health impacts of emerging contaminants: a look at genx ... health impacts of emerging contaminants:
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Health Impacts of Emerging Contaminants: A look at GenX and beyond
Jane Hoppin, ScD Associate Professor, Biological Sciences
Deputy Director, CHHE
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
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
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.
Grease- and oil-resistant coatings for paper products
Water repellent fabrics
Stain-resistant coatings for fabrics, carpets, and leather
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
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
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
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
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
• First Community Meeting
• Grant Submitted
• Grant Funded • Data Collection
• 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
• New enrollment • Resampling
• Clinical report- back letter
• 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