COVID-19: Transmission possible through breathing and speaking

Spread of COVID-19 through breathing and talking

Breathing and speaking are transmission paths for SARS-CoV-2. The released aerosols are able to infect other people. So far, it has been the known main transmission methods that have been of particular concern, such as coughing, sneezing and transmission through infected surfaces. This is the result of a current study.

A recent study confirmed that breathing and talking from people with COVID-19 were enough to infect healthy people with the disease. In most cases, this danger is still underestimated, warn the researchers. The results of the study were published in the English-language journal "Risk Analysis".

What role do aerosols play in the transmission of SARS-CoV-2?

The role of aerosols in the transmission of SARS-CoV-2 deserves more attention. Current public health guidelines and information are slowly beginning to take aerosols more seriously as a means of transmission, mainly related to breathing and speaking of asymptomatic people. According to the researchers, the provision of guidelines for adequate inhalation protection will be important in order to further curb the spread of COVID-19.

Aerosols should be given more attention

So far, the main methods of transmission have been of concern, such as transmission to close distances (coughing and sneezing) and contact with infected surfaces. According to the researchers, more attention should be paid to inhalation of aerosols. Aerosols are small particles that remain in the air and can thus be transported over short and long distances. Reports of asymptomatic people who infect other people with COVID-19 indicate that activities such as normal breathing and speaking create tiny droplets that are carried through the air and thus infect other people.

Aerosols stay in the air for a long time and can cover long distances

Because the aerosol particles generated when speaking and breathing are so small, they remain in the air for a relatively long time before they are pulled to the ground by gravity. This enables them to be transported over longer distances. A study of SARS-CoV-1 carried out in 2006, for example, found on this topic that particles with a diameter of one to three μm can float in the air almost indefinitely. Particles with a size of 10 μm took 17 minutes, and particles with a size of 20 μm took four minutes to fall to the ground, the research group reports.

Virus remains viable and infectious for hours in aerosols

A recent laboratory study also found that the virus can remain viable and infectious in aerosols for hours (it remained viable throughout the three-hour period of the study) and persists on surfaces for up to several days.

More research is needed

The concentration, survival, and transport distances for SARS-CoV-2 in aerosol form should be examined at different temperatures and humidity levels to collect more important data on possible routes of infection. The researchers report that further investigation of the airborne concentrations and the role of the dose in different parts of the airways for the progression and the severity of the disease are absolutely necessary. In addition, the potential for aerosol contamination of buildings, rooms and surfaces should be investigated in order to create a basis for decontamination protocols.

Which activities lead to a greater distribution of aerosols?

An investigation and recording of data to determine the role human activities play in the potential generation of aerosols that SARS-CoV-2 can transmit in both closed and open spaces is also appropriate, according to the research group. The researchers report that new studies should also deal with suitable measures to contain inhalation exposure to small aerosols (<5 μm) in buildings, rooms and surfaces. (as)

Author and source information

This text corresponds to the requirements of the medical literature, medical guidelines and current studies and has been checked by medical doctors.


  • Elizabeth L. Anderson, Paul Turnham, John R. Griffin, Chester C. Clarke: Consideration of the Aerosol Transmission for COVID-19 and Public Health, in Risk Analysis (published May 1, 2020), Risk Analysis

Video: Experts: Breathing, talking can spread COVID-19 (November 2021).