IRA FLATOW: If you ride mass transit, do you think twice about reaching for that pole or the handle? We all know that they are covered in germs. You know. A toddler with his thumb in his mouth, he grabs a subway pole, and there’s a sticky string of saliva left. A woman sneezes, and blankets the entire train in itty bitty microbes.

Well, we who ride in the subway know it’s not for germaphobes, so you won’t be there. But how many riders do you know go out in search of subway bacteria? Craig Ward does. And he’s been taking advantage of the subway bacterial brew to make art. Emily Driscoll brings us that story in our latest sci-fi video. Welcome back Emily.

EMILY DRISCOLL: Thanks, happy to be here.

IRA FLATOW: For somebody who was gone on the subway, and I’ve seen the video, it’s wonderful. And Craig decided to go out, and swap the subway.

EMILY DRISCOLL: Exactly. The inspiration for the project came when he looked at a photograph taken by researcher Tasha Strum. And she put her son’s hand prints in a Petri dish, and grew the bacteria. And took a photo of it. So it was bacteria in the shape of her son’s handprint. Plus, he was interested in this myth that he heard that holding the hand rails on the subway is like shaking hands with 100 people at the same time. Plus, his interest in typography, and subway type, all of these three factors together inspired the project.

IRA FLATOW: Well, what do the artworks look like? They’re very colorful. Beautiful, you don’t think that bacteria could do this kind of stuff.

EMILY DRISCOLL: Absolutely. So in the Petri dishes, he takes a sponge that is in the shape of the subway, letter or number. So the L train for example, he’ll take an L-shaped sponge. The bacteria will grow in an L shape. But they’re very beautiful. He describes them as little worlds. They look like sea life, or even stars, or little flowers. Very beautiful until you look a little closer, and see what you’re actually looking at.

IRA FLATOW: Talking with Emily Driscoll about her Science Friday video on Science Friday from PRI, Public Radio International. Now I know that you went out, because I see it in the film. You went out watching him swab subway poles.

EMILY DRISCOLL: I did.

IRA FLATOW: What did the people in the subways think was going on? And how did they react?

EMILY DRISCOLL: Oh, yeah, it was a blast. He was swabbing the seats and the hand rails, and if there was a greasy spot on the window in the car. And everybody was giving him a side eye. So it was pretty awkward. And he describes that awkward experience in the video too.

CRAIG WARD: You can get away with most things on the subway, but I feel like as soon as you start getting out scientific equipment, people want to raise their eyebrows, and maybe shuffle down the seat a little bit. Which is crazy considering the stuff you do deal with on the subway. I would just try and get it done as quickly as possible. It was a little uncomfortable.

IRA FLATOW: But New Yorkers they just let everything wash right over them, right?

EMILY DRISCOLL: Yeah.

IRA FLATOW: Now, has he been able to identify any of the bacteria?

EMILY DRISCOLL: Yes, he works with scientists. So he didn’t do any scientific testing himself, but he did a visual identification. And he found a lot of benign bacteria, but he did fine E. coli, salmonella, staph, strap, and sepsis. And at the same time, Doctor Chris Mason, at Weill Cornell Medical College, he did a massive study– he and his team– called the pathomap projects. And they looked at more than 400 stations around New York City. And they extracted DNA from more than 15,000 types of life forms. Only half of which have ever been identified. So we don’t know what half of those 15,000 are.

IRA FLATOW: Wow.

EMILY DRISCOLL: And he found the same sort of thing. Their results were pretty much in line with the E. coli, salmonella, staph, strep, and salmonella.

IRA FLATOW: Did he find any strange ones that no one expected it to be there?

EMILY DRISCOLL: Yeah, he found a lot associated with food, actually. Bacteria associated with mozzarella, and kimchi, sauerkraut, and even the South Ferry Station, it was flooded by Hurricane Sandy. So that kind of looked like a marine underwater environment, based on the bacteria. And they found species that are often found in –and they thrive– in Antarctic waters.

IRA FLATOW: Oh, my God.

EMILY DRISCOLL: Yeah.

IRA FLATOW: Well, we know that New York is a diverse place. But didn’t realize the fact the biome, the microbiome in New York subway was such a diverse place. Are we the only city where the subway bacteria [INAUDIBLE]?

EMILY DRISCOLL: No, not for long. Chris Mason is building on this project. So he’s doing a global version of pathomap, which is called MetaSUB. And so he’s looking to build molecular profiles of other cities like Shanghai, Moscow, Paris, Sao Paulo, 45 cities so far.

IRA FLATOW: Should we be fearful that the same bacteria he has is the same stuff we’re going to get if we go in the subways? Or what happens to the bacteria?

EMILY DRISCOLL: Well, most of the bacteria– it doesn’t last very long, because of the metal on the subway. They do clean the subways, actually. So the bacteria, they would only survive for a couple of hours. So these portraits that he’s taking really are a snapshot of the commuters on a particular day and time in subway line.

IRA FLATOW: What does he do with the Petri dishes? I mean, you don’t want to keep growing staph, and strep, and salmonella in your home.

EMILY DRISCOLL: Yeah, he photographs them. And then, for us, we got to see that. And we made sure to have a lot of Purell handy that day. But then he photographs them, and discards them in a proper way. He consults with scientists on that.

IRA FLATOW: Did you have a yuck factor when you were filming this?

EMILY DRISCOLL: It was more intriguing. But they’re so beautiful too. So it was really fascinating.

IRA FLATOW: They are really beautiful. And the film is very beautiful, Emily. Thank you.

EMILY DRISCOLL: Thank you.

IRA FLATOW: Thank you for producing it. Emily Driscoll is a science documentary producer based here in New York. And you can watch her video Sub Visual Subway, at sciencefriday.com. It really is cute. Thank you very much.

EMILY DRISCOLL: Thank you.

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