Bio: Research Director at the Division of Climate and Environmental Health at the Norwegian Institute of Public Health (NIPH), Professor in human toxicology at the University of Oslo, and Co-Editor in Chief for the scientific journal Environmental Research. Professor Øvrevik had more than 20 years’ experience in research, risk assessment, and guideline and policy development in toxicology and environmental health. His research activities have centred around the cellular and molecular mechanism driving in toxicity of inhaled pollutants in vitro, with a main focus on the importance of physical and chemical characteristics of particles for adverse health effects.

Abstract: Particles and fibers, whether process-derived, engineered, or environmental, have the possibility to cause adverse health effects. Coal, silica, and asbestos, historic particulates, clearly were associated with human disease inducing a human health burden. The scientific evaluation of historic exposures set the stage for conducting air pollution/particulate matter research demonstrating that adverse health outcomes from particulates created potential risk for the general population. Research emerged that adverse effects were not confined to the primary target site (e.g., lung) but also included cardiovascular, neurological, and developmental dysfunction. The evaluation of particulate matter quickly adapted to the rapid expansion of engineered nanomaterials. These studies expanded our knowledge of physicochemical characteristics (e.g., shape, surface area, solubility) and impact on toxicity, and the role of particles as carriers of other harmful components (e.g. the Trojan Horse Effect). However, the study of novel engineered nanomaterials required a transition to preventative measures when interpreting controlled toxicity evaluations. The same can now be applied to micro- and nanoplastics. Shifting the paradigm of particulate toxicology from explaining a chronic disease to intervening prior to a health burden brings many challenges to toxicologic research and exposure science. Challenges include choice of exposure doses, physicochemical characterization, toxicologic research proceeding without exposure science guidance, and epidemiological investigations without post-exposure timepoints sufficient for evaluating potential induction of chronic disease. This talk will provide the foundation of the session by illustrating advancements in understanding mechanisms of toxicity and challenges of toxicity interpretations without a known health burden.