ABSTRACT
Alterations in the circulating blood cell (erythrocyte or leukocyte) or platelet (thrombocyte) mass in animals or humans exposed to agents of environmental or therapeutic importance are a key consideration when assessing potential toxicity and hazard of the agent. Since an agent may directly or indirectly affect the circulating blood cell mass or production of blood cells, evaluations of the whole blood and the hematopoietic system (i.e., the bone marrow) are essential to understand agentinduced alterations in the erythron, leukon, or thrombon.
