DOI: 10.5061/dryad.prr4xgxzf
title: Data from: A participatory science approach to quantify microfiber emissions from clothes dryers

description: Studies have shown that washing and drying clothes contribute microfiber
 contamination to the environment. However, many of the previous studies on
 clothes drying were conducted under idealized conditions. To better
 understand microfiber emissions from clothes dryers during normal
 household use, we recruited participatory volunteer scientists to install
 a mesh on their dryer vents for three weeks. During that time, the
 volunteers used a mobile application to record the item dried (e.g.,
 pants, shirt, etc.) and the material composition (e.g., cotton, acrylic,
 silk). The mesh was then returned and the accumulated material was
 removed, weighed, and analyzed. The results showed that the items dried
 were primarily comprised of cotton, followed by polyester. The
 textile-derived microfibers on the mesh were primarily cellulose, followed
 by polyethylene terephthalate/polyester and other plastics. When we
 compared the microfibers on the mesh to the textiles dried, we found that
 the relative percentage of cellulosic microfibers on the mesh was higher
 than the percentage of cellulosic textiles dried. This suggests that
 cellulosic textiles released more microfibers than synthetic textiles. On
 average, 138 mg of material was emitted per dryer load. When scaled to the
 number of electric clothes dryers in the United States and the average
 number of dryer loads per household per year, we estimated dryers release
 ~3,543.6 metric tons of microfibers per year. The results indicate that
 clothes dryers are potentially a significant source of cellulosic and
 synthetic microfibers being released into the air, and steps should be
 taken to reduce these emissions. The methods outlined here can be applied
 to other studies to assess microfiber emissions from dryers under normal
 household use.
description: <strong>Project design and participant
 recruitment</strong> This study was a
 participatory science project, during which volunteers were asked to
 participate by either: 1) installing a mesh over their dryer vent to
 collect microfiber emissions, submitting information about their dryer
 habits during the three weeks the mesh was installed, and mailing the mesh
 back to DRI or 2) only submitting information about their dryer habits
 without installing the mesh to collect microfibers. We recruited
 volunteers through the League to Save Lake Tahoe, a nonprofit organization
 located in South Lake Tahoe, California. The project began in April of
 2020 and ended in August of 2020. To recruit
 participants, the League to Save Lake Tahoe emailed information about the
 project to their list of volunteers. The email directed potentially
 interested individuals to fill out a Google form, which asked about their
 dryer system, their household, and their interest in installing the mesh
 outside their home (see the supplementary materials). Individuals
 interested in installing the mesh over their dryer vent were then invited
 to an online video conference, during which we reviewed the research
 questions and goals, methodologies, and expectations of the project. This
 meeting was also used to confirm participant interest. Seven individuals
 agreed to participate by installing the mesh over their dryer vent.
 Individuals who did not want to participate by installing the mesh were
 invited to submit data on their drying habits (see section
 below). <strong>Dryer vent
 mesh</strong> To create the mesh that would sit
 over the dryer vent exhaust, we first purchased a plastic dryer vent guard
 (these are typically used to keep animals from entering the dryer vent).
 Inside the dryer vent guard, we installed a custom-fit mesh with 1 mm x 1
 mm openings made from screening material (vinyl-coated fiberglass). The
 dryer vent guard provided the mesh stability during transport and allowed
 for easy installation by the volunteers. Each mesh was numbered and
 weighed. The mesh was then mailed with the dryer vent guard and
 instructions to the citizen volunteers.
 <strong>Installation of the mesh and data
 reporting</strong> Volunteers were asked to
 install the mesh and dryer vent guard by July 12, 2020, and to begin
 recording their clothes drying habit data once it was installed.
 Installation instructions were provided during the initial online video
 meeting, as well as through written instructions. To our knowledge, no
 issues arose during installation. After installation,
 the volunteers were asked to record data every time they used their dryer.
 The data collection survey was hosted on the existing Citizen Science
 Tahoe (CST) smartphone application platform. Zach Lyon Creative developed
 the CST app in 2015 in collaboration with three regional groups: the
 University of California Davis Tahoe Environmental Research Center, the
 League to Save Lake Tahoe, and DRI. In 2020, the CST app hosted six
 different citizen science surveys used by CST partners, with a total
 network of 1,970 registered users. We have successfully used the CST app
 for other participatory science projects (Arienzo et al., 2021). The “DRI:
 Clothes Drying Habits” survey included a series of screens for the users
 to submit data. The first screen asked the users to enter the number on
 their assigned dryer mesh or to enter zero if they did not have a mesh on
 their dryer vent. Since the CST app is publicly available, we wanted users
 to enter their dryer number because potentially anyone using the app could
 submit to the survey. The following screens included questions about the
 dryer setting, the two largest items dried (e.g., pants, towel, or sheet),
 and the composition of the two largest items (e.g., nylon, polypropylene,
 etc.). The date and time of the data submission was recorded automatically
 by the CST app. To remind volunteers to submit data during the experiment,
 we followed up with emails and text messages to ensure data submission and
 answer any questions volunteers had. After three weeks of the mesh being
 installed in the dryer vent, we asked the volunteers to return the mesh to
 DRI using a prepaid return envelope.
 <strong>Laboratory processes</strong>
 Once DRI received the mesh, it was reweighed in the laboratory to
 calculate the weight of the accumulated microfibers (weight data are
 available in the manuscript text). All the material from the mesh was then
 collected and stored in a glass jar labeled with the number of the
 associated mesh. Subsamples of microfibers were taken from the collected
 material, and then analyzed for chemical composition using
 microscope-enable Fourier Transform Infrared (mFTIR) spectroscopy (Thermo
 Nicolet iN10 MX). The subsample was placed on a zinc selenium (ZnSe) IR
 transparent window (13 mm diameter by 2 mm window, Pike Technologies,
 Madison, WI, USA). We ensured that the particles on the ZnSe slide were
 not overlapping and one quarter of the slide was imaged by the instrument.
 We then used the particle identification tool to select the particles of
 interest, and the instrument collected data for each identified particle.
 The spectra were collected using spectral resolution of 8
 cm<sup>−1</sup> (from 4000 to 715 cm<sup>−1</sup>
 ) and 64 scans. The Norton−Beer strong apodization function was applied by
 the instrument software. The particle identification tool automatically
 collected the background spectra using the same settings as part of the
 particle analysis. The particle identification tool also automatically
 collected length and width estimates of the analyzed microfibers. We
 compiled the microfiber length and width data for dryer vents 1, 2, 4, 5,
 and 7. The resulting spectra were processed using Open
 Specy (Cowger et al., 2021). We applied an absolute derivative
 transformation of the first order and smoothed the data using a polynomial
 order 3 and a moving window of 11 data points (88
 cm<sup>−1</sup>). The processed spectra were then compared
 against the derivative corrected library in Open Specy and matched with
 library spectra using the built-in Pearson correlation search algorithm. A
 match percent ≥70% was used to identify the chemical composition. All
 matches ≥70% were also verified by the instrument user. Particles that had
 a match &lt;70% were not considered in the analysis. This has been
 previously shown to be a robust data processing approach (Kozloski et al.,
 2024). To aid in comparison with the volunteer data, microfibers that were
 identified as either polyethylene terephthalate (PET) or polyester (PEST)
 were categorized together (PET/PEST) because for textiles, most PEST is
 PET (Geyer et al., 2017).
description: # Data from: A participatory science approach to quantify microfiber
 emissions from clothes dryers Dataset DOI:
 [10.5061/dryad.prr4xgxzf](10.5061/dryad.prr4xgxzf) ## Description of the
 data and file structure ### Files and variables #### File:
 Dryer_user_data.csv **Description:** dryer user data ##### Variables *
 DryerNo:Dryer mesh number, zero indicates no mesh installed * Item:Item
 that was dried. * Textile:Textile composition. #### File: DryerVent1.xlsx
 **Description:** results from analysis of dryer vent #1 ##### Variables |
 library\_id | library match id | | :------------------ |
 :-------------------------------------------------------------------------------------------------------------- | | match\_val | match value | | match\_threshold | match threshold was set to 0.7 | | good\_correlations | true = correlation greater than or equal to 0.7 | | signal\_to\_noise | signal to noise determined by Open Specy | | signal\_threshold | set to 4 | | good\_signal | true = signal to noise was &gt;4 | | good\_matches | true = true for good\_correlations and true for good\_signal | | file\_name | original filename for the spectra | | SpectrumID | added by openspecy - this is the spectrum ID that the sample matched too. | | Organization | added by openspecy - this is the organization that generated the spectrum that the sample matched too.  | | SpectrumType | added by openspecy  - this is the type of instrument used to generate the spectrum, either Raman or FTIR | | SpectrumIdentity | added by openspecy  - this is the identity of the spectrum that the sample matched too.  | | polymer\_class | added by openspecy    - this is the class of polymer or natural material based on what the sample matched too.  | | plastic\_or\_not | added by openspecy - if the match was to a plastic item then "plastic" otherwise "not plastic" | | url\_polymer\_class | metadata for the spectral library match   - infromation about the polymer class | | polymer | additional information about the polymer type that was matched too if more specifics are needed.  | | Length | length was calculated by the instrument software in micrometer, NA, not available | | Width | width was calculated by the instrument software in micrometer, NA, not available | #### File: DryerVent2.xlsx **Description:** results from analysis of dryer vent #2 ##### Variables | library\_id | library match id | | :------------------ | :-------------------------------------------------------------------------------------------------------------- | | match\_val | match value | | match\_threshold | match threshold was set to 0.7 | | good\_correlations | true = correlation greater than or equal to 0.7 | | signal\_to\_noise | signal to noise determined by Open Specy | | signal\_threshold | set to 4 | | good\_signal | true = signal to noise was &gt;4 | | good\_matches | true = true for good\_correlations and true for good\_signal | | file\_name | original filename for the spectra | | SpectrumID | added by openspecy - this is the spectrum ID that the sample matched too. | | Organization | added by openspecy - this is the organization that generated the spectrum that the sample matched too.  | | SpectrumType | added by openspecy  - this is the type of instrument used to generate the spectrum, either Raman or FTIR | | SpectrumIdentity | added by openspecy  - this is the identity of the spectrum that the sample matched too.  | | polymer\_class | added by openspecy    - this is the class of polymer or natural material based on what the sample matched too.  | | plastic\_or\_not | added by openspecy - if the match was to a plastic item then "plastic" otherwise "not plastic" | | url\_polymer\_class | metadata for the spectral library match   - infromation about the polymer class | | polymer | additional information about the polymer type that was matched too if more specifics are needed.  | | Length | length was calculated by the instrument software in micrometer, NA, not available | | Width | width was calculated by the instrument software in micrometer, NA, not available | #### File: DryerVent4.xlsx **Description:** results from analysis of dryer vent #4results from analysis of dryer vent #4 ##### Variables | library\_id | library match id | | :------------------ | :-------------------------------------------------------------------------------------------------------------- | | match\_val | match value | | match\_threshold | match threshold was set to 0.7 | | good\_correlations | true = correlation greater than or equal to 0.7 | | signal\_to\_noise | signal to noise determined by Open Specy | | signal\_threshold | set to 4 | | good\_signal | true = signal to noise was &gt;4 | | good\_matches | true = true for good\_correlations and true for good\_signal | | file\_name | original filename for the spectra | | SpectrumID | added by openspecy - this is the spectrum ID that the sample matched too. | | Organization | added by openspecy - this is the organization that generated the spectrum that the sample matched too.  | | SpectrumType | added by openspecy  - this is the type of instrument used to generate the spectrum, either Raman or FTIR | | SpectrumIdentity | added by openspecy  - this is the identity of the spectrum that the sample matched too.  | | polymer\_class | added by openspecy    - this is the class of polymer or natural material based on what the sample matched too.  | | plastic\_or\_not | added by openspecy - if the match was to a plastic item then "plastic" otherwise "not plastic" | | url\_polymer\_class | metadata for the spectral library match   - infromation about the polymer class | | polymer | additional information about the polymer type that was matched too if more specifics are needed.  | | Length | length was calculated by the instrument software in micrometer, NA, not available | | Width | width was calculated by the instrument software in micrometer, NA, not available | #### File: DryerVent5.xlsx **Description:** results from analysis of dryer vent #5 ##### Variables | library\_id | library match id | | :------------------ | :-------------------------------------------------------------------------------------------------------------- | | match\_val | match value | | match\_threshold | match threshold was set to 0.7 | | good\_correlations | true = correlation greater than or equal to 0.7 | | signal\_to\_noise | signal to noise determined by Open Specy | | signal\_threshold | set to 4 | | good\_signal | true = signal to noise was &gt;4 | | good\_matches | true = true for good\_correlations and true for good\_signal | | file\_name | original filename for the spectra | | SpectrumID | added by openspecy - this is the spectrum ID that the sample matched too. | | Organization | added by openspecy - this is the organization that generated the spectrum that the sample matched too.  | | SpectrumType | added by openspecy  - this is the type of instrument used to generate the spectrum, either Raman or FTIR | | SpectrumIdentity | added by openspecy  - this is the identity of the spectrum that the sample matched too.  | | polymer\_class | added by openspecy    - this is the class of polymer or natural material based on what the sample matched too.  | | plastic\_or\_not | added by openspecy - if the match was to a plastic item then "plastic" otherwise "not plastic" | | url\_polymer\_class | metadata for the spectral library match   - infromation about the polymer class | | polymer | additional information about the polymer type that was matched too if more specifics are needed.  | | Length | length was calculated by the instrument software in micrometer, NA, not available | | Width | width was calculated by the instrument software in micrometer, NA, not available | #### File: DryerVent8.xlsx **Description:** results from analysis of dryer vent #8 ##### Variables | library\_id | library match id | | :------------------ | :-------------------------------------------------------------------------------------------------------------- | | match\_val | match value | | match\_threshold | match threshold was set to 0.7 | | good\_correlations | true = correlation greater than or equal to 0.7 | | signal\_to\_noise | signal to noise determined by Open Specy | | signal\_threshold | set to 4 | | good\_signal | true = signal to noise was &gt;4 | | good\_matches | true = true for good\_correlations and true for good\_signal | | file\_name | original filename for the spectra | | SpectrumID | added by openspecy - this is the spectrum ID that the sample matched too. | | Organization | added by openspecy - this is the organization that generated the spectrum that the sample matched too.  | | SpectrumType | added by openspecy  - this is the type of instrument used to generate the spectrum, either Raman or FTIR | | SpectrumIdentity | added by openspecy  - this is the identity of the spectrum that the sample matched too.  | | polymer\_class | added by openspecy    - this is the class of polymer or natural material based on what the sample matched too.  | | plastic\_or\_not | added by openspecy - if the match was to a plastic item then "plastic" otherwise "not plastic" | | url\_polymer\_class | metadata for the spectral library match   - infromation about the polymer class | | polymer | additional information about the polymer type that was matched too if more specifics are needed.  | | Length | length was calculated by the instrument software in micrometer, NA, not available | | Width | width was calculated by the instrument software in micrometer, NA, not available | #### File: DryerVent7.xlsx **Description:** results from analysis of dryer vent #7 ##### Variables | library\_id | library match id | | :------------------ | :-------------------------------------------------------------------------------------------------------------- | | match\_val | match value | | match\_threshold | match threshold was set to 0.7 | | good\_correlations | true = correlation greater than or equal to 0.7 | | signal\_to\_noise | signal to noise determined by Open Specy | | signal\_threshold | set to 4 | | good\_signal | true = signal to noise was &gt;4 | | good\_matches | true = true for good\_correlations and true for good\_signal | | file\_name | original filename for the spectra | | SpectrumID | added by openspecy - this is the spectrum ID that the sample matched too. | | Organization | added by openspecy - this is the organization that generated the spectrum that the sample matched too.  | | SpectrumType | added by openspecy  - this is the type of instrument used to generate the spectrum, either Raman or FTIR | | SpectrumIdentity | added by openspecy  - this is the identity of the spectrum that the sample matched too.  | | polymer\_class | added by openspecy    - this is the class of polymer or natural material based on what the sample matched too.  | | plastic\_or\_not | added by openspecy - if the match was to a plastic item then "plastic" otherwise "not plastic" | | url\_polymer\_class | metadata for the spectral library match   - infromation about the polymer class | | polymer | additional information about the polymer type that was matched too if more specifics are needed.  | | Length | length was calculated by the instrument software in micrometer, NA, not available | | Width | width was calculated by the instrument software in micrometer, NA, not available | #### File: README.xlsx **Description:** readme.xlsx of the variables ### Change Log **22-Jul-25**: Added length and width for the particles analyzed and made a few edits to README wording.