anthropogenic 284 terrestrial 279 built environment 278 air 69 host-associated 63 animal host 63 mammalian host 60 human host 60 industrialized 55 skin 52 elderly 37 adult 13 digestive tract 11 intestine 8 child 5 rural 3 non-industrialized 3 airways 3 urban 3 aquatic 2 hospital 2 very low temperature 1 high salinity 1 ice 1 infant 1 marine 1 adolescent 1