Overview. Objective. Purpose. Hypothesis. Procedure

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1 Detection of Indoor borne Fungal Contamination Through Examination of Building Heating, Ventilating and Conditioning (HVAC) s Hernando Perez, PhD, MPH Assistant Professor Department of Environmental and Occupational Health Drexel University School of Public Health Philadelphia, PA hrp@drexel.edu eil Zimmerman, PhD, PE, CIH Associate Professor Purdue University School of Health Sciences West Lafayette, I Overview Purpose Objectives Hypothesis Procedure/Methods Results Conclusions Limitations Purpose This phase To assess viable particle from building HVAC filters as a means of evaluating viable airborne fungal levels Overall research To determine whether or not HVAC filter examination can be used as a means of evaluating relative levels of indoor airborne fungal contamination Objective To compare fungal concentrations detected on building HVAC filters with the results of repeated 6 impactor sample results Hypothesis Viable particle results from building HVAC filters are significantly associated with the results of repeated single stage viable impactor sampling performed while the filter is in service Procedure Conduct regular air sampling with Andersen 6 viable impactor while filters in place Quantify viable particles on filters and compare results to air sampling

2 Quantification Procedure** s in Shaking Solution Square filter samples ( in ) cut out manually Samples placed in volume of.9% sterile saline in Erlenmeyer flask Orbital shaker to 6 minutes. ml plated in triplicate onto potato dextrose agar Incubated at o C for 96 hours Colonies (CFU) Counted ** Moritz, M. and H. Martiny:International Journal of Hygiene and Environmental Medicine [Zentralblatt Fur Hygiene Und Umweltmedizin]:99: 6 (997). What Are We Evaluating? Is there a significant relationship between filter results (CFU/m ) and air sampling results taken while filter is in service? Regression Which method better differentiates viable fungal concentrations in separate areas? AOVA Regression Two Procedures Strength of association between filter (dependent) value and each air sampling concentration (independent) (multiple X for each ) Strength of association between filter and a single average air concentration value ( X for each ) Low Volume Systems Outpatient Healthcare facility HVAC system decentralized with different zones units and the area they supply involved in research Single Family Homes High Volume Systems Administrative office building One centralized HVAC system with one filter bank Academic building containing offices, labs and classrooms Multiple high volume ventilation systems in building. Two units each serving half of two floors involved in research

3 Outpatient Facility s 6 x x or x x filter loading periods with air samples taken X per week ( weeks total) 7 week, week, week Roof leaks Areas and Complaints Areas, and Expected order (decreasing fungal levels), (,),, Summary of Results Quantification Period / Location sampling mean concentration (CFU/m ) Mean of Log Transformed s mean detected concentration (CFU/m) sample/ filter Coefficient of Variation (σ/mean) 7 week / area week / area week / area week / area week / area week / area week / area week / area week / area week / area week / area week / area week / area week / area week / area Outpatient Facility Regression Regression Significant (/) p-value R Log Transformed One Week vs Log One Week s one week filter vs one week air samples two week filter vs two week air samples seven week filter vs seven week air samples Untransformed one week filter vs one week air sampling average two week filter vs two week air sampling average seven week filter vs seven week air sampling average =.8X -.6 p=., R =.... log CFU/m (air sample) One Week vs One Week Two Week vs Log Two Week s 8 CFU/m (filter)... =.6X+. p=.7, R = =.7X -. p=., R = CFU/m (air sample)... Log CFU/m (air sample)

4 Two Week vs Two Week =.X -.6 p=.7, R =.78 Outpatient AOVA Groupings Sample week 7 week filter 7 week air week filter Significant (/) P-value <. Order (descending),,,,,,,,,,,,,,,, Grouping A: AB:,, B: A:, AB:, B: A:,,,, A: B: BC:, C: week air.7,,,, A:,,,, week filter.,,,, A: B:,,, CFU/m (air sample) week air.9,,,, A:,,,, Homes Homes Summary Results single family homes from Midwestern city Ducted ventilation systems operated continuously during data collection Home owners had minor IAQ concerns Home owners had no IAQ concerns Home owners had serious IAQ concerns Expecting descending order,, over days Filtrete 6 x x Micro Allergen Extra Reduction (M, St. Paul, M) Home Quantification (CFU/m ) First Floor (CFU/m ) Mean of Log Transformed First Floor.7..6 Basement (CFU/m ) Mean of Log Transformed Basement...8 Outdoor (CFU/m ) First Floor Sample / filter Coefficient of Variation (σ/mean) Home Regression Significant (/) p-value R Regression Log Transformed vs Basement..9 Home vs Log First Floor s vs First Floor.. vs Outside.6. Untransformed =.X p=., R =. vs Basement vs First Floor vs Outside Log CFU/m (air sample)

5 Home vs First Floor Home vs Log Basement s =.X + 7. p=.8, R =.9 =.6X -. P=., R = CFU/m (air sample) LogCFU/m (air sample) Home vs Basement Three Home AOVA Groupings Sample Significant (/) p-value Order (descending) Grouping =.7X +.9 p=., R =.76 Basement First Floor Outdoor <..9.6,,,,,, A: B:, A:, B: A:,, Quantfication <.,, A: B: C: CFU/m (air sample) One Week Outpatient and First Floor Home Regression (Log ) One Week Outpatient and First Floor Home Regression () =.8X p<., R =.6 =.7X +. p<., R = Log CFU/m (air sample) 6 8 CFU/m (air sample)

6 Combined Administrative and Research Facility Results Administrative and Research Facility Combined Regression (Log ) Bank (cfu/m ) Mean of Log Transformed s (cfu/m ) sample / filter research facility west research facility east =.7X +.9 p=., R =. Administrative Log CFU/m (air sample) Administrative and Research Facility Combined Regression () Conclusions.... =.8X -.6 p=., R =.88 HVAC viable fungal particle filter is a method that has potential for future use in IAQ as a tool to assess relative levels of airborne fungal contamination A positive statistically significant relationship exists between filter results and air sampling results taken during filter service Viable particle recovery from and of HVAC filters merits further research and development CFU/m (air sample) Limitations Wide variation in types of HVAC systems and filters. Research applicable to a very focused subset. collection efficiency Relatively short loading periods Acknowledgements eil Zimmerman, PhD, PE, CIH Herman Cember, PhD Frank Rosenthal, PhD, CIH Jin Rong Xu, PhD Lila Albin, PhD, Senior Industrial Hygienist, Purdue University This research study was supported by the IOSH Pilot Research Training Program of the University of Cincinnati Education and Research Center Grant #T/CCT 6