Department of Cell Toxicology - Sample.  Foto: Dr. Beate Escher

Department of Cell Toxicology


Which chemicals accumulate in biota and in people and what are their effects? We are exposed to thousands of chemicals in our everyday lives. While the level of contaminants has decreased in the past decade, the diversity of chemicals has increased. We have become aware of hazards stemming from emerging chemicals and transformation products. But which chemicals are the culprits? Are there individual chemicals or groups dominating the risk or is it the complex effect of chemical cocktails acting together?

In the Department of Cell Toxicology, we aim to establish a novel risk assessment framework to identify which (groups of) chemicals drive their risk in the environment and for human health. The department’s key objective is to understand the processes that cause adverse effects and to develop in vitro screening tools and predictive models for hazard assessment and as practical monitoring tools.

Our overall goal is to better understand the effects of mixtures of chemicals as they occur in the environment and in our bodies by applying effect-based environmental and human biomonitoring that capture the entire universe of organic chemicals. We develop innovative (passive) sampling techniques to extract complex mixtures of chemicals from all types of environmental media ranging from water, sediment to biota including human tissue and blood. We apply cell-based bioassays, so called bioanalytical tools including modern reporter-gene assays and high-content imaging methods, combined with state-of-the-art target and non-target chemical analysis to characterize complex mixtures. Thanks to our high-throughput facility CITEPro we are able to measure personalized mixtures of thousands of specimens and contribute to elucidating neurodevelopmental, reproductive and immunotoxic effects in human cohort studies.

We specifically focus on mixtures of chemicals, identification of unknowns and transformation products and the role that speciation of organic chemicals plays in their toxicity. We apply mixture toxicity models to link chemical concentrations to effects. We focus on mixture interactions of chemicals at low, environmentally or health-relevant levels and put a specific focus on the so-called “something from nothing mixtures”: if many chemicals are present in the environment and our bodies at concentrations where, on their own, they do not trigger any effects, it is often considered that the mixture is also inactive- our work has contributed to demonstrate that this is not the case, even chemicals below their individual effect threshold may contribute to mixture effects.

We bridge human health and environmental risk assessment by considering common cellular toxicity pathways and develop concepts and test batteries for animal-free testing and chemical hazard assessment. We couple high-throughput screening in cell -based bioassays to quantitative dosimetry in miniaturized assays in 96- and 384-well plate format. Exposure assessment in plate-based assays is a prerequisite for quantitative in vitro to in vivo extrapolations.