USGS-led study estimates lithium in groundwater

June 10, 2024

The first national estimates of naturally occurring lithium in groundwater that can be used for drinking water were recently published by the U.S. Geological Survey. The USGS-led study focuses on groundwater that supplies water to both public and private wells.

Ongoing research by health organizations has linked the low-level occurrence of natural lithium in drinking water to positive human-health outcomes such as reduced suicide mortality and other mental-health benefits in addition to potential negative outcomes such as autism and thyroid hormone levels. There are limited data, however, on where and at what concentrations lithium occurs in drinking water, or on what levels can lead to different health impacts.

“Lithium in well water has not been commonly monitored or measured in the United States in the past, and these new estimates and maps help fill the gap in that lack of information,” said Melissa Lombard, USGS research hydrologist and lead author of this study. “Understanding the potential lithium concentrations in groundwater used for drinking water across the country enables health researchers to further investigate and better understand how human health can be impacted by lithium exposure.”

Health researchers can combine this USGS-led study’s findings with national health data to determine potential connections between low level lithium exposure and human health outcomes. This study can also help inform well owners, water utility organizations, and water management agencies.

Lithium in drinking water is not currently regulated in the U.S. The metal is included in the most recent U.S. Environmental Protection Agency list of unregulated contaminants to be monitored by public water systems.

The USGS-led study estimates that lithium occurs in groundwater at concentrations of 30 micrograms per liter or higher in public and private wells in much of the western and southwestern states, including Montana, Wyoming, North Dakota, South Dakota, Colorado, Utah, Nevada, Arizona, New Mexico, and Texas. While to a lesser extent, lithium at those concentrations is also estimated in groundwater in the eastern and northeastern states.

This research focused on lithium occurrence due to natural processes, as the metal is present in certain minerals and can dissolve in groundwater. Naturally occurring lithium in groundwater is found at much lower concentrations compared to lithium used in pharmaceuticals to treat bipolar disorder and depression.

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