Trophic transfer of microplastics and associated contaminants in marine food chains, and implications for human health

Abstract

Many marine organisms from minute plankton to whales have been shown to ingest plastic particles. In addition to consumption of plastic particles that are being confused with food items, plastic-seawater-organism interactions contribute to processes that alter the properties and transport of plastic particles and thereby facilitate ingestion of the plastic in a range of environmental compartments, along depth gradients and by different types of consumers. Biomagnification of plastic, i.e. the accumulation of plastic in a predator consuming many plastic-contaminated prey items, has rarely been shown under natural conditions, but experimental evidence exists for some species combinations that plastic can be ingested through consumption of prey that in turn ingested plastic itself. The health risks from ingested plastic originate from particle toxicity or the toxicity of associated chemicals that are released into the organism post-ingestion. Trophic transfer of plastics in marine food chains where humans represent the highest trophic level will also be discussed, demonstrating an urgent need to move toward a toxic-free circular plastic economy.