Noel Kirkpatrick of MNN points to a new studythat confirms they were right; as Supreme Court Justice Louis Brandeis noted, sunlight really is the best disinfectant. The researchers of the study, Daylight exposure modulates bacterial communities associated with household dust, built little model rooms with little model windows and then "inoculated them with dust collected from residential homes in Eugene, OR, USA." The windows were variously clear glass, UV blocking glass, UV transmitting glass, or a solid aluminum plate.

Lovell Health House, 1929
Lovell Health House, 1929 - The new study authors conclude that "architects and lighting professionals designing building facades and rooms with more or less access to daylight may play a role in influencing the microbial communities of indoor dust." Indeed, architects and lighting professionals have known this for years. In his first major book, Towards a New Architecture, Le Corbusier wrote that you should "teach your children that a house is only habitable when it is full of light and air, and when the floors and walls are clear." © Department of Special Collections, Charles E. Young Research Library, UCLA./Public Domain