Boon Or Ethical Concern? Human DNA Can Now Be Extracted From Thin Air And Water

DNA which can be found in the environment is known as environmental DNA (eDNA). Now, human genetic information can be extracted from thin air, a new study says.

Pathogen surveillance, biodiversity monitoring, endangered and invasive species detection, and population genetics will become more advanced if scientists broadly adopt eDNA analysis, the study said. 

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Earlier, human DNA could be extracted only from blood samples, skin cells, hair strands, or some other body parts. But now, genetic information can be extracted from thin air. Surprising, isn't it? Hereditary information can also be obtained from a person's breath sand, and a vial of water, according to a new study led by University of Florida. 

DNA can be found on the beach, in the ocean, along riverways, and many other places, because humans spit, shed and flush their genetic material into countless regions, the study, published May 15 in the journal Nature Ecology & Evolution, said. 

According to a statement released by the University of Florida, one can find human DNA nearly everywhere, except for isolated islands and remote mountaintops. 

Environmental DNA and human genetic bycatch

DNA which can be found in the environment is known as environmental DNA (eDNA). 

According to the study, human eDNA applications remain underutilised and under considered despite the field of eDNA advancing rapidly. Pathogen surveillance, biodiversity monitoring, endangered and invasive species detection, and population genetics will become more advanced if scientists broadly adopt eDNA analysis, the study said. 

The authors noted in the study that deep-sequencing-based eDNA approaches capture human genetic information just as readily as that from the intended target species. This phenomenon of capturing human genetic information using eDNA approaches is known as human genetic bycatch (HGB), the study said. 

Where can eDNA be obtained from?

One can intentionally recover high-quality eDNA from environmental substrates such as water, sand and air. This holds promise for beneficial medical, forensic and environmental applications. 

Ethical concerns associated with eDNA

While eDNA is surely a boon for the scientific community, it also raises several ethical concerns and dilemmas. 

According to the authors, the ethical concerns include consent, privacy, surveillance, and data ownership. Therefore, further consideration and novel regulation are required. 

In the study, the researchers have presented evidence that human eDNA is readily detectable from 'wildlife' environmental samples as human genetic bycatch, demonstrated that identifiable human DNA can be intentionally recovered through environmental sampling, and discussed the ethical implications of these findings. 

The eDNA obtained by the researchers was of such high quality that they were able to identify mutations associated with disease, and determine the genetic ancestry of nearby populations, the statement said. 

Quoting David Duffy, the researchers who led the study, the statement said ethically handled environmental DNA samples could benefit medicine, environmental science, archaeology, and criminal forensics.

He explained that using eDNA, researchers can track cancer mutations from wastewater or spot undiscovered archaeological sites by checking for hidden human DNA, and detectives can identify suspects from the DNA floating in the air of a crime scene. 

However, scientists must carefully handle this level of personal information, and grapple with the ethical dilemmas inherent in accidentally or intentionally sweeping up human genetic information from the environment, the statement said. 

Since eDNA can help identify individuals, ethical constraints are necessary for this kind of approach, according to the researchers. They conducted the study with approval from the institutional review board of the University of Florida, which ensures that scientists adhere to ethical guidelines during research studies. 

Where did the researchers obtain eDNA from?

According to the statement, Duffy's team has used eDNA to study endangered sea turtles and the viral cancers they are susceptible to. The team collected useful DNA out of turtle tracks in the sand. 

The researchers also found quality human DNA in the ocean and rivers surrounding the Whitney Laboratory at the University of Florida, both near town and far from human settlements, and also in the sand from isolated beaches. However, they found no DNA in a remote island never visited by humans.

Human DNA was also found in air samples from a veterinary hospital, and this eDNA matched the genetic material of the staff, the animal patient, and common animal viruses, the statement said. 

Potential malicious applications of eDNA

The authors noted in the study, that some potential malicious applications of the capture of human genomic eDNA data include genome harvesting, covert accumulation of human genetic data for malicious or commercial purposes, genetic surveillance, and bio-piracy of human genetic data from populations and countries. 

The authors explained that genome harvesting refers to the ability to illegally or unethically harvest human genomic data from local populations or ethnic groups without their knowledge or consent. 

Genetic surveillance can be conducted for individual tracking, similar to forensics and wildlife applications, or for unethical tracking and locating ethnic groups. 

There is also a potential for involuntary genetic surveillance from investigative applications. For instance, a bystander may shed genetic information, which detectives and scientists may recover. 

The bio-piracy of human genetic data from populations and countries is similar to genetic bio-piracy of flora and fauna. 

How eDNA can benefit humanity and wildlife

The potential beneficial applications of human eDNA as the nascent field matures include the discovery of novel human genetic variation, the ability to conduct population-based disease risk susceptibility studies, non-invasive monitoring of host genetic, health monitoring, finding missing persons, forensic and criminal investigation, and archaeological surveys, among others. 

According to the study, discovering novel human genetic variation can help redress the historical imbalance in human genomic databases which do not span the range of human diversity. 

Researchers will be able to carry out population-based disease risk susceptibility studies, by analysing wastewater or air samples, and conducting active pathogen surveillance. 

Scientists can also conduct studies of host genetics through non-invasive monitoring. Studies on pathogen load and the transmission of these organisms can also be conducted. 

According to the study, human eDNA can be used as a new tool in continual health monitoring and continual personalised medicine biomarker monitoring, which means that biomarkers required for personalised medicines can be monitored with the help of eDNA. These techniques will facilitate chronic disease management initiatives, especially somatic mutations, which arise spontaneously and can lead to life-threatening diseases such as cancer. 

The study said that eDNA can enable sensitive quantification and source identification of human effluent entering and polluting waterways and aquifers. 

Using air eDNA, detectives and scientists can solve crimes during forensic and criminal investigations. 

Missing persons or deceased remains, especially in remote locations, can be recovered with the help of human eDNA. 

Scientists can discover sites of archaeological importance, such as sacrificial sites with cryptic human remains, with the help of eDNA. 

The authors said that eDNA can serve as a roadmap for future wildlife studies, because these approaches, along with existing rich human genomic databases, will be highly informative and help obtain more details for wildlife eDNA population genomics.