Health effects of heating, ventilation and air conditioning on hospital patients: a scoping review

Outpacing climate change: adaptation to heatwaves in Europe

Current predictions of climate change impacts rely on conservative assumptions about a lack of adaptation, projecting significantly increased heatwave mortality. However, long-term studies have shown a decline in actual heatwave deaths, raising questions about the underlying mechanisms. We combined Eurostat weekly mortality data (baseline extracted via Seasonal-Trend decomposition by Loess and smoothed through Principal Component Analysis dimension reduction and reconstruction) with economic indicators, Copernicus temperature data since 1950, and ENTSO-E electricity demand data. Panel regression analyzed mortality patterns during weeks with daily temperatures exceeding 22 °C for 2000-2022. During the analyzed period, Europe outpaced climate change, with the capacity to tolerate an additional 1 °C rise every 17.9 years [95% CI 15.3-22.7]. Extending the temperature indicators beyond the prior 3 years did not enhance predictive accuracy, suggesting swift adaptations and historical climate lacked any predictive value. Additionally, increasing economic output, likely driven by infrastructural improvements, especially greater affordability of air conditioning, enabled tolerating each additional 1 °C due to a per capita GDP increase of 19.7 thousand euros [95% CI 14.6-30.3]. Consistently, the increase in cooling energy demand was the strongest in eastern Europe. The findings shed light on the mechanisms driving the observed reduction in heatwave mortality despite the warming climate trend, offering a more plausible basis for extrapolation than assuming a lack of adaptation. The model emphasizes the role of long term economic growth and addressing energy poverty.

The technological assessment of green buildings using artificial neural networks

This study aims to construct a comprehensive evaluation model for efficiently assessing appropriate technologies within green buildings. Initially, an Internet of Things (IoT)-based environmental monitoring system is devised and implemented to collect real-time environmental parameters both inside and outside the building. To evaluate the technical suitability of green buildings, this study employs a multifaceted approach encompassing various criteria, including energy efficiency, environmental impact, economic benefits, user comfort, and sustainability. Specifically, it involves real-time monitoring of environmental parameters, analysis of energy consumption data, and indoor environmental quality indicators derived from user satisfaction surveys. Subsequently, a Multi-Layer Perceptron (MLP) is selected as a conventional artificial neural network (ANN) model, while a Long Short-Term Memory (LSTM) model is chosen as an advanced recurrent neural network model in the realm of deep learning. These models are utilized to process and explore the collected data and assess the technical suitability of green buildings. The dataset comprises physical quantities such as temperature, humidity, and light intensity, as well as economic indicators including energy efficiency and building operating costs. Furthermore, the assessment process considers the building's life cycle assessment and indoor environmental quality factors such as health, comfort, and safety. By incorporating these comprehensive criteria, a holistic evaluation of green building technologies is achieved, ensuring the selected technologies' suitability and effectiveness. The model prediction results demonstrate that the proposed hybrid evaluation model exhibits high accuracy and robust stability in predicting building environmental parameters. For instance, the Root Mean Square Error (RMSE) for temperature prediction is 1.2 °C, the Mean Absolute Error (MAE) is 0.9 °C, and the determination coefficient (R2) reaches 0.95. Similarly, for humidity prediction, the RMSE, MAE, and R2 are 3.5 %, 2.8 %, and 0.88. Compared to the traditional MLP and LSTM models alone, the proposed hybrid model shows significant improvements in predicting building energy consumption, with approximately 15 % and 12 % reductions in RMSE and MAE, respectively, and an increase in R2 values of approximately 7 percentage points. These findings indicate that by amalgamation of the IoT and ANNs, this study successfully establishes a comprehensive model for accurately assessing technologies suitable for green buildings. This approach offers a novel perspective and methodology for the design and evaluation of green buildings.

Human health and the health of Planet Earth go together

The emergence of the planetary health approach was highlighted by the report of The Rockefeller Foundation-Lancet Commission on Planetary Health in 2015 and changed how we comprehend human well-being. The report advocates integrating the health of other living beings and Earth's natural systems as intrinsic components of human health. Drawing on over three decades of experience in respiratory epidemiology and environmental health, this article outlines how my perspective on human health underwent a transformative shift upon reading the abovementioned report. The planetary health approach offers a lens through which human health issues and potential solutions can be understood within the context of the Anthropocene. It addresses the pressing existential challenges arising from humanity's transgression of planetary limits. Embracing the planetary health paradigm within the field of health sciences can catalyze transformative changes essential for cultivating a sustainable and equitable future.

Detection and Analysis of Clostridioides difficile Spores in a Hospital Environment

Clostridioides difficile, due to its long survival time in a hospital environment, is considered to be one of the most frequent factors in healthcare-associated infections. Patient care requires not only rapid and accurate diagnosis, but also knowledge of individual risk factors for infections, e.g., with C. difficile, in various clinical conditions. The goal of this study was to analyse the degree of contamination of a hospital environment with C. difficile spores. Culturing was performed using C diff Banana Broth^TM medium, which enables germination of the spores of these bacteria. Samples were collected from inanimate objects within a hospital environment in a specialist hospital in Poland. The results of the study demonstrated the presence of 18 positive samples of Clostridioides spp. (15.4%). Of these, C. difficile spores were detected in six samples, Clostridioides perfringens in eight samples, Clostridioides sporogenes in two samples and Clostridioides innocuum and Clostridioides baratii in one sample each. Among the six samples of C. difficile, a total of four strains which produce the B toxin were cultured. The binary toxin related to ribotype 027 was not detected in our study. Nosocomial infection risk management is a significant problem, mainly concerning the issues of hygiene maintenance, cleaning policy and quality control, and awareness of infection risk.

Application of a Novel PM Model to Assess the Risk of Clostridioides difficile Infections in Medical Facilities as a Tool for Improving the Quality of Health Services and the Safety of Patients

Infections with multi-drug resistant microorganisms associated with the provision of health services have become an acute problem worldwide. These infections cause increased morbidity as well as mortality and are a financial burden for the healthcare system. Effective risk management can reduce the spread of infections and thus minimize their number in hospitalized patients. We have developed a new approach to the analysis of hazards and of exposure to the risk of adverse events by linking the patient's health record system to the entire infrastructure of the hospital unit. In this study, using the developed model, we focused on infections caused by the Clostridioides difficile bacterium, as they constitute a significant number of nosocomial infections in Poland and worldwide. The study was conducted in a medical facility located in the central part of Poland which provides tertiary care. In the proposed PM model, a risk analysis of hospital acquired infections at the Intensive Care and Anesthesiology Unit combined with the hospital's technical facilities and organizational factors was conducted. The obtained results indicate the most critical events which may have an impact on potential hazards or risks which may result from the patient's stay at the specific ward. Our method can be combined with an anti-problem approach, which minimizes the critical level of infection in order to determine the optimal functioning of the entire hospital unit. Research has shown that in most situations the spread dynamics of nosocomial infections can be controlled and their elimination may be attempted. In order to meet these conditions, the persons responsible for the daily operation of the medical facility and its individual wards have to indicate potential events and factors which present a risk to the hospitalized patients. On the basis of a created spreadsheet directions for improvement may be finally established for all potential events, their frequency may be minimized, and information may be obtained on actions which should be undertaken in a crisis situation caused by the occurrence of a given phenomenon. We believe that the proposed method is effective in terms of risk reduction, which is important for preventing the transmission of multi-drug resistant microorganisms in the hospital environment.

A systematic review and meta-analysis of indoor bioaerosols in hospitals: The influence of heating, ventilation, and air conditioning

OBJECTIVES

To evaluate (1) the relationship between heating, ventilation, and air conditioning (HVAC) systems and bioaerosol concentrations in hospital rooms, and (2) the effectiveness of laminar air flow (LAF) and high efficiency particulate air (HEPA) according to the indoor bioaerosol concentrations.

METHODS

Databases of Embase, PubMed, Cochrane Library, MEDLINE, and Web of Science were searched from 1st January 2000 to 31st December 2020. Two reviewers independently extracted data and assessed the quality of the studies. The samples obtained from different areas of hospitals were grouped and described statistically. Furthermore, the meta-analysis of LAF and HEPA were performed using random-effects models. The methodological quality of the studies included in the meta-analysis was assessed using the checklist recommended by the Agency for Healthcare Research and Quality.

RESULTS

The mean CFU/m3 of the conventional HVAC rooms and enhanced HVAC rooms was lower than that of rooms without HVAC systems. Furthermore, the use of the HEPA filter reduced bacteria by 113.13 (95% CI: -197.89, -28.38) CFU/m3 and fungi by 6.53 (95% CI: -10.50, -2.55) CFU/m3. Meanwhile, the indoor bacterial concentration of LAF systems decreased by 40.05 (95% CI: -55.52, -24.58) CFU/m3 compared to that of conventional HVAC systems.

CONCLUSIONS

The HVAC systems in hospitals can effectively remove bioaerosols. Further, the use of HEPA filters is an effective option for areas that are under-ventilated and require additional protection. However, other components of the LAF system other than the HEPA filter are not conducive to removing airborne bacteria and fungi.

LIMITATION OF STUDY

Although our study analysed the overall trend of indoor bioaerosols, the conclusions cannot be extrapolated to rare, hard-to-culture, and highly pathogenic species, as well as species complexes. These species require specific culture conditions or different sampling requirements. Investigating the effects of HVAC systems on these species via conventional culture counting methods is challenging and further analysis that includes combining molecular identification methods is necessary.

STRENGTH OF THE STUDY

Our study was the first meta-analysis to evaluate the effect of HVAC systems on indoor bioaerosols through microbial incubation count. Our study demonstrated that HVAC systems could effectively reduce overall bioaerosol concentrations to maintain better indoor air quality. Moreover, our study provided further evidence that other components of the LAF system other than the HEPA filter are not conducive to removing airborne bacteria and fungi.

PRACTICAL IMPLICATION

Our research showed that HEPA filters are more effective at removing bioaerosols in HVAC systems than the current LAF system. Therefore, instead of opting for the more costly LAF system, a filter with a higher filtration rate would be a better choice for indoor environments that require higher air quality; this is valuable for operating room construction and maintenance budget allocation.

Effects of air-conditioning systems in the public areas of hospitals: A scoping review

Almost all hospitals are equipped with air-conditioning systems to provide a comfortable environment for patients and staff. However, the accumulation of dust and moisture within these systems increases the risk of transmission of microbes and have on occasion been associated with outbreaks of infection. Nevertheless, the impact of air-conditioning on the transmission of microorganisms leading to infection remains largely uncertain. We conducted a scoping review to screen systematically the evidence for such an association in the face of the coronavirus disease 2019 epidemic. PubMed, Embase and Web of Science databases were explored for relevant studies addressing microbial contamination of the air, their transmission and association with infectious diseases. The review process yielded 21 publications, 17 of which were cross-sectional studies, three were cohort studies and one case−control study. Our analysis showed that, compared with naturally ventilated areas, microbial loads were significantly lower in air-conditioned areas, but the incidence of infections increased if not properly managed. The use of high-efficiency particulate air (HEPA) filtration not only decreased transmission of airborne bioaerosols and various microorganisms, but also reduced the risk of infections. By contrast, contaminated air-conditioning systems in hospital rooms were associated with a higher risk of patient infection. Cleaning and maintenance of such systems to recommended standards should be performed regularly and where appropriate, the installation of HEPA filters can effectively mitigate microbial contamination in the public areas of hospitals.

Portable HEPA Purifiers to Eliminate Airborne SARS-CoV-2: A Systematic Review

OBJECTIVE

Current epidemiologic predictions of COVID-19 suggest that SARS-CoV-2 mitigation strategies must be implemented long-term. In-office aerosol-generating procedures pose a risk to staff and patients while necessitating examination room shutdown to allow aerosol decontamination by indwelling ventilation. This review summarizes the current state of knowledge on portable high-efficiency particulate air (HEPA) purifiers' effectiveness in eliminating airborne SARS-CoV-2 from indoor environments.

DATA SOURCES

Medline, Embase, Cochrane Databases, and the World Health Organization's COVID-19 Global Literature on Coronavirus Disease.

REVIEW METHODS

Data sources were systematically searched for original English-language published studies indexed up to January 14, 2021 per the following search strategy: ("HEPA" OR "High-efficiency" OR "High-efficiency particulate air" OR "Efficiency particulate" OR "Purifier" OR "Filter" OR "Cleaner" OR "Filtration") AND ("COVID" OR "COVID-19" OR "SARS-CoV-2" OR "Coronavirus"). Additional relevant studies were identified by searching the reference lists of included articles.

RESULTS

Eleven published studies have evaluated the effectiveness of portable HEPA purifiers in eliminating airborne SARS-CoV-2 with relevantly sized surrogate particles. Ten studies evaluated aerosols and submicron particles similar in size to SARS-CoV-2 virions. In all studies, portable HEPA purifiers were able to significantly reduce airborne SARS-CoV-2-surrogate particles. The addition of portable HEPA purifiers augmented other decontamination strategies such as ventilation.

CONCLUSION

Experimental studies provide evidence for portable HEPA purifiers' potential to eliminate airborne SARS-CoV-2 and augment primary decontamination strategies such as ventilation. Based on filtration rates, additional air exchanges provided by portable HEPA purifiers may be calculated and room shutdown times potentially reduced after aerosol-generating procedures.

A Qualitative Study on Concerns, Needs, and Expectations of Hospital Patients Related to Climate Change: Arguments for a Patient-Centered Adaptation

This study explores the concerns, needs, and expectations of inpatients with the goal to develop a patient-centered climate change adaptation agenda for hospitals. Statements of patients from geriatrics, internal medicine, psychiatry, and surgery (N = 25) of a German tertiary care hospital were analyzed using semi-structured interviews and the framework method. Areas of future adaptation were elaborated in joint discussions with transdisciplinary experts. Concerns included the foresight of severe health problems. The requested adaptations comprised the change to a patient-centered care, infrastructural improvements including air conditioning, and adjustments of the workflows. Guidelines for the behavior of patients and medical services appropriate for the climatic conditions were demanded. The patient-centered agenda for adaptation includes the steps of partnering with patients, reinforcing heat mitigation, better education for patients and medical staff, and adjusting work processes. This is the first study demonstrating that hospital patients are gravely concerned and expect adjustments according to climate change. Since heat is seen as a major risk by interviewees, the fast implementation of published recommendations is crucial. By synthesizing inpatients’ expectations with scientific recommendations, we encourage patient-centered climate change adaptation. This can be the start for further collaboration with patients to create climate change resilient hospitals.