Human DNA Detected from Footprints and Breath

Scientists have been able to collect and analyze human DNA from footprints left on a beach, air breathed in a busy room and ocean water.

Researchers from the University of Florida said the DNA was of such high quality that the scientists could identify mutations associated with disease and determine the genetic ancestry of populations living nearby.

They could also match genetic information to individual participants who had volunteered to have their DNA recovered as part of the research published in the scientific journal Nature Ecology & Evolution on Monday.

The team at the University of Florida’s Whitney Laboratory for Marine Bioscience and Sea Turtle Hospital was using environmental DNA recovered from turtle tracks made on sand, when they noticed that they were also picking up human DNA from sand and in the ocean and rivers surrounding the lab, CNN reports.

They termed this information “human genetic bycatch” and decided to study the phenomenon in greater depth.

“All this very personal, ancestral and health-related data is freely available in the environment and is simply floating around in the air right now,” said David Duffy, a professor of wildlife disease genomics at the University of Florida.

Human DNA seeps into the environment through spit, skin, sweat and blood

Human DNA that has seeped into the environment through our spit, skin, sweat and blood could be used to help find missing persons, aid in forensic investigations to solve crimes, locate sites of archaeological importance, and for health monitoring through DNA found in waste water, the study noted.

However, the ability to capture human DNA from the environment could have a range of unintended consequences — both inadvertent and malicious, they added.

These included privacy breaches, location tracking, data harvesting, and genetic surveillance of individuals or groups. It could lead to ethical hurdles for the approval of wildlife studies.

Matthias Wienroth, a senior fellow studying social and ethical aspects of genetics in forensics, surveillance and human health at the University of Northumbria in the UK, said the scientists involved in the study had taken the “ethical aspects of their work seriously” and “identified some key issues that are likely to emerge with their findings.”

“It is important to preserve human autonomy, dignity and the right to self-determination over personal data. This is difficult if you can’t ask those whose DNA may be collected in the environment (for permission), because there’s probably no way to avoid losing DNA to the environment via skin, hair, and breath,” Wienroth, who was not involved in the research, told CNN.

He emphasized the need to develop and deploy foresight in genetics and genomics research: “A key issue is that such incidental eDNA findings may make their way into databases that can be compared with user data at other genetics databases, thus undermining informed consent and even customer confidentiality.”

They also retrieved DNA from footprints made in sand by four volunteers. With permission, they were able to sequence part of the participants’ genomes.

Next, the researchers took samples of air from a 280-square-foot room in an animal clinic where six people worked as they went about their normal daily routines. The team recovered DNA that matched the staff volunteers, animal patients and common animal viruses.

“These sequences recovered both the nuclear and mitochondrial regions of the human genome, which means that we can easily determine if a male or female (was) walking in the sun or (their) presence in a room depending on whether or not we sequenced the X or Y chromosome,” Duffy explained at a news briefing according to CNN.

“Using the mitochondrial genome, we were able to investigate the genetic ancestry of our samples.”

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