title: Assessment of microplastic-sorbed contaminant bioavailability through analysis of biomarker gene expression in larval zebrafish.
abstract: Microplastics (MPs) are prevalent in marine ecosystems. Because toxicants (termed here "co-contaminants") can sorb to MPs, there is potential for MPs to alter co-contaminant bioavailability. Our objective was to demonstrate sorption of two co-contaminants with different physicochemistries [phenanthrene (Phe), log10Kow=4.57; and 17α-ethinylestradiol (EE2), log10Kow=3.67] to MPs; and assess whether co-contaminant bioavailability was increased after MP settlement. Bioavailability was indicated by gene expression in larval zebrafish. Both Phe and EE2 sorbed to MPs, which reduced bioavailability by a maximum of 33% and 48% respectively. Sorption occurred, but was not consistent with predictions based on co-contaminant physicochemistry (Phe having higher log10Kowwas expected to have higher sorption). Contaminated MPs settled to the bottom of the exposures did not lead to increased bioavailability of Phe or EE2. Phe was 48% more bioavailable than predicted by a linear sorption model, organism-based measurements therefore contribute unique insight into MP co-contaminant bioavailability.
authors.affiliation: School of Marine Science and Engineering, Marine Biology and Ecology Research Centre, University of Plymouth, Plymouth PL4 8AA, UK; British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, Cambridge, CB3 0ET, UK; Institute of Life and Earth Sciences, School of Energy, Geoscience, Infrastructure and Society, Heriot-Watt University, Edinburgh EH14 4AS, UK. Electronic address: viceig15@bas.ac.uk.
authors.forename: Victoria A
authors.initials: VA
authors.lastname: Sleight
authors.affiliation: School of Marine Science and Engineering, Marine Biology and Ecology Research Centre, University of Plymouth, Plymouth PL4 8AA, UK; Petroleum and Environmental Geochemistry Group, School of Geography Earth and Environmental Sciences, University of Plymouth, Drake Circus, Plymouth, Devon PL4 8AA, UK; School of Earth & Environmental Sciences, University of Portsmouth, Burnaby Road, Portsmouth PO1 3QL, UK.
authors.forename: Adil
authors.initials: A
authors.lastname: Bakir
authors.affiliation: School of Marine Science and Engineering, Marine Biology and Ecology Research Centre, University of Plymouth, Plymouth PL4 8AA, UK.
authors.forename: Richard C
authors.initials: RC
authors.lastname: Thompson
authors.affiliation: School of Marine Science and Engineering, Marine Biology and Ecology Research Centre, University of Plymouth, Plymouth PL4 8AA, UK; British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, Cambridge, CB3 0ET, UK; Center for Environmental Biotechnology, University of Tennessee, Knoxville, TN 37996, USA; Department of Forestry, Wildlife and Fisheries, University of Tennessee, Knoxville, TN 37996, USA.
authors.forename: Theodore B
authors.initials: TB
authors.lastname: Henry
mesh_terms: D000818:Animals; D001682:Biological Availability; D015415:Biomarkers / Q000378:metabolism; D004997:Ethinyl Estradiol / Q000378:metabolism; D015870:Gene Expression; D007814:Larva / Q000235:genetics / Q000378:metabolism; D010616:Phenanthrenes / Q000378:metabolism; D010969:Plastics / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000378:metabolism*; D015027:Zebrafish / Q000235:genetics* / Q000378:metabolism
chemical_list: D015415:Biomarkers; D010616:Phenanthrenes; D010969:Plastics; D014874:Water Pollutants, Chemical; D004997:Ethinyl Estradiol; C031181:phenanthrene
keywords: 17α-ethinylestradiol; Bioavailability; Danio rerio; Microplastics; Phenanthrene; Sorption