DEQ-CFW_00022191

From: Culpepper, Linda [/o=ExchangeLabs/ou=Exchange Administrative Group
(FYDIBOHF23SPDLT)/cn=Recipients/cn=73d475cbae324a29687e1711dc9a79c5-ImcuI pepper]
Sent: 7/9/2017 2:05:06 AM
To: Holman, Sheila [/o=ExchangeLabs/ou=Exchange Administrative Group
(FYDIBOHF23SPDLT)/cn=Recipients/cn=94a3f69674d34b769b3bd834a97105c5-scholman]
Subject: Fwd: GenX Risk Assessment Knowledge Gaps
Sent from my iPhone
Begin forwarded message:
From: °Behl, Betsy" <Behl.Betsy @e a.gov>
Date: July 7, 2017 at 6:34:24 PM EDT
To: "Risen, Amy J°' <r� .iiserd1Is.nc, ov>, Audra Henry <ataJ. 4cdy>, "Wheeler, John"
<Wheeler,John@e aa.aov>, "Mitchell, Ken" <Mitchell.Ken (b)ea, o,,>, "Strong, Jamie"
<St€or x. arni f :p .::.xpy>, "Henry, Tala°' < enEy: lg.Ccz ,.p ::.xpy>, "Behrsing, Tracy"
<het3€sin .:rac , a a, ov>, "Benson, Amy" <Benson,Arn , &De :€a. ov>, °'Aubee, Catherine"
< ubee.Catherine(@e a. ov>, "Kemker, Carol" <Ke€nker,Carol(@e�a.�ov>, "Allenbach, Becky"
< Ilenba ci .Bc
...........-� ais c,.p :py>, "Mort, Sandra L°
................................"'.
<sa€�d .rnori:@ncdenr.gov>, '°Shehee, Mina" <r it ; ,sl at3€ e dl l .n :. €:�v>, "Elizabeth Dittman"
<Beth.Dittmam' dhhs.nc.Pov>, "Holt, Kennedy" <Ke€ nedy.i colt dhhs.nc. ov>, "Langley, Rick"
<€ I D#'�����froye€..: > Culpepper, �� . . .
Linda" <hnda.cul e er` € cde€ €. €€v>, "Holloway, Tracey S'° < race .H€:�lloov>,
"Donohue, Joyce"
Cc: "Tina Forrester" <t:xf @c c:.B.p�:>, Susan Moore <syr��� � c:g��y>, Selene Chou
............... ....
Trent LeCoultre <t1l7@cdc.P-ov>1 °idz71@cdc.�,ov° <idz @cdc. ov>
Subject: RE: GenX Risk Assessment Knowledge Gaps
From: Risen, Amy [Mailto:r€ .Rise€��ds.€�c. o]
Sent: Friday, July 07, 2017 6:17 PM
To: Audra Henry « i. cdc g v>; Wheeler, John < heele.r,Joh n-re,)- - ov>; Mitchell, Ken
< itchell,Ken epa.gov>; Behl, Betsy < ghLBets- ea.„ov>; Strong, Jamie
Henry, Tala <tD..1...'p:.€x.>; Behrsing, Tracy <c3trs€iJ.x.trc.c.p.zy>; Benson, Amy
<Benson. ,rv)�,r,c�e )a. � ov>; Aubee, Catherine <Aube.e.CF: Cheri€ e. @e F --,?>; Kemker, Carol
<I errker.Ca€ol � epa, ov>; Allenbach, Becky <A1lenbach,Beckvz@epa.„ov>; Doa, Maria
<Doa,Maria�Sc���:���y>; Mort, Sandra L<=,F:�€�€�y. � �.�.��r�c ����.. ��y>; Shehee, Mina
.................................... ..
<rnina.shehee@dhhs,nc.gov>; Elizabeth Dittman <Beth,Dittmam' dhils.rc. ov>; Holt, Kennedy
<Kenned .Holt@,dhhs.nc.�?ov>; Langley, Rick connie.brower@ ncdenr,gov;
Culpepper, Linda Holloway, Tracey S <T€ace.y >;
.......................... Donohue, Joyce <Ionodue,u cee a, ov>
Cc: Tina Forrester <txf.5r,1cdc,gov>; Susan Moore <*; B zsc.dca ; >; Selene Chou <c c3(q-)cdc.-ov>; Trent
LeCoultre <t' 1'7" c ',g �y>; € z c, c:.g y
Subject: RE: GenX Risk Assessment Knowledge Gaps
Thank you to everyone for providing feedback on our risk assessment for GenX. I'm providing a
summary below, which includes points of contact to follow up with. Questions 1-4 were posed by DHHS
before the call as main talking points. Text in blue is a summary of the comments. NC DHHS makes every
attempt to follow the approach used by the EPA when doing risk assessments. Therefore, we have
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underlined blue text as take home messages that DHHS will be applying to the GenX risk assessment for
NC residents using drinking water originally referenced in Sun et al 2016.
DHHS intends to respond to the public with a new drinking water level and health guidance early in the
week of July 10th. We are hopeful that you will be able to provide feedback on cancer and fish
consumption ASAP; please see number 5 below for details. I am also interested in data we discussed on
interspecies kinetics differences.
Thanks again!
Amy
1) <!--[if !supportLists]--><!--[endif] -->Animal toxicity studies and the point of departure (POD):
Sufficient data was available to lower the POD NOAEL to 0.1 mg/kg/day (subchronic toxicity test
OECD 407 with mice). An uncertainty factor of 10 will be applied for subchronic to chronic
extrapolation
a. <!--[if !supportLists]--><!--[endif]-->We have consensus that the POD of 0.1 m k da
0.1 als. b.e..0 e .. 3.the_-EPA isle- Kess e0 - y si.p ..� �..fs�� disk_.assessment -o
GenX,
b. <!--[if !supportLists]--><!--[endif] -->Joyce Donohue, Tracy Pehrsi€ g & Amy Benson
requested that toxicological effects and e€ dpcoint: descriptions be strengthened so we.,.
can he more specific about the effects associated with N0AELs and PODS that are
referenced during the risk assessment.
c. <!--[if !supportLists]--><!--[endif]-->It was noted that PODS on the ECHA riossier are
selected and reported by chemical manufacturer rather than the ECHA.
2) <!--[if !supportLists]--><!--[endif] -->Routes of exposure and the relative source contribution
(RSC): People may be exposed to GenX through routes other than drinking water. The typical
value used for RSC in risk assessment of organic chemicals is 0.2, and this is the value used by
the EPA for their evaluation of PFOA and PFOS drinking water health advisories. We re Vest
g.g.i.d.a.fl.c.e.fr2m thee F.A enact A.T.S.D.R. oal-the. € se of afl R.S.0 of.Q., ...
a. <!--[if !supportLists]--><!--[endif]-->EPA RAD has not evaluated RSC for drinking water
exposures to GenX because drinking g water was not previously thought to be a route of
exposure to this the€nicaL
b. <!--[if !supportLists]--><!--[endif]-->EPA OST gq�Q did use 20 RSC for PFOA -arid PFOS
clue to ubiquitous presence in the e€ viro€ rnent: and of these
chemicals reaching People through the different exposure routes.
c. <!--[if !supportLists]--><!--[endif]-->EPA OST RAID -uses 100% RSC when looking at
exposures to the infant age group.
d. <!--[if !supportLists]--><!--[endif]-->DHHS intends to use 0% RSC based on the EPA
decision tree for derivira water u lix criteria EPA-822-B-0:1 )4):11 and apply the
e osre to children iirtE t€ <6 ears€si ex os€re factors from the new EPA RAGS
..fie -20
r-
3) <!--[if !supportLists]--><!--[endif] -->Risk assessment method and interspecies uncertainty
factor: The default value for interspecies variability of 10 is likely to underestimate the toxicity
of GenX to humans. We present the EPA method used to extrapolate a human equivalent dose
(HED) for PFOA and PFOS in this document. Interspecies uncertainty modeling for PFOA and
PFOS yielded a calculated factor of 140 to 710X for kinetics differences and an additional 3X was
allocated for other variability across species. The total uncertainty accounted for across species
by EPA for PFOA and PFOS was calculated by DHHS and the maximum was 2,100X. We also
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�q gst. idance_fror the. EPA and a�T ..o ._��_�.ppr�a��iat�..inters ties uncertair�tyjp.�tgr
......................
for GenX.
a. <!--[if !supportLists]--><!--[endif]-->DHHS understands that EPA RAD currently intends
to use a UFE-,,,�=100 for their risk assessment for the consent order for GenX
---------- &&
ranfacturing 4EEn r_;ase_ric=.s0 arc E,Fc'rs�G s o
b. <!--[if !supportLists]--><!--[endif]-->EPA: While human PE g & PEOA clearance rites are
slower in humans than test ani€rals, interspecies kinetics variability is net expected to
occur at the sa€re magnitude for GenX. The supporting information cor es fr€ rn a
comparison of the clearance rates for branched vs linear PFOAs, in which branched
isomers are cleared faster, GenX is branched and so would he predicted to clear faster.
i. <!--[if !supportLists]--><!--[endifj-->DHHS requests references on comparison of
branched vs linear PFOAs, renal transfer proteins used, and any additional
information helpful in reviewing the prediction of the interspecies variability
exppect:ed for GenX. Eolk�w up disc€�ssions will go through .loyce Donohoe,.
Catherine Aubree, and Jaime Strong as points of contact.
c. <!--[if !supportLists]--><!--[endif] -->AdditionaI DPs were discussed, including the
sobchronic to chronic extrapolation. EPA PAD does not use a UFsundm,,,s€,: as part of
its typical procedure. DHHS explained our goal to he protective of public health over a
lifebrne of exi., osure. EPA explained that EPA IRIS rocedure does focus more on
lifetime ex osures and their risk assessment does add in e Dk,£o-,:�r,:r-r3rur3E< of 10.
d. <!--[if !supportLists]--><!--[endif] -->Quest:ions were. raised regarding EPA's current
review of the GenX consent order and associated risk assessment: now that a release to
a water source is known, will the risk assessment include a public drinking Lasater level:'
4) <!--[if !supportLists]--><!--[endif] -->Drinking water concentration guidance for other PFECAs:
The Sun et al 2016 publication identified not only GenX, but also other perfluoroalkyl ether
carboxylic acids (PFECAs) present in the Cape Fear River and local drinking water in 2013 and
2014. Quantification of the concentrations of other PFECAs was not possible due to the lack of
analytical chemistry standards, however some PFECAs may have been present at concentrations
15 times higher than GenX. Presumed high concentrations are prompting questions about
drinking water safety, however no toxicity data is available for these PFECAs. We rest
€aidance frorn the EPA and ATDR on a health rotective drir kin water value that can be
plovi e to residents of this co ur�it�a Would..).:._ e_a.i1i1���! [�t� tp gs.e E .q._REO± T.F
health advisor of 70 n L?
a. <!--[if !supportLists]--><!--[endif]-->N"aria Don and Catherine Aubree will € e'vie' the
PFECAs chemical structures tc) see if general advice can be given on bow rnuch we can
read across health concerns from PFOA and PFOS, It is not within the scope of their
work on GenX to review PFECAs at this time and it is understood that guidance along
these lines may be limited. Amy Risen will provide the sapplernental docornent for Sun
et al to clarify the PFECAs in question.
5) <!--[if !supportLists]--><!--[endif] -->AdditionaI questions raised in call
a. <!--[if !supportLists]--><!--[endif]-->Fish Consumption:
i. <!--[if !supportLists]--><!--[endif]-->Dl- HS� The Public is askingabout safety of
fish consumption, Can the EPA €rake any recommendations?
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<!--[if !supportLists]--><!--[endif]-->EPA: The EPA does riot expect GenX to
bioaccurnulate,There is some data on concentrations in fish from docurnents
that are confidential, as well as some non -confidential data,
1. <!--[if !supportLists]--><!--[endif]-->Tiie DHHS smoke with Tala Henry
after the call for clarification. She explained that the BCC reported by
Hoke et al 2016 is low enough as to not typically warrant -additional fish
consum ptioms studies, EPA. will follow € p Monday with a statement with
the appropriate caveats for the unknowns of emerging chemicals and
limited data.
b. <!--[if !supportLists]--><!--[endif] -->Cancer Risk Assessment:
<!--[if !supportLists]--><!--[endif]-->D S; The public is concerned about the risk
of cancer fr€:ern GenX. We. have limited data, but can the EPA suggest a way to
convey the risk of cancer:'
<!--[if !supportLists]--><!--[endif]-->EPA; Joyce Donohue will review the raw data
from OECD 453 to determine if the rotes on the rate of occurrence for liver
necrosis are sufficient to calculate a risk. Amy Risen will provide ffie: raw data,
which had been provided by Chernours, Arny also has raw data for OECD 407
GenX testing for rats & €nice, if needed by anyone in the group.
From: Risen, Amy J
Sent: Wednesday, July 05, 2017 7:38 PM
To: 'Audra Henry' <at 1��zsc a y,>; 'John Wheeler' < I I E.J ..1 :#a :>; ° itc Il. r
<€nit:cl�ell.ken S u. €:�v>; 'P€
'Peh€sin .tracyQ-op .gov'
<B .hrs€€rg.tr���c:��� �.i��.. ��y>;' �r1� r1:I y-�� .P.�.,gp�' < 'nso .FjnnY� fp�:g���:>;
..............
'Aubee.cathe€ €ne@e a, qV <ALrbee.cather€ne@:e a,�ov>; 'Ker iker.carol@e a.PoV
<Kemker,carol(e a. ov>; 'Allenbac.h.beck. @e a.Rov° <All€ nbach.beckyrla)epa.gov>; 'Doa, Maria'
< oFj,Maria�S����.���y>; Mort, Sandra L<=,F:�€�€�y. 1 �.�-��rlc ����.. ��y>; Shehee, Mina
.................................... ..
<€nira.shobee@dhhs,nc.gov>; Dittman, Elizabeth <Beth,0ittmanz dhhs.rc. ov>; Holt, Kennedy
<Kennedy.Holt@,dhhs.nc.t?ov>; Langley, Rick Brower, Connie
..€..€:?`...
.............................................
Cc: 'Tina Forrester' <txfS�ov>; 'Susan Moore' <2 € q cdc. ov>; 'Selene Chou' <c c o ,+>;
'Trent LeCoultre' <tl @q)cdcdc.gov>; 'Rachel Worley' <€d f cdc.&ov>
Subject: GenX Risk Assessment Knowledge Gaps
•
NC DHHS has been discussing GenX with both EPA and ATSDR and we really appreciate the help you've
been giving us. We'll be holding a conference call tomorrow to talk about the progress we've made on
our GenX risk assessment, and talk about knowledge gaps. We'll be asking for rapid feedback within the
next week to help inform our risk communications with the public.
I've attached a document for you to review with requests for feedback bolded in purple.
Thanks so much and talk to you all tomorrow!
Amy Risen, PhD
Environmental Toxicologist
Division Public Health, Occupational and Environmental Epidemiology
North Carolina Department of Health and Human Services
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