What term describes the buildup of a contaminant within an organism over time?

• A. Biomagnification
• B. Bioaccumulation
• C. Biodegradation
• D. Biotransformation

Answer: (B)

Bioaccumulation describes the gradual buildup of a contaminant in an individual organism over time, as ongoing uptake exceeds the rate at which the substance is eliminated. This happens when persistent, often fat-soluble pollutants are continually absorbed from water, air, or food and are stored in tissues, causing concentration to rise inside the organism over time. This focus on accumulation within a single organism is what sets it apart from related ideas.

Biomagnification, by contrast, refers to higher concentrations in organisms at higher spots in the food chain, driven by consuming prey that already contain the contaminant. Biodegradation is the breakdown of pollutants by biological processes, reducing their presence. Biotransformation is the metabolic modification of a compound inside an organism, often to prepare it for excretion, which can change the substance but isn’t about net buildup.