Computer Modeling in Risk Assessment
There are many computer models available to aid you assess risk. The EPA has many available over the web, others by mail. The DoE had several on the RAIS web site you visited. All models have the GIGO limitation. GIGO stands for garbage in, garbage out. Beside that, which is always true, all models have their limitations. Some limitations are obvious, others are not.
We will work the rest of the semester with the RISC model. It is very user-friendly and describes many processes quite well. The developers of the model refer to it as a "screening" model. That is, it gives approximate answers quickly, and that enables you to decide what further investigations are needed to firm up your conclusions.
For this week I want you to download the files and put them on your computer and "play" with the program. The program is in three files. When you click on the File 1 below, your browser should prompt you for the location you want the file stored (don't open it yet). I suggest you store it on your desktop. After you have all three on the desktop, click on the first file, and the program should load into a folder on your C drive. You can then start the program from the Programs Folder on the Start Menu. There is an icon, that looks like a little gas pump, that you can pull onto your desktop. If you don't have your own computer, you can download the files again, or try to store the three files on a zip disk. The program is copyrighted, so please don't send it to people without getting approval. (I'll tell you more about that.) The program comes with a pdf manual, but that is not available yet. The Help function has most of the information you will need to get started.
I got a new computer and the vendor loaded Windows 2000 on it. I lost 4 days trying to get everything working again. I had to reload all my programs and manipulate data files. A mess. Besides engaging in a little whining, I noted that the RISC program seemed to work fine on my old Windows 98 operating system, but on the Windows 2000, certain functions on RISC did not seem to work. One of those is the Help button. Bummer. However, when I found the help file itself (Risc95) using Explorer , I could double click it and the Help file opened just fine. Also the buttons on the bottom, Tier 1 and WQS did not work. We will not need those for a few weeks. Also, it may not be obvious, after you enter the data on each screen, you need to click the green arrow marked "continue" to enter the data and move to the next screen.
End of sub-module