Microplastics in sediments on the Norwegian Continental Shelf II: Identification through FT-IR analysis

During the regional environmental sediment monitoring on the Norwegian Continental Shelf on behalf of the oil & gas industry in 2017, 35 sediment samples from a large geographical area were sampled, covering the central North Sea, northern North Sea and the Barents Sea.

The sediment samples were analyzed at the Norwegian Geotechnical Institute (NGI) for potential maximum microplastic abundance (with a particle size ranging from 45 μm to 5 mm) as described in DNV GL (2018).

This earlier analysis was based on the assumption that all particles with a density less than the density separation fluid of 1.53 g/mL, having a size range between 45 μm and 5 mm, and resilience to an organic matter digestion process, potentially could be microplastics.

As mentioned in the report, this conservative estimate could also include other materials such as soot, char, porous glass and ceramics, as well as resistant organic matter with regards to the organic matter digestion process.

NB! Miljødirektoratets forvaltning skal være basert på vitenskapelig kunnskap. Vi har som mål å holde oss faglig oppdatert og bidra til et felles og helhetlig kunnskapsgrunnlag som har legitimitet. Vi ønsker dermed å presisere at denne rapporten beskriver kunnskapsstatus på publiseringstidspunktet.

Mikroplast er et komplekst tema hvor ny kunnskap produseres hyppig. Det er i ettertid stilt spørsmål om "paint" skal være blant plastkategoriene i rapporten eller om "epoxide resin", "phenoxy resin" og / eller "oxy-resins er bedre egnet. Det er i tillegg usikkert om alle partikler beskrevet som malingrester i rapporten, egentlig stammer fra maling.