We've recently planted a lot of Sans Severias because my mom told me that they clean up the air around the house. I'm not so sure as to how such a small plant (or is it a weed) can clean up the air.
check the data on NASA experiment. I believe you have to plant lots of pots to purify a big area. There is a requirement of how many plants/area to make it work.
Any houseplant uses carbon dioxide for photosynthesis, meaning plant uses your fart, and excess aerosol to make their food. So the effect, less carbon dioxide in your home since plant use it, and replace it with oxygen for you to breath.
good question :)