The roles of the outdoors and occupants in contributing to a potential pan-microbiome of the built environment: a review

Table 1 Countries, and their populations, where HTS-based microbiome works of the BE have been conducted. A total of 72 studies involving HTS are included based on search terms “indoor microbiome,” “built environment microbiome,” “built environment microbiota,” and “indoor microbial community” on the NCBI database and Google Scholar (reference list available as Additional file 1). All studies were funded by the corresponding countries where the samples were collected. According to the reference list compiled, over 90 % of the world’s population live in countries where microbiome data for the BE is unavailable

Sampling location	Region	Study count^a	Population (million)^b	Reference
Austria	Europe	3	8.5	[1–3]
Canada	North America	2	35.5	[4, 5]
Finland	Europe	2	5.5	[6, 7]
France	Europe	2	66.2	[8, 9]
Germany	Europe	1	80.9	[10]
Hong Kong	Asia	2	7.2	[11, 12]
International^c	–	5	–	[13–17]
Singapore	Asia	1	5.5	[18]
South Korea	Asia	2	50.4	[19, 20]
Spain	Europe	1	46.4	[21]
Taiwan^b	Asia	1	23.4	[22]
United States	North America	50	318.9	[23–72]
Others	–	0	6,612.0

^aList of references available as Additional file 1
^bExcept for Taiwan, figures based on 2014 data from The World Bank (http://data.worldbank.org/indicator/SP.POP.TOTL). Taiwan figures based on 2014 data from IndexMundi (http://www.indexmundi.com/taiwan/demographics_profile.html)
^cStudies involving comparison of the microbiome of the BE in multiple locations and countries. All four international studies were funded by the USA

ISSN: 2049-2618