Evaluating Public Exposure to Airborne Particulates from Major Incident Fires: A Back Trajectory Plume Modelling Approach

Major incident fires at industrial facilities, particularly waste sites, pose a significant risk to public health because of the large amounts of hazardous airborne pollutants released into the ambient environment. Monitoring carried out during these fires is limited in spatial resolution, meaning that the full extent of population exposure is difficult to estimate. In this study, we overcome these limitations by using a novel back-trajectory plume modelling approach, applied to PM10 emission data from a significant tyre fire that occurred in the UK in 2010. This approach allows the calculation of an hourly emission rate that is then used in the forward modelling mode to predict hourly plume concentrations. An analysis of the modelled plume indicated that, as a reasonable worst case, up to 8,000 residents in areas adjacent to the fire may have been exposed to PM10 concentrations that are deemed hazardous. Moreover, a vulnerability analysis showed that the exposed population had disproportionately poorer health than the national average, thus raising concerns about environmental justice. This work highlights the need to improve regulatory controls for waste sites located near urban areas and for further research on population exposure and the health impacts of major incident fires.