Columbia University Study Finds Lithium in Tap Water Exceeds Health Screening Levels in Western U.S. Tribal Communities

04 Aug Columbia University Study Finds Lithium in Tap Water Exceeds Health Screening Levels in Western U.S. Tribal Communities

Ellen Bannon

MedicalResearch.com: What is the background for this study? What are the main findings?

Ms. Bannon: Lithium is an increasingly important element thanks to its use in rechargeable batteries and the green energy transition. However, we know relatively little about how people are exposed to lithium in their everyday lives. In many areas of the United States, lithium is present in groundwater and drinking water due to natural weathering processes, but few studies have quantified human exposure to lithium. Our study addresses this gap by measuring lithium in household tap water and urine samples from participants in the Strong Heart Family Study across Tribal communities in Arizona, Oklahoma, North Dakota, and South Dakota. This approach parallels earlier work examining other naturally occurring groundwater contaminants — a framework explored in this MedicalResearch.com overview of how naturally occurring contaminants in drinking water affect human health even at low exposure levels.

Our main findings were threefold. First, household drinking water samples frequently exceeded the United States Geological Survey health-based screening level of 10 µg/L, with 100% and 93% of samples exceeding the screening level in Arizona and North Dakota/South Dakota, respectively. Both water and urine lithium levels were highest in Arizona and lowest in Oklahoma. Second, household drinking water is an important contributor to internal lithium exposure — water lithium concentrations were significantly associated with urinary lithium levels and explained approximately 29% of variation in urinary lithium. Finally, urinary lithium levels remained stable between our urine sampling periods (2006–2009 and 2022–2024), suggesting that environmental lithium exposure has remained persistent over time.

MedicalResearch.com: Is lithium found naturally in soil or water, or were other sources identified?

Ms. Bannon: Lithium is a naturally occurring element found in rocks, soil, and water. Generally, lithium is released from lithium-bearing rocks and minerals through weathering and water-rock interaction. Once dissolved into groundwater, it will persist in ion form and eventually enter drinking water supplies. Unlike many other drinking water contaminants, lithium is difficult to remove with standard drinking water treatment technologies — only reverse osmosis consistently removes lithium ions from water.

Our study focused on household drinking water, but it is likely that other exposures contribute to internal lithium exposure. Secondary water sources like bottled water or tap water from school, work, and community centers contribute to exposure. Diet and atmospheric deposition may also play a role. Additional research is needed to understand the potential pathways and quantify their roles in exposure.

MedicalResearch.com: What are the implications of increased human exposure to lithium?

Ms. Bannon: The health implications of long-term environmental lithium exposure remain uncertain. At therapeutic doses (600–1200 mg/day), lithium is used to treat bipolar disorder, and long-term adverse effects on renal and endocrine systems have been documented. These doses are several orders of magnitude higher than typical environmental exposures observed through drinking water. Epidemiologic studies of environmental lithium concentrations have reported mixed findings, with some evidence linking lithium in drinking water to thyroid dysfunction, impaired fetal development, and altered reproductive outcomes, while other studies have suggested potential benefits, including lower suicide rates and reduced risks of neuropsychiatric and neurodegenerative outcomes.

At this stage, our work was not evaluating health effects. Rather, we provide important evidence about where and how people are being exposed over time. Understanding exposure is a critical first step before researchers can determine whether environmental lithium has beneficial, harmful, or neutral effects on human health.

MedicalResearch.com: What should readers take away from your report?

Ms. Bannon: The main message is that naturally occurring lithium in household drinking water is an important source of human exposure in some communities in the western United States. We also found that urinary lithium is a useful biomarker of long-term environmental exposure because levels remained relatively stable over many years and closely reflected household drinking water concentrations. These findings provide an important foundation for future studies examining the potential health effects of environmental lithium exposure.

MedicalResearch.com: What recommendations do you have for future research as a result of this study?

Ms. Bannon: Our findings highlight several priorities for future research. First, we need studies that evaluate whether long-term environmental lithium exposure is associated with health outcomes. Research related to lithium’s primary target organs, including the kidney, thyroid, and brain, should be of particular interest. Second, researchers should investigate additional exposure sources beyond household tap water, including diet, bottled water, and occupational or environmental exposures. Finally, expanding environmental monitoring and biomonitoring to other regions will help us better understand how lithium exposure varies geographically and identify populations that may experience higher exposure levels.

MedicalResearch.com: Is there anything else you would like to add? Any disclosures?

Ms. Bannon: This work would not have been possible without the longstanding partnership between the Strong Heart Study, the Strong Heart Family Study, and the participating Tribal communities. We are grateful to the participants whose involvement makes this research possible.

Disclosures: The authors report no competing financial interests. Funding for the Strong Heart Study is supported by grants from the National Heart, Lung, and Blood Institute, the National Institute of Environmental Health Sciences, the National Institute of Diabetes and Digestive and Kidney Disease, and the National Institute on Minority Health and Health Disparities.

Citation:
Bannon EB, Lieberman-Cribbin W, Basu A, et al. Lithium exposure in areas of the Western United States: Water and urinary levels in the Strong Heart Family Study. J Expo Sci Environ Epidemiol. 2026. https://doi.org/10.1038/s41370-026-00947-7

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Last Updated on August 4, 2026 by Marie Benz MD FAAD