Researchers in Peru found that opening hospital windows worked better than modern ventilation systems at preventing the spread of airborne infections.
"Opening windows and doors maximizes natural ventilation so that the risk of airborne contagion is much lower than with costly, maintenance-requiring mechanical ventilation systems," wrote Rod Escombe of Imperial College London and colleagues in their report. "Old-fashioned clinical areas with high ceilings and large windows provide greatest protection. Natural ventilation costs little and is maintenance free."
The researchers were particularly concerned with limiting the spread of tuberculosis. My grandmother, as a teenage girl, went to work in TB sanatoriums in Saranac Lake, NY - at that time, people took "the cure" at mountain locations, whether in Switzerland or New York or North Carolina, where the air was clear and cold. They would sit outside, wrapped in blankets, to let the sun and air heal their lungs.
It takes more than a winter morning to cure TB, but it also doesn't hurt to let air, and sun, onto bodies built for them. We spend too much time in closed rooms, in "sick" buildings and smoggy cities.
Mentally, the same holds true. Closed rooms, negative ventilation, a lack of light and air - or closed minds, negative thoughts, a lack of information and awareness. Both can lead to contagion and illness.