What science tells us about reducing coronavirus spread from Musical instruments. It was a typical Tuesday evening rehearsal

It was a typical Tuesday evening rehearsal: About 10 musicians crowded into a small basement room, sipping beers and chatting between tunes. Brass instruments, woodwinds and drums blared, with bass lines audible from the stairwell.

Since 2004, the Rude Mechanical Orchestra has practiced in the same space, a couple of blocks from the East River in Brooklyn, N.Y. The room is cramped — chairs and music stands crowd every corner, shelves are crammed with instruments and sheet music. With no windows or AC units, air circulation is minimal.

When I walked up the stairs after practice, I had no idea that the space we’d filled with boisterous pop covers and protest tunes would sit quiet for more than a year. The COVID-19 pandemic shut down the world in March 2020, isolating musicians like me from the art we love. Millions of high school and college musicians were barred from their band rooms, children’s lessons were canceled and professionals lost performance opportunities and income streams.

Though restrictions are now easing, we still face questions about how our instruments play into infection risk. Wind instruments — brasses as well as woodwinds like my clarinet — produce sound through human breath. And human breath spreads COVID-19. So how can we perform while keeping ourselves and our audiences safe, during the pandemic and beyond? To find answers, wind musicians, including myself, turned to science.

An ill wind
The hazards of live music hit home when news broke of a superspreader event among members of the Skagit Valley Chorale in Washington state. On March 10 — the same day as my band’s final rehearsal — 61 members had gathered to sing. By the time Gov. Jay Inslee instituted a stay-at-home order two weeks later, 52 members of the choir had either tested positive for the new coronavirus or were assumed to have it. Three singers were hospitalized, and two died.

The group had been careful, avoiding physical contact such as handshakes and hugs, putting plenty of space between their chairs and using hand sanitizer. At that time, the U.S. Centers for Disease Control and Prevention and other public health agencies were primarily telling people to avoid close contact and contaminated surfaces to reduce transmission risks. But many musicians quickly realized that something else was going on.

“When we saw the Skagit Valley choir spread, we knew right away that [the coronavirus] was spreading via aerosol,” says Mark Spede, director of bands at Clemson University in South Carolina. He is one of the lead researchers on a coalition that developed COVID-19 protocols for performing arts students. It was “pretty clear,” he says, that the virus was spreading through the air. On May 15, 2020, Skagit County health department staff reported in Morbidity and Mortality Weekly Report that the “act of singing, itself, might have contributed to transmission through emission of aerosols.”

I quickly realized that wind instruments like mine had to pose a similar danger. To play it safe, most wind musicians stopped playing together. My band briefly entertained the idea of practicing outside, but as New York City shut down, we switched to virtual rehearsals. These meetings were a poor substitute for in-person sessions. As anyone who’s tried to sing “Happy Birthday” over Zoom can tell you, videocalling platforms just don’t cut it for music practice. These platforms are built to highlight one speaker at a time, creating a painful lag in sound when people try to sing or play simultaneously (SN: 4/24/21, p. 22).

“School band shut down,” recalls 16-year-old Hannah Scheuer, a bandmate of mine and a student in the New York City public school system. Unable to enter the school building for months, classmates who rented instruments from the school couldn’t bring them home to practice. A survey conducted in late April by Spede and colleagues revealed that out of 30,000 U.S. high school and college music programs, about one-third had no in-person rehearsals through the end of the 2020–2021 school year.

Musicians in studies

Facing a lockdown without the camaraderie of rehearsals, musicians wanted answers about the risks their instruments might pose in spreading COVID-19. Some went as far as becoming study subjects to find out.

The Minneapolis-based Minnesota Orchestra, for instance, reached out to Jiarong Hong, a mechanical engineer at the nearby University of Minnesota. A July 2020 release of his study on indoor transmission of the coronavirus had drawn media attention; the study was later published in the January 2021 Journal of Aerosol Science. Catching wind of this work, the orchestra asked Hong and colleagues to “provide scientifically driven guidelines to help them get back to their work safely,” Hong says. His lab set up experiments with the musicians, which led to one of the first studies on the subject.

Engineer Lia Becher at the Bauhaus-Universität Weimar in Germany had an experience similar to Hong’s. When a colleague’s video demonstrating how air spreads after a cough went viral, musicians asked Becher and her lab group how air would spread out of their instruments. So she worked with local musicians to meticulously track the dispersion of air from instruments with mouthpieces.

Meanwhile, Spede and James Weaver, director of performing arts and sports for the National Federation of State High School Associations in Indianapolis, convened a group of concerned music teachers and arts organizations. They worked with mechanical engineers at the University of Colorado Boulder and the University of Maryland in College Park to study the risks posed by different performance activities, in the hopes of bringing students back to classrooms for fall 2020.

These studies and others like them fall into two categories, notes Juliette O’Keeffe, an environmental health scientist at the National Collaborating Centre for Environmental Health in Vancouver. Some, she explains, visualize the air coming out of an instrument (a qualitative method), while others measure properties of the air particles that emerge, such as size, concentration and distance traveled (a quantitative method). O’Keeffe conducted a review of studies that examined aerosols emitted from instruments and she posted her findings on her institution’s website on September 23, 2020.

Becher and colleagues employed qualitative methods, visualizing the air with a special mirror called a schlieren mirror. Using the temperature and pressure differences between static air and exhaled air, the mirror turns air patterns into visual light patterns. Videos produced by Becher’s team show exactly how air comes out of different instruments, in what looks like roiling puffs of smoke.

Hong’s lab followed quantitative methods, using an aerodynamic particle sizer — a special spectrometer that measures the diameters of tiny particles. These instruments can determine the sizes of aerosols that may spread the coronavirus (SN Online: 5/18/21).

Spede and Weaver’s collaborators used both quantitative and qualitative methods. This included the schlieren mirror and measurements taken in a dedicated aerosol testing room with a ventilation system that allows engineers to isolate the aerosols that emerged from the various instruments.

Which winds pose the highest risks?
For singers, all air comes directly out of the windpipe. But for wind musicians, once the air leaves the windpipe, its travel pattern depends on the instrument.

Hong’s team measured these patterns with musicians from the Minnesota Orchestra. The study’s findings, which he also published in the January 2021 Journal of Aerosol Science, measured risk by comparing the size and concentration of air particles dispersed by musicians with those emitted when a person speaks. Tubas were lowest risk, producing fewer particles than a person speaking. Flutes, French horns and larger woodwinds released similar levels of aerosols as a speaking person. Oboes, trombones and especially trumpets were all higher risk, spreading more aerosols than a person speaking.

Hong’s research provides specific aerosol sizes and concentration measurements for individual instruments. But this work, like other studies in this field, used very small sample sizes of one or two musicians to characterize an instrument’s air dispersion.

Originally Published By Science News

By Arsalan Ahmad

Arsalan Ahmad is a Research Engineer working on 2-D Materials, graduated from the Institute of Advanced Materials, Bahaudin Zakariya University Multan, Pakistan.LinkedIn: https://www.linkedin.com/in/arsalanahmad-materialsresearchengr/