For people in cities like New York, going back to work during a pandemic can mean taking multiple elevator trips a day to and from their office spaces , but without established safety measures, elevators could become hot spots of spread from COVID-19, the data suggests.
COVID-19 can spread when infected people cough and vomit large respiratory droplets, either contaminating people directly or depositing the virus on nearby surfaces. The virus can also spread through smaller particles. called sprays, expelled when people breathe, speak or sing. Various superspreader events, where many people contracted the virus from an infected individual, suggest that crowded interior spaces with poor ventilation pose high risks of disease transmission; Elevators, being enclosed in metal boxes with frequently touched buttons, carry similar risks of spread, The New York Times reported.
This week, the US Centers for Disease Control and Prevention (CDC) plans to publish an official guide on how to safely operate elevators while the coronavirus is still circulating, according to the Times. Recommended measures will include: requiring all runners to wear masks; limit the number of riders; marking paths on the floor to direct people in and out; and put up posters to remind people not to “talk unless it’s necessary,” Nancy Clark Burton, CDC senior industrial hygienist, told the Times.
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“They should put big signs on the elevator: ‘Don’t talk,'” Richard Corsi, dean of engineering and computer science at Portland State University and a specialist in indoor air quality, told the Times. In April, Corsi developed a computer model to simulate how an infected person could contaminate an elevator while traveling between 10 floors, and how much virus could remain in the elevator after the driver exits. He shared the results on Twitter, and discussed the research in a related New York Times report, published in May.
“Here is a high uncertainty, but this unique hypothetical scenario suggests that the air in the elevator car may remain infectious for travel beyond the infector outlet, “he wrote in a tweet.
Taking into account standard elevator speeds, ventilation systems, and door closing times, the model simulated the amount of virus that would be expelled from an unmasked person who coughed and spoke on a cell phone while traveling. A single cough can expel several thousand to several hundred thousand viral particles, by context, Corsi told the Times. He calculated that talking on the phone would expel about a fiftieth number of viral particles per second compared to a mild cough, although that number can vary widely in real life, he noted in a tweet.
Once contaminated, the air inside the elevator mixes with the outside air when the elevator doors open and close, and the infected passenger exits. The model estimated that when a second passenger boards the elevator, they would be exposed to approximately 25% of the viral particles expelled by the infected driver.
This percentage would vary depending on the elevator and air pressure within a given building, and yet the persistent viral particles may not be abundant enough to infect the second pilot, Corsi said. Scientists have not determined how many viral particles a person must inhale to become infected, so the probability of trapping COVID-19 from viral fragments floating in an elevator cannot be accurately calculated, he noted. “The main intention of the exercise was to show that a certain level of virus can be maintained in the air beyond an infected person using the elevator,” said Corsi. “I don’t know if the dose in an elevator will be high enough to pose a significant risk.”
While the risk of traveling by elevator after an infected person has come out unclear, riding with an infected person definitely presents a significant risk of transmission, especially compared to spending time near that person in a less confined space, Corsi said. “Stand as far as you can diagonally [the] the elevator would be fine, and don’t talk, “he said.
In most states, the standard elevator must be at least 4 feet 3 inches deep and 5 feet 8 inches wide (130 centimeters by 173 cm), according to the Stanley Elevator Company, The New York Times reported. These dimensions make keeping the distance between you and others very difficult. “I can’t give you six feet in an elevator, you should have someone on the roof and someone on the floor,” Andrew Hardy, chief operating officer of JEMB Realty, a private company that owns and operates residences and commercial properties, told The New York Times.
A new high-rise building that JEMB Realty is building in New York will include contactless elevator technology, which allows passengers to call their elevator using a card or key fob, Hardy said. In addition to non-contact technology, the new elevators could include improved air ventilation, antimicrobial materials, and the use of ultraviolet light to disinfect surfaces, Lee Gray, an elevator historian at the University of North Carolina at Charlotte and a correspondent, told the Times from Elevator World Magazine. .
Originally published in Live Science.
