Why is the safe social distance set at more than 1 meter? What are the other considerations? Peng Yanqiong, deputy director of Public Health Department of Wuhan first hospital, answered: This is mainly due to the consideration of preventing respiratory infectious diseases, including COVID-19.
One meter social distancing to reduce the risk of infection
Peng Yanqiong said novel coronavirus pneumonia, tuberculosis and new crown pneumonia will spread through the air. If an infected person coughs, sneezes or discharges secretions, he or she may spray droplets containing virus; after inhaling droplets containing virus, the susceptible person may easily cause infection. Therefore, the closer the distance between people, the greater the risk of infection.
Current studies show that most of the droplets fall to the ground within a distance of 0.8 m ~ 1 m under the action of gravity. In addition, the risk of infection becomes smaller when the distance is more than 1.8 meters in non closed scenes. In outdoor with fresh air,1meter is safe. But if wind is strong, it may ask 1.8m to 2m.
Novel coronavirus pneumonia and public signs are recommended to prevent new crown pneumonia. Citizens should wear masks, reduce aggregation and keep safe distance in public places.
What is the safe distance? The three versions of more than 1 meter, 1.5 meter and 1.8 meter are all reasonable, depending on wind, new air quality, environment. Therefore there is no fixed value for it, and no system can promise everyone will always follow this safe distancing. Currently the best solution is to control footfall occupancy for public area, library, station, cinema，malls and super market by video people counter. Reamol video people counters will be placed at each entrance, all in-come and left passengers will be counting correctly. The TV monitor will show the Live Occupancy Status and Vacancy Numbers with alert words and signs. Alarm lighting can be connected to people counters to stop active customers in the building over the safe distancing level.