Chemistry for Environment & Health and Environmental Health & Toxicology have three main research themes
1 – Exposure assessment of legacy pollutants and chemicals of emerging concern
Several hundred million tonnes of man-made chemicals are commercially used in Europe that potentially threaten human health and the environment. E&H concentrates on the development of high-end analytical techniques to increase the power to detect and identify chemicals including compounds not previously identified in the outdoor environment (e.g. water, sediment, biota), the indoor environment (e.g. air, house dust, consumer products) and in human materials (e.g. cord blood). For this, we use suspect screening and non-target analysis with high-end chromatographic techniques coupled to high resolution mass spectrometry and combine these with multivariate statistics to further elucidate the chemicals of concern.
We investigate the occurrence and fate of emerging substances, such as flame retardants, plasticizers, endocrine disruptors, organofluorine compounds (PFAS), and microplastics. E&H is also developing methods to detect and quantify microplastics in human matrices (e.g. blood, placenta), and elucidate the potential human health effects of the microplastics. We also work on the analysis of highly complex chemical mixtures (UVCBs, substances of unknown or variable composition, complex reaction products or biological materials), such as chlorinated paraffins or petroleum hydrocarbons, and develop analytical methods (e.g. GCxGC or LCxLC) combined with high resolution mass spectrometry to study the occurrence and fate of these complex mixtures. We also use and develop effect-directed analysis (EDA) approaches by developing high resolution fractionation techniques to reduce the complexity of the chemical mixtures, coupled with toxicological screening assays.
We are developing analytical methodologies to measure and identify (micro)plastic contamination in environmental matrices, and assess the risks of plastics and microplastics to the environment.
Another focal point, as part of the circular economy, is the development of analytical methods to detect, identify and quantify toxic additives in plastic products, plastic waste and recycling streams. In this respect we develop fast screening techniques (direct-probe, AP-MALDI, direct injection) to detect and identify chemicals that are present, emitted or leached from consumer products. This provides information on which chemicals are of concern for human health, and it sheds light on the relationship between indoor exposure levels, consumer products and building materials.
2 – Toxicological hazard characterization
E&H performs toxicological hazard characterization through toxicity profiling and studies on toxicological mechanisms. We do this with pure chemicals as well as human and environmental samples. In line with contemporary toxicological hazard and risk assessment practice, we strive to investigate the toxic actions of chemicals using predominantly in vitro, cell-based assays and zebrafish embryo models. Zebrafish embryos enable us to study toxicity within a whole organism linking toxic mechanism to health outcomes. Our toxicological focus is mainly on endocrine, metabolic and neurological endpoints.
To investigate perturbations of these endpoints, we use molecular techniques e.g. knock-out models, reporter-gene assays, in situ hybridisation, qPCR, behavioural tests and metabolomics and lipidomics techniques. The gained mechanistic knowledge is applied to develop novel and/or improve existing in vitro bioassays that are either high-content (i.e. low throughput, but with high information potential) or high-throughput (i.e. the potential to rapidly screen many chemicals and mixtures for potential effect on a specific endpoint). In addition, this toxicological information can be used to substantiate mechanistic descriptions of toxicological health outcomes, or adverse outcome pathways (AOPs). E&H has developed several assays to asses toxicity of endocrine disrupting chemicals (EDCs)EDCs, such as bioassays for thyroid hormone transport, steroid hormone synthesis, oocyte development and (zebrafish) embryotoxicity.
In addition, the E&H bioassays are being used to screen for potentially harmful compounds in a wide variety of matrices, such as house dust, drinking water, human breast milk, meconium and placenta. To date, relatively little is known about the risk of these chemicals in/via these matrices, especially for the newer chemicals that are in our living environment. The effect-directed analysis (EDA) approach that is implemented at the department, where chemical fractionation of the sample is coupled with high-throughput toxicological hazard assessment, clearly addresses a scientific and societal need for risk assessment of mixtures of unknown constituents for humans and the environment
3 – Linking life-style factors (including chemical exposures) to human health indices
It is becoming increasingly clear that especially children in the womb and young children are particularly vulnerable for adverse health effects as a result of chemical exposures. The E&H department has established a mother-child cohort called LINC. This cohort provides the opportunity to measure chemical exposures during early life in urine, (cord) blood and placenta and link these early-life exposures to development and behaviour of children. Linking human exposure data to information on sources of chemicals and epidemiological surveys, for instance our LINC cohort, enables us to investigate exposure-response relationships. E&H contributes to human biomonitoring andunravelling the chemical exposome focusing on the assessment of exposure through the measurement of chemicals, their metabolites or specific health markers in human body fluids and tissues. To accelerate the development of human biomonitoring the use of alternative methods for the determination of exposure, e.g. wearable wristbands, house dust, and handwipes for sampling individual environment of people, is explored. In addition to chemical exposures, also other life style factors, such as obesity, are being investigated as modulators for health outcomes in human populations. The knowledge from linking chemical exposures and lifestyle factors with human health indices can provide crucial information and guidance for strategies to prevent adverse health effects for regulators and society as a whole.