Human DNA is everywhere. That’s a boon for science and an ethical quagmire – ScienceDaily

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

That ubiquity is both a scientific boon and an ethical dilemma, say the UF researchers who sequenced this widespread DNA. The DNA was of such high quality that scientists were able to identify disease-associated mutations and determine the genetic ancestry of nearby populations. They could even match genetic information to individual participants who had volunteered to retrieve their errant DNA.

David Duffy, a UF professor of wildlife disease genomics who led the project, says ethically managed environmental DNA samples could benefit fields ranging from medicine and environmental sciences to archeology and criminal forensics. For example, researchers could track cancer mutations in sewage or detect undiscovered archaeological sites by searching for hidden human DNA. Or detectives could identify suspects from DNA floating in the air at the crime scene.

But this level of personal information must be handled very carefully. Now, scientists and regulators must grapple with the ethical dilemmas inherent in the accidental or intentional extraction of human genetic information, not from blood samples, but from a spoonful of sand, a vial of water, or a person’s breath.

Posted on May 15 in Nature Ecology and EvolutionDuffy’s group’s paper describes the relative ease of collecting human DNA almost everywhere they looked.

“We’ve been consistently 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 almost equivalent to if you take a sample from a person.”

Due to the ability to potentially identify people, the researchers say ethical guardrails are necessary for this type of research. The study was conducted with the approval of UF’s institutional review board, which ensures that ethical guidelines are followed during research studies.

“It’s standard in science to make these sequences publicly available. But that also means that if you don’t rule out the human data, anyone can come along and collect this data,” Duffy said. “That raises issues around consent. Do you need to get consent to take those samples? Or institute some controls to remove human data?”

Duffy’s team at the UF Whitney Laboratory for Marine Bioscience and Sea Turtle Hospital has successfully used environmental DNA, or eDNA, to study endangered sea turtles and the viral cancers to which they are susceptible. They have extracted useful DNA from turtle tracks in the sand, greatly accelerating their research program.

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

The team found quality human DNA in the ocean and rivers surrounding the Whitney Laboratory, both near the city and far from human habitation, as well as in the sand on isolated beaches. In a test facilitated by the National Park Service, researchers traveled to a remote part of an island never visited by people. It was free of human DNA, as expected. But they were able to recover DNA from the volunteer participants’ footprints in the sand, and were able to sequence parts of their genomes, with the permission of the anonymous participants.

Duffy also tried the technique in his native Ireland. Tracing along a river that meanders through the city on its way to the ocean, Duffy found human DNA everywhere but the remote mountain stream where the river begins, far from civilization.

The scientists also collected air samples from a veterinary hospital room. They recovered DNA that matched that of 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 policymakers and scientific communities take consent and privacy issues seriously and balance them with the potential benefits of studying this wandering DNA. .

“Any time we make a technological breakthrough, there are beneficial things that technology can be used for and concerning things that technology can be used for. It’s no different here,” Duffy said. “These are issues that we are trying to raise early so that lawmakers and society have time to develop regulations.”