scholarly journals Airborne Transmission of Virus-Laden Aerosols inside a Music Classroom: Effects of Portable Purifiers and Aerosol Injection Rates

2020 ◽  
Author(s):  
Sai Ranjeet Narayanan ◽  
Suo Yang
Keyword(s):  
Aerosol Deposition ◽  
Injection Rate ◽  
Musical Instruments ◽  
World Health ◽  
Indoor Environments ◽  
Airborne Transmission ◽  
Classroom Effects ◽  
Airborne Concentration ◽  
Health Organization ◽  
Injection Rates

The ongoing COVID-19 pandemic has shifted attention to the airborne transmission of exhaled droplet nuclei within indoor environments. The spread of aerosols through singing and musical instruments in music performances has necessitated precautionary methods such as masks and portable purifiers. This study investigates the effects of placing portable air purifiers at different locations inside a classroom, as well as the effects of different aerosol injection rates (e.g., with and without masks, different musical instruments and different injection modes). Aerosol deposition, airborne concentration and removal are analyzed in this study. It was found that using purifiers could help in achieving ventilation rates close to the prescribed values by the World Health Organization (WHO), while also achieving aerosol removal times within the Center of Disease Control and Prevention (CDC) recommended guidelines. This could help in deciding break periods between classroom sessions, which was around 25 minutes through this study. Moreover, proper placement of purifiers could offer significant advantages in reducing airborne aerosol numbers (offering orders of magnitude higher aerosol removal when compared to nearly zero removal when having no purifiers), and improper placement of the purifiers could worsen the situation. The study suggests the purifier to be placed close to the injector to yield a benefit, and away from the people to be protected. The injection rate was found to have an almost linear correlation with the average airborne aerosol suspension rate and deposition rate, which could be used to predict the trends for scenarios with other injection rates.

scholarly journals A convolution neural network approach for fall detection based on adaptive channel selection of UWB radar signals

2022 ◽  
Author(s):  
Ping Wang ◽  
Qimeng Li ◽  
Peng Yin ◽  
Zhonghao Wang ◽  
Yu Ling ◽  
...  
Keyword(s):  
Neural Network ◽  
Fall Detection ◽  
The Elderly ◽  
Channel Selection ◽  
Ultra Wideband ◽  
World Health ◽  
Indoor Environments ◽  
Neural Network Approach ◽  
High Recognition Accuracy ◽  
Health Organization

AbstractAccording to the World Health Organization and other authorities, falls are one of the main causes of accidental injuries among the elderly population. Therefore, it is essential to detect and predict the fall activities of older persons in indoor environments such as homes, nursing, senior residential centers, and care facilities. Due to non-contact and signal confidentiality characteristics, radar equipment is widely used in indoor care, detection, and rescue. This paper proposes an adaptive channel selection algorithm to separate the activity signals from the background using an ultra-wideband radar and to generalize fused features of frequency- and time-domain images which will be sent to a lightweight convolutional neural network to detect and recognize fall activities. The experimental results show that the method is able to distinguish three types of fall activities (i.e., stand to fall, bow to fall, and squat to fall) and obtain a high recognition accuracy up to 95.7%.

scholarly journals Airborne Transmission Route of COVID-19: Why 2 Meters/6 Feet of Inter-Personal Distance Could Not Be Enough

2020 ◽  
Vol 17 (8) ◽  
pp. 2932 ◽  
Author(s):  
Leonardo Setti ◽  
Fabrizio Passarini ◽  
Gianluigi De Gennaro ◽  
Pierluigi Barbieri ◽  
Maria Grazia Perrone ◽  
...  
Keyword(s):  
Virus Transmission ◽  
Field Studies ◽  
University Hospital ◽  
World Health ◽  
Indoor Environments ◽  
Airborne Transmission ◽  
Surface Stability ◽  
Air Samples ◽  
Daily Life Activities ◽  
The World

The COVID-19 pandemic caused the shutdown of entire nations all over the world. In addition to mobility restrictions of people, the World Health Organization and the Governments have prescribed maintaining an inter-personal distance of 1.5 or 2 m (about 6 feet) from each other in order to minimize the risk of contagion through the droplets that we usually disseminate around us from nose and mouth. However, recently published studies support the hypothesis of virus transmission over a distance of 2 m from an infected person. Researchers have proved the higher aerosol and surface stability of SARS-COV-2 as compared with SARS-COV-1 (with the virus remaining viable and infectious in aerosol for hours) and that airborne transmission of SARS-CoV can occur besides close-distance contacts. Indeed, there is reasonable evidence about the possibility of SARS-COV-2 airborne transmission due to its persistence into aerosol droplets in a viable and infectious form. Based on the available knowledge and epidemiological observations, it is plausible that small particles containing the virus may diffuse in indoor environments covering distances up to 10 m from the emission sources, thus representing a kind of aerosol transmission. On-field studies carried out inside Wuhan Hospitals showed the presence of SARS-COV-2 RNA in air samples collected in the hospitals and also in the surroundings, leading to the conclusion that the airborne route has to be considered an important pathway for viral diffusion. Similar findings are reported in analyses concerning air samples collected at the Nebraska University Hospital. On March 16th, we have released a Position Paper emphasizing the airborne route as a possible additional factor for interpreting the anomalous COVID-19 outbreaks in northern Italy, ranked as one of the most polluted areas in Europe and characterized by high particulate matter (PM) concentrations. The available information on the SARS-COV-2 spreading supports the hypothesis of airborne diffusion of infected droplets from person to person at a distance greater than two meters (6 feet). The inter-personal distance of 2 m can be reasonably considered as an effective protection only if everybody wears face masks in daily life activities.

scholarly journals Relationships between Exposure to Bioaerosols, Moldy Surface and Symptoms in French Mold-Damaged Homes

Atmosphere ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 223
Author(s):  
Antoine Delanoë ◽  
Natacha Heutte ◽  
Stéphanie Gente ◽  
Virginie Séguin ◽  
David Garon
Keyword(s):  
Air Quality ◽  
Indoor Air ◽  
Economic Consequences ◽  
World Health ◽  
Aspergillus Versicolor ◽  
Mold Growth ◽  
Global Approach ◽  
Airborne Concentration ◽  
The World ◽  
Health Organization

Air quality in homes is a major concern in Europe, where people spend most of their time indoors. According to the World Health Organization, numerous houses are subject to dampness that can lead to mold growth, with associated health and economic consequences. Our goal was to characterize the human exposure to bioaerosols in French mold-damaged houses but also to study the effects of these bioaerosols as suffered by the inhabitants of these houses. A global approach including both field study and laboratory experimentation was used to investigate 48 mold-damaged homes. Among a wide fungal diversity, 101 viable species, Aspergillus versicolor, Penicillium chrysogenum and P. crustosum were observed as recurrent species and could be used as microbial indicators of indoor air quality. Statistical analyses highlighted a relationship between the concentrations of these recurrent molds and the levels of surface contamination by molds in homes. Fever, cough, dyspnea, flu-like symptoms were observed with several fungal strains (A. versicolor, P. chrysogenum and P. crustosum) or in relation to moldy odor. Relationships between particles of 2 to 15 µm diameter and headaches and dizziness were also observed. In our study, we identified a cutaneous effect (itching) in relationship to the airborne concentration of A. versicolor.

Obstacles to Claiming Permanence and Injury-Relatedness for “Posttraumatic” Headache

2009 ◽  
Vol 14 (3) ◽  
pp. 3-6
Author(s):  
Robert J. Barth
Keyword(s):  
Complete Recovery ◽  
World Health ◽  
Related Factors ◽  
Posttraumatic Headache ◽  
Sixth Edition ◽  
Causative Relationship ◽  
Short Period ◽  
The One ◽  
Health Organization ◽  
Subjective Reports

Abstract “Posttraumatic” headaches claims are controversial because they are subjective reports often provided in the complex of litigation, and the underlying pathogenesis is not defined. This article reviews principles and scientific considerations in the AMAGuides to the Evaluation of Permanent Impairment (AMA Guides) that should be noted by evaluators who examine such cases. Some examples in the AMA Guides, Sixth Edition, may seem to imply that mild head trauma can cause permanent impairment due to headache. The author examines scientific findings that present obstacles to claiming that concussion or mild traumatic brain injury is a cause of permanent headache. The World Health Organization, for example, found a favorable prognosis for posttraumatic headache, and complete recovery over a short period of time was the norm. Other studies have highlighted the lack of a dose-response correlation between trauma and prolonged headache complaints, both in terms of the frequency and the severity of trauma. On the one hand, scientific studies have failed to support the hypothesis of a causative relationship between trauma and permanent or prolonged headaches; on the other hand, non–trauma-related factors are strongly associated with complaints of prolonged headache.

Sixth Edition: the New Standard

2008 ◽  
Vol 13 (1) ◽  
pp. 1-12
Author(s):  
Christopher R. Brigham ◽  
Robert D. Rondinelli ◽  
Elizabeth Genovese ◽  
Craig Uejo ◽  
Marjorie Eskay-Auerbach
Keyword(s):  
Review Process ◽  
Peer Review Process ◽  
World Health ◽  
International Classification Of Functioning ◽  
Revision Process ◽  
Sixth Edition ◽  
Impairment Ratings ◽  
Health Organization ◽  
Impairment Severity

Abstract The AMA Guides to the Evaluation of Permanent Impairment (AMA Guides), Sixth Edition, was published in December 2007 and is the result of efforts to enhance the relevance of impairment ratings, improve internal consistency, promote precision, and simplify the rating process. The revision process was designed to address shortcomings and issues in previous editions and featured an open, well-defined, and tiered peer review process. The principles underlying the AMA Guides have not changed, but the sixth edition uses a modified conceptual framework based on the International Classification of Functioning, Disability, and Health (ICF), a comprehensive model of disablement developed by the World Health Organization. The ICF classifies domains that describe body functions and structures, activities, and participation; because an individual's functioning and disability occur in a context, the ICF includes a list of environmental factors to consider. The ICF classification uses five impairment classes that, in the sixth edition, were developed into diagnosis-based grids for each organ system. The grids use commonly accepted consensus-based criteria to classify most diagnoses into five classes of impairment severity (normal to very severe). A figure presents the structure of a typical diagnosis-based grid, which includes ranges of impairment ratings and greater clarity about choosing a discreet numerical value that reflects the impairment.

The Historical Development of Burden of Treatment Compliance

2014 ◽  
Vol 19 (5) ◽  
pp. 13-15
Author(s):  
Stephen L. Demeter
Keyword(s):  
Internal Medicine ◽  
Treatment Compliance ◽  
World Health ◽  
International Classification Of Functioning ◽  
Sixth Edition ◽  
Burden Of Treatment ◽  
Specific Goal ◽  
Surrogate Measure ◽  
Health Organization

Abstract A long-standing criticism of the AMA Guides to the Evaluation of Permanent Impairment (AMA Guides) has been the inequity between the internal medicine ratings and the orthopedic ratings; in the comparison, internal medicine ratings appear inflated. A specific goal of the AMA Guides, Sixth Edition, was to diminish, where possible, those disparities. This led to the use of the International Classification of Functioning, Disability, and Health from the World Health Organization in the AMA Guides, Sixth Edition, including the addition of the burden of treatment compliance (BOTC). The BOTC originally was intended to allow rating internal medicine conditions using the types and numbers of medications as a surrogate measure of the severity of a condition when other, more traditional methods, did not exist or were insufficient. Internal medicine relies on step-wise escalation of treatment, and BOTC usefully provides an estimate of impairment based on the need to be compliant with treatment. Simplistically, the need to take more medications may indicate a greater impairment burden. BOTC is introduced in the first chapter of the AMA Guides, Sixth Edition, which clarifies that “BOTC refers to the impairment that results from adhering to a complex regimen of medications, testing, and/or procedures to achieve an objective, measurable, clinical improvement that would not occur, or potentially could be reversed, in the absence of compliance.

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