Are We Eating Plastic Pollution?
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Plastic is ubiquitous. Suppose plastic is not physically within your immediate field of vision. In that case, it might be chemically incorporated in the form of microplastics into the products that you regularly consume - including within our food and water supply.
The mass production of plastic has a devastating impact on our terrestrial and marine wildlife, whether it be through accidental ingestion or direct entanglement in waste. Though less visible, microplastics play a similar hand in polluting both our environment and wildlife digestive systems.
In turn, through our consumption of contaminated seafood, microplastics can potentially act as a toxin to humans. For the sake of our environmental and human health, it is important to seek areas of change in the harmful life cycle of plastics.
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What are microplastics?
Microplastics are tiny pieces of plastic (less than 5 mm) derived from various sources, such as the degradation of larger plastic materials. Other processes of releasing plastic fibers into our air and waterways include washing synthetic clothes or wearing down vehicle tires.
Microplastics, known as microbeads, can also be intentionally added to cosmetics, paints, and fertilizers. Due to their size, these microplastics are not detected by traditional wastewater treatment processes.
This small size and inability to be detected allows microplastics to sneak into essentially every water source, and every nook and cranny of the planet. Plastic is entering the food chain, and while plastic pollution may seem like a far off problem, we are eating microplastics too.
The journey from land, to the ocean, and back to land
The Great Pacific Garbage Patch, located in the waters between Japan and North America, is a vortex of marine debris. The vortex is an accumulation of various industrial wastes, with the majority being fishing equipment and plastics. Contrary to its name, the Garbage Patch is not only a physical collection of floating, swirling trash. Instead, a large portion of the marine plastic debris found is microplastics.
In 2017, the UN estimated that 51 trillion microplastic particles, about 500 times the amount of stars in our galaxy, were in the ocean. Over 80% of ocean plastic originates from land due to mismanaged waste. Despite the abundance of microplastics in the ocean, they cannot readily be seen by satellite imagery or even by unsuspecting wildlife.
As microplastics end up in our waterways, they end up in the bodies of freshwater and marine animals as small as zooplankton. Plastic cannot break down within animal digestive systems and can reach high concentrations within a single organism. This build-up of toxic substances is known as bioaccumulation.
When larger fish consume smaller fish, the collected bits of plastic are eaten along with them. A study estimates that one humpback whale had up to 160 undigested plastic bits within its body upon its death.
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As a result, large animals end up with high toxins concentrations from ingesting a mass of these smaller fish and plankton. This process, known as biomagnification, means that plastics, and other harmful toxins, can gradually move up the food chain. For example, mercury poisoning in humans can be attributed to biomagnification in seafood and is prominently known for causing neurological and congenital disabilities.
Microplastics have snuck their way into a majority of food chains, if not all. Studies estimate that microplastics' annual ingestion can range from 37 to 11,000 particles from sea salt and shellfish, respectively. Plastic particles are even capable of contaminating air, and research suggests that the average American in total ingests 74,000 particles annually.
Unfortunately, it is difficult to assess how microplastics directly affect human health due to the ethics in scientific experimentation of humans. Still, it is important to think about the harmful nature of plastic production itself and the proven effects of plastic on lab animals.
Why eating plastic is probably as dangerous as it sounds
Plastic is a synthetic polymer or compound made from petroleum oil. During manufacturing, plastic is combined with additives such as plasticizers to enhance their usability. Notable additives include bisphenol-A (BPA) and phthalates, which are both proven to be significant endocrine disruptors in lab animals.
Due to its physical properties, plastic is capable of adsorbing harmful heavy metals and other chemicals from the environment. Persistent organic pollutants can even accumulate in ocean trenches as deep as 10,000 meters and are also chemically attracted to plastic pieces. With its durability, plastic can act as a physical vector for harmful contaminants and spread them far throughout the ocean.
Research experiments have found that ingesting polyethylene plastics causes reduced liver function and stress in fish. Another study found that crabs and mussels had impairments in their respiratory and immune systems following exposure to microplastics. Shellfish are of particular concern to humans because we typically consume the entire organism compared to specific fish parts.
Further research must be conducted to understand how microplastics affect human health. Though the long-term effects of microplastics and other pollutants are not well understood, we can still take action to reduce plastic consumption, protect our oceans, and lessen the possible risks on human health.
Photo by Brian Yurasits on Unsplash
What Can We Do?
Though it may not be feasible to eliminate seafood from our diet completely, we can make individual choices to shop more sustainably. For example, fish at lower trophic levels are less prone to biomagnification of harmful substances and generally more sustainable. On the other hand, bluefin tuna, eel, and Chilean sea bass should be avoided, especially as they are prone to becoming overfished. The Monterey Bay Aquarium Seafood Watch is a helpful resource for identifying sustainable seafood options based on fishing, ecological importance, and more.
Microplastics are said to originate on beaches as abundant sunlight aids in the degradation of larger plastic material. Through high winds and tides, they are carried further into the ocean. On the local level, organizing beach clean-ups and raising awareness about litter is a simple way to fight microplastics.
On a federal level, we can push for beneficial policy decisions regarding the usage of plastics. For example, in 2015, the Food and Drug Administration enacted The Microbead-Free Waters Act, banning the intentional use of microplastics in commercial products. The final deadline for industrial compliance was set back in 2019, meaning there should be no microbeads in our cosmetics today.
Beyond cosmetics, all industries are responsible for reducing the amount of plastic being produced and distributed. After all, if it isn’t being produced, it isn’t polluting.
To follow suit, we can encourage businesses to eliminate their use of single-use plastics and emphasize the importance of reusable packaging. Additionally, it is important to increase regulation on fishing industries, whose nets and traps compromise at least 10% of plastic waste in the ocean.
As microplastics' biomagnification is an issue that only gets worse over time, it is important to push for these societal changes with urgency. Though we may currently be unsure of the health implications of ingesting microplastics, there is no reason for us to take potential risks if we can minimize wasteful practices. As we continue polluting our environment, we will end up polluting our bodies in return.