New Biomarker Identifies Uranium Accumulation in Kidneys and Potential Damage

A groundbreaking study conducted by researchers at Columbia University's Mailman School of Public Health has revealed that the isotopic composition of uranium can serve as a reliable biomarker to assess its accumulation in human kidneys. This discovery is significant because uranium, which contaminates drinking water sources, can build up in the kidneys even at low exposure levels, posing a risk for kidney damage over time.

Uranium exposure from contaminated water is a recognized environmental health concern, especially in regions with natural deposits or legacy mining activities. The study demonstrates that the uranium isotopic signature in urine accurately reflects its presence in kidney tissues. This noninvasive detection method could enable early identification of uranium buildup, facilitating timely intervention before irreversible kidney damage occurs.

The research involved experiments with mice exposed to contaminated water for 7 to 14 days, revealing that uranium preferentially accumulates in the kidneys and bones, with distinct isotopic signatures. These findings suggest that monitoring uranium isotopes in urine offers a cost-effective, practical way to evaluate individual exposure levels, particularly in high-risk communities.

Anirban Basu, Ph.D., senior author of the study, emphasized the importance of this biomarker: "Uranium enters the body through drinking water and is filtered by the kidneys, where it can cause long-term harm. Urinary uranium isotopic analysis could be a sensitive tool for assessing kidney accumulation and assessing health risks."

The study highlights that nearly 66% of U.S. community water systems have detectable uranium levels, with some exceeding federal safety limits. Vulnerable populations, including those in the Great Plains and Colorado Plateau—areas with natural uranium deposits—are at increased risk. Given the chemical toxicity of uranium at low concentrations, understanding and detecting early kidney effects is vital.

Current measurement techniques do not precisely target kidney-specific accumulation, creating a gap in timely diagnosis and prevention. This research lays the groundwork for developing precision biomarkers to enable early detection and intervention, potentially reducing chronic kidney disease caused by environmental uranium exposure.

Future research aims to explore longer-term exposure effects and lower uranium doses to further validate this biomarker’s utility for environmental health surveillance.