To assess the impact of pollution on personal health in outdoor/indoor urban environments, we will develop a physics-based multi-scale approach across biological length scales from the cell, lung, person (surrounded by green infrastructure) up to the neighbourhood scale. We will examine the biophysical components of pollutants that determine their cellular fate, their potential for cell and tissue damage and how this relates to health outcomes. We will use airway models to assess particle deposition and effects on people's health as well as trace the pollution particles through an individual person down to the cellular level. The focus of the analysis will be on the immediate micro-environment (~20m) around a person. The integrated modelling will also represent various intervention scenarios (e.g. roadside hedges or medication for at-risk people such as asthmatics) to assess reduced exposure and corresponding changes in health outcomes. These biologic parameters of exposure will be integrated with the cardio-respiratory response to pollution in 80 participants using a combination of cardio-respiratory, physical activity and personal fine particles exposure monitors. We will numerically model the pollution and air flows at the neighbourhood scale and apply an approach centred on the impact of pollution on health to all aspects of modelling, sensor placement and management of the environment. Thus, any mitigation strategies can be designed to minimize the impact of pollution on health. We will model the dispersion of particles and their micro-physics within the neighbourhood with an emphasis on green infrastructure and their ability to mitigate pollution e.g. hedges can reduce heavy metal pollution. We will examine the physical effects and functional chemistry of the metals and organic components of particles at the ultracellular level to determine their interference to cell metabolism and health. We will use modelling to predict the outcomes of cell fate, so that we can back propagate biological potential of pollution particles (say) through to the individual and into the neighbourhood scale. Thus, modelling will be key at each length scale.

Increasing emission levels of air pollution and greenhouse gases (GHGs) in large urban areas have become a great global concern due to their detrimental impact on human health, climate and the entire ecosystem. In order to cut emission levels, mitigation strategies are in place, however, to evaluate the effectiveness of these mitigation measures, the first step will be to improve the air quality (AQ) monitoring networks by deploying high density and high precision sensor networks to accurately capture spatial variability and emission hotspots in real-time. The traditional and more accurate air quality monitoring instrumentation are large, complex and costly, and hence are only sparsely deployed which provide accurate data but only in few locations, not providing enough information to protect the health of the population or to accurately evaluate the mitigation strategies. The emergence of low-cost sensors (LCS) within the last decade enabled observations at high spatial resolution in real-time, however, due to their poor selectivity, their measurement data is highly dependent on atmospheric composition, and also on meteorological conditions that the data generated by these platforms are of poor quality. In this fellowship, I will develop the first low-cost and high precision air pollution monitor based on photonic integrated circuits (PICs) for the next generation air quality monitoring networks. Photonic integration allows hundreds of photonic components to be fabricated on a single chip, and this step-change in technology will deliver a low-cost, on-chip, versatile instrumentation, stabilised to metrological precision that can be deployed in high density networks to accurately monitor a wide range of pollutants within industrial cities with high spatial and temporal resolution. The captured data can be transferred to the cloud servers over the existing mobile networks from which the users can easily monitor air quality with high accuracy at any time and from anywhere. The proposed instrumentation can also be deployed in balloon and satellite missions for in-situ probing of the constituents of the upper atmosphere, aiding the study of complex atmospheric processes to understand its influence on climate change. EPSRC Open Fellowship will enable me to consolidate my expertise gained over the years in industry and academia and gain my research independence. During these five years, I will have established myself to lead a team of 3 -5 researchers and will have enhanced my research output in novel photonic integrated solutions to combat the challenges faced today. This will aid me to be more competitive in applying for traditional Grants to extend my research portfolio and my research team, and become a leader in this field of research. In 10 years, my vision will be to exploit photonic integration technology for wider applications, including medical imaging, material science and non-destructive testing, and provide outstanding training opportunities to research students and early career researchers who will grow to be future academic and industrial leaders in science and engineering in the UK.

Models of complex chemical processes such as combustion or atmospheric chemistry assume that the molecules taking part are thermalized, that is that their energy is characterized by the temperature of the system. Chemical activation (CA) occurs when the energy released by a reaction is channelled into the products and they have an energy greater than would be thermally predicted. How does the reactivity of these activated species compare with their thermalized equivalents? What is the significance of CA? How can CA be incorporated into chemical models of complex systems? These are the questions at the heart of our project: Complex Chemistry and Chemical Activation (C3A). Aspects of CA have been known about for more than 100 years, indeed 2022 marks the centenary of the Lindemann Mechanism, the first theory proposed to explain the pressure dependence of some chemical reactions. Models of CA have grown in sophistication, yet uncertainties in key processes (energy transfer, calculation of densities of states) limit the accuracy of kinetic and thermodynamic predictions from such systems. Addressing the uncertainties in these aspects of current models through new experimental data and developments in fundamental models is one strand of C3A. More recently, work in this group and elsewhere has shown that systems which were thought to be adequately modelled by thermalized reagents, such as abstraction reactions (e.g. OH + HCHO), do need to considered in the context of chemical activation. In a 2018 review, Klippenstein states: 'These studies ultimately led us to the realization that at combustion temperatures, the foundational assumption of thermalization prior to reaction is not always valid, and further that its breakdown significantly affects key combustion properties' (Proceedings of the Combustion Institute, 36, p77). These phenomena are not limited to combustion; plasma chemistry and the atmospheric chemistry of Earth and other planets provide other important examples of applications. C3A is a collaboration between leading groups from Leeds and Oxford, both with interests in experiments and theory. C3A will generate a wealth of new experimental data, which in combination with theoretical interpretation, will allow us to assess the significance of CA in real systems and provide the tools to allow CA to be accurately incorporated into chemical models of of these processes. The impact of C3A to industry will be facilitated by collaborations with Shell, Dassault Systemes and AirLabs. Such models are essential tools for understanding important questions from current highly practical issues (how can combustion systems be optimized to minimize CO2 emissions and improve air quality) to future questions (biofuels for aviation, novel methods of renewable energy storage such as ammonia generation and combustion) to important, fundamental questions such as modelling the atmospheres of hot-Jupiter exo-planets or the interstellar medium. The accurate assessment and incorporation of CA into such models will significantly enhance their reliability and predictive value.