Determination of Laser Generated Air Contaminant Emission Rates in a Simulated Surgical Procedure

The Occupational Safety and Health Administration estimates that half of a million surgical staff are exposed to laser smoke each year. The type and intensity of exposure is dependent in part on the way a laser is used during surgery. The purpose of this study was to estimate emission rates of the gas phase constituents of laser generated air contaminants using a validated emission chamber methodology while differentiating the effects of the laser operational parameters of power, pulse-repetition frequency, and beam diameter on the estimated emission rates and ultimately estimating a range of plausible occupational exposures. Two medical lasers (Holmium and CO2) were set at varying operational parameters in a simulated laser surgery on porcine skin in a validated emission chamber. The plume was sampled for seven chemical agents (including volatile organic compounds, formaldehyde, hydrogen cyanide, carbon dioxide, carbon monoxide) selected to represent tissue combustion by-products. The effect of each operational parameter on emission rates was determined using a fractional factorial design coupled with a sequential screening process that evaluated the parameters for their influence on emission rates after each round of data collection. Measured concentrations of each agent were either below the limit of detection or well below occupational exposure guidelines. Our preliminary results under these experimental conditions suggest that only beam diameter was a statistically influential parameter to estimated emission rates using the Holmium laser, while none of the operational parameters examined influenced emission rates using the CO2 laser. Estimated exposures were three orders of magnitude below occupational exposure limits. This exploratory study identified operational parameters that influence emission of laser generated air contaminants, and established a laboratory simulation protocol that may be used in future investigations to characterize the influence of these and additional parameters that may affect contaminant generation for emerging technologies and clinical applications. In the future, this protocol will be refined to distinguish influential operational parameters and develop an effects model that can be used to estimate a variety of occupational exposures.