Microplastics Case Study — The Smaller Picture, Part 1

Microplastics 101

Plastic is ubiquitous. Because of its versatile properties, plastic is used in all aspects of modern life – clothes, electronics, packaging, car tires — to name just a few. Most plastics are not biodegradable, some are comprised of harmful elements or organic compounds, such as lead, thallium, and per- and polyfluoroalkyl substances. When not disposed of properly these compounds remain in our environment for a long time as persistent pollutants. Over time plastics break down into smaller plastics, known as secondary microplastics.

Microplastics are defined as plastic particles measuring <5 mm and are categorized into two groups: secondary microplastics — plastic particles created by unintentional breakdown processes of larger plastic particle; and primary microplastics — plastic particles intentionally engineered to fall within this size range.

The Big Picture

The environmental presence of and human exposure to microplastics are igniting curiosity and stirring up questions about their presence and potential impacts. How do they impact human and animal health? How do they impact environmental health? What are the exposure routes of microplastics? How can we detect microplastics? How can we ensure a healthier, and safer world?

Case Study

To better understand the presence of microplastics in a real-world context, McCrone Associates performed a rinse study analysis to screen for particulate from post-cycle laundry wastewater captured from a household washing machine. Flow imaging microscopy (FIM) analysis was used to visualize and quantify particulate suspended in approximately 2 mL of laundry wastewater. The FIM optical system captured real-time images of the particles in the fluid with a resulting count totaling 269,669 particles. The software automatically identified different particle types based on pattern recognition and categorized the particles into groups: fiber-like, protein-like, unclassified, and sub-5 µm.

Are these particles microplastic? Or general environmental contaminants? Now that we know there is something there, we need to determine what is there. Stay tuned for Part 2 of “Microplastics Case Study — The Smaller Picture” to learn how we isolated, characterized, and identified the different particle types.

See Figure 1 for wastewater classification results showing particle groups and particle measurements. See Figures 2 through 5 for micrographs of the difference particle groups.