Water contamination through substances called per- and polyfluoroalkyl substances (PFAS) is a worldwide problem. Being able to measure the concentrations of PFAS in water is a first step towards beating this contamination. One alternative is to use a field test kit instead of extensive lab equipment to monitor the contaminated areas. This thesis has investigated the possibility of using amine-functionalized mesoporous carbon as adsorbent to develop a detection method based on adsorbing first PFAS and then dye in aqueous solutions. The non-adsorbed dye concentrations are depending on the amount of PFAS, and hence the colour intensity in the remaining solution is proportional to PFAS concentration. Mesoporous carbon with amine functional groups were chosen as specific adsorbents for PFAS because of its large surface area and high adsorption capacity. It has been shown that some colorants would react in a similar way as PFAS on sorbents and thus can be used as an indicator for the user. In the study, the two most common PFAS, PFOA and PFOS, were studied and Rose Bengal was the dye. The adsorbent’s morphology, pore structure and pore size was verified with scanning electron microscopy (SEM), transmission electron microscopy (TEM) and nitrogen sorption before being tested. Adsorption tests were performed using different PFAS concentrations and a dye solution range in order to find three things: the detection range, the ratio powder/solution in order to see a difference, and the adsorption or saturation time for both PFAS and dye. This thesis concluded that even though the adsorbent was not as efficient as predicted, this method could be used for detecting PFAS concentrations down to at least 0.1 pg/ml and could be a possible approach for quick field tests in the future.

Water pollution is a profound ecological concern, exerting detrimental effects on human well-being, ecological systems, and animal life. Among the emerging contaminants that critically influence water quality and have garnered substantial scientific interest in recent times are per- and polyfluoroalkyl substances (PFAS). It is crucial to investigate the de- velopment of an easy technique for PFAS detection and measurement that can be used for quick analysis. This thesis explores the possibility to use amine-functionalized mesoporous carbon as an adsorbent to develop a detection method based on sequential adsorption of per- and polyfluoroalkyl substances (PFAS) and a dye, Rose Bengal, onto the adsorbent. The hypothesis is that the concentration of non-adsorbed dye is dependent on the amount of PFAS present, making the color intensity of the remaining solution proportional to the PFAS concentration. Mesoporous carbon was chosen as the adsorbent due to their high specific surface area, providing a high adsorption capacity, and the potential to functionalize the surface with amine groups which will attract the PFAS. Rose Bengal was selected as a concentration indicator as it has been shown that it can be used as a proxy for PFAS. In this study, the most prevalent PFAS compounds, namely PFOA and PFOS, were investigated. Prior to testing, the adsorbent underwent characterization using diverse techniques to show the porosity and particle morphology. The adsorption experiments encompassed varying PFAS concentrations and a range of dye solutions to determine the detection range, the powder-to-solution ratio necessary for discernible differentiation, and the adsorption or saturation time for both PFAS and dye. This thesis concludes that it was not possible to detect neither PFOA nor PFOS in the range of 0.1 pg/mL to 1 μg/mL with the setup, even though Rose Bengal adsorption could be detected down to 0.6 μg/mL. It was further observed that amine-functionalized hard templated mesoporous carbon has a higher adsorption capacity compared to the soft templated material.

No description available.

Perfluoroalkyl acids (PFAAs) are man-made chemicals which have been observed in the global environment, even in locations far away from where they are emitted. These persistent substances are taken up in humans and biota and may have toxic effects. Knowledge about how PFAAs are dispersed in the environment is needed to discern strategies to manage their sources and to evaluate the efficacy of adopted legislation. This thesis aimed to increase our understanding of the sources of PFAAs to the atmosphere and how PFAAs are transported in air. The results of Paper I demonstrated that gaseous perfluorooctanoic acid (PFOA) sorbs to typical glass fibre filters (GFFs) used in high-volume air sampling of PFAAs. As a consequence, the fraction of gaseous PFOA present in sampled air is underestimated, while the fraction of PFOA associated with aerosols is overestimated. Replacing GFFs with filters deactivated through silanisation and siliconisation did not eliminate this sampling artefact and is therefore not recommended as a means to determine the gas-particle partitioning of PFAAs. In Paper II, monitoring of the mass of PFOA transferred from water solutions of pH 0.2-5.5 demonstrated that the acid dissociation constant of linear PFOA and the four most ubiquitous branched PFOA isomers is around or below 1. Furthermore, the results demonstrated that the presence of counter ions and organic matter in water retarded, rather than enhanced, the volatilisation of PFOA. Therefore, volatilisation of all isomers of PFOA from environmental waters is expected to be negligible. To further study the transfer of PFAAs from environmental waters to air, Paper III simulated the process of sea spray generation in the laboratory. Strong enrichment of PFAAs was observed from bulk water to the surface microlayer and to aerosols. The enrichment increased with PFAA chain length, indicating that this process is of greater importance for more surface active substances. The highest enrichment was observed in aerosols &lt; 1.6 µm, which can travel over long distances if not rained out. Based on the measured aerosol enrichment factors we estimated that approximately 70 metric tonnes of PFAAs are aerosolised from the global oceans yearly and that 3% of this mass is deposited in terrestrial environments. Paper IV reported the occurrence of branched PFOA isomers in deposition sampled in five geographical locations. The presence of these isomers demonstrated that atmospheric transformation of fluorotelomer alcohols is not the only ongoing source of PFAAs to air. We hypothesised that, additionally, both sea spray aerosols and direct emissions from manufacturing sources contributed to the contamination of the precipitation on different spatial scales. Although further research is required to determine the relative importance of different sources to the atmosphere locally and globally, this thesis has substantially advanced the state-of-the-science by i) demonstrating the significance of an air sampling artefact discussed as an uncertainty in the scientific literature over the past decade, ii) definitively ruling out volatilisation from environmental waters as a source of PFOA to air, iii) demonstrating transfer of PFAAs from seawater to air via sea spray aerosols and thus quantifying the environmental importance of this process, and iv) ultimately demonstrating that several types of sources of PFAAs impact the global atmosphere and thus PFAA contamination patterns in precipitation. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 3: Manuscript. Paper 4: Manuscript.</p>

During the last two decades, the applications of fluorocarbon based chemicals to provide soil resistant or soil release properties for automotive interior and upholstery have increased tremendously. But, recent studies showed that the soil resistant treatment based on fluorochemicals has detrimental effects on the environment as well as on humans due to the presence of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) content. PFOS and PFOA are toxic, bio accumulative and bio persistent fluoro-organic compounds. This project focus on PFOS and PFOA-free soil resistant chemicals and their application on interior textiles used for automotive. Literature study was done by keeping in mind all the aspects regarding soil and nature of soils, soil resistant mechanism, PFOA and PFOS-free soil resistant chemicals, chemistry of the chemicals, area of the application and the method of application. Experimental application of PFOA and PFOS-free soil resistant chemicals by using different concentrations on 100% Polyester dyed and unfinished fabric was performed with Pad-Dry-Cure method. Experimental application was carried out to evaluate the soil resistant treated samples for soil resistant, clean ability and colour change results. At the end, the comparison of the results of three mentioned evaluations gave us the best possible alternatives. / Program: Magisterutbildning i textilteknologi

Background: Prenatal exposure to perfluoroalkyl substances (PFAS) has been associated with lower birth weight in epidemiologic studies. This association could be attributable to glomerular filtration rate (GFR), which is related to PFAS concentration and birth weight. Objectives: We used a physiologically based pharmacokinetic (PBPK) model of pregnancy to assess how much of the PFAS–birth weight association observed in epidemiologic studies might be attributable to GFR. Methods: We modified a PBPK model to reflect the association of GFR with birth weight (estimated from three studies of GFR and birth weight) and used it to simulate PFAS concentrations in maternal and cord plasma. The model was run 250,000 times, with variation in parameters, to simulate a population. Simulated data were analyzed to evaluate the association between PFAS levels and birth weight due to GFR. We compared simulated estimates with those from a meta-analysis of epidemiologic data. Results: The reduction in birth weight for each 1-ng/mL increase in simulated cord plasma for perfluorooctane sulfonate (PFOS) was 2.72 g (95% CI: –3.40, –2.04), and for perfluorooctanoic acid (PFOA) was 7.13 g (95% CI: –8.46, –5.80); results based on maternal plasma at term were similar. Results were sensitive to variations in PFAS level distributions and the strength of the GFR–birth weight association. In comparison, our meta-analysis of epidemiologic studies suggested that each 1-ng/mL increase in prenatal PFOS and PFOA levels was associated with 5.00 g (95% CI: –21.66, –7.78) and 14.72 g (95% CI: –8.92, –1.09) reductions in birth weight, respectively. Conclusion: Results of our simulations suggest that a substantial proportion of the association between prenatal PFAS and birth weight may be attributable to confounding by GFR and that confounding by GFR may be more important in studies with sample collection later in pregnancy.

Perfluoroalkyl substances (PFASs) are contaminants of emerging concern, and have been detected in drinking water, wildlife, humans, and the environment. Cyclodextrins (CDs), cyclic sugars composed of glucose monomers, are proposed as a potential remediation strategy. CDs can form host-guest complexes with hydrophobic molecules; this complexation could be capitalized on for PFAS removal and sequestration. These dissertation projects aim to study the fundamental host-guest interactions between a variety of PFASs and CDs for eventual applications in environmental and biological remediation. 1D and 2D Nuclear magnetic resonance (NMR) spectroscopic methods were employed to determine the strength, dynamics, and structure of the CD:PFAS host-guest complexes. Legacy and emerging PFASs were studied with the three native CDs (α-, β-, and γ-CDs) as well as β-CD derivatives. β-CD and its derivatives exhibit the strongest complexation with all studied PFASs, with association constants of 102-105 M-1, depending on PFAS chain length, functional groups, and branching. The host-guest complex was not significantly disturbed under different environmental conditions, such as changing pH, ionic strength, and in the presence of humic acid. A competition study between perfluorooctanoic acid (PFOA), β-CD, and human serum albumin (HSA), the most abundant protein in blood serum, was then conducted using NMR, circular dichroism, and fluorescence spectroscopies. Excess β-CD was able to totally reverse all PFOA binding to HSA. Finally, the host-guest complex was studied within a biological organism to test its viability as a remediation strategy. The attenuation of the toxicity of PFOA in zebrafish embryos, a model organism for toxicology studies, was tested with β-CD. Excess β-CD increased the LC50 (lethal concentration for 50 % of the population) of PFOA compared to PFOA in the absence of β-CD (p < 0.0001). These dissertation projects suggest that the encapsulation of PFASs by CDs has potential in PFAS remediation strategies.

Per- and polyfluoroalkyl substances are a large group of global environmental contaminants. They can be divided into two sub-groups, 1) perfluoroalkyl acids (PFAAs) and 2) so called precursors, i.e. compounds that can potentially be transformed to form PFAAs. PFAAs are today ubiquitous in wildlife and humans. Food and drinking water are assumed to be the dominant human exposure pathways for PFAAs. The main aim of this doctoral thesis was to develop highly sensitive and fully validated analytical methods for the determination of a range of PFAAs and selected precursors in dietary samples. The methods were based on liquid chromatography coupled to mass spectrometry. Samples were extracted by solvent extraction followed by a cleanup step employing solid phase extraction. The cleanup step could at the same time be used as a fractionation of ionic PFAAs and neutral precursors. Paper I and II describe the development of methods for simultaneous analysis of three groups of PFAAs including perfluoroalkyl phosphonic acids (PFPAs) in drinking water and food. Methyl piperidine was used as ion pairing agent, leading to highly sensitive analysis of PFPAs. A first screening of tap water samples and different food items revealed that human dietary exposure to PFPAs in Europe is currently not of concern. A novel method for simultaneous analysis of perfluoroalkyl carboxylic acids (PFCAs) and polyfluoroalkyl phosphate esters (PAPs) in food and packaging materials is described in paper III. Targeted food samples and their packaging were analyzed. The results showed that PAPs may contribute to human exposure to PFCAs. In paper IV temporal trends (1991-2011) of perfluorooctane sulfonic acid (PFOS) and its precursors in herring were investigated. Rapidly decreasing trends were found for precursors, whereas PFOS did not show a significant change over time. Precursors in fish may have played an important role for human exposure to PFOS in the 1990s but are probably negligible today. / <p>At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 4: Manuscript.</p> / PERFOOD project (KBBE-227525)

BAKGRUND: Per- och polyfluorerade alkylsubstanser, PFAS, är ett samlingsnamn för en stor grupp mycket stabila substanser. Vissa PFAS är klassade som persistenta, bioackumulerbara och toxiska (PBT-ämnen) och har en negativ hälsoeffekt på människor och djur. De är vanligt förekommande i exempelvis brandskum och förhöjda halter finns därför ofta i vattensystem som ligger nära brandövningsområden. Perflourooktansyra (PFOS) är idag den enda PFAS som är förbjuden inom EU och är förmodligen den mest toxiska. Tolerabla gränsvärden finns idag endast för två PFAS; PFOS och PFOA. En av de största källorna för humanexponering av PFOS är fiskkonsumtion, medan PFOA inte brukar vara detekterbar i fisk. SYFTE: Syftet med denna studie var att analysera humanexponering av 11 olika PFAS (PFOS, PFOA, PFHxA, PFHxS, PFHpA, PFNA, PFDA, PFDS, PFBS, PFUnDA och PFOSA) efter konsumtion av abborre (Perca fluviatilis), baserad på analysdata från Stockholms stads miljögiftsövervakning. Då fokus i arbetet framförallt ligger på PFOS så har uppskattat PFOS-intag via denna exponeringsväg jämförts med tillgängliga toxikologiska referensvärden. Likaså syftar arbetet att undersöka hur PFOS- exponeringen via konsumtion av sötvattenfisk förhåller sig till bakgrundsexponering av PFOS i normalbefolkningen. METOD: PFOS-exponeringen via konsumtion av sötvattenfisk beräkandes för tvånivåer av fiskkonsumenter; ”mest sannolik exponeringsnivå” (MSE, där man äteregenfångad sötvattenfisk max 6 ggr per år), och ”hög exponeringssnivå” (HE, där manäter egenfångad sötvattenfisk 1 ggr/vecka). En vidare uppdelning gjordes på”normalkonsumenter” (person som äter normalstora portioner och har en medelvikt) och ”storkonsumenter” (person med låg vikt som äter stora portioner). Beräkningarna grundar sig på tre års analysdata (2015-2017) på abborre från 14 olika vattensystem kring Stockholm stad, vilka kan betraktas som representativa fiskevatten i en urban miljö, utan känd PFOS-påverkan från punktkälla. PFOS-analyser i fisk användes tillsammans med data från litteraturen över fiskkonsumtion och kroppsvikt. Litteraturdata användes även för att beräkna exponeringen i normalbefolkningen viaandra livsmedel och dricksvatten. Även här gjordes beräkningarna för ”mest sannolik exponering” (normalkonsumtion av dricksvatten och normalexponering av PFOS via övriga livsmedel) och ”hög exponering” (storkonsumtion av dricksvatten och högexponering via övriga livsmedel). Därefter jämfördes resultatet med tolerabla dagliga intag (TDI) och PFOS-exponeringen via fiskkonsumtion relaterades till det PFOS-intag som normalbefolkningen blir utsatt för via konsumtion av dricksvatten och andra livsmedel. RESULTAT: I de analyserade proverna av abborrmuskel stod PFOS för ca 90% av PFAS-innehållet, PFOS är den förening som exponeringsberäkningarna gjorts för. Bakgrundsexponeringen för PFOS i normalbefolkningen, via konsumtion av dricksvatten och andra livsmedel (även köpt fisk), beräknades till ca 0,5 ng/kg/dag (vuxna) och 0,7 ng/kg/dag (barn) för den mest sannolika exponeringsnivån (MSE). För den högre exponeringsnivån (HE) beräknades intaget till ca 1,7 ng/kg/dag för både vuxna och barn – alltså väl under EFSAs rådande TDI-värde på 150 ng/kg/dag. Vid jämförelse med dessa bakgrundsnivåer visade sig följande för de 4 exponeringsnivåer som karakteriserats vid konsumtion av egenfångad insjöfisk: MSE – normalkonsument: I denna grupp var PFOS-exponeringen via konsumtionen av egenfångad sötvattenfisk omkring 0,5 ng/kg/dag (vuxna) och 1,1 ng/kg/dag (barn), innebärandes att redan individer som konsumerar egenfångad fisk 6 ggr/år dubblerar sin PFOS-exponering. Det totala intaget ligger dock långt ifrån rådande TDI-värde. MSE – storkonsument: För vuxna och barn beräknades PFOS-exponeringen via sötvattenfisk till ca 1 respektive 2 ng/kg/dag. HE – normalkonsument: För kvinnor blev PFOS-exponeringen 17 ng/kg/dag och för män 18 ng/kg/dag medan resultatet för barn var 37 ng/kg/dag. HE – storkonsument: PFOS-exponeringen från insjöfiskkonsumtion, i detta ”worst-case-scenario”, var 27 och 33 ng/kg/dag för kvinnor respektive män och 69 ng/kg/dag för barn. Hos denna grupp blev exponeringen runt 15 gånger högre än i normalbefolkningens hos vuxna och 40 gånger hos barn. DISKUSSION: Att PFOS stod för den största delen PFAS stämmer väl med förväntat resultat. Studien visar att normal- och storkonsumtion, inom ”den mest sannolika exponeringsnivån”, av sötvattenfisk från de vattensystem i närheten av Stockholm stadsom omfattats av studien, inte utgör någon hälsofara enligt de TDI som gäller idag även om det ger en procentuellt sett stor ökning av PFOS-intaget relativt vad som normalt är att förvänta via intag av livsmedel (även dricksvatten inräknat). Storkonsumenter inomkategorin ”hög exponeringsnivå” utgör ett worst case-scenario, där barn i gruppen kommer upp i ungefär halva TDI. Vid eventuell revidering av TDI så finns risk att både normal- och storkonsumenter, inom ”hög exponeringsnivå”, av sötvattenfisk hamnar påPFOS-intag runt eller över TDI. / BACKGROUND: Per- and polyfluorinated alkyl substances (PFAS) is a group of very stable molecules. Some PFAS are classed as persistant, bioaccumulative and toxic (PBT-substances) with negative impacts on humans and animals. PFAS is a common ingredient in fire foam, and elevated levels are consequently often seen in water systems near fire drill areas. Today, perflourooctanoic acid (PFOS) is the only prohibited PFAS within the EU, and probably the most toxic.Tolerable daily intake (TDI) recommenadtions are only available for two PFAS within the EU; PFOS and PFOA. One of the main exposure routes of PFOS in humans are consumption of fish, whilePFOA usually isn’t detectable in fish. OBJECTIVES: The aim of this study was to analyze human exposure of 11 different PFAS (PFOS, PFOA, PFHxA, PFHxS, PFHpA, PFNA, PFDA, PFDS, PFBS, PFUnDA och PFOSA) after consumption of european perch (Perca fluviatilis) collected from water systems in an urban region of Sweden. The main focus substance of the study was PFOS, where different scenarios of PFOS-exposure after consumtion of perch were compared with toxicological reference values (TDIs) and with background exposure from consumtion of other foods and drinking water. METHODS: The PFOS-exposure from consumption of freshwater fish was calculatedfor two levels of consumers; a “most likely exposure level” (MSE, with a consumptionrate of maximum 6 times/year), and a “high exposure level” (HE, with a consumption rate of at least 1 time/week). The groups were further divided into “normal consumers” (who ate normal portions and had normal body weight) and “large consumers” (who atelarge portions and had a low body weight). The caclulations were based on three years of analysis data (2015-2017) on european perch from 14 different water systems around the city of Stockholm, which can be considered as representative fishing waters in an urban environment, without known PFOS point source. The analyzed PFOS concentrations in fish were used in conjunction with literature data on fish consumption and body weight to assess exposure. Data from the litterature were also used to calculate the exposure in the normal population, after consumption of other foods and drinkingwater. Also here a “most likely exposure level” (average consumtion of drinking water and average consumption rates and PFOS concentrations in other foods) and “high exposure level” (large consumer of drinking water and high PFOS exposure from other foods) were calculated. Thereafter, the results were compared with the tolerable daily intake (TDI), and the PFOS-exposure through consumption of perch was compared to the PFOS-intake following consumtion of other foods and drinking water. RESULTS: PFOS accounted for about 90% of the total PFAS in european perch. PFOS is the compound for which the exposure calculations were made.Background exposure by PFOS in the normal population, through consumtion of drinking water and other foods (including commercial fish), was calculated to 0,5 ng/kg/day (adults) and 0,7 ng/kg/day (children) for the most likely exposure level (MSE). För the higher exposure level (HE) the intake was calculated to 1,7 ng/kg/day for both adults and children, which is far below EFSA ́s current TDI of 150 ng/kg/day. When the background levels are related to the 4 exposure levels characterized after consumption of self-caught freshwater fish the results showed that: MSE – normal consumer: The PFOS exposure from consumption of freshwater fish in this group was 0,5 ng/kg/day (adults) and 1,1 ng/kg/day (children), which means that by consuming self-caught fish 6 times/year the PFOS-exposure will be doubled. Even so, the total intake is far below current TDI. MSE – high consumer: PFOS exposure from freshwater fish were 1 ng/kg/day and 2 ng/kg/day for adults and children respectively. HE – normal consumer: The PFOS exposure for women were 17 ng/kg/day and 18 ng/kg/day for men while the result form children were 37 ng/kg/day. HE – high consumer: The PFOS exposure in this “worst case scenario” was 27 and 33ng/kg/day for women and men respectively and 70 ng/kg/day for children. In this group the exposure were about 15 times higher than the background exposure for adults and 40 times higher for children. CONCLUSIONS: That PFOS accounted for the largest part of PFAS in fish is in accordance with previously published studies. Normal and large consumption offreshwater fish within the “MSE”-group, of freshwater fish, from the water systems near the city of Stockholm which are covered in the study, is not a health risk according to the TDI that apply today. However, it gives a percentually large increase in PFOS intake relative to what is normally expected from food intake (including drinkingwater). High consumers in the “HE”-group constitute a worst case scenario, where children in the group reach a PFOS-exposure of about half of TDI. In the event of a possible revision of TDI also normal consumers in the “HE”-group may close in to, or pass, the TDI-limits.

<p>  </p> <p>Perfluoroalkyl substances (PFAS) are synthetic chemicals that are composed of fluorinated aliphatic chains and are widely used in industrial and consumer products. These chemicals are very stable and persist in the environment. Due to concerns linked with longer chain PFAS, shorter chain chemicals are being used as replacements. There are limited human health data regarding the shorter chain chemicals. In addition, these alternatives are persistent in the environment similar to the longer chain PFAS. The main objective of this dissertation was to assess developmental toxicity of the shorter chain PFAS or shorter chain PFAS with chemical modifications represented by perfluorobutanoic acid (PFBA, C4), perfluorohexanoic acid (PFHxA, C6), perfluorobutane sulfonate (PFBS, C4), and perfluoro-2-proxypropanoic acid (GenX, C6). Overall, the results showed that chain length and functional group are determinants of toxicity of PFAS. All tested PFAS induced one or more developmental adverse outcome, but the effects of each chemical are unique, warranting further studies to address the toxicity of the replacement PFAS. </p>