There are a number of areas in which further research
could reduce the uncertainties and limit the variabilitiesin this study. Among these are three areas that offer an
opportunity for the most useful research. First, there is a
need to conduct a more extensive characterization of the
distribution of exposures within given population
groups. This would require the collection of more detailed
information on the characterization of occupation
probabilities, PAH uptake in the lung and skin, and daily
working logs. It would be useful to characterize better the
distribution of exposures by age of individuals exposed.
Second, there is a need for global sensitivity analysis
using the Monte Carlo simulation model with the more
detailed data sets as inputs. The ranges and distributions
of parameters can then be combined by use of the Monte
Carlo simulation model to produce a response surface.
Relationships between the input ranges and model output
should then be assessed with stepwise regression in
order to identify the relationship between output variability
and input uncertainties and variabilities. Finally,
on the basis of the results of the sensitivity analysis,
research should be directed to those parameters that, if
better characterized, could most effectively reduce variability
in the results.