What Lies Underneath: Germs Straphangers Carry

Monday, January 02, 2012


New Yorkers are known for schlepping bags: brief cases, luggage, backpacks, lady totes or man-purses. Plenty of them end up on a subway floor during a crowded commute.

What's lurking on the bottom of those bags? Plenty, if you ask Doctor Philip Tierno, director of Microbiology at the NYU Langone Medical Center and professor of Microbiology at the NYU School of Medicine.

"The skin, feces, and feces is the #1 source, respiratory tract organisms, as well as environmental organisms,” he said.

That may come as no surprise to many of us, yet there is no shortage of people storing their belongings on the subway car floor so they don’t take up an extra seat.

On a recent F train commute to Manhattan, Brooklyn resident Dave Peterson stashed his bright yellow duffel bag under his seat.

He said he often doesn’t have a choice. But he said he checks first.

“I always look at the ground before I put it down on the ground I make sure I’m not putting it in something,” he explained.  “I probably wouldn’t put it down if it looked dirty or something.”

But what could make someone ill isn’t always apparent to the naked eye.

In his 42 years on the job, Dr. Tierno has tested a couple of hundred bags. He said only between 1 and  3 percent of them carried a pathogen that could make someone really sick.

Still, he recommends New Yorkers clean the bottom of their bags with a disinfectant, if it has spent any time sliding around the subway or a city sidewalk. He said it should be similar to the household hygiene you practice.

“I would do it each day — in other words when you get to your home just wipe the bottom of the bag with a wipe. Simple...its not that bad. And if you can't afford a wipe, a little bit of chlorine in water, maybe a whiskey glass full in a quart of water, that’s the best germicide available. And the cheapest.”

Tierno said alcohol and tea tree oil are also good cleaners and won't damage leather bags.

Queens resident and 1 Train rider Toyin Onanuga said she already practices good bag hygene. “I walk around with sanitizer. Every time I put it on the floor, I wipe it off. I’m not taking any chances!”

But fellow 1 train passenger Manhattan resident Renee Murray said you couldn’t pay her enough to let her precious purse touch the ground.

“I would never do it…The train is full of a lot of germs and you should be cautious that’s how you can get an infection,” she said.

The black tote bag I’ve been carrying for a year has done more than a little time on the floor of the subway. So, Dr. Tierno tested it to see what it might be carrying.

In addition to carrying around hand cream, notebooks and mints in my bag, Tierno said the test revealed I was also carrying Rhodotorula species, Aspergillus species and Bacillus subtilis — two bacteria and one fungus — on the bottom of the bag. But he said the total count was relatively low.

Let’s just say it’s since been cleaned.

You can listen to an interview with Dr. Tierno above.

Kathleen Horan/WNYC
Dr. Phil Tierno Prepares to test my bag.
Kathleen Horan/WNYC
Dr. Tierno swabs the bottom of bag.
Kathleen Horan/WNYC
Bag on subway platform.
Bag on subway car floor.
Kathleen Horan/WNYC
Kathleen Horan/WNYC


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Comments [11]


well: duh,okay,but people don't think about this stuff. so "the duh of common" sense, might just not hit home, until explained by a scientific person. much too many seemingly obvious and mundane realities, are simply taken for granted.

Jan. 02 2012 11:56 PM
luap silopek


Jan. 02 2012 11:26 PM
Yuliya from Brooklyn

How about using handlebars in the subway or bus? Somebody might have coughed into their hand just before grabbing that handlebar. Even if you are going to wash you hands when you get home, you might tough you face before that. Or somebody might simply cough or sneeze in you face. That's why sickness travels around.

Jan. 02 2012 10:56 PM

they wash subway floors several times a day, don't they? At the end of each run? I've seen them doing this at Coney island before they let the train leave

Jan. 02 2012 07:37 PM
Obbop from Missouri

I do not live where a subway system exists nor do I use the local buss-based public transit.

However, when I worked in the locally-owned small grocery store with an in-store small deli I practiced excellent hygienic procedures to minimize any possibility of transmitting germs, viruses, etc.

To me that was basic common-sense and courtesy.

Sadly, so many of the human herd are either unaware of the need to take care or do not care or are too lazy to take the needed steps.

Knowing this and that too many restaurants are too lax I have refrained from eating outside the shanty where I am in control of the hygiene.

Oh, sure, I do eat out from time-to-time but looking around a food purveying firm can indicate which ones are likely to be a bit on the "cleaner side."

One of the local all-you-can-gulp buffets appears to practice "safe sating" and I am glad since I revel in the many food-types offered.

Jan. 02 2012 04:24 PM
EBW from Manhattan

Are you sure that wasn't Mel Brooks as the 2,000 year old man?

Jan. 02 2012 02:50 PM
inwoodita from nyc

I never put my bag down, I always use bags with handles long enough to hook it over my knee. I have a lot of trouble explaining to my BF why I'd prefer he not put our bags on the floor. Maybe this article will convince him!

Jan. 02 2012 10:50 AM
clive betters

of course, don't put it on the seat next to you,because you'll get a ticket,even if there are only two other people in the subway car.

Jan. 02 2012 09:45 AM
Katalin from Jersey City

I have never seen so many people sitting on the floors of public spaces and so many bags put on the floors of the dirtiest subway cars and platforms as here in New York. I find myself bothered by this unprecedented filth and grime and would never consider resting my bags on the floor. For these practices coupled with the habit of not taking one's shoes off when at home and putting bags onto one's lap or kitchen counter gross is an understatement. Nevertheless, many city people would be grossed out if they had to get their hands dirty while maneuvering with raw natural products like dirt, mud or manure.

Jan. 02 2012 08:12 AM
Marian S. from Manhattan

How are our bags any different from our shoes? Why doesn't he advise us to wipe off the bottoms of our shoes? BTW, the bag I place on subway floor I never place on any table or other surface except a floor. I treat it the same way I treat my shoes: floor only.

Jan. 02 2012 07:35 AM
Claude from Westchester

This is a timely report for me and take these suggestions as "words to the wise". However, I will not limit to subway trips but other trains and especially airlines. I have often wondered if putting our bags and especially personal bags on these floor surfaces was innocent. Lastly it has always amazed me that some think nothing of placing their purses in a medical office or even hospital room floor. Thanks to this report I am now very clear on the possibilities for all of these practices.

Jan. 02 2012 06:45 AM

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