Environmental Engineering Reference
In-Depth Information
description of the building/work environment; (5) nature of ventilation sys-
tem management; (6) previous investigations/environmental testing and
their results; and (7) any manager/owner interview/complaint documenta-
tion. Depending on the information obtained in this preliminary phase, the
investigator may develop one or more prospective hypotheses as to potential
causes of reported complaints. Such information may be used to plan the
investigation and determine environmental sampling needs.
Pre-site-visit information gathering may be used to provide building
managers with problem-solving recommendations on a self-help basis (as is
done by NIOSH staff in their investigative protocol). Of particular impor-
tance is whether the ventilation system is being operated properly and
whether thermal comfort needs are being addressed.
Pre-site-visit information gathering can be conducted systematically
with note-taking or by using a checklist. A checklist is a valuable tool, lest
the investigator fail to request desired information before the site visit.
The on-site investigation is the primary
means by which IAQ/IE problems are identified and resolved. The site
investigation should include a preliminary meeting with the building man-
ager/owner and facility staff to obtain detailed information on the nature
of the problem (the building and its use and operation), and an investiga-
tor/management agreement as to the scope of the investigation.
After the initial meeting with the building manager/owner and other
personnel, the investigator should conduct a walk-through inspection to (1)
ascertain the layout of the building and the nature of activities conducted
by its occupants, and (2) identify potential sources of contaminants and
problems through sensory means. The latter may include, for example, inad-
equate ventilation (e.g., human odor, a sense of stuffiness), solvents, known
or unknown odors, excessive/inadequate air movement, and/or thermal
discomfort. The presence of identifiable odors is an important tool in iden-
tifying potential causes of occupant complaints. The walk-through investi-
gation should also include a walk around the building (in less densely
urbanized areas) to identify where building intakes, loading docks, and
possible outdoor sources may be located, and to assess the potential for
entrainment and re-entry (see Chapter 11).
During the walk-through inspection, the investigator attempts to iden-
tify potential contaminant sources that may be responsible for the reported
problem(s). Source assessments are of a qualitative nature. Contami-
nant/source problems may have been identified in previous investigations,
known from experience, drawn from the reports of others, or have been the
subject of intensive research investigations. As a consequence, investigators
should have a sense of the kind of indoor environment/health complaints
and other problems that could occur in a building and how such problems
should be evaluated. What one considers to be a problem will, of course,
significantly affect the outcome of an investigation.
b.
On-site investigation.
