Microplastics

It All Comes Out in the Wash

The most prevalent type of debris found in our waterways is plastic. One 2018 study estimated that there is anywhere from 15 to 51 trillion plastic particles in the ocean. That number is still growing, and quickly. Carried from land to the ocean by wind, streams, and rivers, plastics can then be transported by ocean currents around the globe. Once they reach our waterways, these particles can impact marine life.

Plastic can come in all shapes and sizes, but those that are less than five millimeters in length (the size of a sesame seed) are called “microplastics.” These tiny particles are chemically identical to their larger counterparts but are small enough to be ingested by marine life. Their surfaces attract pollution and other toxins and they never biodegrade.

Microplastics come from a variety of sources, including the now-banned microbeads that were found in toothpastes and facial cleansers as well as larger plastic debris that degrade into smaller and smaller pieces over time. These tiny particles easily pass through water filtration systems and end up in the ocean where they can impact marine ecosystems. Microplastics break down even further into nanoplastics (fragments less than 100 billionths of a meter). These pieces are so small they are invisible to the naked eye and can enter cells, tissues, and organs.

Recent research has identified another major source of microplastic pollution: synthetic fibers from our clothing. Polyester, nylon, acrylic, and other synthetic fibers — all forms of plastic — make up about 60% of our clothing worldwide. Synthetic plastic fibers are cheap and extremely versatile, providing for stretch, breathability, and warmth. These fabrics leach fibers into the environment both during their creation and with every trip through the washing machine. Estimates vary, but it’s possible that a single load of laundry could release hundreds of thousands of synthetic fibers into the water supply.

Data Activity

The Florida Microplastic Awareness Project (FMAP) is a citizen-science project affiliated with Florida Sea Grant. Volunteer citizens collect coastal water samples, filtering them and looking for microplastics. The data collected by volunteers are put into a Google Maps database to show the concentration of these particles visually.

In this exercise, students will examine FMAP data and graph them to compare the prevalence of natural particles vs microplastic particles. Please feel free to adjust the level of data manipulation based on your needs. Suggested levels are below.

Level 1: Download the pie charts included with the lesson and have students interpret the results and discuss the questions below.

Level 2. Provide students with the total counts included on the Teacher Data Summary and ask them to calculate percentages for each particle type to determine which is most prevalent. Then show them the pie charts and ask them to interpret the results and discuss the questions below.

Level 3. Download FMAP's raw data (Excel spreadsheet) and have students calculate totals for each column and percentages for each particle type. Graph the data, interpret the results, and discuss the questions below.

Discussion

• What type of microplastic was the most commonly seen?
• What percentage of the total was comprised by this debris item?
• What do you think the sources of these particles are?
• What can students do to reduce their contribution of these particles?

Extensions

VA SEA Lesson Plan - Trawling Through the 5 Gyres: A Microplastic Research Study
PBS Learning - Engineering for Good: Plastic Solutions
Oregon Sea Grant - Mitigating Microplastics