To Test Spread of Coronavirus, These Scientists Put on a Concert

LEIPZIG, Germany — The German pop singer Tim Bendzko was trying his best to energize the crowd at Quarterback Immobilien Arena here on Saturday morning. Flanked by band members and backup singers, he bounced across a stage at the indoor concert and sports venue, thrusting his microphone toward about 1,400 tightly packed audience members, prompting them to sing along.

The response was a muffled hum — unsurprising, given that the audience members were wearing masks and sitting in sweltering heat. Still, an undaunted Mr. Bendzko thanked them and said, “On this day, you are saviors of the world.”

They were not typical concertgoers, but volunteers in an elaborate study by a team at Martin Luther University Halle-Wittenberg called Restart 19. Each attendee, outfitted with a digital location tracker and hand disinfectant laced with fluorescent dye, were carefully positioned on seats as part of one of the first experiments by scientists to track the risks of coronavirus infection posed by large, indoor events.

Researchers hope to use their results to determine which elements of events like this pose the greatest risk for transmission and help create guidelines for limiting such dangers and safely restarting live performances around the world.

The live-music and events sector has been among the hardest hit by the coronavirus pandemic. In Germany alone, it brings in 130 billion euros in revenue each year, according to a recent study commissioned by the I.G.V.W., an industry group there. Concert venues were among the first to shut down to slow the virus’s spread, and their futures remain uncertain.

Indoor performances have returned in Germany, but slowly, under rules that vary from state to state. Many venue operators and event organizers, however, argue that the limitations on crowd size and hygiene requirements imposed by authorities make it economically unviable for venues that aren’t subsidized by the state to restart operations. In the United States, health experts have said that arena concerts would likely not happen on a wide scale until a vaccine becomes available.

Leipzig is in the state of Saxony, where indoor events are allowed with up to 1,000 attendees — amid strict hygiene and distancing rules. But Philipp Franke, a manager of the arena hosting the study, said in a phone interview that this number was still too low for him to reopen. The attendance limit is scheduled to be raised in September, but Germany’s rising infection numbers have drawn increased scrutiny to the plan.

Mr. Franke hoped that the study’s results from would allow politicians to make informed decisions about resuming concerts and indoor sports. “Cultural events are socially important,” he added. “A society needs such events in order to find some fulfillment and an outlet.”

The study is being led by Dr. Stefan Moritz, the head of the clinical infectious diseases department at the university. In a phone interview, he said the experiment was a response to the fact there was not enough scientific literature available for policymakers about the dangers of events like the one on Saturday.

“We know the personal contacts at the concert are risky, but we don’t know where they happen,” he said. “Is it at the entrance? Is it at the bleachers?”

Dr. Moritz concluded that the best way to bring in reliable data would be to stage an actual concert. The arena in Leipzig agreed to help manage the logistics and recruited Mr. Bendzko. In an interview backstage on Saturday, he said he took part in the study because “it is better to do something active to move things along than to sit at home and wallow in insecurity.”

He had played some small concerts in recent months at drive-in theaters, he said, but they were not economically viable. “Applause doesn’t pay our rent,” he added.

To minimize the risk of infection, all volunteers were tested for the coronavirus in advance, and had their temperatures checked upon arrival. Outfitted with their tracking devices, masks and fluorescent disinfectant, they were then asked to simulate different concert scenarios over the course of 10 hours: one with no social distancing, another with moderate safety measures and a third with strict ones.

Each iteration included performances by Mr. Bendzko and a break, during which participants simulated trips to vendors for food and drinks and made bathroom visits. Using trackers, the staff monitored the number of times attendees came close to one another, and later used ultraviolet lamps to determine which surfaces were covered with the most fluorescent disinfectant by the end of the day.

Dr. Moritz said that the most intriguing finding likely would be related to aerosol spread. Scientists have recently confirmed that the virus can remain suspended in the air, possibly for hours in closed environments.

“It’s so weird what happens with these movements of air,” he said. “Things you wouldn’t expect.”

To simulate the spread of aerosols in the arena on Saturday, staff used a smoke machine to emit a cloud of fog into the rafters. It drifted upward before moving into a spiral shape and spreading toward the audience. The spread of particles in the space was modeled by Mr. Moritz’s team, who will compared it with data collected by carbon dioxide sensors during the study.

Dr. Moritz said that results from the study, which was sponsored by the states of Saxony and Saxony-Anhalt, were expected be ready in early October, and argued that the findings likely could be applied to similar events and venues around the world. He added that he had already been contacted by researchers in Australia, Belgium and Denmark who planned to carry out similar studies.

For many people in the audience, volunteering was worth it for the experience of finally going to a concert after months of deprivation.

Bianca Tenten, a 21-year-old student from Cologne, Germany, said that listening to music at home couldn’t replicate the sense of togetherness and the spontaneous encounters that she often experienced at live music events. She added that for concert organizers and artists, “there is a passion and a love there.”

And Stefanie Oehme, a 34-year-old teacher who traveled to Leipzig from Dresden, said that she had grown dispirited with people who have claimed that limitations on public life were here to stay.

“I think this is a sign of things moving back toward the old normal,” she said. “It makes it a bit more tangible.”

source: nytimes.com