Methodology to Perform Clean Air Delivery Rate Type Determinations with Microbiological Aerosols

Foarde, Karin; Myers, Eric A.; Hanley, James; Ensor, David; Roessler, Peter F.

doi:10.1080/027868299304813

Cited by 2 publications

(3 citation statements)

References 5 publications

(5 reference statements)

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“…In the present study, four sample media were evaluated. PBS, nutrient broth, and deionized water are frequently used to collect artificially produced phage aerosol, while SM buffer has rarely been used (15,26,50,59,61). The results proved that SM buffer and nutrient broth are excellent in collecting phage D29.…”

Section: Discussionmentioning

confidence: 94%

Impact of Relative Humidity and Collection Media on Mycobacteriophage D29 Aerosol

Liu

Wen

et al. 2012

Appl Environ Microbiol

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This study was conducted to evaluate the effect of aerosol generation, methods of sampling, storage conditions, and relative humidity on the culturability of the mycobacteriophage D29. The lytic phage D29 can kill Mycobacterium tuberculosis, and the phage aerosol can be treated as a potential tool for tuberculosis treatment. The culturability of D29 was tested using a test chamber designed for the bioaerosols research against three spray liquids (deionized water, phosphate-buffered saline [PBS], and normal saline), four collection media (suspension medium [SM], nutrient broth, PBS, and deionized water), two sampling systems (the all-glass impinger AGI-30 and the Biosampler) and across a range of humidities (20 to 90%). The effect of storage conditions on the culturability of collected sample was also evaluated for the AGI-30 impinger. The results proved that viable phage D29 particles generated by deionized water were approximately 30-and 300-fold higher than PBS and normal saline, respectively. As collection media, SM buffer and nutrient broth were observed to yield a higher number of plaques compared to PBS and deionized water. No difference was observed in collection efficiency between AGI-30 and Biosampler with two detection methods (culture-based technique and real-time PCR). The culturability of collected D29 in SM buffer or nutrient broth can be maintained up to 12 h irrespective of storage temperature. Relative humidity was found to strongly influence airborne D29 culturability which is 2-to 20-fold higher in low humidity (25%) than medium (55%) or high (85%) humidity. This research will help identify the optimal means for the application of D29 aerosol in animal inhalation experiments.

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Section: Discussionmentioning

confidence: 94%

Impact of Relative Humidity and Collection Media on Mycobacteriophage D29 Aerosol

Liu

Wen

et al. 2012

Appl Environ Microbiol

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“…(37) For this study a modification of the AHAM test method was used to determine the CADR for microbiological aerosols, termed CADRm. (17) A completely mixed room model was used to estimate the removal rate of the air cleaning technologies as previously described. (16,20) The removal/inactivation rate (R) is defined here as the CADRm for airborne bacteria cells or fungal spores associated with the operation of the air cleaner (or the upperroom air UVGI system) divided by the room volume in which it has been applied.…”

Section: Completely Mixed Room Modelmentioning

confidence: 99%

“…(10)(11)(12) Studies have been performed evaluating the performance of upper-room air UVGI for inactivating bioaerosols. (11)(12)(13)(14)(15)(16) In-room air cleaning has been used to effectively reduce indoor particle concentrations in many settings (17)(18)(19)(20)(21)(22)(23) and can be achieved by operating devices that circulate room air through fiber filter medium or other technologies designed to collect particles from the incoming air. These devices can be stand-alone or mounted on the ceiling or walls.…”

Section: Introductionmentioning

confidence: 99%

UV Air Cleaners and Upper-Room Air Ultraviolet Germicidal Irradiation for Controlling Airborne Bacteria and Fungal Spores

Kujundzic

Matalkah

Howard

et al. 2006

Journal of Occupational and Environmental Hygiene

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In-room air cleaners (ACs) and upper-room air ultraviolet germicidal irradiation (UVGI) are engineering control technologies that can help reduce the concentrations of airborne bacteria and fungal spores in the indoor environment. This study investigated six different types of ACs and quantified their ability to remove and/or inactivate airborne bacteria and fungal spores. Four of the air cleaners incorporated UV lamp(s) into their flow path. In addition, the efficacy of combining ACs with upper-room air UVGI was investigated. With the ventilation system providing zero or six air changes per hour, the air cleaners were tested separately or with the upper-room air UVGI system in operation in an 87-m3 test room. Active bacteria cells and fungal spores were aerosolized into the room such that their numbers and physiologic state were comparable both with and without air cleaning and upper-room air UVGI. In addition, the disinfection performance of a UV-C lamp internal to one of the ACs was evaluated by estimating the percentage of airborne bacteria cells and fungal spores captured on the air filter medium surface that were inactivated with UV exposure. Average airborne microbial clean air delivery rates (CADRm) varied between 26-981 m3 hr-1 depending on the AC, and between 1480-2370 m3 hr-1, when using air cleaners in combination with upper-room air UVGI. Culturing, direct microscopy, and optical particle counting revealed similar CADRm. The ACs performed similarly when challenged with three different microorganisms. Testing two of the ACs showed that no additional air cleaning was provided with the operation of an internal UV-C lamp; the internal UV-C lamps, however, inactivated 75% of fungal spores and 97% of bacteria cells captured in the air filter medium within 60 min.

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Methodology to Perform Clean Air Delivery Rate Type Determinations with Microbiological Aerosols

Cited by 2 publications

References 5 publications

Impact of Relative Humidity and Collection Media on Mycobacteriophage D29 Aerosol

Impact of Relative Humidity and Collection Media on Mycobacteriophage D29 Aerosol

UV Air Cleaners and Upper-Room Air Ultraviolet Germicidal Irradiation for Controlling Airborne Bacteria and Fungal Spores

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