Chemical Exposures: Novel Approaches for the Identification of Toxic Organic Chemicals in Complex Mixtures 

Carsten Prasse
Environmental Health and Engineering
Johns Hopkins University

ABSTRACT:  Exposures to anthropogenic chemicals are a key contributor to the human “exposome”, or the sum of environmental stressors that shape and determine health outcomes. In addition to more 85,000 chemicals in commercial use today, we are exposed to thousands of chemicals formed when anthropogenic and natural organic compounds degrade in the environment and/or engineered systems. Frequently it is exposure to a complex mixture of chemicals that results in additive, adverse health effects. However, engineered systems for human and environmental health protection–like drinking water and wastewater treatment–rely on chemical-by-chemical assessments and regulations that rarely consider complex mixtures. Moreover, approaches that help prioritize identification and treatment of the most toxic chemicals are widely missing. As a result, adverse environmental and human health outcomes, unintended consequences of engineered treatment solutions, and inadequate regulations only become evident years after populations have been exposed. If we want to address this issue, we need to develop approaches that help us identify those chemicals that are of highest concern for human health and the environment. In this seminar, I will discuss the development and application of a novel analytical approach, called reactivity-directed analysis (RDA), which can be used to identify and prioritize those compounds that are of particular health concern. RDA combines approaches from analytical chemistry, molecular toxicology, data science, and environmental engineering to detect and identify toxic organic electrophiles, the largest class of known toxicants. RDA provides a new framework for identifying toxic byproducts and their precursors that can be used to optimize engineered treatment systems and minimize risks from toxic byproducts.

BIO:  Carsten Prasse, PhD is an Assistant Professor in the Department of Environmental Health and Engineering in the Johns Hopkins Whitening School of Engineering and the Bloomberg School of Public Health. Carsten received his Master’s degree in Environmental Sciences from the University of Bayreuth, Germany in 2008. In 2012 he obtained his PhD in Chemistry at the Federal Institute of Hydrology in Koblenz, Germany, under the guidance of Dr. Thomas Ternes for which he was honored with the dissertation award of the German Water Chemistry Society. After completing postdoctoral work at the Federal Institute of Hydrology and the University of California at Berkeley (research group of Dr. David Sedlak), he joined Johns Hopkins University in 2018.