416 Energy Project Financing: Resources and Strategies for Success
section will briefly describe two less familiar classes of building-related
health effects: acute non-specific health symptoms associated with build-
ings and building related illness (BRI). More comprehensive discussions
of the health effects associated with IEQ factors are provided in the
published literature (e.g., Gammage and Berven 1996)
4.6.1 Non-Specific Health Symptoms
The most common health symptoms attributed by building oc-
cupants to their indoor environments are non-specific health symptoms
that do not indicate a specific disease, such as irritation of eyes, nose,
and skin, headache, fatigue, chest tightness, and difficulty breathing.
These symptoms are commonly called sick building syndrome symp-
toms; however, we use the term non-specific health symptoms because
the term sick-building syndrome can be misleading (i.e., the building is
not sick and the building is not always the cause of symptoms). People
commonly experience these non-specific health symptoms; however,
their prevalence or severity varies considerably among buildings and,
in some buildings, the symptoms coincide with periods of occupancy
in the building. Buildings within which occupants experience unusu-
ally high levels of these symptoms are sometimes called sick buildings.
Some non-specific health symptoms are experienced frequently by a
substantial fraction of all office workers (e.g., Brightman et al. 1997, Fisk
et al. 1993; Nelson et al. 1995). The causes of non-specific health symp-
toms appear to be multifactorial and are not thoroughly understood.
Although psychosocial factors such as the level of job stress are known
to influence non-specific health symptoms, several characteristics of
buildings and indoor environments are also known or suspected to in-
fluence these symptoms including: the type of ventilation system, type
or existence of humidifier, rate of outside air ventilation, the chemical
and microbiological pollution in the indoor air and on indoor surfaces,
and indoor temperature and humidity (Mendell 1993; Sundell 1994).
On average, occupants of sealed air-conditioned buildings report more
symptoms than occupants of naturally ventilated buildings. Humidifiers
increase the likelihood that occupants report these symptoms possibly
because they can be a source of bioaerosols. Most studies have found
that lower indoor air temperatures are associated with fewer non-spe-
cific health symptoms. Symptoms have been reduced through practical
measures such as increased ventilation, decreased temperature, and
improved cleaning of floors and chairs (Mendell 1993).