It is raining plastic

Open-File Report 2019-1048
By: , and 

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Abstract

Atmospheric deposition samples were collected using the National Atmospheric Deposition Program / National Trends Network (NADP/NTN) at 6 sites in the Denver-Boulder urban corridor and 2 adjacent sites in the Colorado Front Range. Weekly wet-only atmospheric deposition samples collected at these sites during winter-summer of 2017 were filtered (0.45 micrometers, polyethersulfone) to obtain particulates washed from the atmosphere (washout). Plastics were identified on over 90 percent of the filters. The plastic materials are mostly fibers that are only visible with magnification (~40X). Fibers were present in a variety of colors; the most frequently observed color was blue followed by red > silver > purple > green > yellow > other colors. Plastic particles such as beads and shards were also observed with magnification. More plastic fibers were observed in samples from urban sites than from isolated, montane sites. However, frequent observation of plastic fibers in washout samples from the isolated Loch Vale site in Rocky Mountain National Park (elevation 3,159 meters) suggests that wet-deposition of plastic is ubiquitous and not just an urban condition. The mass of plastic in even the most concentrated samples was not large enough to weigh or reliably estimate. Developing a routine capability to calculate plastic wet-deposition loads is not possible with current technology. Counting plastic fibers under a microscope and multiplying the counts by a mean mass per fiber might be possible, but it is tedious, expensive, and has large inherent error. A means to estimate the recovery of the plastic materials from the NADP samples is needed. However, saving the NADP filters for subsequent analysis would make a washout deposition network possible with very little added expense, and methods could be developed to more accurately estimate plastic loads using the NTN. It is unclear how these plastic materials are accumulating and being assimilated in the environment and biota. Moreover, the potential effects of these materials on biota is not understood.

Suggested Citation

Wetherbee, G., Baldwin, A., Ranville, J., 2019, It is raining plastic.: U.S. Geological Survey Open-File Report 2019–1048, 1 sheet, available at https://doi.org/10.3133/ofr20191048.

ISSN: 2331-1258 (online)

Study Area

Table of Contents

  • Overview
  • Sampling Network
  • Methods
  • Results
  • Discussion
  • References Cited

Additional publication details

Publication type Report
Publication Subtype USGS Numbered Series
Title It is raining plastic
Series title Open-File Report
Series number 2019-1048
DOI 10.3133/ofr20191048
Year Published 2019
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) WMA - Observing Systems Division
Description Report: 28.00 in. x 19.50 in.
Country United States
State Colorado
Online Only (Y/N) Y