Please have a look at this useful RG link.

https://onlinelibrary.wiley.com/doi/full/10.1002/hpm.3095

Recent findings have found that there is relation between aerosol and transmission of COVID-19.

You may refer the following discussion:

https://www.who.int/news-room/commentaries/detail/modes-of-transmission-of-virus-causing-covid-19-implications-for-ipc-precaution-recommendations.

Please have a look at this useful RG link.

https://onlinelibrary.wiley.com/doi/full/10.1002/hpm.3095

Also, see the following PDF attachment.

Please, check the following links. They may be helpful for you. Thank you.

-Sabuj Das

https://www.frontiersin.org/articles/10.3389/fpubh.2019.00023/full

https://link.springer.com/article/10.1007/s10668-020-00704-2

There is a large scientific agreement that COVID‐19 can be transmitted by airborne route effectively. Based on the 3 h viability of SARS‐CoV‐2 in air, exposure, inhalation and infection could occur minutes or a few hours later near and far from an aerosol source in a stagnant atmosphere. https://onlinelibrary.wiley.com/doi/full/10.1002/hpm.3095

Although the direct transmission from infected person/s is the primary source of aerosols and droplets, other scenarios such as medical procedures, surgeries, fast-running tap water and toilet flushes also generate aerosols contaminated with infectious pathogens. The most common types of viruses causing infections in the respiratory tract through aerosol transmission are influenza viruses, rhinoviruses, coronaviruses, respiratory syncytial viruses (RSVs), and parainfluenza viruses ... has postulated three modes in which the influenza virus can be transmitted: aerosol transmission, droplet transmission, and self-inoculation of the nasal mucosa by contaminated hands. Another classification is often referred to as the term of ‘airborne transmission’ to describe the disease spread by small droplet aerosols and droplet nuclei, while the term ‘droplet transmission’ to describe infection by large droplet aerosols. Besides, the direct contact and fomite transmission produced by aerosol-generating medical procedures (AGMPs) can also be considered as potential transmission pathways https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7293495/

The SARS-CoV-2 is often said to be transmitted through droplets generated when a symptomatic person coughs, sneezes, talks, or exhales. Some of these droplets are too heavy to remain in the air, and rather fall on nearby floors or surfaces. Fomites collect droplets contaminated with SARS-CoV-2, and touching of such surfaces by a susceptible host would get infected. However, some droplets, when ejected from an infected person, convert to aerosol particles (also known as bioaerosols) with relatively smaller aerodynamic diameters and, consequently, become airborne. Such virus-laden aerosol particles are capable of infecting people who inhale such particles, thereby spreading the disease. Further, there have been several transport phenomena where larger droplets become smaller through evaporation so that such smaller particles are called droplet nuclei. Such aerosol particles with the encapsulation of viruses could be termed as bioaerosols or droplet nuclei; hence, the term ‘aerosol’, ‘bioaerosol’, and ‘droplet nuclei’ is used in this paper interchangeably. The scenarios in respect of the generation of droplets and aerosol, particularly in the indoor environment, have not been adequately understood, and thus, insights into the plausible mechanisms are worthy of being explored. ... for the first time, has explored the characteristics of droplets and aerosol from human expiratory activities with chest infections .... has observed that 95% of particles were often smaller than 100 μm, and the majority were between 4 and 8 μm. The findings corroborated that breathing and exhalation originated from the nose have shed up to a few hundreds of droplets of which some were aerosols. In contrast, talking, coughing, and sneezing have produced more aerosols than droplets https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7293495/

The physicochemical processes affecting the fate of airborne aerosols constitute evaporation, interaction with other types of particles, transport, and removal from the air by deposition on solid surfaces. Particles in the air are often subjected to Brownian motion, gravity, electrostatic forces, thermal gradients, electromagnetic radiation, turbulent diffusion, and inertial forces. Of these mechanisms, the diffusion is a key mechanism of transmitting viruses with particles in the lower sub-micrometer range, together with other aerosol particles. For droplets larger than 1 μm, gravity becomes significant than Brownian motion in deciding the fate of such particles. Under the standard atmospheric conditions, droplets smaller than 100 μm often evaporate before reaching the ground, and the evaporated droplet residues linger in the air for prolonged periods. When the droplets contain infectious bioaerosols, such as viruses, bioaerosols will remain in the air, even after the liquid content evaporates. However, the time interval that a virus survives in the air varies from one type of bioaerosol to another type. Droplets in the range of 0.5–20.0 μm lingering in the air are more likely to be retained in the respiratory tract and produce the infection. However, droplets seem to be not present in the air for longer periods; instead, evaporation takes place, transforming droplets to bioaerosol residues, which could linger in the air for extended periods. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7293495/

Hi, dear Ujjayini Priya, please read the following article on environmental pollution and covid-19 recently accepted in AAQR journal:

https://aaqr.org/articles/aaqr-20-07-covid-0434

Best regards, Giovanni

Giovanni Angelo Salini Thanks a lot for your valuable and huge contribution. The topic is clear to me now. May the almighty God bless you dear. Wish you all the very best.

Dear Arvind Singh Thank you so much for your support. My best wishes are always for you. Stay blessed.

Chinaza Godswill Awuchi Thank you so much for your huge contribution dear. May the Almighty God grant you success and good health.

Sabuj Das Thanks for your valuable contribution. Stay safe and blessed.

Current evidence suggests that transmission of SARS-CoV-2 occurs primarily between people through direct, indirect, or close contact with infected people through infected secretions such as saliva and respiratory secretions, or through their respiratory droplets, which are expelled when an infected person coughs, sneezes, talks or sings.

Airborne transmission is defined as the spread of an infectious agent caused by the dissemination of droplet nuclei (aerosols) that remain infectious when suspended in air over long distances and time. (11) Airborne transmission of SARS-CoV-2 can occur during medical procedures that generate aerosols (“aerosol generating procedures”).(12) WHO, together with the scientific community, has been actively discussing and evaluating whether SARS-CoV-2 may also spread through aerosols in the absence of aerosol generating procedures, particularly in indoor settings with poor ventilation.

The virus can also spread after infected people sneeze, cough on, or touch surfaces, or objects, such as tables, doorknobs and handrails. Other people may become infected by touching these contaminated surfaces, then touching their eyes, noses or mouths without having cleaned their hands first