| 1. |
- Schönlau, Christine, 1986-, et al.
(författare)
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Effect-Directed Analysis of Ah Receptor-Mediated Potencies in Microplastics Deployed in a Remote Tropical Marine Environment
- 2019
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Ingår i: Frontiers in Environmental Science. - : Frontiers Media S.A.. - 2296-665X. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- To facilitate the study of potential harmful compounds sorbed to microplastics, an effect-directed analysis using the DR CALUX® assay as screening tool for Aryl hydrocarbon receptor (AhR)-active compounds in extracts of marine deployed microplastics and chemical analysis of hydrophobic organic compounds (HOCs) was conducted. Pellets of three plastic polymers [low-density polyethylene (LDPE), high-density polyethylene (HDPE) and high-impact polystyrene (HIPS)] were deployed at Heron Island in the Great Barrier Reef, Australia, for up to 8 months. Detected AhR-mediated potencies (bio-TEQs) of extracted plastic pellets ranged from 15 to 100 pg/g. Contributions of target HOCs to the overall bioactivities were negligible. To identify the major contributors, remaining plastic pellets were used for fractionation with a gas chromatography (GC) fractionation platform featuring parallel mass spectrometric (MS) detection. The bioassay analysis showed two bioactive fractions of each polymer with bio-TEQs ranging from 5.7 to 14 pg/g. High resolution MS was used in order to identify bioactive compounds in the fractions. No AhR agonists could be identified in fractions of HDPE or LDPE. Via a multivariate statistical approach the polystyrene (PS) trimer 1e- Phenyl-4e-(1- phenylethyl)-tetralin was identified in fractions of HIPS and in fractions of the blank polymer of HIPS.
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| 2. |
- De Silva, Amila O., et al.
(författare)
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PFAS Exposure Pathways for Humans and Wildlife : A Synthesis of Current Knowledge and Key Gaps in Understanding
- 2021
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Ingår i: Environmental Toxicology and Chemistry. - : Pergamon Press. - 0730-7268 .- 1552-8618. ; 40:3, s. 631-657
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Forskningsöversikt (refereegranskat)abstract
- Here we synthesize current understanding of the magnitudes and methods for assessing human and wildlife exposures to poly- and perfluoroalkyl substances (PFAS). Most human exposure assessments have focused on two to five legacy PFAS and wildlife assessments are typically limited to targeted PFAS (up to ~30 substances). However, shifts in chemical production are occurring rapidly and targeted methods for detecting PFAS have not kept pace with these changes. Total fluorine (TF) measurements complemented by suspect screening using high resolution mass spectrometry are thus emerging as essential tools for PFAS exposure assessment. Such methods enable researchers to better understand contributions from precursor compounds that degrade into terminal perfluoroalkyl acids (PFAA). Available data suggest that diet is the major human exposure pathway for some PFAS but there is large variability across populations and PFAS compounds. Additional data on TF in exposure media and the fraction of unidentified organofluorine are needed. Drinking water has been established as the major exposure source in contaminated communities. As water supplies are remediated, and for the general population, exposures from dust, personal care products, indoor environments and other sources may be more important. A major challenge for exposure assessments is the lack of statistically representative population surveys. For wildlife, bioaccumulation processes differ substantially between PFAS and neutral lipophilic organic compounds, prompting a revaluation of traditional bioaccumulation metrics. There is evidence that both phospholipids and proteins are important for the tissue partitioning and accumulation of PFAS. New mechanistic models for PFAS bioaccumulation are being developed that will assist in wildlife risk evaluations.
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| 3. |
- Eriksson, Ulrika, 1972-, et al.
(författare)
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Comparison of PFASs contamination in the freshwater and terrestrial environments by analysis of eggs from osprey (Pandion haliaetus), tawny owl (Strix aluco), and common kestrel (Falco tinnunculus)
- 2016
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Ingår i: Environmental Research. - San Diego, USA : Academic Press. - 0013-9351 .- 1096-0953. ; 149, s. 40-47
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Tidskriftsartikel (refereegranskat)abstract
- The level of PFAS (per- and polyfluorinated alkyl substances) contamination in freshwater and terrestrial Swedish environments in 2013/2014 was assessed by analyzing a range of perfluorinated alkyl acids, fluorotelomer acids, sulfonamides, sulfonamidoethanols and polyfluoralkyl phosphate diesters (diPAPs) in predator bird eggs. Stable isotopes ((13)C and (15)N) were analyzed to elucidate the dietary source. The tawny owl (Strix aluco, n=10) and common kestrel (Falco tinnunculus, n=40), two terrestrial species, and the osprey (Pandion haliaetus, n=30), a freshwater specie were included. In addition, a temporal trend (1997-2001, 2008-2009, 2013) in osprey was studied as well. The PFAS profile was dominated by perfluorooctane sulfonic acid (PFOS) in eggs from osprey and tawny owl, while for common kestrel perfluorinated carboxylic acids (∑PFCA) exceeded the level of PFOS. PFOS concentration in osprey eggs remained at the same level between 1997 and 2001 and 2013. For the long-chained PFCAs, there were a significant increase in concentrations in osprey eggs between 1997 and 2001 and 2008-2009. The levels of PFOS and PFCAs were about 10 and five times higher, respectively, in osprey compared to tawny owl and common kestrel. Evidence of direct exposure from PFCA precursor compounds to birds in both freshwater and terrestrial environment was observed. Low levels of diPAPs were detected in a few samples of osprey (<0.02-2.4ng/g) and common kestrel (<0.02-0.16ng/g) eggs, and 6:2 FTSA was detected in a majority of the osprey eggs (<6.3-52ng/g). One saturated telomer acid (7:3 FTCA), which is a transformation marker from precursor exposure, was detected in all species (<0.24-2.7ng/g). The (15)N data showed higher levels in osprey eggs compared to tawny owl and common kestrel, indicating that they feed on a 2-3 times higher trophic level. We conclude that ospreys are continuously exposed to PFAS at levels where adverse toxic effects have been observed in birds.
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| 4. |
- Eriksson, Ulrika, et al.
(författare)
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Perfluoroalkyl substances (PFASs) in food and water from Faroe Islands
- 2013
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Ingår i: Environmental Science and Pollution Research. - : Springer Science and Business Media LLC. - 0944-1344 .- 1614-7499. ; 20:11, s. 7940-7948
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Tidskriftsartikel (refereegranskat)abstract
- Diet and drinking water are suggested to be major exposure pathways for perfluoroalkyl substances (PFASs). In this study, food items and water from Faroe Islands sampled in 2011/2012 were analyzed for 11 perfluoroalkyl carboxylic acids (PFCAs) and 4 perfluoroalkane sulfonic acids (PFSAs). The food samples included milk, yoghurt, crSme fraiche, potatoes, fish, and fish feed, and the water samples included surface water and purified drinking water. In total, nine PFCAs and four PFSAs were detected. Generally, the levels of PFAS were in the lower picogram per gram range. Perfluorobutanoic acid was a major contributor to the total PFASs concentration in water samples and had a mean concentration of 750 pg/L. Perfluoroundecanoic acid (PFUnDA) was predominating in milk and wild fish with mean concentrations of 170 pg/g. Perfluorooctane sulfonic acid (PFOS) was most frequently detected in food items followed by PFUnDA, perfluorononanoic acid, and perfluorooctanoic acid (PFOA). Levels of PFUnDA and PFOA exceeded those of PFOS in milk and fish samples. Prevalence of long-chain PFCAs in Faroese food items and water is confirming earlier observations of their increase in Arctic biota. Predominance of short-chain and long-chain homologues indicates exposure from PFOS and PFOA replacement compounds.
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| 5. |
- Karlsson, Therese, 1987, et al.
(författare)
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Comparison between manta trawl and in situ pump filtration methods, and guidance for visual identification of microplastics in surface waters
- 2020
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Ingår i: Environmental Science and Pollution Research. - : Springer Science and Business Media LLC. - 0944-1344 .- 1614-7499. ; 27:5, s. 5559-5571
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Tidskriftsartikel (refereegranskat)abstract
- Owing to the development and adoption of a variety of methods for sampling and identifying microplastics, there is now data showing the presence of microplastics in surface waters from all over the world. The difference between the methods, however, hampers comparisons, and to date, most studies are qualitative rather than quantitative. In order to allow for a quantitative comparison of microplastics abundance, it is crucial to understand the differences between sampling methods. Therefore, a manta trawl and an in situ filtering pump were compared during realistic, but controlled, field tests. Identical microplastic analyses of all replicates allowed the differences between the methods with respect to (1) precision, (2) concentrations, and (3) composition to be assessed. The results show that the pump gave higher accuracy with respect to volume than the trawl. The trawl, however, sampled higher concentrations, which appeared to be due to a more efficient sampling of particles on the sea surface microlayer, such as expanded polystyrene and air-filled microspheres. The trawl also sampled a higher volume, which decreased statistical counting uncertainties. A key finding in this study was that, regardless of sampling method, it is critical that a sufficiently high volume is sampled to provide enough particles for statistical evaluation. Due to the patchiness of this type of contaminant, our data indicate that a minimum of 26 particles per sample should be recorded to allow for concentration comparisons and to avoid false null values. The necessary amount of replicates to detect temporal or spatial differences is also discussed. For compositional differences and size distributions, even higher particle counts would be necessary. Quantitative measurements and comparisons would also require an unbiased approach towards both visual and spectroscopic identification. To facilitate the development of such methods, a visual protocol that can be further developed to fit different needs is introduced and discussed. Some of the challenges encountered while using FTIR microspectroscopic particle identification are also critically discussed in relation to specific compositions found.
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| 6. |
- Karlsson, Therese, et al.
(författare)
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Provtagningsmetoder för mikroplast >300 μm i ytvatten : En jämförelsestudie mellan pump och trål
- 2018
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Mikroplast (MP) är en föroreningstyp som medför stora utmaningar för provtagning och analys. För att kunna förbättra framtida miljöövervakning så jämfördes här två vanliga metoder för provtagning av mikroplast >300 μm; mantatrål och pump. Sex provreplikat för vardera metod togs under vindstilla förhållanden på ett och samma område under en dag. Provtagningsvolymen för varje replikat var 20 m3 för pumpen och ca 60 m3 för trålen. Efterföljande analys gjordes med visuell bedömning av en och samma person där antropogena partiklar delades in i elva kategorier.I pumpproverna hittades mellan 0 och 8 MPs som i volym räknat gav ett medelvärde av 0,17 MP/m3. I trålproverna varierade antalet mellan 9 och 33 MP som i volym räknat gav en signifikant högre koncentration än i trålproverna med ett medelvärde av 0,32 MP/m3. Resultaten innebar även att för att uppnå en statistisk power på 60 % så skulle tio pumpreplikat behövas för att mäta skillnaden mellan det undersökta området och ett område utan mikroplast. För trålen skulle motsvarande kräva 2 replikat. Alternativt kan en större provvolym ge en ökad säkerhet i och med att fördelningsdata då närmar sig en normalfördelning. Variationerna i mätosäkerhet mellan metoderna bedöms framförallt vara relaterad till skillnad i provvolym och skulle också kunna kompenseras genom ökad pumpvolym, vilket skulle gå något snabbare jämfört med att göra fler replikat.Sammansättningen av MP varierade en del mellan replikaten men bestod främst av expanderad cellplast, filmer, filament, och fragment. I vartdera pumpprov var det i genomsnitt 1,3 filmer och 0,33 expanderade cellplastpartiklar medan trålen hade i genomsnitt 2,5 filmer och 9,2 expanderade cellplastpartiklar. Per volymenhet utgjorde filmer den största delen av MP i prover tagna med pump (40 %), medan cellplast dominerade i trålproverna (46 %). Cellplast tycks därmed provtas mer effektivt med trål vilket kan bero på att den flyter på det översta ytlagret som trålen provtar. Pumpen ligger något lägre i ytskiktet och jämförelsestudien indikerar att de båda provtagarna har en mer jämförbar provsammansättning för partiklar med en mer neutral flytkraft. I denna studie erhölls dock inte tillräckligt stort antal partiklar av olika plasttyper för att tillåta mer ingående statistiska jämförelser mellan provsammansättningarna.Sannolikheten för att få falska nollvärden ökar vid lägre partikelantal vilket börjar få en signifikant effekt under 5 partiklar per prov. Oavsett vilken metod som används är det viktigt att tillräckligt stor volym provtas för att besvara frågeställningar som skillnader mellan olika områden och skillnader mellan olika sorters plast.Bakgrund och syfte med rapportenÄven om metoder för provtagning, extraktion och identifikation av mikroplast har utvecklats snabbt under senare år så återstår ännu flera utmaningar. Flertalet studier publicerar förekomst av mikroplast i sjöar och hav. En av de utmaningarna består i hur vi på ett representativt sätt ska kunna provta en förorening som är så pass heterogen, både till form och också utbredning. En annan frågeställning är huruvida det går att jämföra resultat från två olika provtagningsmetoder. Här jämför vi två metoder som ofta används för att provta mikroplast med storlek över 300 μm i ytvatten; en mantatrål och en pump. Under en dag (10 oktober 2017) togs 6 replikat per metod på samma plats i Gullmarsfjorden utanför Lysekil. Genom att räkna mikroplast och annat mikroskräp i proverna var syftet att undersöka skillnader mellan replikat och skillnader mellan metoderna.Jämförelsen har gjorts på uppdrag av Naturvårdsverket och Havs- och vattenmyndigheten som ett led i arbetet med att utveckla övervakning av mikroskräp.
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| 7. |
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| 8. |
- Mattsson, Anna, et al.
(författare)
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Developmental exposure to a mixture of perfluoroalkyl acids (PFAAs) affects the thyroid hormone system and the bursa of Fabricius in the chicken
- 2019
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Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 9:1
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Tidskriftsartikel (refereegranskat)abstract
- Perfluoroalkyl acids (PFAAs) are ubiquitous environmental contaminants and eggs and nestlings of raptors and fish-eating birds often contain high levels of PFAAs. We studied developmental effects of a mixture of ten PFAAs by exposing chicken embryos to 0.5 or 3 μg/g egg of each compound in the mixture. Histological changes of the thyroid gland were noted at both doses and increased expression of mRNA coding for type III deiodinase was found at 0.5 μg/g egg. Serum concentrations of the free fraction of thyroid hormones (T3 and T4) were reduced by the PFAA mixture at 3 µg/g egg, which is in line with a decreased synthesis and increased turnover of thyroid hormones as indicated by our histological findings and the decreased mRNA expression of type III deiodinase. The relative weight of the bursa of Fabricius increased at a dose of 3 μg/g egg in females. The bursa is the site of B-cell development in birds and is crucial for the avian adaptive immune system. Analysis of plasma and liver concentrations of the mixture components showed differences depending on chain length and functional group. Our results highlight the vulnerability of the thyroid hormone and immune systems to PFAAs.
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| 9. |
- Mattsson, Anna, et al.
(författare)
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Metabolic Profiling of Chicken Embryos Exposed to Perfluorooctanoic Acid ( PFOA) and Agonists to Peroxisome Proliferator-Activated Receptors
- 2015
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Ingår i: PLOS ONE. - : Public Library Science. - 1932-6203. ; 10:12
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Tidskriftsartikel (refereegranskat)abstract
- Untargeted metabolic profiling of body fluids in experimental animals and humans exposed to chemicals may reveal early signs of toxicity and indicate toxicity pathways. Avian embryos develop separately from their mothers, which gives unique possibilities to study effects of chemicals during embryo development with minimal confounding factors from the mother. In this study we explored blood plasma and allantoic fluid from chicken embryos as matrices for revealing metabolic changes caused by exposure to chemicals during embryonic development. Embryos were exposed via egg injection on day 7 to the environmental pollutant perfluorooctanoic acid (PFOA), and effects on the metabolic profile on day 12 were compared with those caused by GW7647 and rosiglitazone, which are selective agonists to peroxisome-proliferator activated receptor a (PPAR alpha) and PPAR gamma, respectively. Analysis of the metabolite concentrations from allantoic fluid by Orthogonal Partial Least Squares Discriminant Analysis (OPLS-DA) showed clear separation between the embryos exposed to GW7647, rosiglitazone, and vehicle control, respectively. In blood plasma only GW7647 caused a significant effect on the metabolic profile. PFOA induced embryo mortality and increased relative liver weight at the highest dose. Sublethal doses of PFOA did not significantly affect the metabolic profile in either matrix, although single metabolites appeared to be altered. Neonatal mortality by PFOA in the mouse has been suggested to be mediated via activation of PPAR alpha. However, we found no similarity in the metabolite profile of chicken embryos exposed to PFOA with those of embryos exposed to PPAR agonists. This indicates that PFOA does not activate PPAR pathways in our model at concentrations in eggs and embryos well above those found in wild birds. The present study suggests that allantoic fluid and plasma from chicken embryos are useful and complementary matrices for exploring effects on the metabolic profile resulting from chemical exposure during embryonic development.
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| 10. |
- Nilsson, Helena, 1974-, et al.
(författare)
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A time trend study of significantly elevated perfluorocarboxylate levels in humans after using fluorinated ski wax
- 2010
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Ingår i: Environmental Science and Technology. - Washington, USA : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 44:6, s. 2150-2155
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Tidskriftsartikel (refereegranskat)abstract
- A time trend study focusing on ski waxing technicians' exposure to perfluorinated chemicals (PFCs) from fluorinated wax fumes was performed in 2007/2008. Levels of eight perfluorocarboxylates and three perfluorosulfonates were analyzed in monthly blood samples from eight technicians, Samples were collected before the ski season, i.e., preseason, then at four AS World Cup competitions in cross country skiing, and finally during an unexposed 5-month postseason period. The perfluorinated carboxylates perfluoroheptanoic acid (PFHpA), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), and perfluoroundecanoic acid (PFUnDA) bioaccumulate, and continued exposure may contribute to elevated levels in ski technicians compared to the general population. The wax technicians' median blood level of PFOA is 112 ng/mL compared to 2.5 ng/mL in the general Swedish population. A significant correlation was found between number of working years and levels of perfluorocarboxylates. The PFOA levels in three technicians with "low" initial levels of PFOA (< 10.0 ng/mL in preseason blood) increased by 254, 134, and 120%, whereas five technicians with "high" initial levels (> 100 ng/mL in preseason sample) were at steady state. PFHxA is suggested to have a short half-life in humans relative the other perfluorocarboxylates. The levels of perfluorosulfonates were unaffected by the wax exposure.
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