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The anti-Covid-19 rules have imposed new requirements on restaurants, classrooms and other public places in an attempt to respect the principle of social distancing and to separate people from each other by insulating plastic barriers.
The New York Times, citing scientists, says the plastic barriers that are supposed to protect against germs and viruses do not help reduce the spread of the Corona virus infection and give people a false sense of security.
Under normal conditions in shops, classrooms and offices, small airborne particles are dispersed by drafts and, depending on the ventilation system, are replaced with fresh air every every 15 to 30 minutes. But the construction of plastic barriers can alter the mechanism of air circulation in a room, disrupting normal ventilation and creating “dead zones”, where particles can accumulate in certain areas and become very concentrated.
A study published in June led by researchers at Johns Hopkins University in the United States showed that desk barriers in the classroom are associated with an increased risk of infection with the Corona virus.
In the Massachusetts School District, researchers found that glass partitions in the side walls of the main office were obstructing air flow.
A study of schools in Georgia also found that office barriers had less of an impact on the spread of the coronavirus than improvements in ventilation.
Before the outbreak, a study published in 2014 found that office divisions were among the factors that may have contributed to the transmission of tuberculosis in Australia.
Catherine Knox, professor of environmental engineering for buildings at the University of Leeds, said erecting barriers seems like a good idea but could have unintended consequences.
She added: “The effect is to block the larger particles, but the smaller air particles travel over the barriers and mix into the ambient air in about 5 minutes. This means that if people interact for more than a few minutes, they are likely to be exposed. to the virus regardless of the presence of barrier gestures. “.
Researchers say that plastic or glass barriers are likely to help in very specific situations, for example the bus driver is protected from the rest of the passengers by a barrier that extends from floor to ceiling, as well as the cashier. from the bank sitting behind a glass wall or a clerk checking in patients in a doctor’s office, they are partially protected from transmission.
“I think this could be a problem, especially in places like classrooms where people are present for longer periods of time,” Knox said.
“Too many barriers hamper airflow and create higher risks that are difficult to identify,” she said.
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