Microplastics, as indicated by their name, are tiny bits of plastic that measure less than five millimeters in diameter. That’s about the size of a small green pea! According to The Ocean Cleanup, approximately 1.2 million tons of microplastic waste are generated each year, and 1/5th of that global statistic comes from North America alone.

Primary microplastics are often manufactured for consumer products such as cosmetics, specialty soaps, clothing, and other textiles. Because plastics are prone to physically breakdown, microplastics may also form as larger debris breakdown. The road markings indicating lane separations, glossy coating all over the hull of a boat, and abandoned rubber tires are all possible sources of these secondary microplastics. 

Just last month, one study documented the highest concentrations of microplastics ever recorded within deep-sea ocean sediments: 1.9 million microplastic pieces per square meter!

The scientists were examining sediment samples from the depths of the Tyrrhenian Sea to investigate the role of deep ocean currents in microplastic transport and deposition, and all 16 of their sediment core samples were found to contain microplastic particles.

According to the Society of Environmental Toxicology and Chemistry, littering and landfill discharge are the main pathways whereby plastics enter our rivers and oceans. The density of plastic marine debris accumulated determines if plastic waste remains on the surface, becomes beached in coastal areas and estuaries, or sinks to deep-sea sediments.

As we strive to reduce plastic consumption and adopt more responsible waste management practices, it is important to address the potential impacts of microplastic movement in our oceans. Ocean circulation patterns are formed by global trade winds and forces created by the Earth’s rotation. Wind and wave patterns are essential for the temperature regulation and maintenance of healthy nutrient flow for marine organisms.

Weather conditions and ocean circulation play a significant role in the geographic distribution of microplastics. Circular ocean currents can relocate plastic marine debris from remote sources to more stationary and centralized accumulation sites called “gyres.”

Disproportionately large amounts of marine debris have been found in these areas, including the North Atlantic and Great Pacific garbage patches.

Studies have also consistently indicated that microplastics are unintentionally consumed by marine organisms. Scholars highlight the ingestion of microplastics by species marked for human consumption and the infiltration of micro- and (even smaller) nanoplastics in filtered drinking water. This is a widespread problem because most standard water treatment facilities do not effectively remove all microplastics.

Additional risks are posed by the chemical composition of microplastics. While plastics are produced, hundreds of chemical additives are used to enhance their unique characteristics. These chemicals may leach out from waste products into our waterways, disrupting the chemical composition of natural sea water while posing risks to plants and animals reliant on marine ecosystems. Studies on the biological and biochemical impacts of plastic pollution have only scratched the surface of potential effects that these materials could have over the long-term. This knowledge gap is particularly problematic for coastal and/or environmental justice communities that are more likely to be exposed to polluted waterways, contaminated drinking water, or affected marine life.

Even though microplastics have been a problematic by-product of solid waste for decades, they represent a relatively new area of multidisciplinary study. Scientists have investigated the fate of plastic marine debris in the context of the life cycle of plastics, finding that plastic cannot be chemically broken down on its own overtime. Plastic waste, instead, only physically decomposes from macro- to micro- to nano-plastics over hundreds of years.

Polymer scientists have sought to identify new possibilities for recycling plastics, including macroplastics, collected from the depths of our oceans. This has been a challenge because there are a number of unique plastic polymers used to produce the highly durable products that we use and discard. Two large areas of focus have been optimizing methodology to increase the amount of times that plastic materials can be recycled and finding new ways to transition existing materials for very different applications than their original form. One example of an area for growth is demand for composite materials made from fiberglass and carbon fibers. Engineers use these materials for building automobile and wind turbine frames. It would be ideal to satisfy their needs using reprocessed plastics, but that would require complex logistics and technology that is not yet efficiently coordinated.

“Plastics recycling with a difference” [Science Magazine]

For now, it’s best for us to stay committed to recycling efforts, strive for circularity by reusing and re-purposing materials we already own, advocate for responsible waste management within our communities, and direct advocacy efforts to hold businesses accountable for their actions. We can also seek out products that do not contain primary plastics, such as natural soaps and scrubs without microbeads, and brands that prioritize circularity by including recycled materials in their supply chain. If you crave that scrubby sensation from skincare products, try making your own with coconut oil and sugar or salt as the base ingredients. There are loads of ingenious fragrance combinations out there using essential oils that may be extracted from herbs or fruits you already have at home. In the end, it’ll have the same satisfying and nourishing effect, without negative environmental impacts!

In this graphic, projections indicate that we’ll have produced 26 billion tons of plastic waste by 2050. Primary waste refers to plastic becoming waste for the first time. So, that value doesn’t include waste from plastic that has been recycled. [G. Grullón, Science]

You may have already seen pictures in the news and throughout social media much like this decomposing albatross with a stomach full of plastic waste.

These incidents are often caused by the plastics we use and discard on land. Plastic litter is a more common problem in wealthy, industrialized countries like the US and UK. Although we have the systems and resources to manage large streams of collected waste, our access to limitless single-use products and the other conveniences have brought us out of touch with the value of the materials we discard and the immediate effects of tossing them as litter. Although our waste management systems are not flawless, following common sense standards for disposal is tremendously better than leaving trash behind in an unintended spot.

[Dan Clark, US Fish and Wildlife Service]

No matter how they find their way into the environment, macro-plastics can be easily mistaken by marine life for food.

The jellyfish-like movement of a drifting plastic bag may come to mind, but this problem isn’t limited to physical appearances. A recent study conducted at the University of North Carolina at Chapel Hill found that sea turtles responded most similarly to the smell of “biofouled” plastics as to that of their own food. This finding suggests that the unavoidable accumulation of microbes, algae, plants and small animals on the surface of plastic marine debris makes it more enticing for turtles to eat our trash.

Scientists estimate that nearly all seabirds and over half of our oceans’ sea turtles have ingested plastic. This blocks their digestive tracts and diminishes their appetite, resulting in malnutrition and population decline.

Fragments of plastic bags found in a juvenile green turtle’s stomach.[Victoria Gonzalez Carman, Business Insider]

Macro-plastics cannot chemically degrade, but they do physically breakdown into microplastic bits that are difficult to see or filter out of the water. Those tiny bits contaminate our drinking water and accumulate in seafood when consumed by fish. Even more often than macro-plastics, these tiny bits of microplastics are unintentionally consumed by marine and freshwater species.

Once ingested, microplastics break down into even teenier nano-plastics that can penetrate cell membranes⁠. This causes severe inflammation, breakage and decay of tissues in the gastrointestinal tract, absorption of harmful chemical additives, and often a stimulus response to toxicity. According to one study on the effects of nano-plastics, exposed fish exhibited severely altered feeding and shoaling behavior and metabolic function.

How does this affect human health?

Researchers from the University of California Davis and University of Hasanuddin found plastic debris in the majority of fish species sampled during their studies, all of which were marketed for human consumption. Notably, different streams of waste affected the two regions: textile fibers were found in 67% of species living off of the West coast of the US while larger microplastic debris were found in 55% of the species tested from Indonesia.

If the issue goes beyond marine species, into our drinking water and uptake by plant nutrients, how can we protect our health and address this issue over the long-term?

Survey your day-to-day activities and gradually phase out the non-essential single-use plastic products. Reducing your individual plastic consumption and opting for reusable or biodegradable alternatives will set an example for your family, friends, peers, and coworkers that’ll create a ripple effect of positive impact. When we all become stronger advocates for responsible consumption, we start to create shifts in social norms that can affect producers’ activities.

Odds are, you already have loads of plastic products at home. Don’t just throw them away! Refill, reuse, and repurpose the items you’ve already purchased or received as packaging. You will maximize utility to continue enjoying the durability of plastics while reducing your demand on new products/materials.

Advocate for responsible disposal and management of plastic waste in your home, at school, at work, at businesses you frequent, and to your local government. Spread the “trash talk” by sharing your knowledge to support a waste-conscious culture. In the United States, most of us enjoy the privilege of not seeing where the items that we throw “away” end up. That means we are all that much more responsible for learning about how we can be more proactive in reducing the waste we create and holding large polluting corporations accountable for their impacts.

Support or engage in research on the environmental and biochemical effects of plastic production, plastic consumption and use, or plastic waste. Simply sharing the results of intriguing new studies on social media can help to spread word on important findings!