Researchers compare COVID-19 transmission risk when singing, speaking and breathing

By Angela Betsaida B. Laguipo, BSNAug 21 2020

One of the vastly impacted by the coronavirus disease (COVID-19) pandemic is the world of performing arts. Many concerts, plays, and Broadway shows were canceled due to the fear that singing in an enclosed space might pose a risk for the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

Previous guidelines and research have revealed singing has been identified as a potentially “dangerous” activity following the incidence of COVID-19 case clusters in several choirs across the globe. However, there is no clear evidence that the cases were tied to singing or playing brass or woodwind instruments, which were banned in many countries.

Now, a new study* set to determine if singing and playing of woodwind and brass instruments produce more respiratory droplets and aerosols than speaking. Further, they want to know if the size and temperature of the venue will make a difference in the accumulation of aerosol droplets in the air.

Scientific experiment to measure the spread of aerosols emitted when singing is conducted in an orthopaedic operating theatre, an environment of "zero aerosol background". Image Credit: Declan Costello

This news article was a review of a preliminary scientific report that had not undergone peer-review at the time of publication. Since its initial publication, the scientific report has now been peer reviewed and accepted for publication in a Scientific Journal. Links to the preliminary and peer-reviewed reports are available in the Sources section at the bottom of this article. View Sources

Aerosol transmission of COVID-19

The World Health Organization (WHO) has recently acknowledged that SARS-CoV-2, the virus that causes COVID-19 disease, can spread via aerosols suspended in the air when infected people cough, sneeze, or talk.

In a report in May, the U.S. Centers for Disease Control and Prevention (CDC), the health agency said that singing could be considered a superspreading event involving SARS-CoV-2. In the study, after a 2.5-hour choir practice attended by 61 people, including one symptomatic index patient, 32 confirmed and 20 probable secondary COVID-19 cases were reported. From these, three patients had to be hospitalized, and two had succumbed to the infection. The report also showed that the transmission of the virus was likely facilitated by proximity, which is within the 6-feet range, during practice, and exacerbated by singing.

From there, the CDC has recommended avoiding gathering in large groups, including shows, rehearsals, and public events.

In another preliminary research in July, a team of researchers has found that singers, including those who play brass and wind instruments, produce respiratory aerosols at high rates. Put simply, they generate a lot of droplets in the air when they sing or blow.

Another study in early August, funded and supported by the National Federation of State High School Associations (NFHS) and a group of more than 124 performing arts organizations, supported the preliminary results. The second phase of the study explored aerosol from additional singers and instruments, as well as theater performers.

The results of the second phase of the study highlight the importance of masks, distance, time, airflow, and hygiene to create the safest possible environment for bringing performing arts back into rehearsal spaces, performance halls, classrooms, and band rooms.

No riskier than speaking

In the current study, called the PERFORM (ParticulatE Respiratory Matter to InForm Guidance for the Safe Distancing of PerfOrmeRs in a COVID-19 PandeMic) and conducted by experts at the Imperial College London, the researchers carried out several experiments to determine if airborne droplets are produced via breathing, speaking, singing, and playing of brass and woodwind instruments. The research is published on the preprint server ChemRxiv*.

The participants in the study sang and spoke between the decibel (dB) ranges of 50 to 60, 70 to 80, and 90 to 100.

The team has found that singing does not produce substantially more respiratory particles than speaking at a similar volume. The amount of aerosols produced depends on how loud a person is, which could have implications for live indoor performances.

To reduce the risk of coronavirus spread, the researchers recommended singing softly, offering a ray of hope for musicians who were greatly affected by the pandemic since they were restricted from performing in public.

To arrive at the findings of the study, the team recruited 25 professional singers to breathe, talk, cough, and sing into funnels where the small aerosols suspended in the air were measured. The singers performed the activities in an orthopedic operating theater, which is ideal for the experiment because it does not have background aerosols.

The team has found that the lowest volume singing and speaking produced a similar mass of aerosols as breathing. They concluded that singing softly can reduce the risk of COVID-19 transmission.

“Our research has provided a rigorous scientific basis for Covid-19 recommendations for arts venues to operate safely, for both the performers and audience, by ensuring that spaces are appropriately ventilated to reduce the risk of airborne transmission,” Jonathan Reid, a Professor of Physical Chemistry at the University of Bristol, said in a statement.

This news article was a review of a preliminary scientific report that had not undergone peer-review at the time of publication. Since its initial publication, the scientific report has now been peer reviewed and accepted for publication in a Scientific Journal. Links to the preliminary and peer-reviewed reports are available in the Sources section at the bottom of this article. View Sources