The Issue and societal import: There is little doubt that micro and nanoplastics (MnP) are in our soils across the globe. Numerous studies including my own have found that atmospheric deposition alone is enough to pollute even our most pristine remote areas. What is unknown is what happens to it once it is there. Is it transported by runoff or pushed deeper into the soil? What is the effect of the chemicals leached from MnP on soil microbiome, air and receiving river ecosystems? Many of these (e.g. flame retardants) are ‘forever chemicals’, never break down but continue to cycle in the food chain. What is the threshold before irreversible damage occurs, and have we pass it? These knowledge gaps have far reaching implications for food and water security and survival of the fragile ecosystems that make our planet habitable. PlastiSol seeks to address these urgent questions in an attempt to push the boundaries of our knowledge on this emerging threat. Through studying a cross section of land use soils MnP and associated leachates and the processes that contain or transport these pollutants, this project will advance MnP pollution science beyond considering soil as a sink, evidencing atmospheric and receiving waterway impacts of soil pollution. Furthermore, examining the internal mechanisms of soil MnP movement and leachate release will define the potential groundwater influence, land management activities and storage capacities of different land use soils’ MnP. With this evidenced process knowledge, the impact of soil MnP on the global MnP cycle will be established, enabling soil to be included as a source, transport pathway and sink of plastic pollution, advancing the accuracy of global MnP quantification and the impact of soil MnP on ecosystems and all environmental compartments. Only in understanding the extent and impact of soil plastic pollution can it be effectively managed through change in land use practices and policy advancements.
Overall objectives:
Objective 1: Quantification and characterisation of soil MnP and create a baseline of soil MnPs across different soil systems and use types
Objective 2: Identify the drivers in soil MnP transport, accumulation and contaminant leaching in soils
Objective 3: Develop model-based capacity for assessing MnP risk in soils
