DNA floating in the air tracks wildlife, viruses -- even drugs

But it's not just music floating on the breeze. The air of Dublin also contains cannabis, poppy, even magic mushrooms -- at least their DNA.

That's according to a new study that reveals the power of DNA, vacuumed up from the air, which can track everything from elusive bobcats to illicit drugs.

"The level of information that's available in environmental DNA is such that we're only starting to consider what the potential applications can be, from humans, to wildlife to other species that have implications for human health," said David Duffy, Ph.D., a professor of wildlife disease genomics at the University of Florida and lead author of a new study showing the widespread utility of DNA vacuumed from the air.

Housed at UF's Whitney Laboratory for Marine Bioscience, Duffy's lab developed new methods for deciphering environmental DNA, also known as eDNA, to study sea turtle genetics. They've expanded the tools to study every species -- including humans -- from DNA captured in environmental samples like water, soil and sand.

But these errant strands of DNA do not just settle into muddy soil or flow along rivers. The air itself is infused with genetic material. A simple air filter running for hours, days or weeks can pick up signs of nearly every species that grows or wanders nearby.

"When we started, it seemed like it would be hard to get intact large fragments of DNA from the air. But that's not the case. We're actually finding a lot of informative DNA," Duffy said. "That means you can study species without directly having to disturb them, without ever having to see them. It opens up huge possibilities to study all the species in an area simultaneously, from microbes and viruses all the way up to vertebrates like bobcats and humans, and everything in between."

As a proof of concept, the researchers showed that they could pick up signs of hundreds of different human pathogens from the Dublin air, including viruses and bacteria. Such surveillance could help scientists track emerging diseases. The same method can track common allergens, like peanut or pollen, more precisely than is currently possible, the scientists discovered.

In another test of the power of eDNA, Duffy's lab was also able to identify the origin of bobcats and spiders whose DNA was hoovered up from air in a Florida forest. With little more than an air filter, scientists could track endangered species and identify where they came from, all without having to lay eyes on skittish animals or root around forest floors for scat samples. When trying to save and conserve wildlife, knowing where an animal originates from can be as important as knowing where it currently is.

This powerful analysis was paired with impressive speed and efficiency. The team demonstrated that a single researcher could process DNA for every species in as little as a day using compact, affordable equipment, and software hosted in the cloud. That quick turnaround is orders of magnitude faster than would have been possible just a few years ago and opens up advanced environmental studies to more scientists around the world. The same tools can potentially identify sensitive human genetic data, which is why Duffy and his collaborators have called for ethical guardrails for the rapidly developing field of eDNA.

"It seems like science fiction, but it's becoming science fact," Duffy said. "The technology is finally matching the scale of environmental problems."