Thimo Groffen postdoc researcher FWO

Research Thimo Groffen

Research team

Expertise

I am an environmental scientist with background in biology and environmental toxicology. My research interests focus on biomonitoring of perfluoroalkyl acids (PFAS) in terrestrial and aquatic ecosystems and the environmental and human health risks they pose. Currently, I am investigating the distribution of PFAS in both terrestrial and aquatic environments, and the potential ecological and human health risks related to PFAS pollution. In the terrestrial environment, my main focus is on biomonitoring of PFAS in the terrestrial food chain (soil, invertebrates, plants and songbirds). I am studying factors that affect bioavailability from soil to biota and the potential toxicity related to PFAS accumulation in these organisms. Furthermore, I am developing or optimizing analytical methods to analyze PFAS in different environmental matrices. In the aquatic environment, the main focus of my research is also on biomonitoring PFAS in the food chain, the toxicity of PFAS to aquatic organisms and on factors that might affect PFAS bioavailability. In addition, I am examining different monitoring techniques (i.e. active and passive biomonitoring) in order to investigate their potential for usage in future PFAS research. In my previous research, I developed an analytical method for the analysis of PFAS from multiple abiotic and biotic samples, examined the distribution of PFAS in great tits and invertebrates along a distance gradient from a fluorochemical hotspot, and studied the potential effects of very high PFAS concentrations on reproduction and oxidative status of great tits. My previous studies on the aquatic environment were primarily investigating the PFAS concentrations in aquatic ecosystems in Africa.

TQUAnt: Targeted metabolome and exposome analysis for biological and environmental studies. 01/05/2024 - 30/04/2028

Abstract

How do animals, including humans, and plants cope with stress under altered environmental conditions (e.g., warming, drought), or in the presence of specific contaminants (e.g. PFAS, pesticides) originating from a variety of diverse sources? These are our main running research questions. In this biological/environmental research, it is crucial to trace and quantify different compounds of interest in a broad range of samples ranging from water, soil, and sediments over animal/human- and plant tissues. On the one hand, compounds of interest are hormones, which are well-known signal molecules altered in organisms during stress and being active in a very low concentration range. On the other hand, the ecotoxicological applications require research that keeps pace with the dynamic changes in the new generation of molecules used in industry and the evolution towards raised restriction levels in the environment determined by EU and local governments. Therefore, to claim a worldwide leading position in this field, it is important that we invest in the development of innovative sensitive analytical techniques which allow us to trace and quantify extremely low amounts of different compounds of interest. This project application aims to purchase a sustainable, new generation UPLC-TQD-MS, to improve the analytical platform available. This opportunity will not only support ongoing joint collaborations but will also bring the UAntwerpen to an acknowledged leading position in this field.

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  • Research Project

PFAS analysis of 316 dried samples of invertebrate tissues, fish muscles and seabird feathers. 01/04/2024 - 31/12/2025

Abstract

Some studies of a specific class of chemicals known as per-and polyfluoroalkyl substances (PFAS) have shown they constitute a threat to health and ecosystems. These organic substances have been industrially used over the past 40 years, but are now considered top priority pollutants, due to their chemical persistence, and their pervasive presence in water, food products, animals and even humans. The widespread use of PFAS and their ability to remain intact in the environment means that over time PFAS levels from past and current uses can result in increasing levels of environmental contamination. While the science surrounding potential health effects of bioaccumulation is developing, exposure to some types of PFAS have been associated with serious health effects, thus the possible PFAs impacts on cold and remote environments needs to be further studied. The cold regions (such as the Antarctic Peninsula) are places which are experiencing a continuous increasing pressure caused by different anthropogenic activities. Antarctic animals are key organisms of these ecosystems as potential bio-indicators for the presence of contaminants within this region. To our knowledge, no studies have assessed PFAs bioaccumulation with trophic position through natural aquatic food webs in Antarctica. Particularly, there is a knowledge gap about how certain contaminants may affect Antarctic fauna and associated marine environments, particularly those emerging highly dispersible organic contaminants, such as PFAs, which are highly toxic substances, very persistent, can bioaccumulate in the body and can reach the polar regions by oceanic and/or atmospheric currents: For that reason, they have attracted the attention of the scientific community and regulatory agencies. To fill this knowledge gap, this pioneering study aims to assess the degree of exposure to PFAS in fauna from the Antarctic Peninsula. For this purpose, concentrations of 29 analytes of PFAS will be determined in mammals, seabirds, fishes, and macroinvertebrates. Also, stable isotopes of C and N will be measured to see how spatial and ecological factors influence the bioaccumulation of PFAS, and whether possible interspecific differences are due to habitat contamination or differences in trophic positions. There is an urgent need to develop this project as PFAs levels continue to increase in ecosystems, and little is known about their effects on wildlife and health, especially in Antarctica. The present work may help future research to understand the factors that influence the exposure of Antarctic fauna, and to identify routes of PFAS exposure. Also, it may help to clarify questions about the sources and fate of PFAS in Antarctic ecosystems.

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  • Research Project

Safeguarding Soil with Plants: Exploring Phytoremediation for PFAS Cleanup. 19/02/2024 - 18/02/2028

Abstract

Per- and polyfluoroalkyl substances (PFAS) are synthetic pollutants extensively used in various industrial and consumer products, leading to their widespread presence in the environment and organisms. Given the associated human health risks and significant ecological impact of PFAS contamination in soil, remediation is imperative. However, PFAS exhibit high persistence, posing substantial challenges to effective remediation. Current techniques target only select compounds, are costly, invasive, and lack efficiency in terrestrial environments. Previous studies showed the ability of plants to accumulate PFAS, suggesting phytoextraction as a promising alternative soil remediation method. Yet, knowledge regarding factors influencing plant PFAS uptake remains limited, with current research mainly focusing on single plant species. This project aims to identify general plant characteristics influencing PFAS uptake and optimal soil conditions for such uptake. Furthermore, we will assess the potential of earthworms (Lumbricus terrestris) to enhance the remediation potential of terrestrial plants. These objectives will be pursued through greenhouse experiments and validated by field experiments conducted near diverse PFAS-contaminated sites and under varying climatic conditions. This research will contribute to the understanding of the bioavailability of PFAS in soils to plants and the development of cost-effective and sustainable remediation strategies for PFAS- contaminated soil.

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  • Research Project

European Duckweed Association 01/01/2024 - 31/12/2028

Abstract

The common denominator of the European Duckweed Network is duckweed or Lemnaceae. These small aquatic plants are not only the world's fastest growing flowering plants, they can produce a substantial amount of protein per hectare, considerably in excess of conventional protein crops. Furthermore, they take up nutrients, heavy metals, and nuclear contaminations from heavy polluted wastewater. These are all traits that make duckweed highly suitable to tackle European and global challenges such as food and feed production, bioremediation, or even combinations of both. Thus, duckweed can be a key part of a circular solution to the current sustainability crisis, for example by growing duckweed on pig manure waste, and subsequently using it as pig feed. The European Duckweed Network brings together key research experts from diverse fields such as agriculture, genomics, physiology, space research and nuclear science, and allows knowledge transfer on pilot and large-scale research on duckweed cultivation. Despite the differences in background, all network partners share a common aim, to develop duckweed cultivation for a more sustainable future. It is also recognized by the partners that open communication and knowledge exchange is necessary to achieve this. This way, common challenges such as optimizing harvesting techniques, improved crop protection (against algae, black water lily aphids, and pythium), and reduced plant stress (nutrient imbalances, and climatic conditions) can be systematically tackled, optimally using the multidisciplinary expertise that is present in the network.

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  • Research Project

Award of the Research Board 2023 - Award Verbeure: Applied and Exact Sciences. 01/12/2023 - 31/12/2024

Abstract

The Research Council Prizes of the University of Antwerp are awarded every two years at the expense of the Special Research Fund University of Antwerp. They aim to honor a successful young postdoctoral researcher for a special contribution to his/her scientific field. T. Groffen is a laureate in the exact and applied sciences (Prize Frans Verbeure).

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  • Research Project

Effects of the chemical structure of per- and polyfluoroalkyl substances (PFAS) on the bioaccumulation and toxicity to terrestrial and aquatic plants and invertebrates. 01/10/2023 - 30/09/2026

Abstract

Per- and polyfluoroalkyl substances (PFAS) are synthetic organic compounds that have unique properties which have led to a widespread industrial and commercial use, and subsequent contamination of the environment. The partitioning of PFAS to the abiotic matrices, which are important exposure routes for PFAS in the food chain, depends on chemical-, media- and site-specific characteristics. Organisms residing in polluted ecosystems may accumulate different PFAS depending on their physiological and structural characteristics, and on the bioavailability of PFAS (affected by among others their chemical structure). Quantitative measurements of bioaccumulation are well known for legacy PFAS, but not for the vast majority. Similarly, the relative lack of toxicological data for most PFAS is an uncertainty factor in ecological risk assessment (ERA). The objective of this study is to investigate how the chemical structure of PFAS affect their bioaccumulation and toxicity in aquatic and terrestrial organisms. We will use a focused comparative testing (i.e. including PFOS and PFOA, for which such information on bioaccumulation and toxicity is present), in a phylogenetically broad range of organisms to provide baseline data for ERA. A probabilistic risk assessment approach using species sensitivity distributions will be used to investigate the chronic and acute toxicity of fifteen PFAS and to estimate toxicity benchmark concentrations for soil, sediment, and freshwater.

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  • Research Project

Research on PFAS contamination in the food chain (PFASFORWARD 1). 01/09/2023 - 31/08/2027

Abstract

The main objective of PFASFORWARD is to gain insights concerning the presence, prevalence, behaviour, and distribution of various per- and polyfluoroalkyl substances (PFAS) throughout the entire food chain, including the impact of processing. The pathways by which PFAS can enter the feed and food chain will also be investigated. PFASFORWARD will focus on the PFAS listed by Commission Recommendation (EU) 2022/14311, mainly 4-EFSA-PFAS, carboxylate-PFAS (C5-C14), sulfonate-PFAS (C4-C13), and PFAS substitutes (DONA, F53B minor and major and HFPO-DA). Furthermore, untargeted analyses will also be performed for a limited number of samples to extend the analyte scope and envisage a broader range of fluorinated contaminants. Firstly, the monitoring data obtained within FLUOREX will be further complemented by adding matrices from the market. Afterwards, PFAS behaviour and distribution will be investigated by analyzing different highly contaminated edible fractions of the same animal (including fish, pig, cattle and chicken) or plant (including apples, potatoes, carrots, and cauliflower). Since the concentrations of PFAS can vary between the different parts, the impact of processing (e.g. grain milling, juice pressing, production of meat and dairy products) will be investigated. It should also be taken into account that this might be influenced by the type of PFAS (e.g. long-chain versus short-chain compounds). Additionally, more knowledge on the origin and transfer of PFAS throughout the food chain will be obtained through literature review, experiments or simulations in order to be able to reduce or prevent possible contamination and, as such, guarantee consumers' food safety. Information on possible PFAS transfer from compost, sewage sludge, irrigation water, well water, soil, feed and feed materials will be gathered. PFASFORWARD will not only give an overview of the presence of PFAS on the Belgian market but also respond to issues highlighted in the Commission Recommendation (EU) 2022/1431 on PFAS monitoring in food.

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  • Research Project

Center of Expertise Environment and Health (2022-2027) 01/12/2022 - 30/11/2027

Abstract

This policy-oriented scientific research generates new human biomonitoring data and data from environmental measurements to examine to what extent and how adolescents in Flanders are exposed to environmental pressure and what this exposure does to the body. The study design is interdisciplinary. All Flemish universities, VITO, PIH and INBO contribute; VITO is the research coordinator. In this configuration, CRESC takes the lead of the social sciences aspects, including the research of socio-stratification in participation rates and study results, of risk perception, risk communication and stakeholder involvement in the study.

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  • Research Project

Partnership for the Assessment of Risks from Chemicals (PARC). 01/05/2022 - 30/04/2029

Abstract

Chemicals risk assessors and managers are faced with data and knowledge gaps and lack of tools and methods, to speed up and prioritise risk assessments and capture risks from existing and emerging substances across regulatory domains. The lack of available or accessible information increases the risk of 'regrettable' substitutions and slows down the design of safer chemicals. A diverse landscape of regulatory frameworks and actors carrying out risk assessment of chemicals for their specific purpose has resulted in a fragmented approach. Risks to human and environmental health are still in certain cases considered separately, while in most cases they are inherently interrelated. To enable risk assessors and risk managers to respond to current and future challenges, the Partnership should stimulate research and innovation in chemicals risk assessment by developing a collaborative network with public research entities. A common research and innovation programme should be established by national and EU risk assessors and risk managers in consultation with relevant stakeholders (academia, industry, associations and others). Activities of the Partnership should be complementary and subsidiary to obligations under existing regulatory frameworks, and should coordinate with these as relevant. The Partnership should become a reference centre for research questions related to chemicals risk assessment, including those emerging from other Horizon Europe partnerships or missions. The Partnership is expected to establish relevant collaborations with other Horizon Europe partnerships and missions as set out in the working document on 'Coherence and Synergies of candidate European partnerships under Horizon Europe' as well as to explore collaborations with other relevant activities at EU and international level. The Partnership should align with EU-wide initiatives on open access and FAIR data.

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  • Research Project

Analysis of a series of Crab samples from Ecuador for PFAS content. 17/11/2023 - 31/12/2023

Abstract

Extraction and analysis of muscle tissue of crabs, coming from the Guayas estuary in Ecuador, for the determination of concentrations of 29 PFAS. The extraction consists of solvent extraction, followed by clean-up with activated carbon powder and filtration. Hereafter samples were analyzed using UPLC-MS/MS.

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  • Research Project

Analysis of the impact of input of drainage water into the city pond. 01/05/2023 - 31/05/2024

Abstract

The pond in the Stadspark in Antwerp suffered particularly badly from the various drainage operations in the area over the past decade, and even dried up at certain times. Moreover, the park is very centrally located in a very densely populated neighbourhood, and is one of the few green areas in the wider area. Both the attractiveness of the park, the health of fauna and flora, and its cooling effect on the immediate surroundings are largely dependent on the presence of water features. So using the drainage water from the Den Bel buildings would be a good solution to combat the desiccation of the city park pond. However, from the summer of 2021, the re-infiltration project became severely hypothecated by the finding that PFAS were present in the Den Bell drainage water. PFAS or per- and polyfluoro alkyl substances are anthropogenic polymers based carbon-fluorine compounds that are particularly persistent, can accumulate strongly in biota and are potentially toxic. The aim of this study is to investigate the distribution and bioavailability of PFAS in the city pond before and after the discharge of the drainage water. In addition, the effects on biological water quality will be investigated. Finally, the potential of PFAS removal through phytoremediation will be investigated.

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  • Research Project

PFAS analysis in fish samples 01/12/2022 - 31/01/2023

Abstract

PFAS worden al sinds de jaren '60 van vorige eeuw geproduceerd; Doordat een aantal componenten, zoals PFOS en PFOA, niet meer geproduceerd worden, is er een verschuiving in de samenstelling van PFAS in visweefsel over de laatste 20 jaar te verwachten. in deze studie worden analyses uitgevoerd van PFAS in palingweefsel dat bewaard werd door het INBO. Op die manier moet het mogelijk zijn om trends in de accumulatie na te gaan.

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  • Research Project

Setting safe limits for two short-chained perfluoroalkyl substances for experimentally exposed soil organisms: perfluorobutane sulfonate (PFBS) and its by-product perfluorobutane sulfonamide (FBSA). 01/04/2022 - 31/03/2023

Abstract

The scientific and public attention to the group of per- and polyfluoroalkyl substances (PFAS) has risen exponentially since the beginning of the 2000s. These chemicals have been produced since the 1940 in large quantities for numerous applications such as firefighting foams and fast-food packaging. Due to their production and use in several consumer products, PFAS have been distributed globally in the environment, in which they accumulate in organisms. Regulatory measures for legacy long-chained PFAS, such as perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) have led to a restriction in their production and use, with some exemptions. Nonetheless, these long-chained PFAS have often been replaced by short-chained homologues, such as perfluorobutane sulfonate (PFBS). This is also the case for 3M Zwijndrecht, Belgium, a known PFAS hotspot. As a byproduct in the production of PFBS, perfluorobutane sulfonamide (FBSA) is produced. Both chemicals are not regulated, due to the lack of data on their toxicity. As a consequence, both chemicals can be produced and used unrestrictedly, and both of them are discharged in the environment. Based on their persistency (they do not or merely break down in the environment), because they first adsorb to solid matrices after being discharged, and because it is assumed that they are equally toxic as their long-chained homologues, it is necessary to investigate the toxicity of these chemicals to soil organisms. This allows us to set safe limits to protect soil ecosystems. The objective of this study is to set such safe limits for soil ecosystems based on species sensitivity distributions.

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  • Research Project

Influence of soil properties on the sorption of per- and polyfluoroalkylated substances to soil and the bioavailability and bioaccumulation to terrestrial biota. 01/10/2020 - 30/09/2023

Abstract

Per- and polyfluoralkylated substances or PFAS, which have been used in large quantities since the 1940s because of their applications such as food packaging, are receiving increasing attention since the early 2000s. The production and use of PFAS have led to the global detection in the environment. Despite regulatory measures for perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA), the most frequently detected PFAS, there are concerns on many other PFAS that are similar in structure and properties and that are not regulated. Soils form the basis of the terrestrial food chain and PFAS uptake from contaminated soils is known to cause human exposure to PFAS. However, there are many uncertainties on the behaviour of PFAS in soils and the following bioavailability to and bioaccumulation in biota. The general objective of my project is to investigate the role of soil properties and temperature on the uptake and distribution of PFAS in the terrestrial food chain. Descriptive studies, close to a fluorochemical plant, will provide us with an overview of the concentrations of legacy, novel and unknown PFAS in the terrestrial food chain and how these concentrations are influenced by soil properties. In addition, experimental studies will be performed to disentangle causal links from confounding effects, but also to study the uptake and effects in terrestrial invertebrates and plants. This study will help policy makers to set new, or alter existing, PFAS criteria for soil.

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  • Research Project