I see spectacular headlines when I am checking out of the Super Market. Indeed, spectacular headlines seem to work
for the National Enquirer so I hoped that they would work for me here.
I have literally grown old extolling the virtues and power
of Exposure Assessment Modeling for Industrial Hygienists; however, my friend
and colleague, Perry Logan tells me that what I have done is not enough. He advises that one has to mention something
many many times before it sinks in. I do
not remember how many times Perry suggested but it was many more than a few
times. Also, committing to using models
is not a trivial decision without at least some considerable effort. Thus, Perry is almost certainly correct, I
have not promoted modeling enough.
I may be older but I am not done and I am going to list some
of the very basic, with some self-serving, reasons an IH should get into
learning exposure modeling:
It will definitely enhance your standing with
your employer and/or your clients
You will present yourself as “one of the few” a relatively rare professional who can take
the factors that cause and predict exposure and apply them in a systematic
manner to rendering predictions of exposure and risk. This often occurs without the need for a lot
of data which managers seem to particularly like.
Indeed, many people see models as technological magic and
those who use them as wizards. It often
does not hurt you or your career to subtly let them think this is so even while
you might tell them otherwise.
. You will have confidence born of the knowledge
and ability that you personally gained to estimate exposures using models and
no one can take that from you.
These models are, for the most part, made up of first
principles; that is, basic laws of
nature like the conservation of mass and are therefore, pretty true and useful
on their face. Clearly they can be both wrong and misused but at their core they are aimed at being reasoned and reasonable
descriptors of reality or at least the reality that we know. If they fall short, then they provide a
mechanism and framework to fix themselves.
They can become complicated but they can also be “pulled apart” so that their
pieces can be examined individually as to whether they make sense.
Complex mathematical operations are no longer an
issue with available free software.
I am prone to math
errors. Running long strings of
calculations invariably has led me to make simple mistakes and the wrong answers. In order to save my credibility I learned
early on in my career that programing the calculation steps into a spreadsheet
or BASIC program took more time initially but assured I had a tool that would
not produce math errors. That early
effort has grown dramatically with other talented colleagues (like Tom Armstrong and Daniel
Drolet) taking up the cause and the result is IH MOD – which is a free Excel
Spreadsheet with mostly any modeling calculation you might need.
Like any other skill (or Rome) Modeling Acumen
will not be built in a day but the inputs can be structured to be very simple
at first and then build on themselves.
Simple models can be learned in a day (or even less than an
hour) but they are typically less useful than more complicated models; however,
they have some use and, most important, they form the basis for building your
knowledge, background, comfort level and skill base in this critical area. How many times have you climbed a long hill
(or task) one step at a time only to look back after a time to appreciate how
far you have come?
If you go back through this blog to earlier entries you can
hopefully see this progression. Start with an equilibrium model and build from
there. Perhaps the simplest model I
know is the equilibrium model: C = G/Q or
concentration (C) is equal to generation rate (G) of a contaminant divided by
ventilation rate (Q). If you do not understand this model, PLEASE
write to me and let me know where you get lost. I will put together a brief blog that goes
into enough detail to explain it. Once
you have this model, we will move on to more complicated models but I need your
help to give me feedback via email (mjayjock@gmail.com)
as to whether the lessons are working or not and if not where you get lost.
If any
of you are willing start this journey, I am willing to teach you in short 10-20
minutes blogs.
I cannot think of anything that has helped my career more
than an interest and understanding of exposure assessment models.
