A new DNA mapping study focused on the NYC subway system reveals a lot about the bacteria down there.

The DNA mapping study encompassed 466 NYC subway stations and looked at the different bacteria’s living in them. The study found that many of the stations contained bacteria that are behind several diseases as well as food poisoning and other viruses.

The study found that there was DNA from 15,000 organisms and half of the DNA discovered couldn’t be matched to any known organisms. One of the stations that was studied had been flooded by Hurricane Sandy and looks like a marine environment despite being dry.

The researchers behind the study were also able to use genetic markers to identify the races using the NYC subway for travel. It compared the data to data from the U.S. Census and found that it matched up to it.

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