Our findings support the following
conclusions: a) mathematical models for
predicting ETS in indoor settings have a
long history of development, with derivations
based on the underlying physical
theory of the process involved-conservation
of mass-and with experimental
results confirming the validity of the predictions
of the models; b) the models have
similar structures because all are based on
the same physical law of conservation of
mass; c) the concentrations predicted by
the models agree well with measured values
in real settings, both on a minute-byminute
(sequential time series) basis and
for longer term averages; and d) the models
are especially useful for determining the ventilation parameters required to
meet indoor air quality standards for
given smoking activity levels.
To illustrate application of the model, a
table is included to calculate the indoor
RSP concentration in any microenvironment
for which the volume and decay rate
are known. These models offer a practical,
easy-to-apply methodology with acceptable
accuracy for estimating the concentrations
in indoor settings caused by indoor smoking
activity. If one seeks to achieve adequate
indoor air quality by maintaining
pollutant concentrations below certain air
quality standards for a given mixing volume
and smoking activity, then such a model
allows one to determine the minimum
effective fresh air exchange rate that will be
required of the ventilation system. One way
to achieve desirable indoor air quality is by
adopting indoor air quality standardsconcentration
levels indoors that should not
be exceeded by indoor smoking areas-and
to establish parameters that will meet these
standards. In the absence of specific indoor
air quality standards, it is reasonable to
apply the NAAQS adopted by the U.S.
EPA as guidelines for indoor settings. These
mathematical ETS models allow one to
predict concentrations that can be compared
directly with these standards. These
indoor modeling approaches are general in
that they apply to any indoor location in
which the ACS, volume, and air exchange
rate are known or can be estimated. They
also are useful for the engineering design of
specialized smoking facilities and indoor
lounges. The models have great potential for assisting building designers and public health specialists in achieving and maintaining
adequate levels of indoor air quality in a scientifically valid manner. Although
follow-up measurements could be undertaken
to assess indoor air quality levels in
such settings, the models have performed so
well in our experiments with real smokers
in real settings that such measurements