ABSTRACT
This chapter is concerned with substances that enter the body and are distributed by the blood stream. Once a toxicant is in the body, the concerns are how long it stays, what organs it damages, and how it is removed. The toxicologist discusses the rates of various events through the body under the general heading toxicokinetics. People who work in toxicokinetics sometimes refer to passage through the body by absorption, distribution, metabolism, and elimination. The chief pathway for removal of toxicants from the body is to transfer them in the kidneys from the blood into the urine. Toxicants enter the blood circulation to be distributed throughout the body through the GI tract, skin, and lungs. One of the studies performed on toxicants is the determination of their half-life in the body. By half-life we mean the length of time required when a known amount of a compound is taken into the body for half of it to be removed.
