A new study conducted by researchers from Weill Cornell Medical College actually mapped out the bacteria covering New York's subway system in a project called 'PathoMap,' and the results were the stuff of nightmares. The scientists found hundreds of species of bacteria, while about half of the DNA found were from organisms they couldn't even identify.
The Wall Street Journal's Robert Lee Hotz reports:
Dr. Mason and his research team gathered DNA from turnstiles, ticket kiosks, railings and benches in a transit system shared by 5.5 million riders every day. They sequenced the genetic material they found at the subway's 466 open stations -- more than 10 billion fragments of biochemical code -- and sorted it by supercomputer. They compared the results to genetic databases of known bacteria, viruses and other life-forms to identify these all-but-invisible fellow travelers.
In the process, they uncovered how commuters seed the city subways every day with bacteria from the food they eat, the pets or plants they keep, and their shoes, trash, sneezes and unwashed hands. The team detected signs of 15,152 types of life-forms.
Of the identified organisms, the scientists found "1,688 bacterial, viral, archael, and eukaryotic taxa." One subway station which had been flooded during Hurricane Sandy still resembled a "marine environment."
"People don't look at a subway pole and think, 'It's teeming with life,'" said Dr. Christopher E. Mason, a geneticist and lead author of the study in an interviewwith the New York Times. "After this study, they may. But I want them to think of it the same way you'd look at a rain forest, and be almost in awe and wonder, effectively, that there are all these species present -- and that you've been healthy all along."