Pine Needles for the Screening of Perfluorinated Alkylated

Subscriber access provided by CORNELL UNIVERSITY LIBRARY

Article

Pine needles for screening of Perfluorinated Alkylated Substances (PFASs) along ski tracks Mária Chrope#ová, Pavlína Karásková, Roland Kallenborn, Eva Klemmová Gregušková, and Pavel #upr Environ. Sci. Technol., Just Accepted Manuscript • DOI: 10.1021/acs.est.6b02264 • Publication Date (Web): 26 Jul 2016 Downloaded from http://pubs.acs.org on July 28, 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 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 21

Environmental Science & Technology

1

Pine needles for screening of Perfluorinated Alkylated Substances (PFASs) along ski tracks

2 3 4

Mária Chropeňová1, Pavlína Karásková1, Roland Kallenborn2, Eva Klemmová Gregušková1, Pavel Čupr1*

5 6 7 8 9

1

Research Centre for Toxic Compounds in the Environment (RECETOX), Masaryk University, Kamenice 753/5, pavilion A29, 625 00 Brno, Czech Republic 2 Norwegian University of Life Sciences (NMBU), Department of Chemistry, Biotechnology and Food Science (IKBM), P.O. Box 5003, Christian M. Falsens veg 1, NO-1432 Ås, Norway

10 11 12 13 14 15 16 17 18 19

*Corresponding author: Pavel Čupr; [email protected]; +420 549 493 511, Research Centre for Toxic Compounds in the Environment (RECETOX), Masaryk University, Kamenice 753/5, pavilion A29, 625 00 Brno, Czech Republic

Mária Chropeňová: [email protected], +420 549 491 462 Pavlína Karásková: [email protected], +420 549 495 639 Roland Kallenborn: [email protected], +47 67232497 Eva Klemmová Gregušková: [email protected], +421 949 890 784

1 ACS Paragon Plus Environment


20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36

Abstract Perfluorinated alkylated substances (PFASs) are today considered as persistent, toxic and bioaccumulative contaminants. PFOS and PFOA are currently listed as priority substances under the UNEP global convention for the regulation of POPs. A previous study reported higher levels of PFASs in pine needles near to ski areas. Their application as stain repellent in modern outdoor clothes and in ski waxes is assumed to be potential source. Pine trees (Pinus mugo in Slovakia, Pinus sylvestris in Norway) were chosen for sampling in ski resorts. Relative distributions, overall concentrations, trend estimates, elevation patterns, and distance from primary sources were assessed. Perfluorooctanoic acid (PFOA) was the predominant PFAS constituent in pine needles from Slovakia (8 – 93%). In Norway, the most abundant PFAS was perfluorobutanoic acid (PFBA: 3 – 66%). A difference in product composition (particularly in ski waxes) and differences in Norwegian and Slovakian regulations are considered to be the primary reason for these differences. Open application of PFOA in industry and products has been banned in Norway since 2011. The replacement of PFOA with short chain substitutes is thus considered the reason for the observed pattern differences in the analysed pine needles. Regular monitoring and screening programs are recommended.

37 38 39

Key words Pine needles, ski areas, PFAS, PFOA, biomonitoring

40 41 42 43

GRAPHICAL ABSTRACT

44


Page 2 of 21

Page 3 of 21

45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85


Introduction Perfluorinated alkylated substances (PFASs) are a group of high-production volume chemicals identified as persistent environmental pollutants in virtually all environmental compartments. PFASs are characterized by a hydrophobic fluorinated carbon tail attached to a polar hydrophilic head.1 The PFAS group consists of perfluorinated sulfonic acids (PFSAs), perfluorinated carboxylic acids (PFCAs), fluorotelomer alcohols (PFTOHs), perfluorinated sulphonamides (FOSAs), sulphonamido ethanols (FOSEs) as well as medium and highmolecular weight fluoropolymers.2 PFASs are characterised by extreme environmental stability. This is mainly caused by the stability of the carbon–fluorine bond. PFASs possess special physical-chemical properties which make them highly attractive in a variety of technical applications. They are highly surface-active and amphiphilic. As such, they are applied as stain repellents, surface coatings and firefighting agents.1 However, selected PFAS are known to bioaccumulate in food webs and are even found in substantial concentrations in humans.3–5 Due to their documented harmful effects on the environment, in 2009 perfluorooctansulfonate (PFOS) was officially added as a persistent organic pollutant (POP) to the priority list (Annex B: restriction of use) of the Stockholm Convention for global regulation of POPs, and perfluorooctanoic acid (PFOA) is currently under consideration.6,7 PFOA is characterised as a highly persistent, bioaccumulative and toxic (PBT) substance.8,9 Consequently, the Persistent Organic Pollutants Review Committee (POPRC) of the UNEP convention for the global regulation of persistent organic pollutants (Stockholm “POPs” convention) confirmed that PFOA meets the official priority criteria (persistence, bioaccumulation, potential for long-range environmental transport, adverse effects) at their last meeting in October 2015 in Rome. A working group is currently preparing a draft risk profile for PFOA.10 This illustrates the international regulative priorities for PFAS-related compounds and for PFOA and PFOS in particular. PFASs have been produced since the 1950s and are used in many industrial and household products.11–13 In addition to the above mentioned application areas, PFASs are also used in ski waxes.14–16 Regardless of pollutant type, the potential environmental risk is usually assessed by long term monitoring of potentially contaminated environments and a subsequent exposure assessment. However, in remote sites (such as ski areas, high mountains habitats) the installation of advanced, power consuming monitoring equipment is not ideal due to limited power supply and logistical constraints (transportation and maintenance of equipment). Thus, for integrated sampling, naturally occurring, potentially accumulating sample material (i.e. suitable vegetation in terrestrial environments for metal surveys, mussels in marine environments for POPs) are often selected.17,18 For organic pollutants, pine needles have also been previously evaluated as passive samples for integrated monitoring purposes.19,20 Based on the positive results of these previous investigations, this study validated pine needles (Pinus species) as suitable sample material 21,22 and integrated passive sampler for the screening of selected PFAS along cross-country and downhill ski tracks in Slovakia and Norway. Due to their wax cuticle, pine needles have strong adsorptive surface properties. The versatility of this sample type has been previously proven for legacy pollutants.23–25 3 ACS Paragon Plus Environment


86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110

However, pine needles had never been applied as a monitoring tool for PFAS release and exposure risks associated with skiing activities. From a logistical perspective, pine needles are ubiquitously available in most ski resort areas, and are easy to collect and store for analytical purposes, as shown by a suit of studies on legacy POPs.22,25–28 A first pilot study conducted in 2014 confirmed the suitability of pine needles for PFAS screening. However, during this preliminary study mountain pine (Pinus mugo) needles were exclusively evaluated in selected Slovakian mountain regions without a direct link to potential local sources.22 The relevance of ski waxes as a potential source of environmental contamination of PFASs has already been confirmed in earlier studies, mainly focussing on occupational aspects.29,30 Fluorinated ski waxes usually contain semifluorinated n-alkanes (SFAs) and perfluorinated compounds.31,32 This usually also includes perfluoroalkyl carboxylic acids (PFCAs). The global production of ski waxes is estimated to be several tonnes per year.14 As an additional source in recreational skiing areas, PFAS may also be released to the environment from outdoor clothing. In addition to direct exposure to PFASs during ski-preparation and recreational activities, PFAS emissions from outdoor clothes are also expected to contribute to the overall exposure of persons engaging in these types of recreational activities during winter.13 Earlier studies showed that PFASs associated with aerosol and atmospheric particles are preferably deposited on the wax surface layer of needles.22 In addition, pine trees are a typical vegetation in skiing areas and thus easily available as sampling material, regardless of location. The selected pine trees (Dwarf mountain pine = Pinus mugo in Slovakia, Scots pine = Pinus sylvestris in Norway) were sampled in close vicinity and inside the ski resort grounds chosen for this study. In addition to PFAS level and distribution, this study examined sampling site-specific criteria, uptake profiles in the two pine species, as well as the annual needle growth characteristics.

111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126

Sampling sites Pine needles from trees in the vicinity of representative skiing locations were collected for quantitative PFAS analysis. The chosen sampling location lay in the direction of prevailing wind from the ski resorts and cross country tracks. For each location, two representative sites were chosen. The Slovakian sampling sites are shown in Figure 1 and the Norwegian sampling sites in Figure 2. In Slovakia: Kopske seddle (Site 10) is a high mountain location in the Belianske Tatra Mountains. This site is characterised by direct atmospheric pollution from nearby local sources, most probably from Polish regions. Zilina (Site 9) is a regional centre with industrial activity and an urban area. However, this area is not expected to significantly influence the skiing sites. The remaining eight sampling sites are located in the Western Carpathians region (Little Fatra – Sites 1, 2, 3, 4, Great Fatra – Site 8 and Tatra Mts. – Sites 5, 6, 7) and are all considered as background locations with respect to PFASs. The sampling of needles from Pinus mugo (Dwarf mountain pine) was conducted from June to July 2014 in Slovakia. This species is considered representative for the high mountains areas in Slovakia. 4 ACS Paragon Plus Environment

Page 4 of 21

Page 5 of 21

127 128 129 130 131 132 133 134 135 136

137 138 139 140 141


In Norway: Ås (municipality in Akershus County) (Site 18) was chosen as a potential contaminated site due to the proximity to the Ås municipality. In addition, as an urban background site (low or minimal PFAS levels expected), the pine trees in the park close to the royal palace in Oslo were sampled as reference. All remaining six sampling sites (Sites 11, 12, 13, 14, 15, 16) were chosen from south-eastern Norwegian ski resorts. Needles of Pinus sylvestris (Scots pine) were sampled in October 2015. This tree is the only native Pinus species in Norway. The geographical coordinates were recorded using Google maps and are shown in the Supporting information (SI) (Tables S1, S2).

Figure 1: Slovakian sampling sites: 1 – Martinske hole Mt. (E); 2 – Martinske hole Mt. (W); 3 – Krivan Mt. (SW); 4 – Krivan Mt. (N); 5 – Chopok Mt.; 6 – Sivy vrch Mt. (SE); 7 – Sivy vrch Mt. (E); 8 – Ostredok Mt.; 9 – Zilina (negative reference site); 10 – Kopske seddle Mt. (positive reference site)



142 143 144 145 146 147

Page 6 of 21

Figure 2: Norwegian sampling sites: 11 – Oslo winter park; 12 – Hafjell ski centre; 13 – Birkebeineren, Lillehammer; 14 – Kongsberg, ski centre; 15 – Holmenkollen, Holmenkollen ski jump; 16 – Holmenkollen, Midtstuen ski jump; 17 – Oslo (negative reference site); 18 – Ås (positive reference site)

148

Analysed compounds All target perfluorinated alkylated substances (PFASs) are shown in Table 1.

149 150

Table 1: Analysed perfluorinated alkylated substances

IUPAC name perfluorobutanoic acid perfluoropentanoic acid perfluorohexanoic acid perfluoroheptanoic acid perfluorooctanoic acid perfluorononanoic acid perfluorodecanoic acid perfluoroundecanoic acid perfluorododecanoic acid perfluorotridecanoic acid perfluorotetradecanoic acid perfluorobutanesulfonic acid perfluorohexane sulfonate perfluoroheptane sulfonate perfluorooctane sulfonate perfluorodecanesulfonic acid

acronym PFBA PFPA PFHxA PFHpA PFOA PFNA PFDA PFUnDA PFDoDA PFTrDA PFTeDA PFBS PFHxS PFHpS PFOS PFDS

151 6 ACS Paragon Plus Environment

CAS number 375-22-4 2706-90-3 307-24-4 375-85-9 335-67-1 375-95-1 335-76-2 2058-94-8 307-55-1 72629-94-8 376-06-7 375-73-5 432-50-7 375-92-8 1763-23-1 39108-34-4

Page 7 of 21

152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192


Material and methods Solvents used for sample preparation and analysis were purchased from Fluka (Buchs, Germany), and were of environmental trace analytical quality. Needles were separated from the branches and sorted by age into one- to five-year-old needles in the case of Pinus mugo and into one- to three-year-old needles in the case of Pinus sylvestris.33 Needles were wrapped in aluminium foil and stored in polyethylene bags in a freezer at -20 °C until further processing. A brief method description is provided here. However, more details on the sampling method can be found in a previous publication.22 Needles were homogenised using an electric grinder (IKA A11 basic, Sigma-Aldrich, Praha, Czech Republic). 100 mL of Milli-Q water (Super-Q Water System, Millipore Corp., Bedford, MA, USA) was added prior to lyophilisation. For lyophilisation, a standard freeze drying unit was used (Scanvac Coolsafe TM, Trigon-plus, Čestlice, Říčany u Prahy, Czech Republic). Preweighed 10 g samples were extracted with an automatic extractor (Büchi B-811, Labortechnik AG, Flawil, Switzerland) in methanol with the addition of ammonium acetate (Fluka Chemie GmbH, Buchs, Germany; 400 mg L-1 methanol). Prior to extraction the following recovery standards were added: 13C8PFOA and 13C8PFOS – 50 µl, 80 ng mL-1. The concentrated methanol extracts for PFAS analysis were diluted with 200 mL HPLC gradient grade water (Fisher Scientific, Loughborough, UK) followed by purification using SPE cartridges (Oasis® Wax 6cc, 500 mg, Waters, Bedford, CA) which were conditioned with 5 mL methanol, 10 mL basic methanol (methanol modified with 4 mL of NH4OH) (ammonia solution 4mL L-1 methanol) and 5 mL HPLC gradient grade water. Diluted extracts were passed through the cartridges at 1 drip per second with a final wash step with wash buffer (ammonium acetate and acetic acid in water). Elution was performed using 6 mL neutral methanol and 8 mL basic methanol. The resulting eluents were collected in polypropylene falcon tubes (Eastport Lifescience, Praha, Czech Republic), concentrated under a gentle stream of nitrogen to almost dryness. Then, 1 mL volume with 0.5 mL MeOH and 0.5 mL 5 mM ammonium acetate in water was added. The re-diluted extracts were finally cleaned through a syringe filter (nylon membrane, 13 mm diameter and 0.45 μm pore size, Labicom Czech Republic) and transferred into HPLC autosampler vials. Eight mass-labelled internal standards (13C2 PFHxA, 13C4 PFOA, 13C5 PFNA, 13C2 PFDA, 13C2 PFUnDA, 13C2 PFDoDA, 18O2 PFHxS, 13C4 PFOS) (Wellington Laboratories Inc., Guelph, Ontario Canada) were added as a final step before HPLC-MS analysis. The separation, identification and quantification of all target PFASs were performed using high performance liquid chromatography with an Agilent 1290 (Agilent Technologies, Palo, Alto, California, USA) connected to a mass spectrometer QTRAP 5500 (ABSciex, Foster City, California, USA). Chromatographic separation was performed at 20 °C on a SYNERGI 4μ Fusion RP 80Å 50 mm x 2 mm column with a corresponding precolumn (SecurityGuard: C18 4x2 mm, Phenomenex, California, USA). The flow rate was set to 200 μL min-1. Mobile phase A was methanol, and mobile phase B was methanol/5 mM ammonium acetate in water 55/45 (v/v). Aliquots of 10 μL were injected into the column and gradient elution was used for PFAS separation. Before the next separation, the column was equilibrated using the 7 ACS Paragon Plus Environment


193 194 195

initial content of the mobile phase for 3 minutes. The mass spectrometer was operated in electrospray negative ionization mode (ESI-) using two MRM transitions for each compound except PFBA, at 450°C and ion voltage 4500 V (SI, Table S3).

196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211

Quality assurance and quality control The efficiency of the extraction method was validated by spiking pine needle homogenates with 50 µl of 80 ng mL-1 mixture of native perfluorinated alkylated substances followed by the extraction method described above.22 Percentage recoveries for all native PFASs are reported in Table S4 (SI). Evaluation and quantification of data was done by internal standard-based calculations using nine-point quadratic calibration curves (r2 > 0.99) ranging from 0.004 to 20 ng mL-1. Internal standards (13C4 PFBA, 13C2 PFHxA, 13C4 PFOA, 13C5 PFNA, 13 C2 PFDA, 13C2 PFUnDA, 13C2 PFDoDA, 18O2 PFHxS, 13C4 PFOS) were added to all samples prior to extraction and the same amount of these standards was added to each calibration point. The reported concentrations are laboratory blank corrected (one blank in each batch of 10 samples). Recoveries of 13C8PFOA in real samples ranged from 65 % to 118 %, with an average value of 95 ± 15 %, and of 13C8PFOS from 56 % to 110 % with an average value of 90 ± 18 %. Method quantification limits (MQLs) in ng g-1 dw were defined as the mean concentration of procedural blanks plus 10× the standard deviation of blank response. All results and MQL values are listed in the SI, Tables S5, S6, S7.

212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233

Results and discussion The primary objective of the study was to establish distribution and concentration information on PFAS residues along representative ski-tracks for evaluation of regulatory measures. High mountain habitats of the Western Carpathian Mountains in Slovakia are densely covered with Pinus mugo (Dwarf mountain pine), which usually has five different year-classes of needle generations on their branches in the Slovakian mountains and is a typical pine tree species at high elevation locations (more than 1000 m a.s.l). In Norway, Pinus sylvestris (Scots pine), the only native pine species, was sampled at lower elevations (max. 512 m a.s.l) than the Slovakian pine needle samples. In Norway on Pinus sylvestris, only three year-classes of needle generations could be collected because of the characteristic lifetime of needles in this area, which differs from the Pinus mugo. In Norway, pine needles were collected at various ski resorts in October 2015. At many sites, the oldest generation (3rd year) of pine needles could not be found at the sample location.34 Therefore, a direct comparison of the age classes could only be done for the first and second generation needles. For this reason, second generation needles were used for comparing all sites in this study. At selected sites, additional comparison was done of three year-classes of needle generations for Pinus sylvestris and five year-classes of needle generations for Pinus mugo. Because sampling of needles used different tree species and was also conducted in different countries (Pinus mugo – Slovakia, Pinus sylvestris – Norway), these potential differences must be taken into account. The plant characteristic physiology might restrict the comparability of the here provided results. However, since PFASs are reported as highly 8 ACS Paragon Plus Environment

Page 8 of 21

Page 9 of 21

234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257


persistent, surface active and amphiphilic chemical pollutants 35, it was not expected significant alteration of distribution patterns due to chemical transformation for PFASs on pine needles. Therefore, the usage of different pine species (predominant in the respective countries) is considered as appropriate for performed comparison. The morphology of the needles of each species (e.g. specific leaf area and surface) may have a crucial role in the distribution of pollutants.36,37 Needles of Pinus mugo are densely set on the branches, 3-8 cm long, 1.5-2.2 mm wide, and dark or light green. Needles of Pinus sylvestris are 4-7 cm long, 1-2 mm wide and green. The anatomy of both tree species needles shows a thick hypodermis and several external resin ducts.38 Thus, differences in the physiology of needles between tree species were not relevant for leaf area and needle surface. Because Slovakia and Norway are in different climate zones, it is also necessary to consider the differences in weather conditions, atmospheric transport, etc. Samples were collected in spring in Slovakia and in autumn in Norway. However, the weather (temperature and precipitation) was comparable between Slovakian mountains in spring and south-eastern Norway in autumn. Two reference sites (Sites 9, 10) in Slovakia where both tree species were sampled, were used to compare the overall accumulation of PFASs at the beginning of spring 2015. The sum of PFAS concentrations was 12 ng g-1 dw for Pinus mugo and 10 ng g-1 dw for Pinus sylvestris in Zilina (Site 9), and 25 ng g-1 dw and 18 ng g -1 dw respectively at Kopske seddle (Site 10). It should be noted that the ability to accumulate pollutants depends on the chosen tree species. In the case of this presented study, no marked differences were observed that would prohibit comparison of results across the chosen species. However, many factors may affect the process of sampling, analysis and evaluation of results.

258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274

Relative distributions Relative distribution profiles for the quantified PFASs were used for comparison of all samples. Significant differences in both distribution patterns and concentrations were found between Slovakian and Norwegian locations (Figure 3). Perfluorooctanoic acid (PFOA) had the highest relative abundance in all Slovakian samples (8 – 93%). The lowest PFOA concentrations were at the two reference sites (Sites 9, 10). Zilina (Site 9) is a typical industrial location. Here PFOA was 20% of the overall PFASs and the absolute PFOA concentration was four times lower compared to the remote skiing areas. Globally, fluoropolymers manufacturing has been identified as the main direct emission source of PFOA. These direct emission sources have decreased continuously in the USA, Europe and Japan during the past years.8 Indirect PFOA emission sources are typically manufacturing, usage and disposal of PFOA-containing products. This includes products containing PFOA as a direct ingredient or impurity and products where fluorinated ingredients (precursors) may degrade to PFOA, as reported earlier.39–42 Due to documented use of PFOA in ski waxes, their occurrence in high mountains areas may also be associated with ski resorts. Information about particular product composition and 9 ACS Paragon Plus Environment


275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315

PFAS ingredients cannot be confirmed officially, because the composition of ski waxes is confidential. However, investigations on exposed skiers identified high PFOA levels. 43,44 The positive reference location Kopske seddle (site 10), where PFAS contamination was expected because of skiing activities, had a more diverse PFAS profile. PFOA at Kopske seddle was 8%, which is the lowest value from all Slovakian sites. Abundant substances from Kopske seddle and other the Slovakian samples were longerchain PFASs (C8-C12: PFNA=18%, PFDA=19 % and PFDoDA=13%). Perfluorinated carboxylic acids with a carbon chain of 11 to 14 carbon atoms are listed as substances of very high concern on the REACH candidate list because of their very persistent and very bioaccumulative properties.8 Currently, long chain PFASs are replaced with shorter alkyl chain compounds in various PFOA-containing products (incl. ski waxes). Short alkyl chain PFAS usually have similar functional properties to the longer chain compounds 45,46 including comparable environmental stability, but they are not as bioaccumulative and appear to have a less pronounced toxicity profile.47 Kopske seddle (Site 10) is not only near the local ski resort, but it is also close to the small town of Zdiar, which provides accommodation for tourists in many hotels. Zdiar is the gateway to the Eastern Tatra Mountains and it is a tourist area for hiking during spring and summer. Possible sources of longer-chain PFASs may be seasonal tourist activities (impregnated outdoor clothes and products of everyday use as PFAS source). A deviation from the overall PFAS pattern was also found for Krivan (Site 4), where relatively low level of PFOA (similar in references sites 9 and 10 mentioned above) was reported (26% of total PFASs). At Sites 4 and 9, the samples were characterised by a high abundance of PFBA (72% and 59% of total PFASs, respectively). Zilina (Site 9) is typical of an industrial town and also close to Czech and Polish borders, and thus the influence of industrial activities (mining, manufacturing) from Czech Republic is expected. Also southern Poland is the most industrial part Poland this can influence Slovakia through atmospheric transport. However, despite of high PFBA contributions, Zilina is the least contaminated of the Slovakian sites. Krivan (Site 4) is near Zilina (Site 9) and the relative distribution of PFBA was similar. At all other Slovakian sample sites PFOA was the predominant PFAS (>65 % of total PFASs). Compared with the Slovakian pine needle samples, the levels from Norwegian sites had a different trend of PFAS distributions and concentrations. PFOA was the only PFAS detected and quantified in all analysed samples (Slovakian and Norwegian) but the relative distribution differed considerably between Norway and Slovakia (Norway: 4 – 39%). The lowest concentrations of total PFASs were found near the capital, Oslo (Site 18). Only 3 out of 16 analysed compounds (PFOA, PFHpS and PFOS) were detected there. However, PFOA was found in all Norwegian sites. These results clearly demonstrate the concentration and pattern differences between Slovakian and Norwegian recreational sites. The PFOA levels found in Slovakian samples are usually one order of magnitude higher than those found in Norwegian samples (Figure 4). The potential for direct uptake into exposed humans can, thus, not be neglected. Nilsson et al. 44 reported elevated levels in whole blood samples from professional ski wax technicians 10 ACS Paragon Plus Environment

Page 10 of 21

Page 11 of 21

316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340


and compared his results with levels found in general Swedish population. In professional technicians, levels were up to 112 ng mL-1 for PFOA. These occupational levels were around 45 times higher than in the general Swedish population.44 Increased concentrations of PFOA associated with skiing activities were also confirmed in other studies in blood serum, snow, soil and air.32,48 Since 2011, the usage and production of PFOA has been banned by Norwegian regulations. National monitoring programs report stagnant levels of PFOA in a variety of environmental compartments.49 In addition, the C9-C14 PFASs are listed on Norway’s Priority List of Hazardous substances.49 Additionally, several polyfluorinated substances are currently considered as precursors to PFOA under environmental conditions, and may thus be directly transformed into PFOA during biotic and abiotic transformation in the environment. The PFOA profile observed in this study may thus be a combined result of primary emissions and transformation from precursors under environmental conditions. In Norway, the most abundant PFASs were perfluorobutanoic acid (PFBA): 3 – 66% which, however, was not detected at Hafjell (Site 12) and Oslo (Site 17); and perfluoropentanoic acid (PFPA): 21 – 85% which was not detected in and in the vicinity of Oslo (Sites 15-17) as well as in Kongsberg (Site 14). The highest concentrations of PFPA were found in Hafjell (Site 12) and Ås (Site 18) where PFBA was absent or is low. In general, shorter chain PFASs (chain length C4-C7) are more common in Norway. PFNA, PFDA, PFUnDA and PFTeDA were not detected which obviously reflects again the effect of the Norwegian national PFAS regulations.49 Distinct differences in distributions between the sampling sites in Norway and Slovakia were also found for perfluoroheptane sulfonate (PFHpS). In Norway, PFHpS was found at all sampling sites except Kongsberg (Site 14), whereas in Slovakia PFHpS was detected only at Kopske seddle (Site 10). 100 PFBA PFPA PFHxA PFHpA PFOA PFNA PFDA PFUnDA PFDoDA PFTrDA PFTeDA PFBS PFHxS PFHpS PFOS PFDS

80

60 % 40

20

0

341 342 343 344

1

2

3

4

5 6 Slovakia

7

8

9

10

11

12

13

14 15 16 Norway

17

18

Figure 3: The relative distribution of PFASs in two-year-old needles from Slovakian sites (Sites 1 – 10) and Norwegian sites (Sites 11 – 18)



345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385

Comparison of overall concentrations The comparison of the total PFAS concentrations at Slovakian and Norwegian sites (Figure 4, Table S5) revealed higher Sum PFAS levels in Slovakia compared to Norway. The highest PFAS levels in all samples were found at Krivan (Site 4). However, the dominance of PFBA (72% of total PFASs) most probably reflects direct atmospheric transport from Polish industrial areas near to rural Krivan. Contamination at other Slovakian sites is similar with respect to levels and distribution patterns. PFOA dominated the remaining Slovakian sites 1 – 3 and 5 – 8. At a first glance, the reference sites showed obvious differences in patterns. However, the relatively high concentration in Zilina (Site 9, negative reference site) was most probably caused solely by high PFBA contribution (59%). Except for PFBA concentration, Zilina, as an urban site, was obviously the least contaminated Slovakian site. For the Kopske seddle mountain station (Site 10, positive reference site), high levels for all perfluorinated compounds (C6 – C10) were confirmed. For Norwegian sites, the highest levels were reported for Oslo winter park (Site 11) close to Voksenkollen. The pine trees selected for sampling were usually located in the vicinity of the ski school, near ski tracks, but as far as possible from the city centre, industrial activities as well as residential areas. Ski schools are usually also locations for technical support for skiers and places for ski rentals. Therefore, ski waxes may be more widely used in these locations. Our results confirmed also a recent study by the Norwegian Institute for Air Research (NILU) where elevated levels of PFASs were identified in earthworms from the Voksenkollen area, located in the vicinity of our sampling site.50 The presence of PFAS in this location is exclusively explained by the comprehensive usage of ski waxes due to skiing activities.50 The contamination levels for the other Norwegian sites are low and found to be similar for all samples. All selected sampling sites are used for various skiing activities, e.g. Hafjell, Kongsberg (Sites 12, 14) are typical Norwegian winter sports centres with cross-country ski tracks and downhill skiing facilities; Birkebeineren and Holmenkollen (Sites 13, 15) are biathlon and cross-country arenas; both sampling sites at Holmenkollen (Sites 13, 14) are also known for international ski jumping competitions and events. The Sum PFASs concentration found at the positive reference site in Ås (Site 18, along the local cross-country track) were higher compared with the typical Norwegian ski areas, suggesting additional domestic and municipal sources in the Ås municipality. These results confirmed again that several PFAS sources exist in this type of location and that elevated levels in the environment are usually caused by a combination of product use (waterproof textiles), diffusive sources (waste, disposal sites), industrial and protective applications (i.e. large scale application of aqueous film forming foams (AFFF) at firefighting facilities) and recreational activities (clothing, other impregnated textiles and surfaces, as well as ski surface preparation utilities). The negative reference site in Oslo (Site 17) is situated in the city centre near a park facility. Site 17 had low PFAS concentrations, as expected. Compared with the positive reference site in Ås, the PFAS levels were around 7 times lower (Figure 4). 12 ACS Paragon Plus Environment

Page 12 of 21

Page 13 of 21


35

PFOA SUM of PFASs

30

1

386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417

2

6 5 Slovakia

9

10

11

12

13

14 15 Norway

16

17

6%

40%

15%

9%

11%

0

10%

25%

4%

8

9%

7

20%

93%

4

86%

3

83%

5

91%

26%

10

65%

15

94%

20 86%

-1

ng g dw

25

18

-1

Figure 4: Concentration of PFOA (with the percentage content) and total Sum of PFASs (ng g dw) in second year of needles in Slovakian sites (Site 1 – 10) and Norwegian sites (Site 11 –18)

Trend estimates To assess the long-term status of the exposed environment, four sites with needles of all age classes were selected (two from each country) for comparison. After sampling, the pine needles were divided into specific year classes and analysed separately. In Slovakia, Martinske hole (Site 1) and Kopske seddle (Site 10) were chosen, with needles of Pinus mugo according to five year classes. For the Norwegian sites, Oslo winter park (Site 11) and Birkebeineren (Site 13) were selected. Pine needles from Pinus sylvestris were collected according to three year classes. The summarised results are shown in Figure 5 and Table S6 (SI). The possibility of monitoring different year classes of pine needles is considered as a favourable feature for long-term temporal trend studies and environmental monitoring. In the case of pine needle samples, the uptake of airborne volatile POPs into the cellular parts of vascular plants is heavily influenced by the amount of endogenous volatile oils.51 Previous studies on pollutant levels in needles have shown that the adsorption properties for selected pollutants increase in the second year of the needle lifetime and decrease again at the end of needle lifetime because of reduced physiological fitness.22 The accumulation with age until the onset of senescence applies to all plants generally. In the case of this study, it is necessary to consider that the samples were collected in late spring in Slovakia and in autumn in Norway. A large seasonal differences in the accumulation rate during spring and summer can be observed for selected POP compounds.51 Kylin et al. 52 proved that the accumulation of α-HCH in Pinus mugo needles from two different sites had a general trend of increasing concentrations during needle lifetime, except the last available year when senescence had started. The theory that the previous year-class starts losing contaminants 52 was confirmed for Pinus mugo (Sites 1, 10) at the Slovakian sites. This assumption was also confirmed for selected POP compounds in a recent publication of a four-year-long study, with a considerably higher number of samples.53 However, considerable variations in the PFAS distribution profiles limit the overall validity of this hypothesis. Thus, these results should only be considered as indicative. In addition, 13 ACS Paragon Plus Environment


420 421 422 423 424 425 426 427 428 429 430 431

PFOA SUM of PFASs

20

432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449

1st

2nd

3rd 4th Site 1

5th

3rd 4th Site 10

5th

1st

2nd 3rd Site 11

21%

3%

4%

23%

79%

2nd

70%

1st

3%

0

9%

5

51%

89%

95% 83%

86%

10

79%

-1

ng g dw

15

1st

4%

419

immediate changes in environmental conditions (i.e. temperature variations, irradiation etc.) may cause increased/decreased sorption capability or even desorption for selected pollutants and, thus obscure the age-related adsorption profiles (increased concentration variation). Since sampling was carried out in the late spring/early summer period, another explanation for the concentration variation can be also due to various terpenoids content that are present in the needles during the warm and dry summer months.51 For Pinus sylvestris (Sites 11 and 13), Kylin et al. 27 reported that the adsorptive capability for selected persistent pollutants increases during the entire lifetime of needles. This assumption is supported by these results. A considerable increase in concentration of Sum PFASs is reported for the second and also for third year needles (Pinus sylvestris) for both Norwegian sites. Despite the indicative results, this study is only an evaluation of two sites from each sampling country, and therefore the number of samples is small and the results serve only as a semi-quantitative assessment of trend estimates.

10%

418

Page 14 of 21

2nd 3rd Site 13 -1

Figure 5: Concentration of PFOA (with the percentage content) and total Sum of PFASs (ng g dw) in one-to five-year-old needles in Slovakian sites (Site 1, 10) and in one-to three-year-old needles at Norwegian sites (Site 11, 13)

Altitudinal patterns and distance to primary sources For selected Slovakian sites (Sites 1, 2, 3, & 4), the samples were collected along an elevation gradient which also reflects distance to potential primary sources. Sites 1 and 2 as well as 3 and 4 were compared according to the previously described site characteristics. The results were examined with respect to prevailing wind direction and distance to potential contamination sources considering the contribution of long-range atmospheric transport (from industrial, recreational and domestic sources). For sites 6 and 7, sample transects followed an elevation gradient (Figure 6 and 7, Table S7). For these sites, the lowest point was sampled at 1515 m a.s.l and the highest at 1756 m a.s.l. For a more complete source characterisation at the area, the PFAS levels were combined with previously reported concentrations of legacy persistent organic pollutants (POPs: polychlorinated biphenyls – PCBs, hexachlorocyclohexane isomers – HCHs, dichlorodiphenyltrichloroethane derivatives – DDTs) from the same location 22 (SI, Table S7). 14 ACS Paragon Plus Environment

Page 15 of 21

450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490


The expectation was that ski-preparation (i.e. ski waxes) and outdoor textile products are the predominant source of PFAS in the locations used for winter sport activities, whereas POP contamination is usually caused by diffusive emissions from municipal installations and long-range transport. Therefore, we expected different trend patterns for each pollutant group. This was expected to provide complementary information for complete source apportionment of the identified pollution profiles. The results of a previously reported study 22 confirmed the highest concentrations of POPs at areas in the vicinity of industrial locations. Long-range transport was identified as the second most important source in the high mountains habitats. The highest concentrations were found in areas with prevailing winds from the Czech Republic and Poland, as these are considered potential source areas. However, no clear influence of long-range atmospheric transport was observed for PFAS at the selected skiing resorts. This may indicate the dominance of local pollution sources. For Martinske hole Mt. (Sites 1, 2) similar trends were found for PFASs and POPs (Figure 6, 7). The sampling site was located on the eastern side of the mountain, and is highly influenced by contamination transported from residential and industrial areas around the city of Martin. A large popular skiing resort is situated close to the eastern mountain site in the vicinity of the city. This may be the reason for the elevated POP and PFAS concentrations (caused by potential local contamination sources). Low PFAS levels were observed at the sampling location on the west side of the mountain (given the absence of a local ski resort). Here long-range atmospheric transport is considered the only source of PFAS contamination. The concentration of POPs found in the sampling regions was slightly elevated. Thus a considerable contribution from long-range atmospheric transport from Czech Republic may be assumed. The opposite trend was observed at the Krivan Mountain range (Sites 3, 4). The concentration of POPs at these sites showed no marked differences between the north and south-western locations (Figure 7), suggesting that industrial activities are contributing to the POP contamination at both locations in a similar way. However, for PFAS patterns, several distinct differences in source and distribution profiles were identified. On the north side of the mountain, a large ski resort is present. Therefore, we assume that this could be a major reason for the elevated PFAS levels found in the needles. The PFAS concentration, however, is increasing slightly (comparing site Martinske hole) towards the south-western sampling locations (Figure 6), and, the increasing PFAS patterns are mainly dominated by PFBA and PFPA, indicating primary sources. At Sivy vrch Mt. (Sites 6, 7) a transect of samples along an elevation gradient was collected in 2014 comprising of five sites (1515 m a.s.l. – 1756 m a.s.l.).22 Sivy vrch Mt. is influenced by air masses moving from the north and the southern side thereby passing industrial locations as well as densely populated areas as potential source areas. Thus, we assumed that the air mass movement and direction from the north side was contaminated by the north industrial area, while air masses on the south side are in contact with emissions from the residential area. Air masses from the northern side pass over the mountain ridge and are further contaminated by emissions from the southern side. These air masses then turn in the 15 ACS Paragon Plus Environment


491 492 493 494 495 496 497 498 499 500 501 502 503 504 505

opposite direction during favourable meteorological conditions and move back again to the lowest transect site.22 Consequently, the highest POP contamination was found at the lowest point of the transect. The second highest concentrations were found on the highest point of transect (Figure 7). The lowest and highest point of transect, again, were chosen for PFASs analysis. In contrast to the POP profiles (Figure 7), the PFAS levels do not show marked differences between the lowest and highest sampling points (Figure 6). The PFAS levels reported are higher at the highest transect point. Therefore, the industrial areas in vicinity of Sivy vrch Mt. do not affect the concentration of PFAS along the mountain range. Because only 4 sites (Sites 1, 2, 3 and 4) were used to evaluate the influence of distance to primary sources and only 2 sites (Sites 6 and 7) for evaluation of transects, these results are not strictly conclusive. These results provide a basic view on the influence of local sources, long-range transport, slope of exposure and elevation on concentrations of selected POPs. Confirmation of these hypotheses requires more detailed sampling and research on PFAS accumulation in pine needles. Mainly because this is the first study concerning on presence of PFAS compounds in pine needles.

35 30

PFOA SUM of PFASs

-1

ng g dw

25 20 15 10 5 0 E W 1 2 Martinske hole

506 507 508 509 510

SW 3

N 4 Krivan

lowest highest 7 6 Sivy vrch

Figure 6: Concentration of PFOA and total Sum of PFASs (ng g-1 dw) in two-year-old needles in Slovakian sites Martinske hole Mt. (Site 1, 2), Krivan Mt. (Site 3, 4) and Sivy vrch Mt. (Site 6, 7) depending on slope of exposure and elevation


Page 16 of 21

Page 17 of 21


1400 1200

SUM of PCBs SUM of HCHs SUM of DDTs

800

-1

pg g dw

1000

600 400 200 0 E W 2 1 Martinske hole

511 512 513 514

SW 3

N 4 Krivan

lowest highest 7 6 Sivy vrch

-1

Figure 7: Concentration of total Sum of PCBs, HCHs, DDTs (pg g dw) in two-year-old needles in Slovakian sites Martinske hole Mt. (Site 1, 2), Krivan Mt. (Site 3, 4) and Sivy vrch Mt. (Site 6, 7) depending on slope of exposure and elevation

515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532

In conclusion, significant regional and local differences in PFASs distribution patterns and concentrations between ski resorts in Slovakia and Norway were identified. The nationspecific PFAS regulation contributed specifically to the PFAS profiles identified in the respective countries. This study provided important information on PFAS source characterization in remote ski areas. Source elucidation were performed for a characteristic set of priority pollutants including legacy POPs and PFASs. This evaluation further confirmed the contribution of multiple primary sources to the overall contamination profile of the respective recreational skiing resorts. Study provided scientifically sound information on the comprehensive value of pine needles as passive samplers and as a monitoring tool for spatial and temporal PFAS distribution profiles, as well as other priority organic pollutants. We therefore encourage regulatory authorities and the research community to further develop the concept and consider this analytical strategy for implementation in long-term national pollutant monitoring programs. Specifically, Pinus mugo as sample medium has previously been used only once, by our research group 22. This study provided sampling and analytical approaches suitable for monitoring in response to national and international regulations and legislative restriction for application of chemicals, as demonstrated here for PFASs.

533 534 535 536 537 538 539 540

Supporting information Tables showing the geographical coordinates and elevation of sampling sites in Slovakia and Norway; MS parameters for PFASs compounds (DP - declustering potential [V], EP - entrance potential [V], CE - collision energy [V], CXP - collision cell exit potential [V]); percentage recovery of native PFASs; concentration of PFASs in ng g-1 dw and

Pine Needles for the Screening of Perfluorinated Alkylated

Recommend Documents