Figure 2.

Potential stages in the development of toxicity following chemical exposure. Toxicity involves the delivery of the toxicant to the target tissue where an interaction with its target molecule(s) may result in cellular dysfunction, which is primary mediated by aberrant cell signaling and inadequate cell maintenance. The process may involve the toxicant itself or its metabolism product, which could be more reactive than the parent compound. Damaged cells could die off or attempt to repair, recover, and restore homeostasis. Cells that attempt to repair and recover tend to undergo apoptosis if repair and recovery fails. The surviving damaged cells could trigger the development of an adverse outcome, including carcinogenesis.