Educational Resources Lets Talk Science Challenge participants

Straws are a common single-use plastic. Image © Andreas Steidlinger,

Straws are a common single-use plastic. Image © Andreas Steidlinger,

STEM in Context

We Use a Lot of Plastic

Mira Okshevsky


What are microplastics? How are plastics polluting aquatic ecosystems?

Are you using a mouse right now? Did you brush your teeth today? Are you wearing clothes?

If you answered yes to any of those questions, you have definitely been in contact with plastic today. Many of the things you use every day are made of plastic, including toothbrushes, keyboards, headphones, pens, and even your clothing! (Check your labels - materials like polyester and nylon are made from plastic.)

Plastic is a popular material because it’s strong, light, and cheap to make. But the fact that plastic is so durable is not such a good thing once we’ve finished using it. That’s because plastic takes a very long time to break down in the environment. Wind and water carry plastic garbage to the oceans, where ocean currents cause it to collect in gigantic patches of garbage. Scientists estimated that 8 million tonnes of plastic entered the oceans in 2010.

Did you know?

According to a 2016 report, by the year 2050, the oceans will contain more plastic than fish!

Some of the effects of all this plastic waste are easy to see. Beaches are becoming covered in plastic garbage. Birds and other marine animals get tangled up in plastic garbage, become strangled by it and drown. Whales confuse plastic floating in the water for food.

For a whale, a belly full of plastic can damage their organs and lead to starvation.

But plastic garbage, and its effects on the environment, are not always visible.

What are microplastics?

In the oceans, waves and sun break down plastic into smaller and smaller pieces. Microplastics are pieces of plastic smaller than 5mm, which is about the size of a sesame seed. This includes particles that are so small, they cannot be seen by the unaided human eye.

Microplastics are everywhere! Scientists have found them not only in the ocean, but in our tap water, in the soil that our food grows in, and even in the remote Arctic. Microplastics can be found in fish and shellfish that we eat, in beer, and in the air. A Canadian study even found them in bottled water.

Microbeads in toothpaste
Microbeads in toothpaste (Pexels )

Where do microplastics come from?

Sometimes microplastic is intentionally added to the products we use. For example, small round plastic pieces called microbeads are added to some toothpastes and bath and body products, to act as exfoliants. These plastic microbeads have now been banned in some countries, including Canada.

But microbeads are only a drop in the bucket of all of the microplastics contaminating our environment. Most microplastics break off of larger pieces of plastic garbage when exposed to wind, waves, sunlight and/or microbes in the environment. Also, some of the microplastics found in nature are actually microscopic fibres such as nylon or polyester. They are shed by our clothes when we wash them. These fibres are often too small to be removed in wastewater treatment plants. Instead, they can end up in the oceans.

Once in the oceans, these microplastics can be swallowed by the organisms that live there. Since scientists are only beginning to research this topic, they are not sure exactly what the effects of this are. Some studies have shown that microplastics can be toxic to organisms who eat them, in part because toxic substances can stick to them. In other studies, the results are less clear. Scientists are researching this topic at this very moment.

What are the effects of microplastic on human health?

With microplastics in our drinking water, in our food, and in the air we breathe, should we be alarmed? The short answer is, we don’t know. In the short term we are probably safe enough. There have not been any scientific studies confirming any risk to human health from microplastics in the environment. But scientists need to do more research on this topic. One issue that we can’t deny is that microplastics are a lot harder to clean up than the larger plastic items they form from. It is easy to pick up a water bottle from the beach. But it’s not so easy once it has broken down into a thousand pieces.

How can you help?

There are two big ways that your own actions can decrease the amount of plastic garbage that enters the environment. First, cut single-use plastic out of your life! Use reusable containers to bring your lunch to school and carry a reusable water bottle. Bring your own bags to the grocery store, and ask for your drink without a plastic straw.

The second thing you can do is to make sure you recycle the plastic you do throw away. Around the world, only 9% of plastic is recycled. In Canada, only 11% of plastic is recycled. We can do better than that!

Starting Points

Connecting and Relating
  • What plastic items have you used today? Could you get along without them? Explain.
  • Have you ever used a product with microbeads in it that you know of? Would you have used that product if you knew in contained microplastics? Explain.
  • Do you always recycle single-use plastic items, like drinks cups and plastic cutlery? Why/why not?
  • Where have you noticed plastic wastes in the natural environment? How did they get there?
Relating Science and Technology to Society and the Environment
  • Should governments enforce a reduction in the production of plastics? Why/why not? 
  • What measures could be taken nationally, provincially and locally to reduce the amount of plastics that end up in the environment? 
  • Why is clothing waste becoming a problem globally?
Exploring Concepts
  • How do microplastics end up in the oceans? What are the sources of microplastics?
  • What foodstuffs can microplastics be found in? 
  • What is the difference between particle toxicity and chemical toxicity of microplastics? 
  • Research the methods that are being used to help remove microplastics from ocean waters. (Note: This question will require additional research)
Nature of Science/Nature of Technology
  • Design an investigation to study how long it takes a variety of fabrics to decompose and/or degrade in soil or sand.
  • The application of science and technology created and developed the many plastics we use in the world today. Can science and technology also solve the global plastics pollution problem? Why/why not? Explain.
Media Literacy
  • Compare the promotion and vision for plastics in the 1950s with its promotion and perception in the world today.
Teaching Suggestions

  • This article, and the connecting resources, can be used to examine human impacts on natural ecosystems, such as the impact of the widespread use of plastics on aquatic and terrestrial environments. This article is good for introducing the concept of microplastics.
  • This article, along with the video, Ocean Confetti (Video – 2:57 min.), can also be useful to help students deepen their understanding of the sources and impacts of microplastics in the environment. After viewing the video students could also conduct a survey of products they have a home to determine if any of them contain microbeads (i.e., the ingredient polyethylene).
  • After reading and viewing teachers could have students complete a Silent Discussion / Graffiti learning strategy (in groups or as a class) to help them collectively think about/brainstorm actions that would help reduce the amount of single-use and other plastics they use in their daily lives. 
  • Download ready-to-use reproducibles using the Silent Discussion / Graffiti learning strategy for this article in [Google doc] and [.pdf] formats. 

Learn more

Plastics and Sustainability: A Valuation of Environmental Benefits, Costs, and Opportunities for Continuous Improvement This 2016 plastics industry-commissioned report concludes plastics are more environmentally damaging per tonne than alternatives. However, they are less damaging overall because alternatives tend to be a lot heavier.

One way to reduce plastic pollution is burning it (which would also generate energy), according to the CBC. However, this would cost twice as much as dumping it does.


Barnes, D., Galgani, F., Thompson, R., & Barlaz, M. (2009). Accumulation and fragmentation of plastic debris in global environments. Philosophical Transactions Of The Royal Society B: Biological Sciences, 364(1526), 1985-1998. doi: 10.1098/rstb.2008.0205 (paywalled)

Kalogerakis, N., Karkanorachaki, K., Kalogerakis, G., Triantafyllidi, E., Gotsis, A., Partsinevelos, P., & Fava, F. (2017). Microplastics Generation: Onset of Fragmentation of Polyethylene Films in Marine Environment Mesocosms. Frontiers In Marine Science, 4. doi: 10.3389/fmars.2017.00084

Peeken, I., Primpke, S., Beyer, B., Gütermann, J., Katlein, C., Krumpen, T., ... & Gerdts, G. (2018). Arctic sea ice is an important temporal sink and means of transport for microplastic. Nature communications, 9(1), 1505.

Rochman, C. M., Tahir, A., Williams, S. L., Baxa, D. V., Lam, R., Miller, J. T., ... & Teh, S. J. (2015). Anthropogenic debris in seafood: Plastic debris and fibers from textiles in fish and bivalves sold for human consumption. Scientific reports, 5, 14340.