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Objectives: This study aimed to assess indoor air quality (IAQ) in long-term care facilities (LTCFs) in California during the COVID-19 pandemic and evaluate their implementation of IAQ best practices described by public health authorities to control respiratory pathogen transmission via inhalation., Design: This observational study conducted IAQ assessments in a convenience sample of LTCFs to gather qualitative data on the implementation of IAQ best practices. The design included 5 pilot visits to develop a standardized method of data collection and then systematic data collection at 10 facilities., Setting and Participants: The study focused on 10 LTCFs across California, chosen from facilities that responded to flyers advertising free IAQ assessments. Some of the facilities had previously experienced COVID-19 outbreaks affecting residents and staff., Methods: State health department industrial hygienists performed site visits to collect data on each facility's heating, ventilation, and air-conditioning (HVAC) system operation, outdoor air introduction, recirculated air filtration, use of portable air cleaners, and directional airflow in isolation areas to evaluate implementation of IAQ best practices in each of these areas. Qualitative data were obtained through visual inspections and interviews with maintenance personnel., Results: Findings indicated suboptimal implementation of IAQ best practices across the assessed facilities: no facility operated HVAC systems continuously, 40% had all outdoor air dampers open, 20% used MERV-13 or higher rated filters, 20% used portable air cleaners, and 20% performed directional airflow assessment and management for isolating COVID-19 cases., Conclusions and Implications: Most LTCFs assessed were not adhering to IAQ best practices, highlighting a significant opportunity for improvement. IAQ best practices described in this study are achievable with existing systems and are critical for reducing virus transmission through the air in LTCFs. The findings underscore the need for more systematic assessments and improvements in IAQ within LTCFs to protect staff and residents., Competing Interests: Disclosure The authors declare no conflicts of interest., (Copyright © 2024 Post-Acute and Long-Term Care Medical Association. Published by Elsevier Inc. All rights reserved.)

Indoor air quality (IAQ) and indoor air pollution are critical issues impacting urban environments, significantly affecting the quality of life. Nowadays, poor IAQ is linked to respiratory and cardiovascular diseases, allergic reactions, and cognitive impairments, particularly in settings like classrooms. Thus, this study investigates the impact of indoor environmental quality on student health in a university classroom over a year, using various sensors to measure 19 environmental parameters, including temperature, relative humidity, CO 2 , CO, volatile organic compounds (VOCs), particulate matter (PM), and other pollutants. Thus, the aim of the study is to analyze the implications of the indoor microclimate for the health of individuals working in the classroom, as well as its implications for educational outcomes. The data revealed frequent exceedances of international standards for formaldehyde (HCHO), VOC, PM 2.5 , NO, and NO 2 . HCHO and VOCs levels, often originating from building materials and classroom activities, were notably high. PM 2.5 levels exceeded both annual and daily standards, while NO and NO 2 levels, possibly influenced by inadequate ventilation, also surpassed recommended limits. Even though there were numerous exceedances of current international standards, the indoor microclimate quality index (IMQI) score indicated a generally good indoor environment, remaining mostly between 0 and 50 for this indicator. Additionally, analyses indicate a high probability that some indicators will exceed the current standards, and their values are expected to trend upwards in the future. The study highlighted the need for better ventilation and pollutant control in classrooms to ensure a healthy learning environment. Frequent exceedances of pollutant standards can suggest a significant impact on student health and academic performance. Thus, the present study underscored the importance of continuous monitoring and proactive measures to maintain optimal indoor air quality., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Caciora, Ilieş, Berdenov, Al-Hyari, Ilieş, Safarov, Hassan, Herman, Hodor, Bilalov and Peres.)

Background: The importance of building ventilation to protect health has been more widely recognized since the COVID-19 pandemic. Outdoor air ventilation in buildings dilutes indoor-generated air pollutants (including bioaerosols) and reduces resulting occupant exposures. Many countries and organizations have advisory guidelines or mandatory standards for minimum ventilation rates (VRs) to maintain indoor air quality (IAQ). Because directly measuring VRs is often difficult, many IAQ guidelines instead specify indoor concentration limits for carbon dioxide (CO 2 ), using CO 2 exhaled by building occupants as an indicator of VR. Although indoor CO 2 guidelines are common, the evidence basis for the various CO 2 limits has not been clear., Objective: To review current indoor CO 2 guidelines worldwide and the supportive evidence provided., Methods: We identified worldwide CO 2 -based guidelines for IAQ or ventilation, along with any supportive evidence provided. We excluded occupational guidelines for CO 2 levels ≥5000 ppm., Results: Among 43 guidelines identified, 35 set single CO 2 concentration limits and eight set multi-tiered limits; 16 mentioned no specific human effect to be controlled, 19 specified only odor dissatisfaction, five specified non-infectious health effects, and three specified airborne infectious disease transmission. The most common indoor CO 2 limit was 1000 ppm. Thirteen guidelines specified maximum CO 2 limits as extended time-weighted averages, none with evidence linking averaged limits to occupant effects. Of only 18 guidelines citing evidence to support limits set, we found this evidence persuasive for eight. Among these eight guidelines, seven set limits to control odor perception. One provided 17 scientifically-based CO 2 limits, for specific example space uses and occupancies, to control long-range COVID-19 transmission indoors., Impact: Many current indoor carbon dioxide (CO 2 ) guidelines for indoor air quality specified no adverse effects intended for control. Odor dissatisfaction was the effect mentioned most frequently, few mentioned health, and three mentioned control of infectious disease. Only one CO 2 guideline was developed from scientific models to control airborne transmission of COVID-19. Most guidelines provided no supportive evidence for specified limits; few provided persuasive evidence. No scientific basis is apparent for setting one CO 2 limit for IAQ across all buildings, setting a CO 2 limit for IAQ as an extended time-weighted average, or using any arbitrary one-time CO 2 measurement to verify a desired VR., (© 2024. The Author(s), under exclusive licence to Springer Nature America, Inc.)

Background: Unidirectional displacement flow (UDF) ventilation systems in operating rooms are characterized by a uniformity of velocity ≥80% and protect patients and operating room personnel against exposure to hazardous substances. However, the air below the surgical lights and in the surrounding zone is turbulent, which impairs the ventilation system's effect., Aim: We first used the recovery time (RT) as specified in International Organization for Standardization 14644 to determine the particle reduction capacity in the turbulent spaces of an operating room with a UDF system., Methods: The uniformity of velocity was analyzed by comfort-level probe grid measurements in the protected area below a hemispherical closed-shaped and a semi-open column-shaped surgical light (tilt angles: 0°/15°/30°) and in the surrounding zone of a research operating room. Thereafter, RTs were calculated., Results: At a supply air volume of 10,500 m 3 /h, the velocity, reported as average uniformity ± standard deviation, was uniform in the protected area without lights (95.8% ± 1.7%), but locally turbulent below the hemispherical closed-shaped (69.3% ± 14.6%), the semi-open column-shaped light (66.9% ± 10.9%), and in the surrounding zone (51.5% ± 17.6%). The RTs ranged between 1.1 and 1.7 min below the lights and 3.5 ± 0.28 min in the surrounding zone and depended exponentially on the volume flow rate., Conclusions: Compared to an RT of ≤20 min as required for operating rooms with mixed dilution flow, particles here were eliminated 12-18 times more quickly from below the surgical lights and 5.7 times from the surrounding zone. Thus, the effect of the lights was negligible and the UDF's retained its strong protective effect., Competing Interests: Declaration of Conflicting InterestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Data were collected to characterize whole-house mechanical ventilation (WHMV) and indoor air quality (IAQ) in 55 homes in the Marine climate of Oregon and the Cold-Dry climate of Colorado in the U.S. Sixteen homes were monitored for two weeks, with and without WHMV operating. Ventilation airflows; airtightness; time-resolved CO 2 , PM 2.5 and radon; and time-integrated NO 2 , NO X and formaldehyde were measured. Participants provided information about IAQ-impacting activities, perceptions and ventilation use. All homes had operational cooktop ventilation and bathroom exhaust. Thirty homes had equipment that could meet the ASHRAE 62.2–2010 standard with continuous or controlled runtime and 34 had some WHMV operating as found. Thirty-five of 46 participants with WHMV reported they did not know how to operate it, and only half of the systems were properly labeled. Two-week homes had lower formaldehyde, radon, CO 2 and NO (NO X -NO 2) when operated with WHMV, and had faster PM 2.5 decays following indoor emission events. Overall IAQ satisfaction was similar in Oregon and Colorado, but more Colorado participants (19% vs 3%) felt their IAQ could be improved and more reported dryness as a problem (58% vs. 14%). The collected data indicate that there are benefits of operating WHMV, even when continuous use may not be needed because outdoor pollutant concentrations are low and indoor sources do not present substantial challenges. • Whole-house mechanical ventilation (WHMV) and IAQ characterized in 55 homes; 16 with/out WHMV. • 31 of 42 had WHMV airflow that complied with ASHRAE 62.2–2010 • >50% of WMHV systems not labeled; few occupants knew how to operate them. • Formaldehyde, radon, CO 2 and NO lower in homes with WHMV running. • Faster PM 2.5 decay rates after indoor emission events in homes with WHMV running. [ABSTRACT FROM AUTHOR]

Introduction: Adherence to the design values and ventilation standards (VS) after installing and also maintaining continuous work of ventilation system with maximum performance throughout its life are amongst the reasons of ventilation systems monitoring. Therefore, the aim of this study was to evaluate performance of local exhaust ventilation system for control of dust by measuring the operating parameters and also to compare it with ventilation standards (VS) and design values. Material and Method: The present research is a descriptive and cross-sectional study, conducted in three sections of measuring, monitoring and evaluating the operating parameters on hoods, channels and fan of ventilation system based on the current status of the system, documentation (design), and recommended standards (VS). Static pressure, velocity pressure, surface area, and flow rate were measured based on the recommendations of various sources and ACGIH industrial ventilation manual, and the data were compared with the design and recommended values, using the SPSS software version 16. Result: The results of paired sample t-test between flow rate and velocities of design and current status, showed significant differences in various parts. Accordingly, the results revealed a reduction of more than 50% in the design duct velocity compared to the current duct velocity, while design duct velocity is 1.3 more than the standard duct velocity of current status, and current duct velocity is about 65% of standard duct velocity. Conclusion: The reduction and nonconformity of the results of measurements of operating parameters (after a minimum of two decades) with design and standard values are corroborant and sufficient reason for obstructions, abrasions, leaks, imbalance of system ducts and their inefficiency in some branches. Since there is no base line measurements for system (supposing that the system worked with maximum amounts of setup time), one of the reasons for these changes can be attributed to lack of schedule for regular and appropriate maintenance.

This research assesses benefits of adding to California Title-24 ventilation rate ( VR) standards a performance-based option, similar to the American Society of Heating, Refrigerating, and Air Conditioning Engineers ' Indoor Air Quality Procedure' ( IAQP) for retail spaces. Ventilation rates and concentrations of contaminants of concern ( Co C) were measured in 13 stores. Mass balance models were used to estimate ' IAQP-based' VRs that would maintain concentrations of all Co Cs below health- or odor-based reference concentration limits. An intervention study in a 'big box' store assessed how the current VR, the Title 24-prescribed VR, and the IAQP-based VR (0.24, 0.69, and 1.51 air changes per hour) influenced measured IAQ and perceived of IAQ. Neither current VRs nor Title 24-prescribed VRs would maintain all Co Cs below reference limits in 12 of 13 stores. In the big box store, the IAQP-based VR kept all Co Cs below limits. More than 80% of subjects reported acceptable air quality at all three VRs. In 11 of 13 buildings, saving energy through lower VRs while maintaining acceptable IAQ would require source reduction or gas-phase air cleaning for Co Cs. In only one of the 13 retail stores surveyed, application of the IAQP would have allowed reduced VRs without additional contaminant-reduction strategies. [ABSTRACT FROM AUTHOR]

A new design method is proposed to calculate outdoor air ventilation rates to control respiratory infection risk in indoor spaces. We propose to use this method in future ventilation standards to complement existing ventilation criteria based on the perceived air quality and pollutant removal. The proposed method makes it possible to calculate the required ventilation rate at a given probability of infection and quanta emission rate. Present work used quanta emission rates for SARS-CoV-2 and consequently the method can be applied for other respiratory viruses with available quanta data. The method was applied to case studies representing typical rooms in public buildings. To reduce the probability of infection, the total airflow rate per infectious person revealed to be the most important parameter to reduce the infection risk. Category I ventilation rate prescribed in the EN 16798-1 standard satisfied many but not all type of spaces examined. The required ventilation rates started from about 80 L/s per room. Large variations between the results for the selected case studies made it impossible to provide a simple rule for estimating the required ventilation rates. Consequently, we conclude that to design rooms with a low infection risk the newly developed ventilation design method must be used., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2021 The Authors.)

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that has created the current pandemic, has caused a worldwide worry. Different countries have since enforced varying levels of lockdowns and guidelines for their populations to follow in a serious effort to mitigate the spread. Up until recently, the majority of these regulations and policies were established on the assumption that the dominant routes of transmission of this virus are through droplets and fomite contact. However, there is now a substantial amount of research pointing towards the strong possibility that SARS-CoV-2 can spread through airborne means. The World Health Organization (WHO) and the Center for Disease Control and Prevention (CDC) have recently recognized this, which poses the question of whether our collective methods of lessening transmission risk and keeping people safe have been sufficient. This paper is a comprehensive review of the evidence on SARS-CoV-2 being an airborne disease, through different epidemiological, experimental, and animal-model based published research. Studies opposing this evidence have also been discussed. The majority of these studies are favoring the high plausibility of SARS-CoV-2 aerosol transmission, and therefore the many implications of aerosol transmission have been discussed in this paper to suggest effective mitigation and control strategies.

COVID-19 is around the world. We attempt to apply three-step method in ISO/IEC Guide 51: 2014 to COVID-19 infection control in the workplace. The results show that the COVID-19 infection control measures include the eradication of the virus, the destruction of infectivity, the detoxification and weakening and the elimination of opportunities for infection as "Inherently Safe Design Measures", the avoidance of contact as "Safeguarding and Complementary Protective Measures" and the reduction of contact and the avoidance of seriousness as "Information for Use". Among these specific measures, the New Normal, especially in the manufacturing industries, would be "telecommuting" and "unmanned workplaces", which are part of the elimination of opportunities for infection, and "changes in flow lines" and "changes in airflow", which are part of the avoidance of contact. Where "telecommuting" and "unmanned workplaces" are feasible, they should be implemented as much as possible, and where they are not, attempts should be made to minimize human-to-human contact by "changes in flow lines". In addition, in the area of "changes in airflow", there are high expectations for future research on how to establish a ventilation design for COVID-19, in which but also the source would be workers themselves, not only combustible gases and toxic gases.

Indoor carbon dioxide (CO 2) is a critical parameter in the design and control of ventilation, and in monitoring fresh air levels in buildings. Building occupants are primary sources for indoors CO 2 , and the rate at which CO 2 is generated depends on the occupants' physical activities. In the past, CO 2 generation rates have been indirectly calculated from metabolic rate data. There has been little systematic experimental determination of human CO 2 generation rates at different activity levels. This study experimentally determines human CO 2 generation rates for use in building design and control applications. CO 2 generation rates were obtained by a high accuracy indirect calorimetry system on 99 human subjects aged from 20 to 70, who were asked to perform 18 activities (including office, household, and walking activities) in a climatic chamber controlled at 26 °C. CO 2 generation rates increase significantly as activity levels increase. Age was found to have a small effect, while gender differences were significant. Women produced less CO 2 than men at the same activity levels, mainly attributable to their lower body masses. Regression models were developed based on activity levels and age for each gender to predict CO 2 generation rates. Significant discrepancies were found between measured CO 2 generation rates predicted by the models in ASHRAE 62.1–16 and ASTM D6245-18, especially at higher activity levels. These findings provide fundamental data for designers and researchers in ventilation and indoor air quality field, and future ventilation standard revisions. • Experimental study using human subjects with aged 20–70 years. • CO2 generation rates measured directly from light to moderate activity levels. • Age has a small effect while gender effect is significant. • Males generate more CO2 than females at the same activity levels. • Significant discrepancies between measured and standard values. [ABSTRACT FROM AUTHOR]

Grocery store workers are essential workers, but often have not been provided with appropriate protection during the current pandemic. This report describes efforts made by one union local to protect workers, including negotiated paid sick leave and specific safety practices. Union representatives from 319 stores completed 1612 in-store surveys to assess compliance between 23 April 2020 and 31 August 2020. Employers provided the union with lists of workers confirmed to have COVID-19 infection through 31 December 2020. Worker infection rates were calculated using store employees represented by the union as the denominator and compared to cumulative county infection rates; outcome was dichotomized as rates higher or lower than background rates. Restrictions on reusable bags and management enforcement of customer mask usage were most strongly associated with COVID-19 rates lower than rates in the surrounding county. Stores that responded positively to worker complaints also had better outcomes. The union is currently engaging to promote improved ventilation and vaccination uptake.

Background: The novel coronavirus disease 2019 (COVID-19) undermines the benefits of cancer screening. To date, no study has identified specific infection control methods. We aimed to provide practical methods for COVID-19 risk reduction during breast cancer screening mammography (MMG) by examining an overview of potential contamination routes of aerosols and possible risks for patients and health care providers., Methods: Computational fluid dynamics (CFD) simulations were conducted for airflow and aerosol dispersion in a 3D virtual model of a mobile MMG laboratory room. This model was constructed based on the actual mobile screening MMG bus 'Cosmos' in the Chiba Foundation for Health Promotion & Disease Prevention. Examiner and patient geometries were obtained by scanning an actual human using a 3D Scanner. Contamination of the room was evaluated by counting the numbers of suspended and deposited aerosols., Results: We applied the CFD simulation model to the exhalation of small or large aerosols from a patient and examiner in the MMG laboratory. Only 14.5% and 54.5% of large and small aerosols, respectively, were discharged out of the room with two doors open. In contrast, the proportion of large and small aerosols discharged out of the room increased to 96.6% and 97.9%, respectively, with the addition of forced gentle wind by the blower fan. This simulation was verified by a mist aerosol experiment conducted in the mobile MMG laboratory., Conclusion: Adding forced ventilation to a MMG laboratory with two doors open may enable risk reduction dramatically. This could be applied to other clinical situations.

To meet the educational, physical, social, and emotional needs of children, many U.S. schools opened for in-person learning during fall 2020 by implementing strategies to prevent transmission of SARS-CoV-2, the virus that causes COVID-19 (1,2). To date, there have been no U.S. studies comparing COVID-19 incidence in schools that varied in implementing recommended prevention strategies, including mask requirements and ventilation improvements* (2). Using data from Georgia kindergarten through grade 5 (K-5) schools that opened for in-person learning during fall 2020, CDC and the Georgia Department of Public Health (GDPH) assessed the impact of school-level prevention strategies on incidence of COVID-19 among students and staff members before the availability of COVID-19 vaccines. † Among 169 K-5 schools that participated in a survey on prevention strategies and reported COVID-19 cases during November 16-December 11, 2020, COVID-19 incidence was 3.08 cases among students and staff members per 500 enrolled students. § Adjusting for county-level incidence, COVID-19 incidence was 37% lower in schools that required teachers and staff members to use masks, and 39% lower in schools that improved ventilation, compared with schools that did not use these prevention strategies. Ventilation strategies associated with lower school incidence included methods to dilute airborne particles alone by opening windows, opening doors, or using fans (35% lower incidence), or in combination with methods to filter airborne particles with high-efficiency particulate absorbing (HEPA) filtration with or without purification with ultraviolet germicidal irradiation (UVGI) (48% lower incidence). Multiple strategies should be implemented to prevent transmission of SARS-CoV-2 in schools (2); mask requirements for teachers and staff members and improved ventilation are important strategies that elementary schools could implement as part of a multicomponent approach to provide safer, in-person learning environments. Universal and correct mask use is still recommended by CDC for adults and children in schools regardless of vaccination status (2)., Competing Interests: All authors have completed and submitted the International Committee of Medical Journal Editors form for disclosure of potential conflicts of interest. No potential conflicts of interest were disclosed.

Objectives, Purposes, or Aim: To identify design strategies utilized in airborne infection isolation and biocontainment patient rooms that improve infection control potential in an alternative care environment., Background: As SARS-CoV-2 spreads and health care facilities near or exceed capacity, facilities may implement alternative care sites (ACSs). With COVID-19 surges predicted, developing additional capacity in alternative facilities, including hotels and convention centers, into patient care environments requires early careful consideration of the existing space constraints, infrastructure, and modifications needed for patient care and infection control. Design-based strategies utilizing engineering solutions have the greatest impact, followed by medical and operational strategies., Methods: This article evaluates infection control and environmental strategies in inpatient units and proposes system modifications to ACS surge facilities to reduce infection risk and improve care environments., Results: Although adequate for an acute infectious disease outbreak, existing capacity in U.S. biocontainment units and airborne infection isolation rooms is not sufficient for widespread infection control and isolation during a pandemic. To improve patients' outcomes and decrease infection transmission risk in the alternative care facility, hospital planners, administrators, and clinicians can take cues from evidence-based strategies implemented in biocontainment units and standard inpatient rooms., Conclusions: Innovative technologies, including optimized air-handling systems with ultraviolet and particle filters, can be an essential part of an infection control strategy. For flexible surge capacity in future ACS and hospital projects, interdisciplinary design and management teams should apply strategies optimizing the treatment of both infectious patients and minimizing the risk to health care workers.

Several of the key organizational issues that we have had to face with the emergence of COVID-19 crisis are related to human factors/ergonomics (HFE) and the safety culture. During the crisis the main activities of the healthcare services have been profoundly affected. Patient safety and risk management units have also experienced the need to adapt rapidly. What can we do as HFE experts, now that the scenario has completely changed? We contend that: (a) we can favour and support the heuristics that are applied to manage the load of psycho-cognitive stress. (b) We can observe, collect strategies and develop analytic schemes, thereby creating a memory of the organization for improvement in the future. (c) And we can support in educating and engaging the public. This crisis has forced the community of healthcare experts to broaden their reflections: for the future to come, our communities of experts in the field of risk management HF/E, quality and safety of care and public health should play together an important role from the very beginning, from the time of peace., (© The Author(s) 2020. Published by Oxford University Press in association with the International Society for Quality in Health Care. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Adipose-derived stromal cells (ADSCs) showed excellent capacity in regeneration and tissue protection. Low tidal volume ventilation (LVT) strategy demonstrates a therapeutic benefit on the treatment of acute lung injury/acute respiratory distress syndrome (ALI/ARDS). This study, therefore, aimed to undertaken determine whether the combined LVT and ADSCs treatment exerts additional protection against lipopolysaccharide (LPS)-induced ALI in rats. The animals were randomized into seven groups: Group I (control), Group II (instillation of LPS at 10 mg/kg intratracheally), Group III (LPS+LVT 6 ml/kg), Group IV (LPS+intravenous autologous 5 × 10 6 ADSCs which were pretreated with a scrambled small interfering RNA [siRNA] of keratinocyte growth factor [KGF] negative control), Group V (LPS+ADSCs which were pretreated with a scrambled siRNA of KGF, Group VI (LPS+LVT and ADSCs as in the Group IV), and Group VII (LPS+LVT and ADSCs as in the Group V). We found that levels of tumor necrosis factor-α, transforming growth factor-β1, and interleukin (IL)-1β and IL-6, the proinflammatory cytokines, were remarkably increased in LPS rats. Moreover, the expressions of ENaC, activity of Na, K-ATPase, and alveolar fluid clearance (AFC) were obviously reduced by LPS-induced ALI. The rats treated by ADSCs showed improved effects in all these changes of ALI and further enhanced by ADSCs combined with LVT treatment. Importantly, the treatment of ADSCs with siRNA-mediated knockdown of KGF partially eliminated the therapeutic effects. In conclusion, combined treatment with ADSCs and LVT not only is superior to either ADSCs or LVT therapy alone in the prevention of ALI. Evidence of the beneficial effect may be partly due to improving AFC by paracrine or systemic production of KGF and anti-inflammatory properties., (© 2020 Wiley Periodicals LLC.)

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes 2019 novel coronavirus disease (COVID-19), has rapidly developed into a global pandemic and public health emergency. The transmission and virulence of this new pathogen have raised concern for how best to protect healthcare professionals while effectively providing care to the infected patient requiring surgery. Although negative pressure rooms are ideal for aerosol-generating procedures, such as intubation and extubation, most operating theatres are generally maintained at a positive pressure when compared with the surrounding areas. This article compares negative and positive pressure rooms and the advantages of a negative pressure environment in optimising clinical care and minimising the exposure of patients and health care professionals to SARS-CoV-2.

Objectives: Beauty is a Lebanese stereotype, as Lebanese women often feel urged to decorate themselves. Recent studies have raised concerns about nail salon technicians' (NSTs) health and safety issues. The aim of our study was to evaluate the occupational symptoms reported by NSTs, to assess their knowledge and document their awareness regarding hazardous chemicals found in nail cosmetics., Methods: NSTs completed a researcher-administered questionnaire. Data were gathered on sociodemographic characteristics, perceived knowledge, and safety issues. Work-related symptoms reported by NSTs were evaluated, and their responses were compared to those of the office employees., Results: A total of 120 NSTs and 120 office employees were interviewed. Compared to the control group, NSTs reported a higher prevalence of work-related respiratory, dermal, and irritative symptoms, all significantly associated with smoking and a poor ventilation system. In addition, musculoskeletal complaints were common among NSTs and significantly linked to a poor ventilation system, an increased number of customers per day, and a longer service duration. Furthermore, a longer career duration was significantly associated with an increased prevalence of irritative symptoms. When a binary logistic regression was carried out, it demonstrated a 25 times higher prevalence of work-related symptoms among NSTs compared to the office employees. Interestingly, 84% of the respondents had an inaccurate knowledge of nail cosmetics' risks with their educational level acting as key factor., Conclusions: Based on these findings, it is warranted to perform a clinical assessment, implement a stringent regulatory framework, and improve knowledge toward nail cosmetics' risk.

Bioaerosols are known to be an important transmission pathway for SARS-CoV-2. We report a framework for estimating the risk of transmitting SARS-CoV-2 via aerosols in laboratory and office settings, based on an exponential dose-response model and analysis of air flow and purification in typical heating, ventilation, and air conditioning (HVAC) systems. High-circulation HVAC systems with high-efficiency particulate air (HEPA) filtration dramatically reduce exposure to the virus in indoor settings, and surgical masks or N95 respirators further reduce exposure. As an example of our risk assessment model, we consider the precautions needed for a typical experimental physical science group to maintain a low risk of transmission over six months of operation. We recommend that, for environments where fewer than five individuals significantly overlap, work spaces should remain vacant for between one (high-circulation HVAC with HEPA filtration) to six (low-circulation HVAC with no filtration) air exchange times before a new worker enters in order to maintain no more than 1% chance of infection over six months of operation in the workplace. Our model is readily applied to similar settings that are not explicitly given here. We also provide a framework for evaluating infection mitigation through ventilation in multiple occupancy spaces.

Coronavirus disease 2019, otherwise referred to as COVID-19, started in China and quickly became a worldwide pandemic. Beginning in March 2020, nonessential businesses in the United States were closed, and many communities were under shelter-in-place orders. As of May 2020, some business sectors started reopening, even amidst concerns of worker health as the pandemic continued. In addition to physical distancing, cleaning and disinfection routines, and using face coverings, building ventilation can also be an important risk mitigation measure for controlling exposure to SARS-CoV-2 indoors. A number of studies to date, however, have focused on ventilation in medical facilities (e.g. hospitals) as the risk of transmission of SARS-CoV-2 is higher there (because of the close proximity of workers to patients who have the disease and their treatment procedures). Few studies have focused on ventilation use in nonmedical settings (e.g. office buildings and school classrooms), despite the large population of workers and community members in these facilities. In this article, we review the role that building ventilation can play in minimizing the risk of SARS-CoV-2 transmission in nonmedical environments and some recommended protocols to follow for its proper use, including cleaning and maintaining mechanical ventilation systems for businesses, schools, and homes.

Introduction: Recent respiratory infectious disease (RID) outbreaks of influenza and the novel coronavirus have resulted in global pandemics. RIDs can trigger nosocomial infections if not adequately prevented., Objective: The objective of this study was to rate the adequacy of healthcare workers (HCWs) and hospital settings on RID prevention using unannounced standardized patients (USP) in clinical settings of hospital gateways., Methods: Trained USPs visited 5 clinical settings: information desks, registration desks, two outpatient departments and the emergency departments in 10 hospitals across 3 cities of Inner Mongolia, China. USPs observed the hospital air ventilation and distance from the nearest hand-washing facilities to each clinical setting, then mimicked symptoms of either tuberculosis or influenza before observing the HCW's behavior. A total of 480 clinical-setting assessments were made by 19 USPs., Results: The overall adequacy of triage services was 86.7% and for prevention of the spread of airborne droplets was 83.5%. Almost all hospitals offered adequate air ventilation. Compared to the information desk, adequacy of triage and preventing the spread of airborne droplets by physicians in the three clinical departments was less likely to be adequate. Triage services for USPs simulating symptoms of influenza were 2.6 times more likely to be adequate than for those simulating symptoms of tuberculosis but there was no significant difference in the prevention of the spread of airborne droplets., Conclusions: There is a need to improve respiratory infectious disease procedures in our study hospitals, especially in outpatient and emergency departments.

Aims: To assess the impact of two different respiratory rates in hemodynamic, perfusion and ventilation parameters in a pediatric animal model of cardiac arrest (CA)., Methods: An experimental randomized controlled trial was carried out in 50 piglets under asphyxial CA. After ROSC, they were randomized into two groups: 20 and 30 respirations per minute (rpm). Hemodynamic, perfusion and ventilation parameters were measured 10 minutes after asphyxia, just before ROSC and at 5, 15, 30 and 60 minutes after ROSC. Independent medians test, Kruskal-Wallis test and χ2 test, were used to compare continuous and categorical variables, respectively. Spearman's Rho was used to assess correlation between continuous variables. A p-value <0.05 was considered significant., Results: Arterial partial pressure of carbon dioxide (PaCO2) was significantly lower in the 30 rpm group after 15 minutes (41 vs. 54.5 mmHg, p <0.01), 30 minutes (39.5 vs. 51 mmHg, p < 0.01) and 60 minutes (36.5 vs. 48 mmHg, p = 0.02) of ROSC. The percentage of normoventilated subjects (PaCO2 30-50 mmHg) was significantly higher in the 30 rpm group throughout the experiment. pH normalization occurred faster in the 30 rpm group with significant differences at 60 minutes (7.40 vs. 7.34, p = 0.02). Lactic acid levels were high immediately after ROSC in both groups, but were significantly lower in the 20 rpm group at 30 (3.7 vs. 4.7 p = 0.04) and 60 minutes (2.6 vs. 3.6 p = 0.03)., Conclusions: This animal model of asphyxial CA shows that a respiratory rate of 30 rpm is more effective to reach normoventilation than 20 rpm in piglets after ROSC. This ventilation strategy seems to be safe, as it does not cause hyperventilation and does not affect hemodynamics or cerebral tissue perfusion., Competing Interests: The authors have declared that no competing interests exist.

Coronavirus disease 2019 (COVID-19) is a global health threat. A hospital in Zhuhai adopted several measures in Fever Clinic Management (FCM) to respond to the outbreak of COVID-19. FCM has been proved to be effective in preventing nosocomial cross infection. Faced with the emergency, the hospital undertook creative operational steps in relation to the control and spread of COVID-19, with special focuses on physical and administrative layout of buildings, staff training and preventative procedures. The first operational step was to set up triaging stations at all entrances and then complete a standard and qualified fever clinic, which was isolated from the other buildings within our hospital complex. Secondly, the hospital established its human resource reservation for emergency response and the allocation of human resources to ensure strict and standardised training methods through the hospital for all medical staff and ancillary employees. Thirdly, the hospital divided the fever clinic into partitioned areas and adapted a three-level triaging system. The experiences shared in this paper would be of practical help for the facilities that are encountering or will encounter the challenges of COVID-19, i.e. to prevent nosocomial cross infection among patients and physicians.

We advocate the widespread use of UV-C light as a short-term, easily deployable, and affordable way to limit virus spread in the current SARS-CoV-2 pandemic. Radical social distancing with the associated shutdown of schools, restaurants, sport clubs, workplaces, and traveling has been shown to be effective in reducing virus spread, but its economic and social costs are unsustainable in the medium term. Simple measures like frequent handwashing, facial masks, and other physical barriers are being commonly adopted to prevent virus transmission. However, their efficacy may be limited, particularly in shared indoor spaces, where, in addition to airborne transmission, elements with small surface areas such as elevator buttons, door handles, and handrails are frequently used and can also mediate transmission. We argue that additional measures are necessary to reduce virus transmission when people resume attending schools and jobs that require proximity or some degree of physical contact. Among the available alternatives, UV-C light satisfies the requirements of rapid, widespread, and economically viable deployment. Its implementation is only limited by current production capacities, an increase of which requires swift intervention by industry and authorities.

Background: The air in the operating room is considered a risk factor for surgical site infection (SSI) due to airborne bacteria shed from the surgical staff or from patients themselves., Aim: To assess the influence of validated operating room (OR) ventilation data on the risk of revision surgery due to deep infection after primary total hip arthroplasty (THA) reported to the Norwegian Arthroplasty Register (NAR)., Methods: Forty orthopaedic units reporting THAs to the NAR during the period 2005-2015 were included. The true type of OR ventilation in all hospitals at the time of primary THA was confirmed in a previous study. Unidirectional airflow (UDF) systems were subdivided into: small, low-volume, unidirectional vertical flow (lvUDVF) systems; large, high-volume, unidirectional vertical flow (hvUDVF) systems; and unidirectional horizontal flow (UDHF) systems. These three ventilation groups were compared with conventional, turbulent, mixing ventilation (CV). The association between the end-point, time to revision due to infection, and OR ventilation was estimated by calculating relative risks (RRs) in a multivariate Cox regression model, with adjustments for several patient- and surgery-related covariates., Findings: A total of 51,292 primary THAs were eligible for assessment. Of these, 575 had been revised due to infection. A similar risk of revision due to infection after THA performed was found in ORs with lvUDVF and UDHF compared to CV. THAs performed in ORs with hvUDVF had lower risk of revision due to infection compared to CV (RR = 0.8; 95% CI: 0.6-0.9; P = 0.01)., Conclusion: THAs performed in ORs with hvUDVF systems had lower risk of revision due to infection compared to THAs performed in ORs with CV systems. The perception that all UDF systems are similar and possibly harmful seems erroneous., (Copyright © 2020 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Tracheostomy post-tracheostomy care are regarded as at high risk for contamination of health care professionals with the new coronavirus (SARS-CoV-2). Considering the rapid spread of the infection, all patients in France must be considered as potentially infected by the virus. Nevertheless, patients without clinical or radiological (CT scan) markers of COVID-19, and with negative nasopharyngeal sample within 24h of surgery, are at low risk of being infected. Instructions for personal protection include specific wound dressings and decontamination of all material used. The operating room should be ventilated after each tracheostomy and the pressure of the room should be neutral or negative. Percutaneous tracheostomy is to be preferred over surgical cervicotomy in order to reduce aerosolization and to avoid moving patients from the intensive care unit to the operating room. Ventilation must be optimized during the procedure, to limit patient oxygen desaturation. Drug assisted neuromuscular blockage is advised to reduce coughing during tracheostomy tube insertion. An experienced team is mandatory to secure and accelerate the procedure as well as to reduce risk of contamination., (Copyright © 2020. Published by Elsevier Masson SAS.)

While residential energy and ventilation standards aim to improve the energy performance and indoor air quality (IAQ) of homes, their combined impact across diverse residential activities and housing environments has not been well-established. This study demonstrates the insights that a recently-developed, freely-available coupled IAQ-energy modeling platform can provide regarding the energy and IAQ trade-offs of weatherization (i.e., sealing and insulation) and ventilation retrofits in multifamily housing across varied indoor occupant activity and mechanical ventilation scenarios in Boston, MA. Overall, it was found that combined weatherization and improved ventilation recommended by design standards could lead to both energy savings and IAQ-related benefits; however, ventilation standards may not be sufficient to protect against IAQ disbenefits for residents exposed to strong indoor sources (e.g., heavy cooking or smoking) and could lead to net increases in energy costs (e.g., due to the addition of continuous outdoor air ventilation). The modeling platform employed in this study is flexible and can be applied to a wide range of building typologies, retrofits, climates, and indoor occupant activities; therefore, it stands as a valuable tool for identifying cost-effective interventions that meet both energy efficiency and ventilation standards and improve IAQ across diverse housing populations.

Aim: Current resuscitation guidelines recommend waveform capnography as an indirect indicator of perfusion during cardiopulmonary resuscitation (CPR). Chest compressions (CCs) and ventilations during CPR have opposing effects on the exhaled carbon dioxide (CO2) concentration, which need to be better characterized. The purpose of this study was to model the impact of ventilations in the exhaled CO2 measured from capnograms collected during out-of-hospital cardiac arrest (OHCA) resuscitation., Methods: We retrospectively analyzed OHCA monitor-defibrillator files with concurrent capnogram, compression depth, transthoracic impedance and ECG signals. Segments with CC pauses, two or more ventilations, and with no pulse-generating rhythm were selected. Thus, only ventilations should have caused the decrease in CO2 concentration. The variation in the exhaled CO2 concentration with each ventilation was modeled with an exponential decay function using non-linear-least-squares curve fitting., Results: Out of the original 1002 OHCA dataset (one per patient), 377 episodes had the required signals, and 196 segments from 96 patients met the inclusion criteria. Airway type was endotracheal tube in 64.8% of the segments, supraglottic King LT-D™ in 30.1%, and unknown in 5.1%. Median (IQR) decay factor of the exhaled CO2 concentration was 10.0% (7.8 - 12.9) with R2 = 0.98(0.95 - 0.99). Differences in decay factor with airway type were not statistically significant (p = 0.17). From these results, we propose a model for estimating the contribution of CCs to the end-tidal CO2 level between consecutive ventilations and for estimating the end-tidal CO2 variation as a function of ventilation rate., Conclusion: We have modeled the decrease in exhaled CO2 concentration with ventilations during chest compression pauses in CPR. This finding allowed us to hypothesize a mathematical model for explaining the effect of chest compressions on ETCO2 compensating for the influence of ventilation rate during CPR. However, further work is required to confirm the validity of this model during ongoing chest compressions., Competing Interests: Author Digna María González-Otero is employed by Bexen Cardio, a Spanish medical device manufacturer. Bexen Cardio had no additional role in study funding, or study design, data collection and analysis, decision to publish, or preparation of the manuscript. This does not alter our adherence to PLOS ONE policies on sharing data and materials.

Background Context: Exposure to surgical smoke remains a potential occupational health concern to spine operating room personnel. Using a smoke evacuator (local exhaust ventilation) is currently regarded as a primary means of protection, yet few studies have evaluated its utility in actual surgeries., Objective: To examine the utility of two common types of local smoke evacuators, a para incisional evacuator and a smoke evacuation pencil, in reducing surgical smoke exposure in spine surgery., Study Design: A prospective self-controlled study., Patient Sample: After the pre-estimation of sample size, 51 consecutive spine surgeries (25 and 26 patients using the para incisional smoke evacuator and the smoke evacuation pencil, respectively) were enrolled between February 2018 and March 2019., Outcome Measures: Two outcome measures were used to evaluate the level of surgical smoke exposure, which was defined as the concentration of ultrafine smoke particles in the air (number of particles per cm 3 , ppc) around the operating table: (a) the average smoke level was the arithmetic mean of all measurements recorded during the surgery; and (b) the peak smoke level was the highest measurement recorded., Methods: Consecutive surgeries that involved bilateral symmetrical surgical exposure of the spine via a posterior midline incision were evaluated. Cauterized smoke was evacuated by two smoke evacuators: a "para incisional evacuator," which used a flat broad suction pad positioned immediately adjacent to the incision (25 patients), and a "surgical smoke evacuation pencil" which is an incorporated part of the electrocautery (26 patients). The level of smoke exposure was measured separately when surgically exposing the two sides of the spine: starting with one side (determined randomly) with the smoke evacuator being turned on and, then, the other side with the smoke evacuator off. The results were compared between the two sides., Results: The para incisional smoke evacuator significantly reduced the average smoke level by an average of 59.7% (287 [interquartile range {IQR}: 126, 526] vs. 1,177 [IQR: 395, 2,702], p<.001). The surgical smoke evacuation pencil also reduced the average smoke level by an average of 44.1% (917 [IQR: 448, 1936] vs. 1,605 [IQR: 775, 4,280], p<.001). Both evacuators significantly reduced peak smoke levels as well., Conclusions: This study provides evidence supporting the utility of local smoke evacuation in reducing surgical smoke exposure in spine surgery. Such technology may help to improve the occupational health protection for spine operating room workers., (Copyright © 2019 The Author(s). Published by Elsevier Inc. All rights reserved.)

Surgical staff behavior in operating theatres is one of the factors associated with indoor air quality and surgical site infection risk. The aim of this study was to apply an approach including microbiological, particle, and microclimate parameters during two simulated surgical hip arthroplasties to evaluate the influence of staff behavior on indoor air quality. During the first hip arthroplasty, the surgical team behaved correctly, but in the second operation, behavioral recommendations were not respected. Microbiological contamination was evaluated by active and passive methods. The air velocity, humidity, temperature, and CO 2 concentration were also monitored. The highest levels of microbial and particle contamination, as well as the highest variation in the microclimate parameter, were recorded during the surgical operation where the surgical team behaved "incorrectly". Turbulent air flow ventilation systems appeared more efficient than in the past and very low air microbial contamination was reached when behavior was correct. Therefore, adherence to behavioral recommendations in operating theatres is essential to not undermine the effectiveness of the heating, ventilation, and air conditioning systems and employed resources.

Schools provide a crucial platform for health promotion as the school years are a vital stage in one's life, where lifelong general and oral health-related behaviours are developed and established. The components of Health Promoting Schools (HPSs) suggested by World Health Organization provide guidance for facilitating health promotion within this setting. This study aimed to assess the adherence to the components of HPSs amongst schools in Bengaluru, India utilizing a comprehensive tool developed for the purpose. A cross-sectional survey was conducted among randomly selected 61 schools. Data were collected through structured interviews with the head of the schools, direct observation of school premises and verification of records. The significant findings of the study were that 80.3% of the schools had proper ventilation and separate washrooms for boys and girls, 83.6 and 88.5% of the schools had natural light and adequate water supply correspondingly. Only 39.3% of the schools had washrooms that were cleaned daily, and 55.7% of the schools were in proximity to business that sold tobacco products. Oral health education was not integrated into the curriculum in 39.3% of the schools, and 29.5% of the schools had no playgrounds. The study tool appeared to be sensitive in identifying the finer components of HPSs, indicating the lack of strict adherence to the components of HPSs in Bengaluru. This information can be utilized to design appropriate interventions at micro, meso and macro level to strengthen the capacity of schools for the attainment of health promotion., (© The Author(s) 2018. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

In 2011, following years of outreach and training, Boston, Massachusetts, enacted regulations to improve health and safety in nail salons. These were amended in 2013 to require mechanical ventilation, including dedicated exhaust for each manicure and pedicure station. As of June 2019, 185 of 190 salons have satisfied the regulatory requirements. Regulations can help ensure that environmental health benefits are widespread and that small businesses' investment in occupational health does not result in a competitive disadvantage.