Objectives

• Use artificial weathering in lab experiments combined with non-target chemical analysis and particle imaging to “fingerprint” weathered plastic particles
• Investigate how weathering processes of MPs influence their vertical distribution, trophic transfer and toxicity (by affecting size distribution, surface morphology, density, aggregation-flocculation behaviour and microbial biofilm communities)
• Investigate if the 3D spatial distribution from lab-scale column tests can be extrapolated to field data from the Stockholm Archipelago and Oslo Harbour (using sediment transport models parameterized for MPs)
• Assess toxic effects of weathered MPs by
  • toxicity tests using OECD guidelines adapted for ecotoxicological testing of MP particles
  • changes in biofilm communities
  • cell-based bioassays with MP leachates to identify modes-of-action and to quantify toxicity
• Develop new tools to incorporate MP weathering into risk assessment of marine MP pollution