Indoor Environment Center

Air Quality Laboratory

Aerosol Laboratory

The Aerosol Laboratory is directed by Dr. James Freihaut of the Department of Architectural Engineering. Research issues investigated in the lab are centered on:

  1. the aero-biological pathways of bio-contaminant aerosols - aero-allergens, vegetative and spore forms of bacteria and fungi, viruses, endotoxins and mycotoxins;
  2. techniques for the capture and de-activation of these potentially harmful aerosols by UV, UV+ oxidant, filter, UV + filter, UV + Filter + oxidant technologies;
  3. quantitative characterization of surface - to - air aersolization rates and steady state aerosol partitioning between airborne and surface settled states as characterized by the so-called re-suspension factor;
  4. estimating occupant exposure dosages due to re-suspension phenomena.

The AL is concerned with the inhalation exposure, aero-biological pathways of common indoor bio-contaminants that lead to respiratory distress diseases - such as protein allergens from insects, pests, and pets - which are present on so-called carrier particles. The laboratory also investigates re-suspension phenomena of more immediately pathogenic, bio-aerosol forms, such as bacterial and fungal spores, protein poisons such as ricin, that are delivered in carrier particles, and mycotoxins which are also carrier particle mediated. The underlying surface chemistry, morphology, size effects and electrostatic susceptibilities that lead to surface-to-air aerosolization, re-suspension, of these very different bioaerosol contaminants lead to different effects on re-suspension for similar reservoir disturbances. A unique controlled disturbance, re-suspension chamber is used to quantify the re-suspension characteristics of bio-contaminate particles as a function of surface vibration, aerodynamic swirl, and transient electrostatic field disturbances. Optical particle sizing, aerodynamic diameter based impactor particle sizing, and enzyme-linked immuno-assay (ELISA) techniques are utilized to characterize the bio-contaminant carrier particle sizes and contaminant concentrations (allergens, protein poisons, mycotoxins).

Deactivation properties of the varying bioaerosol types are also investigated and found to vary significantly with the specifics of the chemical functionality determining the occupant health effect. A calibrated UV reactor is utilized to determine the UV deactivation susceptibility of bio-contaminates to know irradiance levels of UV light (254 nm, 310nn, 365nm). Varying oxidation field strengths can also be established.