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Kinetics of POP sorption and plastic additive release to a variety of polymers under Arctic conditions

Herzke, Dorte; Sakaguchi-Söder, Kaori; Sempere, Richard; Fauvelle, Vincent; Booth, Andy

Publication details

Event: MICRO 2018 Fate and Impact of Microplastics: Knowledge, Actions and Solutions (Lanzarote)

Date: November 19th 2018 – November 23rd 2018

The PLASTOX project investigates the ingestion, food-web transfer, and ecotoxicological impact of microplastics (MPs), together with the persistent organic pollutants (POPs), metals and plastic additive chemicals associated with them, on key European marine species and ecosystems. PLASTOX combines field-based observations, laboratory tests and manipulative field experiments to study the ecological effects of MPs.

As part of a long-term field experiment conducted at marine locations across Europe (Mediterranean to Arctic), a range of different virgin polymer pellets, post-use polymers (LDPE, PP, PS and PET), as well as marine litter-derived microplastic particles, were deployed underwater for up to 12 months in the small boat harbour of Tromsø, Northern Norway. The deployment device consisted of an empty stainless steel SPMD canister, with the various plastic types placed in reusable, empty 'teabags' made of PP, placed separately in nylon netting. Sampling was conducted 1 week, 1 month, 3 months, 6 months and 12 months after deployment. Hydrophobic persistent organic pollutants such as PAHs, PCBs, DDTs, PBDEs and pesticides that had become associated with the plastic were measured and their adsorption kinetics in seawater under Arctic conditions established. Samples were extracted using ultrasound and non-polar solvents, followed by GPC and SPE clean up prior to chemical analysis and quantification by GC/MS/MS and GC/qMS. The release kinetics of common plastic additives, including phthalates, organophosphate esters, bisphenols and perfluorinated chemicals, were estimated from four types of post-industrial virgin pellets (LDPE, PS, PVC, PET) according to the same sampling protocol. Chemical analysis was performed using either GC/MS or LC-QTOF.

Results show that HCB and PCBs represented the dominant pollutant classes adsorbing to all of the different polymer types, but at concentrations that are more than 10-times lower than those previously reported. However, equilibrium between pollutants and the polymers was not reached during the deployment period, indicating that Arctic conditions may result in different sorption kinetics than observed in temperate regions.