IVL Swedish Environmental Research Institute

Per- and Polyfluoroalkyl Substances (PFAS) are everywhere around us in society, found in commercial and industrial products, the atmosphere, waste, water (waste, surface, drinking, and ground), soil, plants, animals, and even in our bodies. The use and spread of PFAS is a global societal challenge, affecting even the most remote places on Earth. One of the reasons why PFAS has been an attractive component in many products and industrial applications is their extreme chemical and thermal stability. However, these same properties allow for the persistence of PFAS in the environment, whereby even low PFAS emissions over time can be accumulated and pose a high risk of negative health and environmental effects. Today there are thousands of known and unknown PFAS with widely varying properties and toxicity, which makes both risk assessments and management of this growing environmental problem difficult. According to a national mass balance for PFAS emissions from products and atmospheric deposition are the major sources of PFAS in Sweden.

The amount of PFAS which are environmentally dispersed via wastewater and sewage sludge can be considered a minor part. However, due to the persistence of PFAS, measures to minimize their addition via these pathways may be necessary to reduce the total environmental load. Due to their toxicity and persistence, PFAS have recently become heavily regulated, with many regulatory agencies lowering the accepted PFAS environmental level ranges. Many PFAS have already been banned in Sweden or the EU and assessment grounds or action limits have been defined for various PFAS (e.g., surface water bodies, groundwater and drinking water) to initiate measures to reduce the spread of the substances. Already announced and stricter regulations will further increase the need for measures to minimize human exposure to PFAS and their dispersal in the environment.

Regardless of which measures are implemented, PFAS will remain in the environment for a long time, even if a global ban of the chemicals is implemented. Long-term management of PFAS is thus necessary to removal from the cycle gradually. The focus of mitigation actions should primarily be on heavily contaminated land and landfill leachate. The review of existing data from Swedish wastewater treatment plants WWTP and receiving recipients shows that today’s treatment processes do not remove PFAS. At some WWTP, however, an effective separation of certain PFAS is observed, which should be investigated further. Perfluorooctanoic sulfonic acid (PFOS) levels in many of the investigated inland surface waters receiving effluent from treatment plants and PFAS from other sources/pathways exceed existing limits. In many cases, however, analysis limitations prevent an assessment.

Ongoing activities around various treatment and destruction techniques for PFAS show that there are currently no techniques that achieve a far-reaching PFAS removal from municipal wastewater without significant resource consumption and related costs. For the continued use of sludge as a fertilizer, upstream mitigation is needed, with e.g., disconnection or treatment of PFAS-contaminated leachate. However, several ongoing projects indicate that a certain part of PFAS in wastewater can be removed as a side-effect of advanced treatment for pharmaceutical removal. This report provides guidance to stakeholders on how the PFAS problem can be tackled. It also demonstrates the need to improve and spread PFAS knowledge, particularly those involved with PFAS measurement data, treatment techniques and PFAS in sludge. 

PFAS (Per- and Polyfluoroalkyl Substances) are everywhere around us in society; in products, the atmosphere, waste, wastewater, surface water, drinking water, groundwater, soil, plants, animals and in our bodies. The use and spread of PFAS is a global societal challenge and even the most remote places on earth are no longer unaffected by PFAS substances. One of the reasons why PFAS has been attractive in many products and industrial applications is the substances' extreme chemical and thermal stability. However, the same properties create challenges in the environment as the persistence of PFAS implies that even low emissions over time can be accumulated in different environments with a high risk of negative health and environmental effects. Today there are thousands of known and unknown PFAS with widely varying properties and toxicity, which makes both risk assessments and management of this growing environmental problem difficult.

A national mass balance for PFAS shows that emissions from products and atmospheric deposition are the major sources of PFAS to Sweden. The PFAS-amounts that are spread to the environment via wastewater and sewage sludge can be considered a minor part. However, due to the persistence of PFAS substances, measures to minimize the addition via these pathways may be relevant in order to reduce the total environmental load.

Considering the toxicity and persistence of PFAS, their use has been heavily regulated in recent times and the levels that are considered acceptable in the environment have been lowered. Many PFAS have already been banned in Sweden or the EU and assessment grounds or action limits have been defined for various PFAS in e.g. surface water bodies, groundwater and drinking water to initiate measures to reduce the spread of the substances. Already announced and upcoming stricter regulations will further increase the need for measures to minimize human exposure to PFAS and their dispersal in the environment. Regardless of which measures that are implemented, PFAS will remain in the environment for a long time, even if a global ban of the chemicals is implemented. A long-term management of PFAS is thus necessary with a gradual removal from the cycle. The focus of mitigation actions should primarily be on heavily contaminated land and landfill leachate.The review of existing data at Swedish sewage treatment plants and receiving recipients shows that today's treatment processes do not remove PFAS even of some PFAS are removed and end up in the sludge. At some sewage treatment plants, however, an effective separation of certain PFAS is observed, which should be investigated further. PFOS levels in many of the investigated inland surface waters receiving effluent from treatment plants and PFAS from other sources/pathways exceed existing limits. In many cases, however, analysis limitations prevent an assessment.

Ongoing activities around various treatment and destruction techniques for PFAS show that there are currently no techniques that achieve a far-reaching PFAS removal from municipal wastewater without significant resource consumption and related costs. For a continued use of sludge as a fertilizer, upstream mitigation is needed, with e.g. disconnection or treatment of PFAS-contaminated leachate. However, several ongoing projects indicate that a certain part of PFAS in wastewater can be removed as a side-effect of advanced treatment for pharmaceutical removal.The report also provides guidance to stakeholders on how the PFAS problem can be tackled. In addition, the report shows a great need to improve and spread knowledge about PFAS with, above all, measurement data and knowledge about treatment techniques and PFAS in sludge in order to be able to meet the PFAS challenge.

Vid tre av de största avloppsreningsverken i Sundsvall kommun har IVL genomfört en förstudie med syftet att utreda förutsättningar för en fullskaleinstallation för rening av läkemedelsrester från avloppsvatten. Förstudien visade att det framför allt var hormoner som utgjorde den största risken för negativ påverkan på vattenförekomsten. Eftersom Sundsvall kommun har planer för en framtida utbyggnad med kväverening vid Fillan ARV, föddes en tanke om huruvida en sådan utbyggnad även skulle kunna bidra till att hormonhalterna i utgående avloppsvatten minskar till icke-detekterbara nivåer.

Detta mot bakgrund av att minskade hormonhalter observerats vid avloppsreningsverk med kväverening i södra Sverige. Om motsvarande minskning av utgående hormonhalter skulle observeras vid en utbyggd kväverening i Sundsvall kommun, skulle detta leda till att de observerade miljöriskerna i recipienten eliminerades.Med ekonomiskt stöd från Naturvårdsverket, och med hjälp av en befintlig pilotanläggning för studier av kväverening i kalla klimat via rörliga biofilmsreaktorer med bärare (MBBR), genomfördes under åren 2021 och 2023 en kompletterande förstudie vars resultat presenteras i denna rapport. Projektet har fokuserat på rening av hormoner och hormonstörande effekter vid implementering av kväverening i kalla klimat. Det övergripande målet har varit att öka kunskapen om kväverening och nedbrytning av hormoner vid låga temperaturer och att identifiera kunskapsluckor.

Denna kunskap ska stödja planering och implementering av reningsprocesser vid höga hormonhalter i avloppsvatten i kalla klimat.Föreliggande rapport sammanställer dels kunskap om rening av hormoner och hormonstörande ämnen vid avloppsreningsverk utifrån i huvudsak en svensk kontext, dels resultat från genomförda pilottester vid Fillan ARV i Sundsvall. Genomgående under projektperioden observerades att kväve kunde reduceras med mer än 70 % i genomsnitt. Veckovisa analyser av hormoner och hormonstörande effekter, samt månadsvisa analyser av läkemedelsrester, visade däremot på en stor variation av inkommande halter och reningrader.

En genomgående, och förväntad trend, var att halterna av östrogena effekter följde detekterade halter av både östron och östradiol. Halten av etinylöstradiol, däremot, detekterades inte i något av de analyserade proverna under hela projektperioden. Vid de tillfällen där reduktionsgraden av hormonerna var närmare 80 %, var det fortfarande höga halter av hormoner i utgående avloppsvatten, vilket bland annat kunde förklaras med höga inkommande halter. Inga tydliga samband mellan höga reduktionshalter av hormoner och kväve eller andra processrelaterade aspekter kunde observeras. Detta resultat indikerar att reduktion av hormoner och kväverening i huvudsak utförs av skilda grupper av mikroorganismer. En högre reduktion av hormoner kunde däremot observeras i filtrerade prover relativt ofiltrerade, något som delvis kan förklara den låga hormonreduktion efter MBBR-processen som vid dessa försök saknade en partikelavskiljning. 

Sammanfattningsvis kan det konstateras att hypotesen kring att kväverening effektivt kan rena bort hormoner i kalla klimat med en MBBR-teknik inte kan bekräftas vid de betingelser som utvärderats i denna rapport. Det kunde inte heller bekräftas när temperaturen ökade med 4 °C i processen eftersom ingen signifikant påverkan på reningsgraden för varken hormoner, hormonstörande effekter eller läkemedelsrester kunde observeras. Utifrån data från denna rapport kan det därför konstateras att vid anläggningar i norra Sverige, där höga hormonhalter utgör huvudproblemet avseende påverkan på recipient, kan en avancerad rening för att ta bort hormoner och deras effekter behövas, åtminstone i de fall där biofilmsprocesser såsom MBBR implementeras. 

Projektet ”Kemikaliesmarta åtgärder i förskola” har kartlagt och bedömt förändring i förekomsten av farliga kemikalier i förskolemiljö. Tre kemikaliesmarta tillvägagångssätt har tillämpats: nybyggnation enligt fastighetsägarens miljöstyrningsrutiner som bland annat innefattar val av byggmaterial som är godkända enlig Byggvarubedömningen, ombyggnation med tillämpning av samma rutiner samt genomförandet av kemikaliesmarta åtgärder på nivå 1 i enlighet med dokumentet Vägledning för kemikaliesmart förskola som innebär utfasning av föremål som misstänkt innehålla de farliga kemikalierna från förskolan innemiljö.

Chemical safety assessment requires the inclusion of information on potential transformation products. Such information is often lacking for chemicals considered as alternatives making a comprehensive safety assessment for chemical substitution challenging. To address this challenge a methodological framework for investigating the environmental transformation of alternative chemicals is presented. The developed methodology involves the combined use of in silico tools, biodegradation testing and suspect screening analysis for the prediction and identification of environmental transformation pathways and products.

The proposed framework was applied on three emerging alternative plasticizers to phthalate esters (i.e., DINCH, DEHA and ATBC) under which major first-, second- and third-step transformation products predicted in silico were also successfully identified experimentally. This allowed for a preliminary evaluation of the performance of in silico tools in terms of the predicted transformation pathways and their likelihood of occurrence. At the same time the fast chemical degradation method showed good potential in identifying the key transformation products. The proposed framework can be used to support safety assessments for chemical substitution. Further application of the developed methodology on different chemical groups along with proper optimization of the individual method components is recommended to showcase its efficacy over a larger application area.

Oil spills, the most frequent environmental incidents in Sweden, have decreased in recent years but still pose risks to drinking water and aquatic ecosystems, with about 600 cases registered annually by the Swedish Fire Protection Association. Yet, detailed information about modern fuels and their environmental and human health impacts remains scarce. Hence, this study focuses on enhancing the understanding of the environmental impact of common fuels.This study collected thirty fuel samples of different types: petrol, diesel, fuel oil, and marine gas oil. A selected number of substances in the fuels and the water-soluble phase were analysed using GC-MS.

A crucial step in the analytical method in this project, since the focus was on the effect on sub-surface aquatic life and drinking water production, was to form a stable water-accommodated fraction (WAF) where non-dissolved fuel elements were separated from the water. Since odour properties were of interest, the mixing was extensive, with limited space allowed for gases, meaning that more volatile organic carbons (VOC:s) would be in solution. The chemical analysis focused on identifying and quantifying 50 substances, including aromatic hydrocarbons, aliphatic hydrocarbons, ethers, and esters, plus 17 polycyclic aromatic hydrocarbons (PAH:s) for eight of the samples. These substances were chosen for their significance in interpreting results related to odour and to illustrate the proportion of light and heavy substances in the fuels.Twelve of the thirty fuel samples were selected for odour threshold testing, where a dilution series from the WAF was used to evaluate the intensity of odours at different concentrations. Six samples were chosen for ecotoxicological assessments on crustaceans, algae, and bacteria, offering a comprehensive understanding of the ecotoxicity of the fuel-water mixtures. Four samples were used in tailor-made evaporation experiments to study how volatile fuel components evaporate from the water surface under different temperatures and ethanol concentrations.For odour, three fuels were notably distinguished, namely the fuels containing higher concentrations of ether: 98 Octane petrol and E85 fuel.

While there was significant variability in odour thresholds among different panel members, the concentration of MTBE (Methyl Tertiary-Butyl Ether) in the fuel-water mixtures was generally identified as a precise predictor of odour. Conversely, the lack of ether in diesel fuels made them significantly less prone to cause odour in the WAF.Generally, petrol-specific substances dissolve more readily in water than those in diesel, which only marginally ended up in the water-accommodated fraction. However, ethanol in petrol and RME (rapeseed methyl ester) in diesel favoured the dissolution of hydrocarbons into water. For ether, which is of utmost importance for odour, a strong correlation was observed between the concentration of ether in water and its content in the fuel. Therefore, it is possible to predict the ether concentration in the WAF solely from ether concentration in the fuel, meaning that ethanol did not significantly increase ether solubility.In the case of a fuel spill into surface water, volatile substances like ether or toluene evaporate into the air, reducing the water concentration. The experimental conditions in this study do not reflect actual real-world conditions. The evaporation experiments showed that the evaporation of ether can be predicted based on the WAF ether concentration, water temperature, and ethanol content. It was found that cold water (5 °C) conditions reduce the evaporation rate of ether to almost negligible levels.The ecotoxicological tests showed reproduction inhibitions in crustaceans across all fuel samples. However, the inhibiting effect from HVO (hydrogenated vegetable oil) was only marginally greater than that of the control. Fuel oil and some petrol fuels had detrimental effects on the algae growth, while diesel did not.

The decrease of luminescence of bacteria, an indicator of toxicity, exhibited a similar trend; petrol fuels inhibited luminescence more than diesel. None of the fuels disturbed activated sludge to the extent that respiration was inhibited at toxic levels. This shows that an active sludge is more robust than single organisms, probably due to the diverse bacteria flora.For a drinking water producer, fuels containing water-soluble ethers, such as E85 and 98 Octane petrol, are the most prominent risk. If a spill occurs in the drinking water supply, the production disturbance likelihood depends on the dilution prerequisites below the odour threshold of 1.5-4 µg/L. The study also shows that modern diesel has become an issue of marginal concern for surface water-based raw water sources due to very low solubility and regulations that have reduced the amounts of toxic substances in the products.For freshwater ecosystems, water-soluble petrol-associated substances and hydrophobic toxic substances in fuel oil or EU diesel have the most severe effects during a spill. However, MK1 and HVO diesel only marginally affected the test organisms compared to the control, which represents unaffected organisms.

Fuel spills pose significant environmental risks, particularly to drinking water sources and aquatic ecosystems. Thecomposition of fuels has changed over the decades to reduce fossil greenhouse gas emissions. In Sweden, althoughthe number of spill incidents has declined, with around 600 cases reported annually, there remains limitedknowledge on the environmental and health impacts of modern fuels.

This study aimed to address this gap throughcomprehensive chemical analysis and ecotoxicological assessments of 31 fuel samples, including petrol, diesel, fueloil, and marine gas oil. Using gas chromatography-mass spectrometry (GC-MS), we determined 53 substances,including aromatic and aliphatic hydrocarbons, ethers, esters, and 17 polycyclic aromatic hydrocarbons (PAHs).

Akey focus was on forming a stable water-accommodated fraction (WAF) to isolate non-dissolved fuel elementsfrom water, which is crucial for assessing subsurface aquatic life and drinking water production impacts. Resultsindicated significant differences in fuel odor profiles, with ethers enhancing odor intensity. Petrol componentsshowed higher water solubility than diesel, partly due to ethanol. Ecotoxicological tests revealed varying toxicityacross fuels, with petrol showing the highest toxicity to aquatic organisms, although activated sludge exhibitedresilience.

Fuels containing water-soluble ethers posed the highest risks to drinking water, while modern diesel wasof lower concern due to its low solubility and toxicity. In freshwater ecosystems, petrol and hydrophobic toxins infuel oil had severe effects during spills. Overall, this study offers critical insights into the environmental impact of common fuels, supporting improved risk assessment and management strategies for spill mitigation and water resource protection.

The composition of vehicle fuels has changed since 2018 due to the reduction obligation, which requires that an increasing proportion of bio-based content is mixed into fossil fuels. Since properties such as odour and ecotoxicity are complex and depend on the composition of substances' mixtures, information based on older studies is not applicable. Odour properties are essential for drinking water producers, and ecotoxicity is vital for prioritising remediation efforts in the event of spillage.

The objectives of this study have therefore been to 1) quantify the composition of standard diesel and petrol fuels sold in Sweden, 2) quantify odour thresholds for these fuels in drinking water, 3) investigate the ecotoxicity from HVO (hydrogenated vegetable oil) and diesel with RME additive (rapeseed methyl ester), and 4) investigate whether it is possible to predict odour in water based on concentrations in a fuel/water mixture.In the study, a total of eight fuels were tested, of which four were diesel fuels (HVO 100, MK1 diesel with HVO, MK1 diesel with RME and MK1 diesel) and four contained petrol/ethanol to varying degrees (E85, E05, E10 with bio-petrol and E10). HVO 100 and MK1 diesel with RME were used for ecotox tests on alga, bacteria, and crustaceans, as well as for degradation tests.Petrol/ethanol fuels were more efficiently dissolved in water than diesel fuels. This is because they contain a higher proportion of more water-soluble substances, such as ethers and light aromatic compounds, and the mixture of ethanol in the fuels. The E85 fuel resulted in the highest concentrations of hydrocarbons in the water mixture, even though the proportion of petrol is only 15%. A similar effect on solubility could be observed for RME in diesel fuels, although not to the same extent.The amounts of dissolved ether determined the odour properties of fuels in water.

The 98 octane E05 fuel had the highest ether concentration in the fuel product, while the ether content of E85 was most effectively dissolved in water due to the high ethanol content. The odour thresholds were at 0.0017% in a water/fuel mixture for the E05 fuel and 0.0042% for E85. The ethers so dominated the odour that the methyl tert-butyl ether (MTBE) concentration could accurately predict the smell in an aqueous solution.Overall, the ecotoxicological tests showed mild or no effect from the fuels on the tested organisms. The exception was for the reproduction of crustaceans that were disturbed by MK1 diesel with RME. The low solubility of the two tested diesel fuels in water resulted in too low concentrations of hydrocarbons in the fuel/water mixture for valid degradation tests. 

This report addresses the critical need for standardised methods in microplastic (MP) monitoring to meet the European Union’s goal of reducing environmental MPs by 30% by 2030. Differing definitions of MPs, such as size classifications from EU agencies, ISO, and Swedish EPA complicate data consistency. The report stresses the need for unified standards for MP sampling and analysis to streamline data collection and thereby enable data comparisons. It highlights current challenges in achieving reproducible and comparable MP data due to diverse methods in sampling (across all environmental matrices including water, sediment, biota, and air), sample processing, and detection of MPs.

The report discusses sampling methods used for each different environmental matrix (water, sediment, biota, and air) and points out where standardised protocols exist or are lacking. Consistent protocols, including aspects such as standardised mesh sizes and sampling volumes, are recommended to facilitate reliable comparisons between studies. The report covers all types of sample processing methods ranging from simple single-step processes to complex multi-step procedures and the associated principles. The report emphasizes selecting minimally invasive processes to reduce degradation of already fragile MP collected from field. The four most used methods to detect and quantify MP in the environment, visual analysis, Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, and pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS), are also described. Each method has associated strengths and weaknesses, including compromises when analysing the priority source of MPs (i.e., tyre wears, paint flakes, textile fibres, and secondary MPs).

A table summarising these strengths and weaknesses in detail is provided. Harmonising spectral libraries and improving access to reference materials could help address limitations in the accuracy of polymer identification. In the future, standardised interlaboratory comparison between different accredited laboratories performed regularly for different MP sample matrices are needed to ensure data quality and comparability.The report underscores the importance of quality control and quality assurance practices such as field and processing blanks and recovery tests to ensure data accuracy. Finally, the report recommends potential future work which can help standardise each MP analysis component along the process pipeline to support EU efforts to monitor and mitigate plastic pollution effectively.