Artificial DNA in hydrology

The use of artificial DNA (artDNA) in hydrological applications is becoming increasingly popular, either in dissolved form (dissolved artDNA) or encapsulated and protected by a layer (encDNA). DNA can be detected even at low concentrations and offers the ability to create numerous uniquely identifiable DNA labels, making it ideal for a wide range of multi‐tracer applications. A literature review revealed that in streams, the breakthrough curve of artDNA is visually similar to that of a conservative tracer in terms of time to rise, time to peak, and dispersion coefficient. In saturated porous or fractured media, the time of first arrivals and time to peak of artDNA are usually earlier than that of a conservative tracer, indicating size exclusion of both dissolved artDNA and encDNA. Transport in subsurface media can be described by one‐site or two‐site kinetic attachment. The recovery of artDNA in environmental systems is always less than 100% due to adsorption and decay. Although the processes responsible for both are known, yet they cannot be quantified or predicted in mass balance approaches. Despite these limitations, artDNA can be used in various hydrological applications in environmental studies and engineering. Finally, attention should focus on the use of rapid detection of DNA tracers in the field, on upscaling of DNA production, and on increasing the efficiency of the DNA encapsulation process.