Just about every paper on the subject, and I mean literally all of them, are based on a 1989 NASA study and a follow up by the lead scientist.

The scientists collected plants and put them in chambers, then pumped in harmful chemicals like these.

(Ammonia, Trichloroethylene, Formaldehyde, Xylene, Benzene)

After 24 hours, they tested the air quality in each chamber.

Some plants were able to remove up to 90% of the harmful chemicals.

So which plants were the most effective?

NASA scientists tested familiar ones.

All the plants they have in their list are just very common house plants.

This is Dr. Dennis Stevenson, Vice President for science at the New York Botanical Garden.

I think they picked them because they were looking at things that people would have in their environments.

As opposed to some exotic, weird tropical plant that nobody knows anything about.

All of these plants are excellent at getting rid of harmful indoor carcinogens.

(Boston fern, gerbera daisy, peace lily, snake plant, Chinese evergreen)

(Carcinogen: an agent that can cause cancer in humans.)

Here's how it works:

Plants take in the harmful gasses out of the atmosphere and sequester them in their roots and cells.

Some of these chemicals are broken down by fungi in the soil and others are stored in the plant.

So what about things like...smoke, that might be in your apartment via cigarettes.

Or you know...other types of smoke.

Well I would say, they take up stuff in the atmosphere so theoretically they should take up any kind of smoke that's in your apartment in a certain sense, right.

I don't really know.

But I think if one did those tests that probably one would find a positive correlation with that.

(Positive correlation between plants and removing smoke.)

Of all of the plants NASA mentioned in its study, these three have the best surface area to chemical removal ratio.

(gerbera daisy, English Ivy, snake plant)

But keep in mind that a gerbera daisy will never get as big as a lady palm.

And the more plant you have, the more harmful chemicals that you can remove.

A big leaf plant is probably, potentially able to exchange more things with the air you know than something with little needle leaves.

And for those lacking a green thumb?

I'll tell you, the one in there that's probably the hardest to kill is the sansevieria, the mother in law's tongue.

It scores high on removing chemicals and only needs low light.

Hello everyone, if you'd like to learn more about the plants or the experiments done by NASA, check out the description below.

You'll find a more detailed account of which plants are mentioned at the beginning of the video.

If you're looking to buy some of these plants or want to learn how to take care of them, don't forget to check out your local nursery.