Connecticut's trains got it (mostly) right

From the country estates to which the wealthy fled to escape the plague-infested cities of medieval Europe, to the tuberculosis sanitoriums of the early twentieth century, fresh air has long been endorsed as an aid against deadly respiratory illnesses.

Now, in the time of COVID-19, that endorsement still holds. “Even with masks on, when you are indoors, opening windows can make a difference,” says Krystal Pollitt, assistant professor of epidemiology and chemical engineering.

But opening windows is not always an option. In a report commissioned by the Connecticut Department of Transportation (DOT) to assess best practices for reducing the risk of virus transmission on commuter trains, Pollitt and her team reiterated the familiar behavioral advice: wear masks, keep physically distant, practice good hand hygiene.

At the same time, they found that the separate HVAC systems installed in each DOT railcar do a good job of filtering potentially infectious aerosols: they exchange railcar air with outdoor air every six minutes. The researchers did recommend that the state upgrade the filters, from a type that removes 50 percent of aerosols to one that removes 80 percent.