Sampling of Airborne Viable Particles - A Comparative Study of Common Instruments

Microbial monitoring of the indoor environment can be performed in several ways and with the aid of different techniques. Knowing the limitations of the chosen system is of vital importance for the correct evaluation and interpretation of the results. The number of Colony Forming Units (CFU) detected by one method can not be directly compared with results from another method. The paper presents an evaluation of commonly used instruments for the collection and counting of airborne viable particles. Physical properties are discussed, such as impaction velocity and efficiency of particle collection. Microbiological tests have been performed in a controlled environment in order to achieve comparative results of commercially available instruments.