DOI: 10.25338/b8q335
title: Data from: Expiratory aerosol particle escape from surgical masks due to imperfect sealing

description: The dataset provided here is associated with the
 work "Expiratory aerosol particle escape from surgical masks
 due to imperfect sealing," by Cappa et al, currently available as a
 preprint at https://doi.org/10.21203/rs.3.rs-142138/v1. This
 includes measurements made of the influence of surgical masks and leakage
 flows out the mask sides on the emission of micron-scale
 aerosols from various expiratory activities (coughing, speaking). The
 dataset provided here includes *.txt files exported from an Aerodynamic
 Particle Sizer that contain time-series of the abundance of particles, by
 size (in particles per second), measured in the breath of study
 participants across experiments wherein people were either talking or
 coughing. Also, *.txt files of the measured amplitude of the speech or
 coughing associated with these activities are provided. Data are provided
 for conditions when people were not wearing any masks or were wearing
 surgical masks. For wearing of surgical masks, data are provided for
 participants speaking or coughing while in various physical orientations
 with respect to the sampling instrument. Further details, including the
 file naming scheme, are provided in the associated Read Me file and the
 Usage Notes. All personally identifying information has been removed.
description: <b>Experiment
 Description: </b>Participants were asked to perform various
 expiratory activities (breathing, speaking, coughing) while wearing no
 mask or a mask or surgical mask). Study participants performed these
 activities in front of a funnel connected to an aerodynamic particle sizer
 (APS), which measured the size-dependent aerosol concentration.
 Size-dependent concentrations were measured every 1-second during the
 activities. Additionally, the intensity and duration of the talking and
 coughing activities were measured using a calibrated microphone. The APS
 was located in a HEPA-filtered laminar flow hood to reduce background
 counts to near zero. Participants performed activities in different
 orientations with respect to their position in front of the funnel. These
 included: No mask: facing straight on,
 wearing no mask Forward: facing straight on, wearing
 mask Top: Head tilted downwards to have bridge of
 nose in front of funnel, wearing mask Side: Head
 turned sideways to have edge of mask against cheek in front of funnel,
 wearing mask Bottom: Head tilted upwards or
 above funnel to have chin area in front of funnel, wearing mask
 Further details
 are provided in the associated manuscript (Cappa et al., submitted),
 currently available as a preprint here:
 https://www.researchsquare.com/article/rs-142138/v1 with DOI 10.21203/rs.3.rs-142138/v1. 
description: <b>Files
 Provided:</b> Provided for each
 participant/mask type/expiratory activity are the following
 files: (i) a text
 (.txt) file containing the tab-delimited exported files from the APS.
 Particle sizes are in microns; the smallest size includes all particles
 measured below that size. Particle counts are given for each size every
 second. The APS data were exported from the TSI, Inc. AIM software as tab
 delimited. The file structure for these files is provided below. These
 files are located in subfolders named by participant ID (e.g., “M1” or
 “F1”) and have the naming structure YYYY_ZZZZ_FX or YYYY_ZZZZ_MX, where X
 is the participant number (1-11), YYYY is the designator for each mask
 type (NoMask or SUR = surgical mask), and ZZZZ is the activity (Talk,
 Cough).  (ii) a
 .txt file containing the microphone signals (amplitude, in volts) recorded
 during the activity. The time-interval between points is 2.26757e-5
 seconds. These files are provided for both the talking and coughing
 activities. For coughing, the total time per file is 30 seconds. For
 talking, the total time per file is variable and depends on the amount of
 time it took for the reading, but is around 100 seconds. There is only one
 column per file. These files are located in subfolders named by
 participant ID (e.g., “M1” or “F1”) and have the naming structure
 wav_YYYY_ZZZZ_FX or wav_YYYY_ZZZZ_MX, where X is the participant number
 (1-11), YYYY is the designator for each mask type (NoMask or SUR =
 surgical mask), and ZZZZ is the activity (Talk, Cough).  (iii) A copy of the code used to
 process the loaded data. All analysis was performed in Igor Pro (v. 8.04,
 Wavemetrics). The
 above *.txt files are located in subfolders named by participant ID (e.g.,
 “M1” or “F1”) and have the naming structure YYYY_ZZZZ_FX or YYYY_ZZZZ_MX,
 where X is the participant number (1-11), YYYY is the designator for each
 mask type (NoMask or SUR = surgical mask), and ZZZZ is the activity (Talk,
 Cough).  Data
 were processed using Igor Pro (v. 8.04, Wavemetrics). The data are
 available as a single zip file for download. All personal identifiers have
 been removed.  <i>Folder
 structure:</i> Breath = folder
 containing data associated with breathing Cough = = folder containing data
 associated with coughing <i>File structure for APS
 data files:</i> Line 1: The sample time for each
 spectrum, in seconds (here, 1 second) Line 2: The
 assumed particle density entered in the AIM software, in g/cm^3
 Line3: An indication of whether the Stokes correction was
 applied, off or on Line 4: The lower bound size of the
 smallest particles bin, in microns Line 5: The upper
 bound size of the largest particle bin, in microns Line
 6: The Sample Number Line 7: The date of sample
 measurement (M/D/YYYY) Line 8: The start time of the
 sample measurement, in local time Line 9: First column
 = Aerodynamic Diameter label, Other columns = Raw Counts
 Line 10-61: First Column = the bin-center particle aerodynamic
 diameter, in microns Line 10-61: Other columns = the
 raw counts, in particles per sample time (here,
 particles/second) Line 62-85: Ancillary information
 (not used) Additional files are provided
 summarizing the data shown in Figures 2 and 3. Both text and Excel files
 are provided for convenience. Figure2.txt:
 contains the average particle emission rates (in particles per second) for
 talking or coughing for each participant Figure3.txt: contains the
 particle size distributions averaged over all participants for each
 orientation. The diameter is the aerodynamic diameter (in microns) and the
 size distributions are in dN/dlogDp, with units p/s