Polymer characterization of submerged plastic litter from Lake Tahoe, United States
Data files
Apr 26, 2023 version files 33.75 MB
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Julia_MS_Data_Final.xlsx
33.74 MB
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README.txt
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Jul 26, 2023 version files 33.76 MB
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Julia_MS_Data_Final.xlsx
33.76 MB
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README.txt
4.33 KB
Aug 03, 2023 version files 33.73 MB
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Julia_MS_Data_Final.xlsx
33.73 MB
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README.txt
4.33 KB
Sep 08, 2023 version files 33.73 MB
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Julia_MS_Data_Final.xlsx
33.73 MB
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README.md
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Abstract
Monitoring plastic litter in the environment is critical to understanding the amount, sources, transport, fate, and environmental impact of this pollutant. However, few studies have monitored plastic litter on lakebeds which are potentially important environments for determining the fate and transport of plastic litter in freshwater basins. In this study, self-contained underwater breathing apparatus (SCUBA) was used for litter collection at the lakebed along transects at five locations in Lake Tahoe, United States. Litter was brought to the surface and characterized by litter type. Plastic litter was subsampled for polymer determination using Attenuated Total Reflectance-Fourier Transform InfraRed (ATR-FTIR) spectroscopy. The average plastic litter recovered from the lakebed for the five dive sites was 83 ±49 items per kilometer. The top plastic litter categories were other plastic litter (i.e. plastic litter that did not fall in another category), followed by food containers, plastic bags, toys, and bottles <2 L. These results are in line with prior studies on submerged litter, supporting that intervention approaches or ongoing education is needed. The six polymers most frequently detected in the subsamples were polyvinyl chloride, polystyrene/expanded polystyrene, polyethylene terephthalate/polyester, polyethylene, polypropylene, and polyamide. These observations generally reflect the global plastic production trend and global compilations of microplastic studies from lake surface water and sediments. We found that some litter subcategories were primarily comprised of a single polymer type, therefore, in studies where the polymer type cannot be measured but litter is categorized, these results could provide an estimate of the total polymer composition for select subcategories.
README: Title of Dataset: Polymer characterization of submerged plastic litter from Lake Tahoe, United States
Monitoring plastic litter in the environment is critical to understanding the amount, sources, transport, fate, and environmental impact of this pollutant. However, few studies have monitored plastic litter on lakebeds which is potentially important for determining the fate and transport of plastic litter in freshwaters basins. In this study, self-contained underwater breathing apparatus (SCUBA) was used for litter collection at the lakebed along transects at five locations in Lake Tahoe, Nevada. Litter was brought to the surface and characterized by litter type. Plastic litter was subsampled for polymer determination using Attenuated Total Reflectance-Fourier Transform InfraRed (ATR-FTIR) spectroscopy. Dataset contents include Plastic litter type (code), ATR-FTIR spectral results, and identified plastic type.
Description of the data and file structure
We analyzed 516 plastic litter subsamples using ATR-FTIR. Data are presented by site. For each site, information on the plastic category, identified plastics, and spectral results.
The polymer of each subsample was determined through Attenuated Total Reflectance-Fourier Transform InfraRed (ATR-FTIR) spectroscopy using a Thermo Nicolet 6700 FTIR at the University of Nevada, Reno. Spectra were collected using 32 scans with a spectral resolution of 4 cm-1 within the range of 3950 and 650 cm-1. The background was subtracted from each spectrum automatically by the instrument software. The subtracted background was measured every six spectra (approximately every 10 minutes). The diamond eyepiece was cleaned with acetone before every background collection. Each sample spectrum was compared to known spectra in the Hummel Polymer Library Database and a database created from the spectra of plastics in the Center for Marine Debris Research Polymer Kit 1.0 collected using the same settings as described above.
The database spectrum best fitted to the spectrum of the unknown sample was considered to be the identity of that sample. The polymer match was categorized as “unknown polymer” when the best match was less than a 70% similarity. For each subsample analyzed, we noted the polymer type and match percent.
Litter code - Found in Column 1 Litter type Litter type sub category
- PL01 Plastic Bottle caps & lids
- PL02 Plastic Bottles < 2 L
- PL03 Plastic Bottles, drums, jerrycans & buckets > 2 L
- PL04 Plastic Knives, forks, spoons, straws, stirrers, (cutlery)
- PL05 Plastic Drink package rings, six-pack rings, ring carriers
- PL06 Plastic Food containers (fast food, cups, lunch boxes & similar)
- PL07 Plastic Plastic bags (opaque & clear)
- PL08 Plastic Toys & party poppers
- PL09 Plastic Gloves
- PL10 Plastic Cigarette lighters
- PL11 Plastic Cigarettes, butts & filters
- PL12 Plastic Syringes
- PL13 Plastic Baskets, crates & trays
- PL14 Plastic Plastic buoys
- PL15 Plastic Mesh bags
- PL16 Plastic Sheeting (tarpaulin or other woven plastic bags, palette wrap)
- PL17 Plastic Fishing gear (lures, traps & pots)
- PL18 Plastic Monofilament line
- PL19 Plastic Rope
- PL20 Plastic Fishing net
- PL21 Plastic Strapping
- PL22 Plastic Fibreglass fragments
- PL23 Plastic Resin pellets
- PL24 Plastic Other
Abbreviation - Found in Row 2 Polymer
- PVC Polyvinyl Chloride
- PET/PEST Polyethylene terephthalate/Polyester
- PS/EPS Polystyrene/Expanded polystyrene
- PE Polyethylene
- PP Polypropylene
- PA6/PA66 Polyamide 6/Polyamide 6,6
- ABS Acrylonitirile-Butadiene-Styrene
- PC Polycarbonate
- ABS Acrylonitirile-Butadiene-Styrene
- EVA Ethylene Vinyl Acetate
Location Name Start transect Stop transect
- Nevada Beach 38.97663789, -119.9540862 38.98852004, -119.95471108
- Zephyr Cove 39.00575679, -119.95310787 39.01787844, -119.95392789
- South Sand Harbor 39.19329585, -119.92800956 39.17897252, -119.92699464
- East Incline 39.22302604, -119.93251783 39.23640226, -119.94604386
- Hidden Beach 39.22308327, -119.93215629 39.2164737, -119.92872056
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Methods
The polymer of each subsample (n=516) was determined through Attenuated Total Reflectance-Fourier Transform InfraRed (ATR-FTIR) spectroscopy using a Thermo Nicolet 6700 FTIR (ThermoFisher, United States) at the University of Nevada, Reno. Spectra were collected using 32 scans with a spectral resolution of 4 cm-1 within the range of 3950 and 650 cm-1. The Norton-Beer strong apodization function was applied by the instrument software (OMNIC software, ThermoFisher, United States) and the background was subtracted from each spectrum automatically by the software. The subtracted background was measured every six spectra (approximately every 10 minutes). The diamond ATR crystal was cleaned with isopropanol/methanol before every background collection. Each sample spectrum was compared to known spectra in the Hummel Polymer Library Database and a database created from the spectra of plastics in the Center for Marine Debris Research Polymer Kit 1.0 (Hawaii Pacific University, United States) collected using the same settings as described above.
In the OMNIC software, we used the correlation approach for comparing the spectra to the libraries. The match value ranges from 0 to 100, with a match of 100 indicating a perfect match. The library match best fitted to the unknown sample spectrum was considered to be the identity of that sample. The polymer match was categorized as “unknown polymer” when the best match was less than a 70% similarity. All matches were additionally verified by the instrument user. For each subsample analyzed, we noted the polymer type and match.
Usage notes
Excel file can be opened with most data viewing programs.