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Author(s):  
Priscilla Gomes da Silva ◽  
José Gonçalves ◽  
Ariana Isabel Brito Lopes ◽  
Nury Alves Esteves ◽  
Gustavo Emanuel Enes Bamba ◽  
...  

As the third wave of the COVID-19 pandemic hit Portugal, it forced the country to reintroduce lockdown measures due to hospitals reaching their full capacities. Under these circumstances, environmental contamination by SARS-CoV-2 in different areas of one of Portugal’s major Hospitals was assessed between 21 January and 11 February 2021. Air samples (n = 44) were collected from eleven different areas of the Hospital (four COVID-19 and seven non-COVID-19 areas) using Coriolis® μ and Coriolis® Compact cyclone air sampling devices. Surface sampling was also performed (n = 17) on four areas (one COVID-19 and three non-COVID-19 areas). RNA extraction followed by a one-step RT-qPCR adapted for quantitative purposes were performed. Of the 44 air samples, two were positive for SARS-CoV-2 RNA (6575 copies/m3 and 6662.5 copies/m3, respectively). Of the 17 surface samples, three were positive for SARS-CoV-2 RNA (200.6 copies/cm2, 179.2 copies/cm2, and 201.7 copies/cm2, respectively). SARS-CoV-2 environmental contamination was found both in air and on surfaces in both COVID-19 and non-COVID-19 areas. Moreover, our results suggest that longer collection sessions are needed to detect point contaminations. This reinforces the need to remain cautious at all times, not only when in close contact with infected individuals. Hand hygiene and other standard transmission-prevention guidelines should be continuously followed to avoid nosocomial COVID-19.


PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0261704
Author(s):  
Suzanna M. Storms ◽  
James F. Lowe

This pilot project investigated environmental SARS-CoV-2 presence in seven Midwestern meatpacking plants from May 2020 to January 2021. This study investigated social distancing and infection control practices and incorporated environmental sampling of surfaces and air in employee common areas. All plants increased their social distancing efforts, increased the frequency of cleaning and disinfecting worker areas, and screened for symptomatic people to prevent entry into the workplace. 575 samples from common areas were collected and evaluated with RT-qPCR for the presence of SARS-CoV-2. 42/367 surface samples were positive, while no virus was detected in air samples. Case positive data from the counties surrounding each plant showed peak positive SARS-CoV-2 cases from 12–55 days before the virus was detected in the plant, indicating that environmental sampling is likely a lagging indicator of community and plant infection.


Atmosphere ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 6
Author(s):  
Ma. Katrina Gale Estonilo ◽  
Joedith Anne Cazeñas ◽  
Carlos Josef Villafuerte ◽  
Custer Deocaris ◽  
Gloriamaris Caraos ◽  
...  

Urban air quality is increasingly being studied as a fraction of the world’s population is living in megacities. In this study, particulate matter (PM) along Taft Avenue, Manila, the Philippines, is investigated in terms of its ability to induce genetic damage in human peripheral blood lymphocytes (PBLs). Size-segregated roadside air samples were obtained from 2015–2017 near a university gate and analyzed using in vitro micronucleus (MN) and cytokinesis-block proliferation tests. While cellular proliferation was unaffected by 0–0.1 kg/m3 of PM1.0 and PM2.5, PBL cells treated with PM2.5 displayed a significantly higher micronucleus count (p = 0.03) compared to the cells treated with PM1.0. Atomic absorption spectroscopy revealed greater amounts of Cd, Ca, Pb, K, Na, and Zn in PM2.5 compared to PM1.0. The results indicate that the differences in composition of the two size fractions of air particulates are associated with their genotoxicities.


2021 ◽  
Author(s):  
Cæcilie Leding ◽  
Julia Skov ◽  
Katrine Uhrbrand ◽  
Jan Gorm Lisby ◽  
Katrine Pedersbæk Hansen ◽  
...  

Abstract Background: The diagnosis of COVID-19 is based on detection of SARS-CoV-2 in oro-/nasopharyngel swabs, but because of uncomfortness and minor risk for the tested individual during the swab procedure, detection of SARS-CoV-2 has been investigated in other biological matrixes.Methods: In this proof-of-concept study, confirmed SARS-CoV-2-infected individuals performed a daily air sample through five days. Air samples were obtained through a non-invasive electrostatic air sampler. Detection of SARS-CoV-2 RNA were determined with qRT-PCR. The association of positive samples with clinical characteristics was evaluated through mixed-effect models.Results: We obtained 665 air samples from 111 included patients with confirmed SARS-CoV-2 infection. Overall, 52 individuals (46.8%) had at least one positive air sample, and 129 (19.4%) air samples were positive for SARS-CoV-2. Patients with symptoms or a symptom duration ≤ four days had significantly higher odds of having a positive air sample. Cycle threshold values were significantly lower in samples obtained ≤ 4 days from symptom onset. Neither variant of SARS-CoV-2 nor method of air sampling were associated with a positive air sample.Conclusion: We demonstrate that SARS-CoV-2 is detectable in human breath, and suggest further evaluation of air sampling considering the non-invasive, point-of-care method.


2021 ◽  
pp. 244-264
Author(s):  
David-A. Mendels ◽  
Gary J. H. Atkinson ◽  
Silvestre Bahi ◽  
Tristan Berger ◽  
Nicolas Delmas ◽  
...  
Keyword(s):  

2021 ◽  
Vol 9 (11) ◽  
pp. 506-520
Author(s):  
Chukwuemeka Chidera Godson ◽  
◽  
Obi Chioma Maureen ◽  
Ochiabuto Ogochukwu Barbara ◽  
Nwachukwu Chinazo Adannia ◽  
...  

Background: Polluted indoor environments pose health challenges such as allergy, infections, and toxicity. Most indoor air pollution comes from hazardous non-biological and biological agents. Due to the nature of the indoor environment of libraries, it is prone to colonization by fungal species. Method: Three sampling sites were used for the study and they include Festus Aghagbo Nwako Library, Main campus Awka, Medical Library, Nnewi Campus and Library Complex, Agulu campus. A total of 100 air samples were analyzed Using the Zefon A6 Single-stage microbial air sampler and Malt Extract Agar supplemented with 0.05mg/ml of chloramphenicol while 16 nasal swabs were collected from the staff present using sterile swab sticks. The mould isolates were identified using the slide culture technique while the yeast isolates were subjected to candida chrom agar and integral yeast plus identification. Antifungal susceptibility was performed using the integral yeast plus system and the agar well diffusion technique. Results: Out of the 100 air samples, a total of 625 fungal isolates were identified of which C.lunata 201 (32.16%) was the most predominant, while P. marneffi, P. expansum, A. restrictus, A. infectoria and R. rubra 1(0.16%) occurred the least. All significant at (p≤0.01). A total of 7 fungal spores were isolated from the 16 nasal swabs and appeared thus in descending order of frequency: P. notatum, 3 (42.85%), A. niger, C. lunata, C. albicans and F. aqueductum, 1(14.3%). Antifungal Susceptibility of the 28 yeast isolates indicated that C. famata, C. laurentii and C. luteolus, were all susceptible to commonly used antifungals in the integral yeast plus system with a 100% susceptibility value, while the mould isolates showed relatively moderate susceptibility to selected antifungals. Conclusion: The organisms isolated are well known to be pathogenic especially to immunocompromised individuals. Their presence in the indoor environment of libraries serves as a risk factor to both the library staff and visitors. Adequate precautionary measures and occasional environmental surveillance need to be inculcated in order to reduce the number of fungi in the indoor environment of these libraries.


2021 ◽  
Author(s):  
Sara Shamsah ◽  
Leila Vali ◽  
Dana Al-Kayyalli ◽  
Ali A. Dashti

Abstract Aim: Antibiotic resistance is a public health concern that is linked to increased mortality, morbidity, extended hospital stays, decreased productivity, and therefore, increased financial implications. The source and dissemination of antimicrobial resistance have been linked to environmental factors, including dust storms. There is clear evidence that there has been a rapid increase in temperature in the past decades which increases the risk of sandstorms in places that had never previously experienced this phenomenon. The aim of this study is to isolate medically important micro-organisms in atmospheric air samples from outdoor spaces and inside hospital wards during sandstorms and to characterize their antimicrobial sensitivity profiles to common antibiotics.Findings: Eighty-four colonies were isolated from the target sites and identified as Staphylococcus aureus, coagulase-negative Staphylococcus, Bacillus spp., Acinetobacter spp., from hospital air samples, and Pseudomonas spp., and Staphylococcus spp. from outdoor air samples. Multi-drug resistance patterns were observed for isolates obtained from both indoor and outdoor air samples. PCR showed 6.5% of S. aureus contained mecA. Conclusion: This finding supports the notion that atmospheric air during dust storms can be counted as a source of antibiotic resistant bacteria which merits more attention especially with global warming and climate change contributing to extreme weather events.


2021 ◽  
Author(s):  
◽  
Dominic Francesco Ferretti

<p>A new GC-IRMS technique has been developed for isotopic and mixing ratio analysis of atmospheric CO2. The technique offers for the first time, N2O-free, high precision (<0.05 [per mil]) analysis of d13C and d18O from small whole-air samples. On-line GC separation of CO2 and N2O from these small samples is combined with IRMS under elevated ion source pressures. A specialised open split interface is an integral part of the inlet system and ensures a continuous flow of either sample gas or pure helium to the IRMS. The analysis, including all flushing, uses a total of 45 ml of an air sample collected at ambient pressure. Of this, three 0.5 ml aliquots are injected onto the GC column, each providing [approximately] 0.8 nmol CO2 in the IRMS source. At this sample size, d13C precision obtained is at the theoretical shot-noise limit. Demonstrated precisions for d13C, d18O, and CO2 mixing ratio (all measured simultaneously)are 0.02 [per mil], 0.04 [per mil] and 0.4 ppm respectively. The initial results from an inter calibration exercise with Atmospheric Research at the Commonwealth Scientific and Industrial Research Organisation (CSIRO), Australia achieved the International Atomic Energy Agency (IAEA) target precision for d13C. During this exercise, agreement for d18O and CO2 mixing ratio was outside the IAEA and World Meteorological Organization (WMO) target precisions for these species, however, when the measurement uncertainties of the two laboratories were considered, the differences were not significant. An inter comparison program using air samples collected at Baring Head, New Zealand and Cape Grim, Australia was also established with CSIRO and d13C, d18O and CO2 mixing ratio showed excellent agreement when combined measurement uncertainties were considered. Further inter comparisons with the Carbon Cycle Group at the National Oceanic and Atmospheric Administration Climate Monitoring and Diagnostics Laboratory (NOAA CMDL), the Institute of Arctic and Alpine Research (INSTAAR), and Scripps Institution of Oceanography (SIO) were also established. No significant differences for d13C were observed during these inter comparison programs. Therefore, these preliminary measurements suggest that the current situation between these laboratories for d13C comparisons from whole-air in glass flasks may be improved compared to the 1995 IAEA inter comparison from whole-air in high-pressure cylinders. Following these inter calibration and inter comparison exercises, temporal and spatial variations in the mixing ratio and isotopic composition of atmospheric CO2 were determined over a large region of the Pacific Ocean to demonstrate the successful use of the GC-IRMS technique. Temporal variations were observed at long-term monitoring sites in the Southern Hemisphere (Baring Head, Cape Grim, and Arrival Heights, Ross Island, Antarctica). Seasonal cycles of CO2 mixing ratio and d13C, with amplitudes of [approximately] 1 ppm and [approximately] 0.05 [per mil] respectively, were measured at Baring Head. A decline in d13C of [approximately] -0.1 [per mil]/year was observed at Arrival Heights between 1997 and 1999. Spatial variations in the Pacific Ocean were investigated by shipboard sampling programs between [approximately] 62 degrees S and [approximately] 32 degrees N. These data were consistent with a Southern Ocean sink between [approximately] 43 degrees S and [approximately] 57 degrees S. In addition, inter hemispheric gradients of d13C and CO2 mixing ratio in March and September 1998 were determined and the position and intensity of the SPCZ and ITCZ were important for the strength of these inter hemispheric gradients. Measurements performed during an upper tropospheric flight from New Zealand, to Antarctica show elevated CO2 levels and depleted d13C compared to samples obtained in the marine boundary layer over this region. A small-scale application of the technique measured soil-respired CO2 in a New Zealand Mountain Beech forest from 150 ml sample flasks that were filled to ambient pressure. These measurements determined a difference between the d13C source signature from the young and old trees of [approximately] 0.3 [per mil], which was in the correct direction but of smaller magnitude than that expected. The small sample requirements of the GC-IRMS technique ease sample collection logistics for varied research. Since initial results from an inter calibration exercise with CSIRO obtain the IAEA target precision for d13C and the technique has demonstrated its ability to successfully monitor atmospheric CO2 species from small whole-air samples, without contamination by atmospheric N2O or the use of cryogen, the technique will be a powerful tool in global carbon cycle research.</p>


2021 ◽  
Author(s):  
◽  
Dominic Francesco Ferretti

<p>A new GC-IRMS technique has been developed for isotopic and mixing ratio analysis of atmospheric CO2. The technique offers for the first time, N2O-free, high precision (<0.05 [per mil]) analysis of d13C and d18O from small whole-air samples. On-line GC separation of CO2 and N2O from these small samples is combined with IRMS under elevated ion source pressures. A specialised open split interface is an integral part of the inlet system and ensures a continuous flow of either sample gas or pure helium to the IRMS. The analysis, including all flushing, uses a total of 45 ml of an air sample collected at ambient pressure. Of this, three 0.5 ml aliquots are injected onto the GC column, each providing [approximately] 0.8 nmol CO2 in the IRMS source. At this sample size, d13C precision obtained is at the theoretical shot-noise limit. Demonstrated precisions for d13C, d18O, and CO2 mixing ratio (all measured simultaneously)are 0.02 [per mil], 0.04 [per mil] and 0.4 ppm respectively. The initial results from an inter calibration exercise with Atmospheric Research at the Commonwealth Scientific and Industrial Research Organisation (CSIRO), Australia achieved the International Atomic Energy Agency (IAEA) target precision for d13C. During this exercise, agreement for d18O and CO2 mixing ratio was outside the IAEA and World Meteorological Organization (WMO) target precisions for these species, however, when the measurement uncertainties of the two laboratories were considered, the differences were not significant. An inter comparison program using air samples collected at Baring Head, New Zealand and Cape Grim, Australia was also established with CSIRO and d13C, d18O and CO2 mixing ratio showed excellent agreement when combined measurement uncertainties were considered. Further inter comparisons with the Carbon Cycle Group at the National Oceanic and Atmospheric Administration Climate Monitoring and Diagnostics Laboratory (NOAA CMDL), the Institute of Arctic and Alpine Research (INSTAAR), and Scripps Institution of Oceanography (SIO) were also established. No significant differences for d13C were observed during these inter comparison programs. Therefore, these preliminary measurements suggest that the current situation between these laboratories for d13C comparisons from whole-air in glass flasks may be improved compared to the 1995 IAEA inter comparison from whole-air in high-pressure cylinders. Following these inter calibration and inter comparison exercises, temporal and spatial variations in the mixing ratio and isotopic composition of atmospheric CO2 were determined over a large region of the Pacific Ocean to demonstrate the successful use of the GC-IRMS technique. Temporal variations were observed at long-term monitoring sites in the Southern Hemisphere (Baring Head, Cape Grim, and Arrival Heights, Ross Island, Antarctica). Seasonal cycles of CO2 mixing ratio and d13C, with amplitudes of [approximately] 1 ppm and [approximately] 0.05 [per mil] respectively, were measured at Baring Head. A decline in d13C of [approximately] -0.1 [per mil]/year was observed at Arrival Heights between 1997 and 1999. Spatial variations in the Pacific Ocean were investigated by shipboard sampling programs between [approximately] 62 degrees S and [approximately] 32 degrees N. These data were consistent with a Southern Ocean sink between [approximately] 43 degrees S and [approximately] 57 degrees S. In addition, inter hemispheric gradients of d13C and CO2 mixing ratio in March and September 1998 were determined and the position and intensity of the SPCZ and ITCZ were important for the strength of these inter hemispheric gradients. Measurements performed during an upper tropospheric flight from New Zealand, to Antarctica show elevated CO2 levels and depleted d13C compared to samples obtained in the marine boundary layer over this region. A small-scale application of the technique measured soil-respired CO2 in a New Zealand Mountain Beech forest from 150 ml sample flasks that were filled to ambient pressure. These measurements determined a difference between the d13C source signature from the young and old trees of [approximately] 0.3 [per mil], which was in the correct direction but of smaller magnitude than that expected. The small sample requirements of the GC-IRMS technique ease sample collection logistics for varied research. Since initial results from an inter calibration exercise with CSIRO obtain the IAEA target precision for d13C and the technique has demonstrated its ability to successfully monitor atmospheric CO2 species from small whole-air samples, without contamination by atmospheric N2O or the use of cryogen, the technique will be a powerful tool in global carbon cycle research.</p>


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