PFAS Occurrence in NC...PFAS Occurrence in North Carolina Detlef Knappe Professor Dept. of Civil,...
Transcript of PFAS Occurrence in NC...PFAS Occurrence in North Carolina Detlef Knappe Professor Dept. of Civil,...
PFAS Occurrence in North Carolina
Detlef KnappeProfessorDept. of Civil, Construction, and Environmental EngineeringNorth Carolina State [email protected]
1NC Secretaries’ Science Advisory Board MeetingRaleigh, NC, December 7, 2020
Outline
• Brief introduction to per- and polyfluoroalkyl substances (PFASs)
• PFAS occurrence in NC drinking water sources• PFAS occurrence in blood serum of North Carolinians• Key observations
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What are per- and polyfluoroalkyl substances (PFASs)?
• Class of synthetic chemicals that includes several thousand compounds
• Perfluoroalkyl substances: all C-H bonds replaced by C-F bonds
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Perfluoroalkyl carboxylic acids (PFCAs) (e.g. perfluorooctanoic acid, PFOA or C8)
Perfluoroalkyl sulfonic acids (PFSAs)(e.g. perfluorooctane sulfonic acid, PFOS)
H
What are per- and polyfluoroalkyl substances (PFASs)?
• Polyfluoroalkyl substances: not all C-H bonds replaced by C-F bonds
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Ø Perfluorooctane sulfonic acid (PFOS)
Ø 6:2 Fluorotelomersulfonic acid (6:2 FtS)
Perfluorinated(no C-H bonds)
Polyfluorinated(contains C-H bonds)
H
What are per- and polyfluoroalkyl substances (PFASs)?
• Per- and polyfluoro ether acids (“fluoroethers”) contain at least one ether oxygen atom
“GenX”PFMOAA
PMPA
PEPA
PFO2HxA PFO4DA
PFPrOPrA, HFPO-DA
Nafion by-product 2
Some common PFAS uses
Non-stick coatings
Grease- and oil- resistant coatings for paper products
Water repellent fabrics
Stain-resistant coatings for fabrics, carpets, and leather
Aqueous film forming foams
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PFASs are known contaminants in some North Carolina drinking water sources
PFAS Sources:Ø Industrial wastewater discharges and air
emissionsFluorochemical production
Ø Municipal wastewater discharges and land application of biosolids
Landfill leachateIndustrial pretreatment
Ø Aqueous film-forming foam (AFFF)Military basesFirefighting training areasAirports
Impacts:Ø PFAS-impacted private and
public drinking water wellsØ PFAS-impacted surface waterØ Water treatment burdenØ Community concerns
Map courtesy of NC StateCenter for Geospatial Analytics(Vaclav Petras and Helena Mitasova)
Statewide sample collection
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Raw drinking water sampled from every NC Public Drinking Water Provider for PFAS quantitation, 2 rounds
Ø 191 municipal surface water sitesØ 149 municipal ground water sitesØ 58 county water sites
Round 1 : COMPLETED
Round 2: In Progress
PFBS
APF
HxSA
PFO
SANM
eFO
SAA
NEtF
OSA
A4:
2 PF
S6:
2 PF
S8:
2 PF
S10
:2 P
FSPF
BAPF
PeA
PFHx
APF
HpA
PFOA
PFNA
PFDA
PFUn
DAPF
DoDA
PFTr
DAPF
TeDA
PFHx
DAPF
MOA
APM
PAPE
PAPF
O2H
xAPF
O3O
APF
O4D
APF
O5D
oDA
Gen
XNV
HOS
ADO
NAHy
dro−
EVE
acid
Nafio
n by−p
rodu
ct 1
Nafio
n by−p
rodu
ct 2
Nafio
n by−p
rodu
ct 4
F−53
B (M
inor
)F−
53B
(Maj
or)
PFBS
PFPe
SPF
HxS
PFHp
SPF
OS
PFNS
PFDS
PFDo
SN−
AP−F
HxSA
N−TA
mP−
FHxS
AN−
CMAm
P−6:
2FO
SA (6
:2 F
TAB)
1
2
5
10
20
50
100
200
500
Conc
entra
tion
(ng/
L)
% Detected
% ND
EPA HAL (PFOA & PFOS) = 70 ng/L
NC DHHS HAL (GenX) = 140 ng/L
Quantified PFAS Summary (n = 376)
Fluoroalkyl sulfonamides (FASAs)
Fluorotelomer Sulfonates
Perfluoroalkylcarboxylic acids (PFCAs)
Perfluoroalkylether Acids (PFEAs)
Perfluoroalkylsulfonic Acids (PFSAs)
Zwitterions
Concentration (ppt)
0 100 200 300 400
EPA PFOS+PFOA Health Advisory Level
Wat
er s
tatio
n (n
= 3
76 s
ites)
Summary of Round 1 Testing of 376 Drinking Water Supplies in NC
20 public water supplies with SPFAS > 70 ng/L
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Comparison of Round 1 and 2: High temporal variability of PFAS levels in the Haw River at Pittsboro
Round 1 4/9/19ΣPFAS 54.3 ng/LDischarge 4,120 ft3/sPrecip. (14d) 1.66”
Round 2 9/5/19ΣPFAS 837.4 ng/LDischarge 119 ft3/sPrecip. (14d) 0.70”
Dominant PFASs in 57 private wells near Chemours
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Median (ng/L)
GenX PEPA PFMOAAPFO2HxAPMPA
OH
OF
F
OF FF
OH
OFOFF
F
FFF
OH
OFO
F FFFFF
F
FFF
OH
OF
F
OF FOF
FF
OH
OFO
F FFF
F
FFF
GenX Exposure Study, NCSU, unpublished data
What were the PFAS levels in Wilmington drinking water?
PFMOAA
PFO2HxA
PFO3OAPFO4DA
PFO5DoA PMPA PEPA GenX Nafion by-product 2
NVHOSHydroEVEPFBA
PFPeA
PFHxA
PFHpA
PFOA
PFHxS
PFOS
S PFCAs: 120 ng/L
S PFSAs: 45 ng/L
S Fluoroethers: 130,000 ng/L
Zhang et al. (2019) ES&T Letters
July 2015 sample
PFAS occurrence in blood serum of North Carolinians
• NCSU/ECU GenX Exposure Study: Wilmington (Kotlarz et al., EHP, 2020)
• Duke University: Pittsboro
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Wilmington, NC
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PFHxSPFOSPFHpAPFOAPFNANafion BP2PFO4OAPFO5DoA
PFOS37%PFOA
19%
PFHxS19%NBP2
12%
PFO4DA12%
344 people living in Wilmington were recruited in November 2017
• 127 men, 216 women, 1 transgender• 289 adults, 55 children• Ages ranged from 6-86; median 50
PFNA5%
Kotlarz et al., EHP, 2020
Pittsboro, NC
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PFAS in SerumPFHxA
PFHxS
PFHpA
PFOA
PFOS
PFNA
PFDA
PFOS:48%
PFOA:27%
PFHxS:12%
PFNA6%
49 people living in Pittsboro were recruited in November 2019
• 18 men and 31 women• Ages ranged from 33-86; median 60
Data from Heather Stapleton, Duke University
Key Observations
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20 PFASs with highest detection frequencies and/or highest concentrations
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Drinking Water Blood Serum
Perfluoroalkyl carboxylic acids PFBA, PFPeA, PFHxA, PFHpA, PFOA
PFHxA, PFHpA, PFOA, PFNA, PFDA
Perfluoroalkyl sulfonic acids PFBS, PFHxS, PFOS PFHxS, PFOS
Perfluoroalkyl ether carboxylic acids PFMOAA, PMPA, PEPA, GenX, PFO2HxA, PFO3OA, PFO4DA
PFO4DA, PFO5DoA, HydroEVE
Perfluoroalkyl ether sulfonic acids Nafion by-product 2
PFASs in both the drinking water and blood serum columns are important from an exposure perspective.
PFAS levels in blood serum of people living in Wilmington are higher than those of the general US population
19PFOA PFHxS PFNA PFDA PFOS
Bloo
d se
rum
con
cent
ratio
n(ng
/mL)
Kotlarz et al., EHP, 2020
NHANES (general US)
Wilmington, NC
PFAS levels in blood serum of people living in Pittsboro are higher than those of the general US population
20Data from Heather Stapleton, Duke University
Elevated PFAS levels in blood serum are likelyassociated with PFAS exposure through drinking water
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Time (years)
Wilmington median
Seru
m P
FOA
(ng/
mL)
Predictedfor 18 ng/L PFOA in
drinking water
Data from Kotlarz et al. (2020) PFAS calculator: https://www.ics.uci.edu/~sbartell/pfascalc.html
Median fluoroether levels in blood serum of people in Wilmington decreased after levels in drinking water dropped
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Nafion byproduct 2
PFO4DA
PFO5DoDA
Median blood serum concentration for 44 participants (ng/mL)
Nove
mbe
r 201
7
May
201
8
Kotlarz et al., EHP, 2020
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PFASs occur as mixtures in water…
Cape Fear River: Chemours Impact PFSAs
PFOS
PFCAsPFOA
FASAs
FTSs
PFEAs
Lake Brandt:AFFF Impact PFSAs
PFOS
PFCAsPFOA
FASAs
FTSs
PFEAs
Cane Creek Reservoir:Biosolids Impact PFSAs
PFOS
PFCAsPFOA
FASAs
FTSs
PFEAs
Haw River: Industrial Wastewater Impact PFSAs
PFOS
PFCAsPFOA
FASAs
FTSs
PFEAs
… and in people
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PFHxSPFOSPFHpAPFOAPFNANafion BP2PFO4OAPFO5DoA
PFOS37%PFOA
19%
PFHxS19%NBP2
12%
PFO4DA12%
PFNA5%
Kotlarz et al., EHP, 2020
Take-Home MessagesØ 20 PFASs are frequently detected and/or detected at high
concentrations in NC drinking water sources and/or blood serum of North Carolinians
Ø PFAS levels in blood serum of North Carolinians living in the Cape Fear River basin are substantially higher than in the general US population
Ø Drinking water is an important exposure route
Ø PFASs occur in mixtures
Ø Sources of PFAS contamination varyv Fluorochemical manufacturing (air emissions, wastewater, contaminated groundwater
discharging to surface water)v Industrially impacted municipal wastewater and biosolidsv Aqueous film-forming foam
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Thank you for listening!
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Acknowledgements:
Research Funding:• NIEHS (GenX Exposure Study)• NC Policy Collaboratory (PFAST)
Data Contributions:• Jane Hoppin (NCSU)• Heather Stapleton (Duke University)• Lee Ferguson (Duke University)