Developing a new chemical link between composition, abundance and sources of black carbon in a major urban environment

The air around us is vital for survival, yet every breath transfers small particles of pollutants into our lungs. It is estimated that in the UK alone long-term exposure to airborne particulate matter (PM) results in 340,000 life-years lost, equivalent to c.29,000 deaths a year [1]. Black carbon (BC), emitted from diesel and other fossil-fuel and biomass combustion, is a significant contributor to PM, with specific adverse effects on health [2]. BC is also an important contributor to global warming by trapping planetary radiation. A recent UN report concluded that control of BC would have immediate and multiple benefits for human well-being [3]. Despite substantial UK reductions in emissions and concentrations of black smoke/BC since the 1960s, poor urban air quality remains a government priority area (Parliamentary Environment Committee, 2016). Glasgow, the project focus area has, and historically had, amongst the highest air pollution levels outside London. Despite its importance, BC remains poorly understood. Its atmospheric measurement by optical absorption, and its quantification in soils, the fate of the majority of emitted BC, are both operationally defined and in the latter can yield orders of magnitude difference in abundance [4]. Furthermore, there is little information on the precise chemistry of BC other than it contains carcinogenic polyaromatic compounds [5]. The overall aim of this project is to enhance understanding of BC environmental processes by providing a chemical link between composition, abundance and sources of BC, both in the current context, but also through examination of the historical record of BC contained in soil/peat profiles. The key novelty is the application of a new chemical methodology, hydropyrolysis (HyPy), which isolates, quantifies, and characterises BC on a secure chemical basis, capturing the full BC spectrum. The project has been designed in collaboration with the CASE partner, Air Monitors Ltd, who are a major developer and supplier of particulate matter and BC sampling and measurement instrumentation. Project outcomes relevant to Air Monitors Ltd business include data that informs calibration and improvement of BC monitoring equipment and that highlights the importance of characterizing BC to end users, e.g. governmental and industry. Air Monitors Ltd. have committed to provide both equipment and training to the PhD student in obtaining PM samples, in current commercial BC monitoring application and in data interpretation.

Objectives:
1) Determine the contemporary concentrations, chemical composition and sources of BC pollution in Glasgow City
2) Compare the snapshot of current BC composition and abundance with historical records from soil vertical profiles of BC
abundance and composition from the last few decades