How many plastic particles were found in a serving of fish?
Microplastic pollution of our waterways can not only represent a threat to marine ecosystems, but also to human health. It is evident that we are exposed to these pollutants when we consume seafood, which can create a food safety risk. Are some seafood less contaminated than others? The first published study look at in molluscs. By eating an average serving of mussels, you consume around 90 plastic particles, whereas an average serving of oysters may only contain around 50. “As a result, the annual dietary exposure of European shellfish consumers may amount to 11,000 microplastics per year.” However, we don’t know what kind of risk this entails. “Nevertheless, due to their persistent nature, the abundance of microplastics in the marine environment will only increase.”
“It is inevitable that humans eating seafood ingest at least some microplastics, especially in the case of species where all the soft flesh is consumed, such as mussels, oysters and small fish. And the sardines? Researchers look at contamination of canned sardines and sprats by microplastics and mesoplastics (pieces of plastic larger than one millimeter). They investigated 20 brands of canned sardines and sprats from 13 countries on four continents and found plastic particles in around one in five. The researchers suggested that the disparity could be due to improper evisceration of contaminated samples.
We know that ingested microplastics can cross the intestinal wall of mammals and circulate throughout the body and even cross the placental barrier. Do microplastics actually penetrate the muscles of fish, like a fish fillet? This is the subject of my video How much microplastic is found in fish fillets?.
If you compare the level of microplastics in eviscerated flesh compared to excised organs, sometimes flesh actually contains higher microplastic loads than organs, “highlighting that evisceration does not necessarily eliminate the risk of PM (microplastic) ingestion by consumers”. The researchers found that microplastics “with a wide variety of colors, shapes and sizes were detected in all fish muscle samples studied. So that they TO DO actually enter the flesh! The average intake of microplastics from eating flathead, grouper, shrimp, scad, or barracuda can be in the hundreds of plastic particles per 300 gram serving or just the dozens of plastic particles in a 2 ounce child’s serving. “Besides physical injury from ingesting PM (microplastics)” itself, the particles can release absorbed pollutants, such as polychlorinated biphenyls (PCB), as well as plastic chemical additives, such as bisphenol A (BPA), which collectively “can cause endocrine disruption, carcinogenesis and mutagenesis” – i.e. hormonal disruption, cancer risk and DNA damage. “Therefore, although there is no standard dose for ingesting PM (microplastics), as well as information on the exact toxicity of different types of plastic in the human body, taking such high weekly doses (of these types of fish) may threaten the health of consumers (especially vulnerable groups including pregnant and breastfeeding women and children).”
In the United States, anthropogenic debris, i.e. man-made materials, have been find in one-quarter of individual fish and two-thirds of all fish species tested, and about one-third of individual shellfish samples. This demonstrates that man-made debris “has infiltrated marine food webs” – the aquatic food web – “down to the level of humans via seafood. Given that anthropogenic debris is associated with a cocktail of priority pollutants, some of which may be transferred to animals upon ingestion, this…reinforces concern that chemicals from anthropogenic debris could be transferred to humans via diets containing fish and shellfish, raising important questions regarding the bioaccumulation and biomagnification of chemicals and consequences for human health. The study also included non-plastic debris, such as foams, films and fibers, but we know now that the ingestion of microplastics “appears to be a widespread and ubiquitous phenomenon” in a number of commercially important shellfish and fish.
“The potential for humans, as top predators, to consume microplastics as contaminants in seafood is very real, and its health implications need to be considered…Despite the existence of considerable uncertainties and unknowns, there is already a compelling case for urgent action to identify, control and, if possible, eliminate major sources of…microplastics before they reach the marine environment.”
To know more about this subject, see in my videos Microplastic contamination and seafood safety And Are microplastics in seafood a cancer risk?.
What about the proposed benefits of eating fish? See my videos Omega 3s and the Eskimo Fish Tale And Is fish oil just snake oil? to learn more.