1877

Year scientists observed that sunlight prevented the growth of microorganisms, with blue, violet and ultraviolet rays having the greatest bactericidal effects

0.24

Percentage of postoperative wounds that became infected after the operating room at Duke University Hospital was treated with uv germicidal irradiation in 1936—down from 11.62% before the treatment

200-300

Wavelength in nanometers (one-billionth of a meter) of electromagnetic radiation necessary to destroy bacteria, viruses and fungi

1903

Year the Nobel Prize for Medicine was awarded to Niels Finsen for his use of UV light in treating tuberculosis of the skin, which causes lesions on the face and neck

40

Percentage of samples in one study from toilets at a hospital in Winnipeg that showed Clostridium difficile bacteria, which cause severe stomach illness, even after the toilets had been thoroughly wiped down

99.8

Percent reduction in C. difficile spores within 50 minutes of treatment by a UV-C (short wave) radiation device, in one study

4

Height, in feet, of “Rosie,” a UV-C room disinfection robot developed by Xenex Healthcare Services, nicknamed for the robot housekeeper on the tv show The Jetsons

82,000

Cost, in dollars, of Xenex’s UV-C robot, which is used in about two dozen U.S. hospitals