Exploring the Great Unknown: New Tools to Assess Complex Environmental Mixtures

Shane A. Snyder, Professor – Civil & Environmental Engineering
Executive Director – Nanyang Environment & Water Research Institute (NEWRI)
Nanyang Technological University (NTU)
Singapore

Everyday the human body is exposed to an unphathomable number of endogenous and exogenous chemicals. The wholistic view of characterizing human exposure has been called the exposome. Synthetic chemicals were not part of the human experience until the late 19th century with the accidental discovery of the synthetic dye, mauve. Today, more than 65 million chemicals are commercially available, many of which enter the environment both knowingly and unknowingly. From a drinking water exposure standpoint, not only are the chemicals themselves a potential risk, but also the innumerable transformation products formed during water treatment processes. Historically, analytical techniques to measure trace levels of environmental pollutants were time-consuming, labour-intensive, and technically-sophisticated. New techniques are rapidly evolving to measure ultra-trace levels of chemicals with automated and/or minimum sample preparation and detection by tandem and/or high-resolution mass spectrometry. Monitoring indicator compounds that provide specific information regarding watershed contamination and treatment process efficacy by high-resolution quadrupole mass spectrometry (QTOF) coupled to both GC and LC interfaces provides both targeted analytic information while simultaneously acquiring full mass spectra that allows a more comprehensive view of the complex chemical mixtures and results transformation products in water. Inductively-coupled plasma mass spectrometry (ICP/MS), which can be interfaced with GC and LC to provide atomic composition information, effectively screens for potentially toxic iodinated and brominated disinfection byproducts reesulting from chlorination of water. Coupled with high-throughput bioassays, these techniques provide a new view as to the complex mixtures occuring in the environment and their potential impacts to health. However, these techniques are applicable beyond environmental pollution monitoring. This presentation will also show for the first time the application of bioeffects directed analyses for the discovery of novel environmental substances recently discovered to prevent asthma in humans. Modern analytical platforms coupled with advanced genomics tools provides a never before realized workflow that can be as readily applied to environmental contaminant characterization as it can to potential cures for human disease. This presentation will demonstrate some of the latest findings and provide a view for the future of addressing the unknown world of chemical mixtures.