To Örebro University

Toxicology-related experts are on a daily basis working with the safety assessment of chemicals for human health and the environment, providing knowledge applied for management and regulation of chemicals. The field of toxicology is undergoing continuous transition away from traditional safety evaluation studies in experimental animals to application of new approach methodologies (NAMs), the use of omics-related technologies, and concepts like next-generation risk assessment. This requires expertise in the new technologies but does not dismiss the need of knowledge for interpretation of in vivo studies and full understanding of chemical exposure data. A survey was initiated in 2022 in the Nordic countries to assess current and future needs for competences in risk analysis. In total, 40 replies were received from Denmark, Finland, Norway and Sweden, while an expert assessment was performed in Iceland. The responses primarily (87.5%) came from national authorities, research institutes, industry/business, and consultants, less from the hospital system, NGOs, and others. The survey shows obvious difficulties in finding competent and trained personnel in all areas in risk analysis. Since the individual Nordic countries lack critical mass, a Nordic initiative for training and education is recommended to counteract loss of competences within chemical risk analysis in the future.

Corporate accountability is central for dealing with environmental and health effects in complex supply chains. When companies hold their suppliers accountable to certain rules or standards, these become disseminated in the supply chain. This study analyses how voluntary restrictions of per- and polyfluoroalkyl substances (PFAS) in paper-based food packaging in Sweden are translated as they travel down the supply chain and their relationship to supplier practice. The multidisciplinary approach draws on both interviews with key actors and chemical analysis of PFAS in food packaging. It shows how demands for accountability for chemicals are translated both horizontally in the industry and vertically in supply chains resulting in a set of interrelated voluntary standards and rules. The chemical analysis detected PFAS in almost half of the samples, but at levels indicating non-intentional use, thereby complying with the disseminated rules. The result shows that the standards largely institutionalize established practices in support of “laggards” rather than push the industry to more radical phase-out of PFAS.

Climate change is driving extreme weather patterns, leading to prolonged droughts and more frequent intense precipitation events. These environmental changes will impact aquatic systems by altering essential water quality parameters such as temperature, redox potential, pH, suspended solids and organic matter, which influence pollutant solubility and determine ecosystem health as well as drinking water production. In this context, sediments play a crucial role as they represent both a sink and source of pollutants. Therefore, sediment toxicity testing is essential for accurate environmental risk assessments. However, there remains a gap regarding comprehensive sediment testing ap-proaches that integrate multiple biomarker responses.

The SEASON project uses an interdisciplinary approach combining strategies of environmental toxicology, analytical chemistry, andhydro geochemistry. The aim is to develop conceptual models for evaluating, understanding and predicting the impact of climate change effects on the fate, bioavailability, and toxicity of pollutants in the aquatic environment. This project focuses on risks associated with sediments contaminated by organic and inorganic pollutants, specifically metals and PFAS (per- and polyfluoroalkyl substances). By studying factors such as temperature, pH, microbial communities, and sediment-water interactions, the project seeks to understand how different climate change aspects affect pollutant behavior in aquatic ecosystems.

The project consists of four sub-projects. Three investigate different chemical groups and mixtures under varying water conditions, using zebrafish (Danio rerio) as the main model organism. These studies will include in vitro and in vivo assays, microcosm experiments, microbiome studies and chemical analyses. The fourth subproject will integrate the results to develop a predictive model for sediment risk assessment.

Sediment contact assays will be performed to evaluate the effects of contaminated samples on zebrafish embryos by measuring teratogenicity, developmental toxicity, behavioral changes, and gene expression. In microcosm studies, we will vary pH and mimic increased precipitation events to assess pollutant toxicity in adult zebrafish including sex-related toxicity differences, reproduction, and behavior. Effect-directed analysis (EDA) will be used to identify key toxicants in the samples. Microbiome analysis using metagenomic sequencing will focus on how contaminated sediments alter bacterial communities, which in turn can affect pollutant distribution and bioavailability. Chemical analyses will quantify PFAS, metals, and their speciation throughout the study. Ultimately, the project will integrate these data to develop models that increase our understanding of the impact of climate change on sediment contamination and aquatic ecosystem health.

Per- and polyfluoroalkyl substances (PFAS) are anthropogenic contaminants commonly found in drainage water from waste management facilities. Within the European Union, these facilities either treat the water locally or transfer it to wastewater treatment plants to reduce harmful emissions. However, PFAS are a broad class of compounds with varying physicochemical properties, leading to different removal efficiencies for adsorbents. Activated carbon and ion exchange resins are effective but costly, and they can become saturated with other contaminants. Therefore, this study aims to explore inexpensive, abundant alternatives for reducing PFAS concentrations in the environment. In Sweden, bark is a by-product of forestry activities, primarily used as fuel in heat and power plants. This study evaluates the ability of pine and spruce bark to remove PFAS from contaminated drainage water. Initial laboratory experiments employed liquid-to-solid ratios of 10 and 20 to assess the performance of both materials. Results indicated that pine bark exhibited better removal efficiencies, particularly when a layered column with pine bark followed by spruce bark was utilized. The overall removal efficiencies for short-chain PFAS (perfluorinated carbons: PFCA C3-C6 and PFSA C4-C5) and long-chain PFAS (PFCA > C7 and PFSA > C6) were below 20%, except for perfluorooctane sulfonic acid (PFOS), which showed reductions of 40% to 80%. The pH of the treated water decreased from 7 to 4 (pine bark) and 5 (spruce bark) after treatment. In a larger-scale trial, a combination of 50% pine bark and 50% spruce bark was tested, achieving similar reductions for PFOS. Although the removal efficiencies were insufficient for exclusive treatment, these materials may be useful in specific applications targeting long-chain PFAS or in conjunction with other treatment methods.

Per- and polyfluoroalkyl substances (PFAS) have been used for decades in a broad range of consumer products and industrial applications. A variety of waste and products containing PFAS inevitably end up at waste management facilities when they are no longer considered useful. Drainage water samples (n = 157) were collected from eight subsections at a waste management facility in Sweden and analyzed for 23 PFAS and extractable organofluorine (EOF). Two different sampling methods were used, grab sampling (n = 32, without filtration) and composite sampling (n = 8, produced by pooling 16 filtered samples taken at the same subsection). Although PFAS have been studied at waste sites, the information is scarce regarding how the concentrations and homologue profiles could differ within the sites. In this study, we investigated if composite sampling could be an alternative to grab sampling for PFAS monitoring purposes. Herein, the PFAS concentrations ranged from <1 to 22 μg/L; the grab samples showed systematic higher concentrations than their corresponding composite sample. Short-chain perfluoroalkyl sulfonic acids (C4 and C5) were the largest contributing sub-class, followed by short-chain perfluoroalkyl carboxylic acids (C4 to C6). EOF was measured up to approximately 140 μg/L F with 99% being unexplained by the fluorine mass balance analysis. The results from this study showed that both sampling methods were comparable for target analysis and that 11 compounds represented most of the PFAS concentrations. However, the discrepancy between the sampling methods was greater for EOF analysis and may be due to the preparation of composite samples and/or due to fluctuating discharges during the sampling period. Composite sampling was observed to be comparable to grab sampling for target analysis.

Per- and polyfluoroalkyl substances (PFAS) are persistent anthropogenic contaminants, some of which are toxic and bioaccumulative. Perfluoroalkyl carboxylic acids (PFCAs) and perfluoroalkyl sulfonic acids (PFSAs) can form during the atmospheric degradation of precursors such as fluorotelomer alcohols (FTOHs), N-alkylated perfluoroalkane sulfonamides (FASAs), and hydrofluorocarbons (HFCs). Since PFCAs and PFSAs will readily undergo wet deposition, snow and ice cores are useful for studying PFAS in the Arctic atmosphere. In this study, 36 PFAS were detected in surface snow around the Arctic island of Spitsbergen during January-August 2019 (i.e., 24 h darkness to 24 h daylight), indicating widespread and chemically diverse contamination, including at remote high elevation sites. Local sources meant some PFAS had concentrations in snow up to 54 times higher in Longyearbyen, compared to remote locations. At a remote high elevation ice cap, where PFAS input was from long-range atmospheric processes, the median deposition fluxes of C2-C11 PFCAs, PFOS and HFPO-DA (GenX) were 7.6-71 times higher during 24 h daylight. These PFAS all positively correlated with solar flux. Together this suggests seasonal light is important to enable photochemistry for their atmospheric formation and subsequent deposition in the Arctic. This study provides the first evidence for the possible atmospheric formation of PFOS and GenX from precursors.

Waste management facilities are a known source for per- and polyfluoroalkyl substances (PFAS) to the environment. In this study, water samples from seven subsections within a waste management facility in Sweden were analyzed for PFAS and extractable organofluorine (EOF). Oxidative conversion was used to investigate how much PFAS precursors could contribute to the EOF. Out of the 23 analyzed PFAS, ten compounds accounted for a major proportion of the concentrations. Before oxidative conversion the ∑10PFAS were between 0.44 μg/L and 17 μg/L. The EOF ranged from 2 μg/L F up to 79 μg/L F. There was a greater difference in concentrations and profiles between the subsections in comparison to the four sampling dates at respective sampling point, suggesting different sources of PFAS from the waste. Oxidative conversion revealed presence of precursors by elevated concentrations of perfluoroalkyl acids after oxidation, which increased the explained EOF up to 25%. Seven samples from one sampling date were selected to investigate if other fluorinated compounds (inorganic anions, ultra-short-chain PFAS, and zwitterions) could be a part of the unexplained EOF fraction. The contribution of fluorine from tetrafluoroborate and hexafluorophosphate were equal or higher proportions than the ∑10PFAS. The presence of the ionic liquids tetrafluoroborate and hexafluorophosphate could originate from battery waste, due to their use as counter ions in batteries. Ultra-short-chain PFAS increased the explained EOF by an average of 8%, with trifluoroacetic acid and trifluoromethane sulfonic acid being the main contributors. However, the reported concentrations of ultra-short-chain PFAS, were underestimated due to low recovery by the additional washing step to remove inorganic fluoride for EOF analysis. The concentrations of zwitterions were low and increased the explained EOF by < 1%. Our results suggest that EOF, selected PFAS, oxidative conversion and anionic fluorinated substances give a better picture of PFAS contamination.

Per- and polyfluoroalkyl substances (PFAS) are a group of persistent organic contaminants of which some are toxic and bioaccumulative. Several PFAS can be formed from the atmospheric degradation of precursors such as fluorotelomer alcohols (FTOHs) as well as hydrochlorofluorocarbons (HFCs) and other ozone-depleting chlorofluorocarbon (CFC) replacement compounds. Svalbard ice cores have been shown to provide a valuable record of long-range atmospheric transport of contaminants to the Arctic. This study uses a 12.3 m ice core from the remote Lomonosovfonna ice cap on Svalbard to understand the atmospheric deposition of PFAS in the Arctic. A total of 45 PFAS were targeted, of which 26 were detected, using supercritical fluid chromatography (SFC) tandem mass spectrometry (MS/MS) and ultra-performance liquid chromatography (UPLC) MS/MS. C2 to C11 perfluoroalkyl carboxylic acids (PFCAs) were detected continuously in the ice core and their fluxes ranged from 2.5 to 8200 ng m-2 yr-1 (9.51-16,500 pg L-1). Trifluoroacetic acid (TFA) represented 71 % of the total mass of C2 - C11 PFCAs in the ice core and had increasing temporal trends in deposition. The distribution profile of PFCAs suggested that FTOHs were likely the atmospheric precursor to C8 - C11 PFCAs, whereas C2 - C6 PFCAs had alternative sources, such as HFCs and other CFC replacement compounds. Perfluorooctanesulfonic acid (PFOS) was also widely detected in 82 % of ice core subsections, and its isomer profile (81 % linear) indicated an electrochemical fluorination manufacturing source. Comparisons of PFAS concentrations with a marine aerosol proxy showed that marine aerosols were insignificant for the deposition of PFAS on Lomonosovfonna. Comparisons with a melt proxy showed that TFA and PFOS were mobile during meltwater percolation. This indicates that seasonal snowmelt and runoff from post-industrial accumulation on glaciers could be a significant seasonal source of PFAS to ecosystems in Arctic fjords.

Perfluoroalkyl acids (PFAAs) are highly persistent chemicals that are ubiquitously found in the environment. The atmospheric degradation of precursor compounds has been identified as a source of PFAAs and might be an important pathway for contamination. Lake Vättern is one of Sweden's largest lakes and is an important source for drinking water. In addition to contamination via atmospheric deposition, the lake is subject to several potential contamination sources via surface water inflow. The relevance of different sources is not well understood. A mass balance of selected PFAAs was assembled based on measured concentrations in atmospheric deposition, surface water from streams that constitute the main inflow and outflow, and surface water in the lake. The largest input was seen for trifluoroacetic acid (150 kg/year), perfluoropropanoic acid (1.6 kg/year), perfluorobutanoic acid (4.0 kg/year), and perfluoro-octanoic acid (1.5 kg/year). Both atmospheric deposition and surface water inflow was found to be important input pathways. There was a positive correlation between the input of most perfluoroalkyl carboxylic acids via atmospheric deposition and global radiation and between the input via surface water inflow and catchment area. These findings highlight the importance of atmospheric oxidation of volatile precursor compounds for contamination in surface waters.