Water that has been stored in the Earth’s crust for thousands of years can still be contaminated by modern chemicals, a new analysis suggests. Researchers analyzed groundwater from over 6,000 wells around the world, and concluded that old groundwater accounts for the majority of groundwater from wells deeper than 250 meters. But the team made a troubling discovery: some of the fossil groundwater contained traces of the radioactive hydrogen isotope tritium, which was spread as a result of nuclear testing in the 1950s. These findings suggest that some of the “younger” groundwater got mixed in with the fossil waters, contaminating them. This discovery carries implications for the effects of human activity on a vital resource that long predates humans on Earth.
Authors:
Scott Jasechko, Debra Perrone, Kevin M. Befus, M. Bayani Cardenas, Grant Ferguson, Tom Gleeson, Elco Luijendijk, Jeffrey J. McDonnell, Richard G. Taylor, Yoshihide Wada & James W. Kirchner
Corresponding author:
Scott Jasechko, University of Calgary, Email: sjasechk@ucalgary.ca
Original paper published in Nature on April 25, 2017.
