Chronic toxicity is produced by prolonged exposure to toxicants or poisons for 3 months or longer; prolonged exposure may lead to what adaptation?

• A. Tolerance due to metabolic detoxification
• B. Immediate death
• C. No effect
• D. Hyperactivity

Answer: (A)

Chronic exposure can trigger the body to bolster its defenses by increasing detoxification capacity. When a toxicant is encountered over a long period, liver enzymes that metabolize and detoxify compounds—such as certain cytochrome P450 enzymes—can be induced. This heightened metabolic activity speeds up the breakdown and clearance of the toxin, reducing its concentration at target sites and diminishing the toxic effect. This adaptive change is known as tolerance due to metabolic detoxification.

Immediate death would be an acute, not adaptive, outcome. No effect isn’t an actual adaptive process, and hyperactivity isn’t a typical response to prolonged detoxification.