To the editor:

COVID-19 appears to spread mostly via airborne transmission, and the best research suggests that sustained exposure to other people in poorly ventilated indoor spaces poses a risk of infection. Disturbingly, there are now many documented cases of indoor transmission at supposedly “safe” social distances of 10 feet or more — in restaurants, in offices and even at choir rehearsals.

In contrast, outdoor encounters are much safer. The unlimited air volume quickly dilutes airborne viral particles, and solar UV, warm temperatures and higher humidity also help to neutralize the virus. Of the millions of global COVID cases thus far, instances of outdoor transmission appear to be rare.

These facts have profound implications for the safe reopening of downtown restaurants, bars and retail establishments in our beloved city. Specifically, we believe it’s time to urge downtown establishments to shift their customer operations outside, as they do during the annual Summer Sidewalk Sale. In fact, if Massachusetts Street were closed to vehicle traffic until the end of the pandemic, eateries would have the space to set up abundant outdoor seating (with tables set 6 feet apart as an added precaution), and retailers would have ample room to display their wares. Downtown could once again be abuzz with people and activity and commerce — and could do so at a tolerably low level of risk.

Accordingly, we encourage our mayor, City Commission and other civic leaders to consider quickly enacting the needed steps to help safely revitalize our downtown by shifting the locus of activity outside during this time of unprecedented challenge.

Steve Ilardi and Lee Reussner, M.D.

Lawrence