Brief Introduction to Microplastics
Before diving into the topic of microplastics, Plastic has brought modern conveniences to mankind. Plastics can remain sterile, it’s a flexible material, strong but lightweight and of course, it’s cheap to manufacture. That’s why, almost any industry, like food and manufacturing, transportation, the infrastructure just to name a few, has all been touched by plastics. Among the industries that have greatly benefited from the use of plastics are the food & packaging and the health/medical industry. For example, milk is now in plastic bottles (mostly PET or polyethylene), making it easier to transport and can withstand light to medium impacts during transportation and handling. Plastics also made it possible to have disposable syringes, which are not just for convenience but also to maintain sterility. Plastic has become an economic workhorse for the modern world.
But despite the modern conveniences it has brought to mankind, once was hailed as a scientific marvel, it is now an environmental hazard. But in recent years, there is now a growing concern about plastic parts that are ending up in fishes and other benthic marine organisms, like oysters and clams just to name a few. It’s what scientists call “microplastics”. With this problem, plastics are now becoming a public health concern.
To make you understand, here is a brief introduction to Microplastics.
- So what are Microplastics? Plastics, in general, are made up of polymers (carbon-based) and they can be made from a material that can either be naturally derived or completely synthetic. A plastic becomes microplastic when it is subjected to an external force, breaking from a larger piece into smaller ones called Secondary microplastics. While Primary microplastics are plastics that are used to make large plastic items or as a primary material (ex. micro-beads, nylon fibers for clothing, pellets, and many more). Plastic material can be considered microplastic if it measures <1 mm in size. While macro plastic is any plastic >1mm.
Note. If you are curious on what are the classifications of plastic, click here.
- What are the possible sources of Microplastics – Microplastics can have multiple sources, although it’s possible to determine their exact source once they are in the environment. The Source of Microplastics can come from micro-beads (face washes, toothpaste, cosmetics, etc.). Clothes that contain synthetic fibers such as nylon, and polyester. Other sources also include macro-plastics like plastic bottles, plastic bags, paint from chipping just to name a few. Industries like agriculture and manufacturing also contribute to the appearance of microplastics in the environment.
- So How do they end up in various places? Especially in marine and freshwater environments. Rain and water runoffs. When it rains, small bits of plastics are washed off, either from landfills, homes or residential places, commercial and industrial areas too As it rains, it also collects microplastics along the way, eventually ending up in various bodies of water. Another way for microplastics to end up in freshwater and marine bodies is through the sewage system. By using products with microplastics ( washing your face with a cleanser or doing laundry) a lot of it ends up going to water treatment and sewage systems. During this process, those microplastics are small enough to pass through the filtration or the sewage system, and that’s how they too end up in oceans, lakes, and many more. It has been studied that a lot of habitats has been contaminated with microplastics.
Lastly, How do microplastics end up in marine & freshwater organisms, possibly humans? Due to their size, microplastics can pass through a sewage system and once they end up in various bodies of water, they can be further reduced to nano plastics. Microplastics are now a subject of intensive research especially now that they have been found to accumulate in fishes and other marine organisms (oysters, shrimps, tuna, etc.) So far, studies have shown that there is an issue of bioaccumulation (smaller fish gets eaten by a larger fish, and then the larger fish will be consumed by humans). In the case of invertebrates such as oysters, they are so-called filter-feeders. This means they draw water in and filter for tiny microorganisms, and that somehow also allows microplastics to get into their system. Since plastic doesn’t degrade, they just accumulate in the bodies of these organisms over time, including humans. Either from ingesting it or through food consumption. In terms of the possible effects of the accumulation of microplastics, scientists are still figuring out the chemical or toxicity aspect of microplastics to fish and other marine organisms. But it’s good to be wary that some of our actions regarding waste management are literally affecting each and every one.