Application Note

3 Fluke Corporation Airborne particle counters provide vital information for maintaining indoor air quality in healthcare facilities
AII and PE facilities provide a framework for limiting the
spread of infectious agents, but they are not foolproof.
Building design, inconsistent or inadequate operating
procedures, poor maintenance and facilities construction
and renovation projects all have the potential to cause
problems. And in any case, protective facilities are not
used for all patients.
Even the b
est air filtration and
airflow desig
n can be defeated
by inadequate maintenance or
inc
orrect operation. A slipping
fan belt on a ventilation supply
fan, for instance, could alter
the air balance in a protective
environment facility, allowing
particle-laden air from the hall-
way outside to flow in. Failure to
correctly seal off and ventilate a
construction area can send a
cloud of construction dust and
Aspergillus spores into areas
where patients are housed.
Failure to fix a leaking sink can
turn the cabinet below into a
nursery for potentially hazardous
mold.
Andrew Streifel, MPH, hospital
environment specialist at the
University of Minnesota, recalls
what happened when cost-
conscious hospital administrators
tur
ned off the fan ventilating the
spac
e over a dropped c
eiling in
an intensive care area. “That
allowed humidity to stag
nate,” he
sa
ys
. “When humidity reached
extremely high levels in the
Minnesota summer, it started
raining in the I
C
U. The water
was coming through the ceiling
g
rid and dripping on the patients
.
They stopped using four or five of
the intensive care rooms, and
diverted patients
.” The larger
c
oncern, Streifel continues, was
the possibility that the high
humidity would permit mold
g
rowth. Raising the room
temperature ab
ove the dewpoint
prov
ided a temporar
y fix, and
stopped the “rain.”
iii
Building c
onstruction and
renovation can pose particular
challenges. Disruption to the
building
’s envelope, generation
of large amounts of c
onstruction
dust and debris and the move-
ment of workers and equipment
in and out of c
ontainment zones
all present contamination threats
b
eyond the norm for a healthcare
Sources of IAQ Problems
fac
ility
. Ac
c
ording to the CD
C, “a
rec
ent asperg
illosis outbreak
among oncology patients was
attributed to depressurization of
the building housing the H
S
CT
unit while construction was
under
wa
y in an adjac
ent build
-
ing
. Unfiltered outdoor air flowed
into the building through doors
and w
indow
s, exposing patients
in the H
SCT unit to fungal spores.
iv