Residual biological surrogate aerosol risk reduction during disrobing litter-bound manikin patients using two dry air treatments for cold regions.

OBJECTIVE Determine relative effectiveness of two dry air decontamination methods to reduce residual airborne surrogate biological agent on litter-bound manikin patients during disrobing.

DESIGN Fluorescent 1 µm polystyrene latex (PSL) spheres were applied as a biological agent surrogate to a litter-bound manikin dressed in cold weather outer gear (parka and snow pants) representing the contaminated patient. Two dry air personal decontamination treatments were compared to that involving no -decontamination.

SETTING Cold region mass casualty biological aerosol contamination event.

PARTICIPANTS A litter-bound manikin.

INTERVENTIONS Two treatments were applied independently; high-efficiency particulate air (HEPA) filtered vacuum, and air-knife decontamination were compared to that involving no decontamination. After contaminating the manikin, a treatment was applied and the manikin disrobed. The disrobing process created the highest risk of re-aerosolization of the PSL spheres surrogate biological agent which could be inhaled by the attending medical personnel or the patient.

MAIN OUTCOME MEASURES Aerosolized PSL sphere quantification was sampled in the breathing zone of medical personnel and analyzed with ultraviolet microscopy.

RESULTS Analysis of variance revealed that treatment means of log-transformed data differed -significantly (p < 0.001). Tukeys Honestly Significant Difference test revealed a significant difference only between air-knife decontamination and no decontamination (p < 0.05). The HEPA vacuum reduced airborne contamination by 71 percent compared to no decontamination (not significantly different), while the air-knife reduced it by 91 percent (significantly different), after background correction.

CONCLUSIONS Considering ease of use and significant significance, air-knife decontamination was superior to HEPA vacuum in reducing airborne inhalational risk to attending medical personnel when disrobing the manikin.