Summertime is the perfect time for seafood. There are few pairings as refreshing as chilled rosé and raw oysters and the duo makes for the perfect happy hour indulgence. However, a new study details a disheartening discovery about your favorite mollusks and crustaceans—they all contained traces of plastic.
The study, which was published in the journal Environmental Science & Technology, was conducted by a team of researchers from the University of Exeter and the University of Queensland. Researchers examined oysters, prawns, squid, crabs, and sardines from a market in Australia and found that each sample had been contaminated with plastic.
The lead author Francisca Ribeiro from UQ’s Queensland Alliance for Environmental Health Sciences clarified that the study was a stepping stone to better understanding the potential side effects of ingesting microplastics found in various seafood.
“We found polyvinyl chloride – a widely used synthetic plastic polymer – in all samples we tested, but the most common plastic in use today – polyethylene – was the highest concentrate we found,” Ribeiro said.
Microplastics, as the name would suggest, are very small pieces of plastic that taint the ocean. As a result, marine life and other organisms inevitably end up eating them. From the seafood tested above, Ribeiro says that sardines by far had the highest concentration of plastic at 2.9 milligrams per gram of tissue. Plastic levels in squid, prawns, and oysters were much lower at 0.04, o.07, and 0.1 milligrams, respectively.
The findings made it possible to roughly quantify how much plastic a seafood eater consumes. For example, an average serving of oysters or squid could expose a person to about 0.7 milligrams (mg) of plastic. When eating a serving of sardines, a person could ingest as much as 30 milligrams.
“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,” said Ribeiro.
The study also enabled researchers to define what microplastic levels are potentially harmful to human health by employing a plastic quantification technique that allowed results to be reported in mass units.
Seafood isn’t the only thing you eat that’s polluted with microplastics. In fact, bottled water contains sea salt, beer, and honey are all known to contain traces of the substance. For context, a study published in the same journal last year found that humans consume anywhere from 39,000 to 52,000 microplastic particles each year. More research needs to be done before we know what dose of microplastics is detrimental to human health, but if anything, this new study details how much of the synthetic material is found in some of your favorite seafood appetizers.