Read the full article by Saima May Sidik (Eos).
“When representatives of 197 countries ratified the Montreal Protocol to phase out ozone-depleting substances in 1987, they probably didn’t anticipate creating a new method for estimating the age of groundwater.
But the Montreal Protocol paved the way for a chemical called trifluoroacetic acid, or TFA, to become widespread in the atmosphere, and therefore in rainwater. Because the concentration of TFA has increased steadily since 1987, it’s a helpful tool for gaining a rough idea of how recently an aquifer has been recharged—which is what is meant by ‘groundwater age.’
Using TFA as a quick and easy tracer is one of several research techniques that rely on the mass amounts of anthropogenic material that enter the environment every moment of every day. Scientists are using pollution to study processes both small-scale and worldwide, from the history of a single bird’s nest to the history of humans on this planet.”…