from the plants that were all over the house. i didn’t pay much attention to it at that time, but i am sure glad that he did:)))
official study done by NASA in 1989, read the report online at archive.org:
or download the report as pdf file here:
NASA clean air study