Indoor Air 2015; 25: 231–234 wileyonlinelibrary.com/journal/ina Printed in Singapore. All rights reserved
© 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd INDOOR AIR doi:10.1111/ina.12199
Editorial Connect or stagnate: the future of indoor air sciences ‘A hidden connection is stronger than an obvious one’. – Heraclitus of Ephesus The study of buildings, and in particular indoor air science, has great intellectual merit. Buildings are highly heterogeneous, with steep spatial gradients in materials, environmental conditions, and occupant activities. Buildings are dynamic, changing over timescales that range from seconds (e.g., as HVAC systems cycle or wind velocities that affect ventilation change) to decades (e.g., as buildings age or are renovated). Buildings are complex systems comprising interconnected and complex subsystems. Given these attributes of buildings, one might conclude that the indoor air sciences are ripe for cross-disciplinary research. Yet indoor air scientists all too often work in narrow trenches, interacting primarily with those they have interacted with for years, content to dig more deeply into that of which they already have significant knowledge, and unaware of the connections that their work may have to those who dig in other trenches. In these ‘hidden’ connections lie opportunities for significant discoveries, new ways of solving problems, and—in a nutshell—strong advancement of the indoor air sciences. Perhaps paraphrasing Heraclitus, Friedrich Nietzsche wrote that, ‘Invisible threads are the strongest ties’. Maybe answers to problems that have stumped our community for years lie nearby, but we have missed their presence because of the narrow blinders that we choose to wear. Failure to recognize the hidden threads jeopardizes the vitality of our field. Cultivating connections ought to be a priority as we strive to advance knowledge in our field. Figure 1 illustrates the interconnected nature of the indoor air sciences. Some of these connections are unidirectional, and some are bidirectional. The reader might want to add, subtract, or merge some topics. Regardless of the fine details, the primary points hold the following: The overall system is complex, subsystems are complex in and of themselves, and connections between subsystems play major roles in defining the attributes of the larger system. In this editorial, I provide just a few examples of the many connections illustrated in Figure 1 and suggest a few more that are ripe for exploration over the next decade or more. Building energy use will continue to be a target of conservation efforts for the foreseeable future. As such, it seems logical to identify and better understand connections between the building energy subsystem and
other subsystems shown in Figure 1. For example, in what ways are building energy systems and conservation measures connected to indoor chemistry and microbiology? Such connections are not obvious in the existing literature. Since 1990, there have been nearly 3300 papers related to building energy use published in peer-reviewed journals. Remarkably, none of these papers connects explicitly to indoor chemistry, and only a handful makes connections to indoor microbiology, for example, biofilm growth on cooling coils (Bahnfleth, 2011). Researchers who acknowledge the intersection between building energy use and microbiology typically treat the latter as ‘background’ information, or as additional factors that were monitored during a field campaign without attempting to connect these features to the nuances of building energy use. How well established are the connections between indoor chemistry and microbiology? A search of the Web of Science with a wide range of terms relevant to indoor microbiology leads to slightly more than 2400 papers published in peer-reviewed journals since 1990. A similar search on indoor chemistry yields nearly 550 papers. But other than several papers that have focused on the chemical composition of microbial VOCs and other products of indoor microbes, the intersection of these two topics is only exhibited in a few tens of papers, with very few describing how chemical reactions might affect indoor microbes. As one specific example, a research team described an increasing susceptibility of bamboo flooring to fungal growth following exposure to ozone at relatively high concentrations, with evidence of surface compositional changes that may have enhanced fungal growth (Hoang et al., 2014). Does oxidative aging at more typical indoor ozone concentrations over many years change the nature of some indoor materials enough to affect their susceptibility to fungal growth, or even to the nature of microbes that colonize them? Would such knowledge change the materials chosen for building construction? What other connections between indoor chemistry and microbiology should be explored? Indoor microbiology and chemistry are each connected to indoor environmental conditions and may vary significantly across gradients in those conditions. For example, residential indoor temperatures can vary by 40°C or more between supply ducts in air-conditioned homes and attics during hot summer days. Extreme temperature gradients also occur across
Editorial
Fig. 1 Interconnectedness of the subsystems that comprise the indoor air sciences
external wall cavities and between those cavities and the occupied space. How do microbes vary across such gradients? Low et al. (2011) observed a 12-fold decrease in Aspergillus fumigatus allergenicity (IgEbinding capacity) as growth temperature was increased from 17 to 32°C, well within the temperature range observed in many buildings. In that study, potato dextrose agar was used as a substrate. Would similar results be observed for common indoor substrates? What about for other fungi? Because of the spatial and temporal variability of temperature and other environmental factors, is it possible that fungi of the same species but growing in different parts of a building would have different impacts on occupants, even with similar exposure conditions? Answers to these questions cannot be found in the published literature. Connections remain to be discovered. Direct solar radiation (i.e., sunlight through a window) has rarely been studied with respect to its impact on indoor air quality. For example, until recently, it was generally assumed that the attenuation of solar radiation into buildings is simply too great to form hydroxyl radicals via photolytic pathways. But Alvarez et al. (2013) observed that photolysis of nitrous acid indoors can contribute significantly to hydroxyl radical formation. They measured hydroxyl radical concentrations in a school building influenced by direct sunlight that were an order of magnitude greater than that typically predicted with indoor chemistry models (Carslaw, 2007; Sarwar et al., 2002; Weschler and Shields, 1996). This work demonstrates potentially important connections between sunlight, building design and operation (specifically windows and daylighting), and indoor air chemistry. This example underscores the complexity of indoor air sciences and indicates potential for many more hidden connections to be discovered. Central to the connections found in the indoor air sciences are building occupants, arguably the most complicated of all subsystems in Figure 1. Occupants 232
are connected to almost every aspect of the indoor air sciences. We ventilate by opening windows, activate sources (e.g., gas stoves, candles), set thermostats, clean indoor surfaces, purchase and install HVAC filters, operate portable air cleaners, purchase and apply cleaning agents and air fresheners, activate fans, liberate water vapor through cooking and cleaning, and more. These actions influence multiple other subsystems. We also disseminate microbes from our skin, hair, nostrils, and gut (e.g., Fox et al., 2008; Hospodsky et al., 2012), and our skin oils participate in chemical reactions with ozone and other oxidants that generate airborne reaction products (e.g., Wisthaler et al., 2005). And, of course, occupants are affected by other subsystems, with outcomes of interest including acute and chronic health effects, thermal comfort, work performance, and learning experiences. Given the importance of occupant behavior on the indoor air sciences, it is surprising that the social sciences are not better represented in our field. Our community has benefitted from important research related to human perceptions of indoor air quality and resulting worker productivity (e.g., Fang et al., 2004; Wargocki et al., 1999, 2000). Others have attempted to link certain human personality traits to sick building syndrome (SBS) symptoms (Berglund and Gunnarsson, 2000; Runeson et al., 2004). A deeper understanding of psychosocial attributes of humans and how they affect occupant behavior and perceptions in buildings could shed light on the interpretation of laboratory and field data involving human subjects. Are there inherent personality traits or experiences that affect how one perceives indoor environmental quality, or how one perceives and arranges space (which can, in turn, affect emissions, airflow patterns, chemistry, etc.)? How do personality traits affect the products one purchases, how often and when someone opens a window, whether someone uses an exhaust hood while cooking, whether and how much someone uses scenting agents, how one learns, and how open one is to changing behavior? Such knowledge could be invaluable in developing improved population-based exposure models and for understanding variances in perceived indoor air quality and even pollutant concentrations in large field studies. Is it possible to operate building zones to better suit collective personality traits for the occupants in that zone? The benefits of greater knowledge related to occupant connections with other subsystems will not come until we look beyond our own trenches to those occupied by psychologists, communication scientists, and others. Where should we be looking to build fruitful connections for the future? There are certain trends that are obvious and can serve as guideposts. A few of these are highlighted below. Climate change will undoubtedly have a direct connection to indoor air quality as buildings in some areas
Editorial will be challenged by increases in precipitation and flooding, increases in the frequency of heat waves, and increases in outdoor particles associated with wildfires and dust storms. How we design, construct, and operate buildings and how building occupants respond to these challenges will materially affect indoor environmental quality. In a previous editorial, Spengler (2012) described many potential connections between climate change, indoor environments, and health. There remains much work to be done to understand the strength of these connections. What additional connections, if any, remain hidden? Another evident global trend is rapid urbanization. ‘The urban population in 2014 accounted for 54% of the total global population, up from 34% in 1960 and continues to grow’. (http://www.who.int/ gho/urban_health/situation_trends/urban_population_ growth_text/en/) In general, more people are working and living close to major roadways than ever before. For example, in the United States, 11% of the population now lives within 100 m of a four-lane highway (Brugge et al., 2007). The urbanization trend suggests greater population exposure to pollutants associated with tailpipe emissions. Beyond the tailpipe, roadways also tend to accumulate metals in dust, for example, from catalytic converters, tire and brake wear, as well as latex allergens associated with tires (e.g., Adachi and Tainosho, 2004; Miguel et al., 1996). As this roadway dust migrates into nearby homes, how do the metals and latex allergens affect occupant exposures and health? Do they influence indoor microbiology in buildings near roadways? How can buildings of various types be better designed or retrofitted to reduce population exposures to roadway pollution, and how would such changes affect other subsystems? Like climate change, many subsystem connections might strongly
influence indoor environmental quality as a result of urbanization. Can we recognize and reveal the hidden connections? Trends for which applications are rapidly outpacing the indoor air sciences are the growth in use of green building materials and green consumer products, as well as engineered nanomaterials in building materials and consumer products. What are the short- and longterm consequences of these products on the health of building occupants, indoor microbiology, indoor chemistry, and other subsystems of the indoor air sciences? So many connections yet to be made! From high-throughput DNA sequencing to proton transfer reaction mass spectrometry to big data, there are powerful tools developed for other disciplines that are now beginning to be used in the indoor air sciences. These tools will help to uncover some hidden connections. But significant advancements in research also require creativity, thinking outside the box, and risktaking. These attributes define great inventors and business entrepreneurs. Steve Jobs, the late cofounder of Apple Computer, once said that, ‘Creativity is just connecting things’. It sounds simple, but it will take time for a field rooted in trench digging to think more broadly and to open up our minds to the superpositioning of otherwise disparate knowledge. Creativity will advance our field. Let’s start connecting things. Acknowledgements
The author thanks Leslie McCroddan for development of Figure 1 and Bill Nazaroff for his kind review and comments on this editorial. Richard L Corsi
References Adachi, K. and Tainosho, Y. (2004) Characterization of heavy metal particles embedded in tire dust, Environ. Int., 30, 1009– 1017. Alvarez, E.G., Amedro, D., Afif, C., Gligorovski, S., Schoemacker, C., Fittschen, C., Doussin, J.-F. and Wortham, H. (2013) Unexpectedly high indoor hydroxyl radical concentrations associated with nitrous acid, Proc. Natl. Acad. Sci. USA, 110, 13294–13299. Bahnfleth, W.P. (2011) UVGI in air handlers, ASHRAE J., 53, 70–72. Berglund, B. and Gunnarsson, A.G. (2000) Relationships between occupant personality and the sick building syndrome explored, Indoor Air, 10, 152–169. Brugge, D., Durant, J.L. and Rioux, C. (2007) Near-highway pollutants in motor vehicle exhaust: a review of epidemiologic
evidence of cardiac and pulmonary health risks, Environ. Health, 6, 23. Carslaw, N. (2007) A new detailed chemical model for indoor air pollution, Atmos. Environ., 41, 1164–1179. Fang, L., Wyon, D.P., Clausen, G. and Fanger, P.O. (2004) Impact of indoor temperature and humidity in an office on perceived air quality, SBS symptoms and performance, Indoor Air, 14(Suppl. 7), 74–81. Fox, K., Castanha, E., Fox, A., Feigley, C. and Salzberg, D. (2008) Human K10 epithelial keratin is the most abundant protein in airborne dust of both occupied and unoccupied school rooms, J. Environ. Monit., 10, 55–59. Hoang, C., Nguyen, T., Stanley, D., Persily, A. and Corsi, R.L. (2014) Effect of ozonation on fungal resistance of bamboo and
oak flooring materials, Build. Environ., 81, 226–233. Hospodsky, D., Qian, J., Nazaroff, W.W., Yamamoto, N., Bibby, K., RismaniYazdi, H. and Peccia, J. (2012) Human occupancy as a source of indoor airborne bacteria, PLoS ONE, 7, e34867. Low, S.Y., Dannemiller, K., Yao, M., Yamamoto, N. and Peccia, J. (2011) The allergenicity of Aspergillus fumigatus conidia is influenced by growth temperature, Fungal Biol., 115, 625–632. Miguel, A.G., Cass, G.R., Weiss, J. and Glovsky, M.M. (1996) Latex allergens in tire dust and airborne particles, Environ. Health Perspect., 104, 1180–1186. Runeson, R., Norb€ ack, D., Klinteberg, H. and Edling, C. (2004) The influence of personality, measured by the Karolinska Scales of Personality (KSP), on
233
Editorial symptoms among subjects in suspected sick buildings, Indoor Air, 14, 394–404. Sarwar, G., Corsi, R., Kimura, Y., Allen, D. and Weschler, C.J. (2002) Hydroxyl radicals in indoor environments, Atmos. Environ., 36, 3973–3988. Spengler, J.D. (2012) Climate change, indoor environments, and health, Indoor Air, 22, 89–95. Wargocki, P., Wyon, D.P., Baik, Y.K., Clausen, G. and Fanger, P.O. (1999)
234
Perceived air quality, sick building syndrome (SBS) symptoms and productivity in an office with two different pollution loads, Indoor Air, 9, 165–179. Wargocki, P., Wyon, D.P., Sundell, J., Clausen, G. and Fanger, P.O. (2000) The effects of outdoor air supply rate in an office on perceived air quality, sick building syndrome (SBS) symptoms and productivity, Indoor Air, 10, 222–236.
Weschler, C.J. and Shields, H.C. (1996) Production of the hydroxyl radical in indoor air, Environ. Sci. Technol., 30, 3250–3258. Wisthaler, A., Tam as, G., Wyon, D.P., Strøm-Tejsen, P., Space, D., Beauchamp, J., Hansel, A., M€ ark, T.D. and Weschler, C.J. (2005) Products of ozone-initiated chemistry in a simulated aircraft environment, Environ. Sci. Technol., 39, 4823– 4832.
Copyright of Indoor Air is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.
© 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd INDOOR AIR doi:10.1111/ina.12199
Editorial Connect or stagnate: the future of indoor air sciences ‘A hidden connection is stronger than an obvious one’. – Heraclitus of Ephesus The study of buildings, and in particular indoor air science, has great intellectual merit. Buildings are highly heterogeneous, with steep spatial gradients in materials, environmental conditions, and occupant activities. Buildings are dynamic, changing over timescales that range from seconds (e.g., as HVAC systems cycle or wind velocities that affect ventilation change) to decades (e.g., as buildings age or are renovated). Buildings are complex systems comprising interconnected and complex subsystems. Given these attributes of buildings, one might conclude that the indoor air sciences are ripe for cross-disciplinary research. Yet indoor air scientists all too often work in narrow trenches, interacting primarily with those they have interacted with for years, content to dig more deeply into that of which they already have significant knowledge, and unaware of the connections that their work may have to those who dig in other trenches. In these ‘hidden’ connections lie opportunities for significant discoveries, new ways of solving problems, and—in a nutshell—strong advancement of the indoor air sciences. Perhaps paraphrasing Heraclitus, Friedrich Nietzsche wrote that, ‘Invisible threads are the strongest ties’. Maybe answers to problems that have stumped our community for years lie nearby, but we have missed their presence because of the narrow blinders that we choose to wear. Failure to recognize the hidden threads jeopardizes the vitality of our field. Cultivating connections ought to be a priority as we strive to advance knowledge in our field. Figure 1 illustrates the interconnected nature of the indoor air sciences. Some of these connections are unidirectional, and some are bidirectional. The reader might want to add, subtract, or merge some topics. Regardless of the fine details, the primary points hold the following: The overall system is complex, subsystems are complex in and of themselves, and connections between subsystems play major roles in defining the attributes of the larger system. In this editorial, I provide just a few examples of the many connections illustrated in Figure 1 and suggest a few more that are ripe for exploration over the next decade or more. Building energy use will continue to be a target of conservation efforts for the foreseeable future. As such, it seems logical to identify and better understand connections between the building energy subsystem and
other subsystems shown in Figure 1. For example, in what ways are building energy systems and conservation measures connected to indoor chemistry and microbiology? Such connections are not obvious in the existing literature. Since 1990, there have been nearly 3300 papers related to building energy use published in peer-reviewed journals. Remarkably, none of these papers connects explicitly to indoor chemistry, and only a handful makes connections to indoor microbiology, for example, biofilm growth on cooling coils (Bahnfleth, 2011). Researchers who acknowledge the intersection between building energy use and microbiology typically treat the latter as ‘background’ information, or as additional factors that were monitored during a field campaign without attempting to connect these features to the nuances of building energy use. How well established are the connections between indoor chemistry and microbiology? A search of the Web of Science with a wide range of terms relevant to indoor microbiology leads to slightly more than 2400 papers published in peer-reviewed journals since 1990. A similar search on indoor chemistry yields nearly 550 papers. But other than several papers that have focused on the chemical composition of microbial VOCs and other products of indoor microbes, the intersection of these two topics is only exhibited in a few tens of papers, with very few describing how chemical reactions might affect indoor microbes. As one specific example, a research team described an increasing susceptibility of bamboo flooring to fungal growth following exposure to ozone at relatively high concentrations, with evidence of surface compositional changes that may have enhanced fungal growth (Hoang et al., 2014). Does oxidative aging at more typical indoor ozone concentrations over many years change the nature of some indoor materials enough to affect their susceptibility to fungal growth, or even to the nature of microbes that colonize them? Would such knowledge change the materials chosen for building construction? What other connections between indoor chemistry and microbiology should be explored? Indoor microbiology and chemistry are each connected to indoor environmental conditions and may vary significantly across gradients in those conditions. For example, residential indoor temperatures can vary by 40°C or more between supply ducts in air-conditioned homes and attics during hot summer days. Extreme temperature gradients also occur across
Editorial
Fig. 1 Interconnectedness of the subsystems that comprise the indoor air sciences
external wall cavities and between those cavities and the occupied space. How do microbes vary across such gradients? Low et al. (2011) observed a 12-fold decrease in Aspergillus fumigatus allergenicity (IgEbinding capacity) as growth temperature was increased from 17 to 32°C, well within the temperature range observed in many buildings. In that study, potato dextrose agar was used as a substrate. Would similar results be observed for common indoor substrates? What about for other fungi? Because of the spatial and temporal variability of temperature and other environmental factors, is it possible that fungi of the same species but growing in different parts of a building would have different impacts on occupants, even with similar exposure conditions? Answers to these questions cannot be found in the published literature. Connections remain to be discovered. Direct solar radiation (i.e., sunlight through a window) has rarely been studied with respect to its impact on indoor air quality. For example, until recently, it was generally assumed that the attenuation of solar radiation into buildings is simply too great to form hydroxyl radicals via photolytic pathways. But Alvarez et al. (2013) observed that photolysis of nitrous acid indoors can contribute significantly to hydroxyl radical formation. They measured hydroxyl radical concentrations in a school building influenced by direct sunlight that were an order of magnitude greater than that typically predicted with indoor chemistry models (Carslaw, 2007; Sarwar et al., 2002; Weschler and Shields, 1996). This work demonstrates potentially important connections between sunlight, building design and operation (specifically windows and daylighting), and indoor air chemistry. This example underscores the complexity of indoor air sciences and indicates potential for many more hidden connections to be discovered. Central to the connections found in the indoor air sciences are building occupants, arguably the most complicated of all subsystems in Figure 1. Occupants 232
are connected to almost every aspect of the indoor air sciences. We ventilate by opening windows, activate sources (e.g., gas stoves, candles), set thermostats, clean indoor surfaces, purchase and install HVAC filters, operate portable air cleaners, purchase and apply cleaning agents and air fresheners, activate fans, liberate water vapor through cooking and cleaning, and more. These actions influence multiple other subsystems. We also disseminate microbes from our skin, hair, nostrils, and gut (e.g., Fox et al., 2008; Hospodsky et al., 2012), and our skin oils participate in chemical reactions with ozone and other oxidants that generate airborne reaction products (e.g., Wisthaler et al., 2005). And, of course, occupants are affected by other subsystems, with outcomes of interest including acute and chronic health effects, thermal comfort, work performance, and learning experiences. Given the importance of occupant behavior on the indoor air sciences, it is surprising that the social sciences are not better represented in our field. Our community has benefitted from important research related to human perceptions of indoor air quality and resulting worker productivity (e.g., Fang et al., 2004; Wargocki et al., 1999, 2000). Others have attempted to link certain human personality traits to sick building syndrome (SBS) symptoms (Berglund and Gunnarsson, 2000; Runeson et al., 2004). A deeper understanding of psychosocial attributes of humans and how they affect occupant behavior and perceptions in buildings could shed light on the interpretation of laboratory and field data involving human subjects. Are there inherent personality traits or experiences that affect how one perceives indoor environmental quality, or how one perceives and arranges space (which can, in turn, affect emissions, airflow patterns, chemistry, etc.)? How do personality traits affect the products one purchases, how often and when someone opens a window, whether someone uses an exhaust hood while cooking, whether and how much someone uses scenting agents, how one learns, and how open one is to changing behavior? Such knowledge could be invaluable in developing improved population-based exposure models and for understanding variances in perceived indoor air quality and even pollutant concentrations in large field studies. Is it possible to operate building zones to better suit collective personality traits for the occupants in that zone? The benefits of greater knowledge related to occupant connections with other subsystems will not come until we look beyond our own trenches to those occupied by psychologists, communication scientists, and others. Where should we be looking to build fruitful connections for the future? There are certain trends that are obvious and can serve as guideposts. A few of these are highlighted below. Climate change will undoubtedly have a direct connection to indoor air quality as buildings in some areas
Editorial will be challenged by increases in precipitation and flooding, increases in the frequency of heat waves, and increases in outdoor particles associated with wildfires and dust storms. How we design, construct, and operate buildings and how building occupants respond to these challenges will materially affect indoor environmental quality. In a previous editorial, Spengler (2012) described many potential connections between climate change, indoor environments, and health. There remains much work to be done to understand the strength of these connections. What additional connections, if any, remain hidden? Another evident global trend is rapid urbanization. ‘The urban population in 2014 accounted for 54% of the total global population, up from 34% in 1960 and continues to grow’. (http://www.who.int/ gho/urban_health/situation_trends/urban_population_ growth_text/en/) In general, more people are working and living close to major roadways than ever before. For example, in the United States, 11% of the population now lives within 100 m of a four-lane highway (Brugge et al., 2007). The urbanization trend suggests greater population exposure to pollutants associated with tailpipe emissions. Beyond the tailpipe, roadways also tend to accumulate metals in dust, for example, from catalytic converters, tire and brake wear, as well as latex allergens associated with tires (e.g., Adachi and Tainosho, 2004; Miguel et al., 1996). As this roadway dust migrates into nearby homes, how do the metals and latex allergens affect occupant exposures and health? Do they influence indoor microbiology in buildings near roadways? How can buildings of various types be better designed or retrofitted to reduce population exposures to roadway pollution, and how would such changes affect other subsystems? Like climate change, many subsystem connections might strongly
influence indoor environmental quality as a result of urbanization. Can we recognize and reveal the hidden connections? Trends for which applications are rapidly outpacing the indoor air sciences are the growth in use of green building materials and green consumer products, as well as engineered nanomaterials in building materials and consumer products. What are the short- and longterm consequences of these products on the health of building occupants, indoor microbiology, indoor chemistry, and other subsystems of the indoor air sciences? So many connections yet to be made! From high-throughput DNA sequencing to proton transfer reaction mass spectrometry to big data, there are powerful tools developed for other disciplines that are now beginning to be used in the indoor air sciences. These tools will help to uncover some hidden connections. But significant advancements in research also require creativity, thinking outside the box, and risktaking. These attributes define great inventors and business entrepreneurs. Steve Jobs, the late cofounder of Apple Computer, once said that, ‘Creativity is just connecting things’. It sounds simple, but it will take time for a field rooted in trench digging to think more broadly and to open up our minds to the superpositioning of otherwise disparate knowledge. Creativity will advance our field. Let’s start connecting things. Acknowledgements
The author thanks Leslie McCroddan for development of Figure 1 and Bill Nazaroff for his kind review and comments on this editorial. Richard L Corsi
References Adachi, K. and Tainosho, Y. (2004) Characterization of heavy metal particles embedded in tire dust, Environ. Int., 30, 1009– 1017. Alvarez, E.G., Amedro, D., Afif, C., Gligorovski, S., Schoemacker, C., Fittschen, C., Doussin, J.-F. and Wortham, H. (2013) Unexpectedly high indoor hydroxyl radical concentrations associated with nitrous acid, Proc. Natl. Acad. Sci. USA, 110, 13294–13299. Bahnfleth, W.P. (2011) UVGI in air handlers, ASHRAE J., 53, 70–72. Berglund, B. and Gunnarsson, A.G. (2000) Relationships between occupant personality and the sick building syndrome explored, Indoor Air, 10, 152–169. Brugge, D., Durant, J.L. and Rioux, C. (2007) Near-highway pollutants in motor vehicle exhaust: a review of epidemiologic
evidence of cardiac and pulmonary health risks, Environ. Health, 6, 23. Carslaw, N. (2007) A new detailed chemical model for indoor air pollution, Atmos. Environ., 41, 1164–1179. Fang, L., Wyon, D.P., Clausen, G. and Fanger, P.O. (2004) Impact of indoor temperature and humidity in an office on perceived air quality, SBS symptoms and performance, Indoor Air, 14(Suppl. 7), 74–81. Fox, K., Castanha, E., Fox, A., Feigley, C. and Salzberg, D. (2008) Human K10 epithelial keratin is the most abundant protein in airborne dust of both occupied and unoccupied school rooms, J. Environ. Monit., 10, 55–59. Hoang, C., Nguyen, T., Stanley, D., Persily, A. and Corsi, R.L. (2014) Effect of ozonation on fungal resistance of bamboo and
oak flooring materials, Build. Environ., 81, 226–233. Hospodsky, D., Qian, J., Nazaroff, W.W., Yamamoto, N., Bibby, K., RismaniYazdi, H. and Peccia, J. (2012) Human occupancy as a source of indoor airborne bacteria, PLoS ONE, 7, e34867. Low, S.Y., Dannemiller, K., Yao, M., Yamamoto, N. and Peccia, J. (2011) The allergenicity of Aspergillus fumigatus conidia is influenced by growth temperature, Fungal Biol., 115, 625–632. Miguel, A.G., Cass, G.R., Weiss, J. and Glovsky, M.M. (1996) Latex allergens in tire dust and airborne particles, Environ. Health Perspect., 104, 1180–1186. Runeson, R., Norb€ ack, D., Klinteberg, H. and Edling, C. (2004) The influence of personality, measured by the Karolinska Scales of Personality (KSP), on
233
Editorial symptoms among subjects in suspected sick buildings, Indoor Air, 14, 394–404. Sarwar, G., Corsi, R., Kimura, Y., Allen, D. and Weschler, C.J. (2002) Hydroxyl radicals in indoor environments, Atmos. Environ., 36, 3973–3988. Spengler, J.D. (2012) Climate change, indoor environments, and health, Indoor Air, 22, 89–95. Wargocki, P., Wyon, D.P., Baik, Y.K., Clausen, G. and Fanger, P.O. (1999)
234
Perceived air quality, sick building syndrome (SBS) symptoms and productivity in an office with two different pollution loads, Indoor Air, 9, 165–179. Wargocki, P., Wyon, D.P., Sundell, J., Clausen, G. and Fanger, P.O. (2000) The effects of outdoor air supply rate in an office on perceived air quality, sick building syndrome (SBS) symptoms and productivity, Indoor Air, 10, 222–236.
Weschler, C.J. and Shields, H.C. (1996) Production of the hydroxyl radical in indoor air, Environ. Sci. Technol., 30, 3250–3258. Wisthaler, A., Tam as, G., Wyon, D.P., Strøm-Tejsen, P., Space, D., Beauchamp, J., Hansel, A., M€ ark, T.D. and Weschler, C.J. (2005) Products of ozone-initiated chemistry in a simulated aircraft environment, Environ. Sci. Technol., 39, 4823– 4832.
Copyright of Indoor Air is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.
