Toxicology of Heavy Metals in Biological Matrices: A Paradigm Shift From Single-Analyte Measurement to Comprehensive Screening

Background The clinical diagnosis of heavy metal toxicity presents a formidable challenge, largely because of symptomatology, which is notoriously nonspecific and capable of mimicking a wide array of common medical conditions. The current diagnostic paradigm, which relies on measuring a single metal in response to specific clinical suspicion, is often inadequate. This approach fails to account for the complex, interconnected nature of the human metallome, in which the toxicity of 1 element is profoundly influenced by the status of others. Antagonistic and synergistic interactions between toxic and essential metals are fundamental to the pathophysiology of toxicity and are largely ignored in single-analyte testing. Methods: This narrative review argues for a paradigm shift from targeted measurements to comprehensive quantitative screening. Results: We delineated the diagnostic difficulties due to nonspecific symptoms and how existing clinical guidelines focus on single-element action levels. We then present an intricate web of metal–metal interactions that render the current approach insufficient. The cornerstone of this argument is the maturation of analytical technology. Inductively coupled plasma tandem mass spectrometry (ICP-MS/MS) has overcome the longstanding challenge of atomic and polyatomic interference in complex biological matrices owing to its high selectivity, enabling the development of robust, validated, and high-throughput multielement panels. Conclusions: By providing a holistic view of an individual's elemental profile, the metallomic footprint of their exposome, this approach offers a more complete and clinically relevant picture, capturing not only the toxicant but also the biological context in which it acts. We conclude that quantitative multielement screening is no longer a theoretical possibility but a practical necessity for clinical toxicology to enhance diagnostic accuracy and improve patient outcomes.