A recent Australian study found plastic in all samples of popularly consumed seafood.
The study recently published in Environmental Science & Technology discussed how small pieces of plastic contribute to pollution all over the planet, including the sea, where these microplastics are eaten by marine creatures and then entered into human diets through seafood consumption, according to the study’s news release.
“Microplastic contamination of the marine environment is widespread, but the extent to which the marine food web is contaminated is not yet known,” the investigators stated in the study.
The researchers bought raw seafood from a market in Australia: five wild blue crabs, 10 oysters, 10 farmed tiger prawns, 10 wild squid and 10 wild sardines. They then analyzed them for five different kinds of plastics commonly used in packaging and typically found in marine litter. The researchers found plastic in every sample tested, according to the study release.
“Considering an average serving, a seafood eater could be exposed to approximately 0.7 mg of plastic when ingesting an average serving of oysters or squid, and up to 30 mg of plastic when eating sardines, respectively,” lead author Francisca Ribeiro stated in the press release.
The researchers at the University of Exeter and the University of Queensland found the highest levels of plastic in the study size sampling of sardines (2.9 mg) and the least amount in squid (0.04 mg). Crabs (.3 mg) were second-most, followed by oysters (.1 mg) and prawns (.07 mg). For comparison reasons, the average weight for a grain of rice is 30 mg, the researchers stated
The researchers used a new method of detecting five different types of plastics simultaneously in the seafood samples, they 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,” co-author Tamara Galloway, a professor at the University of Exeter, said in the news release.
The new method includes treating the tissue samples with chemicals to dissolve the plastics found in the seafood, according to the researchers. The solution is then analyzed using a technique called Pyrolysis Gas Chromatography-Mass Spectrometry, which the researchers explained can identify different kinds of plastic in the seafood sample simultaneously.
Polyvinyl chloride, known as PVC, was found in all samples, while the plastic found in the highest concentrations was polyethylene, which is often used in laminates and film. The study authors stated in the release that the new testing method is a step toward defining what levels of microplastics are considered detrimental to a person’s health, as well as analyzing the risks of ingesting microplastics in food.
The researchers also noted that the risk of microplastic ingestion in humans does not stop at seafood but can also occur through bottled water, beer, sea salt and honey.