People's desire to understand the environments in which they live is a natural one. People spend most of their time in spaces and structures designed, built, and managed by humans, and it is estimated that people in developed countries now spend 90 percent of their lives indoors. As people move from homes to workplaces, traveling in cars and on transit systems, microorganisms are continually with and around them. The human-associated microbes that are shed, along with the human behaviors that affect their transport and removal, make significant contributions to the diversity of the indoor microbiome.

The characteristics of “healthy” indoor environments cannot yet be defined, nor do microbial, clinical, and building researchers yet understand how to modify features of indoor environments—such as building ventilation systems and the chemistry of building materials—in ways that would have predictable impacts on microbial communities to promote health and prevent disease. The factors that affect the environments within buildings, the ways in which building characteristics influence the composition and function of indoor microbial communities, and the ways in which these microbial communities relate to human health and well-being are extraordinarily complex and can be explored only as a dynamic, interconnected ecosystem by engaging the fields of microbial biology and ecology, chemistry, building science, and human physiology.

This report reviews what is known about the intersection of these disciplines, and how new tools may facilitate advances in understanding the ecosystem of built environments, indoor microbiomes, and effects on human health and well-being. It offers a research agenda to generate the information needed so that stakeholders with an interest in understanding the impacts of built environments will be able to make more informed decisions.

Contents

• The National Academies of SCIENCES • ENGINEERING • MEDICINE
• COMMITTEE ON MICROBIOMES OF THE BUILT ENVIRONMENT: FROM RESEARCH TO APPLICATION
• Acknowledgments
• Preface
• Acronyms and Abbreviations
• Summary
  • EFFECTS OF INDOOR MICROORGANISMS ON HUMAN HEALTH
  • OTHER EFFECTS OF MICROORGANISMS
  • RELATIONSHIP OF BUILDING CHARACTERISTICS TO INDOOR MICROBIAL COMMUNITIES
  • TOOLS THAT FACILITATE ANALYSIS
  • MOVING TOWARD PRACTICAL APPLICATION
  • VISION FOR THE FUTURE: MICROBIOME-INFORMED BUILT ENVIRONMENTS
  • RESEARCH AGENDA
• 1. Introduction
  • STUDY CHARGE
  • STUDY FOCUS AND SCOPE
  • EMERGING TOOLS THAT FACILITATE ANALYSIS
  • STUDYING THE INTERSECTION OF MICROBIAL COMMUNITIES, BUILT ENVIRONMENTS, AND HUMAN OCCUPANTS
  • PRIOR EFFORTS ON WHICH THIS REPORT BUILDS
  • ORGANIZATION OF THE REPORT
  • REFERENCES
• 2. Microorganisms in Built Environments: Impacts on Human Health
  • INFLUENCE OF BUILDING MICROBIOMES ON HUMAN HEALTH: ECOLOGIC AND BIOLOGIC PLAUSIBILITY
  • TRANSMISSION OF INFECTION IN INDOOR ENVIRONMENTS
  • DAMP INDOOR ENVIRONMENTS, INDOOR MICROBIAL EXPOSURES, AND RESPIRATORY OR ALLERGIC DISEASE OUTCOMES
  • NONAIRWAY AND NONALLERGY EFFECTS
  • BENEFICIAL EFFECTS OF MICROBES
  • SUMMARY OBSERVATIONS AND KNOWLEDGE GAPS
  • REFERENCES
• 3. The Built Environment and Microbial Communities
  • INTRODUCTION TO MICROBIAL RESERVOIRS IN COMMERCIAL AND RESIDENTIAL BUILDINGS
  • THE DIVERSITY OF BUILDINGS AND ITS IMPACT ON THEIR MICROBIOMES
  • INDOOR AIR SOURCES AND RESERVOIRS OF MICROBES
  • INDOOR WATER SOURCES AND RESERVOIRS OF MICROBES
  • BUILDING SURFACES AND RESERVOIRS OF MICROBES
  • IMPACTS OF MICROBES ON DEGRADATION OF BUILDING MATERIALS AND ENERGY USAGE
  • BUILDING CODES AND STANDARDS THAT MAY AFFECT THE MICROBIOME
  • THE INFLUENCE OF CLIMATE AND CLIMATE CHANGE ON THE BUILT ENVIRONMENT AND MICROBIAL COMMUNITIES
  • SUMMARY OBSERVATIONS AND KNOWLEDGE GAPS
  • REFERENCES
• 4. Tools for Characterizing Microbiome–Built Environment Interactions
  • THE BUILT ENVIRONMENT AS A COMPLEX EXPERIMENTAL ENVIRONMENT
  • CHARACTERIZING BUILDINGS
  • CHARACTERIZING INDOOR MICROBIAL COMMUNITIES
  • LINKING ANALYSIS OF MICROBIAL COMMUNITIES TO BUILDING CHARACTERISTICS AND HUMAN HEALTH IMPACTS
  • NEEDS FOR FUTURE PROGRESS
  • MOVING FROM RESEARCH TOWARD PRACTICE
  • SUMMARY OBSERVATIONS AND KNOWLEDGE GAPS
  • REFERENCES
• 5. Interventions in the Built Environment
  • PHYSICAL INTERVENTIONS TO REDUCE EXPOSURE TO HAZARDOUS MICROBES
  • CHEMICAL INTERVENTIONS TO REDUCE EXPOSURE TO HAZARDOUS MICROBES
  • INTERVENTIONS TO ENCOURAGE EXPOSURE TO BENEFICIAL MICROBES
  • A FRAMEWORK FOR ASSESSING BUILT ENVIRONMENT INTERVENTIONS
  • SUMMARY OBSERVATIONS AND KNOWLEDGE GAPS
  • REFERENCES
• 6. Moving Forward: A Vision for the Future and Research Agenda
  • A VISION FOR THE FUTURE OF THE FIELD: MICROBIOME-INFORMED BUILT ENVIRONMENTS
  • A RESEARCH AGENDA FOR ACHIEVING THE VISION
  • REFERENCES
• APPENDIXES
  • A. An Assessment of Molecular Characterization Tools
  • B. Study Methods
  • C. Committee Member Biographies
  • D. Glossary

Suggested citation:

National Academies of Sciences, Engineering, and Medicine. 2017. Microbiomes of the Built Environment: A Research Agenda for Indoor Microbiology, Human Health, and Buildings. Washington, DC: The National Academies Press. doi: https://doi.org/10.17226/23647.