vvEPA
United States
Environmental Protection
Agency
EP A/600/R-19/161
September 2019
http://epa.gov/pprtv
Superfund Health Risk
Technical Support Center
FY 18 Annual Report
October 2017 - September 2018
National Center for Environmental Assessment
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
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"
DISCLAIMERS
This report is intended to inform the public, Remedial Project Managers, On-Scene
Coordinators, and Superfund Technology Liaisons of progress at the Superfund Health Risk
Technical Support Center (STSC) involved sites, cutting-edge approaches, and STSC operations.
This document has been reviewed by the U.S. Environmental Protection Agency, Office of
Research and Development, and approved for publication.
The views expressed in this report are those of the author(s) and do not necessarily represent the
views or policies of the U.S. Environmental Protection Agency.
Mention of company trade names or products does not constitute endorsement by the
U.S. Environmental Protection Agency and are provided as general information only.
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^ ACKNOWLEDGEMENTS
pro^°
The Superfund Health Risk Technical Support Center (STSC) is part of a core group of technical
support centers and regional forums established and maintained under the Technical Support
Project.
The STSC acknowledges the following individuals for their support in the preparation of
Provisional Peer-Reviewed Toxicity Values (PPRTVs) and STSC technical responses during the
2018 Fiscal Year:
U.S. EPA, Office of Research and Development (ORD),
National Center for Environmental Assessment (NCEA):
Chris Cubbison
Jeffiry Dean
Belinda Hawkins
Phillip Kaiser
Jason Lambert
Lucina Lizarraga
Beth Owens
Dan Petersen
Glenn Rice
Paul Reinhart
Teresa Shannon
Jeff Swart out
Michael Troyer
Scott Wesselkamper
Jay Zhao
Bette Zwayer
We would also like to express our great appreciation for the funding provided by the Office of
Land and Emergency Management, Office of Superfund Remediation and Technology
Innovation and the Human Health Risk Assessment National Research Program.
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^PRC^°
LIST OF TABLES
Table 1. PPRTVs Developed in FY2018
LIST OF FIGURES
Figure 1. Locations of ORD Technical Support Centers 1
Figure 2. Number and Description of Provisional Toxicity Values Derived in FY2018 4
Figure 3. 1951 Advertisement by Flercules Incorporated 6
Figure 4. Remedial Excavation Commercial Site Properties 7
Figure 5. Rare earth elements include the lanthanides, highlighted in blue 8
Figure 6. FY2018 STSC Ftotline Requestor Affiliation 9
Figure 7. Photo of Naval Weapons Station Earle (Site A) in Colts Neck, NJ 11
Figure 8. PFAS Foam in Michigan Water, EPA Region 5 12
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PRO^°
ABBREVIATIONS AND ACRONYMS
ATSDR Agency for Toxic Substances and Disease Registry
U.S. EPA United States Environmental Protection Agency
FY fiscal year
HEAST Health Effects Assessment Summary Tables
IRIS Integrated Risk Information System
NCEA National Center for Environmental Assessment
OLEM Office of Land and Emergency Management
ORD Office of Research and Development
OSRTI Office of Superfund Remediation and Technology Innovation
p-IUR provisional inhalation unit risk
p-OSF provisional oral slope factor
PPRTV provisional peer-reviewed toxicity value
p-RfC provisional reference concentration
p-RfD provisional reference dose
STSC Superfund Health Risk Technical Support Center
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^~PRO^-°'
INTRODUCTION
The primary goal of the Superfund Health Risk Technical Support Center (STSC) is to
provide scientific technical support in the area of human health risk assessments for the Office of
Land and Emergency Management (OLEM), state, and regional partners. The STSC is operated
by the U.S. Environmental Protection Agency (EPA or Agency) Office of Research and
Development's (ORD's) National Center for Environmental Assessment (NCEA) in Cincinnati,
Ohio.
The STSC is one of five active technical support centers (TSCs) established as part of the
Technical Support Project (TSP) partnership (Figure 1). In 1987, OLEM (formerly the Office of
Solid Waste and Emergency Response [OSWER]), Regional Superfund Office, and ORD
established the Superfund TSP to provide technical assistance to regional remedial project
managers (RPMs) and on-scene coordinators. The TSP consists of a network of regional forums,
the Environmental Response Team, and specialized TSCs.
Figure 1. Locations of ORD Technical Support Centers
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Each TSC has a specific focus of expertise and is dedicated to serving the EPA and its
clients by supplying high-quality, quick-response, technical support services for contaminated
sites. Clients of the STSC are scientific staff supporting the Superfund program. Specific clients
include EPA regional scientists and risk managers, authorized contractors, state scientists, and
others. The STSC performs two general functions to support the Superfund program:
(1) preparation and distribution of Provisional Peer-Reviewed Toxicity Value (PPRTV)
assessments and (2) scientific/technical consultations in support of states, EPA regional scientists,
and associates regarding issues related to contaminated sites. This report provides an overview of
these functions of the STSC and a selection of technical responses provided in FY2018.
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(
<
IP" STSC ACCOMPLISHMENTS
In FY2018, the STSC provided technical support through the development and
release of four PPRTV assessments and by responding to 32 technical requests
from various EPA regions, state agencies, and international requestors.
The STSC support staff tracks requests and activities, including requestor and site
information, initiation and completion dates, summaries of the requests, and hours associated with
that request. The information is compiled into an internal tracking database.
PROVISIONAL PEER-REVIEWED TOXICITY VALUE (PPRTV) ASSESSMENTS
The STSC's PPRTV Program supports the Agency's mission to protect human health and
the environment by identifying and characterizing the health hazards of chemicals of interest to
the Superfund Program. PPRTV assessments are an important source of toxicity information and
toxicity values for use by OLEM. Derivation of PPRTVs for use by OLEM is necessary when such
values are not publicly available elsewhere. PPRTV assessments provide provisional toxicity
values (e.g., provisional oral reference doses [p-RfDs], inhalation reference concentrations
[p-RfCs], and cancer risk values such as provisional oral slope factors [p-OSFs] and provisional
inhalation unit risks [p-IURs]) for subchronic or chronic exposure to chemicals. Importantly, the
information in PPRTV assessments can be used in combination with exposure metrics to
characterize the public health risks of a given substance at a particular Superfund site. These risk
characterizations can form the basis for risk-based decision making, regulatory activities, and other
risk management decisions designed to characterize and protect human health.
PPRTVs are derived after a review of the relevant scientific literature and use Agency
methodologies, practices, and guidance for the development of toxicity values. All PPRTV
assessments receive internal review by EPA scientists and external peer review by independent
scientific experts. For additional information on PPRTVs and the methodologies used, please refer
to https://www.epa.gov/pprtv. PPRTV assessments are eligible to be updated as requested by the
Agency to incorporate new data or methodologies that might impact the science and decisions used
to derive provisional toxicity values, and are revised as appropriate.
In addition, screening PPRTVs can be derived in the appendix of a PPRTV assessment
when the data do not meet all requirements for deriving a toxicity value in the main body.
Screening values can be subchronic and chronic p-RfDs and p-RfCs, as well as p-OSFs and
p-IURs. Screening PPRTVs are derived using the same methodologies and undergo the same
development and review processes (i.e., internal and external peer review, etc.) as provisional
values presented in the main body of an assessment. Users of screening PPRTVs are made aware
that there is more uncertainty associated with the derivation of these values than for values
presented in the main body of a PPRTV assessment.
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The STSC, in consultation with OLEM's Office of Superfund Remediation and
Technology Innovation (OSRTI), prioritizes candidate chemicals for PPRTV development. In
FY2018, the STSC developed four PPRTV assessments, providing the Superfund Program with
eight provisional toxicity values (Figure 2). Three of these provisional toxicity values were
developed as screening values as a result of limited data that did not meet all the requirements for
a toxicity value. Table 1 provides a list of each assessment as well as the type of value(s) derived
in each assessment.
PPRTVs are publicly available for download from the "PPRTV Assessments Electronic
Library" at https://www.epa.gov/pprtv.
Screening Chronic
p-RfD, 1
Screening
Subchronic p-RfD,
\
Subchronic p-RfD,
Chronic p-RfD, 3
Figure 2. Number and Description of Provisional Toxicity Values Derived in FY2018
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Table 1. PPRTVs Developed in FY2018
Assessment Information
Provisional Values Derived
Chemical
CASRN
New/
Update
Chronic
p-RfD
(mg/kg-d)
Subchronic
p-RfD
(mg/kg-d)
Chronic
p-RfC
(mg/m3)
Subchronic
p-RfC
(mg/m3)
p-IUR
(mg/m3)1
p-OSF
(mg/kg-d)1
WOE
Descriptorb
Soluble Gadolinium
7440-54-2
Update
NDr
4xl0"2a
NDr
NDr
NDr
NDr
Lnadequate
Soluble Lanthanum
7439-91-0
New
5xl0"5
5xl0"5
NDr
NDr
NDr
NDr
Lnadequate
Soluble Lutetium
7439-94-3
Update
NDr
4X10"1
NDr
NDr
NDr
NDr
Lnadequate
Technical Toxaphene/Weathered
Toxaphene
8001-35-2
New
9xl0-5/3xl0"5a
3xl0-4/3xl0"5a
NDr
NDr
IRIS value
cited (U.S.
EPA. 1988)
IRIS value
cited (U.S.
EPA. 1988)
Lnadequate
aDenotes a(n) screening/appendix value.
bCancer WOE descriptors according to U.S. EPA Guidelines for Carcinogen Risk Assessment (U.S. EPA. 20051 are defined as:
Carcinogenic = Carcinogenic to Humans; Likely = Likely to be Carcinogenic to Humans; Suggestive = Suggestive Evidence of Carcinogenic Potential;
Lnadequate = Lnadequate Lnformation to Assess Carcinogenic Potential; Not Likely = Not Likely to be Carcinogenic to Humans.
CASRN = Chemical Abstracts Service registry number; FY = fiscal year; IRIS = Integrated Risk Information System; NDr = not determined;
p-IUR = provisional inhalation unit risk; p-OSF = provisional oral slope factor; PPRTV = provisional peer-reviewed toxicity value; p-RfC = provisional
reference concentration; p-RfD = provisional reference dose; WOE = weight of evidence.
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The following section highlights the impact and scientific challenges addressed by a
selection of FY2018 PPRTV assessments.
PPRTVs for Technical Toxaphene, Weathered Toxaphene and Toxaphene Congeners -
EPA Region 4
Throughout the mid-1940s, technical
toxaphene was manufactured for use as an
insecticide, piscicide, and pesticide. Mainly,
toxaphene was utilized as pest control on
cotton crops but it was also found to control
pests in livestock and poultry, and other field
crops (Figure 3). U.S. EPA canceled most of
its uses in 1982 and completely canceled all
uses in 1990. Terry Creek Superfund site near
Brunswick, Georgia has been contaminated
with technical toxaphene discharged from
Hercules, Inc during its manufacturing for
over 30 years. Though the former plant no
longer produces toxaphene, toxaphene
continues to be identified in exposure samples
and questions are posed as to the potential
hazard to human health. Without toxicity
values to characterize the potential health
hazard of technical toxaphene, EPA Region 4
was unable to set risk-based remedial goals or
respond to community concerns about
exposure. These concerns led to Office of
Inspector General (OIG) recommendations on
updating analytical methods and evaluating
the risks of toxaphene exposure.
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Figure 3. 1951 Advertisement by
Hercules Incorporated
(Photo Credit: Science History Institute)
In its physical state, technical toxaphene is a waxy yellow solid and is composed of a
complex mixture of hundreds of chlorinated terpenes. Once released into the environment, the
congeners of technical toxaphene undergo transformations from abiotic and biotic processes which
results in different mixtures of toxaphene congeners known as weathered toxaphene. As no
noncancer toxicity values were publicly available for technical toxaphene, weathered toxaphene,
or individual toxaphene congeners, the Provisional Peer-Reviewed Toxicity Value assessment for
Technical Toxaphene, Weathered Toxaphene, and Toxaphene Conseners (CASRN 8001-35-2)
('EPA/690/R-18/002) was developed. This PPRTY evaluated a complex database for technical
toxaphene and derived subchronic and chronic provisional oral reference doses for technical
toxaphene. In addition, it was concluded that the limited human and animal toxicity data that exists
for weathered toxaphene and toxaphene congeners was insufficient to derive provisional oral
reference doses for these compounds. Thus, additional approaches were considered for deriving
screening provisional oral reference doses for these compounds leading to the derivation of
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screening subchronic and chronic provisional oral reference doses for weathered toxaphene based
on technical toxaphene (U.S. EPA. 2018d). This PPRTV provides a definitive assessment of the
available science regarding toxaphene, weathered toxaphene, and toxaphene congeners, which had
been an ongoing technical issue for the Region's project managers for more than a decade enabling
Region 4 to establish risk-based screening levels for soil and fish, estimate potential risks for the
ingestion pathway, and establish clean-up goals where potential risks for direct exposure via
ingestion have been determined to be unacceptable.
PPRTVs for Stable (Nonradioactive) Soluble Lanthanum - EPA Region 2
The metallic rare earth element
lanthanum naturally occurs in the earth's
crust. Lanthanum can be used during water
treatment and lanthanum salts are used in
electronic devices, pyrophoric alloys, rocket
propellants, reducing agent catalyst for
conversion of nitrogen oxides to nitrogen in
exhaust gases, and phosphors in X-ray
screens. Soluble lanthanum salts differ
substantially from insoluble salts with respect
to absorption, distribution, and
elimination in the body. Therefore, the
insoluble salts are not included in the PPRTV
assessment.
From 1916 through 1955, Maywood Figure 4. Remedial Excavation Commercial
Chemical Company processed radioactive Site Properties
thorium ore. Located in northern New Jersev, (Photo Credit: Formerly Utilized Sites Remedial Action
the chemical company generated several Program (FUSRAP) Maywood Superfund Site.)
waste products from their process including
lanthanum, lithium compounds, detergents, and alkaloids that have contaminated the local area.
On-site remedial actions were initiated in the 1960s by the Stepan Company which bought
Maywood Chemical Company; however, tests have revealed the lingering presence of lanthanum
chemicals. The site is currently being addressed with Federal and Stepan Company action and EPA
oversight (Figure 4). Because of the interest in potential health effects from the lingering
contamination, a Provisional Peer-Reviewed Toxicity Values assessment for Stable
(Nonradioactive) Soluble Lanthanum (CASRN 7439-91-0) was developed. This PPRTV
assessment identified information sufficient for derivation of subchronic and chronic provisional
reference values that informs risk associated with oral exposures (U.S. EPA. 2018b).
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PPRTVs for Stable (Nonradioactive) Soluble Lutetium and Stable (Nonradioactive) Soluble
Gadolinium
In FY2018, two additional
lanthanide series rare earth metals
were evaluated, lutetium and
gadolinium (Figure 5). The
assessments pertain exclusively to
stable soluble forms of the metals. In
general, lanthanide salts of chloride,
nitrate, and perchlorate are soluble,
while salts of hydroxide, carbonate,
phosphate, and fluoride are
insoluble.
PERIODIC TABLE OF THE ELEMENTS
1
H
He
2
Li
Be
B
C
N
O
F
Ne
3
Na
Mg
Al
Si
P S
a
Ar
<
K
Ca
Sc '
Ti
V
Cr_
Mn
Fe
Co
Ni
Cu
Zn
Ga
Ge
As
Se
Br
Kr
5
Rb
Sr
X :
Zr
Nb
Mo
Tc 1
Ru
Rh
Pd "
Ag
Cd '
In
Sn
Sb
Te
Xe '
6
Cs ;
Ba
¦
Hf
Ta
W
Re
Os
lr
Pt =
Au
Hg *
IL
Pb
Bi
Po
At =
Rn '
7
Fr
Ra
am
Rf
Db
sg
Bh \
Hs
Mt
110 j
Ds •
Rg
Cn
Uut
Uuq
Uup
UuM
Uus i
Uuo =
La i
Ce '¦ Pr 1 Nd i Pm 1 Sm '¦ Eu i Gd '
Jb Dy ' Ho "
Er Tm
Yb
Lu 1
_—
SI,
t s
Th : Pa i U :: Np :: Pu i Am \ Cm
Bk | Es
Fm ? Md
NO ::
Lr i
Lutetium occurs naturally in
the earth's crust and is a soft, ductile,
silvery-white metal that is stable in Figure 5. Rare earth elements include the
air and reacts slowly with water The lanthanides, highlighted in blue
Provisional Peer-Reviewed Toxicity (Photo Credit: pbs.org)
Values assessment for Stable
(Nonradioactive) Soluble Lutetium (CASRN 7439-94-3) updated a PPRTV assessment for "Stable
Lutetium" from 2007 based on recent scientific literature and current PPRTV assessment practices.
The PPRTV assessment identified information sufficient for derivation of a subchronic provisional
reference dose that informs risk associated with oral exposure (U.S. EPA. 2018c).
Gadolinium is a metallic element that is also found in the earth's crust and is a component
of several minerals, including gadolinite and two commercially important minerals, monazite and
bastnasite. Gadolinium exhibits a high degree of magnetism, has superconductive properties, and
is used in neutron shielding, in synthetic garnets to filter microwaves, as a phosphor activator, as
a catalyst, and as a scavenger for oxygen in titanium production. The Provisional Peer-Reviewed
Toxicity Values assessment for Stable (Nonradioactive) Gadolinium (CASRN 7440-54-2) and
Soluble Salts updated a PPRTV assessment from 2007 based on recent scientific literature and
current PPRTV assessment practices. Information available on the toxicity of oral exposure to
soluble gadolinium was limited and uncertainties in the database led to not deriving provisional
subchronic and chronic reference doses. However, to support the needs of the Superfund Program,
a screening subchronic provisional reference dose was derived for soluble gadolinium that may be
of use to risk assessors (U.S. EPA. 2018a).
STSC HOTLINE REQUESTS
A second major function of the STSC is to provide technical support with human health
risk assessments for the Superfund Program through the operation of the STSC Hotline. In
FY2018, the STSC responded to 32 requests from various regions, state agencies, and international
requestors (Figure 6). Of these 32 requests, 10 were site specific, 18 were answerable using
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information from readily available sources (i.e., an Integrated Risk Information System [IRIS]
reference, an active PPRTV, or other existing publication), and seven requests involved additional
research.
In FY2018, 25 of the requests were for chemical-specific toxicity values. When this type
of a request is made, the STSC searches a list of databases (e.g., CompTox Chemicals Dashboard,
IRIS, PPRTV, and other generally accepted sources [HEAST, ATSDR, California EPA]) for
available toxicity values and, if available, the STSC immediately provides the client(s) reference(s)
to these sources. In other cases, the request to the STSC is to address specific technical needs
related to risk assessments of contaminated sites. The following sections highlight a few requests
that deal with chemical or site-specific needs and provide examples of the STSC's work.
Requestor Affiliation [# of Requests]
¦ EPA, OTHER [3]
¦ EPA REGION 1 [3]
¦ EPA REGION 2 [8]
¦ EPA REGION 4 [1]
¦ EPA REGION 5 [2]
¦ EPA REGION 8 [2]
¦ EPA REGION 9 [1]
¦ STATE AGENCY [3]
¦ INTERNATIONAL [ 1 ]
¦ OTHER [8]
Figure 6. FY2018 STSC Hotline Requestor Affiliation
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Evaluation of Suitability of Chemical Surrogates
Traditional risk assessment practices rely on adequate and comprehensive toxicity studies,
primarily in animals, for evaluation of potential human health hazards associated with chemical
exposures. However, many chemicals of interest to Program Office and Regional partners do not
meet the data requirements for conventional characterization of hazard and risk metrics.
Consequently, these data-poor chemicals that do not have associated toxicity values, are not
considered in the calculation of a hazard index, and do not inform cleanup levels. To address this
data gap, a framework was designed to apply an expert-driven read-across approach for
quantitative human health risk assessment (Wang et al.. 2012). The innovative expert-driven read-
across approach relies on the characterization of potential analogue chemicals in the context of
structural, metabolic, and toxicity-like similarity to determine the suitability of proposed
surrogates for the data-poor target chemicals. In FY2018, the STSC provided support using this
approach to evaluate the appropriateness/suitability of analogue chemicals proposed as surrogates
to support clean-up efforts of several data-poor target chemicals identified at Superfund sites.
Examples of these STSC requests are below.
Chemical Surrogate Evaluation for Griffiss Air Force Base Superfund Site - EPA Region 2
In FY2018, the EPA Region 2 requested an evaluation on the suitability of technical
Endosulfan as a chemical surrogate for Endosulfan II for the assessment of noncancer oral toxicity
at the Griffiss Air Force Base Superfund site located in Rome, New York.
Technical Endosulfan is a mixture of approximately 70% Endosulfan I and 30%
Endosulfan II. Structural similarity evaluations conducted by the STSC team revealed
commonalities in basic chemical features and physicochemical properties important for
bioavailability for the Endosulfan-related chemicals. The team also deduced that technical
Endosulfan and its individual components demonstrate toxicokinetic commonalities (including
oxidation to a similar metabolic product that retains toxicity) and displayed similar acute toxicity
potencies in available acute lethality studies. While the acute toxicity data could not be used to
infer on the relative toxicity of Endosulfan-related chemicals in longer-term/chronic exposure, it
increased confidence in the selection of the surrogate chemical and the application of the read-
across approach. Ultimately, the team concluded that based on the weight of evidence, technical
Endosulfan is considered a suitable surrogate for Endosulfan II.
At the same Superfund site, the STSC was asked to evaluate the suitability of technical
chlordane as a chemical surrogate for cis- and /ra//.s-chlordane for the evaluation of oral noncancer
toxicity. Cis- and /ra//.s-chlordane are isomers of chlordane, and major components of the
technical and analytical chlordane mixtures. The team determined that these compounds share
common metabolites; oxychlordane is the major toxic and bioaccumulative metabolite for both
technical and analytical chlordane mixtures and the cis- and trans-isomers. The technical mixture
and individual isomers share similar toxicities and target organs and exert similar acute effects at
similar doses. In addition, other structurally-related chlorinated compounds including major
components in the chlordane mixture show similar target organ toxicities. As such, the team
concluded that technical chlordane was a suitable surrogate for cis- and /ra/7.s-chlordane. This
work was impactful because for this case and the technical Endosulfan case described above,
Region 2 was able to use the information provided by the team with site-specific exposure
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information to calculate a noncancer hazard index for the target chemicals to inform cleanup
decisions, and to be assured that noncancer hazards were not underestimated.
Chemical Surrogate Evaluation for Neper a Chemical Company Superfund Site - EPA Region 2
Region 2 contacted the STSC to evaluate the suitability of either 4-aminopyridine (4-AP)
or pyridine as a chemical surrogate for 2-arninopyridine (2-AP) to aid in cleanup goal development
at the Nepera Chemical Company Superfund site located in Hamptonburgh, New York. Structural
analyses performed by the STSC team revealed clear similarities shared amongst 2-AP, 4-AP
(structural isomer), and pyridine (shared ring structure). An extensive analysis performed by the
team of metabolic processing of these three chemicals revealed no shared metabolites, but that
toxicokinetics are expected to be similar among all three chemicals. Lastly, comparison of toxicity
databases by the team suggested that toxicities of the central nervous system were likely to be
shared amongst all three chemicals. The analysis performed by the team concluded that 4-AP can
be considered an appropriate surrogate for 2-AP, and these efforts facilitated the development of
cleanup values for a data poor chemical (2-AP) of high relevance to public safety at this site.
Chemical Surrogate Evaluation for Naval Weapons Station EARLE Superfund Site - EPA Region
2
Region 2 contacted the STSC to evaluate surrogate suitability for four chemicals (1,3-
dichlorobenzene, acenaphthylene, benzo[#/?/]pyrene, and phenanthrene) found at the Naval
Weapons Station EARLE Superfund site in Monmouth County, New Jersey (Figure 7). This
information was requested to update a human health risk assessment and determine whether the
cancer risks and noncancer hazards at this site were below the protection goal.
Figure 7. Photo of Naval Weapons Station Earle (Site A) in Colts Neck, NJ
(Photo Credit: EPA Superfund Website)
In the case of 1,3-dichlorobenzene, the team determined that 1,4-dichlorobenzene was an
appropriate surrogate for longer duration oral and inhalation exposure. Additionally, a previously
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unconsidered dichlorobenzene isomer (1,2- dichlorobenzene) was determined to be a more
appropriate surrogate for acute exposures to 1,3-dichlorobenzene. For the other three chemicals
of concern, the team developed a weight of evidence justification for each, which was informed
by expert knowledge of the bay-region theory of polycyclic aromatic hydrocarbons to ensure that
the proposed surrogate chemical was health protective in the context of reactive diol epoxide
intermediate formation. Significantly, based on the identification and justification of suitable
surrogate chemicals by the team, the risk assessment was completed, and a decision was rendered
regarding the need for action at the Superfund site.
Understanding Effects of Exposure to Foam Containing Per- and Polyfluoroalkyl
substances (PFAS) in Michigan - EPA Region 5
In FY2018, the STSC and Engineering
Technical Support Center (ETSC) collaborated
on a request from EPA Region 5 to address a
need from the Michigan Department of
Environmental Quality (MDEQ). PFAS foam
was identified on Van Etten Lake and Cedar
Lake in Oscoda, MI near the former Wurtsmith
Air Force Base Superfund Site (Figure 8). The
ETSC provided assistance by compiling
guidance for existing foam and surface water
sampling procedures and analysis methods. The
STSC aided in "understanding the potential
human health implications of per- and
polyfluoroalkyl substances (PFAS) in surface Figure 8. PFAS Foam in Michigan
water and foam by dermal absorption, ingestion, Water, EPA Region 5
and other modes of exposure". (Photo Credit: Michigan Department of
Environmental Quality)
There are several classes of PFAS compounds
and their toxicities vary based on both toxicokinetic and toxicodynamic properties. The potential
human health effects following oral exposure to PFAS compounds have been studied more
extensively than the potential health effects following dermal or inhalation exposures. For
example, comprehensive evaluations of the oral health effects and toxicokinetics of
perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) have been released
previously and can be referred to for further information, and results of previous literature searches
conducted for information relevant to the characterization of human health effects of select PFAS
compounds indicate the majority of available studies examine effects following oral exposure.
With the availability of toxicity information for oral exposure to PFAS, to address the gap
associated with other modes of exposure, the STSC conducted literature searches to identify and
retrieve literature relevant to the toxicokinetics and health effects following dermal or inhalation
exposure to PFAS compounds, including PFOA and PFOS. Few studies have evaluated the health
effects of PFAS following dermal or inhalation exposure; however, the STSC summarized the
evidence for informing human risk of exposure. In summary, the evidence suggested that some
PFAS compounds are absorbed via the dermal and/or inhalation routes, indicating the potential for
human health risk following exposure to contaminated surface water and/or foam (U.S. EPA.
2018e).
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<%fEm? SUMMARY
PRO^
The technical support summarized in this report highlight the variety and impact of
technical support provided by the STSC in FY2018. PPRTV assessments for four chemicals of
interest to the Superfund Program and regional risk assessors were published, providing the
Superfund Program with eight unique toxicity values. These newly derived toxicity values will be
used to inform site screening and cleanup levels at Superfund sites across the United States.
In addition, the STSC responded to 32 requests to provide technical support to the
Superfund Program in the area of human health risk assessments from various regions, state
agencies, and international requestors through the operation of the STSC Hotline. The STSC serves
a unique role to the Superfund Program community as a bridge between the site-specific regional
risk assessors and the ORD risk assessors. Through the STSC Hotline, ORD scientists addressed
the critical and time-sensitive needs of the regional scientists by activities such as providing
toxicity values for chemicals of interest and evaluating suitability of chemical surrogates. As such,
the STSC acted as a key part of the larger TSC Program in ORD that is dedicated to serving the
EPA and its clients ultimately resulting in lasting differences in communities across the country
and ensuring public health protection.
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PRO*^0
CONTACT INFORMATION
Teresa Shannon
STSC Administrator, NCEA
(513) 569-7596; Shannon.Teresa@epa.gov
Beth Owens
STSC Director, NCEA
(513) 569-7241; Owens.Beth@epa.gov
U.S. Environmental Protection Agency
26 W. Martin Luther King Drive
Cincinnati, OH 45268
STSC Hotline
U.S. Environmental Protection Agency
26 W. Martin Luther King Drive
Cincinnati, OH 45268
(513) 569-7600; Superfund STSC@epa.gov
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REFERENCES
U.S. EPA (U.S. Environmental Protection Agency). (1988). Integrated risk information system
(IRIS) Chemical Assessment Summary for toxaphene. Washington, DC: Office of
Research and Development, National Center for Environmental Assessment.
https://cfpub.epa.gov/ncea/iris/iris documents/documents/subst/0346 summary.pdf
U.S. EPA (U.S. Environmental Protection Agency). (2005). Guidelines for carcinogen risk
assessment [EPA Report] (pp. 1-166). (EPA/630/P-03/001F). Washington, DC: U.S.
Environmental Protection Agency, Risk Assessment Forum.
https://www.epa.gov/sites/production/files/2013-
09/documents/cancer guidelines final 3-25-05.pdf
U.S. EPA (U.S. Environmental Protection Agency). (2018a). Provisional Peer-Reviewed
Toxicity Values for Gadolinium [EPA Report], (EPA/690/R 18/001). Washington, DC.
U.S. EPA (U.S. Environmental Protection Agency). (2018b). Provisional Peer-Reviewed
Toxicity Values for Lanthanum [EPA Report], (EPA/690/R-18/004). Washington, DC.
http s: //cfpub. epa. gov/ncea/ pprtv/recordi spl ay. cfm ?deid=342811
U.S. EPA (U.S. Environmental Protection Agency). (2018c). Provisional Peer-Reviewed
Toxicity Values for Lutetium [EPA Report], (EPA/690/R-18/003). Washington, DC.
https://cfpub. epa.gov/ncea/pprtv/recordisplav. cfm?deid=342950
U.S. EPA (U.S. Environmental Protection Agency). (2018d). Provisional Peer-Reviewed
Toxicity Values for Toxaphene [EPA Report], (EPA/690/R-18/002). Washington, DC.
http s: //cfpub .epa. gov/ncea/ pprtv/recordi spl ay. cfm ?deid=342137
U.S. EPA (U.S. Environmental Protection Agency). (2018e). Response to Request from
Michigan DEQ for Effects of Exposure to Foam Containing PFAS [EPA Report],
Cincinnati, OH: U.S. Environmental Protection Agency, National Center for
Environmental Assessment.
Wang. NC: Zhao. OJ: Wesselkamper. SC: Lambert. JC: Petersen. D; Hess-Wilson. JK. (2012).
Application of computational toxicological approaches in human health risk assessment.
I. A tiered surrogate approach. Regul Toxicol Pharmacol 63: 10-19.
http://dx.doi.Org/10.1016/i.vrtph.2012.02.006
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