title: Plastic as a carrier of POPs to aquatic organisms: a model analysis.
abstract: It has been hypothesized that persistent organic pollutants (POPs) in microplastic may pose a risk to aquatic organisms. Here we develop and analyze a conceptual model that simulates the effects of plastic on bioaccumulation of POPs. The model accounts for dilution of exposure concentration by sorption of POPs to plastic (POP "dilution"), increased bioaccumulation by ingestion of plastic-containing POPs ("carrier"), and decreased bioaccumulation by ingestion of clean plastic ("cleaning"). The model is parametrized for the lugworm Arenicola marina and evaluated against recently published bioaccumulation data for this species from laboratory bioassays with polystyrene microplastic. Further scenarios include polyethylene microplastic, nanosized plastic, and open marine systems. Model analysis shows that plastic with low affinity for POPs such as polystyrene will have a marginal decreasing effect on bioaccumulation, governed by dilution. For stronger sorbents such as polyethylene, the dilution, carrier, and cleaning mechanism are more substantial. In closed laboratory bioassay systems, dilution and cleaning dominate, leading to decreased bioaccumulation. Also in open marine systems a decrease is predicted due to a cleaning mechanism that counteracts biomagnification. However, the differences are considered too small to be relevant from a risk assessment perspective.
authors.affiliation: Aquatic Ecology and Water Quality Management Group, Department of Environmental Sciences, Wageningen University , P.O. Box 47, 6700 AA Wageningen, The Netherlands. bart.koelmans@wur.nl
authors.forename: Albert A
authors.initials: AA
authors.lastname: Koelmans
authors.forename: Ellen
authors.initials: E
authors.lastname: Besseling
authors.forename: Anna
authors.initials: A
authors.lastname: Wegner
authors.forename: Edwin M
authors.initials: EM
authors.lastname: Foekema
mesh_terms: D000818:Animals; D059001:Aquatic Organisms / Q000187:drug effects*; D008962:Models, Theoretical; D009930:Organic Chemicals / Q000633:toxicity*; D010969:Plastics
chemical_list: D009930:Organic Chemicals; D010969:Plastics