Low-Level Environmental Cadmium Exposure and Its Effects on Renal and Bone Health in Brazilian Postmenopausal Women: A Cross-Sectional Study

Abstract

This study aimed to investigate the long-term effects of low-level, chronic exposure to cadmium (Cd) on renal and bone health. A cross-sectional study was conducted on postmenopausal women (n = 380) from Cascavel, Brazil, an agricultural region where the use of Cd-containing fertilizers may exacerbate environmental contamination. Demographic and clinical data were collected, and cumulative Cd exposure was assessed through urinary Cd (UCd) concentrations using inductively coupled plasma mass spectrometry (ICP-MS). Renal tubular function was evaluated by measuring urinary β2-microglobulin, and bone mineral density (BMD) at the lumbar spine, femoral neck, and total hip was assessed using dual-energy X-ray absorptiometry. Median UCd concentrations confirmed low exposure (0.30 µg/g creatinine; interquartile range: 0.15–0.55). Univariate analysis revealed a borderline association between higher UCd concentrations and lower BMD at the femoral neck across normal, osteopenic, and osteoporotic groups (p = 0.067). Multiple linear regression analysis showed that UCd was not independently associated with reduced BMD but was a significant predictor of renal tubular damage (p < 0.001). These findings underscore a pressing environmental and public health issue: even low levels of Cd exposure correlate with subclinical renal tubular dysfunction. Enhanced monitoring and stricter environmental regulations are critical to prevent long-term kidney damage and related health risks, especially in vulnerable populations.