Right now, you might be sipping your coffee or tea while enjoying the newspaper. But you might not know that, along with the morning coffee that warms your hands from the plastic-lined paper cup, you also just ingested 25,000 particles of microplastic. Unfortunately, just removing your morning coffee from your routine will not rid you of these micro and nanoplastics. The clothes you wear, the gum you are chewing, or even the mascara on your eyelashes, are all most likely made of plastic. Even the air we breathe now contains nanoplastics. When larger plastics in the environment break down, polystyrene nanoplastics (PS-NPs) are produced. These little particles are found on the top of Mt. Everest, where only 0.000077% of the population has ventured. They are found in all organs of our body; the lungs, the brain, even sperm and eggs. In fact, a 2024 study found the equivalent of a standard plastic spoon’s worth (about 7 grams) of micro- and nanoplastics in the average human brain, which is approximately 0.5% of the brain’s weight.
Plastics weren’t always ubiquitous. In fact, before WW2, most people would not even know what the term ‘plastic’ refers to. And maybe you do not even know the real definition. The definition of plastic, defined by Britannica, is a polymeric material that has the capability of being moulded or shaped, usually by the application of heat and pressure. Natural plastics, horns, tortoiseshells, amber, rubber, and shellac have been around forever. Prior to mass production, animal horns were heated and used to make various items like cutlery and combs. However, during the second industrial revolution, animal horns became scarce as many horn-bearing animals, like elephants, were facing extinction. The pressure of this new environmental and economic problem called for a new semi-synthetic material that was more ‘sustainable’. The first fully synthetic plastic made by Leo Baekeland, a chemist, in 1907 was named Bakelite. It was the result of combining formaldehyde and phenol under heat and pressure. As the industrial world progressed, the reliance on oil increased; thus, the Imperial Chemical Industries (ICI) wanted to find a use for the waste material, ethylene gas, made from processing crude oil and natural gas. In a failed experiment of trying to combine ethylene and benzaldehyde, the ICI discovered a polymer of ethylene in the process, polyethylene, which is currently the most widely used form of plastic. From here on, plastic manufacturing skyrocketed. It began being used for Tupperware, then nylon and Teflon were created.
At the time, this invention seemed like a sustainable option. We were no longer endangering species, and we were even putting the waste from processing oil and natural gas to good use. However, like most ideas in human history, we did not predict the future implications of plastic. Now, as we are more reliant on plastic than ever, we are starting to see the not-so-pretty side of things. Firstly, degradation takes a long time. Depending on the material, some items can take thousands of years to decompose, but most items take a couple of hundred years. This means that we have a plastic pollution crisis. We are finding islands of plastic in our oceans, and it is interfering with almost all ecosystems. The Great Pacific Garbage Patch is just one cluster of ocean plastic, and it alone is estimated to be roughly three times the size of France. But not only are plastics destroying our external environment, they are destroying us internally.
Is the plastic in our bodies actually harmful? New research led by Trinity’s Dr Gavin Davey and undergraduate Devin Seward suggests yes. They reveal that the nanoplastics found in our brains may interfere with our energy and brain function, which may lead to neurological damage and disease. The team researched mitochondria, the cellular body responsible for producing energy for brain function. Their process began by isolating the mitochondria from the brain cells. In doing so they were able to see the direct effects of these PS-NPs on the mitochondrial function. The data revealed that exposure to PS-NPs disrupted the electron transport chain, a set of protein complexes that work in conjunction to produce cellular energy as ATP (adenosine triphosphate), an organic molecule found in all living cells that serves as the primary energy carrier, storing and transferring energy needed for cellular processes. Along the electron transport chain, there are complexes numbered I through IV, which, along with coenzymes, facilitate the transfer of electrons and the generation of an electrochemical gradient to produce ATP. In brief, complex I transfers electrons and pumps protons into the intermembrane space, which increases the acidity inside the cell; complex II simply transfers electrons, and complex III transfers more electrons and pumps additional protons across the membrane. Importantly, all of these complexes play a huge role in the transfer of electrons, which is imperative for a cell to produce ATP. Through their experiments, the team discovered that complex I and II were not directly affected. However, electron transfer between complexes I-II and II-III were potently inhibited at lower concentrations. These same results also appeared in synaptic mitochondria, which are responsible for the communication between brain cells.
There are several conclusions that can be made from these results. If these nanoplastics are impairing our mitochondria’s ability to produce energy, then this can lead to cellular damage and death, and then neurological disease. If the accumulation of nanoplastics interferes with synaptic plasticity, then they can inhibit the ability to learn, memorise, and remember. As lifelong students and future leaders, this knowledge is not only important for our own health, but also important as we may be future lawyers who write legislation banning single-use plastics. We may be future scientists who help discover new bacteria that can degrade plastics. We may be future engineers who develop a better and more sustainable alternative to plastics. We may be future economists who find a material that is not only affordable but also good for the environment. We can help make the change and prevent more damage from being done.
Although new research suggests that we may be able to remove nanoplastics from our bodies, these technologies are in the preliminary stages. However, there are concrete ways to prevent more ingestion of nanoplastics. The easiest changes you can make to your lifestyle in regards to limiting plastic intake start in the kitchen. By removing items like plastic cutting boards, plastic utensils, and plastic packaging and replacing them with wood, glass, and stainless steel alternatives, you are already making a substantial difference. Furthermore, any combination of heat and plastic is fantastic if you are trying to ingest more microplastics. These include plastic-lined coffee cups from Starbucks, your plastic tea bags, or even quick meals that are packaged in plastic and heated up in the microwave. Additionally, your water consumption can also lead to more plastic in your system. Although tap water is better than bottled water, both are proven to contain microplastics. Even a simple carbon filter can reduce microplastics by 90%. Lastly, trying to move away from synthetic clothing is another easy change that can go a long way. Simply being aware of this secret toxin will allow you to make better choices that will add up to make a huge difference in the amount of nanoplastics in your system.
