United States
Environmental
Protection Agency
Office of Solid Waste and
Emergency Response
(5204G)
EPA 540-K-98-004
OSWER9200.2-26J
PB98-963254
April 1999
SEPA
Suoerfund Toda
:OCUS ON RISK ASSESSMENT: INVOLVING THE COMMUNI
What is Human Health Risk Assessment?
This Issue...
/ Explains Superfund's
human health risk
assessment
process
/ Discusses your
participation in the
risk assessment
process
/ Gives you some tips
for getting involved
/ Provides sources
you can go to for
more information
and help
How dangerous is that Superfund site
near you? Past activities at the site,
such as wood treating, metal plating,
dry cleaning, or waste disposal may
have left hazardous substances in the buildings
or soil. In many cases, these substances have
moved into the ground water, surface water, or
air. Every time you come into contact with
these substances you face some risk.
Risk assessment is the process of estimating
how dangerous a particular situation is.
Superfund's risk assessors seek to determine
whether the hazardous substances at a site
present a dangerto you and your family. They
also do separate studies to evaluate threats to
the environment. Therefore it is importantthat
they have as much information about the site
as possible. You and other people who live
and work near the site may have important
knowledge and insights to share that can help
the risk assessors. Your involvement is useful
throughout the risk assessment, but it is most
helpful early in the process. The notepad to the
right shows some of the information you may
have.
Each Superfund site is unique, so risk
assessments are done on a site-by-site basis.
The risk assessment estimates the current and
possible future risks to your health from the
site. The goal is to understand what levels of
cleanup will be necessary to make sure you
and your family are protected. The site manager
uses the information provided by the risk
assessors to choose a good cleanup strategy.
Living near a Superfund site doesn't mean
your health is threatened. The danger to you
will depend on the substances present and the
ways you may be exposed to them. You have
a right to be informed about the possible
threats and what EPA plans to do to protect
you. The information in this issue will help
you understand how EPA measures human
health risks at Superfund sites and how you
can be involved in the process. Q
You or your neighbors
may be able to provide
information about:
1. What has gone on at
or around the site
2. Possible ways people
can be exposed to
hazards at the site
3. Who is likely to be
exposed to material
from the site
4. Community concerns,
cultures, and values
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Superfund Today • Risk Assessment
How Does Superfund Evaluate Risk?
human health risk assessment
estimates the "baseline risk."
IB^L This is the likelihood of health
M mproblems occurring as a result
of the hazardous substances at the site.
Risk assessors make this determination
through the following four-steps:
Step 1: Data Collection & Evaluation
Step 2: Exposure Assessment
Step 3: Toxicity Assessment
Step 4: Risk Characterization
Before beginning, the risk assessors
prepare a work plan. The work plan
identifies: 1) what data are needed; 2)
what assumptions are being made; and
3) what technical models will be used
(models are tools used to predict site
specific outcomes such as how ground
water moves away from a site or how
substances in soil become airborne).
Your input during the development of
the work plan can help the risk assessors
to better understand the circumstances at
the site and to avoid missing important
information.
Key questions riskassessors
should ask you during work
plan development:
What do you know about
how the site has been
used?
Who might be exposed
to materials from the site?
How might people be
exposed? for example:
fishing, gardening,
playing
What are your concerns
about dangers posed by
the site?
Some datamay already be available from
the first inve stigation of the site. The se
data are supplemented by more samples
of soil, air, water, sediment, plants, fish
and/or animals as described in the work
plan. The samples are analyzed in
laboratories to reveal the types and levels
of hazardous substances present. The
samples collected are directly related to
what the risk assessors understand to be
the problems. This is why your input is
so important. When the samples are
analyzed, hundreds of substances may
be detected. Some of these chemicals are
naturally occurring or are present at levels
that will not cause harm. Riskassessors
identify those substances which could
pose a danger to your well-being. These
are called "chemicals of potential
concern."
Key questions riskassessors
should ask you about data
collection and evaluation:
What are the current and
future uses of the site?
Are you concerned about
specific hazardous
substances?
On which parts of the site
are hazardous substances
most likely to be found?
Do you have suggestions
about the best times to
conduct sampling?
Do you have questions
about how samples are
collected and analyzed?
Exposure
Assessment
Data Collection
& Evaluation
The collection of adequate and
appropriate data is critical for evaluating
the potential risks posed by the site.
After the risk assessors have the results
of the data analysis, they look atthe ways
you might be exposed to any chemicals
of potential concern. You may come into
contact with them in a variety of ways:
breathing, touching, or consuming
contaminated air, water, soil, or food.
For each of these "exposure pathways,"
the risk assessors estimate quantities
that could reach a person's lungs,
digestive system, or skin.
Using this information, risk assessors
calculate the "Reasonable Maximum
Exposure (RME)." The RME is the
highest level of human exposure to the
substances that is likely to occur.
Exposures are calculated for different
groups of people, such as children, site
workers, residents, and the elderly. The
calculations take into account how long,
how often, and in how many ways people
could be exposed to the hazardous
substances. The RME also factors in the
number of years exposure could occur if
the site were not cleaned up. Both
current and likely future uses for the site
are considered. The exposure assessment
gives the risk assessors information about
who is vulnerable to the substancesthatare
present.
During this step you can contribute
information about behaviors and
activities that could lead to increased
risk of exposure.
Key questions riskassessors
should ask you about
exposure assessment:
Who may come in contact
with the site? for example:
children, the elderly,
pregnantand nursing
women, peoplewith
chronic illnesses
How do people use
the site? for example:
fishing, gardening,
hunting
Where are children
likely to play or trespass?
How often are people
exposed?
What types of animals
are hunted?
Do people fish here?
Do people garden or
gather food from the site?
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Superfund Today • Risk Assessment
Toxicity
Assessment
While the exposure assessment is
underway, the risk assessors are also
looking atthetoxicity, orharmfulness, of
each chemical of potential concern. They
want to determine what kind of health
effects may result from various levels of
exposure to the hazardous substances at
the site. Risk assessors usually do not do
their own toxicity testing, but rely on
previous scientific studies of the effects
of the substances on animals and, when
available, on humans. They evaluate
both the cancer and non-cancer effects
for each substance, if enough scientific
data exist.
The likelihood of some cancer resulting
from a Superfund site is expressed as a
probability; for example, a "1 in 10,000
chance" (sometimes expressed as lxlO~4
or le-04). This means that for every
10,000 people exposed to the RME, one
extra cancer may occur, beyond what
would be expected from all other sources.
Non-cancer health effects can range from
rashes, eye irritation, and breathing
difficulties to organ damage, birth defects,
and death. Risk assessors calculate the
level of exposure above which non-cancer
health effects begin to occur (this is called
the "hazard quotient").
Community input during the toxicity
assessment is limited because it is a very
technical, science-based process. You
should tell the risk assessors about any
concerns you have about potential health
effects. This will help them give you clear
explanations of the conclusions they are
reaching about possible health hazards.
Key questions riskassessors
should ask you about the
toxicity assessment:
Have you discussed any
unusual health problems with
local public health officials?
What do you not understand
about the toxicity assessment
process or the results?
Risk
Characterization
Finally, the risk assessors combine the
results of the first three steps and come up
with their estimate of the risks posed by the
site. Thisisknownas"riskcharacterization."
In reaching their conclusions they take into
account the type s and amounts ofhazardous
substances present, the ways in which
people are exposed, and the effects of the
substances on human health. The risk
assessors are very careful to make sure
Risk Assessment
Data Collection &
Evaluation
2 Exposure Assessment
3 Toxicity Assessment
4 Risk Characterization
Cleanup Decision
their work will not lead to results that
understate the level of threat posed by
the site. Theirresults will be used bythe
site manager, who decides what cleanup
actions must be taken to protect you and
your family. During this last part of the
risk assessment, the risk assessors should
provide you with a clear explanation of
what their conclusions mean for your
health.
Key questions riskassessors
should ask you during risk
characterization:
Haveyourconcerns been
adequately answered?
Do you believe any
substances, kinds of
exposure, or any
vulnerable persons
have been missed?
Do you understand
the results of the risk
assessment? Q
ATSDR's Role
in Risk
Assessment
The Agency for Toxic
Substances and Disease
Registry (ATSDR) is part of
the U.S. Public Health
Service. ATSDR may conduct a
Superfund public health assessment,
which is an independent evaluation of
whether exposure to a site poses a
danger to the people who live and work
near it. This helps to ensure that EPA
doe s not overlook or undere stimate any
threats. Both a human health risk
assessment and a public health
assessment study overall hazardous
substance threats to people. Neither is
a substitute for apersonal medical exam
to determine your own health status.
To find out more about public health
assessments, call ATSDR toll-free at:
1-800-442-8737. Q
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Superfund Today • Risk Assessment
How The Risk
Assessment
Results Are Used
The risk assessors explain their conclusion to the managers
responsible for cleaning up the site. The risk assessment
is just one of the things the managers look at when
deciding what actions must be taken to protect your
health and welfare. Other things that play a role in the decision are
state and federal regulations, technology alternatives, costs, and
community acceptance. If the level of risk is low, the site managers
may decide that some or all of the substances may remain safely at
the site. Sometimes cleanup workers can simply put a cap overthe
site or build underground walls to keep hazardous substances from
reaching you or others. The site manager's goal always is to keep
the community safe. Until all site actions are completed, workers
continue to check the conditions to make sure that you are not in any
danger. Q
EMEMBER...
Your input to the risk assessment is
important. You need to realize, however,
that risk assessors must follow certain
regulations and technical procedures. While
all your concerns will be considered, the risk
assessors may not always be able to do all
of the things you want. But they should be
responsive and give you clear explanations
for what they are or are not doing.
Risk assessment is not an exact science.
Risk assessors use the best available data
on what is occurring, or could occur, at the
site. They apply their scientific judgment to
calculate the likelihood of exposure to
hazardous substances and the health
consequences of such exposure. While the
results are probabilities, not certainties, the
risk assessors are careful not to
underestimate any threats. The risk
assessment is one of many inputs to the
decision of how to protect your health and
welfare, a
I ips for
Gatiincj
Involved
How Do I Get Started?
Seek out and talk to the risk
assessors about becoming
involved in the process.
Review the key questions in this
document and begin to think how
you will answer them.
What Should I Keep In Mind?
Be Prepared...
To be involved in a meaningful
way you must make some
commitment of time and energy.
You can prepare by:
1) Learning about the risk
assessment process and the
site history;
2) Participating in meetings and
talking with risk assessors; and
3) Following up on key issues.
Take Initiative...
Lookforwaystogetinvolved. Raise
concerns in a constructive manner
and contributefully and responsibly
during the risk assessment.
Ask Questions...
Don't be afraid to say you don't
understand something. Be sure to
ask for clarification of technical
concepts.
Recognize Constraints...
The Superfund law and
accompanying policies and
regulations establish a framework
within which the risk assessment
and all other activities must be
conducted. There are also
professional and technical
guidelines and funding restrictions
that affect what risk assessors
can do. a
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Superfund Today • Risk Assessment
The Rest of the Story:
Superfund Cleanups
PA uses the results of a risk assessment to help decide whether any long-term cleanup is needed at a Superfund
site. If the answer is "yes," the risk assessment also guides decisions on the type of remedy and cleanup levels that
would protectyour health and the environment. Afterthe risk assessment, EPA continues to seek your opinions on proposed
cleanup approaches, which are thoroughly investigated before any decision is made.
There are two basic types of cleanup technologies in use at Superfund sites: treatment and containment. Treatment technologies
use engineering approaches to reduce the amount of hazardous substances present, their ability to move off the site, or the hazard
they present. Treatmenttechnologies include destroying substances by burning them at high temperatures while controlling the
fumes; allowing substances to evaporate into an air stream that is then treated and released; and injecting soils with micro-
organisms that digest substances and result in less harmful materials. Containment approaches build barriers that isolate
hazardous substances and keep them from coming into contact with people and the environment. Containment technologies
include constructing a protective barrier, or cap, over the contaminated area; excavating the substances and disposing of them
in a securely designed landfill; and building an underground barrier that blocks, diverts, or captures polluted ground water.
In many cases, a combination of treatment and containment is the best solution. Engineers design the long-term cleanup
approach. As cleanup work progresses, the levels of the hazardous substances are constantly measured to make sure the cleanup
goals are being achieved and that there is no immediate danger to you. If chemical materials are left at a site, EPA re-examines
the site every five years after cleanup to make sure it is still safe. Q
IVIOTG • • • on EPA's risk assessment process, or about a Superfund site in your
neighborhood, please contact the toll-free Superfund/RCRA Hotline at 1-800-424-9346 orthe Community Involvement
Coordinator in the EPA regional office for your state; their numbers are listed below. Your local EPA office can tell you
where you can go to review files on every Superfund site in your area. This information may include the results of a risk
assessment. Often, EPA conducts community meetings to keep people who live near a site informed about site activities.
You may also find useful information on the Superfund home page (www.epa.gov/superfund) underthe Community Tools
and Technical Resources subheadings. Q
Region 1 - CT, ME, MA, NH, Rl, VT
JFK Federal Building , Room RPS-74
Boston, MA 02203
(617) 565-3425 or (888) 372-7341
Region 2 - NJ, NY, Puerto Rico, Virgin Islands
290 Broadway St.,
New York, NY 10007
(212) 637-3671 or (800) 346-5009
Region 3 - DE, DC, MD, PA, VA, WV
1650 Arch St.,
Philadelphia, PA 19103
(215) 814-3245 or (800) 553-2509
Region 4 - AL, FL, GA, KY, MS, NC, SC, TN
Waste Management Division, Atlanta,
Federal Center, 61 Forsyth St.,
Atlanta, GA 30303
AL, FL, GA, MS (800) 435-9234
KY, NC, SC, TN (800) 435-9233
Region 5 - IL, IN, Ml, MN, OH, Wl
Metcalfe Federal Bldg., 19th Floor,
77 West Jackson Blvd.,
Chicago, IL 60604
(312) 886-6685 or (800) 621-8431
Region 6 - AR, LA, NM, OK, TX
Tower & Fountain Place
1445 Ross Ave., 12th Floor
Dallas, TX 75202
(214) 665-8157 or (800) 533-3508
Region 7 - I A, KS, MO, NE
726 Minnesota Ave.,
Kansas City, KS 66101
(913) 551-7003 or (800) 223-0425
Region 8 - CO, MT, ND, SD, UT, WY
999 18th St., Ste. 500
Denver, CO 80202
(303) 312-6600 or (800) 227-8917
Region 9 - AZ, CA, HI, NV, U.S. Territories
75 Hawthorne St.,
San Francisco, CA 94105
(415) 744-2178 or (800) 231-3075
Region 10 - AK, ID, OR, WA
1200 6th Ave.,
Seattle, WA 98101
(206) 553-1272 or (800) 424-4372
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Superfund Today • Risk Assessment
cvEPA
United States
Environmental Protection
Agency (5204G)
Washington, DC 20460
Official Business
Penalty for Private Use
$300
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