Document XRVE5jn9rE4byq1VYMMqdxxB

Attention: Docket Number EPA-HQ-OW-2014-0138 April 28,2014 We appreciate the opportunity to comment on the draft "Health Effects Document for Perfluorooctane Sulfonate (PFOS)". Our comments relat to the critical effect chosen by the United States Environmental Protection Agency (USEPA) as abasis for derivation of the Reference Dose (RD). As authorsof the developmental neurotoxicity studyofpotassium PFOS in rats from which USEPA chosethercritical effec for derivationofthe proposed RD (ButenhofeTt al. 2009), we. are disturbed by the choiceofa single, transient observation in one sex from that study without full considerationofthe lack ofevidence for developmental neurological effects observed in the sbtausdeyd aosn wceolnlsaescuctoirvreobtoirmaet-ipnegrisotdudileosc.omoUtSorE-PacAticvhiotsyemtehaesoubrseemrevnattisomnoadfreeodnucpeodstnhaatbailtudaatyi.on o(bPsNeDr)vat1i7onian s1.a0crmigt/ikcgal/denmdaptoeirnntaltoddoesreivgeroaupRImDalfeorpurpesg.ulaTthoreyupsueorpfotsheisswshinegnle,mtorranssiiegnntificant ddaetmaonasrtraavtaeilnaobrlmeaflronmeutrhoeloBguictaelndheovfeeltFoaplm. esnttudiys, aatsowdedlsl waistohtghueirdsatnucdeiesfomr ednattiaoinnetderbpreeltoawt,iotnhaitn d(eOvEelCoDpm2e0n0t7a)l, anneudroUtSoExiPcAi'tyssotuwdniegsuoiudtelliinneeds (inUFSrEanPcAis1e9t9a1l,. (11999980)).,TOhEeCseDTgueisdteliMneetshsotadte42th6at a weightofevidence approach and expertjudgment should be used. It i evident that his has not been the case in derivationofthe proposed RID for PFOS. tLhoecostmuodtyorusaicntgivsiettysowfa2s0onpeuopfs mpearnsyexdepveerlmoaptmeernntaalldnoesuerogtrooxuipc,olaongdictahliseennddppooiinntts wevaasluaastseesdsiend on PND days 13, 17, 21, and 61. The characteristic inverted "U" pattern in cumulative locomotor activity over a 60-minute period was observed in all PND 21, with higher activity on PND 17 than on PNDs 13 and 2g1r,ouwpassboebtsweerevnedPiNnDall13graonudps (`gFrioguuprseh2adinsBtauttsteinahlloyfe-tTsiganli.fivicdaentilnyfrha)i.gheMracluemupluaptsivine tlhoec0o.m3otaonrd a1c.t0ivmigt/ykags/cdommaptaerrendaltodose controls on PND 17. aHcatbiivtiutaytiaosns,ayaapsriwmeiltliavse ffroormmodfatlaeaorbntianign,edwaisn tehvealaucaotuesdtifcrsotmardtlaetaasosbaty.ainWedheinntPheNlDoc1o7motor lmoactoemmoatlordoascteivgirtoyucpomuantlsewpeurpes edviadlnuoattesdhionwsetqhueennotiramlal13d-immiinnuutteiotnimien mpeortioordsa,cttihveit1y.0ovmegr/tkhge/d 60-minute period (habituation) that typically canbeobserved on PND 17 (Figure 3 in Butenhofl etal, vide infra). However, the motor activity pattemofthese males, including habituation, was not different than that of the control males on PND 21 and 61, nor was it different on PND 13. Therefore, the observed PND 17 reduced habituation response in 1.0 mg/kg/d dose group males rleilkaetliyvreetporecsoennttrsolamlailgehtpdupesv;eltohpermeefnotrae,l pdeulpayb.odTyhewseeigmhatlaelponuepdbooedsynwoetiegxhptlsaiwnertheenaoptpaafrfeenctted delay. However, body weights of the 1.0 mg/kg/d dose-group dams, tracked lower than controls, mbuetawnitbhooduytwsetaitgihsttiscoalfstihgensiefidcaanmcse,wtahsroluogwheoruwtimtohssttoatfistthicealgessitgantiifoincapnecreiofd,roamndP,NaDs4a rtehsruoltugh PND 21 (weaning) (Figure 1of Butenhofeft a., vide infra). Thus, the matemal influcnce on a slight delay in habituation cannot be ruled out. Gene transcriptional profiling of iver tissue obtained from dams and fetuses on gestation day (GD) 20, and from male pups at weaning on PND 21 indicated increased CYP2B2 expression in GD 20 dams and increased Acox, Cyp2B2 1 Attention: Docket Number EPA-HQ-OW-2014-0138 April 28,2014 afonrdaCdyappt7iAvle meextparbeoslsiiconreisnpPonNsDes2t1o wmahliechpurpodse(ntCshaanregketnoalw.n20t0o9b).e paTrhteiscueladraltyaspernosviitdiveeerveildaetnicvee. to humans (Cheema and Agellon 2000; Corton etal. 2014; Elcombeetal. 2014). The potential contributionofthese metabolic adaptations to the observed locomotor habituation response on PloNcDom1o7taolrsaoctdievisteyrvaensdfhuarbtihteuractoinosnidreersaptoionns.es Roefg1a.r0dlmegs/skogf/dcaduossee,-gthreoufpacmtarleemapiunpsstwheatrethneot statistically significantly different than male controls on PNDs 13, 21, and 61. As noted above, acoustic startle response habituation was also evaluated in the same sets ofmale: pups on PND 20 and 60. Habituation to acoustic startle response was unaffected by maternal treatment with potassium PFOS on either PND (Figures 4 and $ for males and females, respectively, of ButenhofeTt al, vide infra). Thus, this measureofhabituation also showed normal attainment. In addition to habituation as a measureofprimitive learning, higher learning and memory were evaluated in three phasesof the Biel maze swimming assessment on PND 22 through 28. In these phases, rats were placed in a water-filled maze and required to swim through the maze to `fminedasaurseudbmsewrigmemdipnlgatafbiolrimtyfarnodm wmohtiicvhattihoeny tcoouelsdcaepsec.apRea.tsPhwaesree 1p,laccoendduicnatedstoranigPhtNcDha2n2n,el opposite the submerged platform, and time to reach the platform was recorded in four consecutive trials. There were nostatistically significantdifferences between groups in time to reach the escape platform during the four trials, withal rats showing similar decreases in time. during the four trials (Figures 6 and 7 for males and females, respectively, of ButenhofT et al., vide infra). Phase 2 evaluated sequential learning over PNDs 23 through 27. On PND 23 and 24, rats were allowed two tials to solve path Aofthe maze. This was followed on PNDs 25 tRhartosuwgehr2e7wgiivtehn t1w8o0 tsreicalosnpdesrtdoasyol1v0estohlevepaptahthBBmaofzteh.eImfaitzew,aswhniocthsowlavsedt,hethreeyvewresreoefpplaactehdAo.n the escape platform for 20 seconds and then removed from the maze. The two daily trials were. separated by a minimum ofone hour. As shown in Figures 6 and 7 of Butenhofeft al., there was no effectof maternal treatment on sequential learning. Memory was tested in phase 3, conducted on PND 28. The rats were allowed two tials 0 solve path Aofthe maze. Again, no effect of wmrait-eprhnaasilctBrieealtmmeanztewistwhiPmFmiOnSgwtarisalotbessetrpvaerda(dFiiggmurteose6vaalnudat7e olfeaBruntiengnhaonfdfemteamlo.ryTdhiedrenfootre, the reveal an effectof PFOS on the studied parameters. "The lackofan effect on learning and memory is supported by the resultsof Lau etal. (2003) and Luebkerct al. (2005). In Lau et al, PND 22 rat pups from dams given 3.0 mg/kg/d throughout gestation did not diffe from controls when tested using a T-maze with alienation (Figure 4 of Lau etal, vide infra). In Lucbker etal, F1-generation pups were tested for learning. short-term retention, and memory in a passive avoidance paradigm beginning on PND 24, and, beginning on approximately PND 70, were evaluated in a water-filled M-maze for neuromuscular coordination, swimming ability, leaming, and memory. No effectsoftreatment were observed. Inthe developmental neurotosicology study reported by Butenhoff etal, there were no other observations among the many recorded that were suggestive ofaneurotoxicological effect of PFOS on development through the PND 66 observation period.A functional observation battery 2 Attention: Docket NAupmrible2r8,E2P0A1-4HQ-OW-2014-0138 (FOB) and 60 was and performed with the same sets of20 ratspersex per included, stageof development permitting: caseof group on PNDs 4, cage removal; ease 11,21, 35, 45, of handling in chlaonsdu;rel;arcersipmiartaitoonr/ycrhartoem/ocdhaarcarcytoerrt;hreead;, scarluisvtaytidoenp;ospiitlso;crmeuctciooun;sampepmebarraannecse/osfkifunr;coplaolrp;eberyael prominence; eye color; mobility; muscle tone; convulsions/tremors; hindlimb extension; `grooming; arousal; bizarre/stercotypic behavior; urination/defecation; papillary response; backing; forclimbhindlimb grip strength; tail pinch response; gait; andair righting. Noneof these FOB endpoints was affected by treatment with PFOS. no no a ano lepers by PND 21 an tres of Based on the weightofevidence, it is unreasonable for USEPA to choose the PND 17 that normal response when evaluated on PND 61, along with the lack of& PFOS-ireatment effect 2`eonndapcooiunsttsicevsatlarutalteedreisnpotnhesesthuadbyi.tuaItnitohne,irarsepweolrltoasfatlhleoUf SthEePmAanWyoorthkesr hkoeynpnethueroQduealvietlaotpimveenatnadl Quantitative Comparabilityof Human and Animal Developmental Neurotoxicity, Francis ct al. Work Group [11 (15) also addressed interpretationofdevelopmental neurotoxicity end ts monkpe in be oni. `consideredan adverse effect in certain cases, but that a statistically significant effectfor dn rr robo os ren ect epee neurotoxicity. The data must be evaluatiend the contextofother information (e.g., dose: response, correlation with otherfindings, degreeofconsistency in termsofother known effectsof the agent) in order to provide a measure ofthe confidence in the data and in the es pt fe bom door rotons dsesnd at the Workshopproduce a varietyofbehavioral, newropathologic and other types of gr Hhetratecwehsacdongsevimspofmsirosns and measures that generally would be expected 10 be highly intercorrelated. In the end, es pscliaeyntaifriocljeuidngeimnetnertp,rewthiincghthmeutsotxitcaokleoignitcoalacsciognuinfticalalnctehoefdsatattaisatviaciallalbylesiognnifaincaangtent, will ied ser, We peat ease hk SEA oor ches The weightof evidence suggests that PFOS shouldnotbe viewed as a specific developmental neurotoxin, and USEPA's choiceofcritical effect for the RID is at odds with the guidance of critical endpoint, Rept smite, Gln 2. Bobet ff J e ar-- iit Sed -- urit.o ty AST Sin, US. -- ; P-- apers: iReh Attention: Docket Number EPA-HQ-OW-2014-0138 April 28,2014 ButenhofetT al. (2009) Figure | TT --] i/ = iA `Butenhoeftf al. -- (2009) Figur2e | | | "ul adil | | || A . Attention: Docket Number EPA-HQ-OW-2014-0135 April 28,2014 ButenhofeYt al. (2009) Figure 3 ESR "- || || | ia- ||i 1|f i. | . | ee cy 7 pent ee y(0)20dSous TiPm cir ) ne Butenhofeft al. (2009) Figure 4 P[ cvmmaammesaonms nasrtaes { = FT i Bl lL | iEo |im fetdtre | || | II =i i Ii || HARA SpA PATS SRA s Attention: Docket NAupmrible2r8,E2P0A1-4HQ-OW-2014-0138 Butenhofeft al. (2009) Figure 5 Comores B01msNaa MOOS WiOTONGS | IE | pil | - ii i | : il | | na Butenhoff etal. 2009) Figur6e TT wees meres umes Tweens | im toll i I | | wl | | 1] 1 [I1l | i| Hd | Sh I ! 1 | | | 6 tenons Dot NspeEPRHROWIIAALTS A, ufNET MI - i= i(EIfRh grB01mores 1 | TT meamerga i al hil | 1 | wiomongd . i hoo LR || 1 ort, (oan a -------- Lau etal. (2003) Figur4e ERE H HJ bf dhn p [Fo HA on aSie ee a Co wya PesWRAP 8aie , Attention: Docket Number EPA-HQ-OW-2014-0138 April 28,2014 Citations in the text Butenholafcft,atiJ.oL.n,aElherxepsomsaunr,eDt.Jo.,pCothaasnsgiu,mSp.Ce.rfPlaurokreocrt,anGe.sAu.l,foSntautmep(,KDP.GF.O,S2)009in. rGae:stational and Chang,d$e.vC.e.loEprmeesnmtaaln,neDu.rJo.t,oxBijcoitryk.,RJeAp,roWadlTloaxcei,coKl.,27P,ar3k1e9r-,3G3.0A.., Stump, D.G., Butenhoff, JL. 2009 Gestational and lactational exposure to potassium perfluorooctanesulfonate (K+PFOS) in rats: toxicokinetics, thyroid hormone status, and related gene expression. Cheema,ReSpKr.od ATgoexlilcoonl,2L7,B3,872-030909..The murine and human cholesterol Zalpha-hydroxylase gene promoters are differentially responsive to regulation by fatty acids mediated via Corton,p.eCr.o,xCisuonmneinpgrohlaimf,eraMt.oLr.-,acHtiuvmamteedrre,ceBpTt.orLaalup,haC.., MJ eBicokl,ChBe.mPe2t75e,rs1,J25M3.0,-P1o2p53p6..L.A., Rhomberg, L., Seed, J. Klaunig. J.E., 2014. Modeofaction framework analysis for receptor-mediated toxicity: The peroxisome proliferator-activated receptor alpha (PPARalpha) as a case study. Crit Rev Toxicol 44, 1-49 Elcombe, C.R., Pefler, R.C., Wolf, D.C., Bailey, J. Bars, R., Bell, D, Catley, R.C., Ferguson, SScSh.oeGneyt,erR,.,D.X,ieG,oeWt.z,,LAa.k,eG,oBo.dGm..an2,01J4.1., HMeosdteero,faSc.,tiJoancoabns,d hA.,uOmmainecrielnesvkain,ceC.aJ.nalysis for nuclear receptor-mediated liver toxicity: A case study with phenobarbital as a model constitutive androstane receptor (CAR) activator. Crit Rev Toxicol 44, 64-82. Francis, EZ. Kimmel, C.A., Rees, D.C., 1990. Workshop on the qualitative and quantitative `comparabilityofhuman and animal developmental neurotoxicity: summary and Lau, C,iTmphliibcoadteioanusx.,NLeRu.r.otHoaxniscoonl,TeRr.aGt.o,lRo12g,er2s8,5-J2M.9,2.Grey, B.E., Stanton, M.E., ButenhofT, JL. Stevenson, L.A., 2003. Exposure to perfluorooctane sulfonate during pregnancy in rat and mouse. II postnatal evaluation. Toxicol Sei 74, 382-392. Lucbker, D.J., Case, M.T., York, R.G., Moore, J.A., Hansen, K..., Butenhoft, J.L., 2005. Two`generation reproduction and cross-fosterstudiesofperfluorooctanesulfonate (PFOS) in rats. Toxicology 215, 126-148. OECD,D2e0v07e.loOpmEeCntDalGUNeIuDrEotLoIxiNcEitFyOSRtudTyH,EadToEptSeTdIONcGtoObeFrC1H6,E2M0I07C.ALS: Guideline 426, USEPA, 1991. Guidelines for developmental toxicity risk assessment. Federal Register 56, USEPA,631799988-.63G8u2i6d.elines for neurotoxicity risk assessment. Federal Register 63, 26926-26954. 8