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US EPA OR J Toxicity of PFA I ' w rrrr ' ' - ^ / / L Mi Uliixlil US EPA Office of Rt National Center fo Sierra Club v. EPA 18cv3472 NDCA Tier 10 *' ' : * -*S +< It * .' ' .* `T*. * . ' ' * < ^ t * X *& &. -i*;%:m ** * * x ** * . & ' ED 002061 00269050-00001  Problem formulation: - Hundreds to thousands of untested PFAS in the environmem - Traditional single-chemical toxicity testing not practical or efficient - Toxicity and toxicokinetic information needed to inform decision making How do we generate informative toxicity and kinetic information quickly? - EPA ORD, National Toxicology Program (NTP) and partners have the capacity to generate toxicity and toxicokinetic data through high throughput methods (HTT) assays Sierra Club v. EPA 18cv3472 NDCA Tier 10 ED 002061 00269050-00002  Procure a library of "300-400 PFAS (PFAS Screening Library) to support development of analytical methods, environmental monitoring, and toxicity testing Define a reference subset of "75 PFAS based on: -- Conduct tiered toxicity and toxicokinetic testing chemicals within the PFAS landscape - Data will support multiple outputs, making use of the integrated dataset (in vivo, in vitro, etc.) to inform toxicity and kinetics across the PFAS landscape Not for Release Sierra Club v. EPA 18cv3472 NDCA Tier 10 ED 002061 00269050-00003 EPA DSSTox Database: > 758K chemicals Span nin g public II <v interest to ERA -? 'tocmpt to procure hmmeals w/ structures) i 'FAS Screening Library (procurements in-process) S of interest to ERA osure, occurrence, tox data) -2* '' Reference subset {tiered toxicity & toxicokinetic testing) Sierra Club v. EPA 18cv3472 NDCA Tier 10 EPA 'Rfluorinated alkyl substances (PFAS) ;mical names, acronyms, synonyms mical structure categories ED 002061 00269050-00004 Tier 1 In Vitro Toxicity and Toxicokinetic Assays -7 5 Reference PFAS Human Exposure Characterization High Potential Risk Tier 2 In Vivo Toxicological and Toxicokinetic Assays *Collaboration between EPA and NTP Sierra Club v. EPA 18cv3472 NDCA Tier 10 ED 002061 00269050-00005  PFAS potency estimations: Primary outputs will be administered dose equivalents (ADE) and Bioactivity-toexposure ratio (BER) -- Characterization of uncertainty is critical to decision context Communicate characteristics for Tier I data to partners and stakeholders in advance for use-considerations in different decision making contexts Prioritize PFAS for Tier 2 in vivo testing Mot for Release Sierra Club v. EPA 18cv3472 NDCA Tier 10 S ED 002061 00269050-00006 ORD Medium Throughput Research Studies Mot for Release Club v. EPA 18cv3472 NDCA Tier 10 h ED 002061_00269050-00007  Established model of vertebrate embryonic d e ve lo p m e n t Rapid, external d e ve lo p m e n t ~75% o f genes have human homologs Transparent Transgenics, mutants Amenable to chemical screening Not for Release Sierra Club v. EPA 18cv3472 NDCA S ________ 0-24 hpf; Karlstrom etal. Dev. 1996. Tal et a!. Repro Tox. 2015. Tamara Tal, U.S. EPA Tier 10 ED_002061_00269050-00008  One embryo seeded per well o f a 96 well plate Exposed daily (days 0-5) to 8 PFAS compounds On day 6: - DevTox: Malformations and lethality - Dev Neurotoxicity (DNT): Behavioral activity as afunctional readout of DNT - Toxicokinetics: Determine parent and chemical metabolite tissue dose using targeted analytical chemistry and non-targeted analysis r+T+--H r- r F f f F FF? F - F Not for Release Sierra Club v. EPA 18cv3472 NDCA Tamara Tal, U.S. EPA Tier 10 r? o p r r ? r- "l f' PFHsA r- : 7 r F PFM xS F * F < f Vf \ GertX A cid r ; > f."Vv 1 V f " ^ " GertX Saft w T F . 'y o > ' A ' P r ./' 'f y i F" V V / i i ADONA Fv . " - - , ; ' f 1 J A t' V F F ' - t afien P 1 F -V sf 0 --i-- j . .. :y . F- X f X F f 'F ED 002061 00269050-00009  Study on the effects of GenX in the fetal and pregnant Charles River Laboratories (CRSD) rat Pilot study on the effects of in utero GenX in the F I male and female rat offspring using a one generation screening protocol In vitro studies of potential agonist and antagonist interactions with the following steroid receptors Androgen receptor (Chimpanzee) Estrogen receptor (ER a) Glucocorticoid receptor (hGR) for Release Sierra Club v. EPA 18cv3472 NDCA Tier 10 ED 002061 00269050-00010  Toxicity and toxicokinetic testing Ongoing research Integration with risk assessment efforts Mot for Rcilooso Sierra Club v. EPA 18cv3472 NDCA Tier 10 4 1 AV ED 002061_00269050-00011 EPA NIEHS/NTP - John Bucher - Chad Blystone - Mike DeVito - Sue Fenton - Dori Germolec - Eric Tokar US EPA - Rusty Thomas - Kevin Crofton - Tina Bahadori - Jeff Frithsen - Amy Benson - Susan Burden - Lynn Flowers - Linda Gaines US EPA (continued) - Andy Gillespie - Earl Gray - Maureen Gwinn - Ron Hines - Jason Lambert - Pam Noyes - Grace Patlewicz - Stephanie Padilla - Ann Richard - Bruce Rodan - Tim Shafer - Mark Strynar - Tamara Tal - Barbara Wetmore and many others.... Disclaimer: The views expressed in this presentation are that of the presenters and do not necessarily represent the views and/or policies of the U.S. Environmental Protection Agency. ^ * Sierra Club v. EPA 18cv3472 NDCA Tier 10 ED 002061 00269050-00012 Additional Slides Not tor Release Sierra Club v. EPA 18cv3472 NDCA Tier 10 ED_002061_00269050-00013 Endpoint of Interest W Hepatotoxicity Developmental Toxicity Immunotoxicity Mitochondrial Toxicity Developmental Neurotoxicity 2D HepaRG cytotoxicity; 3D HepaRG (spheroid) transcriptomics Bioseek Immune panel 2D HepaRG mitochondrial dye and Seahorse assay Sierra Club v. EPA 18cv3472 NDCA Tier National Center for Computational Toxicology (NCCT) Attagene cis- and trans- Factorial assay (HepG2) National Health and Environmental Effects Research Laboratory (NHEERL) Zebrafish embryo assay Neurodevelopmental microelectrode assay 10 ED 002061 00269050-00014 mai n i n m H m n Human primary hepatocyte clearance Renal proximal tubule permeability assay In Vitro Disposition Cell vs. nominal concentration (Tox21 joint project) O $> i:" 5;%:di v?'%i: Sierra Club v. EPA 18cv3472 NDCA EPA National Center for National Health and Computational Environmental Effects Toxicology Research Laboratory (NCCT) (NHEERL) Ultracentrifugation assay Piloting hepatic transporter assay Cell vs. nominal concentration (Tox21 joint project) Tier 10 ED 002061 00269050-00015