プラスチックが媒介する有害化学物質の海洋生物ヘの曝露と移行

摘要

Plastics often contain hazardous additives such as polybrominated diphenyl ethers (PBDEs) and nonylphenols. Hydrophobic additives are carried in mm-size plastics, though some are leached to seawater during fragmentation and transport in marine environment. Plastics in marine environments sorb and accumulate persistent organic pollutants (POPs) form the surrounding seawater. Sporadically high concentrations of POPs are often observed in mm-size plastics at remote locations probably due to combination of rapid transport of the floating plastics and slow sorption/desorption of POPs to/from mm-size plastics. Transfer of POPs from ingested mm-size plastics to biological tissue of higher-trophic-level organisms was demonstrated by a field feeding experiment and tissue and plastic analyses for PBDEs and PCBs. Transfer of POPs from μm-size plastics to lower-trophic-level organisms has been suggested by some laboratory ingestion experiments. However, magnitude of these transfers has not been reveled and should be focused on the future studies.