The Experts below are selected from a list of 318 Experts worldwide ranked by ideXlab platform
Hans Puxbaum - One of the best experts on this subject based on the ideXlab platform.
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Fungal Spores as potential ice nuclei in fog/cloud water and snow
2010Co-Authors: Heidi Bauer, Elisabeth Schueller, Fábio Luiz Teixeira Gonçalves, Hans PuxbaumAbstract:INTRODUCTION: In discussions about climate change and precipitation frequency biological ice nucleation has become an issue. While bacterial ice nucleation (IN) is already well characterized and even utilized in industrial processes such as the production of artificial snow or to improve freezing processes in food industry, less is known about the IN potential of Fungal Spores which are also ubiquitous in the atmosphere. A recent study performed at a mountain top in the Rocky Mountains suggests that Fungal Spores and/or pollen might play a role in increased IN abundance during periods of cloud cover (Bowers et al. 2009). In the present work concentrations of Fungal Spores in fog/cloud water and snow were determined.
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significant contributions of Fungal Spores to the organic carbon and to the aerosol mass balance of the urban atmospheric aerosol
Atmospheric Environment, 2008Co-Authors: Heidi Bauer, Elisabeth Schueller, Gert Weinke, Anna Berger, R Hitzenberger, Iain L Marr, Hans PuxbaumAbstract:Abstract Fungal Spores are ubiquitous components of atmospheric aerosols and are therefore also contributors to the organic carbon (OC) component and to the mass of PM10 (PM—particulate matter) aerosols. In this study we use spore counts and an experimentally derived factor of 13 pg C and of 33 pg fresh weight per spore for assessing quantitatively the contribution to OC and PM10. The concentrations of airborne Fungal Spores were determined at a suburban (Schafberg) and a traffic-dominated urban site (Rinnbockstrasse) in Vienna, Austria, during spring and summer. Fungal Spores OC ranged from 22 to 677 ng m−3 with a summer mean value of around 350 ng m−3 at the suburban site and 300 ng m−3 at the urban traffic site. At the suburban site Fungal Spores contributed on average 6% in spring and 14% in summer to aerosol OC mass concentration. At the traffic-dominated site Fungal Spores accounted for 2% of OC in spring and for 8% in summer. The Fungal contribution to PM10 was also notable and amounted to 3% and 7% at the suburban and to 1% and 4% at the urban site in spring and summer, respectively. Impactor measurements of OC at the suburban site showed that in summer Fungal Spores were predominant contributors to the coarse aerosol OC, and accounted on average for 60% of the OC in the PM2−10 fraction. Fungal Spores thus can be regarded as main components to PM10, total OC and, most importantly, coarse OC even in urban areas.
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arabitol and mannitol as tracers for the quantification of airborne Fungal Spores
Atmospheric Environment, 2008Co-Authors: Heidi Bauer, Magda Claeys, Reinhilde Vermeylen, Elisabeth Schueller, Gert Weinke, Anna Berger, Hans PuxbaumAbstract:Abstract Fungal Spores constitute a sizeable fraction of coarse organic carbon (OC) in the atmospheric aerosol. In order to avoid tedious spore count methods, tracers for quantifying the spore-OC in atmospheric aerosol are sought. Arabitol and mannitol have been proposed as such tracers, since no other emission sources for these compounds have been reported. By parallel investigations of spore counts and tracer determinations from PM10 filter samples we could derive quantitative relationships between the amounts of tracer compounds and the numbers of Spores in the atmosphere for different sites in the area of Vienna. We obtained over all average relationships of 1.2 pg arabitol spore−1, with a range of 0.8–1.8, and 1.7 pg mannitol spore−1, with a range of 1.2–2.4, with a clear site dependence. Thus, using these conversion factors from spore counts to spore-OC and spore-mass, along with analytical data for arabitol or mannitol in filter samples, the contribution of Fungal Spores to the OC and to the mass balance of atmospheric aerosol particles can be estimated.
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determination of the carbon content of airborne Fungal Spores
Analytical Chemistry, 2002Co-Authors: Heidi Bauer, Anne Kaspergiebl, F Zibuschka, R Hitzenberger, And Gunther F Kraus, Hans PuxbaumAbstract:Airborne Fungal Spores contribute potentially to the organic carbon of the atmospheric aerosol, mainly in the “coarse aerosol” size range 2.5−10 μm aerodynamic equivalent diameter (aed). Here, we report about a procedure to determine the organic carbon content of Fungal Spores frequently observed in the atmosphere. Furthermore, we apply a new (carbon/individual) factor to quantify the amount of Fungal-Spores-derived organic carbon in aerosol collected at a mountain site in Austria. Spores of representatives of Cladosporium sp., Aspergillus sp., Penicillium sp., and Alternaria sp., the four predominant airborne genera, were analyzed for their carbon content using two different analytical procedures. The result was an average carbon content of 13 pg C/spore (RSD, 46%), or expressed as a carbon-per-volume ratio, 0.38 pg C/μm3 (RSD, 30%). These values are comparable to conversion factors for bacteria and some representatives of the zooplankton. Because biopolymers are suspected of interfering with elemental c...
Shelly L. Miller - One of the best experts on this subject based on the ideXlab platform.
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Ultraviolet germicidal irradiation inactivation of airborne Fungal Spores and bacteria in upper-room air and HVAC in-duct configurations
Journal of Environmental Engineering and Science, 2007Co-Authors: Elmira Kujundzic, Mark Hernandez, Shelly L. MillerAbstract:The efficacy of ultraviolet germicidal irradiation (UVGI) for inactivating airborne Fungal Spores and bacterial vegetative cells was evaluated under three configurations — intrinsic, upper-room air, and in-duct. Correspondingly, experiments were performed in (1) a pilot-scale chamber (0.8 m3), fitted with four corner UV lamps that irradiated the entire chamber (average UV fluence rate 10.6 ± 0.8 µJ s–1cm–2); (2) a full-scale room (87 m3), fitted with a UVGI system that irradiated the top 30 cm of the room (5 fixtures, 216 W total lamp power, average upper-zone UV fluence rate 26 ± 1 µJ s–1cm–2); and (3) the supply air duct of a heating ventilation and air-conditioning (HVAC) system. Fungal Spores of Aspergillus versicolor and vegetative cells of bacterium Mycobacterium parafortuitum were aerosolized continuously such that their numbers and physiologic state were comparable both with and without the UVGI lamps operating. The Z value (UVGI inactivation rate normalized to UVGI fluence rate) was estimated to be 1.2 ± 0.4 x 10–4 cm2 µJ–1 for aerosolized A. versicolor. Upper-room air UVGI inactivated culturable airborne Fungal Spores with a first-order rate constant of 0.4 ± 0.2 h–1. Ultraviolet lamps enclosed in ventilation system ductwork inactivated Fungal Spores and vegetative bacterial cells at single-pass efficiencies of 75% and 87%, respectively, at an air stream velocity of 2.2 m s–1. There was no detected inactivation of Fungal Spores and vegetative bacterial cells at an air stream velocity of 5.1 m s–1. Key words: bioaerosols, UVGI, air disinfection.
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uv air cleaners and upper room air ultraviolet germicidal irradiation for controlling airborne bacteria and Fungal Spores
Journal of Occupational and Environmental Hygiene, 2006Co-Authors: Elmira Kujundzic, Fatimah Matalkah, Cody J. Howard, Mark Hernandez, Shelly L. MillerAbstract: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 incorporatedUVlamp(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 upperroom 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 upperroom air UVGI. In addition, the disinfection performance of a UV-C lamp internal to one of the ACs was evaluated by estimating ...
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UV air cleaners and upper-room air ultraviolet germicidal irradiation for controlling airborne bacteria and Fungal Spores
Journal of Occupational and Environmental Hygiene, 2006Co-Authors: Elmira Kujundzic, Fatimah Matalkah, Cody J. Howard, Mark Hernandez, Shelly L. MillerAbstract: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.
Ting-lin Huang - One of the best experts on this subject based on the ideXlab platform.
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inactivation of four genera of dominant Fungal Spores in groundwater using uv and uv pms efficiency and mechanisms
Chemical Engineering Journal, 2017Co-Authors: Xiang-qian Xu, Ting-lin HuangAbstract:Abstract Outbreaks of fungi in groundwater sources of drinking water can produce taste and odor problems, and cause ill health in immunocompromised individuals. The groundwater treatment process is simple; generally, only disinfection is used in China. Efficient disinfection methods to control fungi are required. In the present study, we investigated the inactivation efficiency of 4 dominant genera of Fungal Spores (a Trichoderma sp., Acremonium sp. , Penicillium sp., and Cladosporium sp.) using ultraviolet irradiation (UV) and UV-based advanced oxidation processes, and explored the mechanisms of inactivation by monitoring the leakage of intracellular contents and changes in spore morphology. The inactivation of Fungal Spores is consistent with first-order Chick–Watson kinetics. The resistance of each of the fungi to UV ( Cladosporium sp. > Penicillium sp. > Acremonium sp. > Trichoderma sp.) was greater than that of E. coli , due to their larger sizes and more complex structures. UV/peroxymonosulfate (UV/PMS) treatment had a markedly better inactivation rate constant than UV alone. Furthermore, UV/PMS exhibited similar effects on Fungal inactivation in phosphate buffer and in groundwater, whereas UV inactivation efficiency markedly decreased in groundwater. UV/PMS treatment resulted in cell wall and cell membrane damage, the leakage of intracellular contents, and the shriveling of Fungal Spores, due to the reactive radicals produced by the treatment. Thus, UV/PMS is a promising method to control fungi in drinking water sources.
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inactivation of three genera of dominant Fungal Spores in groundwater using chlorine dioxide effectiveness influencing factors and mechanisms
Water Research, 2017Co-Authors: Xiang-qian Xu, Ting-lin HuangAbstract:Abstract Fungi in aquatic environments received more attention recently; therefore, the characteristics of inactivation of Fungal Spores by widely used disinfectants are quite important. Nonetheless, the inactivation efficacy of Fungal Spores by chlorine dioxide is poorly known. In this study, the effectiveness of chlorine dioxide at inactivation of three dominant genera of Fungal Spores isolated from drinking groundwater and the effects of pH, temperature, chlorine dioxide concentration, and humic acid were evaluated. The inactivation mechanisms were explored by analyzing the leakage of intracellular substances, the increase in extracellular adenosine triphosphate (ATP), deoxyribonucleic acid (DNA), and proteins as well as the changes in spore morphology. The kinetics of inactivation by chlorine dioxide fitted the Chick-Watson model, and different Fungal species showed different resistance to chlorine dioxide inactivation, which was in the following order: Cladosporium sp.> Trichoderma sp. > Penicillium sp., which are much more resistant than Escherichia coli . Regarding the three genera of Fungal Spores used in this study, chlorine dioxide was more effective at inactivation of Fungal Spores than chlorine. The effect of disinfectant concentration and temperature was positive, and the impact of pH levels (6.0 and 7.0) was insignificant, whereas the influence of water matrices on the inactivation efficiency was negative. The increased concentration of characteristic extracellular substances and changes of spore morphology were observed after inactivation with chlorine dioxide and were due to cell wall and cell membrane damage in Fungal Spores, causing the leakage of intracellular substances and death of a Fungal spore.
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Inactivation Efficiency and Mechanism of Three Dominant Fungal Spores in Drinking Groundwater by Chlorine
Huan jing ke xue= Huanjing kexue, 2016Co-Authors: Ting-lin Huang, Jian-chao Zhao, Xiang-qian XuAbstract:The outbreak of fungi in drinking groundwater sources can produce odor, cause toxicity and form lots of visible flocs, which seriously affect the drinking water quality. In this study, the inactivation efficiency of three dominant Fungal Spores Trichoderma, Penicillium, Cladosporium by chlorine was conducted, and the inactivation mechanism was explored by monitoring the hydrophobicity, the leakage of intracellular substances, the increase of extracellular adenosine triphosphate (ATP), deoxyribonucleic acid (DNA) and proteins, and the change of Spores' morphology. The results showed that the inactivation of Fungal Spores was consistent with first-order kinetics and satisfied the Chick model. The resistance to chlorine was in sequence of Trichoderma > Penicillium > Cladosporium, the larger size the Fungal Spores and the more hydrophilicity the Fungal Spores, the higher the inactivation efficiency. Chlorination resulted in the remarkable leakage of intracellular compounds, the increase of extracellular characteristic compounds (ATP, DNA and protein), the damage of the cell surface, and the Fungal Spores recessed and wrinkled. In summary, chlorine firstly reacted with Spores' surface and reduced their cultivability, and then resulted in the damage to the permeability barrier of the Spores and the release of intracellular characteristic compounds, and finally the viability of Spores was damaged.
Heidi Bauer - One of the best experts on this subject based on the ideXlab platform.
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Fungal Spores as potential ice nuclei in fog/cloud water and snow
2010Co-Authors: Heidi Bauer, Elisabeth Schueller, Fábio Luiz Teixeira Gonçalves, Hans PuxbaumAbstract:INTRODUCTION: In discussions about climate change and precipitation frequency biological ice nucleation has become an issue. While bacterial ice nucleation (IN) is already well characterized and even utilized in industrial processes such as the production of artificial snow or to improve freezing processes in food industry, less is known about the IN potential of Fungal Spores which are also ubiquitous in the atmosphere. A recent study performed at a mountain top in the Rocky Mountains suggests that Fungal Spores and/or pollen might play a role in increased IN abundance during periods of cloud cover (Bowers et al. 2009). In the present work concentrations of Fungal Spores in fog/cloud water and snow were determined.
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significant contributions of Fungal Spores to the organic carbon and to the aerosol mass balance of the urban atmospheric aerosol
Atmospheric Environment, 2008Co-Authors: Heidi Bauer, Elisabeth Schueller, Gert Weinke, Anna Berger, R Hitzenberger, Iain L Marr, Hans PuxbaumAbstract:Abstract Fungal Spores are ubiquitous components of atmospheric aerosols and are therefore also contributors to the organic carbon (OC) component and to the mass of PM10 (PM—particulate matter) aerosols. In this study we use spore counts and an experimentally derived factor of 13 pg C and of 33 pg fresh weight per spore for assessing quantitatively the contribution to OC and PM10. The concentrations of airborne Fungal Spores were determined at a suburban (Schafberg) and a traffic-dominated urban site (Rinnbockstrasse) in Vienna, Austria, during spring and summer. Fungal Spores OC ranged from 22 to 677 ng m−3 with a summer mean value of around 350 ng m−3 at the suburban site and 300 ng m−3 at the urban traffic site. At the suburban site Fungal Spores contributed on average 6% in spring and 14% in summer to aerosol OC mass concentration. At the traffic-dominated site Fungal Spores accounted for 2% of OC in spring and for 8% in summer. The Fungal contribution to PM10 was also notable and amounted to 3% and 7% at the suburban and to 1% and 4% at the urban site in spring and summer, respectively. Impactor measurements of OC at the suburban site showed that in summer Fungal Spores were predominant contributors to the coarse aerosol OC, and accounted on average for 60% of the OC in the PM2−10 fraction. Fungal Spores thus can be regarded as main components to PM10, total OC and, most importantly, coarse OC even in urban areas.
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arabitol and mannitol as tracers for the quantification of airborne Fungal Spores
Atmospheric Environment, 2008Co-Authors: Heidi Bauer, Magda Claeys, Reinhilde Vermeylen, Elisabeth Schueller, Gert Weinke, Anna Berger, Hans PuxbaumAbstract:Abstract Fungal Spores constitute a sizeable fraction of coarse organic carbon (OC) in the atmospheric aerosol. In order to avoid tedious spore count methods, tracers for quantifying the spore-OC in atmospheric aerosol are sought. Arabitol and mannitol have been proposed as such tracers, since no other emission sources for these compounds have been reported. By parallel investigations of spore counts and tracer determinations from PM10 filter samples we could derive quantitative relationships between the amounts of tracer compounds and the numbers of Spores in the atmosphere for different sites in the area of Vienna. We obtained over all average relationships of 1.2 pg arabitol spore−1, with a range of 0.8–1.8, and 1.7 pg mannitol spore−1, with a range of 1.2–2.4, with a clear site dependence. Thus, using these conversion factors from spore counts to spore-OC and spore-mass, along with analytical data for arabitol or mannitol in filter samples, the contribution of Fungal Spores to the OC and to the mass balance of atmospheric aerosol particles can be estimated.
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determination of the carbon content of airborne Fungal Spores
Analytical Chemistry, 2002Co-Authors: Heidi Bauer, Anne Kaspergiebl, F Zibuschka, R Hitzenberger, And Gunther F Kraus, Hans PuxbaumAbstract:Airborne Fungal Spores contribute potentially to the organic carbon of the atmospheric aerosol, mainly in the “coarse aerosol” size range 2.5−10 μm aerodynamic equivalent diameter (aed). Here, we report about a procedure to determine the organic carbon content of Fungal Spores frequently observed in the atmosphere. Furthermore, we apply a new (carbon/individual) factor to quantify the amount of Fungal-Spores-derived organic carbon in aerosol collected at a mountain site in Austria. Spores of representatives of Cladosporium sp., Aspergillus sp., Penicillium sp., and Alternaria sp., the four predominant airborne genera, were analyzed for their carbon content using two different analytical procedures. The result was an average carbon content of 13 pg C/spore (RSD, 46%), or expressed as a carbon-per-volume ratio, 0.38 pg C/μm3 (RSD, 30%). These values are comparable to conversion factors for bacteria and some representatives of the zooplankton. Because biopolymers are suspected of interfering with elemental c...
Elmira Kujundzic - One of the best experts on this subject based on the ideXlab platform.
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Ultraviolet germicidal irradiation inactivation of airborne Fungal Spores and bacteria in upper-room air and HVAC in-duct configurations
Journal of Environmental Engineering and Science, 2007Co-Authors: Elmira Kujundzic, Mark Hernandez, Shelly L. MillerAbstract:The efficacy of ultraviolet germicidal irradiation (UVGI) for inactivating airborne Fungal Spores and bacterial vegetative cells was evaluated under three configurations — intrinsic, upper-room air, and in-duct. Correspondingly, experiments were performed in (1) a pilot-scale chamber (0.8 m3), fitted with four corner UV lamps that irradiated the entire chamber (average UV fluence rate 10.6 ± 0.8 µJ s–1cm–2); (2) a full-scale room (87 m3), fitted with a UVGI system that irradiated the top 30 cm of the room (5 fixtures, 216 W total lamp power, average upper-zone UV fluence rate 26 ± 1 µJ s–1cm–2); and (3) the supply air duct of a heating ventilation and air-conditioning (HVAC) system. Fungal Spores of Aspergillus versicolor and vegetative cells of bacterium Mycobacterium parafortuitum were aerosolized continuously such that their numbers and physiologic state were comparable both with and without the UVGI lamps operating. The Z value (UVGI inactivation rate normalized to UVGI fluence rate) was estimated to be 1.2 ± 0.4 x 10–4 cm2 µJ–1 for aerosolized A. versicolor. Upper-room air UVGI inactivated culturable airborne Fungal Spores with a first-order rate constant of 0.4 ± 0.2 h–1. Ultraviolet lamps enclosed in ventilation system ductwork inactivated Fungal Spores and vegetative bacterial cells at single-pass efficiencies of 75% and 87%, respectively, at an air stream velocity of 2.2 m s–1. There was no detected inactivation of Fungal Spores and vegetative bacterial cells at an air stream velocity of 5.1 m s–1. Key words: bioaerosols, UVGI, air disinfection.
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uv air cleaners and upper room air ultraviolet germicidal irradiation for controlling airborne bacteria and Fungal Spores
Journal of Occupational and Environmental Hygiene, 2006Co-Authors: Elmira Kujundzic, Fatimah Matalkah, Cody J. Howard, Mark Hernandez, Shelly L. MillerAbstract: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 incorporatedUVlamp(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 upperroom 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 upperroom air UVGI. In addition, the disinfection performance of a UV-C lamp internal to one of the ACs was evaluated by estimating ...
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UV air cleaners and upper-room air ultraviolet germicidal irradiation for controlling airborne bacteria and Fungal Spores
Journal of Occupational and Environmental Hygiene, 2006Co-Authors: Elmira Kujundzic, Fatimah Matalkah, Cody J. Howard, Mark Hernandez, Shelly L. MillerAbstract: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.
