Integrated Research Observation System for Clean Air (OSCA)

"Poor air quality is the largest environmental risk to Public Health in the UK" (DEFRA, 2017) and is consequently a focus of a range of regional and national policy interventions. However, since our transport systems, the way we heat our homes, our energy supply, our use of solvents and our agricultural systems are all changing, we know that profound changes in emissions and trends in air pollutants are likely in the coming years and indeed are already taking place. We need to understand our changing atmospheric composition, to ensure air quality policy has maximum benefit for the protection of human and environmental health.

The Clean Air: Analysis and Solutions Programme identifies the need for new capability to predict future changes in the sources, emissions and atmospheric processes responsible for air pollution. The OSCA project addresses this need through a multidisciplinary research activity, combining state-of-the-science atmospheric observations, laboratory studies, new data processing tools and integrated scientific synthesis to deliver new understanding of urban air pollution. OSCA will:

-Deliver improved quantification of emissions, combining lab measurements of brake & tyre wear sources, and measurements of the total fluxes of particulate matter (PM) and nitrogen dioxide (NO2) from the BT Tower in London. Nonexhaust emissions comprise up to 70% of traffic-derived PM10, are poorly quantified, and whose relative importance will increase with UK fleet decarbonisation. Real-world emission measurements underpin air quality predictions and avoid dependence upon manufacturer data.

-Provide a definitive, state-of-the-science assessment of UK urban air quality through exploitation of the new RCUK-funded urban air quality Supersites in London, Birmingham and Manchester to deliver comprehensive, continuous and long-term measurements of atmospheric composition. These data will characterise the changing UK pollution climate, identify subtle emission trends during implementation of regional air quality policies, and provide a key resource for evaluation of ongoing trends.

-Develop new mathematical analyses to identify emergent trends / responses to policies and apply these alongside established methods to address key science uncertainties - e.g.: to assess the trends and changing sources of NO2; to provide definitive quantification of the contributions of non-exhaust traffic, woodsmoke and cooking activities to PM; to identify trends in and contributions to ammonia emissions; to identify changes VOC emissions - precursors to ozone formation.

-Provide data and infrastructure to underpin the wider Clean Air Programme, including development and deployment of novel sensor networks (QUANT); data to validate models and health effect calculations (InSPIRE and DREaM); insight into air quality response to policy initiatives (ANTICIPATE); sensor testing and pollutant source identification (APEx).

-Enable community mobilisation through intensive field campaigns, targeted at understanding the changing gas-phase reactivity climate of the UK atmosphere (which governs production of secondary PM and ozone), and the sources and chemical composition of atmospheric aerosols.

OSCA findings will support policymakers through a range of established relationships the PIs already maintain. These include engagements within the supersite host cities, and links to relevant national bodies, including Defra, DfT, DoH, PHE and the EA. The OSCA deliverables provide important new data and novel scientific approaches central to the assessment of future changes in the sources, emissions and atmospheric processes governing air pollution in the UK - the core of WP1 of the Clean Air programme. OSCA is fully embedded into the wider programme, informing policy decisions, monitoring the impacts of decisions, and feeding public health research and outcomes.

OSCA is an underpinning proposal to the UKRI Clean Air Programme and will deliver significant impact through support for multiple projects, whilst also generating wider impacts in its own right. The main direct beneficiaries of the research are the agencies invested in the activities of the programme, national and regional policy makers and public health professionals. Since the Met Office and STFC are delivering the Framework for Clean Air Analysis in WP4 they are clear beneficiaries of the outputs. The key stakeholders at national level are the Department for Environment Food and Rural Affairs; the
Department for Transport; and Public Health England. At regional level key stakeholders are the combined authorities in London; Manchester and Birmingham and Transport for Greater Manchester and Transport for London. PHE Consultants in the regions provide public health advice to regional government.

OSCA project outcomes result from PIs working closely with policy makers at regional and national level to identify key areas of concern. Emissions of NOx are of immediate and direct importance to UK air quality policy and evaluating ongoing changes in emissions has direct policy relevance given the traffic fleet is changing rapidly. Whilst particulate traffic

exhaust emissions are relatively well understood, the quantification of non-exhaust emissions that OSCA will deliver has direct benefit to national and regional policy making as the UK fleet electrifies and conventional exhaust emissions diminish. OSCA will provide policy makers with new information on the contributions to the urban mass burden from sources such as wood burning and cooking which can be used to base future decisions regarding PM control. OSCA will provide new data on urban ammonia and source attribution between agriculture and urban sources and so support policy makers in their prioritisation and strategies for reducing emissions.

Identifying the drivers of trends in pollutant concentrations and attributing changes to specific interventions and policies is extremely challenging, given the large number of confounders that exist. OSCA will develop approaches to tackle this problem, utilising a wide range of data currently available to assess the extent to which such causality can be attributed and will provide a framework for wider modelling work that will investigate this. Such tools will be widely disseminated for other stakeholders to use themselves.

OSCA measurements of the composition of air pollution, along with source attribution, will provide observational constraints to other projects within the Clean Air programme who are forecasting air quality, modelling policy interventions, assessing air quality sensor networks, measurement innovation, assessing exposure and identifying health impacts. The information and expertise from OSCA will therefore inform public health professionals investigating the health impacts of air quality in UK cities.

This work has the potential to generate significant impact with regional authorities in other areas of the UK, through the dissemination of findings, and the translation of tools. The project will seek out aspects of the research that have wider applicability to other cities and work to support decision-making more broadly in the UK.

Lastly, in many cases air quality improvements will not be delivered by policy alone but require public engagement, including technology uptake and behaviour change to deliver cleaner air. The willingness of the public to embrace change is very dependent on their knowledge of the problem, their trust in the solutions and engagement with the change process. By publicising our findings on local issues derived for example from local source apportionment, we have the potential to generate impact through region-specific public engagement, raising awareness of air pollution sources and the activities that drive emissions.