In a new study from the Universitat Autònoma de Barcelona, researchers have determined that plastic contamination found in shrimp does not pose a threat to their health or to the health of the humans that consume them.
The investigation was focused on shrimp from three fishing zones in the Mediterranean Sea. Some of the samples, which were collected in 2017 and 2018, were compared to samples from the same sites collected 10 years ago. This made it possible for the researchers to establish the changes in microplastic concentrations over the ten-year period.
Three out of every four shrimp examined in the study contained plastic fibers in their digestive tract. Nearly half of the affected shrimp had a large portion of the fibers tangled into a ball inside their stomach.
In one specific sample, shrimp collected off the coast of Barcelona had up to 30 times as many synthetic fibers as those from other fishing zones.
Surprisingly, there was no significant increase in the abundance of fibers among shrimp collected in 2017-2018 when compared to the 2007 samples. The main difference was that the composition had changed over time, shifting from acrylic polymers to polyester.
The researchers found no evidence to suggest that the presence of plastic fibers had an adverse impact on the health of the animals. All of the shrimp, including those with a considerable accumulation of fibers, were in good health. For example, no damage was observed in the organs analyzed, not even in the tissue that came into direct contact with the artificial fibers.
“The shrimp probably get rid of all of the fibers they ingest and accumulate thanks to the shedding of their exoskeleton which takes place every so often, and this could explain why although an abundance of these fibers have been found in some shrimp, they continue to show signs of being healthy,” explained study co-author Ester Carreras.
According to the researchers, “the consumption of shrimp is in no way a contaminating agent that should concern us.”
“Other studies show that ingesting microplastics through shrimp is minimal in comparison to the amount of fibers entering our bodies through other means, such as the use of plastic packagings or environmental contamination, or through the synthetic fibers in clothes and also those found in dust and which inevitably also end up in our plates,” said Carreras.
A previous study in the UK estimated that an individual ingests 14,000 to 68,000 microplastic particles from in the dust and air each year. With this in mind, the average of 22 fibers found in shrimp would not be harmful – especially considering that 90 percent of the particles were located in the shrimp’s “head,” which is usually not eaten.
“Soon it will be time to discover whether common commercial fish from our coastal waters such as red mullet, surmullet or striped mullet, and anchovy, follow the same path,” said Carreras.
The study is published in the journal Environmental Pollution.