health impacts of emerging contaminants: a look at genx ... health impacts of emerging contaminants:

Download Health Impacts of Emerging Contaminants: A look at GenX ... Health Impacts of Emerging Contaminants:

Post on 09-Mar-2020




0 download

Embed Size (px)


  • Health Impacts of Emerging Contaminants: A look at GenX and beyond

    Jane Hoppin, ScD Associate Professor, Biological Sciences

    Deputy Director, CHHE


  • Outline

    Emerging Contaminants What are they?

    GenX background Potential Health Outcomes

  • Emerging Contaminants Usually not “new” chemicals

    Newly measured or newly found Not regulated

    Lack of exposure data What are the chemicals? How do people get exposed? Water? air?

    Lack of toxicology data Half lives Potential health effects

    Lack of human health information

  • No specific limit in environmental regulations. Sparse knowledge about how they behave in the environment. Little known about their effects on human health and environment.

    Significant challenge for regulatory agencies. How to prioritize? Research? Minimize impacts? Communicate?


    What do we mean when we say Emerging Compounds?

  • Unknown Characteristics of “Emerging” Fluorinated Compounds

    Actual identities of alternatives unknown in industrial sectors and geographical regions that are not well regulated

    Data on environmental and human health effects are incomplete (at best) and more often nonexistent

    Data on degradability, bioaccumulation, and toxicity (environmental and human) are incomplete (at best) or completely lacking

    Information on production volume and environmental emissions not available

    Wang et al. Environment International 2013, 60, 242−248

  • Largest watershed in NC Supplies ~1.5M people with drinking water Large ~25 mile long estuary below Wilmington Large amount of industry along portions of the river


  • PFAS in River AND Drinking Water Detlef Knappe,NCSU Mark Strynar, USEPA Andy Lindstrom, USEPA

  • Wilmington Star News, June 7, 2017

  • 9

  • Community forums with local scientists, environmental advocates, utility representatives, DEQ / DHHS, academia, and public health experts

    Intensive media coverage, including state-wide and national attention

    Considerable interest by local, state, and national elected officials

    Community Response

  • PFAS Chemicals

    Per- and poly-fluoroalkyl substances Environmentally persistent

    Don’t break down

    Some of the chemicals are measured in most people PFOA and PFOS New chemicals we don’t know much about

  • Two types of PFAS have been heavily studied  “Legacy Compounds”

    Perfluorooctane sulfonate (PFOS)

    Perfluorooctanoic acid (PFOA / C8)

    Common uses: Goretex, Teflon

    Common uses: Firefighting, stain repellent

    Presenter Presentation Notes PFCs work well as surfactants because of the hydrophilic acid head and hydrophobic carbon-fluorine tail that can not only repel water but also fats and oils. The hydrophobic/hydrophilic characteristic, as well as high water solubility and low volatility, contribute to the presence of PFCs in all aquatic environments and even in rain water.

  • Non-stick coatings

    Grease- and oil-resistant coatings for paper products

    Water repellent fabrics

    Stain-resistant coatings for fabrics, carpets, and leather

    Firefighting foams

    PFASs are released into the environment by:

    the manufacturing process, and the use of products containing PFASs

    Presenter Presentation Notes Firefighting agents are probably one of the products that contribute the most to PFC emissions because of the direct introduction of PFCs into the environment when extinguishing fires. Coated textiles are another important source since PFCs can be released during cleaning or through wear.

  • Trends in PFAS Serum Levels in US

    Sagiv et al. Environmental Science & Technology 2015, 49, 11849−11858

  • GenX = C3 Dimer Acid = C6HF11O3 GenX is a trade name for a man-made and unregulated chemical used in manufacturing nonstick coatings and for other purposes.

    In a family of chemicals known as per- and poly- fluorinated alkyl substances (PFAS) Produced and emitted by one company in NC – Chemours (formerly Dupont) Has been discharged into the Cape Fear River for 30+ years (since 1980) Until the past couple of years, labs couldn’t measure it. DHHS Public Health Goal = 140 ppt in water


    GenX – Not a Generational Thing

    Presenter Presentation Notes So.. What is Genx? No, its not just a generational thing. C3 Dimer Acid or C6HF11O3. GenX is a trade name…..

    EPA monitoring, 2013-2015 via the Third Unregulated Contaminant Monitoring Rule (UCMR) Found 28 chemicals EPA and NCSU, 2014-2016, study PFOA, PFOS and other per- and poly-fluorinated chemicals in the Cape Fear River. Research findings published in Nov. 2016 on PFOA/PFOS, GenX and other related chemicals attributed to the Chemours (formerly DuPont) facility just south of Fayetteville, NC.

    With growing concerns about the potential public health impacts, 11/14/18, EPA published draft reference doses and draft toxicity assessments for GenX compounds and perfluorobutane sulfonic acid (PFBS).

  • History of Contamination

    1980 - Contamination begins with Dupont – GenX released as a byproduct

    Around 2000 - DuPont begins manufacture of Teflon using C8 (PFOA); GenX will be its replacement

    2009 Parkersburg consent order requires all wastewater from GenX manufacture is captured; it’s still being released as a byproduct

    Credit: WUNC

  • GenX First, a byproduct of vinyl ether production Next, an identified ingredient to replace PFOA in Teflon production

    Identity originally protected as Confidential Business Information (CBI)

    Still persistent, still toxic, but less bioaccumulative than C8

    DuPont studies found effects on rats similar to C8, including possible endocrine/immune disruption, enlarged livers and kidneys, and cancer

    Approved by the EPA, no further testing required

  • Sun et al. Environmental Science & Technology Letters 2016, 3, 415−419

    Not just GenX:

    Family of Per- and Polyfluorinated Chemicals

  • Legacy PFAS with GenX in Cape Fear River Basin

    Sun et al. Environmental Science & Technology Letters 2016, 3, 415−419

  • Other similar substances occur at much higher concentrations than legacy PFASs and GenX

    Sun et al. (2016) ES&T Letters GenX

    GenX Emerging PFASs

    Presenter Presentation Notes Bill, these concentrations are estimated from the GenX response as we do not yet have authentic standards apart from GenX

  • GenX concentrations after fluorochemical manufacturer announced on 6/21/2017 that it stopped discharging GenX










    6/21 6/26 7/1 7/6 7/11 7/16 7/21 7/26 7/31 8/5

    G en

    X Co

    nc en

    tr at

    io n

    (n g/


    Finished Water

    NC Health Goal 140 ng/L


  • What are the potential health effects of GenX?

  • We have some data for humans

    We often rely on animal models to inform these…

    Once we are exposed to PFASs, some can stay in the body for a long time

    Compound Half-life(Human) Half-life

    (Female Rat) Half-life

    (Male Rat)

    PFOA (C8) 3.8 years 4 hours 6 days

    GenX ?????? 2.9 days

    But animal models don’t

    seem to be great predictors here.

    Compound PFOA (C8) PFOS PFHxA


    Half-Life (Human) 3.8 years 5.4 years 32 days

    C6 is the most similar to GenX,

    and gives us our best guess at

    its half-life

  • Human Health Data Available for Related Compounds C8 Science Panel Study (Parkersburg, WV) PFOA probably associated with:

    Elevated cholesterol Ulcerative colitis Thyroid disease Testicular and kidney cancer Pregnancy induced hypertension

    Mainly Adults, >45,000 people

  • PFAS Health Effects Health outcomes in children (Rapazzo et al, 2017)

    Dyslipidemia Immune function (vaccine response and asthma) Renal function Age at Menarche Birth weight (Bach et al, 2015)

    Thyroid function (TSH) (Ballesteros et al, 2017) Pregnant Women Boys

    Mainly PFOA and PFOS

  • December ‘17 – on going

    • Analysis continued

    July ‘17

    • First Community Meeting

    August ‘17

    • Grant Submitted

    November ‘17

    • Grant Funded • Data Collection

    April ‘18

    • Water report-back

    Designed to answer community questions about GenX and related PFAS exposure

    Are PFAS detectable in my body? What predicts PFAS in my body? Are there health effects associated with PFAS?

    Funded by NIEHS through their time sensitive grants program.

    GenX Exposure Study: Responding to Community Concerns

    May ‘18

    • New enrollment • Resampling

    Oct ‘18

    • Clinical report- back letter

    Nov ‘18

    • PFAS blood report-back


  • Home and Clinic Visit Home visit

    collected tap water

    Clinic visit blood draw urine sample collection questionnaire height and weight measurement

    Nov 2017 at New Hanover County H


View more >