Most of the concerns for non-industrial indoor environments have been focused upon commercial office facilities. From an overall health standpoint, a sizable number of people spend a majority of their waking hours in these indoor environments. Close contact with large numbers of people, centralized ventilation systems controlling large indoor environmental zones, and an overall high population density in what is essentially an enclosed box have all made the commercial office building the classic "sick building" candidate.
ASHRAE's definition of an acceptable indoor environment is one in which 80% of the occupants are comfortable and do not express complaints about the indoor environmental conditions. By the very nature of an office environment and the normal stresses of work, the numbers would seem to dictate that there will frequently be complaints about the indoor environment, even in the absence of potential microbial pollutant sources from water intrusion and/or high humidity.