Hot off the press, a new review on health in the built environment is available today!  The article is found here, but an open-access, view-only version is available here.  It’s part of the Healthy Building special issue from the Journal of Exposure Science & Environmental Epidemiology.  It was led by undergrad (now post-bac) Patrick Horve and Sue Ishaq acted as managing author.

Building upon current knowledge and techniques of indoor microbiology to construct the next era of theory into microorganisms, health, and the built environment. Patrick F. Horve, Savanna Lloyd, Gwynne A. Mhuireach, Leslie Dietz, Mark Fretz, Georgia MacCrone, Kevin Van Den Wymelenberg & Suzanne L. Ishaq.  Journal of Exposure Science & Environmental Epidemiology (2019) 

Abstract

In the constructed habitat in which we spend up to 90% of our time, architectural design influences occupants’ behavioral patterns, interactions with objects, surfaces, rituals, the outside environment, and each other. Within this built environment, human behavior and building design contribute to the accrual and dispersal of microorganisms; it is a collection of fomites that transfer microorganisms; reservoirs that collect biomass; structures that induce human or air movement patterns; and space types that encourage proximity or isolation between humans whose personal microbial clouds disperse cells into buildings. There have been recent calls to incorporate building microbiology into occupant health and exposure research and standards, yet the built environment is largely viewed as a repository for microorganisms which are to be eliminated, instead of a habitat which is inexorably linked to the microbial influences of building inhabitants. Health sectors have re-evaluated the role of microorganisms in health, incorporating microorganisms into prevention and treatment protocols, yet no paradigm shift has occurred with respect to microbiology of the built environment, despite calls to do so. Technological and logistical constraints often preclude our ability to link health outcomes to indoor microbiology, yet sufficient study exists to inform the theory and implementation of the next era of research and intervention in the built environment. This review presents built environment characteristics in relation to human health and disease, explores some of the current experimental strategies and interventions which explore health in the built environment, and discusses an emerging model for fostering indoor microbiology rather than fearing it.

Recently, Dr. Gwynne Mhuireach published one of the chapters from her dissertation, on evaluating bacteria found in air from vegetated or paved areas in an urban setting!

Mhuireach, G.Á., Betancourt-Román, C.M., Green, J.L., Johnson B.R. 2019. Spatiotemporal controls on the urban aerobiome. Frontiers in Ecology and Evolution 7:43. https://doi.org/10.3389/fevo.2019.00043

Abstract:

Greater exposure to environmental microorganisms has been hypothesized to reduce the likelihood of developing autoimmune disorders, and vegetation is known to be a source of diverse microbiota to the air. However, the spatiotemporal dynamics of airborne microbial communities in urban environments with varying amounts and types of vegetation are poorly understood. In this study we used high-throughput sequencing of the bacterial 16S rRNA gene to assess whether fine-scale variation in urban vegetation influences the diversity, composition, or structure of airborne bacterial communities over time. We used passive settling dishes to collect airborne bacteria from 36 sites representing three urban land cover types (forest, grassland, paved) over a 3-month period in Eugene-Springfield, Oregon, USA. We used remote sensing data (aerial 4-band orthoimagery and LiDAR) and geographic information systems (GIS) to assess detailed site characteristics (e.g., total vegetation cover and structural diversity) for each site. Our initial analysis indicated that site was the most important factor explaining variation in bacterial community structure (R² = 0.32, p < 0.001), followed by sampling date (R² = 0.24, p < 0.001), while land cover type was a significant but weak predictor (R² = 0.06, p < 0.001) and other vegetation metrics were even less predictive. However, when samples were analyzed separately by date, the explanatory power of land cover type increased substantially; six of nine dates showed significant effects (p < 0.05) with R² ranging from 0.16–0.31, indicating that land cover type had a marked influence on bacterial community structure that was obscured by the effects of site and sampling date. Despite the importance of site as a predictor of bacterial community structure, Mantel tests for spatial correlation were insignificant for most sampling dates, suggesting that localized site characteristics were driving this relationship. We use our results to propose a space-time conceptual model of the interactions between site-scale environmental features (e.g., vegetation characteristics) and regional-scale temporal processes and events (e.g., agricultural harvesting) to understand and perhaps manage intraurban airborne bacterial communities.