Presenter Bio: Mark Hernandez
Mark Hernandez, PhD, PE Professor of Environmental Engineering, University of Colorado at Boulder Dr. Hernandez attained all his degrees from the College of Engineering at University of California at Berkeley. He is a registered professional engineer, and an expert on the characterization and control of bioaerosols – both indoors and out. The focus of much of his work leverages forensic science for wide area surveillance and aerosol disinfection on large indoor scales. Dr. Hernandez holds several patents and has authored over 100 archival publications. He has recently on served four US National Academy of Science committees, focusing on the microbiology of the built environment, bioterrorism research and disease transfer in urban settings.
Conventional industrial hygiene assessments often survey indoor spaces under conditions where occupant activity and particle resuspension potential are not near their maxima. Such assessment practices have the potential to underestimate the respirable particle loads occupants actually experience. In response, some in the IAQ community have suggested systematically perturbing indoor environments in a way that mimics peak occupant activity for the express purpose of conservatively assessing the resuspension potential of airborne particulate matter – biological or otherwise. Since microbiological materials (bioaerosols) and inorganic materials (dirt) have different resuspension potential, purposeful perturbation of the indoor environment likely yields different particle exposure profiles than those obtained under quiescent conditions, not only with regard to total particle loads, but the fraction thereof that are of biological origins (e.g., mold). This presentation will revisit the history of perturbation practices, the recent deployment of new perturbation practices for specific site assessments (residential, office and educational) in a context for introducing a new generation of portable monitoring technologies that can characterize airborne biological materials in near real time. The presentation will close with a discussion of standardizing specific energy delivery paradigms (turbulence) for different built environment scenarios and the advantages of obtaining data from both quiescent and perturbed conditions.