My research is focused on understanding the emissions and chemical transformation of volatile organic compounds (VOCs) in Earth's atmosphere. Specifically, I evaluate and quantify anthropogenic and natural emissions that lead to the formation of hazardous pollutants, such as ozone and secondary organic aerosol. I measure VOCs using a state-of-the-art proton-transfer-reaction mass spectrometer, which we deploy on aircraft and mobile laboratories to measure emissions from various sources. So far, we've targeted emissions from wildfire plumes, concentrated animal feed lots, oil and natural gas development, vehicle tailpipes, populated urban centers, and forested regions of the Western U.S.
My research is primarily focused on understanding sources of air pollution. Currently, I am studying the emissions from two understudied (and very different) sources of pollution - wildfires and volatile chemical products (also known as consumer products).
Wildfires are a major source of particulate matter and volatile organic compounds (VOCs) to earth's atmosphere. In the Western United states, the frequency and intensity of wildfires has increased, leading to higher incidents of hazardous air pollution in populated urban areas during the summer months. Since 2016, our lab has been studying the chemical complexity of wildfire emissions with an aim of understanding how these emissions lead to the formation of ozone and PM, which are criterion pollutants that impact human health. In summer 2019, we will participate in the FIREX-AQ field campaign to characterize wildfire VOCs. We will deploy our mass spectrometer onboard the NASA DC-8 aircraft and sample smoke in and around large wildfire plumes to understand how much these emissions impact downwind air quality.
In the grand scale of urban air quality, wildfires represent a large, seasonal source of pollution. However, urban air quality can be a year-round issue and it is influenced by every day human activities. For decades, vehicles emissions were the dominant source of air pollution. However, regulations and improvements in technology have drastically reduced vehicle pollution - in Los Angeles, for example, VOCs emitted from vehicle tailpipes have decreased by a factor of 100 from their 1960s levels. Air in LA is much cleaner than it used to be, but there are still days in which air quality indices exceed acceptable healthy levels. Recent work has shown that, today, emissions from consumer products (e.g. personal care products, paints, and cleaners) are just as likely to contribute to urban air pollution as vehicle tailpipe emissions. We’ve found, for example, that evaporation of deodorant and hair care products can lead to VOC emissions that are comparable to regional emission rates of certain pollutants from vehicle tailpipes.
Little is known about these emissions and how the lead to ozone and PM pollution. In 2018, we deployed out mass spectrometer on a mobile laboratory to measure consumer product emissions in densely populated regions of the U.S. We are currently sifting through this data to understand the extent to which these “volatile chemical products” contribute to urban air pollution in cities such as such as New York, Chicago, and Denver.
Honors and Awards
- CIRES Visiting Fellowship
- CO-LABS Governer's Award for High Impact Research (Honorable Mention)