Potted plants do not improve indoor air quality

They do remove VOCs, but you basically need to be living in an indoor jungle with 10-1000 plants per square metre.

Back in the 80's I remember visiting the home of the town mayor that had a lounge room sized atrium overflowing with ferns in the centre of the house (basically an indoor greenhouse) that could be accessed from each room. Doesn't sound like that will do as much as you might hope for.

I thought a result that was 'insignificant' meant that it was not possible to tell if it was an improvement or sampling noise?

Have you read that NASA study? It involves air being run through an activated carbon filter, and the plants using that carbon filter as its growing medium. From the paper:

> This air filter design combines plants with an activated carbon filter as shown in Figure 1. The rationale for this design, which evolved from wastewater treatment studies, is based on moving large volumes of contaminated air through an activated carbon bed where smoke, organic chemicals, pathogenic microorganisms (if present), and possibly radon are absorbed by the carbon filter. Plant roots and their associated microorganisms then destroy the pathogenic viruses, bacteria, and the organic chemicals, eventually converting all of these air pollutants into new plant tissue.

https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/199300...

This isn't how most people setup their house plants.

Kamal Meattle's primary result was demonstrating increased blood oxygen levels in occupants of buildings with large numbers of plants. This is consistent with the results of the study finding pollutants not filtered from the air. Additionally it is worth noting that achieving that result required not only large numbers of plants, but extensive care for the plants. The requirement that the plants be frequently cleaned of dust to keep their pores open may also be involved with the results. In any case, all these studies agrees that large numbers of plants are required to generate detectable results.

Oh, I see what you mean! In the UK, "potted" plants are actually called pot plants more often than not.