Testing for PCBs in Indoor Air
Posted by Rebecca McDaniel on Mon, Dec 14, 2009 @ 06:31 AM
By Jason Atwood, Field Service Manager
In
recent months, public scrutiny surrounding the presence of PCB's in
materials commonly used in public school building construction prior to
1978 has been mounting. Media coverage and an onslaught of resulting
attention have forced this issue to the forefront of public health and
safety concerns pertaining to our environment. Typically - this focus
has been aimed at the presence of the contaminated caulking itself: in
window glazing/caulking, interior and exterior joint compounds, in
Univent construction, paints, etc.
While building inspections
and intensive sampling plans will certainly illustrate the cause of
concern (I.E. The presence of PCB contaminated material is the crux of
the issue), the true effect may not become evident without a stringent
air monitoring / sampling plan. PCBs do not become an immediate hazard
until they are ingested into the human body, be it through consumption,
absorption or inhalation.
The latter may be the issue of
greatest concern in the context of classroom hazards. PCBs have the
ability to volatilize - that is tiny particles of the material can
vaporize from the solid state and become airborne, a process that is
expedited with the presence of heat. Window caulking and glazing
subject to extended exposure to the sun, PCB ballast material that may
leak inside of fluorescent lighting and PCB containing material within
or immediately around HVAC systems all pose a significant risk for
volatilization. Once airborne, PCB particles mix with other sources of
airborne dust and can be directly inhaled, or can deposit on horizontal
surfaces and then be ingested or absorbed.
To ensure your
school department engages in a robust and encompassing risk assessment
plan, it is imperative that they focus not only on potentially impacted
materials, but also on the byproducts of those materials in the form of
airborne PCB concentrations and associated surface dusts. The EPA has
established guidelines for acceptable PCB concentrations for both of
these medias, taking into account all potential sources of human
ingestions of PCBs and how those risks align with the risks outlined
herein. These guidelines can be found here.
As
with all environmental concerns, effective assessment is essential in
the development of a risk management plan. PCBs in building materials,
air, dusts, and soil are all manageable risks that can mitigated
through effective remediation efforts. As public scrutiny surrounding
this issue has intensified, so also has our ability in the
environmental services industry to protect families from future
exposure and the resulting detrimental health effects.