or this month's article, I thought it
might be a good idea to go back to
some basics regarding indoor air
quality (IAQ) issues. Before I go any
further, however, I need to give a big shout-out
to my friend Mike McGuinness. It was dur-
ing a conversation that he and I had at this
year's Building Sciences Summer Camp that
he reminded me about the four Ps in IAQ. This
concept has been discussed in depth else-
where in other publications, but it never hurts to
reintroduce it from time to time.
Whenever we are dealing with building occu-
pant complaints and adverse health effects, it
is important to remember that there are a se-
ries of links in the chain of causation. For IAQ
problems that are caused by exposure to some
sort of airborne contaminant(s), the chain of
causation can be boiled down to a fairly simple
(at least on paper) equation:
Poll + Path + Pres + Peop = Prob
Where:
Poll = Pollutants
Path = Pathways
Pres = Pressures
Peop = People
Prob = Problems
That's it. There's really not all that much to
it, once you understand the principal and the
mechanisms behind it. If you can break any
one of those links in the chain, then you can
usually resolve the problem. So, with that said
let us take a closer look at the first four "Ps."
Pollutants
Pollutants come in a variety of forms. There
can be particulate pollutants, such as diesel
fumes, pollen, or smoke; vapor pollutants, such
Healthy Indoors 27
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