Microplastics 101: Everything You Need to Know
Quick Key Facts
- Plastic use has quadrupled over the last 30 years, and 380 million metric tons are now produced annually.
- Microplastics are small plastic fragments 5 mm or less in diameter, and are either created for products at this size or are the result of plastic degradation in the environment.
- Microplastics are found virtually everywhere on Earth, from the deepest parts of the ocean to the highest mountains, in the air we breathe and in the water we drink.
- Oceans are an area of particular concern regarding microplastics, as plastics degrade there more readily, and marine wildlife often mistake plastics for food.
- Heavy metals and environmental contaminants can stick to microplastics, which bioaccumulate in the tissues of animals that ingest them.
- Bottled water, seafood, dust, and even fruits and vegetables contain microplastics. Humans ingest roughly 50,000-120,000 pieces of plastic every year.
- Microplastics have been found in human blood, lungs, kidneys and placentas, where they can cause adverse health effects.
- New technologies are seeking to remove microplastics from environments using nanocoils and magnetic liquid.
We use a lot of plastic.
Since the 1950s, more than 8.3 billion tons of plastic has been produced by humans. All in all, only 9% of these plastics have actually been recycled, and the rest has either been incinerated or landed up in landfills — and, in many cases, in the natural environment, especially waterways and oceans. At our current rate of plastic production and disposal, our oceans are on track to contain more plastic than fish as soon as 2050.
Consider single-use plastic water bottles, for instance. One million of these plastic bottles are purchased every minute. So, what happens to all of this plastic? When we fail to dispose of it safely and it ends in natural environments, how do they change? Do they ever truly decompose?
What Are Microplastics?
No organisms can break down the chemical bonds in plastic. So when plastic waste ends up in the environment, it doesn’t degrade like paper, organic matter, textiles, or even aluminum, all of which can decompose eventually. In the presence of sun, heat, water, and mechanical forces from waves, winds and tides, plastics merely break down into smaller and smaller pieces. These tiny plastic fragments are called microplastics, and they’re found almost everywhere, from the most remote regions on Earth, to the food and water we consume, to the blood in our own bodies. Microplastics are defined as any plastic that’s 5 mm (about ⅕ of an inch) or smaller — sometimes so small they can’t be seen with the naked eye.
Where Do They Come From?
Microplastics are made of polyethylene (the material of most plastic bags and bottles), polystyrene, nylon, or PVC. They’re either created at that microplastic-size or are shed from larger plastic products over time as they degrade through exposure to heat, UV light, oxidation and mechanical processes. These two types of microplastics are categorized as either primary or secondary microplastics.
Primary microplastics were already less than 5 mm in size before they entered natural environments. Sometimes, these are resin pellets created to be melted down to make larger plastic products. Often, however, these primary microplastics are microbeads or textile fibers from synthetic fabrics, created purposefully for these products. Microbeads first appeared in personal care products about 50 years ago, according to the United National Environment Programme, and it’s very likely that you’ve encountered them before, whether you realized it or not. These tiny polyethylene beads are found in face scrubs, toothpaste, sunscreen, and makeup, and easily wash down drains and pass through treatment plants given their tiny size.
Microfibers are another ubiquitous type of primary microplastic. They look like thin strands of hair and are found in textiles like clothing, towels, and even cigarette butts. In the laundry, these fibers shed off of fabrics — as many as 700,000 per load — and contaminate wastewater. Fleece fabrics in particular are notorious for their shedding of plastic microfibers.
Secondary microplastics, on the other hand, were not created at these miniscule sizes, but rather come from larger plastics — plastic water bottles, plastic straws, plastic bags, tea bags, fishing nets, car tires, etc. — which degrade slowly into microplastics. Secondary microplastics account for two-thirds of all microplastics. They are created as large plastic products degrade in natural environments (like the ocean) over time, or are caused by run-off over land, which carries tiny fragments from landfills, road paints, tires, etc.
Microplastics can break into even smaller particles called nanoplastics — ranging in size from 1 nanometer (one-billionth of a meter) to 1 micrometer (one-millionth of a meter) — the effects of which are still being researched.
Environmental Impact of Microplastics
Although small, microplastics pose significant threats to the environment. Given their miniscule size, microplastics can travel far on the wind and water, reaching remote ecosystems, coating the floor of the ocean, and impacting wildlife along the way.
Where Are They Found?
Microplastics easily make their way into oceans and waterways, carried in the wastewater from our homes and industries, runoff from the land, or by wind and storms that bring plastic litter or microplastics into the ocean. They are found virtually everywhere on Earth: in the soil, the depths of the ocean and floating through the air. Microplastics have been uncovered in some of the remotest regions of the plant, including the Arctic and in freshly fallen snow in Antarctica. They’ve been found in the Mariana Trench — the deepest part of the ocean — and the summit of Mount Everest — the highest place on Earth.
Impact of Microplastics on Wildlife
We’ve all seen some version of the same photograph: a fish or wild animal cut open to show a stomach full of plastic, brightly colored waste where food should be. Extensive research has been done on the impact of plastics on wildlife, but information is still emerging about the impact of microplastics specifically. However, though they are small, we know that they do cause damage in ecosystems all over the world. On Lord Howe Island — a remote island of Australia — up to 90% of fleshfooted shearwater birds have at least one piece of plastic in their stomachs, showing just how far-reaching this problem is.
Most of the time, larger plastics and microplastics alike are mistaken as a food source by wildlife. When ingested, they are known to block the gastrointestinal tracts of fish and small birds, and can be abrasive to their digestive systems. There’s evidence to suggest that microplastics also cause a false sense of fullness in some animals, which might lead to decreased feeding and subsequent malnutrition. Microplastics can also interrupt nutrient absorption and impact an animal’s ability to reproduce, thereby affecting mortality rates and population growth.
Microplastics and Our Oceans
Eight million tons of plastics reach our oceans every year, which makes them an area of particular concern regarding microplastics. Imagine: that’s a garbage truck the size of New York City depositing waste in the ocean, every minute for a whole year. It’s thought that 14 million metric tons of microplastics are on the floor of the ocean alone, and in 2021, Kyushu University scientists estimated that 24.4 trillion microplastics are in the world’s upper oceans, which is equivalent to about 30 billion half-liter bottles.
Wind and runoff from waterways transports microplastics from land, and plastic also breaks down very quickly on beaches and in the ocean with heat, tides and wind aiding the degradation process. The top five trash items in the ocean — cigarette butts, plastic bottles, food wrappers, plastic bags, and straws/stirrers — degrade, as do the huge amounts of “ghost” (abandoned) fishing gear in oceans. There is evidence, too, that plastics increase ocean acidity, which could lead to coral bleaching and impact the development of molluscs.
Plastics are also vectors of heavy metals and environmental contaminants like PCBs and DDT. These pollutants can be found in low concentrations in the ocean, and easily latch onto the surfaces of microplastics, where they interact with one another and become more harmful. When aquatic wildlife mistake microplastics for food, these chemicals enter their body. As larger animals consume smaller ones, these chemicals bioaccumulate in their tissues over time, so predators at the top of the food chain are ingesting harmful amounts.
Microplastics and Human Health
New research has been emerging on the long-term health effects of microplastics on the human body, and it’s estimated that the average person ingests 50,000-120,000 pieces of plastic every year. In fact, we could each be eating as much as a credit card’s-worth of plastic every week.
How Are Microplastics Ingested?
Microplastics have become so widespread that they’ve been detected in the food we eat and water we drink — especially in bottled water, which is easily contaminated with microplastics through the manufacturing and packaging processes. Teabags release microplastics, too, when brewed in hot water — one study recorded as many as 11.6 billion microplastics and 3.1 billion nanoplastics released by a single tea bag during the brewing process.
Because fish often mistake microplastics for food, small species that are eaten whole (like shellfish) are a common vector of microplastics for humans. A recent study found that 75% of fish have ingested plastic in some capacity, and microplastics specifically have been found in 386 aquatic species, half of which are used commercially. Even fruits and vegetables can contain microplastics, absorbing incredibly tiny nanoplastics through their roots. Because microplastics and microfibers often mix with household dust, they can be ingested through the air, too.
Impact of Microplastics on the Body
All of these ingested microplastics can make their way into different areas of the human body. Some are even small enough to enter the bloodstream, confirmed by a groundbreaking 2022 study that found microplastics in human blood and 39 different microplastics in all regions of the lungs. Microplastics have even been detected in the human placenta for the first time, as well as the liver, spleen and kidneys.
Exposure to microplastics can disrupt the gut microbiome, damage DNA and affect human cells, causing allergic reactions and cell death. When inhaled, they can cause irritation, inflammation and even cancer. The harmful chemicals in plastics also impact the body, including endocrine disruptors like BPA and phthalates that impact hormone levels and can cause reproductive problems. Other chemicals like dyes and plasticizers leach out as the plastics break down. Of the 10,000 chemicals identified in plastics, 2,400 are of “potential concern,” and 88% can leach.
How to Avoid Microplastics
Luckily, there are simple steps you can take to cut microplastics out of your life, and help minimize their introduction into the environment.
- Cut out cosmetics and beauty products that contain microplastics.
Take a look at your current personal care products and beauty routine. You can determine whether a product has microbeads in it by looking at the ingredients. Polyethylene (PE), Polyethylene terephthalate (PET), Nylon (PA), Polypropylene (PP) and Polymethyl methacrylate (PMMA) are common ingredients in microbeads. Beat the Microbead’s search tool also helps you uncover the plastic content of common personal care products like lotion, toothpaste, face wash, soap, makeup, sunscreen, lip balm, perfume and more.
- Don’t microwave food in plastic.
When heated, some plastics will leach out BPA and phthalates into the food you’re about to eat. Transfer leftovers or takeout onto plates instead of heating them right in the container. Paper takeaway cups are similar, and release microplastics when hot liquids are poured into them. When grabbing a coffee on the go, try using a reusable, insulated thermos instead.
- Drink tap water instead of bottled water.
A 2018 study found that bottled water has double the amount of microplastics as tap water, so avoid it whenever possible (plus, single-use bottles are a huge source of waste). Tap water can contain microplastics, too. Filter your tap water at home with a carbon block or distillation filter, which are proven to filter out microplastics.
- Switch up your laundry routine.
With each load of laundry, your clothes are likely shedding microfibers — possibly hundreds of thousands per wash. A 2017 report found that 35% of all ocean microplastics originate from synthetic fabrics, but you can prevent these fibers from entering wastewater in the first place. Install microfiber filters in your washing machine, or wash your clothing inside a Guppyfriend bag, which traps fibers inside. The Cora Ball is similar, and keeps fibers from breaking off of clothes in the first place. The tumbling action of dryers also allows clothing to shed fibers more readily, so air-dry whenever possible.
- Clean regularly.
Since microplastics are often in dust particles, keeping your space clean will minimize the threat of inhaling microplastics — especially if you have small children that crawl or play on the ground.
- Cut down on single-use plastics.
Simply put, the fewer plastics we consume, the fewer microplastics will end up in our natural environment. Each year, 335 million metric tons of plastic are created, 50% of which consists of single-use products. Consider the single-use, disposable items you use regularly — coffee cups, water bottles, plastic storage bags, heavily-wrapped produce — and whether they can be replaced with reusable alternatives.
What Can We Do?
Personal actions — like reducing use of single-use plastics — are important, but in order to truly get microplastics under control, legislative and technological solutions are paramount.
The Microbead-Free Waters Act of 2015 was signed by President Obama, and prohibits the manufacturing and distribution of rinse-off cosmetics that contain microbeads. The UK released a similar ban on microbeads in personal care products and cosmetics in 2018. However, further legislative action targeting both plastics and microplastics specifically will be necessary to reduce their introduction into the natural environment.
New technological innovations, however, seek to remove microplastics from the environment after they’ve been introduced. Scientists are using nanocoils — an emerging hybrid material that acts as a small reactor — to break down microplastics into smaller pieces, then eventually into water and carbon dioxide. They hypothesize that this technology could be used on wastewater, too, before it flows into the environment, catching microplastics before they move out to sea. Researchers at the Royal Melbourne Institute of Technology have also discovered a way to use magnets to remove microplastics from water. They’ve developed an absorbent that, when mixed with water, is attractive to microplastics (and even some environmental pollutants). Because of the iron content of the absorbent, magnets can be used to collect it and the microplastics afterwards. These scientists believe this technology could be a viable, affordable alternative to existing technology, which cannot filter out microplastics smaller than 5 mm.
The issue of microplastics is complex, and one that’s wrapped up in many other social and environmental concerns: our huge use of plastics (contingent upon consumerism and dependence on disposable items), our flawed systems of recycling and waste disposal, and lack of adequate regulation around plastics. A reduction in single-use plastics, better removal technologies, and legislative action around plastic production and disposal are needed to reduce microplastics for the sake of human and environmental health.
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