A new systematic review and meta-analysis, published on 30 July 2025 in Frontiers in Medicine, provides strong evidence that environmental cadmium exposure raises the risk of developing kidney stones. The findings are based on 17 studies covering more than 159,000 individuals across Asia, Europe and the United States.
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The analysis found that people with the highest levels of cadmium exposure had a 19% greater risk of kidney stones compared to those with the lowest exposure. A subgroup analysis revealed that cadmium measured in blood was linked to an even higher relative risk of 49%. Urinary cadmium exposure also showed a clear dose–response relationship: each 1 μg/L increase in urinary cadmium was associated with a 7% increase in kidney stone risk.
The association was strongest in cadmium-contaminated regions, where elevated exposure correlated with higher disease rates. By contrast, no significant link was found in populations from non-contaminated areas. The researchers also observed differences across populations: non-Asian cohorts showed a stronger correlation than Asian cohorts, while men appeared less affected than women or mixed study groups.
Cadmium is a toxic heavy metal found in industrial emissions, contaminated soils, fertilizers and certain foods. It accumulates in the kidneys over time, impairing their function and contributing to calcium imbalances that promote stone formation. Previous studies suggested this link, but results were inconsistent. By pooling global data, this analysis provides some of the most comprehensive confirmation to date.
Despite these findings, limitations remain. High heterogeneity between studies and limited data on dietary exposure make it difficult to draw firm conclusions in all cases. The authors call for further prospective cohort studies and stricter monitoring of cadmium levels in the environment and food supply.
The study underscores that reducing environmental cadmium exposure could lower the prevalence of kidney stones, a condition affecting 10–12% of men and 5–6% of women worldwide. As kidney stones are both painful for individuals and costly for healthcare systems, preventive action could yield significant public health benefits.
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