OBJECTIVE: Due to the COVID-19 pandemic and the shortage of the National Institute for Occupational Safety & Health (NIOSH)-approved N95 respirators, the Food and Drug Administration granted an Emergency Use Authorization to allow the use of non-NIOSH approved respirators provided that these respirators must undergo tests by a protocol of TEB-APR-STP-0059, similar methods of NIOSH standard testing procedure. This initiative safeguards the quality of respirators and the effectiveness of occupational protection. The dataset of all the testing results could benefit further analysis of COVID-19 infection rates in relation to different types of N95 respirators used and identify potential correlations of various test parameters in the testing system for validation. The analysis enhances understanding of the quality, effectiveness, and performance of N95 respirators in the prevention of respiratory infectious transmission and develops improved occupational safety measures.
METHODS: The dataset was transformed, transcribed, and compiled from the official testing data of non-NIOSH-approved N95 respirators reported in the NIOSH website under the Centers for the Disease Control and Prevention in the United States. The dataset included details of 7,413 testing results of N95 respirators (manufacturer, model, and maximum and minimum filtration efficiency) and test parameters (flow rate, initial filter resistance, and initial percent leakage). Supplementary items were added to increase the availability of data analysis and enhance the interpretability of the assessments of the quality of N95 respirators.

BACKGROUND: Tight-fitting masks and respirators, in manikin studies, improved aerosol source control compared to loose-fitting masks. Whether this translates to humans is not known.
METHODS: We compared efficacy of masks (cloth and surgical) and respirators (KN95 and N95) as source control for SARS-CoV-2 viral load in exhaled breath of volunteers with COVID-19 using a controlled human experimental study. Volunteers (N = 44, 43% female) provided paired unmasked and masked breath samples allowing computation of source-control factors.
RESULTS: All masks and respirators significantly reduced exhaled viral load, without fit tests or training. A duckbill N95 reduced exhaled viral load by 98% (95% CI: 97%-99%), and significantly outperformed a KN95 (p < 0.001) as well as cloth and surgical masks. Cloth masks outperformed a surgical mask (p = 0.027) and the tested KN95 (p = 0.014).
CONCLUSIONS: These results suggest that N95 respirators could be the standard of care in nursing homes and healthcare settings when respiratory viral infections are prevalent in the community and healthcare-associated transmission risk is elevated.
BACKGROUND: Defense Advanced Research Projects Agency, National Institute of Allergy and Infectious Diseases, Centers for Disease Control and Prevention, the Bill & Melinda Gates Foundation, and The Flu Lab.

The increasing demand for personal protective equipment such as single-use masks has led to large amounts of nondegradable plastic waste, aggravating economic and environmental burdens. This study reports a simple and scalable approach for upcycling waste masks via a chemical vapor deposition technique, realizing a trichome-like biomimetic (TLB) N95 respirator with superhydrophobicity (water contact angle ≥150°), N95-level protection, and reusability. The TLB N95 respirator comprising templated silicone nanofilaments with an average diameter of ∼150 nm offers N95-level protection and breathability comparable to those of commercial N95 respirators. The TLB N95 respirator can still maintain its N95-level protection against particulate matter and viruses after 10 disinfection treatment cycles (i.e., ultraviolet irradiation, microwave irradiation, dry heating, and autoclaving), demonstrating durable reusability. The proposed strategy provides new insight into upcycle waste masks, breaking the existing design and preparation concept of reusable masks.

BACKGROUND: During the coronavirus disease 2019 pandemic, wearing medical respirators and masks was essential to prevent transmission.
OBJECTIVE: To quantify the effects of N95 mask usage by measuring facial skin biophysical characteristics and changes in the lipidome.
METHODS: Sixty healthy volunteers wore N95 respirators for 3 or 6 h. Facial images were acquired and physiological parameters were measured in specific facial areas, before and after mask-wearing. Lipidome analysis was also performed.
RESULTS: After N95 respirator usage, facial erythema was observed in both the 3 and 6 h groups. Both sebum secretion and trans-epidermal water loss increased significantly in mask-covered cheeks and chins after 6 h of mask wearing compared with before mask wearing (p < 0.05). Principal component analysis revealed significant differences in lipid composition after mask wearing compared with before. The ceramide subclass NS exhibited a positive correlation with stratum corneum hydration, whereas the AP subclass was negatively correlated with trans-epidermal water loss in the 6 h group.
CONCLUSIONS: Prolonged wear of N95 respirators may impair facial skin function and alter lipidome composition.

N95 respirators are the core equipment used by healthcare workers to prevent the spread of respiratory diseases. The protective effect of N95 against infection spread depends on the fit of the N95 to the wearer, which is related to the wearer\'s facial dimensions. The purpose of this cross-sectional study was to assess the relationship between the fit of three types of N95 and facial dimensions. A total of 305 healthcare workers from ten hospitals in Beijing were recruited for this study. Facial dimensions of workers were measured using Intel RealSense Depth Camera D435. Fit testing was conducted on three types of N95 using the TSI-8038 Porta Count Pro + Respirator Fit Tester. Possible associations between the fit test results and facial dimension data were examined. A Porta Count reading of 100 was used as the criterion for an acceptable fit. The fit of the folding respirators was positively correlated with nose length (r = 0.13, p = 0.02), nose height (r = 0.14, p = 0.02), and face width (r = 0.12, p = 0.03), whereas that of flat respirators was correlated with nose width (r = 0.16, p < 0.01), chin length (r = 0.18, p < 0.01), and pro-face width (r = 0.13, p = 0.02), and that of arched respirators was correlated with the nose length (r = 0.13, p = 0.03). The fit of N95 for wearers depends on their facial features. The results of this study can provide advice for medical workers to choose the appropriate N95. Medical staff should fully consider their facial dimensions when choosing an appropriate N95 to improve the protective efficacy of respirators and to reduce the risk of infection by respiratory diseases.

[This corrects the article DOI: 10.3389/fpubh.2023.1266607.].

UNASSIGNED: During hot environment work tasks with whole-body enclosed anti-bioaerosol suit, the combined effect of heavy sweating and exhaled hot humid air may cause the N95 medical respirator to saturate with water/sweat (i.e., water-blocking).
UNASSIGNED: 32 young male subjects with different body mass indexes (BMI) in whole-body protection (N95 medical respirator + one-piece protective suit + head covering + protective face screen + gloves + shoe covers) were asked to simulate waste collecting from each isolated room in a seven-story building at 27-28°C, and the weight, inhalation resistance (Rf), and aerosol penetration of the respirator before worn and after water-blocking were analyzed.
UNASSIGNED: All subjects reported water-blocking asphyxia of the N95 respirators within 36-67 min of the task. When water-blocking occurred, the Rf and 10-200 nm total aerosol penetration (Pt) of the respirators reached up to 1270-1810 Pa and 17.3-23.3%, respectively, which were 10 and 8 times of that before wearing. The most penetration particle size of the respirators increased from 49-65 nm before worn to 115-154 nm under water-blocking condition, and the corresponding maximum size-dependent aerosol penetration increased from 2.5-3.5% to 20-27%. With the increase of BMI, the water-blocking occurrence time firstly increased then reduced, while the Rf, Pt, and absorbed water all increased significantly.
UNASSIGNED: This study reveals respirator water-blocking and its serious negative impacts on respiratory protection. When performing moderate-to-high-load tasks with whole-body protection in a hot environment, it is recommended that respirator be replaced with a new one at least every hour to avoid water-blocking asphyxia.

N95 respirators are used to limit the transmission of respiratory viruses in clinical settings. There are two to three major types of N95 available for all healthcare workers in Hong Kong. However, after the coronavirus outbreak and the consequent shortage of many commonly used respirators, several new N95 respirators were adopted temporarily in clinical settings without evaluation. Prior literature indicates that traditional N95 respirators used in hospitals in Hong Kong are not fit for Chinese people and have fit rates ranging from 50 to 60%. This study aims to investigate and compare the fit rate, real-time leakage, and mask usability of traditional and new N95 respirators among Chinese healthcare workers.
This study will employ two sequential phases. Phase 1 has a cross-sectional exploratory design used to investigate the fit rate and mask usability of three types of respirators. Phase 2 will examine the effectiveness of respiratory protection by comparing traditional and new N95 respirators by a randomized crossover trial. Eligible participants will be randomly allocated through a controlled crossover experiment to either a traditional or new respirator group (n = 100 in each arm) for performing standard clinical procedures. The primary outcome (real-time leakage) will be recorded at 30 s intervals during nasopharyngeal suctioning and cardiopulmonary resuscitation. The secondary outcomes are the fit rate and mask usability. After a 2 min suctioning (15 s twice) and 4 min one-person CPR, the fit rate (assessed by standard N95 fit testing) and mask usability (measured by self-reported mask usability scale) will be recorded as data of post-procedure. After 10 min rest, measurement of real-time leakage (i.e., crossover), fit test, and usability will be repeated.
The result of real-time leakage will be a vital indicator of the respiratory protection of Chinese healthcare workers while performing prevalent clinical procedures, such as resuscitation. The fit rate and usability result will serve as an essential reference for consumable purchase policy in clinical settings.Trial registration: ISRCTN registry: ISRCTN40115047. Retrospectively registered on May 9, 2023. https://www.isrctn.com/ISRCTN40115047.

Former meta-analyses concluded that there was not sufficient evidence to determine the effect of surgical masks and N95 respirators. We collected randomized controlled trials (RCTs) and conducted a systematic review and meta-analysis to evaluate the efficacy of N95 respirators and surgical masks for protection against COVID-19. We retrieved relevant RCTs published between January 2019 and January 2023 by searching the PubMed, EMBASE, and Cochrane CENTRAL. Study quality was evaluated using the Cochrane Risk of Bias tool with the RevMan 5.4 software. Meta-analyses were conducted to calculate pooled estimates using the RevMan 5.4 software. A total of six RCTs were finally included. The findings revealed that wearing a mark made little difference in preventing COVID-19 [odds ratio (OR) = 0.10; 95% confidence interval (CI): 0.01-0.93; P = 0.04]. Subgroup analysis showed that the heterogeneity of data was I2 = 64% (OR = 0.32; 95% CI: 0.06-1.77; P = 0.19) for surgical mask use and I2 = 0% (OR = 0.03; 95 %CI: 0.01-0.15; P < 0.01) for N95 respirator use. The heterogeneity of data for medical staff was I2 = 0% (OR = 0.03; 95 %CI: 0.01-0.12; P < 0.01). Meta-analysis indicated a protective effect of N95 respirators against COVID-19, particularly for medical staff. The use of surgical masks is not associated with a lower risk of COVID-19. However, the subgroup using N95 respirators, particularly medical staff, showed a significant protective. These findings suggest that N95 respirators should be reserved for high-risk medical staff in the absence of sufficient resources during an epidemic. But the number of included studies was small, more studies in future analyses is required to reduce the risk of distribution bias.

OBJECTIVE: to investigate the prevalence of skin lesions and factors associated with the use of N95 respirators among health professionals in Brazil.
METHODS: cross-sectional study conducted with 11,368 health professionals using a respondent-driven sampling method adapted for online environments. Univariate and multivariate analyses were performed to investigate the association between the \"skin lesions with the use of N95 respirators\" variable and gender, professional category, workplace, training, COVID-19 diagnosis, and availability of sufficient and high-quality Personal Protective Equipment.
RESULTS: the prevalence of skin lesions was 61.8%. Women were 1.203 times (95% CI: 1.154-1.255) more likely to develop a lesion than men. The chances of skin lesions in psychologists (PR=0.805; 95% CI: 0.678-0.956) and dentists (PR=0.884; 95% CI: 0.788-0.992), were lower when compared to Nursing professionals. Professionals with a positive COVID-19 diagnosis and working in the Intensive Care Unit have an increased chance of presenting skin lesions (PR=1.074; 95% CI: 1.042-1.107); (PR=1.203; 95% CI: 1.168-1.241), respectively.
CONCLUSIONS: the prevalence of skin lesions caused by the use of N95 respirators was 61.8% and was associated with female gender, professional category, workplace, training, COVID-19 diagnosis, and availability of sufficient and highquality Personal Protective Equipment. (1) The overall prevalence of skin lesions was 61.8%. (2) The most affected professional category was Nursing. (3) Women were more likely to develop skin lesions than men.
OBJECTIVE: investigar la prevalencia de lesiones cutáneas y factores asociados con el uso de respiradores N95 en profesionales de la salud de Brasil.
UNASSIGNED: estudio transversal realizado con 11.368 profesionales de la salud en el que se empleó un método de muestreo dirigido por encuestados adaptado para entornos en línea. Se ejecutaron análisis univariados y multivariados para investigar la asociación entre la variable “lesiones cutáneas por utilizar respiradores N95” y sexo, categoría profesional, lugar de trabajo, capacitación, diagnóstico de COVID-19 y disponibilidad de suficiente provisión de Equipo de Protección Personal de buena calidad.
RESULTS: la prevalencia de lesiones cutáneas fue del 61,8%. Las mujeres fueron 1,203 veces (IC 95%: 1,154-1,255) más propensas a desarrollar lesiones que los hombres. La probabilidad de lesiones cutáneas en psicólogos (RP=0,805; IC 95%: 0,678-0,956) y dentistas (RP=0,884; IC 95%: 0,788-0,992) fue menor en comparación con la encontrada en los profesionales de Enfermería. Los profesionales con diagnóstico positivo de COVID-19 y que trabajan en la Unidad de Cuidados Intensivos son más propensos a sufrir lesiones cutáneas (RP=1,074; IC 95%: 1,042-1,107); (RP=1,203; IC 95%: 1,168-1,241), respectivamente.
UNASSIGNED: la prevalencia de lesiones cutáneas causadas por utilizar respiradores N95 fue del 61,8% y estuvo asociada al sexo femenino, a la categoría profesional, al lugar de trabajo, a la capacitación, a diagnóstico de COVID-19 y a la disponibilidad de suficiente provisión de Equipo de Protección Personal de buena calidad. (1) La prevalencia general de lesiones cutáneas fue del 61,8%. (2) La categoría profesional más afectada fue la de Enfermería. (3) Las mujeres fueron más propensas a desarrollar lesiones cutáneas que los hombres.
OBJECTIVE: investigar a prevalência de lesões de pele e fatores associados ao uso de respiradores N95 entre profissionais de saúde no Brasil.
UNASSIGNED: estudo transversal realizado com 11.368 profissionais de saúde por meio de um método de amostragem dirigido por respondentes adaptado para ambientes online. Análises univariadas e multivariadas foram realizadas para investigar a associação entre a variável “lesão de pele com uso de respirador N95” e sexo, categoria profissional, local de trabalho, treinamento, diagnóstico de COVID-19 e disponibilidade suficiente de equipamentos de proteção individual de qualidade.
RESULTS: a prevalência de lesões cutâneas foi de 61,8%. As mulheres foram 1,203 vezes (IC 95%: 1.154-1.255) mais propensas a desenvolver uma lesão do que os homens. As chances de lesão de pele em psicólogos (RP=0,805; IC 95%: 0,678-0,956) e dentistas (RP=0,884; IC 95%: 0,788-0,992) foram menores quando comparados aos profissionais de Enfermagem. Profissionais com diagnóstico positivo para COVID-19 e que trabalham em Unidade de Cuidados Intensivos têm maior chance de apresentar lesões de pele (RP=1,074; IC 95%: 1,042-1,107); (RP=1,203; IC 95%: 1,168- 1,241), respectivamente.
UNASSIGNED: a prevalência de lesões de pele causadas pelo uso do respirador N95 foi de 61,8% e esteve associada ao sexo feminino, categoria profissional, local de trabalho, treinamento, diagnóstico de COVID-19 e disponibilidade suficiente de equipamentos de proteção individual de qualidade.