Lab Update: July 2017

Hello Microplastics Adventurers,

Thank you for collecting water samples with the Adventure Scientists’ Global Microplastics Initiative. Your efforts are helping us understand the distribution and concentration of microplastics in the world’s waters, while also building one of the largest microplastics datasets ever. Principal Investigator Abby Barrows has processed your microplastics samples, and we’re excited to share the results of your work!

Lab Process

First, let us briefly explain the process your samples go through in the lab. Once Abby receives your sample, she vacuum pumps each sample over a filter. After the filter has dried, Abby uses a microscope at 45x magnification to look for pieces of microplastic that are less than 5 millimeters. Moving along the grid lines, the filter is systematically counted, with each plastic piece categorized based on shape (round, microfiber, other) and color (blue, red, black, transparent/white, other). The final count for the sample is divided by the sample volume. This calculation helps to standardize the results, as incoming water samples are often not exactly one liter of water.

We categorize microplastics using these descriptions:

• Microplastic: a microplastic is any piece of plastic smaller than 5mm in size. We search for and count these small pieces of plastic in our samples. Microplastics can be found in a variety of shapes, typically dependent on the origin of the piece.
  • Round: a spherical or circular piece
  • Fragment: a fragment of plastic is any non-linear, non-round piece. Generally they have jagged edges from breaking off larger pieces of plastic, but can also have smooth edges. Fragments can be three dimensional or two dimensional, such as a fragment of plastic film.
    
  • Filament or Fiber: Filaments or fibers (also called microfibers) are pieces of microplastic originating from textiles. They are long, thin and stringlike. Typically, plastic filaments are consistent in shape and size along their length. They are the most abundant type of microplastic we find in our samples.

Project Results

​To date, 1820 of 2534 samples analyzed (72%) contained microplastics. 86% of marine samples contained plastic, while 47% of freshwater samples contained plastic. 24,814 pieces of microplastic have been counted. On average, we are finding about 8 plastic pieces per liter of water. You can check out the number of pieces per liter in each individual sample on the map on our microplastics page.

Note: In the results listed here, we report the total microplastic pieces found in all of your samples. However, for many of our calculations and for the online map, we report the total pieces per liter. As such, your microplastic total on the map may appear different from your total below.

Also, please let us know if your sample isn’t located in the correct place on the map, so that we can fix it for you.

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