Title: Microbial Volatile Organic Compounds and a Multidimensional Framework for Indoor and Outdoor Air Quality
Abstract:
Microorganisms emit hundreds of volatile organic compounds (mVOCs) that serve as chemical signals and metabolic byproducts, yet their contribution to the air we breathe remains poorly constrained because they occur at low levels within complex mixtures. This seminar presents real-time measurements with sub-second resolution and sub-part-per-trillion sensitivity that resolve mVOC responses to microbial taxa, growth phase, substrate, humidity and light. Controlled experiments with environmental bacteria and fungi reveal more than 400 compounds that vary with species and life stage. In damp carpet, dust and drywall, microbial compounds can dominate odor even when non-microbial compounds dominate abundance. Light exposure rapidly shifts fungal emissions of isoprene and other mVOCs without changing total VOC levels, offering a route to detecting active fungi indoors. These findings motivate a multidimensional framework that evaluates abundance, atmospheric reactivity, toxicity, and odor activity (ARTO) rather than concentration alone. Applied to wildfires, fossil fuel extraction, battery gases and volatile chemical products across Texas and California, the ARTO framework shows that sources contributing little to total VOC abundance can dominate odor or toxicity impacts on communities. Emerging directions connecting microbial, environmental and human volatilomes are also discussed.
Bio:
Dr. Pawel Misztal is an Associate Professor in the Maseeh Department of Civil, Architectural and Environmental Engineering at the University of Texas at Austin, where he holds the Cockrell Family Fellowship. He also holds a courtesy appointment in the Department of Psychology. He leads the Misztal “Sniffer” Lab, which focuses on atmospheric chemistry, air quality, and factors affecting human health through advanced mass spectrometry techniques. Dr. Misztal has over 15 years of experience in real-time measurements of volatile organic compounds (VOCs) using proton transfer reaction time-of-flight mass spectrometry (PTR-TOF-MS) and other techniques. His research spans microbial volatile organic compounds (mVOCs) in indoor and natural environments, outdoor and indoor air quality, wildfire emissions, fossil fuel sector impacts, battery safety and thermal runaway detection, human volatilome characterization, and environmental health applications. Prior to joining UT Austin, Dr. Misztal was a research specialist in the Department of Environmental Science, Policy, and Management at UC Berkeley, where he quantified mVOC emission factors from bacteria and fungi in the Sloan Microbiology of the Built Environment program and led the first direct regional airborne VOC emission measurements in California to evaluate air quality models for the California Air Resources Board. He has authored over 75 peer-reviewed publications in leading journals including Nature, Science, Environmental Science & Technology, and Proceedings of the National Academy of Sciences. Recent work includes demonstrating how lighting influences mVOC emissions from fungi in house dust, developing ultrasensitive direct chemical analysis of human hair for exposure profiling, characterizing air pollution from unconventional sources, and addressing battery safety for next-generation energy storage systems. Dr. Misztal is a recipient of the NSF CAREER award and his research is supported by NSF, DOE, NOAA, ARPA-E, DHS, HEI Energy, AQRP, UCSD, Spiegel Family Fund, and the A.P. Sloan Foundation. He received the AEESP Award for Outstanding Teaching in Environmental Engineering & Science in 2024 and was recognized as one of Texas 10 Most Inspiring Professors in 2022 by The Alcalde.