Research Raewyn Town

Abstract

Reliable assessment of the ecological risks posed by chemicals is a fundamental component of European policies concerned with safe use of chemicals e.g. REACh, The Green Deal, and protection of ecosystem functioning and ecosystem services (Water Framework Directive). Chemical risk assessment typically involves extrapolation of effects observed in-vitro and in-vivo under laboratory conditions to predictions of effects at the ecosystem level. This is a very challenging task and current extrapolation models have limitations, notably due to a number of ecological processes that are disregarded by the models and the paucity of data for parameterisation and validation. QTOX will develop mechanistic knowledge and data efficient modelling tools to bridge the gap between standard toxicity data (typically acute effects ofsingle chemicals) and ecologically relevant end points arising from chronic, time variable exposuresto chemical mixtures. The results will be achieved through an interdisciplinary and intersectoral research and training program in which 10 doctoral candidates will characterise the mechanistic processes describing the successive eventsfrom exposure to ecosystem-level effects and develop models for extrapolation of adverse effects acrosslevels of biological organisation under environmentally realistic conditions. Notably, the effects of chemical mixtures, dynamic exposure conditions and their interaction with climate change scenarios will be characterised in a series of mesocosm experiments at three sites in central and southern Europe. The mesocosm work will serve as a uniting training element and a rich source of data for testing and validating the modelling framework. QTOX will produce an open access toolbox for quantitative extrapolations in ecotoxicology and a cohort of researchers equipped with the knowledge and skills necessary to implement and develop rigorous approaches for predicting adverse effects of chemicals.

Researcher(s)

• Promoter: Blust Ronny
• Co-promoter: De Boeck Gudrun
• Co-promoter: Town Raewyn
• Fellow: Bhatkhande Apurva
• Fellow: Farooq Sadiya

Research team(s)

• Ecosphere

Project website

Project type(s)

• Research Project

Abstract

Plastic pollution is defined as ubiquitous in the aquatic environment which has induced a strong research effort the past decade notably on methods development to analyse items within the size range smaller than 5mm known as microplastics (MPs). However, small microplastic (< 10 µm) and nanoplastics (NPs; < 1 µm) which are also found in the environment are less investigated notably because of sampling and analytical limitations. It thus induced a knowledge gap in the plastic research as well to assess their concentration and distribution in the environment as to describe their effect in the estuarine and marine ecosystems. Nevertheless, this lack of relevant and standardized method(s) determination is associated to a difficulty to build environmental risk assessment. The main objectives of this project is to develop an innovative methodological strategies toolbox for small MPs and NPs analysis in complex environmental matrices including information on physical and chemical characteristics as well as their fate in the environment such as aggregation features, degradation kinetics and additives release kinetics that might be thus integrated in a biochemodynamical model to increase knowledge on plastic particles with size < 10 µm.

Researcher(s)

• Promoter: Blust Ronny
• Co-promoter: Town Raewyn
• Fellow: Falcou Préfol Mathilde

Research team(s)

• Ecosphere

Project type(s)

• Research Project

Abstract

Wastewater analysis of drugs and their metabolites can provide information on drug use and abuse in general populations. Conventionally, 24 h composite samples are analyzed and the chemical reactivity of the compounds within the wastewater matrix is ignored. In practice, these compounds are likely to associate with the diverse particles present in the wastewater matrix. Negligence of such interactions will lead to erroneous estimations of analyte concentrations. To address this issue, this project employs innovative active-passive sampling (APS) strategies to quantify psychoactive substances in wastewater, taking into account their chemodynamic behaviour. The interpretation framework will be supported by determination of analyte-particle interactions with a range of particles. The APS device incorporates a controlled hydrodynamic flow of the sample matrix across selective sorbents which accumulate the target compounds. APS can be used in equilibrium mode to estimate the equilibrium analyte concentrations, e.g., the freely dissolved form; and in non-equilibrium mode to provide information on the kinetic features of their chemical forms in wastewater matrices. The performance of the APS will be compared with conventional 24 h composite sampling in both influent and effluent flows of wastewater treatment plants. A novel passive dosing strategy will also be explored for the ecotoxicological risk assessment of the drugs and their metabolites via a battery of toxicological tests.

Researcher(s)

• Promoter: Blust Ronny
• Co-promoter: Town Raewyn
• Fellow: Anies Allen Jun

Research team(s)

• Ecosphere

Project type(s)

• Research Project

Abstract

Plastic particles are everywhere in the environment and there is concern about the adverse effects they may have on organisms, and subsequently on ecosystems. Much global attention has been directed towards so-called microplastics, i.e. plastic particles with dimensions in the millimeter to micrometer range. Microplastics slowly degrade in the environment, by physical and chemical processes, into smaller and smaller entities, eventually reaching the nano-size domain. Due to difficulties in sampling and characterisation, almost nothing is known about the amounts and behaviour of extremely small plastic particles with dimensions on the order of nanometers, i.e. nanoplastics. Our project addresses this knowledge gap. We will measure and model the chemical reactivity, biouptake, and bioaccumulation of nanoplastics and their adverse effects on aquatic organisms. The results will provide fundamental information which enable robust risk assessment strategies to be developed that inform environmental policies.

Researcher(s)

• Promoter: Blust Ronny
• Co-promoter: Town Raewyn

Research team(s)

• Ecosphere

Project type(s)

• Research Project

Abstract

The present project aims at developing innovative analytical and sampling approaches to estimate the (ab)use of illicit drugs and psychoactive pharmaceuticals, e.g. antidepressants, antipsychotics, benzodiazepines, and opioids in the general population. The analysis of human excretion products of substance use in wastewater has the unique properties to deliver such data. The overarching objective is to validate innovative active-passive sampling (APS) and detection strategies for biomarkers of illicit drugs and psychoactive pharmaceuticals to be used for the long-term monitoring of substance use in communities. The hypothesis to be tested is if APS will provide a more convenient sampling strategy compared to daily 24-h composite sampling. We will first develop analytical assays to measure biomarkers of psychoactive pharmaceuticals and drugs in wastewater. Then we will develop APS strategies for the target analytes in influent and effluent wastewater and will investigate the advantages/limitations of the APS strategies in real-life conditions. These new sampling strategies will be compared to the conventional 24-h composite sampling. We will plan sampling campaigns in 5 Slovene and 3 Belgian cities to: estimate for the first time community-wide psychoactive substance use in the Slovene and Belgian cities; evaluate chemical removal efficiencies for the wastewater treatment plants; investigate the utility of APS for improved identification of new psychoactive substances.

Researcher(s)

• Promoter: Covaci Adrian
• Co-promoter: Blust Ronny
• Co-promoter: Town Raewyn
• Co-promoter: van Nuijs Alexander

Research team(s)

• Toxicological Centre

Project type(s)

• Research Project