DNA fragments in air, soil and water could be used in the investigation of crime and warn of biosecurity threats

Genetic material in water, soils or the air could be used in the investigation of crime or warn of imminent biosecurity threats, according to a report by the Royal Society, the UK’s national academy of sciences.

The Environmental DNA explainer for UK policy makers explores potential applications for monitoring environmental DNA (eDNA) contained in cellular material shed by living organisms in skin, saliva, or other sources.

It sets out a number of areas where investment, supportive regulation and a coordinated approach to collecting, analysing and storing eDNA data could benefit a range of sectors, from agriculture to forensic science.

The report also highlights a number of ethical, legal, data and infrastructure challenges that must be resolved to realise these opportunities and mitigate the risk of harm or over interpretation. This includes the risk of human eDNA genetic “bycatch” where DNA could be captured from the environment without consent.

While eDNA techniques are established in biodiversity monitoring, the report highlights a number of other emerging applications, including:

• Environmental quality and pollution monitoring: eDNA can be used to assess microbial contaminants in water, or species diversity in polluted environments
• Biosecurity and defence: Water sampling or air capture eDNA technologies can detect crop pests, invasive species, and potential bioterror threats, offering a preventative approach to biosecurity
• Crime scene investigation and forensic science: Plant and animal DNA is already being used to help trace the origin of illegal wildlife products. In future, eDNA, within dust and soil could be used to connect individuals to crime scenes or search for missing persons
• Public Health: eDNA analysis of wastewater has already been instrumental in tracking the spread of diseases such as COVID-19, polio, and monkeypox, enabling timely public health interventions

With a strong research base and a number of eDNA-specific companies spun out of its universities, the report highlights the UK is well placed to benefit from eDNA techniques being adopted across a range of expanding markets.

Its extensive natural history collections, and initiatives like the Wellcome Sanger Darwin Tree of Life project (which aims to sequence genomes of all native UK species) could also make the UK a leader in the genetic reference libraries needed to match eDNA fragments to species.

Crucially, as eDNA technologies advance, it is vital that sector regulators and policymakers keep up with their evolving uses and the resulting ethical and legal implications that may emerge.

Professor Sir Ian Boyd, Bishop Wardlaw Professor, University of St. Andrews and a member of the report’s review group, said:

“The rapid expansion of the field of eDNA is exciting and the potential applications are vast.

“Investing in the research infrastructure and regulatory frameworks that can adapt to these emerging uses, and their ethical or commercial implications, is vital for the UK is well placed to capitalise on opportunities whether that’s food, environmental management, public health or defence.”

Professor Niamh Nic Daeid, Professor of Forensic Science and Director of the Leverhulme Research Centre for Forensic Science at the University of Dundee and a member of the report’s working group, said:

“The interpretation of forensic evidence can have serious and life changing consequences. Forensic science research will be needed to validate eDNA techniques alongside their development so that they are fit for purpose for implementation into the criminal justice system.

“We still have a lot to learn about how eDNA can be transferred given different activities; how long it persists on different surfaces, and the background prevalence of different species’ eDNA in the environment.

“Understanding this will be critical to evaluating eDNA findings and what they may contribute to an investigation of an alleged incident and presentation of any evidence in the courts.”