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1.
PLoS One ; 17(12): e0278889, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36490277

RESUMO

This study introduces a customized mask retainer to improve the fit performance of surgical masks using various advanced digital techniques. The participant's 3D face scans with and without a surgical mask were taken by using a smartphone. The mask retainer was designed using the 3D face scan data based on the facial anthropometric landmarks. The fitting was inspected and adjusted using the masked face scan data. The retainer was fabricated using a 3D printer. The effectiveness of the retainer on the augmentation of the fit of the surgical mask was tested according to the Chinese Standard (GB 19083-2010). A questionnaire was used to assess the effect of wearing surgical masks with and without retainers and N95 respirators on subjective perception of discomfort. The effectiveness test of the retainer on the augmentation of the fit performance showed a better than 25-fold increase in the overall fit factor, meeting the fit requirement for KN95 respirators in China. The subjective perception of discomfort of wearing N95 was significantly greater than surgical mask with and without retainers. The fit factor results indicated that by using the retainer, the overall fit factors and that of each exercise significantly increased compared to that of the group with the surgical mask alone. And compared with N95, the surgical mask with the retainer significant improved comfort. The surgical mask with the retainer can provide an alternative of personal protective equipment for healthcare workers.


Assuntos
Dispositivos de Proteção Respiratória , Humanos , Máscaras , Respiradores N95 , Pessoal de Saúde , Teste de Materiais
2.
Sci Rep ; 12(1): 19944, 2022 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-36402800

RESUMO

Due to the shortage of personal protective equipment (PPE) during the COVID-19 pandemic, the interest and demand for sterilization devices to reuse PPE has increased. For reuse of face masks, they must be effectively decontaminated of potential infectious agents without compromising its filtration ability during sterilization. In this study, we utilized an atmospheric pressure pulsed dielectric barrier discharge (DBD), combined with nebulized liquid microdroplets to generate plasma-activated mist (PAM). MS2 and T4 bacteriophages were used to conduct the decontamination tests on two types of N95 respirators. Results showed at least a 2-log reduction of MS2 and T4 on N95 respirators treated in one cycle with 7.8% hydrogen peroxide PAM and at least a 3-log reduction treated in 10% hydrogen peroxide PAM. In addition, it was found that there was no significant degradation in filtration efficiency of N95 respirators (3M 1860 and 1804) treated in 10% hydrogen peroxide PAM found after 20 cycles. In terms of re-useability of masks after treatment as determined, it was shown that the elastic straps of 3M 1804 were fragmented after 20 treatment cycles rendering them unusable, while the straps of 3M 1860 were not negatively affected even after 20 disinfection cycles.


Assuntos
COVID-19 , Dispositivos de Proteção Respiratória , Vírus , Humanos , Respiradores N95 , Desinfecção/métodos , Água , Bacteriófago T4 , Peróxido de Hidrogênio , Pandemias
3.
PLoS One ; 17(11): e0277570, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36367887

RESUMO

N95/FFP3 respirators have been critical to protect healthcare workers and their patients from the transmission of COVID-19. However, these respirators are characterised by a limited range of size and geometry, which are often associated with fitting issues in particular sub-groups of gender and ethnicities. This study describes a novel methodology which combines magnetic resonance imaging (MRI) of a cohort of individuals (n = 8), with and without a respirator in-situ, and 3D registration algorithm which predicted the goodness of fit of the respirator. Sensitivity analysis was used to optimise a deformation value for the respirator-face interactions and corroborate with the soft tissue displacements estimated from the MRI images. An association between predicted respirator fitting and facial anthropometrics was then assessed for the cohort.


Assuntos
COVID-19 , Dispositivos de Proteção Respiratória , Humanos , COVID-19/prevenção & controle , Respiradores N95 , Ventiladores Mecânicos , Pessoal de Saúde
4.
Eur Radiol Exp ; 6(1): 50, 2022 10 10.
Artigo em Inglês | MEDLINE | ID: mdl-36210391

RESUMO

BACKGROUND: The use of facemasks is one of the consequences of the coronavirus disease 2019 (COVID-19) pandemic. We used resting-state functional magnetic resonance imaging (fMRI) to search for subtle changes in brain functional connectivity, expected notably related to the high-level salience network (SN) and default mode network (DMN). METHODS: Prospective crossover design resting 3-T fMRI study with/without wearing a tight FFP2/KN95 facemask, including 23 community-dwelling male healthy controls aged 29.9 ± 6.9 years (mean ± standard deviation). Physiological parameters, respiration frequency, and heart rate were monitored. The data analysis was performed using the CONN toolbox. RESULTS: Wearing an FFP2/KN95 facemask did not impact respiration or heart rate but resulted in a significant reduction in functional connectivity between the SN as the seed region and the left middle frontal and precentral gyrus. No difference was found when the DMN, sensorimotor, visual, dorsal attention, or language networks were used as seed regions. In the absence of significant changes of physiological parameter respiration and heart rate, and in the absence of changes in lower-level functional networks, we assume that those subtle modifications are cognitive consequence of wearing facemasks. CONCLUSIONS: The effect of wearing a tight FFP2/KN95 facemask in men is limited to high-level functional networks. Using the SN as seed network, we observed subtle yet significant decreases between the SN and the left middle frontal and precentral gyrus. Our observations suggest that wearing a facemask may change the patterns of functional connectivity with the SN known to be involved in communication, social behavior, and self-awareness.


Assuntos
Encéfalo , COVID-19 , Respiradores N95 , Adulto , Encéfalo/diagnóstico por imagem , Encéfalo/fisiologia , COVID-19/prevenção & controle , Estudos Cross-Over , Humanos , Masculino , Estudos Prospectivos
5.
Artigo em Inglês | MEDLINE | ID: mdl-36294236

RESUMO

We examined whether discretionary use of an N95 mask reduced symptom reporting in wildland firefighters. The study collected data from two Canadian provinces during the 2021 fire season, with each firefighter followed for up to 4 rotations. Participants completed questionnaires on symptoms at the start and end of each rotation, when they reported also on mask use (if any) and completed a task checklist. Eighty firefighters contributed data. Nineteen firefighters were successfully fit-tested for N95 masks to wear whenever they felt conditions justified. Start-of-rotation symptoms reflected total hours firefighting in 2021. Symptoms of eye, nose and throat irritation and cough were more bothersome at the end of rotation. Cough, throat and nose (but not eye) symptoms were reported as significantly less bothersome at the end of rotation by those allocated masks, having allowed for crew type and start-of-rotation symptoms. Among those allocated a mask, use was most frequent during initial attack and least during driving and patrol. Reasons for not wearing included high work difficulty and low comfort. It is concluded that symptoms in wildland firefighters increased with hours of exposure. While provision of an N95 mask reduced symptoms, work is needed to overcome barriers to respiratory protection.


Assuntos
Bombeiros , Exposição Ocupacional , Humanos , Respiradores N95 , Tosse , Canadá/epidemiologia , Sistema Respiratório , Exposição Ocupacional/análise
6.
Appl Environ Microbiol ; 88(19): e0122122, 2022 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-36129288

RESUMO

The objective of this study was to evaluate the effectiveness of UV technology for virus disinfection to allow FFR reuse. UV is a proven decontamination tool for microbial pathogens, including the SARS-CoV-2 virus. Research findings suggest that the impacts of UV-C treatment on FFR material degradation should be confirmed using microbial surrogates in addition to the commonly performed abiotic particle testing. This study used the surrogates, E. coli and MS-2 bacteriophage, as they bracket the UV response of SARS-CoV-2. Lower log inactivation was observed on FFRs than predicted by aqueous-based UV dose-response data for MS-2 bacteriophage and E. coli. In addition, the dose-response curves did not follow the trends commonly observed with aqueous data for E. coli and MS-2. The dose-response curves for the respirators in this study had a semicircle shape, where the inactivation reached a peak and then decreased. This decrease in UV inactivation is thought to be due to the degradation of the fibers of the FFR and allows for more viral and bacterial cells to wash through the layers of the respirator. This degradation phenomenon was observed at UV doses at and above 2,000 mJ/cm2. Results have demonstrated that FFR materials yield various results in terms of effective disinfection in experiments conducted on KN95 and N95 face respirators. The highest inactivation for both surrogates was observed with the KN95 respirator made by Purism, yielding 3 and 2.75 log inactivation for E. coli and MS-2 at UV doses of 1,500 mJ/cm2. The KN95 made by Anboruo yielded the lowest inactivation for MS-2 at 0.75 log when exposed to 1,000 mJ/cm2. To further test the degradation theory, experiments used a collimated beam device to test the hypothesis further that degradation is occurring at and above UV doses of 1,500 mJ/cm2. The experiment aimed to determine the effect of "predosing" a respirator with UV before inoculating the respirator with MS-2. In this test, quantification of the penetrated irradiance value and the ability of each layer to retain MS-2 were quantified. The results of the experiments varied from the intact FFR degradation experiments but displayed some data to support the degradation theory. IMPORTANCE Research suggests degradation of FFR materials at high UV doses is important. There appears to be a peak inactivation dose at approximately 1,500 mJ/cm2. The subsequent dose increases appear to have the reverse effect on inactivation values; these trends have shown true with both the N95 and KN95-Purism respirators.


Assuntos
COVID-19 , Desinfecção , COVID-19/prevenção & controle , Descontaminação/métodos , Desinfecção/métodos , Escherichia coli , Humanos , Respiradores N95 , SARS-CoV-2 , Raios Ultravioleta , Ventiladores Mecânicos
7.
Lima; Perú. Ministerio de Salud. Instituto Nacional de Salud. Centro Nacional de Salud Pública; 1 ed; Set. 2022. 12 p. ilus.(Serie Nota Técnica, 037).
Monografia em Espanhol | LILACS, LIPECS, MINSAPERÚ, INS-PERU | ID: biblio-1402629

RESUMO

La presente publicación describe las recomendaciones internacionales emitidas a la fecha, respecto al uso de mascarillas en la población general y si éstas señalaban usar doble mascarilla, una sola mascarilla o sólo un respirador (KN95 o N95). De la revisión de 11 documentos emitidos por organismos y autoridades sanitarias internacionales, se identificó que tanto el uso de una mascarilla o un respirador (incluyendo N95 o KN95) ha sido incluido en las recomendaciones para su uso en población general. Independientemente del dispositivo, se ha coincidido en que lo fundamental es el uso adecuado del mismo, que se ajuste bien a la cara, que se pueda usar constantemente y esté disponible. Las opciones, en orden descendente de acuerdo al nivel de protección son: respiradores aprobados por NIOSH, respiradores tipo KN95 con buen ajuste, mascarillas quirúrgicas desechables y en último lugar las mascarillas de tela de múltiples capas con buen ajuste y varilla nasal. La OMS, el CDC de Estados Unidos, el CDC de la Unión Europea y el gobierno de Canadá han precisado los estándares que deben ser cumplidos


Assuntos
Padrões de Referência , Ventiladores Mecânicos , Fatores de Proteção , COVID-19 , Máscaras , Respiradores N95
8.
Lima; Perú. Ministerio de Salud. Instituto Nacional de Salud. Centro Nacional de Salud Pública; 1 ed; Set. 2022. 14 p. ilus.(Serie Nota Técnica, 036).
Monografia em Espanhol | LILACS, LIPECS, MINSAPERÚ, INS-PERU | ID: biblio-1402626

RESUMO

La presente publicación describe la evidencia científica disponible respecto a la efectividad y seguridad del uso obligatorio de mascarilla versus en el ámbito escolar, a partir de estudios realizados en instituciones educativas en un contexto de disponibilidad de vacunas. Se reportó una asociación significativa entre escuelas con orden de uso obligatorio de mascarillas y una reducción importante en el número de casos de COVID-19 en estudiantes y trabajadores de las escuelas. Sin embargo, la evidencia procede de cuatro estudios ecológicos, no fue posible determinar el efecto aislado del uso de mascarillas de otras medidas de mitigación y el análisis no tomó en cuenta factores como nivel de adherencia o cumplimiento del mandato, tipo de mascarilla empleada, transmisión en el hogar, los diferentes protocolos para detección de casos en las escuelas incluidas y su capacidad para detectar los casos asintomáticos. Todos los estudios se realizaron en un periodo de disponibilidad de vacunas, en su mayoría para niños de 12 años o más, y previo a la circulación de la variante Omicron. Un análisis secundario identificó que la mayor intensidad de la transmisión comunitaria, mayor nivel de individualismo de la población y el nivel de educación secundaria en comparación a nivel pre-escolar, se asociaron con un incremento del riesgo de infección en las escuelas. El riesgo disminuyó con la aplicación de medidas preventivas únicas (distanciamiento físico o uso de mascarillas) o combinadas (distanciamiento físico y uso de mascarillas) versus ninguna medida y con el aumento en la inmunidad de la población. Respecto a los efectos psicosociales y en la comunicación, los resultados de 6 estudios fueron heterogéneos. No se encontró un efecto importante en la capacidad de los niños para inferir las emociones a partir de rostros con mascarillas, no hubo diferencias en el rendimiento cognitivo cuando los niños estuvieron expuestos previamente al uso de mascarillas frente a los que no la usaron y la comprensión del lenguaje fue similar cuando el orador usaba o no la mascarilla, en ausencia de ruido. Por otro lado, se evidenció un menor desempeño en la capacidad de reconocimiento facial y una alteración en el procesamiento de los rostros que usaban una mascarilla.


Assuntos
Segurança , Transmissão de Doença Infecciosa , Ensino Fundamental e Médio , Absenteísmo , Reconhecimento Facial , Distanciamento Físico , Respiradores N95 , COVID-19 , Mitigação em Desastres , Imunidade , Máscaras
9.
PLoS One ; 17(8): e0272834, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36001554

RESUMO

BACKGROUND: The COVID-19 pandemic has infected hundreds of millions of people resulting in millions of deaths worldwide. While N95 respirators remain the gold standard as personal protective equipment, they are resource-intensive to produce and obtain. Surgical masks, easier to produce and obtain, filter ≥95% submicron particles but are less protective due to a lack of seal around a user's face. This study tested the ability of a simple surgical mask modification using rubber bands to create a seal against particle exposure that would pass N95 standards. METHODS AND FINDINGS: Forty healthcare workers underwent TSI PortaCount mask fit testing using an ASTM Level 1 surgical mask modified with rubber bands. Fit Factor was determined after testing four standard OSHA N95 fit testing scenarios. Performance of the properly-modified surgical mask was compared to that of a poorly-modified surgical mask, an unmodified standard surgical mask, and an N95 respirator. Thirty-one of forty (78%) healthcare workers passed Fit Factor testing using a properly-modified mask. The Fit Factor success rate significantly improved by subsequent test date (p = 0.043), but was not associated with any other participant characteristics. The average Fit Factor score for the properly-modified mask was 151 (SD 65.2), a significantly better fit than the unmodified mask score of 3.8 (SD 3.1, p<0.001) and the poorly-modified mask score of 24.6 (SD 48.4, p<0.001) but significantly lower than a properly fitted N95 score of 199 (SD 4.5, p<0.001).do. CONCLUSIONS: Rubber bands, a low-cost and easily-accessible modification, can improve the seal and protective ability of a standard surgical mask to the level of an N95 respirator. This could mitigate N95 respirator shortages worldwide and provide individuals in under-resourced regions a practical means for increased personal respiratory protection.


Assuntos
COVID-19 , Exposição Ocupacional , Dispositivos de Proteção Respiratória , COVID-19/epidemiologia , COVID-19/prevenção & controle , Humanos , Máscaras , Respiradores N95 , Exposição Ocupacional/prevenção & controle , Pandemias/prevenção & controle
10.
mSphere ; 7(5): e0030322, 2022 10 26.
Artigo em Inglês | MEDLINE | ID: mdl-36040048

RESUMO

In response to the demand for N95 respirators by health care workers during the COVID-19 pandemic, we evaluated decontamination of N95 respirators using an aerosolized hydrogen peroxide (aHP) system. This system is designed to dispense a consistent atomized spray of aerosolized, 7% hydrogen peroxide (H2O2) solution over a treatment cycle. Multiple N95 respirator models were subjected to 10 or more cycles of respirator decontamination, with a select number periodically assessed for qualitative and quantitative fit testing. In parallel, we assessed the ability of aHP treatment to inactivate multiple viruses absorbed onto respirators, including phi6 bacteriophage, herpes simplex virus 1 (HSV-1), coxsackievirus B3 (CVB3), and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). For pathogens transmitted via respiratory droplets and aerosols, it is critical to address respirator safety for reuse. This study provided experimental validation of an aHP treatment process that decontaminates the respirators while maintaining N95 function. External National Institute for Occupational Safety & Health (NIOSH) certification verified respirator structural integrity and filtration efficiency after 10 rounds of aHP treatment. Virus inactivation by aHP was comparable to the decontamination of commercial spore-based biological indicators. These data demonstrate that the aHP process is effective, with successful fit-testing of respirators after multiple aHP cycles, effective decontamination of multiple virus species, including SARS-CoV-2, successful decontamination of bacterial spores, and filtration efficiency maintained at or greater than 95%. While this study did not include extended or clinical use of N95 respirators between aHP cycles, these data provide proof of concept for aHP decontamination of N95 respirators before reuse in a crisis-capacity scenario. IMPORTANCE The COVID-19 pandemic led to unprecedented pressure on health care and research facilities to provide personal protective equipment. The respiratory nature of the SARS-CoV2 pathogen makes respirator facepieces a critical protective measure to limit inhalation of this virus. While respirator facepieces were designed for single use and disposal, the pandemic increased overall demand for N95 respirators, and corresponding manufacturing and supply chain limitations necessitated the safe reuse of respirators when necessary. In this study, we repurposed an aerosolized hydrogen peroxide (aHP) system that is regularly utilized to decontaminate materials in a biosafety level 3 (BSL3) facility, to develop a method for decontamination of N95 respirators. Results from viral inactivation, biological indicators, respirator fit testing, and filtration efficiency testing all indicated that the process was effective at rendering N95 respirators safe for reuse. This proof-of-concept study establishes baseline data for future testing of aHP in crisis-capacity respirator-reuse scenarios.


Assuntos
COVID-19 , Respiradores N95 , Humanos , COVID-19/prevenção & controle , Pandemias/prevenção & controle , Peróxido de Hidrogênio/farmacologia , SARS-CoV-2 , Inativação de Vírus , Descontaminação/métodos , Estudos de Viabilidade , RNA Viral , Reutilização de Equipamento
11.
Indoor Air ; 32(8): e13088, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-36040272

RESUMO

Wearing surgical or N95 masks is effective in reducing the infection risks of airborne infectious diseases. However, in the literature there are no detailed boundary conditions for airflow from a cough when a surgical or N95 mask is worn. These boundary conditions are essential for accurate prediction of exhaled particle dispersion by computational fluid dynamics (CFD). This study first constructed a coughing manikin with an exhalation system to simulate a cough from a person. The smoke visualization method was used to measure the airflow profile from a cough. To validate the setup of the coughing manikin, the results were compared with measured data from subject tests reported in the literature. The validated coughing manikin was then used to measure the airflow boundary conditions for a cough when a surgical mask was worn and when an N95 mask was worn, respectively. Finally, this study applied the developed airflow boundary conditions to calculate person-to-person particle transport from a cough when masks are worn. The calculated exhaled particle patterns agreed well with the smoke pattern in the visualization experiments. Furthermore, the calculated results indicated that, when the index person wore a surgical and a N95 mask, the total exposure of the receptor was reduced by 93.0% and 98.8%, respectively.


Assuntos
Poluição do Ar em Ambientes Fechados , Expiração , Tosse , Humanos , Respiradores N95
12.
Cogn Res Princ Implic ; 7(1): 73, 2022 07 30.
Artigo em Inglês | MEDLINE | ID: mdl-35907167

RESUMO

Mask-wearing during the COVID-19 pandemic has prompted a growing interest in the functional impact of masks on speech and communication. Prior work has shown that masks dampen sound, impede visual communication cues, and reduce intelligibility. However, more work is needed to understand how speakers change their speech while wearing a mask and to identify strategies to overcome the impact of wearing a mask. Data were collected from 19 healthy adults during a single in-person session. We investigated the effects of wearing a KN95 mask on speech intelligibility, as judged by two speech-language pathologists, examined speech kinematics and acoustics associated with mask-wearing, and explored KN95 acoustic filtering. We then considered the efficacy of three speaking strategies to improve speech intelligibility: Loud, Clear, and Slow speech. To inform speaker strategy recommendations, we related findings to self-reported speaker effort. Results indicated that healthy speakers could compensate for the presence of a mask and achieve normal speech intelligibility. Additionally, we showed that speaking loudly or clearly-and, to a lesser extent, slowly-improved speech intelligibility. However, using these strategies may require increased physical and cognitive effort and should be used only when necessary. These results can inform recommendations for speakers wearing masks, particularly those with communication disorders (e.g., dysarthria) who may struggle to adapt to a mask but can respond to explicit instructions. Such recommendations may further help non-native speakers and those communicating in a noisy environment or with listeners with hearing loss.


Assuntos
COVID-19 , Transtornos da Comunicação , Adulto , COVID-19/prevenção & controle , Cognição , Humanos , Máscaras , Respiradores N95 , Pandemias , Inteligibilidade da Fala
13.
Rev Bras Enferm ; 75(6): e20210412, 2022.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-35858026

RESUMO

OBJECTIVE: To identify the factors associated with the use of the N95 respirator in Nursing and Medical students in the daily life of the covid-19 pandemic. METHODS: Descriptive-analytical cross-sectional study carried out in 2020. A total of 830 students from three universities in Peru participated in the study. Associations were evaluated using Pearson's Chi-Square and multivariate Poisson modeling with log linkage. RESULTS: Statistically significant differences were found between the preference to use the N95 respirator in relation to masks according to the activity they perform (p=0.001) and where they live (p=0.005). The multivariate analysis reported that the associated characteristics were age, activity performed, perception and fear of being infected by covid-19. CONCLUSION: The choice of N95 respirator is influenced by individual factors and perceptions. Spaces are needed to discuss daily life, the way of living, caring and educating, considering the socioeconomic dimensions and beliefs.


Assuntos
COVID-19 , COVID-19/prevenção & controle , Estudos Transversais , Humanos , Respiradores N95 , Pandemias/prevenção & controle , SARS-CoV-2 , Estudantes , Universidades
14.
Artigo em Inglês | MEDLINE | ID: mdl-35805244

RESUMO

This study compared exercise performance and comfort while wearing an N95 filtering facepiece respirator (N95), cloth mask, or no intervention control for source control during a maximal graded treadmill exercise test (GXT). Twelve Division 1 athletes (50% female, age = 20.1 ± 1.2, BMI = 23.5 ± 1.6) completed GXTs under three randomized conditions (N95, cloth mask, control). GXT duration, heart rate (HR), respiration rate (RR), transcutaneous oxygen saturation (SpO2), transcutaneous carbon dioxide (TcPCO2), rating of perceived exertion (RPE), and perceived comfort were measured. Participants ran significantly longer in control (26.06 min) versus N95 (24.20 min, p = 0.03) or cloth masks (24.06 min, p = 0.04). No differences occurred in the slope of HR or SpO2 across conditions (p > 0.05). TcPCO2 decreased faster in control (B = -0.89) versus N95 (B = 0.14, p = 0.02) or cloth masks (B = -0.26, p = 0.03). RR increased faster in control (B = 8.32) versus cloth masks (B = 6.20, p = 0.04). RPE increased faster in the N95 (B = 1.91) and cloth masks (B = 1.79) versus control (B = 1.59, p < 0.001 and p = 0.05, respectively). Facial irritation/itching/pinching was higher in the N95 versus cloth masks, but sweat/moisture buildup was lower (p < 0.05 for all). Wearing cloth masks or N95s for source control may impact exercise performance, especially at higher intensities. Significant physiological differences were observed between cloth masks and N95s compared to control, while no physiological differences were found between cloth masks and N95s; however, comfort my differ.


Assuntos
Máscaras , Respiradores N95 , Adolescente , Adulto , Atletas , Exercício Físico , Teste de Esforço , Feminino , Humanos , Masculino , Adulto Jovem
15.
Artigo em Inglês | MEDLINE | ID: mdl-35886496

RESUMO

During the COVID-19 pandemic, N95 respirators were commonly used in many situations. Respiratory problems from prolonged use of respirators were discussed in many studies, which show varied results. From the inconclusive results, the current systematic review and meta-analysis discerned the effects of the N95 respirator by assessing the oxygen and carbon dioxide changes in both high- and low-to-moderate-intensity physical activities in a healthy population. Thirteen studies were identified for inclusion in the study. In high-intensity physical activities, our meta-analysis showed borderline lower oxygen saturation and higher carbon dioxide partial pressure, but oxygen saturation did not change in low-to-moderate physical activity. The use of N95 respirators could statistically affect the physiologic changes of carbon dioxide and oxygen in high-intensity physical activity among healthy participants, but this may not be clinically significant. Some users who have certain health conditions, such as respiratory problems, should be informed of the clinical symptoms related to hypercarbia and hypoxia for the early detection of adverse effects of N95 respirators.


Assuntos
COVID-19 , Dispositivos de Proteção Respiratória , COVID-19/prevenção & controle , Dióxido de Carbono , Humanos , Respiradores N95 , Oxigênio , Pandemias/prevenção & controle
16.
Am J Infect Control ; 50(8): 857-862, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35908823

RESUMO

BACKGROUND: Global shortage of personal protective equipment (PPE), as consequence of the COVID-19 global pandemic, has unmasked significant resource inequities prompting efforts to develop methods for safe PPE decontamination for reuse. The World Health Organization (WHO) in their Rational Use of PPE bulletin cited the use of a photodynamic dye, methylene blue, and light exposure as a viable option for N95 respirator decontamination. Because WHO noted that methylene blue (MB) would be applied to surfaces through which health care workers breathe, we hypothesized that little to no MB will be detectable by spectroscopy when the PPE is subjected to MB at supraphysiologic airflow rates. METHODS: A panel of N95 respirators, medical masks, and cloth masks were sprayed with 5 cycles of 1,000 uM MB solution. Mask coupons were subjected to the equivalent of 120 L/min of 100% humidified air flow. Effluent gas was trapped in an aqueous solution and the resultant fluid was sampled for MB absorbance with a level of detection of 0.004 mg/m3. RESULTS: No detectable MB was identified for any mask using Ultraviolet-Visible spectroscopy. CONCLUSIONS: At 500-fold the amount of MB applied to N95 respirators and medical masks as were used for the decontamination study cited in the WHO Rational Use of PPE bulletin, no detectable MB was observed, thus providing safety evidence for the use of methylene blue and light exposure for mask decontamination.


Assuntos
COVID-19 , SARS-CoV-2 , COVID-19/prevenção & controle , Descontaminação/métodos , Reutilização de Equipamento , Humanos , Azul de Metileno , Respiradores N95
17.
Am J Infect Control ; 50(8): 863-870, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35908824

RESUMO

BACKGROUND: The COVID-19 pandemic resulted in a worldwide shortage of N95 respirators, prompting the development of decontamination methods to enable limited reuse. Countries lacking reliable supply chains would also benefit from the ability to safely reuse PPE. Methylene blue (MB) is a light-activated dye with demonstrated antimicrobial activity used to sterilize blood plasma. Decontamination of respirators using photoactivated MB requires no specialized equipment, making it attractive for use in the field during outbreaks. METHODS: We examined decontamination of N95 and KN95 respirators using photoactivated MB and 3 variants of SARS-CoV-2, the virus that causes COVID-19; and 4 World Health Organization priority pathogens: Ebola virus, Middle East respiratory syndrome coronavirus, Nipah virus, and Lassa virus. Virus inactivation by pretreating respirator material was also tested. RESULTS: Photoactivated MB inactivated all tested viruses on respirator material, albeit with varying efficiency. Virus applied to respirator material pre-treated with MB was also inactivated, thus MB pretreatment may potentially protect respirator wearers from virus exposure in real-time. CONCLUSIONS: These results demonstrate that photoactivated MB represents a cost-effective, rapid, and widely deployable method to decontaminate N95 respirators for reuse during supply shortages.


Assuntos
COVID-19 , Doença pelo Vírus Ebola , Coronavírus da Síndrome Respiratória do Oriente Médio , Vírus Nipah , COVID-19/prevenção & controle , Descontaminação/métodos , Reutilização de Equipamento , Doença pelo Vírus Ebola/prevenção & controle , Humanos , Azul de Metileno/farmacologia , Respiradores N95 , Pandemias/prevenção & controle , SARS-CoV-2 , Ventiladores Mecânicos
18.
Photochem Photobiol Sci ; 21(11): 1915-1929, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35864345

RESUMO

As part of efforts to combat the Covid-19 pandemic and decrease the high transmissibility of the new coronavirus, SARS-CoV-2, effective inactivation strategies, such as UV-C decontamination technologies, can be reliably disseminated and well-studied. The present study investigated the susceptibility of a high viral load of SARS-CoV-2 in filtering facepiece respirators (FFR) N95, surgical mask, cotton fabric mask and N95 straps under three different doses of UV-C, applying both real-time PCR (qPCR) and plaque formation assays to quantify viral load reduction and virus infectivity, respectively. The results show that more than 95% of the amount of SARS-CoV-2 RNA could be reduced after 10 min of UV-C exposure (0.93 J cm-2 per side) in FFR N95 and surgical masks and, after 5 min of UV-C treatment (0.46 J cm-2 per side) in fabric masks. Furthermore, the analysis of viable coronaviruses after these different UV-C treatments demonstrated that the lowest applied dose is sufficient to decontaminate all masks ([Formula: see text] 3-log10 reduction of the infective viral load, > 99.9% reduction). However, for the elastic strap of N95 respirators, a UV-C dose three times greater than that used in masks (1.4 J cm-2 per side) is required. The findings suggest that the complete decontamination of masks can be performed effectively and safely in well-planned protocols for pandemic crises or as strategies to reduce the high consumption and safe disposal of these materials in the environment.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , Pandemias , Máscaras , Respiradores N95 , COVID-19/prevenção & controle , RNA Viral , Descontaminação/métodos
19.
J Hosp Infect ; 127: 91-100, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35792275

RESUMO

BACKGROUND: Aerosol-borne diseases such as COVID-19 may outbreak occasionally in various regions of the world, inevitably resulting in short-term shortage and corresponding reuse of disposable respirators. AIM: To investigate the effective disinfection methods, reusable duration and frequency of N95 respirators. METHODS: Based on the self-built respirator simulation test system, and under combinations of experimental conditions of three N95 respirators × 0-200 nm NaCl aerosols × three simulated breathing flow rates (15, 50 and 85 L/min) × two disinfection methods (dry heating and ultraviolet (UV) radiation), this study continuously measured the changes in filtration efficiency of all respirators during multi-cycles of '8-h simulated donning + disinfection' until the penetration reached ≥5%. FINDINGS: Multi-cycles of dry heating and UV radiation treatments on the reused (i.e., multiple 8-h donning) N95 respirators had a minimal effect (<0.5%) on the respirator filtration efficiency, and even at 85 L/min, all tested N95 respirators were able to maintain filtration efficiencies ≥95% for at least 30 h or four reuse cycles of '8-h donning + disinfection', while a lower breathing flow rate (15 L/min) plus the exhalation valve could further extend the N95 respirator's usability duration up to 140 h or 18 reuse cycles of '8-h donning + disinfection'. As the respirator wearing time extended, aerosol penetration slowly increased in a quadratic function with a negative second-order coefficient, and the penetration increment during each cycle of 8-h donning was less than 0.9%. CONCLUSION: Multi-cycles of N95 respirator reuse in combination with dry heating or UV irradiation disinfection are feasible.


Assuntos
COVID-19 , Dispositivos de Proteção Respiratória , COVID-19/prevenção & controle , Desinfecção/métodos , Filtração , Humanos , Respiradores N95 , Aerossóis e Gotículas Respiratórios
20.
J Occup Environ Hyg ; 19(9): 580-589, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35819354

RESUMO

This study focuses on reprocessing a group of filtering facepiece respirators (FFR) using ultraviolet germicidal irradiation (UVGI). The aim is to explore the possibility of disinfecting selected KN95 FFRs, in comparison with the N95 FFRs, and assess their viability for reusage. For this purpose, five models of unused N95 and KN95 FFR models obtained from the hospital were exposed to UV-C light using a customized UVGI chamber. The material integrity of treated FFRs was examined in terms of particle penetration and strap tension. The surface morphology of all models is inspected to determine the visible changes of each FFR upon exposure to 1-100 cycles (1 cycle is equivalent to 1 J/cm2 UV dose). The penetration test results indicate that the physical properties of the KN95 and N95 FFRs remain within permissible limits despite being reprocessed by up to 100 cycles (100 J/cm2). Using a microscope, the physical observations also reveal that no visible damage can be seen even after 100 J/cm2 exposure. Apart from the filter bodies, the tension of each strap was also found to not be significantly affected by UV radiation by at least 10 disinfection cycles (10 J/cm2). This confirms that KN95, as well as N95 FFRs, can be subjected to UV treatment as a means of disinfection.


Assuntos
Dispositivos de Proteção Respiratória , Raios Ultravioleta , Desinfecção/métodos , Reutilização de Equipamento , Respiradores N95 , Ventiladores Mecânicos
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