Indoor Air Samples Research Articles

Evaluation of VOCs from fungal strains, building insulation materials and indoor air by solid phase microextraction arrow, thermal desorption–gas chromatography-mass spectrometry and machine learning approaches

Solid phase microextraction Arrow and thermal desorption–gas chromatography–mass spectrometry allowed the collection and evaluation of volatile organic compounds (VOCs) emitted by fungal cultures from building insulation materials and in indoor air. Principal component analysis, linear discriminant analysis and supported vector machine were used for visualization and statistical assessment of differences between samples. In addition, a screening tool based on the soft independent modelling of class analogies (SIMCA) was developed for identification of fungal contamination of indoor air. Ten different fungal strains, incubated under ambient and microaerophilic conditions, were analyzed for time period ranging from 5 to 29 days after inoculation resulting in a total of 140 samples. In addition, the effect of additives on the fungal growing media was studied. The total number of compounds and concentration values were used for the evaluation of the results. Clear differences were observed for VOC profiles emitted by different fungal strains by exploiting long chain alcohols (3-octanol, 1-hexanol and 2-octen-1-ol) and sesquiterpenes (farnesene, cuprene). The analysis of glass-wool and cellulose based building insulation materials (3 samples) gave clear differences, mainly for oxygenated compounds (ethyl acetate and hexanal) and benzenoids (benzaldehyde). Moreover, the comparison of indoor air and insulation materials collected from a house with fungal indoor air problems indicated that 42% of the VOCs were found in both samples. The analysis of 52 indoor air samples demonstrated clear differences in their VOC profiles, especially for hydrocarbons, and between control (44 samples) and indoor air problem houses (8 samples). Finally, the SIMCA model enabled to recognize differences between control and fungi contaminated houses with a prediction capacity over 84%.

Airflow Distribution of Hall and Classroom as Temporary Evacuation Centers: A Case Study in Melaka

During floods, the Malaysian Department of Welfare (JKM) oversees the opening and assigning of victims to evacuation centres. Public buildings such as school classrooms and community halls act as Temporary Evacuation Centers (TEC) that can last up to two weeks. The foldable tents will be provided to each family at the evacuation centres to assure that the victims have personal space. For privacy and separation, they were confined in a temporary tent with only a few fans from the building to keep their comfort. Therefore, the thermal comfort level within the temporary tent is usually affected by the airflow distribution from naturally ventilated buildings from building layout and design. In this study, two independent public buildings were hall (School A) and a classroom (School B) in Melaka, Malaysia, were investigated to simulate the airflow distribution accordingly. In-situ air sampling measures were performed using indoor air sampling techniques for 24 hours to measure the air velocity, air temperatures, and relative humidity in the building. Airflow distribution throughout the floor was used to simulate the airflow with the Computer Fluid Dynamics (CFD) model to identify the airflow direction. The average airflow rate between Schools A and B was 0.19 ms-1 and 0.27 ms-1, respectively, after the data collection. Meanwhile, the average air temperature between Schools A and B was 30.3℃ and 29.4℃, respectively. Therefore, School B's classroom layout is the best model for forecasting airflow rate, air velocity, and temperature for the evacuation center.

Mathematical modeling of ammonia emission rate in newly constructed buildings

A rapid growth in monolithic residential construction over recent decades has created a problem associated with ammonia contamination inside newly constructed buildings. Absence of substantiated preventive actions aimed at minimizing ammonia emissions hinders commissioning of new residential buildings and may create an unfavorable sanitary-epidemiological situation with obvious olfactory-reflex and irritating effects on public health. The aim of this study was to develop a scientifically grounded method to predict when ammonia concentrations emitted from concrete constructions would reach their permissible levels in air inside contaminated premises in newly constructed buildings. Ammonia emissions were estimated based on data of laboratory tests that involved analyzing indoor air samples taken in Saint Petersburg and the Leningrad region. Indoor air was analyzed in 4 newly constructed residential buildings (165 premises, 57 test protocols, 893 air samples tested to identify ammonia in them). Relationships between changes in ammonia concentrations and ventilation time were obtained by using regression analysis (regression equation, least square method). To establish reproducibility of the results and a possibility to compare them, we tested variances for homogeneity by using Fisher criterion. Sampled populations were compared with Student’s t-test in case the data fitted to a normal distribution (Kolmogorov – Smirnov test, Shapiro – Wilks test). Critical significance was taken at 0.05 in all the statistical comparisons. We have developed a method for predicting when ammonia concentrations that occurred in indoor air inside newly constructed buildings due to multi-day emissions from building materials would reach their permissible levels. The method involves multi-day measurements (y, mg/m3) of ammonia concentrations sequentially in each premise inside a newly constructed building on any day of measurements during the time period t; building up relationships between averaged ammonia concentrations (yav, mg/m3) and a time moment t; mathematical analysis of the obtained relationships by parameterization and statistical analysis of the obtained kinetic parameters.

Математическое моделирование скорости эмиссии аммиака во вновь выстроенных зданиях

A rapid growth in monolithic residential construction over recent decades has created a problem associated with ammonia contamination inside newly constructed buildings. Absence of substantiated preventive actions aimed at minimizing ammonia emissions hinders commissioning of new residential buildings and may create an unfavorable sanitary-epidemiological situation with obvious olfactory-reflex and irritating effects on public health. The aim of this study was to develop a scientifically grounded method to predict when ammonia concentrations emitted from concrete constructions would reach their permissible levels in air inside contaminated premises in newly constructed buildings. Ammonia emissions were estimated based on data of laboratory tests that involved analyzing indoor air samples taken in Saint Petersburg and the Leningrad region. Indoor air was analyzed in 4 newly constructed residential buildings (165 premises, 57 test protocols, 893 air samples tested to identify ammonia in them). Relationships between changes in ammonia concentrations and ventilation time were obtained by using regression analysis (regression equation, least square method). To establish reproducibility of the results and a possibility to compare them, we tested variances for homogeneity by using Fisher criterion. Sampled populations were compared with Student’s t-test in case the data fitted to a normal distribution (Kolmogorov – Smirnov test, Shapiro – Wilks test). Critical significance was taken at 0.05 in all the statistical comparisons. We have developed a method for predicting when ammonia concentrations that occurred in indoor air inside newly constructed buildings due to multi-day emissions from building materials would reach their permissible levels. The method involves multi-day measurements (y, mg/m3) of ammonia concentrations sequentially in each premise inside a newly constructed building on any day of measurements during the time period t; building up relationships between averaged ammonia concentrations (yav, mg/m3) and a time moment t; mathematical analysis of the obtained relationships by parameterization and statistical analysis of the obtained kinetic parameters.

Microplastics in the surgical environment

Atmospheric microplastics (MPs) have been consistently detected within indoor and outdoor air samples. Locations with high human activity are reported to have high MP levels. The aim was to quantify and characterise the MPs present within the surgical environment over a one-week sampling period. MPs were collected in samplers placed around an operating theatre and adjoining anaesthetic room at 12 h intervals. Particles were filtered onto 0.02 µm membranes and analysed using micro-Fourier-transform infrared spectroscopy. The number of MPs identified during the working day sampling period varied, with a mean of 1,924 ± 3,105 MP m−2 day−1 and a range of 0 – 9,258 MP m−2 day−1 observed in the theatre, compared with a mean of 541 ± 969 MP m−2 day−1 and a range of 0 – 3,368 MP m−2 day−1 for the anaesthetic room. Across both rooms and at all sampling points, an increase in levels with a decrease in MP size was observed. Identified particles consisted of mainly fragment shaped MPs (78 %) with polyethylene terephthalate (37 %), polypropylene (25 %), polyethylene (7 %) and nylon (13 %) representing the most abundant polymer types. MPs were not detected in the theatre during non-working hours. The results provide novel information on defining polymer levels and types, in a room environment where the use of single plastics has been regarded as beneficial to practice. These results can inform cellular toxicity studies, investigating the consequences of human MP exposure as well as represent a potentially novel route of exposure for humans for this emerging contaminant of concern, via surgery.

Impact of Exposure to Indoor Air Chemicals on Health and the Progression of Building-Related Symptoms: A Case Report

The aetiology of building-related symptoms (BRSs) is not well supported by sufficient scientific evidence, and it remains unclear whether BRSs are mediated by psychosocial and personal factors or a genuine physical susceptibility to low-dose chemical exposure. In April 2014, a 40-year-old man consulted the Environmental Medical Clinic at Chiba University complaining of recurring BRSs. Indoor air samples were collected from the patient’s house at 11 time points and subjected to chemical analyses. The patient simultaneously completed a questionnaire about his symptoms at the time of the measurements. Statistical examination of the indoor environmental factors and patient survey revealed that the patient’s symptoms were highly correlated with the indoor air quality. Additionally, ventilation may have mitigated his BRSs, whereas aerial odour did not trigger symptoms. These findings suggest that exposure to specific airborne chemicals in an indoor environment can cause BRSs, and ventilation may be one of the treatment options to mitigate symptoms. Additional investigations on the adverse impacts of airborne environmental chemicals on human health are necessary to develop effective treatments and establish preventive measures for BRSs, and further improvement of ventilation systems is required to ensure clean indoor air.

Shower water contributes viable nontuberculous mycobacteria to indoor air.

Nontuberculous mycobacteria (NTM) are frequently present in municipal drinking water and building plumbing, and some are believed to cause respiratory tract infections through inhalation of NTM-containing aerosols generated during showering. However, the present understanding of NTM transfer from water to air is insufficient to develop NTM risk mitigation strategies. This study aimed to characterize the contribution of shower water to the abundance of viable NTM in indoor air. Shower water and indoor air samples were collected, and 16S rRNA and rpoB genes were sequenced. The sequencing results showed that running the shower impacted the bacterial community structure and NTM species composition in indoor air by transferring certain bacteria from water to air. A mass balance model combined with NTM quantification results revealed that on average 1/132 and 1/254 of NTM cells in water were transferred to air during 1 hour of showering using a rain and massage showerhead, respectively. A large fraction of the bacteria transferred from water to air were membrane-damaged, i.e. they had compromised membranes based on analysis by live/dead staining and flow cytometry. However, the damaged NTM in air were recoverable as shown by growth in a culture medium mimicking the respiratory secretions of people with cystic fibrosis, implying a potential infection risk by NTM introduced to indoor air during shower running. Among the recovered NTM, Mycobacterium mucogenicum was the dominant species as determined by rpoB gene sequencing. Overall, this study lays the groundwork for future pathogen risk management and public health protection in the built environment.

ASSOCIATION BETWEEN RESPIRATORY COMPLAINTS AND PM 10 CONCENTRATION IN HOUSEHOLDS IN PALEMBANG

Background: Acute Respiratory Infections (ARI) cause around 4 million under-five deaths in developing countries, including Indonesia. Air quality is strongly influenced by human activities. Purpose: This study was to analyze the relationship between PM10 concentrations in the house and the risk factors for the health conditions of the household environment and human characteristics on the incidence of respiratory disorders. Methods: This research is an analytic observational with a cross-sectional design. The number of samples calculated as many as 60 respondents were taken randomly. This research was conducted in Pulokerto Village, Gandus District, Palembang from August to December 2009. Data were collected through observation and interviews using a questionnaire, while indoor air samples were measured using the EPAM 5000 instrument by BTKL PP Palembang officers. Data were analyzed by univariate, bivariate using chi-square test, and multivariate using multiple logistic regression. Results: The results of statistical tests showed that the usage of insect repellent (p v = 0.0005, OR = 13.095, 95% CI = 3,821-44,882), smoking habits (p v = 0.0005, OR = 15.536, 95% CI = 3.114-77.519), Indoor PM10 concentration (pv=0.021, OR=3.463, 95% CI (1.186 – 10.108) While the most dominant variable affecting respiratory disorders is the usage of insect repellent. Conclusion: The factors that have the greatest influence in causing respiratory disorders are age, gender, education, population density and the use of mosquito repellent.

Bacterial Contamination Level of Indoor Air and Surface of Equipment in the Operation Room in Dil-Chora Referral Hospital, Dire Dawa, Eastern Ethiopia.

PurposeThis study investigated the bacterial contamination level of the indoor air and surface of the operation room, surgical, and gynecology wards of Dilchora Referral hospitals between January and August 2020.MethodsA laboratory based cross-sectional study was carried out on the OR and wards of Dilchora referral hospital in Eastern Ethiopia. A passive air sampling method was used to collect 128 indoor air samples; the bacterial load was enumerated and the result was expressed as colony forming units (CFU/m3). Additional qualitative analysis was carried out to identify particular bacterial species that were isolated from the indoor air and swabs taken from the surface of the equipment using conventional techniques. All laboratory data were entered and analyzed using MS Excel 2007 and SPSS version 20.ResultsThe mean bacterial counts of 94.63 CFU/dm/hr in major OR during active time as well as 509.75 and 509.38 CFU/dm/hr in male and female clothing rooms during the afternoon were unacceptable (>450 CFU/dm2). Similarly, 43.75% of the bacterial counts found in the afternoon samples fell short of Fisher’s criterion. The difference between the bacterial counts recorded in the morning and afternoon was significant (p=0.000). A total of 54 (42.2%) indoor air samples and 28 (93.3%) cotton swabs were positive for bacterial growth, with S. aureus (51.04%) and Bacillus sp (55%) being the dominant bacteria isolated from indoor air and the surface of equipment, respectively.ConclusionThe bacterial load of investigated wards is considerably “high” to “very high”, which implies a significant risk of hospital acquired infections. Therefore, devising effective control strategies targeted on surface cleansing and sterilizing of the air environment and practicing periodic microbial surveillance of the hospital environment is a paramant.

Detecting vinyl chloride by phytoscreening in the shallow critical zone at sites with potential human exposure

Chlorinated ethene (CE) contaminants are widespread in groundwater, and the occurrence of vinyl chloride (VC), among others, is a well-known issue due to its mobility, persistence, and carcinogenicity. Human exposure to VC may occur through inhalation after soil vapor intrusion into buildings at sites with shallow underground contamination. Soil vapor intrusion risk is traditionally assessed through indoor air and sub-slab sampling (direct evidence) or soil gas and groundwater surveys (indirect evidence). Phytoscreening (sampling and analysis of tree trunk matrices) was proven as a cost-effective alternative technique to indirectly detect shallow underground contamination by higher chlorinated ethenes and subsequent vapor intrusion risk. However, the technique has appeared barely capable to screen for the lower chlorinated VC, likely due to its fugacity and aerobic bio-degradability, with only one literature record to date showing successful detection in trees. We applied phytoscreening at two sites with severe CE contamination nearby residential buildings caused by illegal dumping of chlorinated pitches from petrochemical productions. The two sites show variable amounts of VC in the shallow groundwater (1e2 to 1e4 μg/L), posing potential sanitary risk issues. Former soil gas surveys did not detect VC in the vadose zone. At both sites, we sampled trunk micro-cores and trunk gas from poplar trees close to contaminated piezometers in different seasons. VC was detected in several instances, disproving the shared literature assumption of the inefficacy of phytoscreening towards this compound. Factors influencing the detectability of VC and other CEs in trees were analyzed through linear regressions. Two different conceptual models were proposed to explain the effective uptake of VC by trees at the two sites, i.e., direct uptake of contaminated groundwater at the first site and uptake of VC from an anoxic vadose zone at the second site. In planta reductive dechlorination of CEs is not expected based on current literature knowledge. Thus, the detection of VC in trunks would indicate its occurrence in the shallow underground, suggesting higher screening effectiveness of phytoscreening compared to soil gas; this has implications for indirect vapor intrusion risk assessment.

Could cattle dung burning have contributed to the epidemic of COVID-19-associated mucormycosis in India? Results of an experimental aero-mycological study.

BackgroundSeveral hypotheses have been proposed for explaining the outbreak of coronavirus disease 2019 (COVID‐19)‐associated mucormycosis in India, including the burning of cattle dung cakes, though no study has yet been conducted to support this claim.MethodsWe conducted an aero‐mycological study to evaluate whether Mucorales in the air increased during or after burning cattle dung cakes. We further compared the growth of Mucorales in the indoor air samples from houses with and without cattle. We also cultured fresh and dried cattle dung and soil samples for Mucorales.ResultsWe noted no significant difference in the proportion of air samples growing Mucorales during (4/22 [18.2%]) and after (3/2 [13.6%]) cattle dung burning than that collected immediately before (4/22 [18.2%]). Mucorales were isolated in 15.4% of the indoor air samples obtained from different houses (both rural and urban); the proportion of samples growing Mucorales was not significantly different in households with and without cattle. We also observed growth of Mucorales in 6 of the 8 [75%] fresh and 3 of the 6 [50%] dried dung samples. The most common Mucorales isolated from soil and dung samples was Lichtheimia corymbifera, while Rhizopus arrhizus was the most common species isolated from indoor air samples.ConclusionsWe found no significant increase in the proportion of air samples growing Mucorales during or after burning cattle dung cake than that before. It seems unlikely that cattle dung burning contributes to the occurrence of mucormycosis.

Definition of an Indoor Air Sampling Strategy for SARS-CoV-2 Detection and Risk Management: Case Study in Kindergartens.

In the last two years, the world has been overwhelmed by SARS-CoV-2. One of the most important ways to prevent the spread of the virus is the control of indoor conditions: from surface hygiene to ventilation. Regarding the indoor environments, monitoring the presence of the virus in the indoor air seems to be promising, since there is strong evidence that airborne transmission through infected droplets and aerosols is its dominant transmission route. So far, few studies report the successful detection of SARS-CoV-2 in the air; moreover, the lack of a standard guideline for air monitoring reduces the uniformity of the results and their usefulness in the management of the risk of virus transmission. In this work, starting from a critical analysis of the existing standards and guidelines for indoor air quality, we define a strategy to set-up indoor air sampling plans for the detection of SARS-CoV-2. The strategy is then tested through a case study conducted in two kindergartens in the metropolitan city of Milan, in Italy, involving a total of 290 children and 47 teachers from 19 classrooms. The results proved its completeness, effectiveness, and suitability as a key tool in the airborne SARS-CoV-2 infection risk management process. Future research directions are then identified and discussed.

Occurrence, exposure and risk assessment of semi-volatile organic compounds in Chinese homes

Indoor semi-volatile organic compounds (SVOCs) can have a significant impact on human health. Previous studies involved the detection of limited classes of indoor SVOCs in different regions of China. However, overall indoor pollution profiles and the associated health risks via multiple exposure pathways remain unclear. High-throughput screening of SVOCs would help clarify the overall indoor pollution status and identify high-risk pollutants. We collected indoor air and dust samples from 35 Chinese homes and investigated the occurrence of a wide range of SVOCs. Ninety-seven SVOCs including phthalate esters (PAEs), polycyclic aromatic hydrocarbons (PAHs), organophosphate esters, alcohols, fatty acids, phenols, etc., were detected in the air (total concentrations: 0.13–48 μg/m3; median: 3.4 μg/m3) and dust (total concentrations: 120–1500 μg/g; median: 490 μg/g) samples. PAEs were the most abundant, accounting for 55.3 ± 28.6% and 43.4 ± 16.9% of the total SVOC concentrations in the air and dust samples respectively. Human exposure and health risks of 34 SVOCs with detection frequencies >10% were assessed based on inhalation, ingestion and dermal absorption of SVOCs from air and dust by infants and adults. In the case of indoor SVOCs with log Koa < 9, inhalation and dermal contact with air was >90% for adults and >69% for infants. The following five SVOCs in air samples posed significant non-carcinogenic risks and are listed based on their decreasing risk level: dibutyl phthalate > phenanthrene > stearic acid > methyl palmitate > lauryl alcohol. Four PAHs with 2–4 rings posed potential carcinogenic risks, with phenanthrene exceeding the acceptable risk level of 10−4. The high risks posed by SVOCs were due to inhalation exposure. Therefore, keeping the air concentrations of SVOCs, especially that of PAEs and PAHs under check would greatly benefit human health in indoor environments.

Evaluation of air quality in indoor and outdoor environments: Impact of anti-COVID-19 measures.

This study monitors the presence of 88 volatile organic compounds (VOCs) and semi-volatile organic compounds (semi-VOCs) at the gas phase of seven indoor settings in a school in the city of Tarragona, Spain, and five outdoor locations around the city. The VOCs and semi-VOCs monitored were solvents (∑Solvents), aldehydes (∑Aldehydes), emerging organic compounds (∑EOCs), and other VOCs and semi-VOCs (∑Others). Passive sampling campaigns were performed using Carbopack X tubes followed by thermal desorption coupled to gas chromatography with mass spectrometry (TD-GC-MS). Overall, 70 of the target compounds included in the method were determined in the indoor air samples analysed, and 42 VOCs and semi-VOCs in the outdoor air samples. Our results showed that solvents were ubiquitous throughout the school at concentrations ranging from 272 μg m−3 to 423 μg m−3 and representing 68%–83% of total target compounds (∑Total). The values of ∑Total in 2021 were three times as high as those observed at the same indoor settings in 2019, with solvents experiencing the greatest increase. A plausible explanation for these observations is the implementation of anti-COVID-19 measures in the indoor settings, such as the intensification of cleaning activities and the use of hydroalcoholic gels as personal hygiene.The ∑Total values observed in the indoor settings evaluated were twenty times higher than those found outdoors. ∑Solvents were the most representative compounds found indoors (74% of the ∑Total). The concentrations of VOCs and semi-VOCs observed in the outdoors were strictly related to combustion processes from automobile traffic and industrial activities, with ∑Others contributing 58%, ∑Solvents 31%, and ∑Aldehydes 11% of the ∑Total. EOCs, on the other hand, were not detected in any outdoor sample.

Surveillance of Indoor Air Concentration of Volatile Organic Compounds in Luxembourgish Households.

Exposure to air pollution is a well-known health risk. For instance, volatile and very volatile organic compounds (VOCs and VVOCs) are known to cause respiratory, haematologic or immune diseases, and even cancer. Based on the Luxembourgish indoor pollution surveillance program, we performed an exploratory analysis for the period 2014–2019, in order (1) to evaluate the prevalence of VOCs and VVOCs in households, and (2) to estimate the risks of lifelong exposure to selected VOCs on the health of the adult population. The database included 715 indoor air samples from 159 different households. Observed VOC and VVOC levels were similar to those in neighbouring countries. Our health impact assessment identified some health risks associated with the observed concentrations in Luxembourg. Furthermore, this study shows the major public health importance of having a national indoor pollution surveillance system in place. Highlights: (1) This study provides an overview of the domestic indoor pollution in Luxembourg. (2) (V)VOCs levels in Luxembourg were similar to those in neighbouring countries. (3) The results clearly show the importance of having a surveillance system in place.

Association between maternal exposure to indoor air pollution and offspring congenital heart disease: a case\u2013control study in East China

BackgroundPrevious research suggested an association between maternal exposure to ambient air pollutants and the risk of congenital heart disease (CHD). However, the effect of individual prenatal exposure to indoor air pollutants on CHD occurrence was not reported.MethodsWe performed a hospital-based case–control study to investigate the association between personal air pollution exposure during pregnancy and the risk of CHD in offspring. A total of 44 cases and 75 controls were included from two hospitals in East China. We investigated maternal and residential environmental characteristics using a questionnaire and obtained personal indoor air samples to assess particulate matter (PM) and volatile organic compounds (VOCs) from 22–30 gestational weeks. Formaldehyde, benzene, toluene, xylene, total volatile organic compounds (TVOCs), PM2.5, and PM10 were assessed. Logistic regression was performed to assess associations and interactions between individual indoor air pollutants and CHD after adjusting for confounders. The potential residential environmental factors affecting the risks of indoor air pollutants on CHD were also assessed.ResultsMedian TVOC (0.400 vs. 0.005 mg/m3, P < 0.001) exposure levels in cases were significantly higher than controls. A logistic regression model adjusted for confounders revealed that exposure to high levels of indoor TVOCs (AOR 7.09, 95% CI 2.10–23.88) during pregnancy was associated with risks for CHD and the occurrence of some major CHD subtype in offspring. These risk effects were enhanced in pregnant women living in a newly renovated house but were mitigated by household use of smoke ventilators when cooking. We observed a positive interaction of maternal exposure to TVOCs and PM2.5 and the risk for CHD.ConclusionsMaternal exposure to indoor VOCs and PMs may increase the risk of giving birth to foetuses with CHD.

Antimicrobial Resistance in Escherichia coli from the Broiler Farm Environment, with Detection of SHV-12-Producing Isolates.

Antimicrobial resistance is an important One Health challenge that encompasses the human, animal, and environmental fields. A total of 111 Escherichia coli isolates previously recovered from manure (n = 57) and indoor air (n = 54) samples from a broiler farm were analyzed to determine their phenotypes and genotypes of antimicrobial resistance and integron characterization; in addition, plasmid replicon analysis and molecular typing were performed in extended-spectrum-beta-lactamase (ESBL) producer isolates. A multidrug-resistance phenotype was detected in 46.8% of the isolates, and the highest rates of resistance were found for ampicillin, trimethoprim–sulfamethoxazole, and tetracycline (>40%); moreover, 15 isolates (13.5%) showed susceptibility to all tested antibiotics. None of the isolates showed imipenem and/or cefoxitin resistance. Twenty-three of the one hundred and eleven E. coli isolates (20.7%) were ESBL producers and carried the blaSHV-12 gene; one of these isolates was recovered from the air, and the remaining 22 were from manure samples. Most of ESBL-positive isolates carried the cmlA (n = 23), tet(A) (n = 19), and aac(6′)-Ib-cr (n = 11) genes. The following genetic lineages were identified among the ESBL-producing isolates (sequence type-phylogroup-clonotype): ST770-E-CH116–552 (n = 12), ST117-B2-CH45–97 (n = 4), ST68-E-CH26–382/49 (n = 3), ST68-E-CH26–49 (n = 1), and ST10992-A/B1-CH11–23/41/580 (n = 4); the latter two were detected for the first time in the poultry sector. At least two plasmid replicon types were detected in the ESBL-producing E. coli isolates, with IncF, IncF1B, IncK, and IncHI1 being the most frequently found. The following antimicrobial resistance genes were identified among the non-ESBL-producing isolates (number of isolates): blaTEM (58), aac(6′)-Ib-cr (6), qnrS (2), aac(3)-II (2), cmlA (6), tet(A)/tet(B) (22), and sul1/2/3 (51). Four different gene-cassette arrays were detected in the variable region of class 1 (dfrA1-aadA1, dfrA12-aadA2, and dfrA12-orf-aadA2-cmlA) and class 2 integrons (sat2-aadA1-orfX). This work reveals the worrying presence of antimicrobial-resistant E. coli in the broiler farm environment, with ESBL-producing isolates of SHV-12 type being extensively disseminated.

An actionable annotation scoring framework for gas chromatography-high-resolution mass spectrometry.

Omics-based technologies have enabled comprehensive characterization of our exposure to environmental chemicals (chemical exposome) as well as assessment of the corresponding biological responses at the molecular level (eg, metabolome, lipidome, proteome, and genome). By systematically measuring personal exposures and linking these stimuli to biological perturbations, researchers can determine specific chemical exposures of concern, identify mechanisms and biomarkers of toxicity, and design interventions to reduce exposures. However, further advancement of metabolomics and exposomics approaches is limited by a lack of standardization and approaches for assigning confidence to chemical annotations. While a wealth of chemical data is generated by gas chromatography high-resolution mass spectrometry (GC-HRMS), incorporating GC-HRMS data into an annotation framework and communicating confidence in these assignments is challenging. It is essential to be able to compare chemical data for exposomics studies across platforms to build upon prior knowledge and advance the technology. Here, we discuss the major pieces of evidence provided by common GC-HRMS workflows, including retention time and retention index, electron ionization, positive chemical ionization, electron capture negative ionization, and atmospheric pressure chemical ionization spectral matching, molecular ion, accurate mass, isotopic patterns, database occurrence, and occurrence in blanks. We then provide a qualitative framework for incorporating these various lines of evidence for communicating confidence in GC-HRMS data by adapting the Schymanski scoring schema developed for reporting confidence levels by liquid chromatography HRMS (LC-HRMS). Validation of our framework is presented using standards spiked in plasma, and confident annotations in outdoor and indoor air samples, showing a false-positive rate of 12% for suspect screening for chemical identifications assigned as Level 2 (when structurally similar isomers are not considered false positives). This framework is easily adaptable to various workflows and provides a concise means to communicate confidence in annotations. Further validation, refinements, and adoption of this framework will ideally lead to harmonization across the field, helping to improve the quality and interpretability of compound annotations obtained in GC-HRMS.

Water as a Source of Indoor Air Contamination with Potentially Pathogenic Aeromonas hydrophila in Aquaculture.

Human activities influence the presence of potentially pathogenic bacteria in indoor air. The aim of this study was to determine the effect of the experimental rearing of European grayling and European perch in a recirculating aquaculture system on the contamination of indoor air with potentially pathogenic Aeromonas hydrophila (PPAH) and the resulting health risks to humans. The PPAH counts, their resistance to seven antibiotics, and the multiple antibiotic resistance (MAR) index were determined in samples of indoor air and water from rearing tanks. The PPAH counts were highest in the laboratory bioaerosol where two fish species were reared. The calculated indoor/outdoor ratio (I/O > 1) demonstrated that tank water was the internal source of PPAH emissions. The unconstrained PCA revealed strong positive relationships (p ≤ 0.05) between the PPAH counts in the indoor air and water samples. Most of the PPAH strains isolated from laboratory air were resistant to tetracycline, cefotaxime, and erythromycin, and 26–82% of the isolates exhibited multiple drug resistance. The values of the MAR index were similar in samples of laboratory air and water (0.23–0.34 and 0.24–0.36, respectively). Agglomerative clustering revealed two clusters of strains isolated from laboratory air and tank water. The results of this study indicate that aquaculture can be a source of indoor air contamination with PPAH.

Airborne Fungi in a Neonatal Intensive Care Unit and Operating Theater in a University Hospital

Monitoring the microbiological quality of indoor air in hospital environments is a matter of comprehensive discussion due to its influence on the transmission and spread of pathogenic microorganisms. Among the artificially air-conditioned environments, hospitals are noteworthy for being specific places for the treatment and recovery of patients. In addition to problems related to patients health and professionals health, immunocompromised patients are more exposed to microorganisms present in the air currents of the refrigeration system in these environments, which can lead to consequences such as the occurrence of outbreaks. The objective of this work was to evaluate the indoor air quality in critical hospital environments of a teaching hospital in the city of Maceió, the state of Alagoas. In addition, we sought to identify the anemophilous fungal microbiota present. Air collections were taken in the rainy season, totaling, following recommendations indicated by Resolution No. 9 of the Brazilian National Health Surveillance Agency. The study was based on determining the concentration parameter of bioaerosols in indoor and outdoor air. The fungal microbiota identification was carried out by analyzing macro and microscopic characteristics for filamentous fungi and the use of molecular tools for yeasts. The most frequent species in hospital critical environments were Cladosporium cladosporioides, Penicillium piceum, Penicillium aurantiogriseum, Cladosporium herbarum and Aspergillus oryzae. In outdoor air, the most frequently found fungi were Penicillium sp., Aspergillus sp., and Cladosporium species. Candida tropicalis, C. krusei, and C. parapsilosis were identified among the yeasts in indoor and outdoor air samples. Identifying potentially pathogenic fungi in the evaluated environments points to the need for continuous monitoring of indoor air quality. Furthermore, to avoid the widespread fungal pathogens and the consequent occurrence of outbreaks, the adoption of indoor air microbiological quality analysis programs is suggested as an essential tool in developing infection control standards. In our study, airborne fungi are reported as indoor air contaminants in critical hospital environments. This finding is noteworthy because, in general, individuals present in these environments have an immunological impairment.