Aerosol transmission of human pathogens: From miasmata to modern viral pandemics and their preservation potential in the Anthropocene record

Ongoing uncertainty over the relative importance of aerosol transmission of COVID-19 is in part rooted in the history of medical science and our understanding of how epidemic diseases can spread through human populations. Ancient Greek medical theory held that such illnesses are transmitted by airborne pathogenic emanations containing particulate matter ("miasmata"). Notable Roman and medieval schol-ars such as Varro, Ibn al-Khatib and Fracastoro developed these ideas, combining them with early germ theory and the concept of contagion. A widely held but vaguely defined belief in toxic miasmatic mists as a dominant causative agent in disease propagation was overtaken by the science of 19th century micro-biology and epidemiology, especially in the study of cholera, which was proven to be mainly transmitted by contaminated water. Airborne disease transmission came to be viewed as burdened by a dubious his-torical reputation and difficult to demonstrate convincingly. A breakthrough came with the classic mid -20th century work of Wells, Riley and Mills who proved how expiratory aerosols (their "droplet nuclei") could transport still-infectious tuberculosis bacteria through ventilation systems. The topic of aerosol transmission of pathogenic respiratory diseases assumed a new dimension with the mid-late 20th cen-tury "Great Acceleration" of an increasingly hypermobile human population repeatedly infected by dif-ferent strains of zoonotic viruses, and has taken centre stage this century in response to outbreaks of new respiratory infections that include coronaviruses. From a geoscience perspective, the consequences of pandemic-status diseases such as COVID-19, produced by viral pathogens utilising aerosols to infect a human population currently approaching 8 billion, are far-reaching and unprecedented. The obvious and sudden impacts on for example waste plastic production, water and air quality and atmospheric chem-istry are accelerating human awareness of current environmental challenges. As such, the "anthropause" lockdown enforced by COVID-19 may come to be seen as a harbinger of change great enough to be pre-served in the Anthropocene stratal record.(c) 2021 China University of Geosciences (Beijing) and Peking University. Production and hosting by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/ licenses/by-nc-nd/4.0/).

VIRTUAL TEACHING AND IMPROVEMENT OF KNOWLEDGE IN PREVENTION OF COVID-19 IN CHILDREN OF REGULAR BASIC EDUCATION

The present research aims to determine the effect of virtual teaching on knowledge for the prevention of COVID-19. Using quasi-experimental pretest-posttest study methods, with a sample of 46 schoolchildren in the sixth grade of primary school at the Colegio Nacional Aplicacion UNHEVAL of Huanuco. Knowledge of COVID-19 prevention was assessed by means of a questionnaire. Non-parametric statistical analysis was used with the Wilcoxon test. The results showed that the average score obtained in the knowledge of COVID-19 prevention before e-learning was 10.4, and after e-learning it was 16.4, finding significant differences with p=0.000. Likewise, significant differences were found in the dimensions of hand washing (2.9 to 3.6), correct use of masks (1.7 to 2.7), social distancing (2.6 to 3.4), home entry protocol (2.2 to 4.1) and home exit protocol (0.9 to 2.5), all with p=0.000. The application of virtual teaching favors the increase of knowledge for the prevention of COVID-19 in primary school students.

COVID-T: A functional platform to monitor SARS-CoV-2-specific T cell responses in vaccinated individuals and COVID-19 recovered patients

The rapid spread of the SARS-CoV-2, the causative agent of the emergent pandemic disease COVID-19, requires the urgent commitment of the immunology community to understand the adaptive immune response developed by COVID-19 convalescent patients and individuals vaccinated with different strategies and schemes, with the ultimate goal of implementing and optimizing health care and prevention policies. Currently, assessment of SARS-CoV-2-specific immunity is mainly focused on the measurement of the antibody titers and analysis of their neutralizing capacity. However, a considerable proportion of individuals lack humoral responses or show a progressive decline of SARS-CoV-2-specific neutralizing antibodies. In order to study the cellular response of convalescent patients and vaccinated individuals, we have developed the 'COVID-T Platform', an optimized strategy to study SARS-CoV-2-specific T cell responses. This platform allows assessment of the nature, magnitude and persistence of antigen-specific T-cell immunity in COVID-19-convalescent patients and vaccinated individuals. Moreover, it gives the opportunity to study cellular responses against emerging coronavirus variants and to identify individuals with cross-reactive immunity against seasonal coronaviruses.

Overview on the occurrence of microplastics in air and implications from the use of face masks during the COVID-19 pandemic.

Environmental pollution from microplastics (MPs) in air is a matter of growing concern because of human health implications. Airborne MPs can be directly and continuously inhaled in air environments. Especially high MPs contributions can be found in indoor air due to the erosion and breakage of consumer, domestic and construction products, although there is little information available on their sources and concentrations and the risks they might pose. This is in part due to the fact that sampling and analysis of airborne MPs is a complex and multistep procedure where techniques used are not yet standardized. In this study, we provide an overview on the presence of MPs in indoor air, potential health impacts, the available methods for their sampling and detection and implications from the use of face masks during the COVID-19 pandemic.

COVID-19 face masks: A new source of human and environmental exposure to organophosphate esters.

For the first time, organophosphate ester (OPE) content was studied in different types of surgical, self-filtering (KN95, FFP2, and FFP3) and reusable face masks used for COVID-19 prevention. OPEs were detected in all mask samples, although in highly variable amounts which ranged from 0.02 to a maximum of 27.7 µg/mask, with the highest mean concentrations obtained for KN95 masks (11.6 µg/mask) and the lowest for surgical masks (0.24 µg/mask). Twelve out of 16 tested analytes were detected, with TEP, TPHP, TNBP, TEHP and TClPP being the most common OPEs as well as present at the highest concentrations. The non-carcinogenic and carcinogenic risks of OPE inhalation were calculated as being always several orders of magnitude lower than threshold levels, indicating that the use of face masks is safe with regard to OPE contamination. However, given the wide range of OPEs observed in different masks, it can be concluded that some masks (e.g. reusable) are less OPE-contaminated than others (e.g. KN95). With regard to environmental pollution, the disposal of billions of face masks is adding to the already substantial levels of microplastics and associated toxic additives worldwide, an impact that is lessened by use of reusable masks, which also have the lowest economic cost per user. However, in situations of relatively high risk of viral inhalation, such as poorly ventilated indoor public spaces, we recommend the use of FFP2 masks.