| 1. |
- Cousins, Ian, et al.
(författare)
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Reconciling measurement and modelling studies of the sources and fate of perfluorinated carboxylates
- 2011
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Ingår i: Environmental Chemistry. - 1448-2517 .- 1449-8979. ; 8:4, s. 339-354
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Forskningsöversikt (refereegranskat)abstract
- This study critically evaluates the recently published measurement and modelling studies of the sources and fate of perfluorinated carboxylates (PFCAs). It is concluded that modelling studies provide support to the 'direct hypothesis' for PFOA and PFNA (i.e. the global dominance of direct sources (mainly from fluoropolymer manufacturing)). Empirical evidence for the importance of direct sources of PFOA and PFNA is provided by PFNA : PFOA ratios and isomer profiles of PFOA in ocean water. However, homologue patterns of long-chain PFCAs in biota from remote regions suggest that indirect sources (mainly from precursor degradation) are proportionally more important for PFCAs with more than 10 carbons. Temporal data in biotic and abiotic media are reviewed and an increasing trend to 2000 is observed for all PFCAs, with discrepancies in time trends reported after that period. Some studies on temporal patterns report a levelling off or decline in the latter part of the 2000s for PFOA and PFNA, whereas others show a continual increase throughout the study period. Differences in temporal patterns result from the fact that some environments respond faster to emission changes than others and may thus be useful to elucidate the importance of direct and indirect sources to different regions.
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| 2. |
- Cousins, Ian T., et al.
(författare)
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The precautionary principle and chemicals management : The example of perfluoroalkyl acids in groundwater
- 2016
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Ingår i: Environment International. - : Elsevier BV. - 0160-4120 .- 1873-6750. ; 94, s. 331-340
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Forskningsöversikt (refereegranskat)abstract
- Already in the late 1990s microgram-per-liter levels of perfluorooctane sulfonate (PFOS) were measured in water samples from areas where fire-fighting foams were used or spilled. Despite these early warnings, the problems of groundwater, and thus drinking water, contaminated with perfluoroalkyl and polyfluoroalkyl substances (PFASs) including PFOS are only beginning to be addressed. It is clear that this PFAS contamination is poorly reversible and that the societal costs of clean-up will be high. This inability to reverse exposure in a reasonable timeframe is a major motivation for application of the precautionary principle in chemicals management. We conclude that exposure can be poorly reversible; 1) due to slow elimination kinetics in organisms, or 2) due to poorly reversible environmental contamination that leads to continuous exposure. In the second case, which is relevant for contaminated groundwater, the reversibility of exposure is not related to the magnitude of a chemical's bioaccumulation potential. We argue therefore that all PFASs entering groundwater, irrespective of their perfluoroalkyl chain length and bioaccumulation potential, will result in poorly reversible exposures and risks as well as further clean-up costs for society. To protect groundwater resources for future generations, society should consider a precautionary approach to chemicals management and prevent the use and release of highly persistent and mobile chemicals such as PFASs. (C) 2016 Elsevier Ltd. All rights reserved.
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| 3. |
- Giovanoulis, Georgios, et al.
(författare)
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Analysis of PFAS, phthalates, alternative plasticizers and organophosphate esters in sludge
- 2020
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Wastewater treatment plants (WWTPs) can be considered a water pollution point source as all potential pollutants from household as well as from certain industry production passes the WWTPs. Therefore, sludge from WWTPs may be enriched with pollutants and is a relevant matrix for screening for both known and hitherto unknown potential hazardous chemicals. If the sludge from municipal WWTPs is to be used as a source of nutrient or other purposes, then it could be necessary to employ methods for removal of micropollutants in the sludge. The present study constitutes an addition to a large-scale experiment focusing on the reduction of pharmaceuticals, antibiotics and hormones in sewage sludge stored over a period of a year.The objective of the present study was to analyse the presence of per- and polyfluoroalkyl substances (PFAS), organophosphate esters, phthalates and alternative plasticizers and their potential degradation/reduction in mesophilic anaerobic digested sludge in different treatments. This study is part of a larger on-going project on reduction of pharmaceuticals and organic pollutants in sludge. Extracts of sludge samples were analysed using three instrumental methods: liquid chromatography coupled to both tandem mass spectrometry (LC-MS/MS) and high-resolution mass spectrometry (LC-HRMS) and gas chromatography coupled to tandem mass spectrometry (GC-MS/MS). Target analysis of several compounds (PFASs, organophosphate esters, phthalates and alternative plasticizers), analysis of total oxidizable precursors of PFASs and a suspect-screening of more than 1000 PFAS were performed at IVL. Extractable organic fluorine (EOF) was also performed on combustion ion chromatography at Stockholm University for quantification of potential unknown fluorinated compounds in the sludge.Decreasing trends for concentrations of organophosphate esters, phthalates, alternative plasticizers and PFAS could be observed in composted sludge over the storage time while the non-composted showed variable time trends for different substance classes. For PFAS, the sum concentrations of target analytes increased by almost an order of magnitude during 12 months of storage in the non-composted sludge. Furthermore, the results from TOP and EOF furthermore suggested that the sludge from both treatment experiments contained a significant fraction PFAS that could not be quantified by the targeted analysis.
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| 4. |
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| 5. |
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| 6. |
- Gomis Ferreira, Melissa Ines, 1987-, et al.
(författare)
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Comparing the toxic potency in vivo of long-chain perfluoroalkyl acids and fluorinated alternatives
- 2018
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Ingår i: Environment International. - : Elsevier BV. - 0160-4120 .- 1873-6750. ; 113, s. 1-9
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Tidskriftsartikel (refereegranskat)abstract
- Since 2000, long-chain perfluoroalkyl acids (PFAAs) and their respective precursors have been replaced by numerous fluorinated alternatives. The main rationale for this industrial transition was that these alternatives were considered less bioaccumulative and toxic than their predecessors. In this study, we evaluated to what extent differences in toxicological effect thresholds for PFAAs and fluorinated alternatives, expressed as administered dose, were confounded by differences in their distribution and elimination kinetics. A dynamic one-compartment toxicokinetic (TK) model for male rats was constructed and evaluated using test data from toxicity studies for perfluorobutanoic acid (PFBA), perfluorohexanoic acid (PFHxA), perfluorobutane sulfonic acid (PFBS), perfluorooctanoic acid (PFOA), perfluoroctanesulfonic acid (PFOS) and ammonium 2,3,3,3-tetrafluoro-2-(heptafluoropropoxy)-propanoate (GenX). Dose-response curves of liver enlargement from sub-chronic oral toxicity studies in male rats were converted to internal dose in serum and in liver to examine the toxicity ranking of PFAAs and fluorinated alternatives. Converting administered doses into equivalent serum and liver concentrations reduced the variability in the dose-response curves for PFBA, PFHxA, PFOA and GenX. The toxicity ranking using modeled serum (GenX>PFOA>PFHxA>PFBA) and liver (GenX>PFOA≈PFHxA≈PFBA) concentrations indicated that some fluorinated alternatives have similar or higher toxic potency than their predecessors when correcting for differences in toxicokinetics. For PFOS and perfluorobutane sulfonic acid (PFBS) the conversion from administered dose to serum concentration equivalents did not change the toxicity ranking. In conclusion, hazard assessment based on internal exposure allows evaluation of toxic potency and bioaccumulation potential independent of kinetics and should be considered when comparing fluorinated alternatives with their predecessors.
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| 7. |
- Gomis Ferreira, Melissa I., et al.
(författare)
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Contribution of Direct and Indirect Exposure to Human Serum Concentrations of Perfluorooctanoic Acid in an Occupationally Exposed Group of Ski Waxers
- 2016
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 50:13, s. 7037-7046
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Tidskriftsartikel (refereegranskat)abstract
- The contribution of direct (i.e., uptake of perfluorooctanoic acid (PFOA) itself) and indirect (i.e., uptake of 8:2 fluorotelomer alcohol (FTOH) and metabolism to PFOA) exposure to PFOA serum concentrations was investigated using a dynamic one compartment pharmacokinetic (PK) model. The PK model was applied to six occupationally exposed ski waxers for whom direct and indirect exposures via inhalation were characterized using multiple measurements with personal air sampling devices. The model was able to predict the diverging individual temporal trends of PFOA in serum with correlation coefficients of 0.82-0.94. For the four technicians with high initial concentrations of PFOA in serum (250-1050 ng/mL), the ongoing occupational exposure (both direct and indirect) was of minor importance and net depuration of PFOA was observed throughout the ski season. An estimated average intrinsic elimination half-life of 2.4 years (1.8-3.1 years accounting for variation between technicians and model uncertainty) was derived for these technicians. The remaining two technicians, who had much lower initial serum concentrations (10-17 ng/mL), were strongly influenced by exposure during the ski season with indirect exposure contributing to 45% of PFOA serum concentrations. On the basis of these model simulations, an average metabolism yield of 0.003 (molar concentration basis; uncertainty range of 0.0006-0.01) was derived for transformation of 8:2 FTOH to PFOA. An uncertainty analysis was performed, and it was determined that the input parameters quantifying the intake of PFOA were mainly responsible for the uncertainty of the metabolism yield and the initial concentration of PFOA in serum was mainly contributing to the uncertainty of estimated serum half-lives.
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| 8. |
- Gomis, Melissa Ines, 1987-
(författare)
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From emission sources to human tissues: modelling the exposure to per- and polyfluoroalkyl substances
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Produced since the 1950’s, per- and polyfluoroalkyl (PFASs) substances are persistent, bioaccumulative and toxic compounds that are ubiquitous in the environment. Being proteinophilic with a tendency to partition to protein-rich tissues, PFASs have been found in human serum worldwide and in wildlife with a predominance of long-chain perfluoroalkyl carboxilic acids (C7-C14 PFCAs) and perfluoroalkyl sulfonic acids (C6-C9 PFSAs). Due to rising concern regarding their hazardous properties, several regulatory actions and voluntary industrial phase-outs have been conducted since early 2000s, shifting the production towards other fluorinated alternatives. This thesis explores the human exposure to long-chain PFASs and their alternatives using different modelling methods and aims to 1) link comprehensively the past and current industrial production with the human body burden and 2) assess the potential hazardous properties of legacy PFASs replacements, on which information is very limited. In Paper I, the historical daily intakes in Australia and USA were reconstructed from cross-sectional biomonitoring data of perfluorooctanesulfonic acid (PFOS), perfluorooctanoic acid (PFOA) andperfluorohexanesulfonic acid (PFHxS). The results indicate that humans experienced similar exposure levels and trends to PFOS and PFOA in both regions, suggesting a common historical exposure possibly dominated by consumer products. The model could not be fitted to PFHxS concentration in serum. In Paper II, the relative contribution of indirect (i.e. subsequent metabolism of precursors into legacy PFASs) versus direct exposure was evaluated on occupationally exposed ski wax technicians. The indirect exposure contributed by up to 45% to the total body burden of PFOA. In Paper III, the physicochemical properties, the persistence and the long-range transport of fluorinated alternatives were predicted using different in silico tools. Findings suggest that fluorinated alternatives are likely similar to their predecessors, in terms of physicochemical properties and environmental fate. Finally, Paper IV compares the toxic potency of PFOS, PFOA and their alternatives as a function of external and internal dose. While alternatives are less potent than their predecessors when considering the administered dose, they become similarly potent when the assessment is based on levels in the target tissue. This thesis demonstrates that pharmacokinetic models are effective tools to comprehensively reconnect the body burden to the exposure of phased-out chemicals. More importantly, the studies on fluorinated alternatives raise the necessity to provide more information and data on the potential hazard of these novel and emerging products.
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| 9. |
- Gomis, Melissa I., et al.
(författare)
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Historical human exposure to perfluoroalkyl acids in the United States and Australia reconstructed from biomonitoring data using population-based pharmacokinetic modelling
- 2017
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Ingår i: Environment International. - : Elsevier BV. - 0160-4120 .- 1873-6750. ; 108, s. 92-102
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Tidskriftsartikel (refereegranskat)abstract
- Perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS) and perfluorohexanesulfonic acid (PFHxS) are found in the blood of humans and wildlife worldwide. Since the beginning of the 21st century, a downward trend in the human body burden, especially for PFOS and PFOA, has been observed while there is no clear temporal trend in wildlife. The inconsistency between the concentration decline in human serum and in wildlife could be indicative of a historical exposure pathway for humans linked to consumer products that has been reduced or eliminated. In this study, we reconstruct the past human exposure trends in two different regions, USA and Australia, by inferring the historical intake from cross-sectional biomonitoring data of PFOS, PFOA and PFHxS using a population-based pharmacokinetic model. For PFOS in the USA, the reconstructed daily intake peaked at 4.5 ng/kg-bw/day between 1988 and 1999 while in Australia it peaked at 4.0 ng/kg-bw/day between 1984 and 1996. For PFOA in the USA and Australia, the peak reconstructed daily intake was 1.1 ng/kg-bw/day in 1995 and 3.6 ng/kg-bw/day in 1992, respectively, and started to decline in 2000 and 1995, respectively. The model could not be satisfactorily fitted to the biomonitoring data for PFHxS within reasonable boundaries for its intrinsic elimination half-life, and thus reconstructing intakes of PFHxS was not possible. Our results indicate that humans experienced similar exposure levels and trends to PFOS and PFOA in the USA and Australia. Our findings support the hypothesis that near-field consumer product exposure pathways were likely dominant prior to the phase-out in industrialized countries. The intrinsic elimination half-life, which represents elimination processes that are common for all humans, and elimination processes unique to women (i.e., menstruation, cord-blood transfer and breastfeeding) were also investigated. The intrinsic elimination half-lives for PFOS and PFOA derived from model fitting for men were 3.8 and 2.4 years, respectively, for the USA, and 4.9 and 2 years respectively for Australia. Our results show that menstruation is a depuration pathway for PFOA for women, similarly but to a lesser extent compared to previous reports for PFOS. However menstruation, cord-blood transfer and breastfeeding together do not fully explain the apparently more rapid elimination of PFOA and PFOS by women compared to men; the intrinsic elimination half-lives in women were up to 13% lower for PFOS and up to 12% lower for PFOA compared to the corresponding half-lives in men.
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| 10. |
- Graae, Lisette, et al.
(författare)
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Miljönyttan av uppströmsåtgärder för minskad spridning av läkemedel till miljön
- 2017
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Det övergripande målet med denna kartläggning har varit att undersöka ett urval av uppströmsåtgärder som genom optimerad användning eller utökad rening av läkemedel kan bidra till en minskning av den totala konsumtionen och därmed utsläppen av läkemedel till miljön och samtidigt öka patientsäkerheten samt bidra till minskade kostnader för samhället. De uppströmsåtgärder som studerats är: i) Återinföra recept på vissa läkemedel/klasser av läkemedel; ii) Utföra läkemedelsgenomgångar på personer/patienter som står på recept och äter fem eller fler mediciner per dag, oavsett ålder eller boendesituation; iii) Förskriva fysisk aktivitet och andra hälsobringande insatser; iv) Installera extra rening av utgående avloppsvatten från sjukhus och vårdinrättningar där behandlingsspecifika läkemedel hanteras; v) Använda offentlig upphandling för att förhindra överanvändning och därmed spridning av läkemedel som kan vara skadliga för miljön. Att göra en kvantitativ uppskattning och jämförelse av samtliga uppströmsåtgärder är inte möjligt i dagsläget då det i många fall saknas tillförlitlig data på hur olika åtgärder skulle påverka utsläppen av läkemedel. Däremot kan en kvalitativ bedömning av den relativa miljönyttan av flertalet av de studerade åtgärderna göras. Baserat på resultatet från studien är bedömningen att effekterna av läkemedelsgenomgångar och separat rening av läkemedelsrester kan uppskattas med relativt god säkerhet. Osäkerheten för vilken effekt dessa åtgärder skulle ha på den totala belastningen av läkemedel till kommunala reningsverk beror framförallt på i vilken utsträckning de tillämpas. Att receptbelägga ett receptfritt läkemedel har troligtvis en tydligt mätbar effekt på användandet av just de läkemedel som får en ändrad receptstatus, men denna effekt varierar också beroende på om det finns ersättningssubstanser med samma verkningsmekanism. För åtgärderna hälsa på recept och offentlig upphandling är det svårare att uppskatta vilken effekt de skulle ha på utsläppen av läkemedel till miljön, men att alla åtgärder som i någon form begränsar överanvändningen av läkemedel i slutänden även uppfyller en miljönytta. Jämförelsen mellan olika åtgärder visar att de verkar på olika tidsskalor. Receptbeläggning, läkemedelsgenomgångar och separat rening från sjukhus skulle ha en nästan omedelbar effekt på läkemedelsutsläpp från det att åtgärden införs. Att förskriva hälsa på recept, å andra sidan, skulle ha en förebyggande effekt på framtida läkemedelsanvändning men med en fördröjning på flera år från det att åtgärden införts. De potentiella miljövinsterna, i form av minskad läkemedelsbelastning, som dessa åtgärder ger måste också utvärderas utifrån konflikt med hälsoaspekter. Hälsa på recept och läkemedelsgenomgångar är åtgärder som i första hand tagits fram med patienthälsan i fokus och därmed ses inga konflikter kring hälsoaspekterna av dessa åtgärder. Separat rening från sjukhus och upphandling skulle troligtvis inte påverka patienthälsan överhuvudtaget. Den enda åtgärd där en eventuell konflikt med hälsoaspekter kan föreligga är vid receptbeläggning av enskilda läkemedel, dvs. beroende på tillgången till läkemedelssubstitut till det läkemedel som receptbelagts.
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