Considering healthy indoor environments in the development of human settlements by characterising the building indoor microbiome

Abstract

As humans we spend up to 90% of our lifes in indoor environments. Considering the rate of urbanisation in South Africa and globally, it would be prudent to consider the health quality of the indoor environments of current and future planned human settlements. The impact of the built environment (BE) on user health is widely known, with up to 15% of people contract healthcare acquired infection (HAI) in hospital environments, family members contracting tuberculosis (TB) in home environments and cost concerning workhours lost (USA). Yet we know very little of the health related characteristics of the indoor environment. An emerging field of the microbiology of the built environment (MOBE) could unlock our understanding towards future planning and design. Characterising the indoor BE requires interdisciplinary approaches that include architecture, microbiology and engineering. The methodology adopted was applied at two case study facilities. It includes microbial sampling of indoor rooms; sensor data collection for CO2 and temperature; and spatial metrics that include occupancy, people type, room function with internal flow patterns through spatial modelling. Correlation of the data sets provided identification of environmental factors that play an influential role on the microbiome of the indoor environment brought about by the typical user type. The findings indicated that the indoor biome varied seasonally and consisted of unique air and surface communities. Unique biomes were observed at a room space level, with similar communities at building typology level. The indoor built environment is dynamic, the need to extend these investigations into the residential and housing sphere is critical. The influence of building design decisions (operations, layout, planning, hardware and systems…) has a direct effect on the microbial composition and structure of the indoor built environment and consequently user health. This study presents an empirical quantitative approach to asses and determine what healthy indoor environment applicable in human settlements at large could be.