Students disinfecting screens. yunhap news
Transparent plastic screens erected in restaurants and classrooms to prevent mass infection of the new coronavirus infection (COVID-19) are effective only in limited circumstances, and concerns have been raised that it may have the opposite effect in some situations.
The New York Times (NYT) reported on the 19th (local time) an expert opinion that “a transparent screen does not help prevent COVID-19 by blocking the airflow, but it can also make the situation worse by making you unattended.”
Experts explain that in small spaces such as shops, classrooms, and offices, particles released when people breathe are carried by air currents and are replaced by fresh air approximately every 15 to 30 minutes. However, if a plastic screen is installed, normal ventilation will not be possible, and the risk of infection may be increased by concentrating virus particles.
Although it is possible to directly block saliva with a screen, viruses often spread as an invisible aerosol (solid or liquid particles in the atmosphere), so blocking saliva alone is often insufficient. “If there are blinds in the classroom, it will interfere with proper ventilation,” said Lindsay Ma, a professor at Virginia Tech University in the US.
A research team led by scientists at Johns Hopkins University in the United States even came up with a study showing that installing screens increases the number of COVID-19 infections. In a study published in June this year, the research team argued that curtains on desks in classrooms were associated with an increased risk of contracting COVID-19. Their results showed that in a school district in Massachusetts, screens were found to obstruct airflow, and in schools in Georgia, desk screens had little effect on the spread of COVID-19. According to the results of this study, ventilation or wearing a mask was more effective than installing a screen to prevent COVID-19.
The results of the study in the UK were similar. British researchers tested how effective the shields were when people spoke or coughed under different ventilation conditions, and found that the shields were effective at blocking particles from coughing, but not trapping particles generated during the speech process. Catherine Knox, a professor of architectural and environmental engineering at the University of Leeds in the UK, said: did.
The New York Times summarized the results of these studies and said, “Most studies say that screens will be helpful in quarantine in certain situations.” Screening can be effective,” he concluded.
By Shin Hye-yeon, staff reporter shin.hyeyeon@joongang.co.kr
