THE POSSIBILITY OF REAL-TIME MEASUREMENT FOR AIRBORNE BACTERIA CONCENTRATION IN INDOOR ENVIRONMENT

Traditional method for measuring airborne bacterium is based on two procedures called sampling and incubation. Sampling normally involves drawing a sampler from an air stream or room by means of instruments based on impaction, liquid impingement and filtration. Incubation of agar plates typically requires several days. Though the traditional methods can identify the species of microorganisms, they can't obtain any information about suspended viable particles in real time.The technology for real time detection of the presence of suspended viable particles was developed. In order to verify the performance of a new type measurement IMD (Instantaneous Microbial Detection, Bio Vigilant, Inc.), which is used to measure the concentrations of suspended particles with different size distribution based on optical technology and can simultaneously determine whether each particle is inert or biologic in real time. Not only laboratory tests by using latex particles (as a substitute for inert particles) and fluorescence particles (as a substitute for biologic particles) were conducted, but measurements on airborne microbes in six hospital waiting rooms, one office, and one residence were conducted by using an IMD and MG sampler (culture-based, slit type, Mattson-Garvin Inc.) in parallel.Significant correlations between suspended bacterial concentration and biological particle concentration were obtained. The measurement results pointed out that the IMD can measure the fluctuation patterns of suspended bacterial particles in field environments in real time.