Environmental Engineering Reference
In-Depth Information
indirect evidence that humans produce such gases as ammonia, methane,
hydrogen sulfide, and compounds that have pheromonal properties.
It is conventional wisdom among IAQ/IE investigators that there is a
relationship between bioeffluent levels and human comfort. This belief or
perception is based on personal experience in conducting investigations of
high-occupant-density, poorly ventilated buildings. Such environments
“feel” oppressive, with even a sense of nasal astringency.
Despite these perceptions, systematic building studies have been unable
to establish a relationship between CO
levels (the most abundant bioefflu-
ent) and illness symptoms. Several studies, however, have observed rela-
tionships between perceived air quality and CO
2
. It appears that bioeffluents,
2
as reflected in CO
concentrations in buildings, are related more to odor and
comfort concerns than health effects.
Scientific evidence to support a causal association between human bio-
effluents and comfort, and possibly health effects, is limited. There are,
nevertheless, biologically plausible mechanisms to explain why bioeffluents
may contribute to such effects. Exposure to human pheromones is suggested
here as a potential contributing factor.
Pheromones are volatile or semivolatile substances produced by animals
to elicit specific behavioral responses in individuals of the same species. In
many cases, these are associated with sexual behavior and reproduction.
Pheromonal effects have been reported to be nearly universal in social ani-
mals, including primates. Typically, male odors/scents in such species serve
to mark territory, assert dominance, repel rivals, attract females, and syn-
chronize female sexual cycles. Synchrony of female menstrual cycles is the
best known pheromonal response in humans. Experimental studies with the
putative male pheromones, androstenol and androstenone, found in male
sweat, urine, and semen, have shown that they stimulate avoidance behavior
among males, and attraction of females. The avoidance response in males
may play a spacing function. In a poorly ventilated space with high male
density, pheromonal concentrations would be expected to be relatively high,
with little opportunity to elicit pheromonally induced behavior. It has been
proposed that such a sensory overload may be responsible for symptoms of
headache and fatigue commonly reported in poorly ventilated buildings.
However, studies are needed to confirm the presence of pheromones in
indoor air, assess the relationship between occupant density and ventilation,
and determine whether they may cause symptoms because normal phero-
monally induced behavior cannot be expressed. Females produce different
pheromones than males; at present, little is known of their structure and
potential to cause behavioral effects.
2
2.
Dust
Though concentrations of particulate-phase matter are rarely assessed in
problem building investigations, there is increasing evidence that exposure
to airborne dust, or dust on interior building surfaces, is a risk factor for
