In March of 2022, scientists discovered plastic in human blood for the first time. In a study published by the Environment International peer-reviewed journal, almost 80% of the 22 healthy test subjects had small plastic particles or “microplastics” in their blood samples.
Scientists in the Netherlands published this discovery in May of 2022. The scientists used gas chromatography and mass spectrometry, both of which are incredibly powerful and sensitive analytical techniques capable of measuring particles as small as 700 nanometers. After analyzing the blood samples of 22 healthy random volunteers, the researchers discovered four types of polymers that are typically found in plastics: polyethylene terephthalate, polyethylene, styrene and polymethyl methacrylate.
These are the types of plastics that you’d typically find in several regular products, like paints, adhesives, plasters, finger paints, polymers, plastic bottles, cosmetics and personal care products. The average concentration of these plastics was approximately 1.6 µg/L. According to the advisory board, 1.6 micrograms per L is just about the equivalent of “one teaspoon of plastic per the amount of water in ten large bathtubs”. That doesn’t sound like a lot but even the smallest amount of plastic can be incredibly dangerous to the human body. This study was extremely groundbreaking — not only for its troubling findings, but for helping us understand that the human bloodstream can indeed uptake plastic particles. Once plastic is within the bloodstream, it can be carried to other parts of the body.
This is by no means the first time we have seen evidence of microplastics in human tissue. Plastic particles have been discovered practically everywhere; in human feces, placentas, several organs and now, the blood that circulates and replenishes our entire body.
How Plastics Impact Humans
Where can we go from here? Firstly, we can continue to conduct studies to replicate these findings using larger samples to further strengthen the results of this experiment. We should also determine the effects of plastics in our body — although some research has already begun to shed some light on this.
In 2020, scientists also discovered that bottle-fed babies swallow millions of microplastic and nanoplastic particles every day, which is evident in babies’ feces. They noted that the “recommended high-temperature process” that parents follow to clean the bottle and prepare formula milk makes the bottle shed polypropylene particles. They found that the bottles fed as much as 16 million particles per litre. They made this discovery by accident, when one researcher was developing filters and found that their filters “kept getting clogged with microplastics.”
Because they detected the microplastics in the infants’ feces, this surely means that they excrete the plastic as waste, right? Unfortunately, our new discovery of microplastics in blood is now a point of concern because it indicates the fact that plastics undoubtedly can enter our body’s bloodstream.
In January of 2021, scientists also found microplastics in human placentas. The microplastics were both on the fetal and maternal sides and they decidedly could travel through the bloodstream. Microplastics are foreign objects; they can trigger immune responses which deplete maternal and fetal stores of energy. How can this impact the fetus? Immune reactions are powerful; activated immune cells can secrete inflammatory molecules that can interfere with growth signaling, leading to adverse effects like preeclampsia and fetal growth restriction.
Some things remain unknown. For example, what proportion of our ingested microplastics will be excreted in feces versus absorbed into our bloodstream? Can the plastic get past the blood–brain barrier and actually enter the brain? In pregnant rats, scientists observed in 2020 that plastic can move through the placenta into the fetus’s bloodstream, and ultimately reach the heart, brain, lungs, liver and kidneys. Another 2021 study found that microplastics can latch onto red blood cells and mechanically stretch their cell layers, causing the cells to significantly lose their stability and their oxygen-carrying ability.
So we know that other mammals like rats can uptake microplastics into their brain and other organs. We also know that plastics can reduce our blood cells’ ability to transport oxygen. How will this impact growth in children? Do the pigments from the paint on plastic items also impact humans? How will the plastics impact our organs — could they make us more vulnerable to disease?
According to a review from March 2022, they absolutely can. Micro and nanoplastics chemically act as “vectors” of substances that have toxic effects, including the industrial chemical bisphenol A (BPA), which is commonly used in producing plastics and is a known disrupter of hormonal balance in the body, having been linked to cardiovascular disease and type 2 diabetes. Microplastics can transport these harmful chemicals into your body, almost as a “Trojan Horse effect.”
Micro and nanoplastics can also alter our microbiome. The microbiome refers to the thousands of bacteria that live within our gut. They are symbiotic, meaning that they help us metabolize our ingested foods. The more diverse our microbiome is, the more resilient our gut is to metabolic fluctuations. If you lose diversity, your risk of chronic metabolic disorders significantly increases, including diabetes and ulcerative colitis. Human studies have shown that BPA can and will survive degradation in the human digestive tract; even when passing through our acidic stomach and our alkaline gut, BPA is not completely degraded and instead reduces the diversity of our gut microbiome.
Scientists still need to research how this happens. Is it because the microplastics themselves are covered in external bacteria that outcompete and kill our gut bacteria? Or is it caused by interference from the plastic itself? Another plastic agent called di-(2-ethylhexyl) phthalate (DEHP) can also disrupt the microbiome and has been linked to a disruption in immune regulation in children, which has significantly exacerbated allergy development. Finally, researchers have observed toxicity in nanoparticles, including increasing cell stress, damaging DNA and even destabilizing mitochondrial and overall cellular integrity. This is unfortunately a hallmark sign of carcinogenicity — meaning that they very likely play a role in tumor development.
There is still so much to research and explore, but so far, the evidence points to microplastics being harmful to humans. We are exposed to plastics every day. Even if we dispose of all plastic, plastic takes a ridiculously long time to decompose, whether it’s 20 years for a plastic bag or up to 500 years for plastic cups and plastic toothbrushes. During the time that it spends accumulating in oceans and landfills, microplastics can get eaten or picked up by microorganisms, including plankton and even plant-pollinators, impacting their physiology and eventually reaching us yet again through the food chain.
How Did the Plastic Pile Up?
Plastic has become ubiquitous. According to the UN, the world produces approximately 400 million tonnes of plastic every year. But it wasn’t always this way. Companies like Coca-Cola used to collect used glass bottles and reuse them. They switched to predominantly using plastic bottles in the 1950s. With the last production of their iconic glass bottles ending in 2012, it’s rare to ever see the popular drink in glass bottles. This happened thanks to a campaign that beverage companies, including Coca-Cola and Dr. Pepper, pushed called Keep America Beautiful, which shifted blame away from companies producing plastic bottles and onto consumers for increasing waste, coining phrases like “keeping America beautiful is your job” and “every litter bit hurts.”
The companies publicly broadcasted this message while quietly lobbying against regulatory bills in the US that would require them to reduce waste. As a result, they successfully led a campaign that has allowed them to dump waste, primarily plastic, in lower-income countries, including India, Indonesia, Malaysia, Pakistan, Senegal, Thailand, Turkey and Vietnam. As a result, companies get to offset costs and increase profits while making pollution and waste a public problem. Although Coca-Cola has claimed to begin using recycled plastic, this is often a half-truth to appease a worried public. The truth is that only some plastics can be recycled, they can only be recycled once, and they are often lower in quality. In reality, glass bottles do not pose the same health risks, nor do they pose nearly the same number of toxic effects, although they are sometimes heavier and more prone to breaking. With greater accountability and regulation imposed upon the mass producers of plastic like Coca-Cola and Dr. Pepper, we can begin to use more sustainable and reusable containers for our beverages.
We should also consider alternatives to plastic in clothing. Although this may be an uncomfortable topic, leather items often last for decades thanks to the sheer endurance ability of real full-grain leather. There are records of leather horse saddles from the 1890s, still intact today. Although non-animal “leather” alternatives like vegan leather are used, the drawback is that they are often made of plastic. There are also other alternatives, such as simply using more environmentally friendly materials that do not use synthetic fibres, such as cotton and linen. It’s also time to speak about the incredibly wasteful nature of “fast fashion,” a general trend of mass clothing production which, although cheap, is often poor in quality and quickly gets thrown out. Many social media apps like TikTok have propagated fast fashion, leading to devastating clothing wastage and news stories like the massive heaps of clothes that washed up on the shore of Ghana in July 2022.
Cleaning Out the Plastic
What about the plastics that remain in the environment today? Do we have any hope of cleaning them out? Fortunately, scientists have posed many potential solutions. For example, we can use a chemical process called electrolytic oxidation, which uses electrodes to simply generate free radical hydroxides that can attack microplastics and break them down into harmless molecules. Since microplastics are often concentrated within wastewater, scientists can implement the oxidation method at this point to eliminate the microplastics before they reach humans. Another way is to use “flocculants,” which are chemicals that attract and clump together with plastic particles. Once they form the clump, they sink, allowing for water treatment facilities to filter them out. One of the most effective flocculants out there comes from okra goo — it is completely non-toxic and cost-effective. In 2016, Japanese scientists also discovered a species of bacteria, Ideonella sakaiensis, that eats through a type of plastic called polyethylene terephthalate (PET) — notably, a prominent ingredient in Coca-Cola’s plastic bottles.
We have only started using plastic materials in the last 70 years and they have been advantageous for their easily moldable, light, durable and corrosion-resistant nature. But there are downsides: they take an extremely long time to degrade and they are toxic pollutants. They have become so abundant that they are now in the bodies of the general population, with potential long-term health consequences. Fortunately, we humans have always been resourceful and creative. We have tools at our disposal to remove and reduce plastics — all we have to do now is act.