There may be up to 15,000 life forms – from anthrax to the bubonic plague – living in the New York City subway system, according to a new study.

The New York underground

The New York underground. Image by Don Dilworth / CC BY 2.0

Scientists at Weill-Cornell Medical College used nylon swabs as a way of collecting DNA samples across 466 subway stations, Fox News, New York reports.

Then, by employing a super-computer, they managed to connect 10 million pieces of bio-code to the various life forms they had collected.

Remnants of such things as pizza and chickpeas (humus) on platforms and benches were also discovered in the study.

However the New York City Health Department described the study as ‘deeply flawed’ and stressed that the subway system was no danger to public health.

Over 250 million people use the subways on an annual basis.