Health Impacts of Emerging Contaminants: A look at GenX ... · Health Impacts of Emerging...
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Health Impacts of Emerging Contaminants: A look at GenX and beyond
Jane Hoppin, ScDAssociate Professor, Biological Sciences
Deputy Director, CHHE
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Emerging ContaminantsUsually not “new” chemicals
Newly measured or newly foundNot regulated
Lack of exposure dataWhat are the chemicals?How do people get exposed? Water? air?
Lack of toxicology dataHalf livesPotential 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?
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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 NCSupplies ~1.5M people with drinking waterLarge ~25 mile long estuary below WilmingtonLarge amount of industry along portions of the river
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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 substancesEnvironmentally persistent
Don’t break down
Some of the chemicals are measured in most peoplePFOA and PFOSNew 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
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
http://www.sixclasses.org/
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
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GenX – Not a Generational Thing
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 GenXmanufacture is captured; it’s still being released as a byproduct
Credit: WUNC
GenXFirst, a byproduct of vinyl ether productionNext, 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 PolyfluorinatedChemicals
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 LettersGenX
GenX Emerging PFASs
GenX concentrations after fluorochemical manufacturer announced on 6/21/2017 that it stopped discharging GenX
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6/21 6/26 7/1 7/6 7/11 7/16 7/21 7/26 7/31 8/5
Gen
X Co
ncen
trat
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(ng/
L)
Finished Water
NC Health Goal140 ng/L
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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
(C6)
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 CompoundsC8 Science Panel Study (Parkersburg, WV)PFOA probably associated with:
Elevated cholesterolUlcerative colitisThyroid diseaseTesticular and kidney cancerPregnancy induced hypertension
Mainly Adults, >45,000 people
PFAS Health EffectsHealth outcomes in children (Rapazzo et al, 2017)
DyslipidemiaImmune function (vaccine response and asthma)Renal functionAge at MenarcheBirth weight (Bach et al, 2015)
Thyroid function (TSH) (Ballesteros et al, 2017)Pregnant WomenBoys
Mainly PFOA and PFOS
December ‘17 – on going
• Analysis continued
July ‘17
• First CommunityMeeting
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
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Home and Clinic VisitHome visit
collected tap water
Clinic visitblood drawurine sample collectionquestionnaireheight and weight measurement
Nov 2017 at New Hanover County Health Department
May 2018 at MLK Center27
Who Participated?
Sample Collection inNovember 2017May 2018
344 individuals289 adults55 children (6-17 years)
Racially diverse76% White10% Black9% Hispanic5% Other
0%
5%
10%
15%
20%
25%
30%
35%
40%
45%
50%
1-5 6-10 11-19 20+
Years in Cape Fear Region
Children Adults
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PFAS we tested for
Newly identified“Legacy”11. GenX12. Nafion byproduct 213. PFMOAA14. PFO4DA15. PFO3OA16. PFO2HxA
1. PFBA2. PFPeA3. PFHxA4. PFHpA5. PFOA6. PFNA7. PFDA8. PFBS9. PFHS10. PFOS17. 6:2 FTS
(tinyurl.com/GenXstudy)
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Groundwater source
Cape Fear River source
Similar GenX concentrations in Sweeney treated water
NC health value (140 ng/L)
Treated water from Sweeney plant,Oct 2-Dec 5, 2017
GenX(ng/L)
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Other fluorochemicals were present
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No pure chemicals were availableAverage mass
spectrometer response
Did we find GenX in blood?No, we did NOT find GenX in blood
Method reporting limit: 2 ng/mL GenX
Sampled ~5 half lives after discharge stopped 50 ng/L GenX in water in Nov 2017<10 ng/L GenX in water in May 2018
NC Dept of Health and Human ServicesGenX NOT in blood from 30 people livingnear Chemours plant
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Newly identified PFAS in Wilmington blood
1. Nafion byproduct 2 (99%)
2. PFO4DA (98%)
3. PFO5DoDA (87%)
OHO
FF
OF
FO
FF
OF
FO
FF
OF
FF
OHS
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O
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F
F
O FF F
F
F FO F
F FF
OH
OF
FOF F
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FOFF
OF
FF
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How do we know about legacy PFAS in US residents?
Centers for Disease Control and Prevention’s National Health and Nutrition Examination Survey (NHANES)
PFOA, PFOS, PFHxS, PFNA, PFDA results are publicly-available
1999-2000 survey (higher exposure)2015-2016 survey (lower exposure)
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PFOA in US residents’ blood
50%
75%
95%
25%
5%
US 1999 (n=1,591)
US 2015 (n=2,170)
Wilmington, NC(n=344)
PFOA concentration(ng/mL)
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50%
75%
95%
25%
5%
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PFOA in US residents’ blood
US 1999 (n=1,591)
US 2015 (n=2,170)
Wilmington, NC(n=344)
PFOA concentration(ng/mL)
50%
75%
95%
25%
5%
Elevated PFOA in Wilmington blood, 2017
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US 1999 (n=1,591)
US 2015 (n=2,170)
Wilmington, NC 2017(n=344)
PFOA concentration(ng/mL)
Why is there elevated PFOA in Wilmington blood?
Historical exposure to high PFOALimited data in lower Cape Fear, 2002-2009
Continued exposure to low PFOA18 ng/L PFOA in Wilmington tap waterUpstream sources
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PFOA PFHxS PFNA PFDAPFOS
Bloo
d co
ncen
trat
ion(
ng/m
L)
Other elevated legacy PFAS in Wilmington
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Nafion byproduct 2
PFO4DA
PFO5DoDA
Median blood concentration for 44 participants (ng/mL)
Nov
embe
r 201
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May
201
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Blood concentrations of newly identified PFAS decreased after six months
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Legacy PFAS levels didn’t change over six months
Median blood concentration for 44 participants (ng/mL)
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PFOS
PFOA
PFHxS
PFNA
PFDANov
embe
r 201
7M
ay 2
018
Emerging Compounds – GenX Case History
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Early-mid 2017: focus on surface water issues
Mid 2017: groundwater issues discovered
Mid-late 2017: air emission contributions
Emerging Compounds – GenX Case History
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Private groundwater wells
>140 ppt GenX10-140 ppt GenXND GenX
Emerging CompoundsDAQ’s investigation involving GenX and other PFAS from Chemours
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Department of Environmental Quality
GenX emissions data Started with only estimatesRequired stack testsMethod developmentFirst of its kind measurements
Chemours 2016 emissions estimates as originally reported to
DAQ
Chemours revised 2016 emissions estimates as
of October 2017
Latest calculations of annual emissions,
including stack test measurements
66.6 lb/yr 594 lb/yr 2302.7 lb/yr
Emerging Compounds – GenX Case History
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Air Emissions Testing or “Stack Testing”• Target compound – C3 Dimer Acid (GenX)• Week of:
• January 8 – PPA & Vinyl Ethers (VE) North• January 22 - PPA & VE North• February 26 - PPA & VE South• March 19 - VE North, Polymers,
Semiworks• April 3 – VE South & VE North for HFPO• April 23 – VE North HFPO• May 14 – Polymers for E1• June 11 – PPA & VE North Carbon bed• July 16 – PPA scrubber efficiency
• VE North carbon bed & Scrubber• July 23 – PPA scrubber &
• carbon bed efficiency
Future testing:August 20 & 27 Scrubber efficiency
No agreement on appropriate methods.But, we knew we could measure it in water.Why not collect rainwater samples to get a sense of atmospheric contributions groundwater issues?Purchased temporary rain collection equipment.Used lab protocols to prepare equipment.
What about ambient air measurements???
Emerging CompoundsDAQ’s investigation involving GenX and other PFAS from Chemours
Summary of facts:
The measured air emissions of GenX compounds are significantly higher than previously understood and reported.
DAQ has measured GenX deposition through rainfall as far as 20 miles from the facility.
The evidence of atmospheric deposition of GenX shows a geographic footprint that is similar to the detection of GenX in groundwater samples.
GenX Exposure Study: Fayetteville
Focusing on both air and water exposuresDust samplesWristband samplesWater Samples
Blood and UrineNon-targeted PFAS
Enrolled participants in February 2019Analyses ongoing
Widespread Impacts
Surface water discharge contaminated the drinking water supply for >250,000 people
Airborne pollutants further impact surface water, groundwater, agriculture, fish, and even honey
Well testing to date shows 763 private wells are contaminated
Rainwater contaminated as far away as Wilmington (>70 miles)
Credit: Wilmington Star News
Lingering Questions
How long were people exposed?GenX released to the river since 1980When did Nafion byproduct 2 start being released?What other chemicals?
How can we estimate exposure levels for chemicals with short half lives?Are the chemicals in the air the same as in the river?Now that exposure sources have been controlled, how can we estimate exposures?Exposure is not just to one chemical, but a mixture of chemicals
Next Steps
Analyze collected samplesAre the chemical exposures the same in Wilmington and Fayetteville?
Look at health outcome dataThyroidCholesterolLiver functionBMIRespiratory symptoms and diseaseCytokine response
GenX Exposure Study TeamNC State
Jane Hoppin, PIDetlef KnappeNadine KotlarzKaty MayRob Smart
ECUDavid CollierJamie DeWittSuzanne Lea
EPAAndrew LindstromJames McCordMark Strynar
New Hanover County Health Department
Phillip TarteKatelyn Matney
Cape Fear River WatchKemp BurdetteMadi PoleraAmanda BoomershineLarry Cahoon
Community Science Advisory Panel
Funding: NIEHS R21 R21ES029353CHHE P30ES025128Matching Funds from NC Policy Collaboratory 58
GenX Exposure Study: Responding to Community Concerns
Community wants to know:Is GenX detectable in me?
What factors influence GenX concentration?
Is GenX associated with health effects?
1980: Chemours begins discharging GenX, a perfluoroalkyl substance (PFAS)
2017: GenX detected in Cape Fear River, City of Wilmington’s finished drinking waterNow: Exposure reduced, but community concerned about health impacts
The GenX Exposure StudyPartners: Cape Fear River Watch, New Hanover County Health Dept.Enrolled: >300 residents, ages 6+, November 2017Measuring: GenX in drinking water, blood, urineCommunication: Utilizing Community Science Advisory Panel for report backPI: Hoppin R21 ES029353
Wilmington, NCSun et al. ES&T letters 2016