airborne contamination
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PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0260187
Author(s):  
Lucie Delaroche ◽  
Mélanie Bertine ◽  
Pierre Oger ◽  
Diane Descamps ◽  
Florence Damond ◽  
...  

To date, there is limited information about the presence of SARS-CoV-2 in semen especially in the acute phase of the infection. While available data from cohort studies including a total of 342 patients in the acute or recovery phase of the infection are reassuring, one study mentioned detecting virus in the semen of 6/38 COVID-19 patients. Here we assessed SARS-CoV-2 presence in the semen of COVID-19 positive patients in the acute stage of infection, within 24 hours of the positive nasopharyngeal swabs. Semen, seminal plasma and spermatozoa pellet were screened for SARS-CoV-2 and manual or airborne contamination during semen sampling. Among the 32 COVID-19 volunteers, the median interval from the onset of symptoms to semen collection was 4 days [IQR: 0–8]. Only one presented positive SARS-CoV-2 PCR in semen and seminal plasma fractions, although the spermatozoa pellet was negative. Viral cultures were all negative. We observed slightly higher concentrations of bacterial DNA in the SARS-CoV-2 positive specimen than in all negative samples. The bacteria identified neither confirm nor rule out contamination by oropharyngeal secretions during collection. SARS-CoV-2 was rarely present in semen during the acute phase of the disease. This very rare situation could be connected to oral or manual contamination during semen collection. The possible presence of SARS-CoV-2 in semen calls for nasopharyngeal viral testing and strict hygiene protocols during semen collection before assisted reproductive attempts.


Author(s):  
Danúbia da Cunha De Sá-Caputo ◽  
Ana Carolina Coelho-Oliveira ◽  
Anelise Sonza ◽  
Laisa Liane Paineiras-Domingos ◽  
Redha Taiar ◽  
...  

Background: The facemasks use has been discussed to prevent respiratory disease due airborne contamination. The aim of this study was to perform a systematic review about the face masks use to avoid airborne contamination during COVID-19 pandemic and related conditions, registered (PROSPERO-CRD42020198347) and performed according PRISMA. Methods: PubMed, Embase and Scopus databases were used to collect data. Observational studies, published in 2020, and English language, were included. Two reviewers independently identified records through database search and reference screening and disagreements were resolved by a third reviewer. Six studies were included. Results: The works investigated about the use of masks (different types) to prevent droplets dissemination with virus or bacterial suspension and decrease COVID-19 transmission routes, comfort, or temperature. The studies have moderate to critical risk of bias and the level of evidence is III-2. Conclusion: It is recommended facemask use to prevent droplets from escaping airborne and infecting other people, although there are different percentages of protection and can be possible a discomfort related the use. Further clinical trials to the effectiveness of face mask to avoid airborne contamination during the COVID-19 pandemic and the factors interfering with their effectiveness should be conducted.


2021 ◽  
Vol 3 (3) ◽  
pp. 102-105
Author(s):  
Vinay S Dua ◽  
Amandeep Kaur ◽  
Ankit Sikri ◽  
Mitasha Sachdeva

A new coronavirus (Sars-CoV-2) was detected in China at the end of 2019 and has since caused a worldwide pandemic. This virus is responsible for an acute respiratory syndrome (COVID-19), distinguished by a potentially lethal interstitial bilateral pneumonia. As Sars-CoV-2 is highly infective through airborne contamination, the high infection risk in the dental environment is a serious problem for both professional practitioners and patients. This literature overview at analyzing various reports available on oral symptoms along with possible causation, their relationship to the time of occurrence of clinical symptoms of this global pandemic.


Author(s):  
Gavin P. Horn ◽  
Daniel Madrzykowski ◽  
Danielle L. Neumann ◽  
Alexander C. Mayer ◽  
Kenneth W. Fent

2021 ◽  
Author(s):  
◽  
Raymond Alan Hoare

<p>The surface chemistry of the 001 face of cleaved mica sheets was studied with a view to understanding some of the fundamental processes underlying the phenomenon of fixation of phosphate by soils. Radiochemical techniques were developed to make quantitative studies of the adsorption, an important part of these being practical procedures for obtaining sufficient cleanliness and freedeom from airborne contamination. Lack of uniformity of adsorption, as shown by autoradiography, was taken to indicate contamination, and techniques were developed to avid this. Other techniques enabled the continuous monitoring of the sample during adsorption or desorption kinetic experiments. It was shown that adsorption of phosphate on the untreated mica sheets was low, but the adsorption was greatly enhanced if the mica had been treated with aqueous solutions of certain cations such as gallium, aluminium and iron. Form the measurement of the amount of phosphate adsorbed, as a function of the conditions of aluminium treatment, it was concluded that the phosphate could be absorbed by at least three different processes, all of which could be of importance in phosphate fixation by soils. As well as these processes, which occurred on clean, flat, mica surfaces, there were others, involving the edges of mica and sheets, and unknown, but probably organic, films on both mica and air-water surfaces. These could all be of comparable importance in soils. The kinetic measurements of phosphate adsorption and desorption on aluminium-treated mica indicated that many hours were required for attainment of equilibrium, and were quantitatively consistent with the hypothesis that in some cases the adsorption and desorption kinetics were controlled by diffusion of phosphate into particles of some material, possibly a hydrous oxide, adsorbed on the mica. The existence of such particles was supported by the fact that up to one phosphate molecule per two square Angstrom units of mica surface was adsorbed, (and this did not appear to be a value at which the surface was saturated.) Kinetic measurements of 67 Ga sorption processes were consistent with diffusion of gallium through a thin water film, with a diffusion coefficient several orders of magnitude lower than that of single ions in free solution. This may indicate that the gallium was adsorbing as particles, in agreement with the requirements of the phosphate experiments.</p>


2021 ◽  
Author(s):  
◽  
Raymond Alan Hoare

<p>The surface chemistry of the 001 face of cleaved mica sheets was studied with a view to understanding some of the fundamental processes underlying the phenomenon of fixation of phosphate by soils. Radiochemical techniques were developed to make quantitative studies of the adsorption, an important part of these being practical procedures for obtaining sufficient cleanliness and freedeom from airborne contamination. Lack of uniformity of adsorption, as shown by autoradiography, was taken to indicate contamination, and techniques were developed to avid this. Other techniques enabled the continuous monitoring of the sample during adsorption or desorption kinetic experiments. It was shown that adsorption of phosphate on the untreated mica sheets was low, but the adsorption was greatly enhanced if the mica had been treated with aqueous solutions of certain cations such as gallium, aluminium and iron. Form the measurement of the amount of phosphate adsorbed, as a function of the conditions of aluminium treatment, it was concluded that the phosphate could be absorbed by at least three different processes, all of which could be of importance in phosphate fixation by soils. As well as these processes, which occurred on clean, flat, mica surfaces, there were others, involving the edges of mica and sheets, and unknown, but probably organic, films on both mica and air-water surfaces. These could all be of comparable importance in soils. The kinetic measurements of phosphate adsorption and desorption on aluminium-treated mica indicated that many hours were required for attainment of equilibrium, and were quantitatively consistent with the hypothesis that in some cases the adsorption and desorption kinetics were controlled by diffusion of phosphate into particles of some material, possibly a hydrous oxide, adsorbed on the mica. The existence of such particles was supported by the fact that up to one phosphate molecule per two square Angstrom units of mica surface was adsorbed, (and this did not appear to be a value at which the surface was saturated.) Kinetic measurements of 67 Ga sorption processes were consistent with diffusion of gallium through a thin water film, with a diffusion coefficient several orders of magnitude lower than that of single ions in free solution. This may indicate that the gallium was adsorbing as particles, in agreement with the requirements of the phosphate experiments.</p>


Water ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 2854
Author(s):  
Veronica Nava ◽  
Barbara Leoni

The separation of microplastics from environmental matrices is still challenging, especially for sediments where microplastics can accumulate affecting benthic organisms. Many authors have adopted different procedures, but their effectiveness has been rarely compared. The present study aims to compare the recovery rate of three different methodologies for the separation of dense microplastics from fine sediments and provide insights about contamination processes occurring in microplastic separation techniques. The protocols tested are a density separation method with NaCl and NaI, a density separation with NaI followed by a centrifugation step, and a digestion method with 10%KOH (m/v). The recovery yields of two high-density polymers of three different dimensional classes were tested. The highest recovery rate was reported for the first protocol. However, this method proved to be expensive, and unsatisfactory results were found when using merely NaCl. The digestion method was the one that was proven to be simple, reproducible, and affordable. The contamination tests highlighted as multiple filtration steps can increase the number of fibers deriving from airborne contamination. Since a unified approach for microplastic separation from sediments is still not selected, this study is of paramount importance as it provides data about the reliability of different methods widely adopted.


Author(s):  
Birgitta Lytsy ◽  
Anna Hambraeus ◽  
Bengt Ljungqvist ◽  
Ulrika Ransjö ◽  
Berit Reinmüller

Author(s):  
GAGANDEEP SINGH ◽  
NARINDER SINGH ◽  
AJEET PAL SINGH ◽  
AMAR PAL SINGH

Mucormycosis is a new angioinvasive infection caused by the ubiquitous filamentous fungus of the Mucorales order of the Zygomycete class. Mucormycosis has emerged as the third most prevalent invasive mycosis in patients undergoing hematological and allogeneic stem cell transplantation, following candidiasis and aspergillosis. Sporangiospores must be inhaled on a daily basis. Members of the Mucorales are very infrequent in nasal mucus, indicating that spores in airway mucus are removed via mucociliary transport or that there is a minimal degree of airborne contamination.


2021 ◽  
Vol 1 (1) ◽  
pp. 2-15
Author(s):  
Samuel Jônatas de Castro Lopes

Introdução: a nanotecnologia vem propiciando uma revolução tecnológica na engenharia mundial. Dentre os nanomateriais mais utilizados, os nanotubos de carbono (NTC) se destacam por suas diversas propriedades excelentes e específicas. Entretanto, as implicações a saúde de usuários que manipulam os nanotubos de carbono estão longe de serem compreendidas e cercadas de incertezas. Métodos: estudo exploratório-descritivo, baseado em uma breve contextualização acerca dos nanotubos de carbono e da nanotoxicologia, em busca de compreender as principais características morfológicas deste material, e os principais danos causados à saúde dos trabalhadores. Objetivo: propor um procedimento de segurança para manuseio de nanomateriais em laboratórios. Resultados: os laboratórios que manipulam esse tipo de tecnologia devem ser dotados de instalações específicas e possuir procedimentos operacionais que busquem controlar a exposição e a contaminação aerotransportada. Conclusão: a compatibilização da cadeia comercial e a segurança do trabalho devem ser consideradas para nanomateriais, ou seja, o diálogo entre fabricante, fornecedor, usuário final e profissionais de saúde e segurança do trabalho (SST) é de suma importância para o desenvolvimento da nanotecnologia segura.   Introduction: nanotechnology has led to a technological revolution in world engineering. Among the most used nanomaterials, carbon nanotubes (CNT) stand out for their excellent and specific properties. However, the health impacts of users who manipulate carbon nanotubes are far from being understood and surrounded by uncertainties. Methods: exploratory-descriptive study based on a brief contextualization about carbon nanotubes and nanotoxicology, in an attempt to understand the main morphological characteristics of this material, and the main damages caused to workers' health. Objective: a safety procedure for handling nanomaterials in laboratories was proposed. Results: Laboratories that handle this type of technology must be equipped with specific facilities and have operational procedures that seek to control exposure and airborne contamination. Conclusion: the compatibility of the commercial chain and work safety must be considered for nanomaterials, that is, the dialogue between manufacturer, supplier, end user and and occupational health and safety professionals is of paramount importance for the development of safe nanotechnology.


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