Title: Advances in Chemical Exposomics and Toxicokinetics
Speakers: Jonathan Martin, Jiaying Liu
Time: Oct 14th, 2026 (Wednesday) 15:00
Venue: Room 231, New Environmental Building
Inviter: Kun Zhang
Abstract:
Meeting the Challenges of the Chemical Exposome through Advances in Sampling, Sample Preparation and Mass Spectrometry (Jonathan Martin)
Scientists are now forming research synergies to identify the major drivers of disease, motivated by a common understanding that an individual’s environmental exposures are as important as genetics in determining one’s risk of chronic disease and premature mortality. The chemical exposome is the complex mix of chemicals and particle-associated stressors that seep into our body’s cells daily through air, water, food and commercial products. Links between environmental exposures and disease continue to pile up, but the pace of discoveries lags far behind the release of new pollutants to the environment. Chemical exposomics is powered by a set of emerging technologies, workflows, and data science tools that together allow for the complex chemical component of the exposome to be detected and characterized by high-resolution mass spectrometry (HRMS). We can now screen quantitatively for hundreds of priority target analytes and metabolites in a few drops of blood from one individual, while simultaneously scanning tens of thousands of nontarget signals to discover novel or unanticipated exposures. Exposure science is increasingly becoming “personal”, opening great opportunities for precision health research, but chemical exposomics is not yet plug and play. This talk will discuss emerging techniques in chemical exposomics for analysis of human blood and air, the inherent challenges we are still trying to overcome, and the role of new sampling technologies, sample preparation workflows, and advanced hybrid mass spectrometry for uncovering and mapping the chemical exposome throughout the lifecourse of individuals at scale.
Toxicokinetics of Ultraviolet Absorbers Following Exposure via Multiple Routes (Jiaying Liu)
This study investigated the toxicokinetics of five representative ultraviolet absorbers (UVAs) following exposure via multiple routes, with three objectives: (1) to compare toxicokinetic differences among UVAs; (2) to characterize the toxicokinetics of dermal and oral exposure; and (3) to identify biomarkers indicative of exposure routes. The results showed that the elimination half-life (T1/2β) and apparent volume of distribution (Vd) of EHMC were significantly higher following oral exposure than dermal exposure, suggesting greater risk from the oral route. UV-328 showed the strongest bioaccumulation potential, although systemic absorption and tissue distribution were limited for both exposure routes, suggesting pronounced enterohepatic recirculation. Urinary oxidative metabolites of UV-328 were identified as biomarkers of oral exposure to UV-328. Subsequent analysis of 220 human 24-hour urine samples indicated that UV-328 exposure occurred predominantly via non-oral routes. This study provides an innovative approach to accurately assessing internal exposure levels and exposure routes for UVAs.
About the Speakers:
Jonathan Martin is a Professor in the Department of Environmental Science at Stockholm University, Sweden. He heads the Exposure and Effects Unit (ACESx) and serves as Scientific Director of the National Facility for Exposomics at the Science for Life Laboratory (SciLifeLab). His research interests center on chemical exposomics, the identification of environmental contaminants, and the health implications of chemical exposures. His work focuses on developing targeted and nontargeted analytical methods using high-resolution mass spectrometry, integrating toxicology, bioinformatics, and epidemiology to investigate complex chemical mixtures in environmental and human samples. He has published numerous papers in leading international journals, including Environmental Science & Technology (ES&T), Angewandte Chemie International Edition, and Environment International. His contributions have been recognized with the Roy F. Weston Environmental Chemistry Award from the Society of Environmental Toxicology and Chemistry (SETAC) and the Fred Beamish Award from the Canadian Society for Chemistry. He was named a Thomson Reuters Highly Cited Researcher in 2014 and elected to the Royal Society of Canada’s College of New Scholars, Artists and Scientists in 2015. He currently serves as Associate Editor for Environmental Science & Technology Letters.
Jiaying Liu is a Professor in the Department of Nutrition and Health at China Agricultural University. Her research focuses on food safety and environmental health, systematically examining the sources and routes of human exposure, metabolic transformation in the body, and risks associated with early-life exposure. She has published 28 SCI-indexed papers as first or corresponding author in leading environmental health journals, including Environmental Health Perspectives and Environmental Science & Technology. Her findings have been cited by international bodies responsible for setting standards and regulatory limits, including the European Commission, the European Food Safety Authority, and Food Standards Australia New Zealand. In 2023, she was appointed as a toxicology and epidemiology expert for the Joint FAO/WHO Meeting on Pesticide Residues (JMPR). She has led multiple funded research projects, including a project supported by the Excellent Young Scientists Fund of the National Natural Science Foundation of China and projects under China’s National Key R&D Program during the 14th Five-Year Plan.