Understanding Microplastics in waterways: where are they found, what are the sources, and what can be done?

By James Richards and Jack Sullivan

James and Jack explain microplastics

What are microplastics?

Some plastics are meant to be small. An example of these are the microbeads you see in your hand sanitizer, beauty products, or any “rinse-off” cosmetic including shampoo and toothpaste. Microplastics are considered to be any plastic less than 5 millimeters big and they can be fibers, fragments, or gel-like structures (such as the ones used in personal care products). Microplastics can be found in sediment, soils, water columns, arctic sea ice, mountain tops, sea trenches, and this could be bad for the environment because it affects our food sources, contaminates our drinkable water, and it’s foreign components most likely shouldn’t be found in our bodies. Studies to how dangerous these microplastics are to us is limited.

Microplastics can come from the Macroplastics that are found in the ocean, highways, etc. These macroplastics can be seen with the human eye. But degradation of plastics in the environment does not break down littered plastics as fast as plastic in the industry is being produced.

How does the microplastic get there?

Bar chart of sources and fate of microplastics in the European Union

Sources of these outcomes can come from homes, factories, farms, or fishing sites. This pollution doesn’t have to start as microplastic as well, this is how the degradation processes contribute to getting the plastic out of the waterways even harder.

Types of Degradation

  • Solar UV Radiation ⇛ Photodegradation

  • Oxidation ⇝ Thermal Oxidation

  • Water Abrasion ↝ Reactions with H2O that Catalyzes Hydrolysis

  • (Or the actions of microorganisms which start Biodegradation)

What does this mean for us?

Possible toxicity being implemented in the environments that we extract our valuable resources from brings that toxicity in our lives. Microplastics can be eaten by fish in the sea and we can eat that fish, and as simple as that, plastic is in our bodies. The reason we say possible toxicity is because the uncertainty of how much damage these microplastics affect the human body are still in the air. Additives in the polymer can definitely determine what kind of danger you are in though. A recent study conducted by Prof Dick Vethaak, an ecotoxicologist at Vrije Universiteit Amsterdam in the Netherlands, on health concerns from plastic said, “But we have to extend the research and increase the sample sizes, the number of polymers assessed, etc. It is certainly reasonable to be concerned” (Vethaak 2022). The economy can also be looped into this problem with the fact that there’s an estimated cost of 13 billion dollars of plastic pollution annually.

PROs

Microplastics can be used in a variety of cleaning agents, from beauty scrub to toothpaste. The tiny nature of the plastics is mainly used where rigid abrasives are needed but large instruments will not fit. Thankfully, the necessity of such a small hard object is minute and easily replaced with better biodegradable solutions.

CONs

Microplastics are small, by definition they are 5mm or smaller. This means that many of the world's countries' sorting and filtration systems miss them. Inevitably that leads to microplastics leaking into places they aren't meant to go. The oceans are a prime example of this, with 40 percent of the world's ocean surfaces covered. This is due to the nature of the world's landfills and the availability of correct disposal to poor countries. Landfills do not provide a consistent barrier for near microscopic plastics during rain or wind storms, particles are then carried to the oceans or back into cities.

Real World Problems

Poll of California ranking beach cleanliness as important factor

However, even if all the cities in countries that could afford a complex processing plant for these microplastics there would still be leakage from less fortunate countries. “In the Maldives, a developing nation that lacks much local manufacturing, a single tourist produces almost twice as much trash per day as a resident of the capital city. Consequently, the tiny island nation was ranked last year as the world’s fourth largest producer per capita of mismanaged waste.” writes Laura Parker, a NatGeo researcher. This shows that countries that rely on tourism that are still developing will usually have more waste than they are able to process.

What is being done about this?

Many laws have been passed that ban the interaction of microbeads and our waterways, an example of a bill that passed was the ‘‘Microbead-Free Waters Act of 2015.’’ This act amended the FDA and Cosmetic Act to prohibit the manufacturing, delivery, and selling of rinse off products with intentionally-added microplastic additives such as microbeads.

Ocean Friendly Alternatives to these products are being made already. For example:

Scale of nano and microplastics compared to other objects