Quantity, Size Distribution, and Characteristics of Cough-generated Aerosol Produced by Patients with an Upper Respiratory Tract Infection

Lee, Jinho; Yoo, Dallah; Ryu, Seung-Hun; Ham, Seunghon; Lee, Kiyoung; Yeo, Myoung-Souk; Min, Kyoung-Bok; Yoon, Chungsik

doi:10.4209/aaqr.2018.01.0031

Cited by 97 publications

(100 citation statements)

References 27 publications

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“…We note that our previous work [10] examining expiratory particle emission while reading a passage of text (Chapter 24 of "The Little Prince") in different languages-Spanish, Mandarin, and Arabic-yielded data that could be analyzed in more detail by linguists with expertise in those languages. Moreover, it has been previously reported that the number of cough aerosols released during illness was significantly larger compared to subsequent post-illness measurements [32,33]. This result raises the question of whether a similar trend would be observed for talking and breathing when comparing healthy and ill subjects.…”

Section: Resultsmentioning

confidence: 83%

Effect of voicing and articulation manner on aerosol particle emission during human speech

Asadi¹,

Wexler²,

Cappa³

et al. 2020

PLoS ONE

157

196

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Previously, we demonstrated a strong correlation between the amplitude of human speech and the emission rate of micron-scale expiratory aerosol particles, which are believed to play a role in respiratory disease transmission. To further those findings, here we systematically investigate the effect of different 'phones' (the basic sound units of speech) on the emission of particles from the human respiratory tract during speech. We measured the respiratory particle emission rates of 56 healthy human volunteers voicing specific phones, both in isolation and in the context of a standard spoken text. We found that certain phones are associated with significantly higher particle production; for example, the vowel /i/ ("need," "sea") produces more particles than /ɑ/ ("saw," "hot") or /u/ ("blue," "mood"), while disyllabic words including voiced plosive consonants (e.g., /d/, /b/, /g/) yield more particles than words with voiceless fricatives (e.g., /s/, /h/, /f/). These trends for discrete phones and words were corroborated by the time-resolved particle emission rates as volunteers read aloud from a standard text passage that incorporates a broad range of the phones present in spoken English. Our measurements showed that particle emission rates were positively correlated with the vowel content of a phrase; conversely, particle emission decreased during phrases with a high fraction of voiceless fricatives. Our particle emission data is broadly consistent with prior measurements of the egressive airflow rate associated with the vocalization of various phones that differ in voicing and articulation. These results suggest that airborne transmission of respiratory pathogens via speech aerosol particles could be modulated by specific phonetic characteristics of the language spoken by a given human population, along with other, more frequently considered epidemiological variables.

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Section: Resultsmentioning

confidence: 83%

Effect of voicing and articulation manner on aerosol particle emission during human speech

Asadi¹,

Wexler²,

Cappa³

et al. 2020

PLoS ONE

157

196

View full text Add to dashboard Cite

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“…For example, the average number of aerosols generated per cough by In uenza patient is 7.5*10 4 and count median diameter (CMD) of cough generated aerosols/droplet were in between 0.6 to 0.9 µm with Geometric Standard Deviation (GSD) 1.53 to 2.28 (Lindsley et al, 2012). Similarly, another recent study suggests that, the average number of droplet/aerosols expelled per cough by a person having respiratory infection is 4.9*10 6 with most of the aerosols are less than 5.0 µm and aerosol number becomes less when person recovered from the infection (Lee et al, 2019). Another study shows that 80% of droplets/aerosols are centred in the range of 0.74 2.12 µm during coughing and sneezing (Yang et al, 2007).…”

Section: Resultsmentioning

confidence: 87%

“…The surgical masks are made of 3 layered gauze having high count gauze (40 x 24) at the outer side and two layers of normal gauze (28 x 24 counts) on the inner side. The tests are conducted at two constant ow rate conditions at 20 and 90 L min -1 corresponding to breathing rate during light activity and sneezing/coughing respectively(Adams, 1993;Lee et al, 2019). The number of masks tested in each type are summarised inTable 1.…”

mentioning

confidence: 99%

Quantitative Performance Analysis of Respiratory Facemasks using Atmospheric and Laboratory generated Aerosols following with Gamma Sterilization

Kumar

Sangeetha

Yuvaraj

et al. 2020

Preprint

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The emergence of the recent Covid-19 pandemic has rendered mandatory wearing of respiratory masks by infected persons, frontline workers, security personnel and members of the public. This has caused a sudden shift of focus and significant demand on availability, effectiveness, reuse after sterilization and development of facemask. Toward this, three types of masks viz. N95, nonwoven fabric and double layer cotton cloth are being used by the majority of the population across the world as an essential inhalation protective measure for suppressing the entry of virus- laden respiratory droplets. The Filtering Efficiency (FE) of these masks are tested for atmospheric and laboratory generated aerosols of size 1.0 µm and 102.7 nm particles before and after sterilisation and for the two flow rate conditions corresponding to normal breath rate and during sneezing/coughing. Sterilisation is carried out using a gamma irradiator containing Co-60 source for the two-dose exposures viz. 15 kGy and 25 kGy. The FE of surgical and cloth masks is found to be in the range of 15.76±0.22 to 22.48±3.92%, 49.20±8.44 to 60±7.59% and 73.15±3.73 to 90.36±4.69% for aerosol sizes 0.3˗5.0, 1.0˗5.0 and 3.0˗5.0 µm atmospheric aerosols respectively. The FE of cloth and surgical masks ranges from 45.07±6.69% to 63.89±4.44% and 56.58±1.69% to 83.95±1.04% for 1.0 µm laboratory generated aerosol for two flow rate, control and irradiated conditions. The FE of N95 mask is found to be more than 95% for atmospheric aerosol and 1.0 µm laboratory generated aerosol. However, FE reduced to about 70% for most penetrating particle size after sterilisation. Further, FE reduced to 84% for the particle >0.3 µm and to 87% for the particle <0.3 µm after sterilisation. The reduction in FE for N95 mask after sterilization is associated with reduction of electrostatic interaction of filter medium with particles laden in the air stream. Instead of disposing of N95 masks after single use, they can be reused a few times as N70 mask during this pandemic crisis after sterilisation. The use of cotton cloth masks in the general public serves fit for the purpose than surgical masks.

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“…Aerosol particles from patients (10 subjects) with an upper respiratory tract infection were measured by Lee et al (2019) under clean air conditions [ 13 ]. The size of the particles generated from these patients ranged from <0.1 μm to 10 μm.…”

Section: Respiratory Particlesmentioning

confidence: 99%

“…Additionally, the characteristics of the generated respiratory particles in the aforementioned studies were found to be related to human health conditions. For instance, in studies conducted on patients suffering from influenza and upper respiratory tract infections, the number of generated aerosol particles decreased when the subjects recovered from diseases [ 12 , 13 ].…”

Section: Respiratory Particlesmentioning

confidence: 99%

Minimum Sizes of Respiratory Particles Carrying SARS-CoV-2 and the Possibility of Aerosol Generation

Lee

2020

IJERPH

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This study calculates and elucidates the minimum size of respiratory particles that are potential carriers of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2); furthermore, it evaluates the aerosol generation potential of SARS-CoV-2. The calculations are based on experimental results and theoretical models. In the case of maximum viral-loading derived from experimental data of COVID-19 patients, 7.18 × 10−4% of a respiratory fluid particle from a COVID-19 patient is occupied by SARS-CoV-2. Hence, the minimum size of a respiratory particle that can contain SARS-CoV-2 is calculated to be approximately 4.7 μm. The minimum size of the particles can decrease due to the evaporation of water on the particle surfaces. There are limitations to this analysis: (a) assumption that the viruses are homogeneously distributed in respiratory fluid particles and (b) considering a gene copy as a single virion in unit conversions. However, the study shows that high viral loads can decrease the minimum size of respiratory particles containing SARS-CoV-2, thereby increasing the probability of aerosol generation of the viruses. The aerosol generation theory created in this study for COVID-19 has the potential to be applied to other contagious diseases that are caused by respiratory infectious microorganisms.

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Quantity, Size Distribution, and Characteristics of Cough-generated Aerosol Produced by Patients with an Upper Respiratory Tract Infection

Cited by 97 publications

References 27 publications

Effect of voicing and articulation manner on aerosol particle emission during human speech

Effect of voicing and articulation manner on aerosol particle emission during human speech

Quantitative Performance Analysis of Respiratory Facemasks using Atmospheric and Laboratory generated Aerosols following with Gamma Sterilization

Minimum Sizes of Respiratory Particles Carrying SARS-CoV-2 and the Possibility of Aerosol Generation

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