What is bioaccumulation in organisms exposed to contaminated plastics?

In the context of environmental science, bioaccumulation refers to the process by which an organism absorbs and retains contaminants—such as those associated with plastic pollution—in its tissues over time because it cannot break them down or excrete them quickly enough.12

When organisms are exposed to contaminated plastics, bioaccumulation occurs through several mechanisms:

• Leaching and Ingestion: Plastics often contain chemical additives like phthalates, bisphenol A (BPA), and polybrominated diphenyl ethers (PBDEs). These chemicals can leach into the environment or be released directly into an organism's body upon ingestion.34
• Concentration of Pollutants: Plastics can act as vectors, concentrating other environmental pollutants (such as PCBs) from the surrounding water up to a million times their ambient levels. When animals ingest these plastics, they are exposed to these concentrated toxins.2
• Trophic Transfer: As contaminated prey are consumed by predators, these substances can undergo biomagnification, where the concentration of the contaminant increases at successively higher trophic levels in the food chain.512

Because these substances are often fat-soluble and resistant to degradation, they persist in the fatty tissues and organs of living organisms, posing long-term risks such as endocrine disruption, reproductive toxicity, and genetic damage.5314