Abstract:
The Bacillus anthracis contamination of the Hart Senate Office Building on October 15th, 2001 highlighted the need for reliable detect-to-warn bioaerosol collection equipment. Most bacteria of concern have effective diameters of approximately 5 µm or less. Likewise, particles of 20 µm or more are of little concern because they tend to exceed the thoracic fraction of the human body. An ideal bioaerosol inlet should exhibit reasonably high aspiration efficiencies throughout the 1 µm to 10 µm range while excluding particles larger than 20 µm. This study evaluated a novel bioaerosol inlet by challenging it with 3 µm, 7µm, and 200 µm particles. Gravimetric analysis of the 3 µm and 7 µm particles revealed a combined efficiency of 82% (74% and 100% respectively) while tracer analysis of the 200 µm particles showed an efficiency of 5%. This analysis supports computational fluid dynamics modeling of the inlet as well as its designed intent.