Microplastics are invading the world’s water sources. Plastic wastes less than 5mm are microplastics.
Primary microplastics are artificial for personal and industrial use. Secondary microplastics originate from the degradation of plastic waste. UV radiation from ocean waves and the sun break down the plastics thrown in oceans and rivers, creating microplastics.
These microplastics can be found throughout the ocean, floating at the surface, within the water columns, and they also tend to cover the seabed where it harms the ecosystem that feeds on the seabed. In plastic polymers (PBDEs), pigments, fillers, plasticizers, heat and UV stabilizers, and flame retardants are all in plastic polymers (PBDEs). These compounds can seep into nearby water, posing a risk to both the environment and human health.
Microplastics in fish
Fishes in oceans are not the only ones who ingest microplastics. Microplastics have also been found in fish and other marine species caught and bred for human consumption. Microplastics are also present in freshwater. Freshwater species such as carp and tilapia have been reported to consume microplastics.
Pollutants such as PCBs and pesticides attach to the microplastics in the oceans, and thus the microplastics become more concentrated. Clams, scallops, mussels, and oysters are filter feeders that filter particles from seawater. Studies indicate that microplastics harm the gills of shellfish. Scientists identified plastic particles in every filter feeder investigated in a new study of microplastics in the deep sea. Chemical leaching from microplastics also affects marine photosynthetic algae, which contributes to producing oxygen.
In fish, microplastics were found primarily in the gills and the digestive tract. Microplastics and smaller particles than microplastics, known as nano plastics, can migrate from a fish’s gut to its muscular tissue, which is the part that humans consume. Because plastic particles are commonly concentrated in an organism’s digestive tracts, bivalves, so small fish eaten whole, are more likely to expose humans to microplastics.
As the global ocean plastic pollution rises, fishes will likely swallow more plastic over time.
Effect on the human body
The presence of microplastic in fish is a potential threat to human health. However, humans consume microplastics through fish and other ways such as bottled water, tap water, and air, and those are a more significant threat than ingesting microplastics through fish and seafood.
Given the high consumption of seafood around the world, human exposure to microplastics is unavoidable. The excretory system of the human body likely disposes of more than 90% of ingested microplastic and nano plastic. The size, shape, polymer type, and additional chemicals of microplastics swallowed by humans are all factors that affect how much is excreted.
The nature of the hazardous chemical, individual sensitivity, exposure parameters, and hazard controls all influence the intensity of adverse effects caused by exposures. Although researchers do not have clear answers as to how consuming these microplastics will affect human health or in what quantities they would be dangerous. Preliminary research has revealed some potentially harmful consequences, including increased inflammatory response, microbiota alteration, plastic particle size-related toxicity, and chemical transfer of adsorbed chemical pollutants.