Embracing microbes in exposure science

Abstract

Although defined more broadly, exposure science has mainly focused on exposures to environmental chemicals and related stressors, such as airborne particulate matter. There is an opportunity for exposure science to contribute more substantially to improving public health by devoting more attention to microorganisms as key stressors and agents in exposure. The discovery that pathogenic microbes cause disease in humans precipitated a revolution in public health science and disease prevention. With a continued global urgency to address spread of pathogenic microbes, contributions of microorganisms to both infectious and noninfectious processes merit more attention from the exposure science community. Today, discoveries of the importance of the human microbiome as a determinant of health and disease are precipitating a second revolution. Emerging knowledge creates a major opportunity to expand the scope of exposure science to incorporate the human microbiome as a target and modulator of exposure. A study committee of the National Academies of Sciences, Engineering, and Medicine has defined a research strategy to address health risks that pertain to the interaction of environmental chemicals with the human microbiome. Some aspects of this strategy pose important challenges and opportunities for the exposure science community.

Building upon current knowledge and techniques of indoor microbiology to construct the next era of theory into microorganisms, health, and the built environment

“…Overall, our understanding and our views of the relationships we have with microorganisms are evolving [20,31,202,245]. What remains is the ability to know why, when, and how microorganisms transfer from the built environment to occupants, when these interactions matter, under what circumstances these transfers lead to disease, and when these interactions are beneficial to built environment occupants [33]. The variety of occupants and health needs in a space will likely dictate strategies to inform that indoor microbiome, including fostering or inhibiting human to human contact, removing or adding microbial biofilms, and integrating microbial communities into building systems.…”

“…The majority of interest in microbiology of the built environment has focused on microbially-mediated building deterioration or detriment to occupant health from specific microorganisms of interest. Despite advances in awareness of the potential for microbial exposure indoors [33], microorganisms in the built environment are still considered as debris to be removed, instead of members of a microbial ecosystem which is inexorably linked to the influences of building inhabitants [29,31,[34][35][36][37]. Given the propensity for microbial biofilms or overgrowth to pose a threat to the health of occupants, it is not difficult to understand why.…”

Endotoxin and particulate matter emitted by livestock farms and respiratory health effects in neighboring residents

“…Besides relevance of microbial emissions with respect to transmission of infectious disease, this also draws attention to non-infectious health effects (Leibler et al, 2017). Microbial air pollution is, compared to other types of air pollution, understudied (Nazaroff, 2019). Additional research is required to substantiate findings of this study, most importantly shape of the associations and effect sizes given the confidence intervals observed at the higher range of exposure.…”

Implications of indoor microbial ecology and evolution on antibiotic resistance

“…Currently in developed countries, exposure to microbes is most likely going to take place in built environments, as humans in modern societies spend nearly 90% of their lifetime indoors [1]. Given the importance of indoor air and built microenvironments on individual exposures [2], the National Academy of Sciences, Engineering, and Medicine recently outlined a research agenda to investigate "the formation and function of microbial communities in built environments and the impacts of such microbial communities on human health" [3,4]. Therefore, understanding which microbial exposures take place within the built environment and how is of primary importance to thoroughly assess risks for human health.…”