August 1, 2011.
The Chemical Mixture Methodology (CMM) provides default emergency exposure guidelines for mixtures of chemicals. The CMM uses Health Code Numbers (HCNs) to assess the additive impact that each chemical component in an airborne chemical mixture may have on people located at a specified receptor location. The CMM is a more realistic predictor of potential human health impacts than can be obtained using the (1) non-conservative method of separately analyzing the consequences of each chemical component or the (2) overly-conservative method of adding the exposures from each chemical together regardless of the human organ system (e.g., eyes, lungs, nervous system) targeted by the individual chemicals (see http://orise.orau.gov/emi/scapa/chem-mixture-methodolgy/default.htm for more information). Operationally, the CMM is encapsulated into a Microsoft Excel workbook which uses macros to perform run the necessary calculations and output the health risk data. The workbook has a number of limitations, including:
- limited space for reporting HCN values
- inability to calculate and report impacts at multiple receptor locations
- limited opportunity to make timely updates to the CMM data set.
The goal of the CMM Wizard project has been to overcome many of these issues and make the CMM available in a more robust, accessible, and user-friendly format.
The first version of CMM Wizard software was developed using Visual Basic-based ASP software. That version captured the capabilities of the CMM Workbook and provided a more user-friendly interface that was accessible online. The specific goals for the second (current) version are to:
- replace the existing ASP code with ASP.NET to allow for more robust and modularized coding
- generate output for multiple receptor locations
- establish a way to store and access input data and output products by reading and writing custom CMM files
- provide the option to download output products in a digital or hardcopy format
- improve the appearance and robustness of the Wizard.
Another aspect of the development of the new version of the CMM Wizard will be laying the groundwork for an improved quality assurance program and problem reporting mechanism that will reduce the time needed to update CMM data and enhance software.
Xiao-Ying Yu, Cliff Glantz, Jeremy Rishel
Pacific Northwest National Laboratory (PNNL)
This material is based upon work supported by the S.D. Bechtel, Jr. Foundation and by the National Science Foundation under Grant No. 0952013. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the S.D. Bechtel, Jr. Foundation or the National Science Foundation.