Back trajectory modelled PM10 plumes: population vulnerability profile from an uncontrolled fire

Large industrial fires release significant concentrations of particulate matter, yet the scale of exposure and the socioeconomic profile of those affected remain poorly characterised in the literature. The UK’s Air Quality Cell (AQC) service provides health protection advice during the response phase to major air pollution incidents routinely caused by uncontrolled industrial fires. The AQC’s plume monitoring is a novel global service whose results have been used to characterise the vulnerability of exposed populations. The AQC monitored PM10 concentrations during a large-scale uncontrolled tyre fire in the town of Mexborough (UK). Spatial coordinates and AQC monitoring results enabled 22 hourly back trajectory plumes to be generated using ADMS-STAR back trajectory modelling software were then spatially averaged in ArcGIS Pro. Concentrations were categorised using the US EPA’s Air Quality Index (AQI). Output Areas intersecting the plume were profiled against socioeconomic indicators and compared to English 50th percentile (median) benchmarks. AQI analysis indicated that 24,952 residents were exposed to concentrations classified as ‘Unhealthy for Sensitive Groups’ or worse. Of these, 31.5% (n = 7,856) were exposed to ‘Hazardous’ or ‘Beyond AQI’ concentrations, predominantly in Mexborough town. Vulnerability profiling revealed above-median prevalence of self-reported pre-existing health conditions, non-professional employment, and lower educational attainment in exposed populations. Corroborating this, the Index of Multiple Deprivation scores confirmed disproportionate exposure among more deprived communities. Back trajectory modelling demonstrates that field monitoring likely underestimates peak PM10 concentrations due to logistical and instrument constraints. Exposed populations carry a greater burden of pre-existing health vulnerability and socioeconomic deprivation — raising important questions for environmental justice and land-use policy.

Key messages

• Back trajectory modelling indicates that field monitoring underestimates PM10 exposure during industrial fires.

• Deprived communities bear a disproportionate burden from exposure to an airborne plume caused by an uncontrolled industrial fire, highlighting environmental justice and land-use policy concerns.