Indoor Air Samples Research Articles

Comparative quantification of varicella-zoster virus in air, pharyngeal swabs, and vesicle content in patients with varicella, disseminated zoster, and localized herpes zoster.

We evaluated the viral load of varicella-zoster virus (VZV) in ambient air, vesicle, and pharyngeal swabs in VZV-infected patients. Of 46 cases, 6 had VZV detected in indoor air samples from patient rooms. Results suggest an association between viral load in the pharyngeal swab and indoor air.

Poultry farms as a One health priority for Aspergillus section Fumigati surveillance

Abstract In poultry production environments, particulate matter (PM) is considered one of the harmful air pollutants [2]. Considering potential biological pathogens, the genus Aspergillus in particular, Aspergillus fumigatus, is a widely recognized human and animal pathogen [3]. Hot-humid farm environments could contribute to the proliferation of these fungi [4]. Therefore, poultry production workers, besides animals [4], may be at a higher risk of inhaling fungi spores [4,5]. This study aimed to determine particulate matter (PM) contamination and analyze the prevalence of Aspergillus section Fumigati in air samples from poultry pavilions. Indoor and outdoor air samples were taken in the 1st, 2nd and 3rd weeks of birds growth cycle (n = 58). Air was collected through the impaction method (MAS-100) onto polycarbonate filters, set at 100 L/min, for 5 min. Followed by DNA extraction, and real-time PCR detection of Aspergillus section Fumigati. For PM evaluation, portable direct-reading equipment (Lighthouse, model 3016 IAQ) was used. Particle concentrations were measured (n = 67) at five distinct fractions during 5 min. Considering particles fractions, PM10 and PM5 where prevalent in 1st (58% PM10; 28% PM5), 2nd (63% PM10; 26% PM5) and 3rd (64% PM10; 25% PM5) weeks. These results evidence that coarse particles (between 2.5 and 10 µm) are the most relevant PM present in this setting. Regarding fungal detection, Aspergillus section Fumigati was widespread inside poultry pavilions (62%, 26 out of 42), highlighting this environment has a potential reservoir of microbial pathogens [7]. Furthermore, PM can act as a host of biological fragments [6]. Overall, in addition to molecular analysis, future studies should consider using culture-based methods to assess the viability of pathogenic microorganisms and their infection potential [3]. From a One Health perspective, quantitative and qualitative research is required to fully understand this environment. Key messages • This study evidence that coarse particles (between 2.5 and 10 µm) are the most relevant PM present and Aspergillus section Fumigati is widespread in poultry pavilions. • A One health intervention should be considered in future studies.

Detection of airborne wild waterbird-derived DNA demonstrates potential for transmission of avian influenza virus via air inlets into poultry houses, the Netherlands, 2021 to 2022.

BackgroundOutbreaks of highly pathogenic avian influenza (HPAI) on poultry farms and in wild birds worldwide persists despite intensified control measures. It causes unprecedented mortality in bird populations and is increasingly affecting mammalian species. Better understanding of HPAI introduction pathways into farms are needed for targeted disease prevention and control. The relevance of airborne transmission has been suggested but research involving air sampling is limited and unequivocal evidence on transmission routes is lacking.AimWe aimed to investigate whether HPAI virus from wild birds can enter poultry houses through air inlets by characterising host materials through eukaryote DNA sequencing.MethodsWe collected particulate matter samples in and around three HPAI-affected poultry farms which were cleared and decontaminated before sampling. Indoor measurements (n = 61) were taken directly in the airflow entering through air inlets, while outdoor air samples (n = 60) were collected around the poultry house. Positive controls were obtained from a bird rehabilitation shelter. We performed metabarcoding on environmental DNA by deep sequencing 18S rRNA gene amplicons.ResultsWe detected waterbird DNA in air inside all three, and outside of two, poultry farms. Sequences annotated at species level included swans and tufted ducks. Waterbird DNA was present in all indoor and outdoor air samples from the bird shelter.ConclusionAirborne matter derived from contaminated wild birds can potentially introduce HPAI virus to poultry houses through air inlets. The eDNA metabarcoding could assess breaches in biosecurity for HPAI virus and other pathogens potentially transmitted through air via detection of their hosts.

Identification of respiratory virus in indoor air of hospitals: A comparison of adult and children's hospital

Air sampling was done inside adult and children's hospitals that were selected to treat severe cases of COVID-19. Influence of peripheral factors such as particle concentration, air velocity, sampling point dimensions, distance from the patient bed, sampling time, the flow rate of sampling pump, and factors related to COVID-19 patients (disease period, mask use, number, and age) were analyzed using multivariate analysis (RT-PCR). The results showed that 5.8% (N = 8) of indoor air samples were positive for the presence of the coronavirus. The presence of viruses in the indoor air of hospitals has a strong positive relationship with particles and the age of patients while it has a reverse relationship with the air cleaner, ventilation system, and distance from the patients. Therefore, the higher particle concentration, the age of hospitalized patients, and the remarkable number of patients increase the probability of the presence and identification of the coronavirus in the indoor air of hospital wards. Also, the presence of an air cleaner, a suitable ventilation system especially a mechanical one, and increasing the distance from the patients reduces the possibility of virus existence in the indoor air and its identification. In general, the results showed that the adult hospital has more polluted indoor air than the children's hospital in terms of the presence of SARS-COV-2. Sanitation and engineering measures like upgrading the ventilation system, particularly in vulnerable wards of hospitals are recommended.

Clearing the Air, Breathe Easy: Intensive Care Unit Remodeling Unveils Insights into Aspergillosis Prevention

Background: Invasive aspergillosis (IA) poses a substantial threat to morbidity and mortality, particularly among immunocompromised individuals. In 2023, a New York City Intensive Care Unit (ICU) experienced an aspergillus outbreak following a structural water leak, resulting in two patients diagnosed with Invasive Aspergillus niger in their bronchial cultures. Immediate interventions, including patient relocation and ICU reconstruction were implemented to mitigate further impacts. This study aims to assess the impact of timely relocation of patients and renovation of the ICU, on the incidence of invasive aspergillosis. Method: A quasi-experimental study design of ICU patients over a nine month period included surveillance by the Infection Prevention department from March 1 to December 1, 2023. Surveillance included review of microbiology reports, environmental cultures, and patient chart reviews. The Pre-intervention spanned March 1 to May 1, and the post-intervention from May 4 to December 1. Indoor mold assessments of pre- and post-intervention involved testing wall surfaces for moisture, air sample collection for fungal spores, and surface swabs for direct fungal analysis. The intervention included relocating all seventeen patients from the impacted ICU and comprehensive reconstruction. Reconstruction involved the removal and replacement of all sheetrock within the unit extending four feet from the floor with moisture-resistant sheetrock. Additionally, moisture resistant single sheet welded vinyl flooring and cove-bases were installed. All heating, ventilation, and air-conditioning (HVAC) systems were inspected and cleaned. Construction activities strictly adhered to Infection Control Risk Assessment (ICRA) guidelines, with emphasis on maintaining negative pressure, to ensure a safe environment. Result: Environmental swab samples from 50% of ICU rooms indicated growth of Aspergillus/Penicillium, Chaetomium, and Stachybotrys/Memnoniella type spores during the pre-intervention phase. Environmental microbiology results strongly suggest the indoor environment as the fungal spore source, with the presence of fruiting structures indicating surface mold growth. Indoor air samples, when compared to outdoor samples collected during pre-intervention, showed rare (2-6 raw count) growth of Aspergillus in 55% of the sampled rooms and subequently no growth post-intervention. Prospective surveillance revealed no further aspergillus growth in the ICU population and environment. Conclusion: Our findings highlight a potential correlation between environmental modifications and reduced IA incidence. Swift mitigation and structural interventions are crucial in averting potentially fatal outcomes, marking a significant advancement of prevention strategies for inner-city hospital settings. Although promising, study limitations include the inability to speciate environmental aspergillus for comparison to patient bronchial cultures and the absence of baseline bronchial cultures for affected patients on admission.

Exposure assessment of metal(loids) in indoor air and biomonitoring in six urban residential areas in Iran

Exposure to metal(loid)s can cause adverse health effects. This study evaluated the concentrations of aluminum, arsenic, cadmium, chromium, mercury, nickel, and lead in particulate matter <10 μm (PM10) and in the urine of 100 participants from urban residential areas in Iran. A total of 100 residential buildings (one adult from each household) in six cities across Iran were recruited for this study. The levels of metal(loid)s in PM10 and the urine of participants were measured using acid digestion followed by inductively coupled plasma mass spectrometry (ICP-MS). The average (±SE) PM10 concentration in the buildings was 51.7 ± 3.46 μg/m3. Aluminum and cadmium had the highest and lowest concentrations among the metal(loid)s, averaging 3.74 ± 1.26 μg/m3 and 0.01 ± 0.001 μg/m3, respectively. In 85 % of the samples, the concentration of metal(loid)s in indoor air exceeded WHO air quality standards. Cadmium and lead had the highest and lowest numbers of indoor air samples exceeding the recommended standards, respectively. A significant correlation was found between the concentration of metal(loid)s in urine samples and indoor PM10 levels, as well as the wealth index of participants. There was also a significant direct relationship between the concentrations of nickel, arsenic, lead, and mercury in urine and the age of participants. Factors such as building location, type of cooling systems, use of printers at home, and natural ventilation influenced the concentration and types of metal(loid)s in the indoor air.

Fragrance chemicals in nail salons: Personal inhalation exposures and potential sources

The indoor air of nail salons is full of volatile organic compounds (VOCs), many of which have fragrances. Little is known about the fragrance chemicals in nail salons, as fragrance ingredients are not required on nail product labels and are considered trade secrets. This study aimed to identify fragrance chemicals and their potential sources and exposures in nail salons. Indoor air samples were collected in seven nail salons in the Greater Boston Area between November 2016 and June 2017. Personal samples were also collected from ten nail salon workers during their work shifts. Follow-up area sampling was performed in two salons one year after the initial visits. All air samples were collected using thermal desorption (TD) tubes and analyzed on a TD-gas chromatography/mass spectrometry (GC/MS) system targeting 55 fragrance chemicals. Eighteen compounds were detected in air samples, including terpenes, alcohols, carbonyls, ethers, and esters. The concentrations displayed limited spatial variation within a salon but moderate variation over time. The highest median personal inhalation concentrations were benzaldehyde (36.4 μg/m3), 2-ethylhexanol (30.0 μg/m3), d-limonene (16.6 μg/m3), and 2-butoxyethanol (12.6 μg/m3). Highest personal levels were reached by maximum concentrations of 2-butoxyethanol (<1611 μg/m3)), d-limonene (<413 μg/m3), and methyl salicylate (<113.5 μg/m3). Personal concentrations of most compounds were highly correlated with area concentrations (Spearman correlations = 0.69−0.92). Fragrance concentrations from area and personal air samples did not correlate significantly with the ventilation rate. Cleaning agents, personal care products, and nail products were identified as important possible emission sources. This study reveals a subset of fragrance chemicals in nail salons’ indoor air and calls for future research on a full spectrum of these chemicals, their health effects among nail salon workers, and ways to reduce these exposures.

Nontarget Identification of Novel Organophosphorus Flame Retardants and Plasticizers in Indoor Air and Dust from Multiple Microenvironments in China.

The indoor environment is a typical source for organophosphorus flame retardants and plasticizers (OPFRs), yet the source characteristics of OPFRs in different microenvironments remain less clear. This study collected 109 indoor air samples and 34 paired indoor dust samples from 4 typical microenvironments within a university in Tianjin, China, including the dormitory, office, library, and information center. 29 target OPFRs were analyzed, and novel organophosphorus compounds (NOPs) were identified by fragment-based nontarget analysis. Target OPFRs exhibited the highest air and dust concentrations of 46.2-234 ng/m3 and 20.4-76.0 μg/g, respectively, in the information center, where chlorinated OPFRs were dominant. Triphenyl phosphate (TPHP) was the primary OPFR in office air, while tris(2-chloroethyl) phosphate dominated in the dust. TPHP was predominant in the library. Triethyl phosphate (TEP) was ubiquitous in the dormitory, and tris(2-butoxyethyl) phosphate was particularly high in the dust. 9 of 25 NOPs were identified for the first time, mainly from the information center and office, such as bis(chloropropyl) 2,3-dichloropropyl phosphate. Diphenyl phosphinic acid, two hydroxylated and methylated metabolites of tris(2,4-ditert-butylphenyl) phosphite (AO168), and a dimer phosphate were newly reported in the indoor environment. NOPs were widely associated with target OPFRs, and their human exposure risk and environmental behaviors warrant further study.

Concomitant determination of PAH, PCBs, and phthalates in indoor air and dust from residential houses in the Strasbourg region of France

Global attention is drawn to the significant issue of indoor pollution, given its direct negative impact on human health and wellness. Typically, individuals can nowadays spend 80% or more of their time in enclosed built locations where they can be prone to a multitude of harmful toxic chemicals distributed in particulate and gas phases. Therefore, a systematic efficient monitoring of such chemicals in indoor environments is urgently required to devise and implement various measures that allow their control. The objective of this study is to evaluate the concomitance occurrence of phthalates, polycyclic aromatic hydrocarbons (PAHs), and polychlorinated biphenyls (PCBs) within the indoor settings of residential homes in Strasbourg. It focused on both the indoor air and dust samples collected in nine residential homes in Strasbourg for a one-year sampling period, February 2016 - February 2017. For this, Radiello®, SiC© foams, and Tenax-TA® were successfully introduced and used as reliable passive samplers for the aforementioned matrices. Extractions were carried out using pressurized solvent extraction (PSE) followed by ATD-GC/MSMS analysis. The findings of the presented study revealed that 12 PAHs, 18 PCBs, and 7 phthalates were regularly perceived in the indoor environments of the houses under assessment. In gaseous samples, the average concentrations of the detected pollutant were approximately 3,919, 4.3, and 601.6 ng/sampler for PAHs, PCBs, and phthalates, respectively. As for dust samples, the average concentrations of the detected pollutant were approximately 3,438, 6.2, and 1,816.2 ng/g, respectively. The obtained results showed that PCBs exhibited the lowest concentration in both matrices. However, air samples were mostly contaminated by PAHs, while dust samples showed higher levels of phthalates. These results are correlated to the physico-chemical properties of these compounds and to their origin and source of emission. The findings of this study stress the importance of indoor pollution assessment so that the risks associated with it could be controlled.

Pyr-GC-Orbitrap-MS method for the target/untargeted analysis of microplastics in air

Pyrolysis-gas chromatography coupled to Orbitrap-mass spectrometry is a novel technique that allows the low level and precise determination of microplastics in environmental samples. In this paper, we develop and assess the target and untargeted performance of Pyr-GC-Orbitrap-MS. The method was optimized for 10 plastic polymers: polymethyl methacrylate, nylon-6,6, polypropylene, nitrile butadiene rubber, polyvinyl chloride, polyethylene terephthalate, acrylonitrile butadiene styrene, polyethylene, polycarbonate, and polystyrene. Standards were home-made using a diamond driller to attain mean sizes within the range of 45–382 µm. A step-by-step optimization of the analytical procedure was carried out. First, accurate mass measurement of each polymer at 60,000 resolution was studied to select the 3 most intense and selective quantification and confirmation ions. Second, internal standard quantification was optimized, and good linearity, repeatability, and reproducibility were obtained. Blank contribution and instrumental detection limit were evaluated for each polymer. Finally, the combined and expanded uncertainty of the Pyr-GC-Orbitrap-MS method was calculated to determine the sources of variation, considering that home-made standards were used. To evaluate method performance, targeted and non-targeted analysis of indoor air samples collected from gyms and department stores were carried out. The Pyr-GC-Orbitrap-MS methodology herein described can be applied for the quantitative assessment of MPs and other substances in different matrices.

Indoor plants regulate the respiratory bacteria of high-altitude migrants and improve their environmental adaptability

Migrants traveling from plains to Ngari Prefecture, Tibet, China, with an average altitude of over 4500 m, may suffer serious respiratory function deterioration. Regulating the respiratory microbiome by altering residence indoor air microbiome is a potential approach to improve their respiratory health. To investigate the impact of indoor plants on the respiratory bacteria of high-altitude migrants and its effects on respiratory system health, based on 16S rRNA gene sequencing of 56 respiratory samples and 56 indoor air samples from the participants in Ngari, this study analyzed the effects of indoor plants on the respiratory bacteria of Ngari migrants, compared the effects of indoor plants on migrants and local Tibetans, and analyzed the association between plant-related respiratory bacteria changes and health protection. Migrants with different numbers of indoor plants exhibited significant difference in respiratory bacteria β diversity. Compared to migrants with fewer plants, migrants with more plants had an approximately 23% lower cumulative relative abundance of pathogenic genera in their respiratory dominant genera, and had 10 unique indoor air-respiratory shared core OTUs, some of which belong to plant-related genera. Migrants with different numbers of indoor plants showed greater differences in respiratory bacteria diversity and specific taxa compared to local Tibetans. Migrants with more indoor plants possessed individual unique indoor air-respiratory shared core OTUs that were significantly positively correlated with inspiratory reserve volume or expiratory reserve volume. Overall, indoor plants alter the diversity and composition of migrants' respiratory bacteria, and the changes in composition positively impact on respiratory health and high-altitude adaptability.

Evaluation of Effectiveness of Following Standard Operating Procedures in the Department of Forensic Medical Examination Based on Bacteriological Test Results

Introduction: The activities of forensic medical examiners are associated with an increased risk of contracting highly infectious diseases. Introduction of standard operating procedures into the daily practice of these health professionals can increase their biological safety. Objective: To evaluate effectiveness of implementing standard operating procedures (SOPs) in order to improve biological safety of the personnel performing autopsies in the Republican Bureau of Forensic Medicine in the city of Kazan. Materials and methods: The results of bacteriological testing of 120 indoor air samples for the total plate count, Staphylococcus aureus, yeast, and mold counts, and 320 surface wipe samples for S. aureus and total coliform counts, collected from February 3, 2021 to June 18, 2021 in the Autopsy Division before and after enforcement of standard operating procedures, were analyzed using the Student’s t-test, Mann-Whitney U test, and McNemar test. Results: The analysis of 40 air samples taken after SOP enforcement and tested for the total plate count showed a significant decrease in bacteriological contamination of the premises: from 1,000.0 to 226.7 CFU/m3 (T = 5.7, p &lt; 0.01) and from 812.5 to 165.0 CFU/m3 (T = 6.287, p &lt; 0.001) in the Teaching Autopsy Room and Autopsy Room One, respectively. A statistical decrease was also observed in airborne fungal concentrations in Autopsy Room One (T = 3.727, p &lt; 0.01) and the Teaching Autopsy Room (T = 5.129, p &lt; 0.01). The post-SOP frequency of detection of coliform bacteria on various surfaces and autopsy instruments demonstrated a significant reduction as well (160 wipe samples, p &lt; 0.001). Conclusion: The study results show a pronounced decrease in microbial contamination of the Autopsy Division following introduction of standard operating procedures into the activities of the Republican Bureau of Forensic Medicine in the city of Kazan. It can be argued that standard operating procedures are effective in ensuring biological safety of healthcare workers.

Pollution characteristics and health risk assessment of fine particulate matter and its metal elements during Chinese New Year

The Chinese Lunar New Year is a significant festival in China that leads to indoor and outdoor air pollution with distinct characteristics compared to normal times. In this study, indoor and outdoor air samples were collected and analysed to investigate the indoor and outdoor pollution of PM2.5 and its metal elements during the Chinese New Year. The findings reveal that there is a notable positive correlation between indoor and outdoor PM2.5 concentrations during the Chinese New Year, with outdoor concentrations being higher on average. The levels of PM2.5 concentrations indoors and outdoors started to increase on Chinese New Year’s Eve and peaked after the early hours of the Chinese New Year. The total concentrations of six metal elements (Cd, Cr, Ni, Cu, Pb and Zn) in indoor and outdoor PM2.5 during the Chinese New Year in 2022 were 738.73 ± 134.93 mg/kg and 1124.38 ± 553.14 mg/kg, respectively. Principal component analysis suggests that the main sources of indoor metal elements were from outdoor combustion sources and human activities, while outdoor sources were fireworks displays and emissions from coal combustion. Based on the U.S. EPA risk assessment carried out, both indoor and outdoor PM2.5 metal elements could pose a carcinogenic risk to adults.

Altitude-associated trends in bacterial communities in ultrahigh-altitude residences

BackgroundIndoor bacterial communities may change with altitude because their major contributors, outdoor bacterial communities, vary with altitude. People’s health effects from bacteria inhalation exposure can also vary with altitude because human respiratory physiology changes with oxygen content in air. Accordingly, adjusting indoor bacterial communities may help to acclimate newcomers from low-altitude environments to ultrahigh-altitude environments. To lay the groundwork for further research, we aimed to first elucidate the bacterial communities in ultrahigh-altitude residences and the effects of altitude on these communities. We collected 187 environmental samples from residential communities at ultrahigh altitudes of 3811–4651 m in Ngari, China and sequenced bacterial 16S rRNA genes. ResultsOn one hand, when abundant genera in ultrahigh-altitude residences and those reported by previous studies on low-altitude residences were compared, nine genera were shared, whereas other five genera were abundant only at ultrahigh altitudes. On the other hand, when the bacterial communities of residences at different ultrahigh altitudes were further compared, the bacterial composition in indoor surface samples varied significantly with altitude. The relative abundance of five bacterial genera in indoor air samples and 10 genera and three phyla in indoor surface samples varied monotonically with altitude. ConclusionsAltitude may be a long-neglected factor that shapes residential bacterial communities and thus warrants attention.

Characterization of microplastics in outdoor and indoor air in Ranchi, Jharkhand, India: First insights from the region

The study focused on detecting and characterizing microplastics in outdoor and indoor air in Ranchi, Jharkhand, India during post-monsoon (2022) and winter (2023). Stereo microscopic analysis showed that plastic fibres had a dominant presence, fragments were less abundant, whereas fewer films could be detected in indoor and outdoor air. The atmospheric deposition of microplastics outdoors observed 465 ± 27 particles/m2/day in PM10 and 12104 ± 665 and 13833 ± 1152 particles/m2/day in PM2.5 in quartz and PTFE, respectively during the post-monsoon months. During winter, microplastic deposition rates in PM10 samples were found to be 689 ± 52 particles/m2/day and 19789 ± 2957 and 30087 ± 13402 in quartz and PTFE particles/m2/day respectively in PM2.5. The mean deposition rate in indoor environment during post-monsoon was 8.3 × 104 and 1.03 × 105 particles/m2/day in winter. During the post-monsoon period in PM10, there were fibres from 7.7 to 40 μm and fragments from 2.3 μm to 8.6 μm. Indoor atmospheric microplastics, fibres ranged from 1.2 to 47 μm and fragments from 0.9 to 16 μm present respectively during the post-monsoon season. Fibres and fragment sizes witnessed during winter were 3.6–6.9 μm and 2.3–34 μm, respectively. Indoor air films measured in the range of 4.1–9.6 μm. Fourier transform infrared analysis showed that outdoor air contained polyethylene, polypropylene, Polystyrene, whereas indoor air had polyvinyl chloride. Polyethylene mainly was present in outdoor air, with lesser polypropylene and polystyrene than indoors, where polyvinyl chloride and polyethylene were in dominant proportions. Elemental mapping of outdoor and indoor air samples showed the presence of elements on the microplastics. The HYSPLIT models suggest that the particles predominantly were coming from North-West during the post-monsoon season. Principal component analysis indicated wind speed and direction influencing the abundance of microplastics. Microplastics concentration showed strong seasonal influence and potential to act as reservoir of contaminants.

Investigating Microbial Contamination of Indoor Air, Environmental Surfaces, and Medical Equipment in a Southwestern Ethiopia Hospital.

Healthcare-associated infections, primarily caused by microorganisms, are widespread in healthcare facilities. These infections pose a significant challenge, especially in low and middle-income countries, and have a detrimental impact on patient outcomes. It is crucial to assess the level of microbial load and associated factors to prevent the spread of these infections. The objective of this study was to assess the microbial load and identify the factors associated with it in various wards at Jimma Medical Center. A cross-sectional study conducted at Jimma Medical Center. Indoor air samples were collected using the settle plate method with a 1/1/1 scheme. Inanimate surfaces and medical equipment were sampled using Swabs from a 10 × 10 cm area. A total of 268 samples were collected from 10 rooms. Pertinent information regarding the associated factors was gathered using an observational checklist. A multiple linear regression model was used to identify any associations with the microbial load. Out of the total samples, 181 (67.5%) tested positive for culture, and 270 microbes were isolated. The average load of bacteria and fungi in the indoor air ranged from 124.4 to 1607 and 96 to 814.6 Colony-forming unit (CFU)/m3, respectively. The mean total aerobic colony counts of bacteria and fungi from all surfaces in the wards ranged from 5.25 to 43.3 CFU/cm2. Crowdedness [β = 2.748 (95% Confidence Interval (CI): 1.057-4.44)], the presence of waste material [β = 1.747 (95% CI: 0.213-3.282)], and an unclean room [β = 2.505 (95% CI: 0.990-4.019)] were significantly associated with the microbial load. The microbial load detected in indoor air, inanimate surfaces and medical equipment was posing potential health risks. Consequently, it is recommended to implement regular microbial surveillance of the hospital environment and enhance the infection prevention program to mitigate these concerns.

Centralised Air Sampling From a Ventilation System for the Surveillance of Respiratory Pathogens

Background: The COVID‐19 pandemic has triggered a renewed interest in indoor air sampling for infectious disease surveillance. However, scalability is currently limited, as samples are usually collected in a single indoor space. An alternative is to place the device within a heating, ventilation, and air conditioning system (HVAC), but this approach has not been tested against room air sampling.Methods: In this observational study, we sampled the air in an indoor fitness centre for 2 or 6 h, simultaneously in three locations of the main exercise hall and in the return plenum of the HVAC system. Samples were collected twice weekly for 11 weeks. All samples were tested for 29 respiratory pathogens using PCR. We compared the ventilation system and exercise hall air with regard to the presence and quantity of pathogens.Findings: Samples collected in two locations in the exercise hall had a similar overall sensitivity to the HVAC sampler for detecting pathogens, while a third sampling location was associated with significantly lower sensitivity. Overall, the pathogen concentration was similar in the ventilation system and the exercise hall air (ratio: 1.0; 95% CI: 0.8–1.3).Interpretation: Our results show that air sampling within a ventilation system can have equal sensitivity for detecting respiratory pathogens, compared to room‐based sampling. Thus, placing samplers within central ventilation systems could increase the scalability of air sampling for infectious disease surveillance.

Indoor Air Sampling for Detection of Viral Nucleic Acids

Indoor Air Sampling for Detection of Viral Nucleic Acids

Characteristics of Airborne Particles and Bacteria in Hospital Indoor and Outdoor Air

Introduction: Given that hospital air is one of the important environmental sources for transmission of microorganisms, the importance of airborne transmission in the epidemiology of hospital-acquired infections (HAIs) has gained attention in the past two decades. Therefore, the present study aims to determine the concentration of bacteria in association with airborne particulate matter (PM) in the outdoor and indoor air of two hospital wards. Materials and methods: The GRIMM 1.109 dust monitor and the Andersen one-stage viable impactor were used for particle counting and bioaerosol sampling, respectively. Results: The average levels of airborne bacteria sampled from outdoor air were 33 colony-forming units (CFU/m3), and in the air samples of medical and infectious disease wards, they were 76 and 85 CFU/m3, respectively. Staphylococcus spp. and Acinetobacter spp. were the most prevalent bacteria in the samples. Statistical analysis showed a significant association between PM2.5, and PM10 particle mass concentrations and airborne bacteria concentrations in indoor air samples (P-value &lt; 0.05). Conclusion: Some bacterial agents of HAIs existed in hospital air and may be problematic for immunocompromised patients. Higher levels of bacteria in indoor air compared to outdoor air may indicate that the bacteria were of indoor origin, such as the presence and activities of people. Moreover, the results showed that particle counting may be a useful tool for airborne bacteria monitoring.

Effect of Polycyclic Aromatic Hydrocarbons Extracted from Indoor Air of Coffee Shops on Oral Squamous Carcinoma Cell (KB/C152): An in Vitro Approach

Introduction: The two main causes of indoor air pollution (IAP) are cooking and smoking. Toxic substances, including polycyclic aromatic hydrocarbons (PAHs), recognized as human carcinogens, are present in cooking and tobacco smoke. This study aims to determine the cytotoxicity and genotoxicity of PAHs collected from the indoor air of coffee shops on human cell line (KB/C152) in vitro approach.&#x0D; Materials and methods: Sampling pumps at a 2 l/min flow rate for 5 hours were applied to collect indoor air samples. Next, KB cells in cell culture medium were exposed to different concentrations of extracted PAHs using Methyl Thiazolyl Tetrazolium (MTT) test. Finally, terminal dUTP nick-end labeling (TUNEL) test and cell cycle assessments were both examined using flow cytometry.&#x0D; Results: The MTT test revealed a significant cytotoxic effect on KB cells depending on the PAHs concentrationas compared to the control cell line. The lethal concentration 50 (LC50) value against KB cells was 100 ± 3.09 µg/ml. Accordingly, exposure to extracted PAHs resulted in an arrest in the cell cycle at the sub-G1 checkpoint. The extracted PAHs suppressed the cell cycle in the sub-G1 phase, damaged DNA, and arrested KB cells from proliferating. Additionally, a statistically significant increase in DNA cleavage percentages (p ≤ 0.05) was seen in the TUNEL test, which also showed a dose-dependent increase in DNA damage.&#x0D; Conclusion: Extracted PAHs caused DNA damage and arrested in the cell cycle in epidermoid carcinoma of the mouth cells (KB/C152) in vitro mechanisms. This evaluation highlights mechanisms of exposure to extracted PAHs and their detrimental health effects.