Sunday, November 24, 2013

More Modeling Links PLUS Using OLD Models on New PCs

One of the very best things about doing a blog is the almost real-time connections with colleagues in far off places.  Without leaving my home, I can get to interact and network with some marvelous folks who can literally be anywhere.

Many of you have, no doubt, seen the material sent out at regular intervals by Andrew Cutz.    Andrew provides a real service and a recent item from him really caught my eye.   He put out a notice of a new EPA web site:  EPA-Expo-Box (A Toolbox for Exposure Assessors).   This can be found at:   It is a remarkably complete and well organized resource outlining, what appear to be, most of the EPA resources on this topic.   I drilled down a little into the page and found a page that list a bunch of exposure modeling tools developed by and for the EPA.   The page is    If you start digging into any of these and have some question, just send me an email and I will try to answer them.  If they are of general enough interest I will address them in a future blog. 
Theo Shaeffers from the Netherlands has come through again with a revised version of his website.  An excerpt from a recent email he sent to me is below: 

Hi Mike
Updated the site with more interesting freeware and moved  the Dutch texts to the end.
End paste.

This site is a “list of lists” or a compendium site with tons of resources.  If you click around on this TSAC site you may come to:  which shows all the EPA OPPT’s Exposure Assessment Tools and Models.   You will notice if you go to this page that quite a few of the models are dated well before the advent of Windows 7, 8 or 8.1.    They remain very good models but they have not been updated to specifically run on these newer operating systems.   Indeed, some of them do not run on the newer Operating Systems.

A prime example of the above became painfully obvious to me last week.  I needed to install and run the relatively user-friendly and freely available model shown within the above link entitled:  Multi- Chamber Concentration and Exposure Model (MCCEM) version 1.2 (2/2/2001) available online at:

MCCEM is a remarkable model in that is allows for the estimation of airborne concentrations in multiple compartments of a home or other compartmentalized buildings from sources in individual rooms or zones.   Given ventilation rates (or using rates from an extensive database of homes) it calculates the airborne concentrations but also the dose of persons in these compartments given their time-spent and breathing rate inputs.   It also allows for Monte Carlo uncertainty analysis while allowing the user to place people and sources in various volumes during the day to receive their exposure which the model duly calculates.   It provides output reports and a .csv file of the concentrations at each time interval for which the model is run (I typically prescribe every minute).
The MCCEM model has been around for some time and runs very well on Windows 98 and Windows XP but may encounter some compatibility issues on later version of Windows (7, 8 and 8.1).  Indeed, neither I nor my IT Guru Steven Wright ( could get it to run on Windows 8.1.   Eventually, the most effective way we found to run it on newer PCs is to first install Windows XP as a virtual machine (e.g., Oracle VM VirtualBox as a free download) on a PC running the later version of Windows and then install the MCCEM software. 

These are models  “oldies but goodies” and someday someone may update them for the new Windows operating systems but until then we are just going to have to cope.

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