Pennsylvania’s Pristine Waterways and Microplastics Appendix


Data Download

Microplastic counts for waterways surveyed

Our study sought to test for the presence of microplastics in waterways, not compare prevalence across waterways. That’s why our findings focus on the number of waterways polluted with plastic, rather than attempting to determine which waterways are most polluted. In case others are interested in further investigating plastic pollution in Pennsylvania’s waterways, we’re sharing the total, average & standard deviation of the data set for each type of plastic at each waterway according to our counts.

When looking at this data, the following notes should be kept in mind: 

  • Sampling location: We were not able to fully standardize the sampling locations within waterways. For example, we were not able to sample from the center of larger waterways, though microplastic concentration may be different near the shore than the center of the waterway.
  • Microscopic power: All samples were examined at 56x magnification. Higher powered microscopes could yield different results.
  • Volume of water: While all samples were collected by filling quart jars, the volume of water was not measured precisely enough to calculate the numbers of particles per volume.
  • Contamination control: Our instructions told samplers to avoid wearing synthetic fibers like fleece when sampling, but we can’t guarantee what they wore.
  • Weather conditions: Samples were collected from October 2021 through May 2022. Since samples were only drawn once from each waterway, we couldn’t control for seasonal conditions like water flow or temperature or for recent weather events like rain or snowfall. 
  • Identification: Because we could not positively identify particles as plastic via FT-IR microspectroscopy, counts were done conservatively as laid out in the Methodology.

To view the full dataset, use the download button.