Human DNA is everywhere. This is a boon for science — and a moral quagmire — ScienceDaily

We cough, spit, scrape and wash our DNA in all of these places and so much more. Signs of human life can be found almost everywhere, except on isolated islands and remote mountaintops, according to a new study from the University of Florida.

This ubiquity is both a scientific boon and an ethical dilemma, say the UF researchers who sequenced this ubiquitous DNA. The DNA was of such high quality that scientists were able to identify mutations associated with the disease and determine the genetic origin of nearby populations. They can even match genetic information with individual participants who volunteered to recover faulty DNA.

Ethically handled environmental DNA samples could benefit the fields of medicine, environmental sciences, archeology and forensics, says David Duffy, the UF wildlife disease genomics professor who led the project. For example, researchers can track cancer mutations from wastewater or locate undiscovered archaeological sites by checking for hidden human DNA. Or, investigators could identify suspects from DNA floating in the air at a crime scene.

But this level of personal information must be handled with extreme caution. Now, scientists and regulators must grapple with the ethical dilemmas inherent in accidentally — or intentionally — collecting human genetic information not from blood samples but from a scoop of sand, a bottle of water, or a person’s breath.

Posted May 15 in Ecology and evolutionThe paper by Duffy’s group outlines the relative ease of collecting human DNA nearly everywhere.

“We were constantly surprised throughout this project by the amount of human DNA we found and the quality of that DNA,” Duffy said. “In most cases, the quality is roughly equivalent to if you sampled someone.”

Because of the ability to potentially identify individuals, researchers say ethical protection barriers are necessary for this type of research. The study was conducted with UF Institutional Review Board approval, ensuring ethical guidelines were adhered to during research studies.

“It’s the norm in science to make these sequences publicly available,” Duffy said. “But that also means if you don’t withhold human information, anybody can come and collect that information.” “This raises issues around consent. Do you need to get consent to take those samples? Or put some controls in place to remove human information?”

Duffy’s team at the Whitney Marine Biosciences Laboratory and Sea Turtle Hospital of F. They extracted beneficial DNA from turtle tracks in the sand, greatly speeding up their research program.

The scientists knew that human eDNA would end up in their turtle samples and possibly many other places they looked. With modern genetic sequencing technology, it is now easy to sequence the DNA of every organism in an environmental sample. The questions were about how much human DNA was and whether it was intact enough to harbor useful information.

The team found high-quality human DNA in the oceans and rivers surrounding Whitney’s lab, near the city and far from human settlements, as well as in sand from isolated beaches. In an easy test by the National Park Service, researchers traveled to a part of a remote island that no one had visited. It was devoid of human DNA, as expected. But they were able to recover DNA from volunteer participants’ footprints in the sand and could sequence parts of their genomes, with permission from the anonymous participants.

Duffy also tested this technique in his native Ireland. Tracking Daffy along a river that runs through the city on its way to the ocean, he finds human DNA everywhere except for a remote mountain stream where the river begins, far from civilization.

The scientists also collected room air samples from a veterinary hospital. They recovered DNA matching the staff, the animal patient, and common animal viruses.

Now that it’s clear that human eDNA can be easily sampled, Duffy says it’s time for policymakers and the scientific community to take issues around consent and privacy seriously and balance them against the potential benefits of studying this faulty DNA.

“Anytime we make a technical advance, there are useful things that technology can be used for and in terms of things that technology can be used for. It’s no different here,” Duffy said. “These are issues that we try to bring up early so policymakers and the community have time to develop regulations.”