Microplastics; the search for empirical evidence

Plastic in the form of very small particles, called ‘microplastic’, pollutes much of the marine environment. While estimations are high, empirical evidence are lacking. NIVA are working to fill these knowledge gaps.

Awareness of the environmental problems stemming from plastic pollution has increased lately. Plastic has been found in the stomachs of Norwegian cod and fulmars, and there is discussion about cosmetics, artificial grass, plastic bag fees and wear and tear of car tires. But the knowledge about the sources and effects of microplastics in the ocean is limited.

Not plastic

NIVA works hard to fill the knowledge gaps. When NRK Hordaland (The Norwegian Broadcasting Corporation) reported that Bjarne Fosse, while enjoying his meal of shrimp, had found what he assumed was a plastic item in a shrimp, NIVA researcher Bjørnar Beylich contacted him immediately to ask for allowance to analyze the item at NIVA´s laboratory in Oslo.

-  I investigated the shrimp using a magnifier and extracted the putative rubber sphere. Looking more closely at the item, it appeared that it was neither rubber nor plastic; it was something organic, says Beylich.

He emphasizes that the foreign body seems to have been squeezed into the shrimp from the outside, and not ingested by the shrimp.

-    I also found a piece of another shrimp behind the black item. This is probably a bone, or a rostrum, Beylich says.

Bjørnar Beylich, senior engineer at NIVA, studying the organic foreign body at NIVA´s laboratory (Photo: Harald B. Borchgrevink, NIVA).

Knowledge-based decisions

Research manager of water and environmental toxicology research at NIVA, Bert van Bavel, stresses that it is important that decisions regarding plastic use regulations are based on knowledge, and not assumptions. At the same time, unnecessary use of plastic (based) products should be reduced.

-    It is important to increase the knowledge about the sources of plastics, how the plastic is spread in the environment, and their environmental effects, says van Bavel.







Left: The item was assumed to be made of rubber, but turned out to be organic material. Right: The other foreign body found in the shrimp, probably a bone or a rostrum. (Both photos: Bjørnar Beylich, NIVA).

The structure of plastics – a fingerprint

The investigation of the shrimp´s foreign body was done without any high-tech equipment, but NIVA also has the infrared spectroscopy equipment needed for the identification of unknown objects and their origin.

-    By scanning an object – for instance an object you think is microplastic - using infrared spectroscopy, its structure is revealed and you get a “fingerprint” of the object, explains researcher Inger Lise Nerland Bråte at NIVA.

The fingerprint is then tested against a reference database with known substances, and the tested substance is identified.

-    This tool can be used not only to see if an object is plastic or not, but also what type of plastic – and hence it reveals possible sources to the plastic pollution. This ensures a knowledge-based research on microplastics, Nerland Bråte concludes.


Last updated 12.03.2017