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AI and Immunology Considerations in Pandemics and SARS-CoV-2 COVID-19
Published in Louis J. Catania, AI for Immunology, 2021
Care for coronavirus patients is supportive in nature and may include supplemental oxygen, fluid administration, and, for critically ill patients, being managed in intensive care units and receiving rescue therapies such as extracorporeal membrane oxygenation (pulmonary ventilation). Stringent infection control is critical to preventing transmission to health care workers and other patients. Droplet precautions (e.g., personal protective equipment [PPE] including surgical or procedure mask, gown, and gloves) are indicated during the treatment of all coronavirus patients, and such protocols for droplet-spread respiratory viruses are part of hospital infection control practices. Additional respiratory precautions may also be appropriate during aerosol-generating procedures (such include loud talking, singing, and of course coughing and sneezing).46
Microbiological Hazards
Published in Dag K. Brune, Christer Edling, Occupational Hazards in the Health Professions, 2020
Aerosolized droplet nuclei less than 10 μm in diameter containing only one or a few bacilli are the primary means of transmission of tuberculosis. The risk of infection is related to the density of bacilli in the respired air.184,185 Current evidence indicates that only droplet nuclei that reach the alveoli are effective in infecting a susceptible host. Other particles are too voluminous to reach the pulmonary alveoli. Therefore, bacilli present on clothing, bed linen, and other objects contaminated by the patient do not play a significant part in infection since they cannot be dispersed into aerosols of this small size.186,187 Thin watery sputum is more easily dispersed into infective particles than viscous material. The presence of cough increases the probability of aerosol generation, as do other forceful exhalational maneuvers such as sneezing, singing, or shouting.188,189
Air Pollutants
Published in Ya. M. Grushko, A.P. Kotlobye, HANDBOOK OF Dangerous Properties of Inorganic and Organic Substances in Industrial Wastes, 2020
Present in wastes from the production of selenium and its organic derivatives. Toxicity: causes allergy and irritation of the eyes and mucous membranes, sneezing, sore throat, dry coughs, severe headache, lacrimation, and damage to the lungs and liver [74,81,103].
Estimating the reduction in SARS-CoV-2 viral load by common face masks with a simple leak model
Published in Aerosol Science and Technology, 2022
Steffen Freitag, Steven G. Howell, Kevin T. C. Jim
The larger of these two breath modes originates from an area around the vocal cords (larynx mode) where air turbulence ruptures the laryngeal mucus layer during exhalation (Johnson and Morawska 2009), while the smaller mode originates deep in the lungs. Studies show that these tiny aerosols form during inhalation when the lining fluid inside the lungs stretches and ruptures during reopening of the bronchioles that close during exhalation (Almstrand et al. 2010; Schwarz et al. 2010; Malashenko, Tsuda, and Haber 2009). A single study found an even smaller lung mode created in the lungs with a mean diameter near 0.15 µm (Holmgren et al. 2010) at 99.5% RH, which is supported by numerical modeling (Malashenko, Tsuda, and Haber 2009). Given these findings face masks not only have to protect against giant droplets produced during sneezing, coughing and speaking but also against submicrometer aerosol. This is particularly important as these fine particles are readily inhaled deep into the respiratory tract of a susceptible individual (Heyder et al. 1986).
Toxic and carcinogenic effects of hexavalent chromium in mammalian cells in vivo and in vitro: a recent update
Published in Journal of Environmental Science and Health, Part C, 2022
Shehnaz Islam, Sreejata Kamila, Ansuman Chattopadhyay
Occupational exposures to Cr (VI) compounds can be quite severe. In chrome plating workshops with a ventilation system, the concentrations of Cr (VI) usually range from 10 to 30 μg/m3, while in workshops without proper exhaust system the concentrations can be as high as 120 μg/m3.6 Workers in the chrome ore manufacturing units exposed to high levels of Cr (VI) are known to develop respiratory cancers like cancers of the lung, nose, and nasal sinuses more often than the rest of the population.141 Even breathing of Cr (VI) at a concentration as low as 2 μg/m3 can cause sneezing and irritation of the nasal mucosa.
Quantitative risk assessment of COVID-19 aerosol transmission indoors: a mechanistic stochastic web application
Published in Environmental Technology, 2023
Lucas Rocha-Melogno, Katherine Crank, Michael H. Bergin, Gregory C. Gray, Kyle Bibby, Marc A. Deshusses
We define aerosol transmission as the exposure to a pathogen through inhalable aerosol particles <100 μm in size [2], regardless of time and distance, leading to infection. We also highlight that these aerosols are emitted by a contagious person when breathing, speaking, sneezing or coughing [28,29], not only during ‘aerosol-generating procedures’ [30]. We do not include modelling of particles >100 μm in size, which we refer to as droplets, too big to be inhaled [2] and only relevant for short range transmission.