Going Beyond Single-Chemical Risk Assessment

Wednesday, September 20, 2017 12:10:00 PM - Wednesday, September 20, 2017 2:00:00 PM
Rm. SS 1069, Sidney Smith Building, 100 St. George Street
Environment Seminar

HUI PENG, Assistant Professor, Department of Chemistry and School of the Environment, University of Toronto

ABSTRACT: A growing number of chemicals are being introduced into the commercial realm, and the Toxic Substances Control Act has been estimated to cover over 75,000 unique chemicals. Assessing the risks posed by each of these chemicals overwhelms traditional single-chemical risk assessment strategies. This task is further complicated with real environmental mixtures which may contain numerous, previously unknown, chemicals. Moreover, there is increasing evidence showing that previously unknown chemicals may be more important — in terms of abundances or toxicities — than currently regulated or known chemicals; targeted regulation of known chemicals may underestimate the risks posed by exposure to environmental mixtures. Recent developments of high-resolution mass spectrometry provide a chance to address these challenges by developing untargeted chemical analysis methods. With this strategy, thousands of previously unknown environmental chemicals were tentatively identified in the environment with some of the chemicals showing higher abundances or stronger toxicities than classic well-known chemicals. These results confirmed the existence of numerous previously unknown chemicals in the environment, and provide a new strategy to assess the exposure risks of environmental mixtures in an unbiased fashion. Despite this progress, how to efficiently use the large datasets produced by these high-throughput methods to go beyond classic single-chemical strategy analysis, and to address the reality of environmental mixtures, has yet to be answered.

BRIEF BIO: Prof. Peng is a new faculty member starting his independent research career in the Department of Chemistry and the School of the Environment, at the University of Toronto. Trained as an environmental scientist, Dr. Peng’s research is in the fields of environmental chemistry and toxicology, with a focus on determining the environmental occurrence of pollutants and their potential health and ecological risks. His current focal interest is in the development of novel chemistry and biology techniques to pursue three research directions: untargeted identification of novel environmental chemicals; investigation of sources and behaviors of environmental chemicals; and unbiased identification of protein targets by chemical proteomics.