Testing for Toxic Elements: A Focus on Arsenic, Cadmium, Lead, and Mercury

Toxic elements ("heavy metals") are common to the environment and are responsible for both intentional poisonings and unintentional exposures that can lead to adverse health effects and potentially death. Dangerous exposures can be prevented by recognizing and minimizing common sources of toxic elements in our diet, water, workplace, and homes. Laboratory testing is an important tool for detecting and managing toxic element exposure; several analytical methods are available. However, the clinical value of elemental testing is dependent upon collecting an appropriate specimen at an appropriate time, with consideration of many pre-analytical variables that can compromise testing. In this review, toxicokinetics and pre-analytical variables associated with toxic element testing are discussed, with emphasis on arsenic, cadmium, lead, and mercury.