Medicine: Surgical Air

In a routine month. Mount Sinai Hospital and Clinic in Los Angeles would expect one or two postoperative wound infections owing to contamination in surgery. But not one case has turned up in the last six months, and surgeons could feel the reason while they worked. Blowing gently down over them from the operating-room ceiling was a curtain of air that was 99.9% free of germs, including the deadly staph.

The air was made surgically pure by being pumped through a 7-ft. cube housing 72 small cylinders, each containing an ultraviolet arc. The cylinders were designed so that every passing air particle swirled within 3 in. of a germ-killing arc light. Since ultraviolet rays kill germs more effectively at close range—their germicidal effect is proportionate to the square root of the distance—a microbe had only 1/256th as much chance of surviving a trip through the cylinders as it would have under an ultraviolet lamp hanging 4 ft. above the operating table.

The air washer, called the Aseptic Air System, is relatively inexpensive. Its inventors, a physicist and a well-to-do gadgeteer, can equip the average 1,000-sq.-ft. operating room for as little as $1,500.