Health risks from vaporizing blood.

Federal law requires that employers protect health care workers from the AIDS virus and other potentially infectious agents by employing "universal precautions" to limit exposure to blood and other bodily fluids. This generally means wearing gloves or masks where blood may be present. But surgery in which tissue is burned off doesn't automatically trigger these mandatory precautions, according to Douglas E. Ott, a physician at the Mercer University school of engineering in Macon, Ga. That oversight may put surgical crews at risk, he argued last month in Atlanta at the annual meeting of the American Association for the Advancement of Science.

The smoke emitted during laser cauterization can travel 40 yards or more, he notes, prompting complaints from surgical crews several rooms away. And while such workers may complain about tearing eyes or respiratory irritation, Ott worries even more about infectious agents that may have hitched a ride into nasal passages along with that smoke.

As lasers and other cauterizing devices vaporize targeted tissue, some of the surrounding, at least partially unburned cells will be freed to waft away with the smoke, Ott notes. Though hospitals provide minivacuums to suck up the irritating combustion products, he says, surgical staffs don't use these devices as religiously or carefully as they should--primarily because they consider smoke no more than a nuisance. In fact, he notes, one 1991 study by researchers at the State University of New York in Syracuse cultured HIV, the AIDS-causing virus, from smoke emitted during laser cauterization of infected tissue.

Ott argues that the Occupational Safety and Health Administration should explicitly target for mandatory engineering controls any aerosols produced by the combustion of blood. OSHA should require smoke evacuation when open-air tissue cauterization is under way and consider recommending respirators for surgical crews--because masks offer ineffective protection against aerosols. He also recommends that hospitals install ultraviolet lighting, air ionizers, and other antimicrobial technologies.

As it is performed today, Ott told Science News, cauterizing surgery contributes substantially to making "the operating room the most polluted part of the hospital."