Towards a Better Understanding of Pesticides in the Atmosphere
Theme: Environmental Aerosols
Start date: Cohort 2: 2020
Supervisors: Prof Hugh Coe, Dr David Topping
Previous research has identified that pesticides can be transported long distances in the atmosphere as aerosols particles. My PhD project aims to develop a further understanding of how transportation of pesticides occurs. This will be done through the development in understanding key properties(volatility, vapour pressure, solubility, toxicity, photodegradation and chemical reactivity)and how these properties effect the pesticides transport pathways and will be considered on both short-range(local)and long-range(regional and continental) timescales. It has been identified that pesticides enter the atmosphere through evaporation by a process termed ‘spray drift ‘causing them to be lost from the application site. Once entering the atmosphere, the low volatility of many pesticides makes it ideal for them to be absorbed onto the surface of atmospheric particles and reside in the particulate phase. Pesticides have been observed at large distances from the source and in remote regions, such as the Arctic, with current research unsure of the mechanisms involved to reach these remote locations. The properties will greatly impact the pesticides ‘ability to undergo this process and thus the fate of the pesticide. This is important due to the environmental and health impacts found in the exposure to pesticides such as bioaccumulation in the environment.
The project aims to bridge the gap in understanding by identifying the atmospheric mechanisms which results in pesticides being transported from the application site to the site of deposition. This will be done through analysis of single particles, bulk and field studies before allowing findings to be integrated into models to further understand the behaviour of aerosols in the atmosphere.