Plastic found in every mouthful of seafood

…with sardines the most contaminated dish

DINERS are unwittingly swallowing plastic in every fish meal, researchers fear.

A study of five different fish types found they were all contaminated with plastic, with sardines containing the most.

Researchers bought oysters, prawns, squid, crabs and sardines from a market and analysed them using a newly developed method that identifies and measures five different types of plastic simultaneously. Microscopic particles were present in the flesh of all the fish, the researchers said.

The study – by the University of exeter and the University of Queensland – found plastic levels of 0.04 milligrams per gram of tissue in squid, 0.07mg in prawns, 0.1mg in oysters, 0.3mg in crabs and 2.9mg in sardines.

Lead author Francisca Ribeiro, who conducted the research as part of her PhD, said: ‘Considering an average serving, a seafood eater could be exposed to approximately 0.7mg of plastic when ingesting oysters or squid, and up to 30mg of plastic when eating sardines, respectively. For comparison, 30mg is the average weight of a grain of rice.

‘Our findings show that the amount of plastics present varies greatly among species, and differs between individuals of the same species. Sardines had the highest plastic content, which was a surprising result.’

The Daily Mail has long campaigned against plastic pollution with our Turn the Tide on Plastic campaign, and is urging readers to take part in the Great September Spring Clean between September 11 and September 27.

Preventing litter can stop plastic entering the ocean via rivers.

Co-author Professor Tamara Galloway, of exeter’s Global Systems Institute, said: ‘we do not fully understand the risks to human health of ingesting plastic, but this new method will make it easier for us to find out.’ The researchers bought raw seafood – five wild blue crabs, ten oysters, ten farmed tiger prawns, ten wild squid and ten wild sardines at an Australian market.

The plastics they tested for – polystyrene, polyethylene, polyvinyl chloride, polypropylene and poly(methyl methacrylate) – are commonly used in packaging and synthetic textiles and are frequently found in marine litter.

In the new method, the tissue is treated with chemicals to dissolve the plastics in the samples. The resulting solution is analysed using a technique called pyrolysis gas chromatography mass spectrometry, which can identify the different kinds of plastic in the sample at the same time.

Polyvinyl chloride was found in all samples, while the plastic found in highest concentrations was polyethylene.

Studies show microplastics not only enter our diet from seafood, but also from bottled water, sea salt, beer and honey, as well the dust that settles on our meals.

The study was published in the journal environmental Science & Technology.