Persistent, bioaccumulative, and toxic (PBT) chemicals are a class of chemicals that resist degradation and persist in the environment for extensive periods. As a result of their persistence, when these chemicals are consumed, they bioaccumulate in the fat tissues, bones, and brain of organisms. Lead (Pb) is a PBT metal with the ability to bind irreversibly to neurons and to mimic natural minerals like calcium and zinc. The aim of this review is to examine the unique properties of a PBT, like Pb, as well as the analytic methods of detecting and characterizing PBTs. This review offers sections that explore Pb's persistence in the environment, bioaccumulation in fish and birds, and toxic characteristics in the human body. It further examines how Pb's effects on transcription factors could explain the observed Pb lines in Pb-poisoned individuals. This review also evaluates the relationship between the properties of persistence and bioaccumulation as a means to determine whether or not they are interconnected, interdependent, or independent of one another.