Supporting information

Perfluoroalkyl substances in sediments from the Bering Sea to the

western Arctic: Source and pathway analysis

Yan Lin1,2,5, Jheng-jie Jiang3, Lisa A. Rodenburg4, Minggang Cai1,2,5 *, Zhai Wu5, Hongwei

Ke1,5, Mahdi Chitsaz4

1 State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361102

2 Fujian Provincial Key Laboratory for Coastal Ecology and Environmental Studies, Xiamen University,

Xiamen 361102

3 Department of Environmental Engineering, Chung Yuan Christian University, Taoyuan, 32023

4 Department of Environmental Sciences, Rutgers University, New Brunswick 08901

5 College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102

Contents

Table S1. Information about the sampling sediment ......................................................................... 3

Table S2. Basic parameters of surface sediments .............................................................................. 4

-: Not detected; C/N: TOC/TN .......................................................................................................... 5

Table S3. Gradient elution program of chromatographic separation. ............................................... 6

Table S4. LC-MS/MS operation parameters. .................................................................................... 6

Table S5. The 9 compounds, their MRM pairs, LOD and LOQ. ...................................................... 7

Table S6. Information about the PFAS standard ............................................................................... 8

Table S7. Calculation of concentrations and related magnitudes for core S03. ................................ 9

The explanation of the terms in Table S7 ........................................................................................ 12

z(i): depth of layer (i) (m), experimentally determined. Note that z(0) = 0 m. ............................... 12

Table S8. Concentrations of PFASs in the surface sediments from the study area (ng/g dw) ......... 13

Table S9. PFAS levels in sediment from different regions .............................................................. 15

Table S10. Pearson correlation of PFAS levels with basic sediment parameters ............................ 16

Table S11. Concentrations of PFASs in the sediment core S03 (ng/g dw) ...................................... 17

Table S12. Factor Profiles (% of species sum) from PMF model ................................................... 18

Fig. S1. PCA and HCA results of PFASs in sediments of the western Arctic and Bering Sea. ....... 19

Table S1. Information about the sampling sediment

Station Longitude Latitude Date Depth (m)

B12 181.14 60.69 2016/9/9 70

NB02 184.47 60.87 2014/7/23 107

NB04 188.73 61.20 2014/7/23 57

B13 182.52 61.29 2014/7/22 132

B14 183.60 61.93 2014/7/25 105

B15 184.69 62.54 2014/7/25 79

R03 191.15 67.53 2016/9/4 49

R02 191.00 67.67 2014/7/28 50

CC2 191.76 67.91 2014/7/28 58

R04 191.19 68.21 2016/9/4 57

C03 193.52 69.03 2014/7/29 32

C01 191.86 69.22 2014/7/30 50

R05 191.00 71.00 2014/7/30 43

S01 202.07 71.62 2014/8/2 63

C24 199.17 71.82 2016/9/1 45

S03 202.92 72.23 2014/8/3 169

C22 195.12 72.33 2016/9/1 47

S11 198.53 72.44 2016/8/31 44

C21 193.26 72.60 2016/9/1 52

R08 190.10 74.00 2014/8/1 179

R09 190.97 74.61 2014/8/1 190

P23 207.52 75.04 2016/7/30 1 999

E21 180.19 75.15 2016/8/21 538

R11 193.80 76.15 2014/8/8 352

R16 190.83 77.12 2016/8/22 1879

ICE03 163.14 77.49 2014/8/13 466

E24 180.09 77.90 2016/8/19 1569

P11 194.07 78.51 2016/8/3 543

R14 199.57 78.63 2014/8/15 761

Table S2. Basic parameters of surface sediments

Station WC (%) BC (%) TOC (%) δ13C (‰) C/N Clay (%) Silt (%) Fine sand (%) Corse sand (%)

B12 52.43 0.13 1.69 -21.15 12.87 16.68 80.71 2.21 0.04

NB02 59.66 0.54 1.61 -19.81 8.38 3.47 84.39 11.98 0.17

NB04 27.04 - - - - 3.86 85.81 10.15 0.18

B13 46.40 0.10 0.96 -21.73 13.13 3.24 84.31 10.19 2.25

B14 55.64 0.15 1.79 -20.81 12.11 5.09 76.15 18.04 0.72

B15 43.76 0.09 1.14 -21.59 11.54 5.74 83.72 9.63 0.92

R03 38.72 0.18 1.34 -20.29 10.24 0.00 55.50 11.17 33.33

R02 41.31 0.10 0.98 - - 3.16 79.41 17.01 0.42

CC2 34.58 0.09 1.11 -21.89 13.69 3.04 55.22 10.53 31.21

R04 46.54 0.06 1.27 - - 5.89 74.48 14.46 5.17

C03 35.24 0.11 0.66 - - 2.66 63.50 31.23 2.63

C01 49.78 0.30 1.46 -22.28 13.50 4.39 69.95 25.21 0.45

R05 39.52 0.10 1.15 - - 7.72 84.86 7.19 0.22

S01 51.20 0.22 2.09 -22.10 13.67 7.26 83.75 8.78 0.20

C24 0.21 1.46 -20.54 14.94 7.88 85.54 6.57 0.00

S03 63.96 0.39 1.78 -21.75 12.60 5.14 89.56 5.16 0.13

C22 48.43 0.51 1.73 -20.46 11.60 5.53 92.43 2.05 0.00

S11 57.85 0.10 1.78 -19.47 9.88 3.97 93.64 2.37 0.02

C21 57.87 0.14 2.04 -20.27 12.58 6.80 82.61 5.63 4.95

R08 59.94 0.13 0.89 -20.83 12.80 5.23 81.12 4.46 9.20

R09 50.91 0.11 0.94 - - 13.25 81.61 5.13 0.00

P23 52.74 0.09 0.61 -23.07 10.96 - - - -

E21 51.19 0.11 0.64 -21.00 12.34 27.14 70.53 1.11 0.13

Station WC (%) BC (%) TOC (%) δ13C (‰) C/N Clay (%) Silt (%) Fine sand (%) Corse sand (%)

R11 55.16 0.19 0.94 -21.35 11.57 15.74 79.31 5.13 0.00

R16 46.83 0.18 1.25 -22.99 9.49 22.36 45.08 1.14 32.56

ICE03 47.71 0.11 0.60 - - 21.87 74.84 0.00 0.00

E24 48.30 0.09 0.60 -21.88 10.18 24.43 72.55 3.29 0.00

P11 50.72 0.11 0.68 -21.82 10.46 12.51 85.05 3.02 0.00

R14 50.30 0.11 0.63 -22.39 8.20 28.16 71.05 2.44 0.00

-: Not detected; C/N: TOC/TN

Table S3. Gradient elution program of chromatographic separation.

Eluent

Mobile phase A: 0.1% formic acid in DI water

Mobile phase B: 0.1% formic acid in methanol

Flow rate: 350 μL/min

Time (min) Mobile phase

A (%) B (%)

0.0 70 30

0.1 70 30

1.5 20 80

4.0 5 95

9.0 5 95

9.2 70 30

13 70 30

Table S4. LC-MS/MS operation parameters.

Ionization mode ESI Negative Mode

Dwell time 50 ms

Ion Spray Voltage (S) -4.5kV

Curtain Gas (CUR) 10 L/h

Gas 1 (GS1) 50 L/h

Gas 2 (GS2) 60L/h

Temperature 500℃

Interface Heater (ihe) ON

Collisionally Activated 5

Dissociation

Table S5. The 9 compounds, their MRM pairs, LOD and LOQ.

Chemical

LOD LOQ

(ng/g)

blank and matrix

spike recoveries MRM1

(quantification)

MRM2

(confirmation) (ng/g) (%)

PFBS 0.02 0.06 93 ± 4 299/80 299/99

PFHxS 0.02 0.06 90 ± 4 399/80 399/99

PFOS 0.03 0.09 99 ± 0 499/80 499/99

PFHpA 0.33 1.0 85 ± 2 363/319 363/169

PFOA 0.01 0.03 86 ± 3 413/369 413/169

PFNA 0.01 0.03 83 ± 4 463/419 463/219

PFDA 0.01 0.03 73 ± 4 513/469 513/269

PFUnA 0.01 0.03 76 ± 2 563/519 563/269

PFDoA 0.01 0.03 81 ± 2 613/569 613/269

LOD: Limits of detection; LOQ: Limits of quantification.

Table S6. Information about the PFAS standard

number Compound Original concentrations Purification

(%)

Company

1 13C8-PFOA 50 μg/mL >99 Cambridge Isotope Laboratories (Andover, MA, USA）

2 13C9-PFNA 50 μg/mL >99 Cambridge Isotope Laboratories (Andover, MA, USA）

3 PFDA 50 μg/mL >99 Cambridge Isotope Laboratories (Andover, MA, USA）

4 PFUnA 50 μg/mL >99 Cambridge Isotope Laboratories (Andover, MA, USA）

5 PFOS 1000 μg/mL >99 Absolute Standards (Hamden, CT, USA)

6 PFHxS 1000 μg/mL >99 Absolute Standards (Hamden, CT, USA)

7 PFBS 1000 μg/mL >99 Absolute Standards (Hamden, CT, USA)

8 PFNA 1000 μg/mL >99 Absolute Standards (Hamden, CT, USA)

9 PFOA 1000 μg/mL >99 Absolute Standards (Hamden, CT, USA)

10 PFHpA 1000 μg/mL >99 Absolute Standards (Hamden, CT, USA)

11 PFDoA 1000 μg/mL >99 Absolute Standards (Hamden, CT, USA)

Table S7. Calculation of concentrations and related magnitudes for core S03.

z(i) zi

∆mi/S Used 209Po

209Po

counting

210Po

counting 210Pb

210Pb

uncertainty

Ci

∆Ai

A(i)

t (i) r (i) Year

(cm) (cm) g cm-2 (dpm) (cpm) (cpm) (dpm/g) (dpm/g) Bq/m-2 Bq/m-2 Bq/m-2 (yr) (g cm-2 yr-1) (A.D.)

0 13992 0.0 0.55 2014.8

0.5 1.93 7.48 2879 4155 5.39 0.15 72.17 1212

1 12780 2.9 0.48 2011.8

1.5 1.88 7.48 2187 2452 5.58 0.18 75.33 1231

2 11549 6.2 0.44 2008.6

2.5 2.22 7.48 2478 2690 5.39 0.16 72.13 1398

3 10151 10.3 0.41 2004.4

3.5 2.22 7.48 2346 2389 5.06 0.16 66.66 1287

4 8864 14.7 0.39 2000.1

4.5 2.10 7.48 2834 2278 4.79 0.15 62.12 1138

5 7727 19.1 0.34 1995.7

5.5 2.12 7.48 2181 2066 4.71 0.16 60.86 1125

6 6601 24.1 0.30 1990.6

6.5 2.10 7.48 1900 1706 4.48 0.16 56.91 1043

7 5558 29.7 0.32 1985.1

7.5 2.28 7.48 1931 1458 3.76 0.14 44.92 891

8 4667 35.3 0.51 1979.5

8.5 2.34 7.48 2949 1530 2.58 0.09 25.39 518

9 4149 39.0 0.43 1975.7

9.5 2.20 7.48 1953 777 2.65 0.12 26.49 508

z(i) zi

∆mi/S Used 209Po

209Po

counting

210Po

counting 210Pb

210Pb

uncertainty

Ci

∆Ai

A(i)

t (i) r (i) Year

(cm) (cm) g cm-2 (dpm) (cpm) (cpm) (dpm/g) (dpm/g) Bq/m-2 Bq/m-2 Bq/m-2 (yr) (g cm-2 yr-1) (A.D.)

10 3641 43.2 0.30 1971.5

10.5 2.25 7.48 2912 1736 2.96 0.10 31.64 621

11 3020 49.2 0.36 1965.5

11.5 2.23 7.48 2803 1814 2.41 0.08 22.53 438

12 2582 54.3 0.50 1960.5

12.5 2.43 7.48 2770 1063 1.91 0.07 14.18 300

13 2282 58.2 0.46 1956.5

13.5 2.31 7.48 2560 838 1.87 0.08 13.50 272

14 2010 62.3 0.27 1952.4

14.5 2.43 7.48 2289 1328 2.17 0.08 18.42 389

15 1621 69.2 0.23 1945.5

15.5 2.34 7.48 2760 1154 2.08 0.08 17.07 348

16 1273 77.0 0.21 1937.8

16.5 2.18 7.48 1781 927 1.94 0.08 14.73 280

17 993 85.0 0.56 1929.8

17.5 2.51 7.48 2248 612 1.35 0.06 4.90 107

18 886 88.6 0.47 1926.1

18.5 2.35 7.48 2095 602 1.37 0.07 5.18 106

19 780 92.7 0.21 1922.0

19.5 2.42 7.48 2179 695 1.59 0.07 8.83 186

20 594 101.5 0.18 1913.3

20.5 2.40 7.48 2372 722 1.52 0.07 7.61 159

z(i) zi

∆mi/S Used 209Po

209Po

counting

210Po

counting 210Pb

210Pb

uncertainty

Ci

∆Ai

A(i)

t (i) r (i) Year

(cm) (cm) g cm-2 (dpm) (cpm) (cpm) (dpm/g) (dpm/g) Bq/m-2 Bq/m-2 Bq/m-2 (yr) (g cm-2 yr-1) (A.D.)

21 435 111.5 0.11 1903.3

21.5 2.49 7.48 1731 699 1.51 0.07 7.41 161

22 274 126.3 0.10 1888.4

22.5 2.55 7.48 1994 550 1.37 0.07 5.16 114

23 159 143.7 0.37 1871.0

23.5 2.63 7.48 2357 383 1.13 0.06 1.12 26

24 134 149.3 0.05 1865.4

24.5 2.65 7.48 1791 606 1.26 0.06 3.37 78

25 56 177.3 1837.4

25.5 2.43 7.48 2069 507 1.22 0.06 2.65 56

26

26.5 2.62 7.48 3158 674 1.06 0.05

27

27.5 2.59 7.48 1755 601 1.28 0.06

28

28.5 2.39 7.48 3406 757 1.11 0.05

29

29.5 2.36 7.48 2411 557 1.15 0.06

30

30.5 2.23 7.48 2589 570 1.09 0.05

31

31.5 2.40 7.48 3731 816 1.09 0.04

z(i) zi

∆mi/S Used 209Po

209Po

counting

210Po

counting 210Pb

210Pb

uncertainty

Ci

∆Ai

A(i)

t (i) r (i) Year

(cm) (cm) g cm-2 (dpm) (cpm) (cpm) (dpm/g) (dpm/g) Bq/m-2 Bq/m-2 Bq/m-2 (yr) (g cm-2 yr-1) (A.D.)

32

32.5 2.49 7.48 2925 587 1.00 0.05

33

The explanation of the terms in Table S7

z(i): depth of layer (i) (m), experimentally determined. Note that z(0) = 0 m.

– zi: mean depth of section i (m), where zi = [z(i-1) + z(i-1)]/2

– ∆mi: dry mass of section i (g), experimentally determined.

– S: Area in section i (cm-2), experimentally determined

– Ci: 210Pbex concentration in section i (Bq kg-1), experimentally determined.

– ∆Ai: 210Pbex deposit (or activity per unit surface area) in section i (Bq m-2), computed as: ∆Ai = Ci ∆mi/S

– A(i): accumulated deposit below layer (i) (Bq m-2): 𝐴(𝑖) ∑ ∆Aj𝑗=∞𝑗=𝑖+1

– t(i): time elapsed since formation of layer (i) (yr). Note that t(0) = 0 yr.

– r(i): mass accumulation rate layer (i) (g cm-2 yr-1)

Table S8. Concentrations of PFASs in the surface sediments from the study area (ng/g dw)

Station PFBS PFHxS PFOS PFHpA PFOA PFNA PFDA PFUnA PFDoA

NB02 n.d 0.05 0.19 n.d n.d 0.38 0.03 0.01 n.d

NB04 n.d n.d 0.04 n.d n.d 0.02 n.d n.d n.d

B13 0.28 0.30 0.60 n.d 0.03 0.51 0.01 n.d n.d

B14 0.14 n.d 0.15 n.d n.d 0.18 n.d n.d n.d

B15 0.25 n.d 0.31 n.d 0.04 0.29 n.d n.d n.d

B12 0.06 0.44 0.43 n.d n.d 0.01 0.01 n.d n.d

R03 0.09 0.24 0.20 n.d 0.02 0.28 0.03 n.d n.d

R02 0.02 n.d 0.16 n.d n.d 0.23 0.02 n.d n.d

CC2 0.31 0.11 0.14 n.d n.d 0.26 0.01 n.d n.d

R04 0.08 0.16 0.40 n.d n.d 0.05 0.01 n.d n.d

C03 0.04 0.18 0.13 n.d 0.02 0.24 0.02 n.d n.d

C01 0.03 n.d 0.08 n.d n.d n.d n.d n.d n.d

R05 0.03 n.d 0.25 n.d n.d 0.06 0.02 n.d n.d

S01 0.13 n.d 0.02 n.d n.d 0.11 0.04 n.d n.d

C24 0.52 0.19 0.39 n.d 0.06 0.36 0.02 n.d n.d

S03 0.03 0.06 0.22 n.d 0.01 0.22 0.05 n.d n.d

C22 0.18 0.05 0.08 n.d n.d n.d 0.01 n.d n.d

S11 n.d n.d 0.18 n.d n.d n.d n.d n.d n.d

C21 0.11 0.27 0.42 n.d n.d 0.16 0.03 n.d n.d

R08 0.05 0.02 0.25 n.d 0.19 0.19 0.04 0.01 n.d

R09 0.04 n.d 0.10 n.d 0.12 0.17 0.02 n.d n.d

P23 0.04 n.d 0.04 n.d n.d n.d 0.01 n.d n.d

E21 0.02 0.01 0.05 n.d n.d n.d 0.01 n.d n.d

R11 0.02 0.03 0.30 n.d 0.04 n.d 0.10 0.14 n.d

R16 0.04 n.d 0.05 n.d n.d n.d n.d n.d n.d

ICE03 0.03 n.d 0.11 n.d 0.10 n.d 0.01 n.d n.d

E24 0.03 n.d 0.03 n.d n.d n.d n.d n.d n.d

P11 0.03 n.d 0.12 n.d 0.06 0.01 0.01 n.d n.d

R14 0.03 n.d 0.07 n.d 0.01 n.d 0.02 n.d n.d

n.d: Not detected (under LOD)

Table S9. PFAS levels in sediment from different regions

Region Number of PFAS Level (ng/g) Reference

Bering Sea (n=6) 8 0.07-1.7 This study

Chukchi Sea 8 0.09-1.53 This study

Eastern Plain Region

(n=29)

12 0.57-5.79

Mongolia-Xinjiang Plateau

(n=5)

12 0.20-0.45 (Qi, et al. 2016)

Qinghai-Tibet Plateau

(n=4)

12 0.29-0.46 (Qi, et al. 2016)

Yunnan-Guizhou Plateau

(n=8)

12 0.09-0.58 (Qi, et al. 2016)

Northeast China Region

(n=4)

12 0.36-0.68 (Qi, et al. 2016)

Four remote Arctic lakes 19 0.19-2.7 (Lescord et al. 2015)

Bohai Sea 9 0.06-2.49 (Gao et al. 2014)

Yellow sea 9 LOD-2.76 (Gao et al. 2014)

East China Sea 9 0.03-1.77 (Gao et al. 2014)

Bohai 19 0.33-2.78 (Chen et al. 2016)

Semi-enclosed Bays of

Korea

9 0.01-0.82 (Shen et al. 2018)

East China Sea 17 0.41-3.06 (Wang et al. 2017)

Sydney Harbour 13 3.52±3.2 (Thompson et al. 2011)

German Bight, German 16 0.056-7.4 (Zhao et al. 2015)

Table S10. Pearson correlation of PFAS levels with basic sediment parameters

Parameters PFBS PFHxS PFOA PFNA PFOS PFDA

Water content -0.22 -0.04 0.21 -0.07 0.14 0.37*

BC 0.03 -0.06 -0.16 0.04 -0.15 0.18

TOC 0.28 0.31 -0.1 0.12 0.26 -0.01

Clay -0.28 -0.21 0.06 -0.41* -0.29 -0.07

Silt 0.02 -0.08 0.11 0.17 0.32 0.09

Fine Sand 0.19 -0.07 -0.18 0.07 0.02 -0.13

Corse sand 0.17 0.17 -0.04 0.05 -0.1 -0.02

δ13C 0.18 0.31 0.15 -0.21 0.13 0.17

C/N 0.54** 0.32 0.17 0.32 0.41 0.09

PFBS 1 0.22 -0.12 0.01 0.57** 0.45**

PFHxS 1 0.10 0.16 0.50** 0.15

PFOA 1 0.12 0.19 0.17

PFNA 1 0.28 0.18

PFOS 1 0.52**

PFDA 1

*Significant at p<0.05, **significant at p<0.01

Table S11. Concentrations of PFASs in the sediment core S03 (ng/g dw)

Depth (m) Year PFBS PFHxS PFOS PFHpA PFOA PFNA PFDA PFUnA FDoA

1 2014.75 0.03 0.06 0.22 n.d 0.01 0.22 0.05 0.01 n.d

2 2011.84 0.20 0.12 0.51 n.d 0.18 0.45 0.18 0.02 n.d

3 2008.59 0.29 0.07 0.57 n.d 0.01 0.32 0.18 n.d n.d

4 2004.45 0.55 0.00 0.59 n.d n.d 0.09 0.14 n.d n.d

5 2000.09 0.07 0.19 0.97 n.d 0.12 0.33 0.00 n.d n.d

6 1995.68 0.13 0.39 0.66 n.d n.d 0.21 0.10 n.d n.d

7 1990.62 0.18 n.d 0.59 n.d 0.02 0.23 0.08 n.d n.d

8 1985.10 0.39 0.03 0.53 n.d 0.01 0.14 0.06 n.d n.d

9 1979.49 0.05 0.04 0.51 n.d 0.18 0.15 0.07 n.d n.d

10 1975.71 0.70 0.21 0.85 n.d 0.00 0.10 0.07 n.d n.d

11 1971.52 0.00 0.15 0.51 n.d 0.13 n.d 0.08 n.d n.d

12 1965.52 0.22 n.d 0.51 n.d n.d 0.06 0.04 n.d n.d

13 1960.48 0.33 n.d 0.38 n.d n.d n.d 0.03 n.d n.d

14 1956.52 0.20 0.30 0.45 n.d 0.15 n.d n.d n.d n.d

15 1952.45 n.d n.d 0.49 n.d 0.06 n.d 0.10 n.d n.d

n.d: Not detected (below LOD)

Table S12. Factor Profiles (% of species sum) from PMF model

Factor 1

(Oceanic transport)

Factor 2

(Atmospheric deposition )

Factor 3

(Terrestrial inputs)

PFBS 0 9 91

PFHxS 61 6 33

PFOA 45 52 3

PFNA 90 0 10

PFOS 6 70 24

PFDA 12 88 0

Fig. S1. PCA and HCA results of PFASs in sediments of the western Arctic and

Bering Sea.

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