Comprehensive Chemical Exposure Framework

Title Page

1.0 Introduction

2.0 Literature Review

3.0 Model Framework

4.0 Scenarios

5.0 Qualitative Analysis
5.1 Source/Transport
5.2 Exposure/Impact

6.0 Recommendations

7.0 References

Appendix A

5.0 Qualitative Sensitivity Analysis of CCEF Modeling Components

The purpose of this analysis was to identify the model elements (estimation algorithms and parameter databases) likely to produce the largest changes in exposure estimates obtained from the model. Given the list of existing computer models and gaps in the models needed, the next step was to rank the model elements according to their relative contribution to the resulting output.

Conducting the detailed qualitative sensitivity analyses of existing models for exposure and impact components of the four scenarios is not possible at this time due to significant lack of models available for use in these processes. This lack of adequate and/or appropriate models for use in estimating exposure and impact processes clearly points out the need for a broad range of research in this area.

The primary computer models selected for source or transport in one or more of the four scenarios evaluated for the CCEF were: CONTAM, PROMISE, IAQX, WPEM, and CONSEXPO. It was also assumed that a good model or algorithm already exists for mainstream and sidestream cigarette smoke. Data gaps have already been discussed in the gap analysis for source and transport models.

The Source and Transport Process was ranked according to the following needs:
1. Models & Databases on the primary exposure pathway were believed to introduce more sensitivity, and therefore be of higher priority, than those on secondary exposure pathways;
2. Missing models and databases were considered a higher priority research need than known models;
3. Inaccurate models were ranked as a higher priority research need than accurate models; and
4. Models were of lesser compatibility (e.g., differing time and spatial scale) with the upstream and downstream models were considered a higher priority.