DAPPLE D ispersion of A ir P ollutants and P enetration into the L ocal E nvironment A Consortium Research Project funded by the UK EPSRC Engineering for Health, Infrastructure and the Environment Programme, building on the research agendas defined by the APRIL Network and the EUROTRAC ‑ 2 SATURN project. Project overview May 2002 What controls the amount of pollution to which people are exposed on urban roads, and in the buildings alongside? To what extent is it the interaction between the buildings and the flow of air or the position of the greatest emissions relative to locations where people queue? How large is the area of influence of zones where traffic accelerates, compared with that where traffic is queuing, taking into account the variability in emission rates - in particular, that the majority of the pollution comes from a minority of the vehicles? What are the best ways of making localised pollution hotspots less unpleasant and unhealthy? Can we get cleaner air at the same time as improving traffic flow and reducing noise, or do these objectives conflict with each other? What kind of tools do we need to assess localised pollution hot spots, and what simplifying assumptions can these make? For example: in treating the transport of pollution to back-streets, should equal importance be attached to transport over and around buildings? Where does the one route dominate the other? Can the same tools be used for transport-related air quality management as for the assessment of the impact of accidental or terrorist release of toxic or flammable gases? Can these also treat stationary roadside sources such as dry cleaning outlets and small industrial units? Why? We do not yet have the understanding needed to answer fundamental questions about pollution behaviour over short distances in the urban environment. DAPPLE is a large research project that will bring together leading UK expertise in transport and air dispersion studies, aiming to answer the following questions: University of Surrey Prof Alan Robins: wind tunnel measurements and modelling. University of Leeds Prof Margaret Bell, Dr Alison Tomlin: traffic micro-simulation and field measurements. Imperial College Dr Roy Colvile, Dr Mark Nieuwenhuijsen, Prof Helen ApSimon: human exposure measurement and assessment, operational and advanced dispersion modelling, field campaign management. Link via Imperial College to EUROTRAC SATURN project Universities of Bristol and Cambridge Dr Dudley Shallcross, Prof Peter Simmonds, Dr Graham Nickless, Prof Rex Britter: tracer dispersion field measurements, experiment design. University of Reading Dr Stephen Belcher: advanced modelling and urban meteorology, supported by field measurements. University of Cambridge Prof Rex Britter: advanced and operational modelling and interface with user community. APRIL Network ( application of results to operational modelling and interface with user community, including Transport for London, local authorities, Greater London Authority. Who? The spatial variation of pollution from vehicle exhaust at a cross-roads, as calculated by current operational atmospheric dispersion modelling software The spatial variation of pollution from a point source upwind at an urban cross-roads measured in a wind tunnel. The geometry of the junction is not symmetrical – the building in the lower left corner of the figure is taller than its neighbours Examples of pollutant behaviour at a street junction When & Where? April 2002: project start Spring 2003: trial field measurement campaign Autumn 2003 or Spring 2004 (to be confirmed): main field measurement campaign 2004/5: interim results; workshop, conference, presentations April 2006: project end, final report and presentations Field measurements will be made, centred on the junction of Marylebone Road and Gloucester Place in Central London, extending east as far as Madame Tussaud’s and a few hundred metres to the north and south. The understanding gained at this location will then be applied to other locations, with an assessment of the extent to which it is widely applicable throughout London, other UK cities and overseas. Site of DAPPLE field experiments How to get involved DAPPLE will have a project advisory group (PAG). The aim of this group is to ensure that project participants are aware of the needs of users of the research output, and the relationship between DAPPLE and similar work in progress elsewhere. As the composition of this group will be determined during Spring-Summer 2002, interested parties should be in touch with Project Leader Alan Robins tel , fax ), to determine how their interests can be represent on the PAG. DAPPLE is funded by the Engineering and Physical Sciences Research Council, but there will be plenty of opportunities for sponsorship of related work, including Ph.D. projects, smaller research projects, or consultancy. Please contact the relevant Principle Investigator, or the APRIL Network co-ordinator Linda Davies tel , fax ). The DAPPLE field campaigns will include opportunity for other research groups, separately funded, to co-locate measurements, to drive instrumented vehicles through the site, or to use our measurement data for modelling studies. To express an interest in this, please contact Roy Colvile tel , fax ). We also welcome the interest and involvement of operators of bus services through the study site, and owners or occupants of buildings in its vicinity. The DAPPLE wind tunnel and field data will provide excellent opportunities for comparison with related work elsewhere, especially modelling work. To discuss these, contact Alan Robins, as above. We plan to link DAPPLE to a study of London-wide atmospheric chemistry and urban meteorology, to provide a complete picture of determinants of air quality at a range of scales. This will be achieved through the proposed MAPLE study (Meteorology and Air Pollution in London’s Environment) together with a number of APRIL Network proposals and projects on human health and air pollution impacts on vegetation that are in preparation or have recently started. What else? A number of smaller research projects are in progress or will start at participating institutions. The funding of DAPPLE will naturally tend to stimulate these to cluster around the larger project. They will include activities specifically designed to help generalise DAPPLE’s results to other locations. Imperial College’s development of the Urban Scale Integrated Assessment Model (USIAM) is to be linked to DAPPLE. Cyclist carrying sampler to measure exposure to fine particles Contacts Alan Robins, University of SurreyRoy Colvile, Imperial College