Temporal Trends and Geographical Differences of ... - ACS Publications

Subscriber access provided by CORNELL UNIVERSITY LIBRARY

Article

Temporal trends and geographical differences of perfluoroalkyl acids in Baltic Sea herring and white-tailed sea eagle eggs in Sweden Suzanne Faxneld, Urs Berger, Björn Helander, Sara Danielsson, Anna Aroha Miller, Elisabeth Nyberg, Jan-Olov Persson, and Anders Bignert Environ. Sci. Technol., Just Accepted Manuscript • DOI: 10.1021/acs.est.6b03230 • Publication Date (Web): 24 Oct 2016 Downloaded from http://pubs.acs.org on October 24, 2016

Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a free service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are accessible to all readers and citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers

Environmental Science & Technology is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.

Subscriber access provided by CORNELL UNIVERSITY LIBRARY

and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.

Environmental Science & Technology is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.

Page 1 of 32

Environmental Science & Technology

(3, A)

(4, B, C)

(1)

(2)

ACS Paragon Plus Environment


1

Temporal trends and geographical differences of

2

perfluoroalkyl acids in Baltic Sea herring and

3

white-tailed sea eagle eggs in Sweden

Page 2 of 32

4 5

Suzanne Faxneld1*, Urs Berger2†, Björn Helander1, Sara Danielsson1, Aroha Miller1,

6

Elisabeth Nyberg1, Jan-Olov Persson3, Anders Bignert1

7 8

1

9

History, Box 50007, SE-104 05, Stockholm, Sweden.

Department of Environmental Research and Monitoring, Swedish Museum of Natural

10

2

11

Stockholm, Sweden.

12

3

13

* corresponding author: e-mail: [email protected], phone: + 46 (0) 8 5195 4114

Department of Applied Environmental Science, Stockholm University, SE-106 91,

Department of Mathematics, Stockholm University, SE-106 91, Stockholm, Sweden.

14 15 16

ABSTRACT

17

Temporal and spatial trends of perfluoroalkyl acids (PFAAs) were investigated in Baltic Sea

18

herring liver (Clupea harengus) from three sites, and white-tailed sea eagle (WTSE) eggs

19

(Haliaeetus albicilla) from two freshwater and two marine areas in Sweden. Trends of most

20

quantifiable PFAAs increased over the monitored period (1980 – 2014 in herring,

21

1960s/1980s – 2010 in WTSE). No significant decreasing trends were observed for the most

22

recent ten years for any substances, except perfluorooctane sulfonamide (FOSA).

23

Concentrations of perfluorooctane sulfonic acids (PFOS) in herring showed a distinct

1 ACS Paragon Plus Environment

Page 3 of 32


24

decreasing trend moving from the more southern site towards the more northern site,

25

indicating main input of PFOS into the southern Baltic Sea. For WTSE, PFOS concentration

26

was higher in the marine compared to the freshwater environment, explained by the

27

cumulative historic contamination of the Baltic Sea. Similarly, concentrations in WTSE were

28

lower in the northern part of the Baltic Sea compared to further south. Concentrations of

29

PFUnDA, representing long-chain perfluoroalkyl carboxylic acids (PFCAs), showed a more

30

homogenous spatial distribution compared to PFOS for both herring and WTSE, indicating

31

that atmospheric inputs (via precursors) of the long-chain PFCAs are important contributors

32

in the study areas.

33 34

INTRODUCTION

35

Perfluoroalkyl acids (PFAAs) are a group of anthropogenic surfactants comprising a fully

36

fluorinated, hydrophobic alkyl chain typically consisting of 4 to 18 carbon atoms and a

37

hydrophilic functional group.1, 2 The two most well-known PFAAs are perfluorooctanoic acid

38

(PFOA) and perfluorooctane sulfonic acid (PFOS), both of which contain an eight carbon

39

atom backbone. PFAAs possess exceptional stability and surface tension-lowering ability1,

40

rendering them suitable for usage in many applications both industrially (e.g., production of

41

fluoropolymers) and in consumer products (e.g., water and stain proofing agents, fire-fighting

42

foams).1 Moreover, their stability makes them virtually non-degradable, hence

43

environmentally persistent.3 PFAAs have been produced since the early 1950s. In 2000, 3M, the main

44 45

company producing PFOS, voluntarily phased out PFOS, PFOA, and related chemicals.4

46

However, PFOS is still produced in Southeast Asia5, specifically in China.6 In 2009, PFOS

47

and related products were added to annex B (new persistent organic pollutants) of the

48

Stockholm Convention on Persistent Organic Pollutants, resulting in production and usage

49

restrictions.7 2 ACS Paragon Plus Environment


Page 4 of 32

Today, PFAAs are ubiquitous environmental contaminants8 found in water9,

50 51

sediment10, biota11, 12, and humans.13 Long-chain PFAAs bioaccumulate in marine food

52

chains14, with highest concentrations found in organisms at higher trophic levels e.g., marine

53

mammals and predatory birds.11, 15, 8, 16 In contrast to lipophilic contaminants such as dioxins,

54

DDT, and PCBs, PFAAs bind to proteins17; hence highest concentrations are usually found in

55

protein-rich tissues such as liver, serum, and egg yolk.18 Herring (Clupea harengus) is a pelagic species that feeds mainly on

56 57

zooplankton. They are important for human consumption and as prey for marine predators,

58

including white-tailed sea eagles (WTSE) (Haliaeetus albicilla) that feed primarily on species

59

that prey on herring (e.g., pike, Esox Lucius, gulls, Laridae spp., and mergansers, Mergus

60

spp.). WTSE are large birds of prey. In the mid-1960s, they became critically

61 62

endangered in the Baltic due to PCB and DDT exposure.19, 20 After these compounds were

63

banned in the 1970s, populations slowly recovered. Currently, the WTSE population in

64

Sweden is approximately 700 pairs. While the majority of WTSE populations feed primarily

65

on fish and aquatic birds, some northern Lapland populations prey on large mammals such as

66

reindeer (Rangifer tarandus) carcasses during the ice-free period, and herbivores and seals

67

during winter. 45 In its position as apex predator, WTSE remain highly exposed to persistent

68

environmental contaminants. In Sweden, increasing concentrations of PFAAs have been

69

observed in common guillemot (Uria aalge) and peregrine falcon (Falco peregrinus) eggs21,

70

22

71

, grey seals (Halichoerus grypus)23, and otters (Lutra lutra).24 Here we examined temporal and spatial trends of PFAAs in Baltic Sea herring

72

and WTSE from Sweden. Trends are used to draw conclusions on emission histories and input

73

pathways of the different target analytes into the study areas.

74


Page 5 of 32

75


MATERIALS AND METHODS

76 77

Sampling and sample preparation

78 79

Herring

80

Herring samples are collected annually from 17 sites along the Swedish coast within the

81

Swedish National Monitoring Programme for Contaminants in Marine Biota.25 Sampling

82

locations are regarded as reference sites, i.e. far from known pollution sources and ferry

83

routes. Individual herring are stored at -25oC in the Environmental Specimen Bank (ESB) at

84

the Swedish Museum of Natural History (SMNH). Fish sampling was conducted between

85

1980 and 2014 during the months of September to November. Collected specimens were

86

placed individually in polyethylene bags, frozen, and transported to the laboratory for

87

preparation.

88

For this study, three sites were chosen – Gulf of Bothnia (Ängskärsklubb),

89

northern Baltic Proper (Landsort), and southern Baltic Proper (Utlängan) (Figure 1) – because

90

herring from there was the oldest archived in the ESB. Samples stored in the ESB were used

91

for retrospective analysis of PFAA concentrations. Total body weight, liver weight, total

92

length, and gonad maturity were recorded. Herring age was determined via scales.51 Females

93

between 2 and 5 years of age and between 17 to 20 cm length were analysed. For the earlier

94

years (1980-2006), one pool of 12 individual liver samples was used for every other year and

95

site; from 2007 until 2014, two pools containing 12 individual liver samples per pool from

96

each site and year were analysed (see Table S5 for details about years analysed).

97 98

White-tailed sea eagles



99

Page 6 of 32

Annual surveys of WTSE reproduction have been conducted in Sweden since the mid-

100

1960s26, involving collection of addled/dead eggs for examination. We included 83 single

101

eggs from different clutches from 1966 until 2010 from four regions (Figure 1); (1) 18 eggs

102

from 18 sites in northern Inland (Lapland); (2) 14 eggs from 13 southern Inland sites in

103

central Sweden; (3) 30 eggs from 15 sites in the Gulf of Bothnia; and (4) 21 eggs from 17

104

sites in the Baltic Proper. In total, 18 sites are represented by more than one clutch during the

105

study period with time spans from 1 to 40 years (mean 21 years) (see Table S6 for details

106

about years analysed). Each egg was stored in a polyethylene bag inside a box/beaker for

107

transport to the laboratory at the SMNH. Egg contents were homogenized and stored

108

individually at -80o C in the ESB at the SMNH. Individual samples were taken for analysis of

109

PFAAs.

110

WTSE eggs were collected 1 to 2 months after failure to hatch, and were in

111

varying states of desiccation. Corrected wet weight data for PFAAs were calculated by

112

multiplying the measured concentration in the homogenized sample with a desiccation index

113

value based on the sampling weight of the individual egg, related to its interior volume20, and

114

by multiplying with a factor of 1.1 to roughly compensate for the air sac within the egg.

115 116


Page 7 of 32


f fo ul G

A

Ba

B

lti c

Pr

op er

3

ia hn t Bo

1 Inland north Lapland (Lap)

2 Inland central and southern regions (Inl) 3

South Bothnian Sea (sBS)

4

Baltic Proper (BP)

C 117 118

Figure 1. Map of sampling areas. 1-4 are white-tailed sea eagle sites. 1=northern Inland (Lapland), 2=southern

119

Inland, 3=Gulf of Bothnia, 4= Baltic Proper. A-C represent herring sites; A= Ängskärsklubb (Gulf of Bothnia),

120

B= Landsort, C= Utlängan (both in the Baltic Proper).

121 122

Analytical methods

123

Abbreviations of PFAAs (see supplementary information) are according to Buck et al.2 The

124

target analytes in this study were PFBS, PFHxS, PFOS, PFDS, FOSA, PFHxA, PFHpA,

125

PFOA, PFNA, PFDA, PFUnDA, PFDoDA, PFTrDA, PFTeDA, and PFPeDA. FOSA was the

126

only precursor compound included here and will, for simplicity, be included under the generic

127

term PFAAs. The sample extraction procedure used has been described previously.27 Briefly,

128

a sample aliquot of approximately 1.0 g (herring liver) or 0.5 g (WTSE egg) homogenized

129

tissue in a polypropylene (PP) centrifuge tube was spiked with 1.0 ng (herring) or 10 ng 6 ACS Paragon Plus Environment


Page 8 of 32

130

(WTSE) each of a suite of mass-labelled internal standards (18O- or 13C-labelled

131

perfluoroalkane sulfonic acids [PFSAs] and perfluoroalkylcarboxylic acids [PFCAs]).

132

Samples were extracted twice with 5 mL of acetonitrile in an ultrasonic bath. Following

133

centrifugation, the supernatant extract was removed and the combined acetonitrile phases

134

were concentrated to 1 mL under a stream of nitrogen. The concentrated extract underwent

135

dispersive clean-up on graphitised carbon and acetic acid. A volume of 0.5 mL of the purified

136

extract was added to 0.5 mL of aqueous ammonium acetate. Precipitation occurred and the

137

extract was centrifuged before the clear supernatant was transferred to an autoinjector vial for

138

instrumental analysis, and volume standards 13C8-PFOA and 13C8-PFOS were added.

139

Aliquots of the final extracts were injected automatically on an ultra-performance liquid

140

chromatography (UPLC) system (Acquity, Waters) coupled to a tandem mass spectrometer

141

(MS-MS; Xevo TQS, Waters). Instrumental analysis and quantification was performed

142

according to Vestergren et al.28 In short, compound separation was achieved on a BEH C18

143

UPLC column (1.7 µm particles, 50× 2.1 mm, Waters) with a binary gradient of ammonium

144

acetate buffered methanol and water. The MS-MS was operated in negative electrospray

145

ionisation mode. Quantification was performed in selected reaction monitoring

146

chromatograms using the internal standard method. All results are given on a sample wet

147

weight (ww) basis. Quantified concentrations for PFAAs in WTSE eggs were corrected for

148

the respective egg’s desiccation (see above) before statistical analysis.

149 150

Quality control

151

The extraction method used here (with the exception of the concentration step) has previously

152

been validated for biological matrices and showed excellent analyte recoveries ranging

153

between 90 and 110% for PFCAs from C6 to C14.29 Including extract concentration, we

154

determined recoveries between 70 − 90% for C6- to C10-PFCAs and 65 − 70% for C11-C15


Page 9 of 32


155

PFCAs. Extraction efficiencies for PFSAs, including FOSA, were determined to be 70 − 95%.

156

Method quantification limits (MQLs) for all analytes were determined on the basis of blank

157

extraction experiments and ranged between 0.01 and 0.3 ng/g ww. Fish tissue sample used in

158

an international inter-laboratory comparison (ILC) study in 200730 was analysed as a control

159

along with all sample batches. The concentrations obtained were in good agreement with

160

mean concentrations from the ILC study for all seven compounds quantified in the ILC.

161 162

Statistical analysis

163

Values below Method Quantification Limits (MQL) were replaced by MQL divided by the

164

square root of 2 prior to all statistical analyses. Power analyses were carried out to estimate

165

the lowest detectable trend for a monitoring period of 10 years at a fixed power of 80%, given

166

the current residual variance from a log-linear regression analysis. In the same way, the

167

number of years required to detect an annual trend of 10% were estimated for the various data

168

sets. The significance level (α) for all statistical tests was 5%. Data were log transformed

169

before analysis, and yearly geometric means were calculated (Table S5, S6). We used

170

statistical software PIA52 for trend analyses.

171

ΣPFSA was calculated and included the detected PFSAs - PFHxS and PFOS for

172

herring and PFHxS, PFOS, and PFDS for WTSE. ΣPFCA was calculated. For both species it

173

included PFOA, PFNA, PFDA, PFUnDA, PFDoDA, and PFTrDA, and for WTSE also

174

PFTeDA and PFPeDA. To study changes in homologue pattern between different sampling

175

periods and species, Principal Component Analysis (PCA) was performed on the proportions

176

of a set of individual PFAAs relative to the sum of this set, and log-transformed prior to PCA

177

analysis. Before the PCA-scores were plotted they were centered and scaled to 100%. The

178

PCA loadings were overlaid as a biplot and Hotellings 95% confidence ellipses for the center

179

of gravity for each site plotted. We conducted a Hotellings T-square test to detect possible



180

significant differences in homologue pattern (multivariate means) between the different

181

sampling periods. Because three to four time-periods were tested against each other, p-values

182

were compared using a Bonferroni adjusted significance level of 0.0167. Tests were carried

183

out using PIA.52

184

Page 10 of 32

We performed a log-linear regression for the temporal trend analysis for the

185

entire investigated period and the most recent 10 years using yearly geometric mean values.

186

To achieve a fairly stable estimate of the recent concentrations, a geometric mean of the last 3

187

years was calculated. A simple 3-point running mean smoother was fitted to the annual

188

geometric mean values. Additionally, non-linearity of trends was investigated using a

189

Change-Point detection method suggested by Sturludottir et al.31 This method iteratively

190

searches for a combination of two log-linear regression lines that explains significantly more

191

of the total variance than that explained by a single regression line for the whole study period.

192

In order to combine temporal trends at various contaminant levels in the same graphs, data

193

were transformed to percent of maximum concentration prior to change-point detection

194

analysis, whereas the tables (S1, S2) contains the log-transformed values, expressed as

195

geometric mean.

196

In order to investigate spatial trends of PFAA in herring and WTSE, Stata13

197

was used. PFOS and PFUnDA were investigated as representative of long-chain PFSAs and

198

PFCAs, respectively, because they showed the highest detection frequencies in the analysed

199

samples. For PFOS, we investigated the period 1980 to 2000 because phase-out of PFSAs by

200

3M began in 2000, which significantly affected subsequent trends. For PFUnDA, 1980 to

201

2010 was used, because samples from this period were available for almost all sampling sites

202

for both species. If the slopes of the time trends of PFAA concentrations between the

203

sampling sites for a given species did not differ significantly, spatial differences in PFAA

204

concentrations were investigated. This was done using estimated concentration values from


Page 11 of 32


205

the time trend regression for PFOS and for PFUnDA in 1990 and 1995, respectively (middle

206

of the respective period). For WTSE spatial analyses, the Gulf of Bothnia and the Baltic

207

Proper were grouped as marine areas, while the southern and northern inland areas were

208

grouped as freshwater areas.

209 210 211

RESULTS AND DISCUSSION

212

Henceforth, PFOS and PFUnDA are used as examples of PFSA and PFCA, respectively,

213

because PFOS had the highest concentrations and has now been phased out, and because

214

PFUnDA concentrations were uniformly detected in both herring and WTSE. Detailed results

215

for all compounds are included in the supplementary data.

216

For herring, 9 of 15 analysed PFAA were detected in most samples from all

217

three sites. PFBS, PFDS, PFHxA, PFHpA, PFTeDA, and PFPeDA were below MQL in >

218

50% of investigated years, and were thus not included in the statistical analysis. In WTSE

219

eggs, 12 of 15 investigated PFAA were detected; however, PFOA was infrequently detected

220

in samples from the two inland areas. PFBS, PFHxA, and PFHpA were generally below MQL

221

and were thus excluded from statistical analysis.

222 223

Concentrations and contaminant profiles

224

PFOS is typically the dominant PFSA in wildlife.12 Here, PFOS was the dominant compound

225

in both herring and WTSE at all sites and in all years (Figure S1-S7). In herring, PFOS

226

percentage increased over time, constituting 80-90% of ΣPFSA in the 1980s to 1990s, to

227

around 95% post-1990s. In WTSE, PFOS was more stable throughout the examined time

228

period, constituting approximately 98% of ΣPFSA.

229 230

In herring, PFOS concentrations in the most recent year i.e., 2014, were similar at the two Baltic Proper sites i.e., Landsort and Utlängan (13-14 ng/g ww, sites B and C, 10 ACS Paragon Plus Environment


Page 12 of 32

231

Figure 1), while concentrations were half that at Ängskärsklubb, in the Gulf of Bothnia (site

232

A, Figure 1) (Table S1). In WTSE, concentrations of PFOS in 2010 were similar in the Gulf

233

of Bothnia and the southern inland samples, while concentrations in the Baltic Proper were

234

twice as high. By contrast, northern Inland had concentrations three times lower compared to

235

the Gulf of Bothnia and the southern Inland site (Table S2).

236

For ƩPFCA, PFOA, PFNA, and PFUnDA were dominant in herring,

237

contributing 20-22%, 28-30%, and 19-22%, respectively (Figure S1-S3), consistent with

238

results from slimy sculpin (Cottus cognatus) in Lake Ontario, where PFOA and PFUnDA

239

were also the dominant PFCAs.32 In skipjack tuna (Katsuwonus pelamis) from the mid-north

240

Pacific and Indian Oceans, PFUnDA was the dominant PFCA, while PFOA was detected in

241

only a few samples.46 In WTSE, the dominant PFCAs were PFNA, PFUnDA, and PFTrDA,

242

constituting 20-23%, 24-28% and 18-30% of ƩPFCA, respectively (Figure S4-S7). Likewise,

243

PFUnDA and PFTrDA were the dominant PFCAs in peregrine falcon eggs22, Baltic common

244

guillemot eggs33 in Sweden, and in ancient murrelet (Synthliboramphus antiquus), Leach’s

245

storm-petrel (Oceanodroma herodias), and rhinoceros auklets (Cerorhinca monocerata) from

246

the western Pacific coast of Canada.34 Moreover, in double-crested cormorants

247

(Phalacrocorax auritus) and great blue herons (Ardea herodias), two coastal bird species,

248

PFNA was the dominant PFCA.34 The relative amount of PFOA was much lower in WTSE

249

compared to herring, constituting only about 1.5-3%. Such large differences in PFOA

250

contribution to ƩPFCA between predatory bird and prey fish has been described earlier,47 and

251

could be due to differences in bioaccumulation factors based on differences in toxicokinetics,

252

especially elimination half-lives, or due to precursor degradation along the food chain.47

253

PFOA percentage of ƩPFCA decreased over time in WTSE from all areas over

254

the entire time period (i.e. 1960s/1980s to 2010) and also in herring from the Gulf of Bothnia

255

(1980 to 2014). For PFUnDA, increases over the entire time period were seen in herring from


Page 13 of 32


256

the Gulf of Bothnia and northern Baltic Proper, and in WTSE from the Baltic Proper and

257

northern Inland. In herring, PFUnDA constituted 12-15% in the 1980s, increasing to 20-25%

258

in the 2000s. In WTSE from the Baltic Proper, PFUnDA constituted 5-15% in the 1970s,

259

increasing to approximately 20% in the 2000s. PFTeDA, PFPeDA, and PFDS were found

260

only in WTSE samples (Tables S5, S6). In melon-headed whales (Peponocephala electra)

261

from Japan, the concentration of PFUnDA increased greatly from 1982 to 2006.48 In contrast,

262

in northern sea otters (Enhydra lutris kenyoni) from Alaska, PFUnDA was rarely detected and

263

only found in low concentrations, while PFNA was the dominant PFCA, increasing from

264

1992 to 2007.49

265

In WTSE, concentrations of odd chain PFCAs (PFNA [C9], PFUnDA [C11], and

266

PFTrDA [C13]) were much higher compared to their adjacent even chain PFCAs (Table S2), a

267

pattern not seen in herring. Similarly, this pattern of higher concentrations of long-chained

268

odd numbered PFCAs has been reported in various species e.g., rhinoceros auklet, Leach’s

269

storm petrels, and ancient murrelet34, beluga whales (Delphinapterus leucas) from Alaska,

270

herring gull eggs from Norway, and seabird eggs from the Canadian Arctic.35, 36, 37 Moreover,

271

in otters this pattern was more pronounced for marine compared to freshwater samples.24

272

Such a pattern in biota indicates a significant contribution of PFCAs originating from

273

atmospheric transformation of precursor compounds.38 However, this process alone could not

274

explain the difference in patterns observed between the freshwater and marine WTSE samples

275

in this current study. The marine and freshwater environments of Sweden represent different

276

emission histories (cumulative historic or snapshot in time, respectively22), which will also

277

have an influence on the detected pattern, as discussed below.

278

A clear change in the relative concentration of the PFAAs over time in herring

279

was observed (Figure 2a). PFHxS and FOSA dominated in the earlier years (1983-1999),

280

while between 2000-2009 and 2010-2014 the relative concentrations of some of the



Page 14 of 32

281

carboxylic acids, PFNA, PFUnDA, and PFTrDA, increased. There were also some significant

282

differences between the three herring sites. For 1983-1999, the relative concentration of

283

FOSA was higher in the Gulf of Bothnia, while in the southern Baltic Proper, the relative

284

concentration of PFOS was higher. In 2010-2014, the relative concentration of PFUnDA was

285

higher in the Gulf of Bothnia compared to the southern and northern Baltic Proper. No

286

significant differences between sites were seen in 2000-2009. For WTSE, there were

287

significant differences in relative concentration of PFAAs between the different time periods,

288

except 1980-1989 and 1990-1999 (Figure 2b). Earlier years were dominated by PFOS and

289

PFHxS while in the later years, relative concentrations of the carboxylic acids PFNA,

290

PFUnDA, and PFTrDA, showed increased relative concentrations. In addition, for the later

291

time period, i.e. 2000-2010, the relative concentrations of PFHxS and FOSA were lower in

292

the southern Inland area compared to the other three WTSE areas. A comparison of the

293

PFAAs pattern in herring and the Baltic Sea WTSE (i.e. Gulf of Bothnia and Baltic Proper

294

areas) in 1980-2010 showed significant differences (Figure 2c). Relative concentrations of

295

PFOS and PFTrDA were higher in WTSE, whereas the relative concentrations of PFHxS,

296

FOSA, and PFNA were higher in herring.

297 298

a)


Page 15 of 32


299 300 301

b)

302 303 304 305

c)



Page 16 of 32

306 307

Figure 2. Principal component analysis, biplot, and Hotelling’s 95 % confidence ellipses for centers of gravity

308

for each group. Changes over time in relative abundance of PFOS, PFHxS, FOSA, PFNA, PFUnDA, and

309

PFTrDA in a) herring at three different sites, Gulf of Bothnia (GB), northern Baltic Proper (nBP), and southern

310

Baltic Proper (sBP) and divided into three time periods, 1983-1999, 2000-2009, and 2010-2014 b) WTSE at four

311

different areas, Gulf of Bothnia (GB), Baltic Proper (BP), southern Inland (SI), and northern Inland (NI) and

312

divided into four time periods, 1966-1979, 1980-1989, 1990-1999, and 2000-2010 c) differences in PFAAs

313

pattern between herring and Baltic Sea WTSE in 1980-2010.

314 315

Temporal trends of PFSAs

316

Generally, increasing trends of PFSA compounds over the whole time period were seen for

317

both herring and WTSE, but not at all sites/areas. FOSA showed decreasing concentrations at

318

some herring sites (Table 1, Figure 3, Tables S1-S2, Figures S8, S9).

319 320

Table 1. Concentration trends (average annual percentage change) for PFOS and PFUnDA (herring liver and

321

WTSE eggs) assessed from annual geometric mean values.

Herring

Compound

Site name

Ntot

PFOS

s. Baltic Proper

31

Nyrs

Year

Trend% 95% CI

P

23

1980-2014

4.4 (2.8,6.0)

0.000 +++

10

2005-2014

3.2 (-3.3,10)

0.2991


Page 17 of 32


PFUnDA

WTSE

PFOS

n. Baltic Proper

31

Gulf of Bothnia

31

s. Baltic Proper

31

n. Baltic Proper

31

Gulf of Bothnia

31

Baltic Proper

21

Gulf of Bothnia

southern Inland

northern Inland

PFUnDA

30

14

18

Baltic Proper

21

Gulf of Bothnia

30

southern Inland

14

northern Inland

18

23

1980-2014

7.3 (5.3,9.2)

0.000 +++

10

2005-2014

3.9 (-3.6,12)

0.2752

23

1980-2014

5.9 (3.9,7.9)

0.000 +++

10

2005-2014

-.16 (-10,11)

0.9239

23

1980-2014

7.3 (5.4,9.1)

0.000 +++

10

2005-2014

-5.2 (-14,4.0)

0.2206

23

1980-2014

8.6 (6.9,10)

0.000 +++

10

2005-2014

-2.9 (-8.7,3.2)

0.3009

23

1980-2014

8.5 (6.4,11)

0.000 +++

10

2005-2014

-4.6 (-16,8.0)

0.4125

15

1966-2010

6.9 (4.2,9.7)

0.000 +++

6

2001-2010

-2.5 (-12,7.6)

0.520

24

1969-2010

7.2 (4.5,9.9)

0.000 +++

8

2001-2010

-7 (-28,20)

0.513

11

1986-2010

1.5 (-5.5,9.1)

0.644

5

2002-2010

-3.6 (-30,32)

0.727

14

1966-2009

.89 (-2.8,4.7)

0.618

6

2001-2009

-8.3 (-39,38)

0.587

15

1966-2010

15 (12,19)

0.000 +++

6

2001-2010

4.8 (-10,22)

0.448

24

1969-2010

13 (10,16)

0.000 +++

8

2001-2010

-7.1(-24,13)

0.396

11

1986-2010

6.3(.98,12)

0.024 +

5

2002-2010

-3.9(-27,27)

0.678

14

1966-2009

12(9.6,14)

0.000 +++

6

2001-2009

8.4(-3.4,22)

0.122

322

The total number of samples for the whole time period (Ntot) and number of years (Nyrs) for the various time-

323

series are given. A second line at each site presents the results for the last 10 years period. P shows the p-value of

324

the trend. A + after the p-value indicates a positive trend; + p

Temporal Trends and Geographical Differences of ... - ACS Publications

Recommend Documents