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Objective: This study aimed to document and empirically evaluate the physical environment strategies used by emergency departments (EDs) to address the challenges posed by the COVID-19 pandemic; and to develop recommendations for managing future crises. Background: Emergency departments made significant environmental modifications in responding to the COVID-19 pandemic but these modifications and the decision-making processes were seldomly studied. Methods: In this in-depth qualitative case study, a multidisciplinary research team conducted semistructured interviews with 11 professionals of various roles in environmental responses to the pandemic at a large urban ED in the U.S. Qualitative content analysis generated codes and code categories from the data as well as a conceptual framework. Design documents and photographic documentation were used to cross-check the interview data. Results: The ED faced challenges in making rapid changes with limited information and resources. Physical barriers separating patients, air filtration, airflow control, and alternative care spaces were key physical environmental strategies implemented. Among them, the physical separation of patients was perceived to be most effective, followed by air quality control measures. Interviewees recommended flexibility in building design (self-contained zones, negative pressure and air filtration in all patient rooms, pandemic mode of air ventilation system), and an all-inclusive bottom-up decision-making process. Concerns included ventilation, security, communication strategies, and workplace ergonomics. Conclusion: The physical environment constitutes an important part of ED pandemic response and the proactive preparation for future crises. Hospitals should consider the ED environment's role in pandemic response, including ventilation capability, security visibility, and functionality for staff. [ABSTRACT FROM AUTHOR]

Purpose: Ventilatory constraints are common during exercise in children, but the effects of obesity and sex are unclear. The purpose of this study was to investigate the effects of obesity and sex on ventilatory constraints (i.e., expiratory flow limitation (EFL) and dynamic hyperinflation) during a maximal exercise test in children. Methods: Thirty-four 8- to 12-yr-old children without obesity (18 females) and 54 with obesity (23 females) completed pulmonary function testing and maximal cardiopulmonary exercise tests. EFL was calculated as the overlap between tidal flow–volume loops during exercise and maximal expiratory flow–volume loops. Dynamic hyperinflation was calculated as the change in inspiratory capacity from rest to exercise. Results: Maximal minute ventilation was not different between children with and without obesity. Average end-inspiratory lung volumes (EILV) and end-expiratory lung volumes (EELV) were significantly lower during exercise in children with obesity (EILV: 68.8% ± 0.7% TLC; EELV: 41.2% ± 0.5% TLC) compared with children without obesity (EILV: 73.7% ± 0.8% TLC; EELV: 44.8% ± 0.6% TLC; P < 0.001). Throughout exercise, children with obesity experienced more EFL and dynamic hyperinflation compared with those without obesity (P < 0.001). Also, males experienced more EFL and dynamic hyperinflation throughout exercise compared with females (P < 0.001). At maximal exercise, the prevalence of EFL was similar in males with and without obesity; however, the prevalence of EFL in females was significantly different, with 57% of females with obesity experiencing EFL compared with 17% of females without obesity (P < 0.05). At maximal exercise, 44% of children with obesity experienced dynamic hyperinflation compared with 12% of children without obesity (P = 0.002). Conclusions: Obesity in children increases the risk of developing mechanical ventilatory constraints such as dynamic hyperinflation and EFL. Sex differences were apparent with males experiencing more ventilatory constraints compared with females. [ABSTRACT FROM AUTHOR]

The article stresses the need to recommit to ventilation not as a technical standard for minimally acceptable conditions but as a cornerstone of public health. Topics discussed include the role of ventilation in medical settings to combat infections, the standard for ventilation released by the American Society of Heating and Ventilation Engineers (ASHRAE) in 1973, and the turning point in the history of ventilation in the year 2020.

Objective Both high altitude and trisomy 21 (T21) status can negatively impact respiratory outcomes. The objective of this study was to examine the association between altitude and perinatal respiratory support in neonates with T21 compared with those without T21. Study Design This retrospective cohort study used the United States all-county natality files that included live, singleton, in-hospital births from 2015 to 2019. Descriptive statistics for neonates with and without the primary outcome of sustained assisted ventilation (>6 hours) were compared using t -tests and Chi-squared analyses. Multivariable logistic regression was used to determine the association between respiratory support and the presence of T21, and included an interaction term to determine whether the association between respiratory support and the presence of T21 was modified by elevation at delivery. Results A total of 17,939,006 neonates, 4,059 (0.02%) with T21 and 17,934,947 (99.98%) without, were included in the study. The odds of requiring sustained respiratory support following delivery were 5.95 (95% confidence interval [CI]: 5.31, 6.66), 4.06 (95% CI: 2.39, 6.89), 2.36 (95% CI: 1.64, 3.40), and 5.04 (95% CI: 1.54, 16.54) times as high for neonates with T21 than without T21 when born at low, medium, high, and very high elevations, respectively. The odds of requiring immediate ventilation support following delivery were 5.01 (95% CI: 4.59, 5.46), 5.90 (95% CI: 4.16, 8.36), 2.86 (95% CI: 2.15, 3.80), and 12.08 (95% CI: 6.78, 21.51) times as high for neonates with T21 than without T21 when born at low, medium, high, and very high elevation, respectively. Conclusion Neonates with T21 have increased odds of requiring respiratory support following delivery when compared with neonates without T21 at all categories of altitude. However, the odds ratios did not increase monotonically with altitude which indicates additional research is critical in understanding the effects of altitude on neonates with T21. Key Points Neonates with T21 have an increased need for perinatal respiratory support at all altitudes. The odds of needing perinatal respiratory support did not increase monotonically with elevation. Additional research is critical to understanding the effects of altitude on neonates with T21. [ABSTRACT FROM AUTHOR]

Improving indoor air quality is one potential strategy to reduce the transmission of SARS-CoV-2 in any setting, including nursing homes, where staff and residents have been disproportionately and negatively affected by the COVID-19 pandemic. Single group interrupted time series. A total of 81 nursing homes in a multifacility corporation in Florida, Georgia, North Carolina, and South Carolina that installed ultraviolet air purification in their existing heating, ventilation, and air conditioning systems between July 27, 2020,k and September 10, 2020. We linked data on the date ultraviolet air purification systems were installed with the Nursing Home COVID-19 Public Health File (weekly data reported by nursing homes on the number of residents with COVID-19 and COVID-19 deaths), public data on data on nursing home characteristics, county-level COVID-19 cases/deaths, and outside air temperature. We used an interrupted time series design and ordinary least squares regression to compare trends in weekly COVID-19 cases and deaths before and after installation of ultraviolet air purification systems. We controlled for county-level COVID-19 cases, death, and heat index. Compared with pre-installation, weekly COVID-19 cases per 1000 residents (−1.69; 95% CI, −4.32 to 0.95) and the weekly probability of reporting any COVID-19 case (−0.02; 95% CI, −0.04 to 0.00) declined in the post-installation period. We did not find any difference pre- and post-installation in COVID-19–related mortality (0.00; 95% CI, −0.01 to 0.02). Our findings from this small number of nursing homes in the southern United States demonstrate the potential benefits of air purification in nursing homes on COVID-19 outcomes. Intervening on air quality may have a wide impact without placing significant burden on individuals to modify their behavior. We recommend a stronger, experimental design to estimate the causal effect of installing air purification devices on improving COVID-19 outcomes in nursing homes. [ABSTRACT FROM AUTHOR]

BACKGROUND: Pediatric patients with ARDS will on occasion need venovenous extracorporeal membrane oxygenation (VV-ECMO) for organ support. As these patients recover, they may benefit from lung recruitment maneuvers including flexible bronchoscopy (FB). The objective of this study was to assess the clinical course of patients who underwent FB while on VV-ECMO for ARDS. METHODS: This was a secondary analysis of a retrospective multi-center cohort at 10 United States pediatric academic quaternary care centers. Data were collected on 204 subjects age 14 d-18 y on VV-ECMO. RESULTS: 271 FBs were performed on 129 (63%) subjects. Pre-FB tidal volume was 1.8 mL/kg compared to 2.22 mL/kg following FB (P = .007). Dynamic compliance also improved from pre-FB to post-FB (2.23 vs 3.04 mL/cm H2O, P = .005). There was a low incidence of complications following FB (3.1%). Subjects in the FB group had fewer ECMO-free days (EFDs) (17.9 vs 22.1 d, P < .001), fewer ventilator-free days (VFDs) (40.0 vs 46.5 d, P = .001), and longer ICU length of stay (LOS) (18 vs 32 d, P < .001). Subjects in the early versus late FB group had more EFDs (19.4 vs 15.2 d, P = .003), more VFDs (43.0 vs 34.0 d, P = .004), and shorter ICU LOS (27.5 vs 35.5 d, P = .045). Mortality in the subjects who had at least one FB was 27.1% compared to 40% in the subjects who did not have a FB while on VV-ECMO (P = .057). CONCLUSIONS: FB can be performed on patients while anticoagulated on VV-ECMO with a low incidence of complications. FB may be beneficial especially when performed early in the course of VV-ECMO. [ABSTRACT FROM AUTHOR]

Fresh air ventilation has been identified as a widely accepted engineering control effective at diluting air contaminants in enclosed environments. The goal of this study was to evaluate the effects of selected ventilation measures on air change rates in school buses. Air changes per hour (ACH) of outside air were measured using a well-established carbon dioxide (CO2) tracer gas decay method. Ventilation was assessed while stationary and while traversing standardized route during late autumn/winter months in Colorado. Seven CO2 sensors located at the driver's seat and at passenger seats in the front, middle, and rear of the bus yielded similar and consistent measurements. Buses exhibited little air exchange in the absence of ventilation (ACH = 0.13 when stationary; ACH = 1.85 when mobile). Operating the windshield defroster to introduce fresh outside air increased ACH by approximately 0.5–1 ACH during mobile and stationary phases. During the mobile phase (average speed of 23 miles per hour (mph)), the combination of the defroster and two open ceiling hatches (with a powered fan on the rear hatch) yielded an ACH of approximately 9.3 ACH. A mobile phase ACH of 12.4 was achieved by the combination of the defroster, ceiling hatches, and six passenger windows open 2 inches in the middle area of the bus. A maximum mobile phase ACH of 22.1 was observed by using the defroster, open ceiling hatches, driver window open 4 inches, and every other passenger window open 2 inches. For reference, ACHs recommended in patient care settings where patients are being treated for airborne infectious diseases range from 6 to ≥12 ACHs. The results indicate that practical ventilation protocols on school buses can achieve air change rates thought to be capable of reducing airborne viral transmission to the bus driver and student passengers during the COVID-19 pandemic. [ABSTRACT FROM AUTHOR]

Problems caused by overcrowding and the simple need to breathe represent one of the major consequences of medical racism. With few exceptions, histories of epidemics, disease prevention, and sanitation often focus on municipal reform efforts to clean up gritty urban centers from London to Paris to New York. This article traces how concerns about ventilation emerged during the transatlantic slave trade and continued to be a problem for Black people throughout the eighteenth, nineteenth and twentieth centuries. The article emphasizes that Black people were not just the victims of medical racism but initiated many crusades in the United States to promote better ventilation throughout the twentieth century. This article highlights the work of Black reformers, doctors, and thinkers who fought to create healthy living conditions for Black people., (© The Author(s) 2024. Published by Oxford University Press. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

The systemic steroids are recommended for cases with refractory septic shock or severe acute respiratory distress syndrome. Although systemic glucocorticoids help to resolve inflammation and treat cytokine storm, the time course for steroid use and which patients benefit from using systemic corticosteroids is unclear. In this study, we aimed to evaluate the therapeutic effect of corticosteroids in COVID-19 patients. Electronic medical records of hospitalized patients (n=7,980) from 178 hospitals across United States for confirmed COVID-19 between January 1st 2020 and May 8th 2020 were reviewed. Of the 7,980 patients, 3,951 (49.5%) were female and 4,029 (50.5%) were male. The mean age was 57.4 ± 19 years. Fifteen percent (n=1,219) died in hospital or were discharged to hospice care. Seventy-two percent (n=5,774) required non-ICU level of care, while 28% (n=2,206) of patients required ICU, and of those 1,157 (14.5%) needed ventilator support. The mean length of stay in the hospital was 6 days (range 0 -- 84 days). Fourteen percent (n=1111) of patients received at least one dose of systemic steroids during hospitalization. Sixty precent of those had ICU level of care with 435 (39%) requiring ventilator support. Overall, the use of corticosteroids was associated with increased mortality (OR=1.273; p=0.0160) and 3.53 days longer hospital stay (p<0.0001). The corticosteroid exposed group was also noted to progress to a higher level of care and have longer time on a ventilator when compared with the patients who did not receive steroids. The length of hospital stay and mortality was higher especially in severe/critical patients. Based on these results, we recommend cautious use of corticosteroids in COVID-19. The etiology behind this association is still unclear and presents an area for future research. [ABSTRACT FROM AUTHOR]

The current national coverage determinations (NCDs) for noninvasive ventilation for patients with thoracic restrictive disorders, COPD, and hypoventilation syndromes were formulated in 1998. New original research, updated formal practice guidelines, and current consensus expert opinion have accrued that are in conflict with the existing NCDs. Some inconsistencies in the NCDs have been noted, and the diagnostic and therapeutic technology has also advanced in the last quarter century. Thus, these and related NCDs relevant to bilevel positive airway pressure for the treatment of OSA and central sleep apnea need to be updated to ensure the optimal health of patients with these disorders. To that end, the American College of Chest Physicians organized a multisociety (American Thoracic Society, American Academy of Sleep Medicine, and American Association for Respiratory Care) effort to engage experts in the field to: (1) identify current barriers to optimal care; (2) highlight compelling scientific evidence that would justify changes from current policies incorporating best evidence and practice; and (3) propose suggestions that would form the basis for a revised NCD in each of these 5 areas (thoracic restrictive disorders, COPD, hypoventilation syndromes, OSA, and central sleep apnea). The expert panel met during a 2-day virtual summit in October 2020 and subsequently crafted written documents designed to achieve provision of "the right device to the right patient at the right time." These documents have been endorsed by the participating societies following peer review and publication in CHEST and will be used to inform efforts to revise the current NCDs. [ABSTRACT FROM AUTHOR]

Exposure to noise—or unwanted sound—is considered a major public health issue in the United States and internationally. Previous work has shown that even acute noise exposure can influence physiological response in humans and that individuals differ markedly in their susceptibility to noise. Recent research also suggests that specific acoustic properties of noise may have distinct effects on human physiological response. Much of the existing research on physiological response to noise consists of laboratory studies using very simple acoustic stimuli—like white noise or tone bursts—or field studies of longer-term workplace noise exposure that may neglect acoustic properties of the noise entirely. By using laboratory exposure to realistic heating, ventilation, and air conditioning (HVAC) noise, the current study explores the interaction between acoustic properties of annoying noise and individual response to working in occupational noise. This study assessed autonomic response to two acoustically distinct noises while participants performed cognitively demanding work. Results showed that the two HVAC noises affected physiological arousal in different ways. Individual differences in physiological response to noise as a function of noise sensitivity were also observed. Further research is necessary to link specific acoustic characteristics with differential physiological responses in humans. [ABSTRACT FROM AUTHOR]

COVID-19 is ravaging US prisons. Prison residents and staff must be prioritized for vaccination, but a rapidly mutating virus and high rates of continued spread require an urgent, coordinated public health response. Based on knowledge accumulated from the pandemic thus far, we have identified 10 pressing public health priorities for responding to COVID-19 in prisons: (1) accelerate population reduction coupled with community reentry support, (2) improve prison ventilation systems, (3) ensure appropriate mask use, (4) limit transfers between facilities, (5) strengthen partnerships between public health departments and prison leadership, (6) introduce or maintain effective occupational health programs, (7) ensure access to advance care planning processes for incarcerated patients and delineation of patient health care rights, (8) strengthen partnerships between prison leadership and incarcerated people, (9) provide emergency mental health support for prison residents and staff, and (10) commit to public accountability and transparency. Dedicated prison leaders cannot accomplish these public health priorities alone. We must mobilize prison leaders, staff, and residents; public health departments; community advocates; and policymakers to work together to address the pandemic's outsized impact in US prisons. [ABSTRACT FROM AUTHOR]

Objective: To describe coronavirus disease 2019 (COVID-19) mitigation measures in workplaces of employed US blood donors by industry and work arrangement., Methods: During May-December 2021, blood donors responded to a survey; we describe the distribution of reported workplace mitigation measures by industry and work arrangement, organized using the hierarchy of controls., Results: Of 53,433 respondents representing 21 industries, ventilation upgrades were reported by 4%-38% of respondents (overall: 20%); telework access ranged from 14%-80% (53% overall). Requiring masks (overall: 84%; range: 40%-94%), physical distancing (77%; 51%-86%), paid leave for illness (70%; 38%-87%), and encouraging vaccination (61%; 33%-80%) were common. Independent workers reported fewer mitigation measures than those in traditional employment settings., Conclusions: Mitigation measures varied by industry and work arrangement. Some mitigation measures may be challenging to implement or irrelevant in certain industries, supporting the idea that mitigation is not a one-size-fits-all strategy., Policy Implications: Tailored strategies to mitigate workplace risks of disease transmission are vital. Strategies should rely on effective methods for identifying workplace controls (e.g., through the hierarchy of controls) and account for industry-specific characteristics and workplace environments., (© 2024 Wiley Periodicals LLC.)

Since the beginning of the COVID-19 pandemic, a vigorous public health discussion has arisen over indoor air quality and ventilation. In popular press articles, bestselling books, and the US Environmental Protection Agency's recently announced Clean Air in Buildings Challenge, scholars and policy experts have claimed that improved ventilation systems can lead to better productivity and performance. By reevaluating those claims in light of the history of public health in Great Britain and the United States, we found that better ventilation has frequently been proposed as a cost-effective and nonintrusive means of improving health in institutions experiencing structural and environmental public health problems. Furthermore, our examination of efforts to provide ventilation for enslaved people, incarcerated people, and the urban poor revealed a consistent lack of government regulation and a disassociation of air quality concerns from broader environmental, social, and economic realities. By continuing to ignore these broader contexts, current ventilation efforts risk repeating this pattern. ( Am J Public Health . 2024;114(8):798-804. https://doi.org/10.2105/AJPH.2024.307670).

Introduction: Medical and physician assistant (PA) students are often required to have Basic Life Support (BLS) education prior to engaging in patient care. Given the potential role of students in resuscitations, it is imperative to ensure that current BLS training prepares students to provide effective cardiopulmonary resuscitation (CPR). The objective of this study was to assess whether current BLS training produces student providers who can deliver BLS in an American Heart Association (AHA) guideline-adherent manner. Methods: Students at a US medical school were recruited by convenience sampling. BLS performance immediately following a standard AHA BLS training course was evaluated during a twominute CPR cycle using manikins. We also collected information on demographics, previous BLS training attendance, perceived comfort in providing CPR, and prior experiences in healthcare and providing or observing CPR. Results: Among 80 participants, we found that compression rate, depth, and inter-compression recoil were AHA guideline-adherent for 90.0%, 68.8%, and 79.3% of total compression time, respectively. Mean hands-off time was also within AHA guidelines. Mean number of unsuccessful ventilations per cycle was 2.2. Additionally, 44.3% of ventilations delivered were of adequate tidal volume, 12.2% were excessive, and 41.0% were inadequate. Past BLS course attendance, prior healthcare certification, and previous provision of real-life CPR were associated with improved performance. Conclusion: Following BLS training, medical and PA students met a majority of AHA compressions guidelines, but not ventilations guidelines, for over 70% of CPR cycles. Maintaining compression depth and providing appropriate ventilation volumes represent areas of improvement. Conducting regular practice and involving students in real-life CPR may improve performance. [ABSTRACT FROM AUTHOR]

People with chronic obstructive pulmonary disease frequently seek care for acute exacerbations, which are associated with significant morbidity and mortality. Therefore, it is crucial for physicians to understand how to assess and treat these patients appropriately. [ABSTRACT FROM AUTHOR]

With the coronavirus disease 2019 (COVID-19) pandemic, one of the major concerns is the direct medical cost and resource use burden imposed on the US health care system. We developed a Monte Carlo simulation model that represented the US population and what could happen to each person who got infected. We estimated resource use and direct medical costs per symptomatic infection and at the national level, with various "attack rates" (infection rates), to understand the potential economic benefits of reducing the burden of the disease. A single symptomatic COVID-19 case could incur a median direct medical cost of $3,045 during the course of the infection alone. If 80 percent of the US population were to get infected, the result could be a median of 44.6 million hospitalizations, 10.7 million intensive care unit (ICU) admissions, 6.5 million patients requiring a ventilator, 249.5 million hospital bed days, and $654.0 billion in direct medical costs over the course of the pandemic. If 20 percent of the US population were to get infected, there could be a median of 11.2 million hospitalizations, 2.7 million ICU admissions, 1.6 million patients requiring a ventilator, 62.3 million hospital bed days, and $163.4 billion in direct medical costs over the course of the pandemic. [ABSTRACT FROM AUTHOR]

Rationale: Patients receiving prolonged mechanical ventilation experience low survival rates and incur high healthcare costs. However, little is known about how to optimally organize and manage their care.Objectives: To identify a set of effective care practices for patients receiving prolonged mechanical ventilation.Methods: We performed a focused ethnographic evaluation at eight long-term acute care hospitals in the United States ranking in either the lowest or highest quartile of risk-adjusted mortality in at least four of the five years between 2007 and 2011.Measurements and Main Results: We conducted 329 hours of direct observation, 196 interviews, and 39 episodes of job shadowing. Data were analyzed using thematic content analysis and a positive-negative deviance approach. We found that high- and low-performing hospitals differed substantially in their approach to care. High-performing hospitals actively promoted interdisciplinary communication and coordination using a range of organizational practices, including factors related to leadership (e.g., leaders who communicate a culture of quality improvement), staffing (e.g., lower nurse-to-patient ratios and ready availability of psychologists and spiritual care providers), care protocols (e.g., specific yet flexible respiratory therapy-driven weaning protocols), team meetings (e.g., interdisciplinary meetings that include direct care providers), and the physical plant (e.g., large workstations that allow groups to interact). These practices were believed to facilitate care that is simultaneously goal directed and responsive to individual patient needs, leading to more successful liberation from mechanical ventilation and improved survival.Conclusions: High-performing long-term acute care hospitals employ several organizational practices that may be helpful in improving care for patients receiving prolonged mechanical ventilation. [ABSTRACT FROM AUTHOR]

BACKGROUND: Noninvasive ventilation (NIV) is commonly used to support children with respiratory failure, but detailed patterns of real-world use are lacking. The aim of our study was to describe use patterns of NIV via electronic medical record (EMR) data. METHODS: We performed a retrospective electronic chart review in a tertiary care pediatric ICU in the United States. Subjects admitted to the pediatric ICU from 2014 to 2017 who were mechanically ventilated were included in the study. RESULTS: The median number of discrete device episodes, defined as a time on support without interruption, was 20 (interquartile range [IQR] 8-49) per subject. The median duration of bi-level positive airway pressure (BPAP) support prior to interruption was 6.3 h (IQR 2.4-10.4); the median duration of CPAP was 6 h (IQR 2.1-10.4). Interruptions to BPAP had a median duration of 6.3 h (IQR 2-15.5); interruptions to CPAP had a median duration of 8.6 h (IQR 2.2-16.8). Use of NIV followed a diurnal pattern, with 44% of BPAP and 42% of CPAP subjects initiating support between 7:00 PM and midnight, and 49% of BPAP and 46% of CPAP subjects stopping support between 5:00 AM and 10:00 AM. CONCLUSIONS: NIV was frequently interrupted, and initiation and discontinuation of NIV follows a diurnal pattern. Use of EMR data collected for routine clinical care allowed the analysis of granular details of typical use patterns. Understanding NIV use patterns may be particularly important to understanding the burden of pediatric ICU bed utilization for nocturnal NIV. To our knowledge, this is the first study to examine in detail the use of pediatric NIV and to define diurnal use and frequent interruptions to support. [ABSTRACT FROM AUTHOR]

The benefits of acute non‐invasive ventilation to treat acidotic exacerbations of chronic obstructive pulmonary disease (COPD) are well‐established. Until recently, the evidence for home mechanical ventilation (HMV) to treat patients with stable COPD had been lacking. This has subsequently been addressed by the application of higher levels of pressure support combined with targeted management of chronic respiratory failure, which demonstrated a reduction in all‐cause mortality. Similarly, the previous trial of home oxygen therapy (HOT) and HMV delivered following an acute exacerbation failed to demonstrate an improvement in outcome. With the focus on patients with persistent hypercapnic respiratory failure in the recovery phase following a life‐threatening exacerbation combined with targeted reduction in carbon dioxide, HOT and HMV (HOT‐HMV) was shown to be clinically effective in reducing the time to readmission or death and cost effective in both the United Kingdom and United States healthcare systems. Future work will need to focus on promoting adherence to home ventilation and novel auto‐titrating ventilator modes to facilitate and optimize the set‐up of overnight ventilatory support in different target population such as COPD patients with obstructive sleep apnoea and COPD patients with episodic nocturnal hypoventilation. [ABSTRACT FROM AUTHOR]

Prescribed burning is an essential tool for forest and rangeland management that requires specific weather conditions to enable the efficient and safe application of fire. Prescribed burning is often limited by the ability to find suitable burn-days that fit within the identified weather parameters that balance good smoke dispersion and erratic fire behaviour. We analysed the sensitivity of the occurrence of widely used weather windows in the southeastern USA to modest changes in how they are defined. This analysis identified the most limiting prescription components and assessed where small changes in the prescription window can yield the greatest gains in additional burn-days. In the growing season (April–September), adjustments to mixing height offered the greatest such opportunity: a 12.5% increase in the upper-limit yields ~25% more burn-days during this period. During the dormant season (November–January), a 12.5% change in the upper-limit of transport wind yields ~20% more burn-days. Performing this analysis on the ventilation index revealed that comparable increases in burn-days were available by changing its upper limits. These results help inform ongoing discussions on potential changes to regional prescribed burn weather parameters that might help meet smoke management and treatment objectives in the southeastern USA and more broadly. Prescribed fire managers face increasing challenges in meeting extensive area-treated objectives. Amid discussion of the trade-offs involved with relaxing burn weather parameters, our analysis revealed the potential for small changes to result in larger expansions of the opportunities to burn by a factor of 2. These expansions were mostly driven by relaxing the upper limits on mixing height in the growing season and on transport wind in the dormant season. [ABSTRACT FROM AUTHOR]

The authors convey their concerns on whether the distribution of cardboard baby boxes is a public health benefit or concern. Topics discussed include distribution of baby boxes by the Social Insurance Institution of Finland, Kela in the 1930s, concerns raised by the safety of the baby box for infant sleep, and issues raised by the height of the cardboard box walls about mothers' breastfeeding.

In most major cities of China, commuters inevitably spend a considerable amount of time in vehicle cabins due to the escalation of traffic congestion and a rapidly increasing vehicle population. The in-vehicle microenvironment that is in close proximity to traffic emission sources is at particular risk of increased exposure to traffic-related air pollutants (TRAPs). In this study, a mobile measurement campaign was carried out to investigate in-vehicle exposure to TRAPs in China where the elevated level of TRAPs has drawn worldwide attention in recent years. Our analysis demonstrates that vehicle ventilation mode (i.e., mechanical ventilation, natural ventilation, hybrid ventilation, and infiltration) played a critical role in determining the level of in-vehicle exposure. Although the outside air (OA) mode of mechanical ventilation provided adequate air exchange to passengers, the average in-vehicle PM 2.5 and UFP concentrations (119 μg/m3 and 97,227 cm−3 on freeway, and 93 μg/m3 and 42,829 cm−3 on local roadway) during a 20-min sampling period were observed at the level that are markedly greater than those from studies conducted in the U.S., posing a serious health threat to vehicle occupants. We elaborated how our results collected in China with a significantly more polluted on-road environment differ from existing studies in terms of ventilation and driving conditions. In addition, we made the first effort to examine in-vehicle exposure under hybrid ventilation that is a common ventilation practice in everyday commute to potentially reduce symptoms similar to sick building syndrome (SBS). Our data indicate that vehicle occupants under hybrid ventilation are at much greater risk of TRAPs exposure if operating in a polluted on-road environment, and we call for future research on automated ventilation system with advanced window control especially for vans and buses with a large cabin volume. • A mobile field campaign was carried out to study in-vehicle exposure in China. • Vehicle ventilation mode played a critical role in determining the level of in-vehicle exposure. • The observed particle concentrations in China are much greater than those from U.S. studies. • UFP concentration showed much steeper exponential decline with time than that of PM 2.5 under RC. • Vehicle occupants can be at greater risk of TRAPs exposure under hybrid ventilation. [ABSTRACT FROM AUTHOR]

Proper ventilation of residences is essential for occupant health and comfort, and is responsible for a significant portion of energy consumption in homes. This study examines a method for providing adequate ventilation in homes while reducing energy consumption and peak demand: "smart" control of ventilation through sensing of occupancy and modulation of ventilation fans. We first conducted a detailed simulation study of advanced California homes with several occupancy-based ventilation control strategies. We then look at how general these results are nationally through a second simulation campaign in 15 ASHRAE climate zones. All simulations compared equivalent indoor air quality situations and assessed energy savings benefits. A key difference from previous demand-controlled ventilation strategies is that our study includes the effects of building related contaminants that are continuously emitted, irrespective of occupancy status, consistent with the requirements in ASHRAE Standard 62.2–2016. Under this new assumption, it is very difficult to extract substantial energy savings using only occupancy sensing. For the baseline strategy, savings were less than 10% of ventilation energy and sometimes negative in all cases analyzed other than leakier 2-story homes. Addition of a pre-occupancy flush period increases savings somewhat, but savings are still less than 15% other than in 2-story leakier homes. • Accounting of exposure to pollutants emitted by a home is crucial for accurately determining the efficacy of a given strategy. • Large savings are very difficult to achieve through occupancy-based smart ventilation in residences. • Efficacy of occupancy-based smart ventilation strategies is very climate-dependent and most effective in the hottest climates. • Efficacy of strategies is highly dependent on concentrations to which occupants are exposed immediately upon returning home. [ABSTRACT FROM AUTHOR]

In May 2023 the World Health Organization (WHO) Director General announced the "end" of the COVID-19 Public Health Emergency of International Concern. Although the scale of the pandemic was unprecedented in living memory, it had not been unforeseen. Previous outbreaks of viral respiratory disease have shown important lessons regarding the need to protect healthcare workers (HCW), and research has also been undertaken into the relative effectiveness of control measures and their resource implications. Relevant guidance for worker protection, including HCW protection, which existed at the onset of the COVID-19 pandemic was disregarded both at international and national governmental levels. In many countries there were significant systemic flaws in strategy, culture, and resource availability, and hence in overall preparedness. When the pandemic struck, many experts and organizations advocated a precautionary approach with regard to worker protection, consistent with good occupational hygiene science, practice, and standards. In many Asian countries, protective measures were relatively stringent. However, many workers were left unprotected especially as the WHO, the United States, the United Kingdom, and other governments did not pursue adequate COVID-19 protective measures at work. As the pandemic progressed, improvements in protection were patchy. A notable lack of protection arose from the underestimation of the contribution of aerosol exposure to infection risks, particularly among HCWs providing routine care of potentially infectious patients. A disciplined strategy of source control, pathway control (such as ventilation), and receptor control notably Respiratory Protective Equipment is needed, as well as worldwide vaccination, to contend with this pandemic. Control measures appropriate to the risk of infections transmitted through the air will remain necessary in the longer term, as well as adaptations in the workplace to take account of long-term COVID-19 morbidity and new work practices., (© The Author(s) 2023. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.)

Objectives Workers using flavoring formulations containing diacetyl and 2,3-pentanedione may be at risk of inhalational exposure, as these volatile hazardous chemicals are emitted from the bulk material, especially at elevated temperatures. However, flavoring formulations that contain diacetyl and 2,3-pentanedione might not list these ingredients because they are generally recognized as safe to ingest, may be part of a proprietary mixture deemed a trade secret, or may not be required to be listed if they are present at <1% composition. The objective of this study was to investigate whether potential inhalational hazards present in flavoring samples were reported as chemical ingredients on their corresponding safety data sheets (SDSs). Methods A convenience sample of 26 bulk liquid flavorings obtained from two coffee roasting and packaging facilities in the USA was analyzed for 20 volatile organic chemicals present in the headspaces of vials containing flavoring liquids using gas chromatography-mass spectrometry. Flavoring samples were included in the study if headspace analysis results and SDSs were available. Flavoring samples included hazelnut, French vanilla, amaretto, chocolate, and caramel as well as some flavoring mixtures containing added fruit flavors such as cherry and raspberry. The presence of a chemical in the flavoring formulation was then compared to the ingredient list on the SDSs. Results All the flavoring SDSs contained trade secret designations. None of the SDSs listed diacetyl or 2,3-pentanedione. Headspace analyte concentrations revealed that diacetyl was present in 21 of 26 samples (81%) with a maximum concentration of 5.84 × 104 µg m−3 in flavor 18 (caramel). 2,3-Pentanedione was present in 15 flavors (58%) with a maximum concentration of 3.79 × 105 µg m−3 in flavor 24 (oatmeal cookies). Conclusions A majority of the flavorings tested had diacetyl, 2,3-pentanedione, or both as volatile constituents in the headspace. These chemicals were not listed on the SDSs, but inclusion of diacetyl and 2,3-pentanedione on SDSs would serve to protect downstream users from unrecognized exposure and potential respiratory disease. The headspace technique presented here is a viable tool to rapidly screen for volatile hazardous chemicals that may be present in flavoring formulations. Facilities that use flavorings should be aware that constituents in flavorings may present a potential inhalational hazard even if not identified as such by the SDS. A precautionary approach is warranted when working with flavorings, including exposure monitoring and effective exposure control strategies such as containment and local exhaust ventilation. [ABSTRACT FROM AUTHOR]

The objectives were to compare capital costs of building and installation of 7 ventilation systems for adult lactating dairy cow housing and evaluate the energy use and operating cost between systems. A cost model comprising stochastic and parametric modules was created to estimate the number of fans operating each day based on temperature set points; annual profiles of daily maximum, minimum, and average temperatures; ramping functions to transition between seasons; and weather data from 7 locations in the United States. Costs were described as US$ per stall per year and operating costs as US$ (kW·h) per stall per year. Building costs amoritized over 10 yr ranged from $246 to $318, where a 16-row cross-ventilated design had the minimum cost and a hybrid design incorporating elements of tunnel and natural ventilation had the maximum cost. Lowering the summer temperature set point from 22.2 to 18.0°C to potentially improve heat abatement for high-producing cows increased cost by $10.10 (101.0 kW·h). On average, an exponential ramping function for transitioning between seasons cost $55.40 (554 kW·h) compared with $61.40 (614 kW·h) for a linear function. A tunnel barn ranged from $79.40 (794 kW·h) to $212.30 (2123 kW·h), and a natural design ranged from $32.60 (326 kW·h) to $81.80 (818 kW·h) in operating costs due to fan selection alone. Cross-ventilated barns benefitted from economies of scale and had similar operating costs as naturally ventilated barns in larger facilities. On average, mechanical systems cost twice as much to operate as natural systems, and operating costs in hotter US climates were approximately double those in milder climates. Selecting a fan with low energy efficiency can increase the operating cost of any ventilation system approximately 2-fold, making fan choice a critical design element. [ABSTRACT FROM AUTHOR]

Heating and cooling of buildings consume approximately 15% of all energy used in the United States. Such a large energy demand is primarily due to heating and cooling of the entire building space to temperature setpoints usually between 21.1 °C (70 °F) and 23.9 °C (75 °F). However, even with such a narrow range of temperature setpoints, more than 20% of the occupants do not feel thermally comfortable due to individual differences (e.g. age, gender, clothing, or physiology). The personal thermal management techniques, which create a local thermal envelope around a human body instead of heating or cooling the entire building space, have the potential to greatly reduce the building energy consumption and to enhance thermal comfort of individuals. In this study, a portable thermoelectric energy conversion unit (TECU) that converts electricity into cooling and heating energy is developed. The TECU supplies cool air (in the cooling mode) or warm air (in the heating mode) to regulate the thermal comfort of a human body. The cool or warm air is supplied through a tree-like rubber tube network that is knitted into a thermoregulatory undergarment. To achieve a cooling/heating target that provides satisfactory thermal comfort, the required cooling/heating power supply from the TECU is determined first while a theoretical model is then developed to guide the design of the TECU. To minimize the TECU weight and make it suitable for portable applications, relationships between weight and thermal resistances of commercial off-the-shelf heat sinks are established first, and a method to find the minimal weight of heat sinks for the TECU is then developed. This methodology is also applicable for other applications where heat sink weight needs to be minimized. The thermal manikin tests demonstrate that 24.6 W of personal cooling power and 18.5 W of personal heating power are achieved by using the TECU. [ABSTRACT FROM AUTHOR]

Residential inter-zonal (e.g., between rooms) ventilation is comprised of fresh air infiltration in and exfiltration out of the whole house plus the “fresh” air that is entering (and exiting) the room of interest from other rooms or areas within the house. Clearly, the inter-zone ventilation rate in any room of interest will be greater than the infiltration/exfiltration ventilation rate of outdoor air for the whole house. The purpose of this study is to determine how much greater the inter-zonal ventilation rate is in typical U.S. residences compared to the whole house ventilation rate from outdoor air. The data for this statistical analysis came from HouseDB, a 1995 EPA database of residential ventilation rates. Analytical results indicate that a lognormal distribution provides the best fit to the data. Lognormal probability distribution functions (PDFs) are provided for various inter-zonal ventilation rates for comparison to the PDF for the whole house ventilation rates. All ventilation rates are expressed as air change rates per hour (ACH). These PDFs can be used as inputs to exposure models. This analysis suggests that if one were performing a deterministic analysis for unknown housing stocks in the U.S., a default mean and median ACH values of 0.4/hr and 0.3/hr, respectively, for whole house ventilation would be appropriate; and 0.7/hr and 0.6/hr, respectively, for inter-zonal ventilation. [ABSTRACT FROM AUTHOR]

Packaged air-conditioning systems, such as rooftop units (RTUs), are widely used in small commercial buildings in the United States. Although new regulations and standards require new air-conditioning equipment to have multi-speed supply fan operation, most of the installed units employ fixed-speed supply fans. The electrical energy usage associated with constant volumetric air delivery fan systems is on the order of half the total RTU electrical energy usage because supply fans operate continuously during the occupied periods in commercial buildings for ventilation. In addition, compressors within RTUs typically feature single- or two-stage capacity controls leading to frequent unit cycling and thus, deteriorated performance in energy efficiency. This paper presents relatively comprehensive assessment results for three RTU variable-speed retrofit options: 1) retrofits of fixed-speed supply fans with variable-speed fans for single-compressor-speed units, 2) replacement of existing fixed-speed RTUs with RTUs having two-speed compressors with variable-speed supply fans and 3) retrofits of RTUs with new RTUs that incorporate variable-speed compressors and fans (indoor and outdoor). The assessment study involves parametric simulations across different building types and locations in the U.S. to understand the performance variation with respect to location and building use. Performance improvements in terms of energy efficiency, operation cost and indoor comfort delivery for the various retrofit options are demonstrated compared to conventional single-stage RTUs with constant speed supply fans. The assessment results show that all three retrofit options offer significant fan energy savings, but much smaller savings potential for compressor and condenser fan electricity consumption. The variable-speed-unit retrofit provides the highest cost savings potentials, ranging from 40 to 250 $ per rated cooling ton per year depending on the building type and location. In addition to efficiency and economic benefits, the two-stage-unit and variable-speed-unit retrofits also lead to improved indoor humidity regulation performance due to reduced unit cycling. [ABSTRACT FROM AUTHOR]

Natural ventilation is used to cool buildings and cut energy costs by inducing airflow through building openings without the use of mechanical ventilation and cooling systems. However, prior research has documented increased introduction of particles into indoor environments that are naturally ventilated, with associated health consequences. The recently updated ASHRAE Standard 62.1–2019: Ventilation for Acceptable Indoor Air Quality Natural Ventilation Procedure (NVP) prescribes opening sizes as a function of occupant density and geometry for use as a ventilation strategy, a change from the previous standard. The current work quantifies the indoor air quality impacts of implementing the Standard 62.1–2019 Natural Ventilation Procedure in the United States and compares it to the 62.1-specified ventilation rate procedure. This is done via coupled transient simulation of CONTAM 3.4 and EnergyPlus 9.1. Three pollutant classes were identified to represent a broad range of contaminants: outdoor-generated pollutants, pollutants generated indoors by humans, and pollutants generated indoors by the building itself. With boundary conditions from measured weather and outdoor pollutant data for 13 representative locations throughout the U.S., our modeling first found 41%–185% annual average increase in ventilation rates over its mechanical counterpart if the NVP is used across the geometries and occupant densities in the Standard. Due to elevated ventilation rates, the Natural Ventilation Procedure reduced building-generated and occupant-generated contaminant concentrations during occupied hours by an average of 17%–61% compared to the ventilation rate procedure. Outdoor-generated fine particles averaged 2.1–2.5 times the concentrations indoors when using the NVP as compared to mechanical ventilation with a MERV-8 filter and 7.8–10.4 times the concentration of a mechanical system with a MERV-13 filter. Both ventilation rates and concentrations were substantially climate-specific and somewhat window geometry-specific. We further showed that increased filtration is needed in many cases to keep up with increased effective NVP rates in the 2019 Standard if acceptable levels of indoor particles are to be achieved, and we offer suggestions for improving the Standard. • ASHRAE Standard 62.1–2019 prescribes natural ventilation rates significantly greater than mechanical prescriptions. • Predicted concentrations of pollutants generated indoors were 39–83% of mechanical ventilation concentrations. • Predicted concentrations of fine particle from outdoors were as much as 10 times greater than mechanical. • Filtration efficiency in mechanical systems drastically affects particle concentrations. • Several improvements to ASHRAE 62.1 Natural Ventilation Procedure are suggested. [ABSTRACT FROM AUTHOR]

Based on a review of literature published in refereed archival journals, ventilation rates in classrooms often fall far short of the minimum ventilation rates specified in standards. There is compelling evidence, from both cross-sectional and intervention studies, of an association of increased student performance with increased ventilation rates. There is evidence that reduced respiratory health effects and reduced student absence are associated with increased ventilation rates. Increasing ventilation rates in schools imposes energy costs and can increase heating, ventilating, and air-conditioning system capital costs. The net annual costs, ranging from a few dollars to about 10 dollars per person, are less than 0.1% of typical public spending on elementary and secondary education in the United States. Such expenditures seem like a small price to pay given the evidence of health and performance benefits. [ABSTRACT FROM AUTHOR]

Low ventilation rates ( VRs) in schools have been associated with absenteeism, poorer academic performance, and teacher dissatisfaction. We measured VRs in 37 recently constructed or renovated and mechanically ventilated U.S. schools, including LEED and EnergyStar-certified buildings, using CO2 and the steady-state, build-up, decay, and transient mass balance methods. The transient mass balance method better matched conditions (specifically, changes in occupancy) and minimized biases seen in the other methods. During the school day, air change rates ( ACRs) averaged 2.0±1.3 hour−1, and only 22% of classrooms met recommended minimum ventilation rates. HVAC systems were shut off at the school day close, and ACRs dropped to 0.21±0.19 hour−1. VRs did not differ by building type, although cost-cutting and comfort measures resulted in low VRs and potentially impaired IAQ. VRs were lower in schools that used unit ventilators or radiant heating, in smaller schools and in larger classrooms. The steady-state, build-up, and decay methods had significant limitations and biases, showing the need to confirm that these methods are appropriate. Findings highlight the need to increase VRs and to ensure that energy saving and comfort measures do not compromise ventilation and IAQ. [ABSTRACT FROM AUTHOR]

In January 2007, the National Institute for Occupational Safety and Health (NIOSH) conducted a field study to evaluate process specific emissions during the production of ENMs. This study was performed using the nanoparticle emission assessment technique (NEAT). During this study, it was determined that ENMs were released during production and cleaning of the process reactor. Airborne concentrations of silver, nickel, and iron were found both in the employee's personal breathing zone and area samples during reactor cleaning. At the completion of this initial survey, it was suggested that a flanged attachment be added to the local exhaust ventilation system.  NIOSH re-evaluated the facility in December 2011 to assess worker exposures following an increase in production rates. This study included a fully comprehensive emissions, exposure, and engineering control evaluation of the entire process. This study made use of the nanoparticle exposure assessment technique (NEAT 2.0). Data obtained from filter-based samples and direct reading instruments indicate that reactor cleanout increased the overall particle concentration in the immediate area. However, it does not appear that these concentrations affect areas outside of the production floor. As the distance between the reactor and the sample location increased, the observed particle number concentration decreased, creating a concentration gradient with respect to the reactor. The results of this study confirm that the flanged attachment on the local exhaust ventilation system served to decrease exposure potential.  Given the available toxicological data of the metals evaluated, caution is warranted. One should always keep in mind that occupational exposure levels were not developed specifically for nanoscale particles. With data suggesting that certain nanoparticles may be more toxic than the larger counterparts of the same material; employers should attempt to control emissions of these particles at the source, to limit the potential for exposure. [ABSTRACT FROM PUBLISHER]

Alaska Native children experience high rates of respiratory infections and conditions. Household crowding, indoor smoke, lack of piped water, and poverty have been associated with respiratory infections. We describe the baseline household characteristics of children with severe or chronic lung disease participating in a 2012-2015 indoor air study. We monitored indoor PM2.5, CO2, relative humidity %, temperature, and VOCs and interviewed caregivers about children's respiratory symptoms. We evaluated the association between reported children's respiratory symptoms and indoor air quality indicators using multiple logistic regression analysis. Compared with general US households, study households were more likely overcrowded 73% (62%-82%) vs 3.2% (3.1%-3.3%); had higher woodstove use as primary heat source 16% (9%-25%) vs 2.1% (2.0%-2.2%); and higher proportion of children in a household with a smoker 49% (38%-60%) vs 26.2% (25.5%-26.8%). Median PM2.5 was 33 μg/m3. Median CO2 was 1401 ppm. VOCs were detectable in all homes. VOCs, smoker, primary wood heat, and PM2.5>25 μg/m3 were associated with higher risk for cough between colds; VOCs were associated with higher risk for wheeze between colds and asthma diagnosis. High indoor air pollutant levels were associated with respiratory symptoms in household children, likely related to overcrowding, poor ventilation, woodstove use, and tobacco smoke. [ABSTRACT FROM AUTHOR]

Supraglottic airway devices are increasingly used during the resuscitation of out-of-hospital cardiac arrest (OHCA) patients in the United States and worldwide. In this study, we aimed to compare the neurologic outcomes of OHCA patients managed with the King Laryngeal Tube (King LT) to the neurologic outcomes of patients managed with the iGel. We used the Cardiac Arrest Registry to Enhance Survival (CARES) public use research dataset for our analysis. Non-traumatic OHCA cases with attempted EMS resuscitation enrolled from 2013-2021 were included. We used two-level mixed effects multivariable logistic regression analyses with treating EMS agency as the random effect to determine the association between supraglottic airway device and outcome. The primary outcome was survival with a Cerebral Performance Category (CPC) score of 1 or 2 at discharge. Secondary outcomes included survival to hospital admission and survival to hospital discharge. Age, sex, calendar year of OHCA, initial ECG rhythm, witnessed status (unwitnessed, bystander witnessed, 9-1-1 responder witnessed), bystander CPR, response interval, and OHCA location (private/home, public, institutional) were used as covariables. In comparison to use of the King LT, use of the iGel was associated with greater neurologically favorable survival (aOR: 1.45 [1.33, 1.58]). In addition, use of the iGel was associated with greater survival to hospital admission (1.07 [1.02, 1.12]) and survival to hospital discharge (1.35 [1.26, 1.46]). This study adds to the body of literature suggesting that use of the iGel during OHCA resuscitation is associated with better outcomes than use of the King LT. [ABSTRACT FROM AUTHOR]

[Display omitted] • The research team examined the effects of indoor environmental variables on absence rates in elementary schools. • Higher classroom ventilation rates significantly reduced illness-related absences. • Higher concentrations of indoor long-term monitored PM 2.5 were significantly associated with increased illness-related absences. • Although mechanically ventilated classrooms had relatively low indoor PM 2.5 , more rigorous control of indoor particles was still beneficial. This study monitored indoor environmental data in 144 classrooms in 31 schools in the Midwestern United States for two consecutive days every fall, winter, and spring during a two-year period; 3,105 pupils attended classrooms where the measurements were conducted. All classrooms were ventilated with mechanical systems that had recirculation; there were no operable exterior windows or doors. The daily absence rate at the student level and demographic data at the classroom level were collected. The overall mean ventilation rate, using outdoor air, was 5.5 L/s per person (the corresponding mean carbon dioxide concentrations were < 2,000 ppm), and the mean indoor PM 2.5 was 3.6 μg/m3. The annual illness-related absence rate at the classroom level was extracted from the student-level absence data and regressed on measured indoor environmental parameters. Significant associations were found. Every 1 L/s per person increase in ventilation rate was associated with a 5.59 decrease in days with absences per year. This corresponds to a 0.15% increase in the annual daily attendance rate. Every additional 1 μg/m3 of indoor PM 2.5 was associated with a 7.37 increase in days with absences per year. This corresponds to a 0.19% decrease in the annual daily attendance rate. No other relationships were significant. Present results agree with the previously demonstrated benefits of reduced absence rates when classroom ventilation is improved and provide additional evidence on the potential benefits of reducing indoor inhalable particles. Overall, reduced absence rates are expected to provide socioeconomic benefits and benefits for academic achievements, while higher ventilation rates and reduced particle levels will also contribute to reduced health risks, including those related to airborne respiratory pathogens. [ABSTRACT FROM AUTHOR]

Competing Interests: Conflict of InterestThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

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. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to examine the influence of the heating, ventilation, and air-conditioning method on voice function following a voicing task using ecologically valid offices, one with radiant HVAC and one with forced air. Method: A total of 12 consented participants (6 women, 6 men) narrated a video in each of 4 environmental conditions in a within-between repeated-measures design. Acoustic data were collected with an ambulatory phonation monitor and perceived phonatory effort was determined following the voicing task. Data were analyzed using a within-between repeated-measures analysis of variance with significance set at α < .05. Results: Perceived phonatory effort did not differ between environments; however, a significant difference in vocal amplitude between 2 trials was identified for the male participants and physiologically significant differences in vocal amplitude were identified for male and female participants. Conclusions: The findings suggest that perceived phonatory effort may not be a sensitive measure of vocal function differences following a voicing task in ecologically valid office spaces despite significant acoustic findings. Future research should address longer exposure to environmental differences combined with a longer voicing task within ecologically valid work spaces as well as the recruitment of participants who have particular vulnerability to environmental perturbations. [ABSTRACT FROM AUTHOR]

In the early decades of the twentieth century, the rapidly growing air-conditioning industry in the United States promised a new form of architectural environment: An odorless, germ-free, and well-tempered interior that aimed at improving the efficiency of production and human conduct. These spaces became pivotal in the conception of modern architecture and were in turn, as this essay suggests, based upon a new understanding of air itself. Perceived no longer as a natural resource but as a compound product, air transformed into an actively configurable material mediating between the human organism and the architectural environment. The various case studies in this essay focus on the specific ways in which scientific knowledge, often backed by the commercial interests of industrial corporations, was employed to dislocate air from the realm of nature and place it in the hands of ventilation engineers. As this modern air became an essential material for the maintenance of modern buildings, the architectural interior gradually became the domain of air-control. [ABSTRACT FROM AUTHOR]

The parameters and conditions that govern the ventilation requirements in residential buildings under current regulations worldwide are not harmonized. The reduction in energy demand and the increase in the thermal comfort in dwellings are mainly conditioned by these parameters. This article reviews and compares the ventilation flow rates in residential buildings in various countries: the United States of America, Germany, France, the United Kingdom, and Spain. It also compares the requirements of these countries with the requirements of the Passivhaus construction standard, which is recommended by the European Union as an example of nearly zero-energy buildings (nZEB). Furthermore, a model for a dwelling is created using TRNSYS software. First, simulations have been performed with the flow rates, ventilation strategies and envelope transmittance required by the regulations of each country. The cooling and heating demands have been obtained for representative cities in different climate zones. With these results, the impact of ventilation parameters in the heating demand of the proposed Spanish dwelling is analyzed. Secondly, the same dwelling has been simulated with the thermal envelope transmittance values recommended by the Passivhaus standard. The ventilation strategies of each country have been maintained. The influence of the ventilation can be observed uninfluenced by other design parameters. It is found that with the current ventilation strategies, the heating and cooling demand values required by Passivhaus can be reached in only a few warm climates. In other cases, the ventilation strategies will need to change, and heat recovery ventilation will be required. [ABSTRACT FROM AUTHOR]

The authors summarize additional important evidence on the effects of the school's indoor environmental quality on academic achievement. They reference an article by SL Michael et al which summarizes research syntheses on the effects on academic achievement of each of the 10 components of the Whole School, Whole Community, Whole Child Framework (WSCC). They suggest that environmental conditions in schools can have a significant effect on student health and academic achievement.

Background: Health care associated transmission of Mycobacterium tuberculosis (TB) is well described. A previous survey of infection control (IC) practices at clinical research sites in low and middle income countries (LMIC) funded by the National Institute of Allergy and Infectious Diseases (NIAID) conducting HIV research identified issues with respiratory IC practices. A guideline for TB IC based on international recommendations was developed and promulgated. This paper reports on adherence to the guideline at sites conducting or planning to conduct TB studies with the intention of supporting improvement.Methods: A survey was developed that assessed IC activities in three domains: facility level measures, administrative control measures and environmental measures. An external site monitor visited each site in 2013-2014, to complete the audit. A central review committee evaluated the site-level survey and results were tabulated. Fisher's exact test was performed to determine whether there were significant differences in practices at sites that had IC officers versus sites that did not have IC officers. Significance was assessed at p

How building stakeholders (e.g. owners, tenants, operators, and designers) understand impacts of Indoor Air Quality ( IAQ) and associated energy costs is unknown. We surveyed 112 stakeholders across the United States to ascertain their perceptions of their current IAQ and estimates of benefits and costs of, as well as willingness to pay for, IAQ improvements. Respondents' perceived IAQ scores correlated with the use of high-efficiency filters but not with any other IAQ-improving technologies. We elicited their estimates of the impacts of a ventilation-filtration upgrade ( VFU), that is, doubling the ventilation rate from 20 to 40 cfm/person (9.5 to 19 l/s/person) and upgrading from a minimum efficiency reporting value 6 to 11 filter, and compared responses to estimates derived from IAQ literature and energy modeling. Minorities of respondents thought the VFU would positively impact productivity (45%), absenteeism (23%), or health (39%). Respondents' annual VFU cost estimates (mean = $257, s.d. = $496, median = $75 per person) were much higher than ours (always <$32 per person), and the only yearly cost a plurality of respondents said they would pay for the VFU was $15 per person. Respondents holding green building credentials were not more likely to affirm the IAQ benefits of the VFU and were less likely to be willing to pay for it. [ABSTRACT FROM AUTHOR]

We assessed the chronic health risks from inhalation exposure to volatile organic compounds ( VOCs) and particulate matter ( PM2.5) in U.S. offices, schools, grocery, and other retail stores and evaluated how chronic health risks were affected by changes in ventilation rates and air filtration efficiency. Representative concentrations of VOCs and PM2.5 were obtained from available data. Using a mass balance model, changes in exposure to VOCs and PM2.5 were predicted if ventilation rate were to increase or decrease by a factor of two, and if higher efficiency air filters were used. Indoor concentrations were compared to health guidelines to estimate percentage exceedances. The estimated chronic health risks associated with VOC and PM2.5 exposures in these buildings were low relative to the risks from exposures in homes. Chronic health risks were driven primarily by exposures to PM2.5 that were evaluated using disease incidence of mortality, chronic bronchitis, and non-fatal stroke. The leading cancer risk factor was exposure to formaldehyde. Using disability-adjusted life years ( DALYs) to account for both cancer and non-cancer effects, results suggest that increasing ventilation alone is ineffective at reducing chronic health burdens. Other strategies, such as pollutant source control and the use of particle filtration, should also be considered. [ABSTRACT FROM AUTHOR]