Comparisons between ingestion, rejection, and egestion of microbeads by burrowing clams, Meretrix meretrix and Paphia undulata: Implications for health risk of shellfish consumption.

Two burrowing clam species, namely Meretrix meretrix and Paphia undulata, were offered two sizes (small: 45-53 μm, and large: 106-125 μm) of fluorescent red polyethylene microbeads, and the ingestion (number of MPs in the body tissue and faeces) and rejection (number of MPs in pseudofaeces) of MPs investigated. Overall, MP beads ingested were 36 % more than those rejected. There was also a significant interaction between the size and fate of MPs.