About EPA's Draft Site-wide

United States
Environmental Protection
Agency

Human Health Risk Assessment



Libby Asbestos Superfund Site, Libby, Montana

December 2014

The U.S. Environmental Protection Agency (EPA) has completed its
rigorous scientific review of toxicity values and a draft human health
risk assessment specific to the Libby Asbestos Superfund Site. EPA
has prepared this fact sheet to serve as a summary of the draft risk
assessment.

1.	EPA has Significantly Reduced Risk from Exposure
to Asbestos

EPA has removed major sources of Libby Amphibole (LA) asbestos in
and around Libby and Troy. We have investigated thousands of
properties and conducted removals at more than 2,000 private
homes and properties. Removals include the former export plant,
former screening plant, boat ramp, rail yard, golf course, flyway
properties, schools and school yards, historic Hotel Libby, creek beds
and other public areas. EPA has now removed more than one
million cubic yards of impacted soil.

2.	It is Now Possible to Live and Work in Libby
Without Excessive Exposure to Asbestos

Our risk assessment shows that EPA's indoor and outdoor cleanups
have been effective in reducing both cancer and non-cancer risks in
Libby and Troy. This means that EPA's cleanup work results in
acceptable risk levels. EPA has extensively tested outdoor air in
Libby and Troy for LA asbestos and concentrations are now
equivalent to those found in other Montana cities. Air asbestos
concentrations today are up to 100,000 TIMES LOWER than when
the mine and processing facilities were operating. Higher levels of
LA could be found at some properties where owners have not yet
provided access and in areas located near the former vermiculite
mine. If you have not yet participated in EPA's cleanup, we hope
you will contact our Libby Information Office, 406-293-6194, to
schedule a property inspection.

3.	Remaining Asbestos Needs to be Safely Managed

It is not possible to remove all LA in Libby and Troy. LA is naturally-
occurring in this area. In addition, LA that is sealed behind indoor
walls or outdoors below the surface does not pose a health risk
unless it is disturbed. Ensuring that LA does not present a risk in the
future will be part of a long-term plan for the site. EPA and the
Montana Department of Environmental Protection (MDEQ) are
confident that any remaining contamination can be effectively
managed, and the selected remedy will include details on how any
waste that is left in place will be managed after cleanup is
completed.

Past, Present, and Future Risk

Past (before EPA Removals)

¦	Significant and uncontrolled sources of LA
were found across Libby and Troy due to
mining and processing of vermiculite that
was contaminated with Libby Amphibole
asbestos and the widespread use of this
mineral in homes, yards, gardens and public
places.

¦	LA asbestos from these sources was easily
disturbed and mixed in the air.

¦ Inhalation of LA asbestos from these
multiple sources presented unacceptable
risks and caused significant health hazards.

Present

¦	The most significant sources of LA
asbestos have been removed. Some LA
asbestos remains but is inaccessible
(either buried or sealed behind walls at
some properties EPA has addressed).

¦	If you have not yet participated in EPA's
cleanup, please contact the Libby
Information Office at 406-293-6194.

¦	It is now possible to live and work in
Libby and Troy without unacceptable risk
from asbestos exposure.

Future (After Remedy is Complete)

¦ Management plans will be developed to
ensure that LA asbestos is managed
effectively to protect the remedy and
the citizens and Libby and Troy.


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4.	There are Two Primary Pathways for Exposure to
LA Asbestos

Inhalation and ingestion are the two primary ways that people are
exposed to LA asbestos. Inhalation carries the greatest risk.
Interrupting this exposure pathway is essential to managing risk from
LA asbestos. In other words, the way to avoid potential health risks
from LA asbestos is to prevent inhalation of the fibers.

5.	Risk Management Will be Based on a Combination
of Factors - Not a Single Number

Because exposure is associated with dust generation, remedial action
objectives will focus on managing source concentrations as well as
activities and their locations. For example, higher risks are currently
associated with significant soil excavation and soil dust generation or
hiking in areas with elevated concentrations of LA asbestos. Risks are
also elevated for career contractors working in areas with vermiculite.

How EPA Determines Risk

1.	Develop a Site Conceptual Model

How are people exposed?

With the help of the community, EPA has
developed a model describing where
contamination is found and how people can
be exposed.

2.	Determine Exposure Parameters

What is the duration and frequency of
exposure?

EPA has studied what local residents do and
how often they engage in activities
throughout their lifetime.

3.	Determine Exposure Point
Concentrations

What are the concentrations that people
are exposed to in soil, air, etc. ?

EPA has collected over 4,000 samples in
Libby and Troy to determine the
concentrations of LA in the environment.

4.	Assess the Toxicity of LA Asbestos

What are the adverse effects from
exposure?

EPA has developed toxicity values
specifically for LA asbestos.

5.	Calculate Risk

What are the cancer and non-cancer risks?
Using the information above, EPA calculates
cancer and non-cancer risk estimates.

What's Next?

EPA issues a
Remedial
Investigation and
Feasibility Study

These reports describe the
nature and extent of site
contamination and evaluate
alternatives for cleanup.



\

EPA develops

V

preferred

1

alternatives for .

cleanup

A



V

proposed plan
y that presents
preferred
alternatives

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91



Public



comment



period



V

EPA evaluates public
comment and produces
record of decision (ROD)

EPA issues
> the ROD
for cleanup

Questions?

We are available to answer questions about the risk assessment. Please contact:

¦	Rebecca Thomas, EPA Project Manager, 1-800-227-8917 (ext. 312-6552) thomas.rebeccaffiepa.gov

¦	Jennifer Lane, EPA Community Involvement Coordinator, 1-800-227-8917 (ext. 312-6813) lane.ienniferffiepa.gov

¦	Mike Cirian/Libby Information Office, 406-293-6194, cirian.mike(5)epa.gov


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