Excretion is the final step in the toxicokinetic process, where toxicants and their metabolites are eliminated from the body. The primary routes of excretion include the urinary tract, the gastrointestinal tract, and the respiratory system. The kidneys play a vital role in filtering water-soluble toxicants from the blood, while fat-soluble toxicants may be excreted via bile into the feces. Inhaled toxicants are often exhaled through the lungs.
