Role of indoor aerosols for COVID-19 viral transmission: a review

Abstract

The relationship between outdoor atmospheric pollution by particulate matter and the morbidity and mortality of coronavirus disease 2019 (COVID-19) infections was recently disclosed, yet the role of indoor aerosols is poorly known. Since people spend most of their time indoor, indoor aerosols are closer to human occupants than outdoors, thus favoring airborne transmission of COVID-19. Therefore, here we review the characteristics of aerosol particles emitted from indoor sources, and how exposure to particles affects human respiratory infections and transport of airborne pathogens. We found that tobacco smoking, cooking, vacuum cleaning, laser printing, burning candles, mosquito coils and incenses generate large quantities of particles, mostly in the ultrafine range below 100 nm. These tiny particles stay airborne, are deposited in the deeper regions of human airways and are difficult to be removed by the respiratory system. As a consequence, adverse effects can be induced by inhaled aerosol particles via oxidative stress and inflammation. Early epidemiological evidence and animal studies have revealed the adverse effects of particle exposure in respiratory infections. In particular, inhaled particles can impair human respiratory systems and immune functions, and induce the upregulation of angiotensin-converting enzyme 2, thus inducing higher vulnerability to COVID-19 infection. Moreover, co-production of inflammation mediators by COVID-19 infection and particle exposure magnifies the cytokine storm and aggravates symptoms in patients. We also discuss the role of indoor aerosol particles as virus carriers. Although many hypotheses were proposed, there is still few knowledge on interactions between aerosol articles and virus-laden droplets or droplet nuclei.

Corona and polio viruses are sensitive to short pulses of W-band gyrotron radiation

“…Handling the SARS-CoV-2 pandemic requires various means to prevent person-to-person virus spread (Dai et al 2021 ). Transmission of SARS-CoV-2 is not completely understood, but it is thought to occur via direct contact with an infectious person, exposure to respiratory droplets as well as indirect contact with various contaminated surfaces (Zhang et al 2020 ; Chia et al 2020 ; Choi et al 2021a ; Khan et al 2021 ; Chen et al 2021 ). Thus, decontamination means of surfaces and closed spaces are of need.…”

Prevalence and Associated Risk Factor of COVID-19 and Impacts of Meteorological and Social Variables on Its Propagation in Punjab, Pakistan

“…A significant nonlinear association has been observed among daily COVID-19 cases, meteorological variables, and air quality index on different lag days over Dhaka (Islam et al 2021). Similarly, the dust particles inhaled by humans can damage the respiratory system and immunity causing high vulnerability to COVID-19 infection (Chen et al 2021 ).…”

The Covid-19 Incidence in Italian Regions Correlates with Low Temperature, Mobility and Pm10 Pollution but Lethality Only with Low Temperature

“…The warmest provinces of some Italian Regions were found to have the lowest CFR for COVID-19. 31 It was also found that the areas with tropical climates (Netherlands, France, and the United Kingdom) had lower CFRs than those in some other countries in Europe. 32 Coherently, the equatorial nations had lower COVID-19 lethality than other countries (with the exclusion of Ecuador, which had a cold climate due to the mean altitude).…”