Lithium is a metal found naturally in some water sources. It's used in batteries and medications. Industrial processes can increase lithium levels in drinking water.

Lithium enters water supplies through natural weathering of rocks and soil. While trace amounts are common, industrial activities can elevate concentrations. Scientists measure lithium using atomic absorption spectroscopy. Despite its use in mood-stabilizing medications, the health effects of lithium in drinking water remain debated. Currently, there's no federal regulation for lithium in public water systems. Some research suggests potential benefits from low-level exposure, but more studies are needed to confirm these findings.