NIOSH finds toxin levels low from surgical smoke

Particles may cause irritation for OR nurses

An investigation of surgical smoke at three hospitals by the National Institute for Occupational Safety and Health (NIOSH) failed to find levels of toxic substances above the currently recommended limits.

One of the three hospitals recorded levels of particulate matter that may lead to closer examination of ventilation systems in the day surgery unit. However, none of the levels of compounds or particulates detected exceeded permissible exposure limits (PEL) set by the Occupational Safety and Health Administration (OSHA) or recommended exposure limits set by NIOSH.

"None of what we found would have surpassed the eight-hour level that’s represented by the PEL, even if [the operating room (OR) staff] had been spending back-to-back hours within an [OR] for any of the procedures we found," says Bradley King, MPH, an industrial hygienist in NIOSH’s Hazard Evaluation and Technical Assistance branch.

Although the levels would not be characterized as a health hazard based on current limits, they still could cause irritation in some individuals, King notes. The industrial hygiene sampling was part of a preliminary report. Results of medical surveys and ventilation analysis will be included with the final health hazard report to be released later this summer.

NIOSH researchers are conducting health hazard evaluations at Carolinas Medical Center in Charlotte, NC; Morton Plant Hospital in Dunedin, FL; and Inova Fairfax Hospital in Falls Church, VA. In two cases, the request for a health hazard evaluation came from employees. At Morton Plant, management officials had asked for NIOSH assistance.

The Association of periOperative Registered Nurses (AORN) in Denver asked OR nurses to contact NIOSH with their concerns about the smoke, and the current investigation stems from those complaints.

A spokeswoman for AORN declined to comment on the surgical smoke data, noting that the findings were preliminary and that other information would be included in the final report.

The evaluations may produce the most detailed information yet about the actual exposure of OR personnel to dangerous compounds in smoke from electrocautery. Surgeons, nurses, OR technicians, and anesthesiologists wore sampling devices. NIOSH researchers also surveyed OR staff for symptoms that might be associated with exposure to surgical smoke, and they examined the hospitals’ ventilation systems.

"We were looking for compounds that previously had been detected in surgical smoke," King says.

When human tissue burns, either in electrosurgery or laser procedures, cells burst and tiny particles become airborne in a noxious plume. OR nurses have reported suffering from nausea, abdominal cramps, and respiratory problems after hours of breathing the surgical smoke.

In 1998, NIOSH issued a "hazard alert" recommending the evacuation of surgical smoke. It stated that: "Research studies have confirmed that this smoke plume can contain toxic gases and vapors such as benzene, hydrogen cyanide, and formaldehyde, bioaerosols, dead and live cellular material (including blood fragments), and viruses. At high concentrations, the smoke causes ocular and upper respiratory tract irritation in health care personnel, and creates visual problems for the surgeon. The smoke has unpleasant odors and has been shown to have mutagenic potential."1

Still, research on the smoke and its health effects has been limited, and the information on surgical smoke has been considered largely anecdotal. In July 2000, OSHA shelved a "technical information bulletin" on surgical smoke, saying the agency needed more evidence of a link between the smoke and ailments that afflict OR staff.

In monitoring, NIOSH found formaldehyde, acetaldehyde, and toluene. However, King notes that those compounds could have come from other sources in the OR. He adds that levels of those compounds were found even in surgical procedures in which an electrocautery device
was not used.

"Another concern was particulate production in the smoke," King says. "We used some direct reading instruments that produced information and recorded it minute by minute to see if there were any peaks of particles in the room that could be dangerous, and what was the size of the particulates."

In two hospitals, the smallest particles — those 7.5 µ or smaller that could lodge in the deepest regions of the respiratory tract — were not present at a substantial level, and overall peaks of particulate matter didn’t necessarily correlate with the use of the electrocautery device.

In one hospital, a day surgery suite recorded larger background concentrations of particulate matter. One mastectomy case produced a spike in particulate matter immediately after the device was used; a comparable mastectomy case in which the surgeon preferred using a scalpel showed no appreciable particulate matter.

Those findings will be considered in the analysis of ventilation, King notes.

Nurses welcome NIOSH’s help

The health hazard evaluations provide information that hasn’t previously been available about real-life exposures. "We felt it was important to get personal samples," King says.

"That gives us an indication of what the personal exposures are. There hadn’t been a lot of that [research] done in the past. The compounds that have been reported to be produced could be potentially harmful. But we didn’t know what the levels of exposures might be," he says.

Nursing advocates were pleased when NIOSH responded to the complaints and began the evaluations. "This is long overdue," says Kay Ball, RN, MSA, CNOR, FAAN, a perioperative educator and consultant based in Columbus, OH. "Nurses have to breathe this day in and day out, and nothing is being done."

Ultimately, the nurses want OSHA to require hospitals to evacuate the smoke. The NIOSH research could be a step toward future OSHA action. "Every time surgical smoke is created, we [should] evacuate it," Ball says. "We’ve been looking for OSHA to get involved for years."

King notes that the health hazard evaluations won’t be the definitive information on surgical smoke. "We’re probably not answering every question that can be asked about surgical smoke," he says.

Reference

1. National Institute for Occupational Safety and Health. Control of Smoke from Laser/Electric Surgical Procedures. DHHS (NIOSH) Publication No. 96-128. Washington, DC; 1998. Web site: www.cdc.gov/niosh/hc11.html.