Written by Jacob Liu | Edited by Mehr Bawa
Photo by Lucien Wanda
Found in soda bottles to car tires, most plastic polymers all end up degrading into microplastics. In fact, microplastics have been found in our oceans, the seafloor, droplets of rain, the air which we breath, and even on mountaintops like Mount Everest [1]. While environmental impacts of microplastic pollution have been well-studied in the past few decades, a recent study published in Environmental International found significant quantities of microplastics present in human blood [2]. The effects of microplastic pollution on human health up until this point have been largely theoretical, with only a few artificial case study experiments involving possible mechanisms of harm. However, the once-theoretical danger has now become an issue in which scientists are racing to catch up.
Microplastics are often defined as plastic particles up to 5 mm in diameter [2]. These microscopic particles result from the degradation of plastic polymers from items including plastic bags, synthetic fabric washing, and car brakes and tires. They are so prominent that measurements in protected areas in the Western United States have the equivalent of 120 million plastic bottles worth of microplastics falling just in the annual rainfall [3]. However, studies into these microplastics, including their measurement and regulation, still remain debated worldwide. Nonetheless, a conglomerated study from the University of Newcastle found that people consume 5 grams of plastic every week, roughly the equivalent weight of a credit card [4]. While microplastics can differ in how they react to the environment chemically, there is a trend of toxic byproducts resulting from extremely long processes of plastic degradation lasting thousands of millions of years. That is not even counting the physical aspect of plastic pollution—the bits and pieces [5]. The buildup of plastic pollution in the environment is already present in marine life, which has been observed to ingest macroplastics. In fact, this has prompted researchers to analyze microplastic buildup and how they permeate into our environment largely unseen, including leaching into groundwater reservoirs and being dispersed as air pollution [6].
As microplastics’ environmental impacts are still being studied, research about microplastics’ effects on humans has fostered discussion about the general health impact on microplastics. Studies artificiated with testing on in vitro human cell lines have found toxic effects on cells, overactive immune response, oxidative stress, and membrane barrier integrity attributed to microplastics [3]. However, these studies were largely focused on cell cultures isolated from humans; there still remain concerns for how microplastics affect the complex tissue and organ systems of an entire organism. Further research on the trend of irregular cellular shape stretching associated with microplastic effects predicting cell death have found that microplastics attach themselves to the membranes of cells, stretching the membrane and leading to serious dysfunction of general cell machinery and significant reduction of cell lifetimes [1].
As ongoing research uncovers more about the microplastics prevalent in our environment and now even our blood and bodies, we must turn to treating conditions on a case-by-case basis given our superficial understanding. Eventually we should work towards removing microplastics from our bodies, and more importantly, our environment. From there, we can consider how to mitigate the use of microplastics, reuse plastic polymers currently present in our lives, and develop new, environmentally-conscious alternatives.
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