Domestic Solid Fuel Burning in London: Air Pollution Impacts at Neighbourhood, Street and City Scales

Domestic wood and solid fuel burning was the second largest source of PM 2.5 emissions in London in 2022 and is one of the main contributors to ambient PM 2.5 that can be addressed by local policy and enforcement. Wood and solid fuel burning particulate (WBPM) concentrations were calculated to assess their impact on ambient PM 2.5 at neighbourhood, street and city scale. Wood and solid fuel burning caused short-term PM 2.5 peaks up to 50 μg m -3 at ground level, approximately 10m from the chimneys of residential properties. Emissions were detected from newer burning appliances, highly rated for efficiency, as well as older appliances, when using authorised and exempt fuels as well as with burning seasoned wood. Hotspots of WBPM and PM 2.5 detected on two north and south London transects agreed well with modelled emissions. Good agreement between measurements and odour mapping demonstrates that smell is a reliable indicator of wood and solid fuel burning pollution. Based on data from two representative urban background measurement sites, wood and solid fuel burning particulate was calculated to contribute 8-9% of annual mean PM 2.5 in London for 2022. Over half of this was attributed to urban sources within London with a slightly smaller contribution from the regional background. This study highlights the importance of reducing urban wood and solid fuel burning emissions to support progress towards meeting 2021 WHO air quality guidelines.