Behavior and Quantification of Airborne Pollutants
I study air pollutants that are classified as semi-volatile. This means that they can enter the atmosphere where it is warm, travel long distances with the winds, and then deposit back to earth surfaces where it is cold. Many of the semi-volatile pollutants are problematic because they are both long-lived and toxic to humans and wildlife
Many of the commonly used pesticides, as well as flame retardants and other industrial compounds, fall into this category. Due to their ability to travel long distances through the atmosphere, these chemicals have been found in high mountains and in the Arctic—far from where they are used or produced.
My research group uses air sampling and gas chromatography to determine the concentrations of semi-volatile pollutants in air at various locations. We measure their concentrations near sources, such as agricultural fields, to determine the degree to which different semi-volatile pollutants enter the atmosphere and measure their concentrations in remote alpine and arctic areas to determine how far they travel through the atmosphere.
We conduct chemical fate modelling to predict the behavior of these chemicals under different environmental conditions, such as change in temperature, humidity, and wind speed, and conduct field studies and modelling to determine how long semi-volatile pesticides remain on leaves before entering the atmosphere or degrading—which is important for the protection of beneficial insects, such as bees, as well as for determining how long pesticides are active against pest insects.