Renal and Neurologic Effects of Cadmium, Lead, Mercury, and Arsenic in Children: Evidence of Early Effects and Multiple Interactions at Environmental Exposure Levels

TLDR

Lead, cadmium, mercury, and arsenic are common environmental pollutants in industrialized countries, but their combined impact on children's health is little known. The study examined the effects of these metals on renal and dopaminergic systems in over 800 children across Europe. Participants were recruited near historical nonferrous smelters in France, the Czech Republic, and Poland, and provided blood and urine samples to measure metal concentrations and sensitive biomarkers. Higher blood lead levels were linked to early renal hyperfiltration, while cadmium and mercury exposure affected urinary renal biomarkers, and all four metals altered dopaminergic markers, indicating subtle, threshold‑free effects on children’s renal and dopaminergic systems.

Abstract

Lead, cadmium, mercury, and arsenic are common environmental pollutants in industrialized countries, but their combined impact on children's health is little known. We studied their effects on two main targets, the renal and dopaminergic systems, in > 800 children during a cross-sectional European survey. Control and exposed children were recruited from those living around historical nonferrous smelters in France, the Czech Republic, and Poland. Children provided blood and urine samples for the determination of the metals and sensitive renal or neurologic biomarkers. Serum concentrations of creatinine, cystatin C, and β2-microglobulin were negatively correlated with blood lead levels (PbB), suggesting an early renal hyperfiltration that averaged 7% in the upper quartile of PbB levels (> 55 μg/L; mean, 78.4 μg/L). The urinary excretion of retinol-binding protein, Clara cell protein, and N-acetyl-β-d-glucosaminidase was associated mainly with cadmium levels in blood or urine and with urinary mercury. All four metals influenced the dopaminergic markers serum prolactin and urinary homovanillic acid, with complex interactions brought to light. Heavy metals polluting the environment can cause subtle effects on children's renal and dopaminergic systems without clear evidence of a threshold, which reinforces the need to control and regulate potential sources of contamination by heavy metals.