Microplastics: Big Impact, Little Particle
Single-use plastics are the worst. There, I said it and I'm not taking it back. Look no further than the Great Pacific Garbage Patch (which is now three times the size of France), the horrible environmental and human health impacts of incinerating plastic waste, or the fact that even after more than 110 years of using plastic, we still haven't figured out how to recycle it effectively. But, while we've all seen a plastic bag tumbleweed across a grocery store parking lot, there are other plastics that you and I have never seen with the naked eye... and they could be impacting you, me, and the environment in ways we never saw coming.
First, let's take a huge step back to the early 1900s, when a brilliant scientist named Leo Baekeland created the first mass-produced synthetic plastic, which he called 'Bakelite'. Ignoring the fact that the name 'Bakelite' is a real stinker, this invention was the first step in the creation of plastics like PVC, polystyrene (aka Styrofoam), and nylon throughout the 20s and 30s. After a few decades as a luxury good, plastics became a hit because of how easy they are to make, how strong they are, and how well they form into shapes. As a result of these benefits, advancing technology, and some questionable tactics by oil producers and soft drink companies, plastic production has increased to nearly 350 million metric tonnes per year.
To put that in perspective, that is the same weight as 70 million elephants, 950 Empire State buildings, 250 million 2011 Toyota Priuses, or (no joke) 9 billion humans.
You heard that right, we produce more plastic per year than the combined weight of every human on earth, and then some. And, production isn't slowing down anytime soon. Market research firm Grand View Research recently released a report projecting that the market for plastics will go up by more than 25% over the next 7 years, and by the year 2050, ocean plastics will literally outweigh all fish. Of course, there has been a push towards using more biodegradable plastics, but that also comes with quite a few issues. Biodegradable plastics also only make up a little more than 1% of all plastics in production, which means the technology is not yet scalable to meet the increasing plastic demand by itself. Plus, those bio-'degradable' plastics don't actually naturally degrade in any reasonable timeframe (See our recent blog post about this exact topic).
We all think we have a pretty good idea of what kinds of plastics end up in the oceans, and we tend to blame single-use plastics like water bottles, fishing nets, and plastic bags, for good reason. And, as we all remember from earth science class, those plastics won't degrade for hundreds or thousands of years... right?
Enter microplastics, the latest scourge on the planet, more than 100 years in the making. Microplastics are exactly what they sound like: incredibly small threads and particles of plastic. Well, if we want to get technical about it, they are actually any plastic particle less than 5 millimeters in size (which isn't even 'micro' ... it's 'milli'). And, since we are splitting hairs on the terminology, they can even drop down into the nanoscale (roughly 10,000 to 100,000 times smaller than one of your hairs, or about the size of a virus)which presents a whole ânother set of not so little issues. So why haven't you heard much about these micro- and nanoplastics? While small plastics in the environment were first discovered by scientists back in the 1970s, it wasn't until the last 5-10 years that microplastics finally got the attention they deserved from the scientific community, and as a result, there is still so much to learn about them.
TIME TO PUT A MICROSCOPE ON MICROPLASTIC
Microplastics are generally split into one of two groups: primary and secondary microplastics. Secondary microplastics are produced when bigger plastics, such as plastic bags or plastic water bottles, degrade over time after being released to the environment. They enter the ocean and slowly break down due to radiation from the sun, scratching up against hard surfaces, and changes in temperature. Recent studies in the journal, Scientific Reports, have noted that many of the secondary microplastics we see in the ocean today are from plastics that entered the ocean in the 1990s and earlier, meaning that these single-use items only need a few decades to degrade into microplastics. In fact, some of those early plastics developed by Leo Baekeland and other chemists all those years ago are likely microplastics right now. So much for plastic junk not degrading for thousands of years, huh? Heck, a hot-off-the press study from the Water Research journal has found that even bio-based and biodegradable plastics that enter freshwater and seawater can break down into secondary microplastics, and can potentially have the same bad impacts. Seems like no large plastics are really that safe...
Meanwhile, primary microplastics are those that are released into the environment in their already tiny form. Some of these releases happen by design. For example, if you've ever used soap, cosmetics, or exfoliants with microbeads in them, you've used a product that had microplastics in it by design. Of course, these things are meant to eventually be washed off, so when you finish your day over your sink or in the shower, those microbeads go down your drain to your local wastewater treatment plant. While wastewater treatment plants are pretty good at removing most pollutants (stay tuned for a super nerdy blog post on this coming soon!), they weren't really designed to handle plastics, especially at the micro- or nano-scale. As a result, some microbeads and microplastics will get through and be dumped into lakes, rivers, or the ocean along with the treated water. Fortunately, over the last few years,the US, the EU, Canada, and others have banned the production of personal care products and cosmetics that contain microbeads.Unfortunately, personal care isn't the only home of these micros, so that action alone hasn't completely eliminated primary microplastics.
A groundbreaking 2018report from the International Union for the Conservation of Nature noted that roughly 8 million tonnes (or 322 billion plastic grocery bags' worth) of primary microplastics are entering our oceans every single year, and the vast majority are not from your makeup. More than 60% of those microplastics actually come directly from our clothes and our cars. Now, you are probably wondering how your favorite hoodie and my 2011 Toyota Prius are contributing to microplastics in the ocean. (That's right, I drive an old Prius, and it is still totally silent under 5 mph, just like in that episode ofThe Office when Andy runs over Dwight.) I'll first answer with one word: 'abrasion.' Now I'll answer with a lot more words the way a typical scientist would: When you wash your clothes, especially those with nylon, polyester, or other synthetic fibers, those fibers scrape against each other and the walls of the washing machine and break off as microplastics. And like we said before, wastewater treatment can't catch them all, so some of those plastics will make their way to the ocean. Same story with cars -- as you drive, the rubber and plastic in your wheels degrades as it makes contact with the roads. When it rains or gets really windy, those particles are picked up and eventually find their way into the ocean. The thought of it just drives me crazy.
Can tiny pieces of plastic really be all that bad, especially when compared to those bigger plastic objects we hear about more often?While we haven't seen any major scientific agreements on how significant the impact of microplastics can be on the environment, we do know that they can be at least somewhat harmful to humans, plants, and animals. For example, a 2019 study looked at the impacts of the microplastic version of polypropylene (the plastic on bottle caps, certain packaging, and in some cold weather gear and sportswear) on human cells. The authors found that these materials can be harmful to cells in three distinct ways:
- Due to their small size, microplastics can physically enter the bloodstream, and if they get small enough, they can even penetrate and enter the cells in your body.
- Plastics can carry and release nasty chemicals like BPA and brominated flame retardants, which can act as endocrine disruptors. These chemicals could do damage to hormone levels, child development, and your body's immune response. When those plastics become microplastics, it gets easier for them to enter your body, increasing your exposure to those chemicals.
- Microplastics are kind of like my college dorm room and my super stylish 2011 Toyota Prius... covered in germs. That's right, microplastics can act as a miniature breeding ground for germs, providing them with a comfortable place to grow and multiply until they finally get swallowed into your body and make you sick.
Here is the worst part: there are very few places left on earth that are untouched by microplastics. Last year, researchers found microplastics at the highest point on Earth, at the top of Mount Everest. Two years before that, thousands and thousands of microplastic pieces were found in a single liter of water from the deepest point on Earth, the Mariana Trench. On top of that, every aquatic animal is being affected. A study in 2019 in the UK looked at 50 stranded porpoises and dolphins and found that all 50 had detectable levels of microplastics somewhere in their bodies. Studies have also found significant levels of microplastics in fish, birds, and ocean plants, meaning they are finding their way into our food. In fact, we likely eat and drink more than 50,000 microplastic particles a year. No wonder that salmon dinner last week tasted like a shoe. And it all culminates in a research article in the journal Environment International from earlier this year, where researchers recorded the first evidence of microplastics in a human placenta. That's right, microplastics are so pervasive in the world that there is a chance they are being transferred to humans before they are even born.
I feel like I just unloaded a bunch of doom and gloom onto you, but instead of leaving you worried, I want to (Saran) wrap this up with some positivity. There is hope on the horizon! A 2020 review in Environment International found that 39 technologies have emerged over the last 15 years or so that are aimed at either capturing primary and secondary microplastics before they reach you, or preventing the release of primary microplastics in the first place. Scientists have also been ramping up efforts to better understand how to remove microplastics from drinking water supplies through new treatment techniques and technologies. Meanwhile, groups at MIT and other leading institutions are working to better understand how natural processes like sunlight can be used to degrade plastics into less harmful substances. Most importantly, scientists are working to understand how microplastics are generated inthe first place, and how people like you can lower the number of microplastics they release.
WHAT CAN YOU DO TO HELP?
That's right, microplastic pollution is yet another problem that needs to be tackled by all of us, not just the folks in the laboratory. Here are a few tips and tricks from recent research that you can use:
Use fewer single-use plastics. Just consider that a rule from now on for, like, every reason imaginable. Climate, waste, water, microplastics, health... all of it. Single-use plastics are the worst, and buying one reusable item and using it forever is almost always the better choice. (Check out our blog post on the Sustainability Paradox to better understand why we used the word 'almost')
Don't buy synthetic clothes when you can help it! Microplastics come from polymer-based materials like polyester and nylon, not natural fibers like cotton or hemp. Even when cotton and hemp release microfibers, they break down in the environment really quickly. When buying your next sweatshirt, reach for the natural fiber instead of the synthetic one.
Since most textile-based microfibers are released during the wash cycle, try to wash your clothes on the Delicate Cycle. A 2020 Italian study found that rougher settings can increase abrasion and lead to more particle release. However, when the Delicate Cycle was used instead of the Cotton Cycle, particle release dropped by more than 20%.
If you have your own washing machine (or you can be ultra-sneaky in your apartment building's communal laundry room), consider installing a microfiber filter, which is designed to capture microplastics released during the wash cycle. Research proves these things can lower the total number of microfibers released from each wash cycle. If you don't feel handy enough to install a filter, there are also options that you can throw into your washing machine to collect microfibers during each wash cycle, like this or this.
If synthetic fabrics are completely unavoidable, try to buy the fabric textures and types that release fewer, larger microfibers. Those are found in the figure below, based on a 2020 study in Environmental Science and Technology. Obviously, we want to release fewer microplastics into the environment, and larger particles are usually less toxic to wildlife and more likely to be caught by wastewater treatment technologies. Aim to buy and use the fabric textures closer to the top left of the chart, and really try to avoid microfibers when you can.
We spent a lot of time talking about clothing, but as mentioned above, cars release microplastics too! When possible, walk instead of driving, to limit wear and tear on your tires. When you do drive, make sure to keep your tires properly inflated to prevent excess tire wear (and improve your gas mileage), and regularly rotate your tires so they wear down more evenly and more gradually.
Avoid single-use plastic water bottles at all costs. They obviously release secondary microplastics after floating around in the water for a while, and a 2018 study in Frontiers in Chemistry found that 93% of plastic water brands that were tested had detectable levels of microplastics in the water. Also, those same authors let us know that there were twice as many microplastic particles in bottled water compared to tap water or beer. I don't want to put words in Dr. Mason's mouth, but it sounds like she basically said that beer is better for you than bottled water...
Consider lowering your seafood-based diet. While ingesting microplastics in water is going to happen no matter what, about half of the average person's plastic microparticle ingestion comes from eating seafood via biomagnification (or the concentrated buildup of toxins, chemicals, or microplastics in the food chain).
Consider buying a super cool, super rad, state-of-the-art 2011 Toyota Prius. It has nothing to do with microplastics, but it drives like a dream and I think this is information worth sharing.
Finally, don't panic! The science on microplastics is still pretty new, and we are all figuring out how to best deal with it. While you might be scared to drink water now, know that the health benefits (for example, surviving...), far outweigh the known risks from microplastics.