According to a new study, the often-used guideline of staying six feet apart from others does little to limit the potential exposure to COVID-19 in indoor spaces.
According to researchers at the Massachusetts Institute of Technology (MIT), the widely used guideline is based on an outdated understanding of how viruses move in enclosed spaces.
The study suggests that the amount of time spent inside with other people, specifically those infected with the coronavirus, matters far more.
Other factors that are more important to limiting potential viral transmission include the number of people inside a specific place, whether they’re wearing masks, and the facility’s indoor ventilation systems.
The MIT study says six feet distancing can “substantially reduce the risk” of large-drop transmission through couching and sneezing but says airborne transmission is known “to span a considerable range of scales,” varying from fractions of a micron to mere millimetres.
The six-foot physical distancing practice became commonplace last spring when early studies of the spread of COVID-19 suggested the virus was transmitted by heavier droplets that were transmitted through sneezing or coughing.
The MIT study says lighter aerosol droplets can stay suspended in the air for longer and travel further. In some cases, according to the study, the risk of potential exposure can be the same, from six feet to 60 feet.
The study’s authors found that wearing a face mask has been more effective than either lockdowns or physical distancing in controlling the spread of COVID-19.
The MIT researchers built an online tool designed to help people calculate how their formula can estimate the risk for different indoor rooms based on sizes, occupancy levels, ventilation systems, and mask-wearing behaviours.