An Investigation into the Effects of Off-Shore Shipping Emissions on Coastal Black Carbon Concentrations

Shipping emissions are recognised as a significant but poorly understood contributor to air pollution in the UK. Away from port, lower grade fuels are permitted to be used, to the extent that sulphur emissions from shipping were forecast to exceed those from all land-based sources in the EU by 2020. To examine the impact of black carbon emissions from shipping, an Aethalometer was installed at Goonhilly Downs on the Lizard peninsula in Cornwall UK, which is typically downwind of busy shipping lanes, with very low background pollution levels, for a full year starting in November 2012. Black carbon and UV component concentrations were combined with local wind speed and direction data to differentiate between shipping emissions, local sources and long-range transport. Black carbon concentrations were compared with PM2.5 mass concentrations from Plymouth Centre to allow for the influence of changes in regional background particulate concentrations. Black carbon concentrations showed no substantial increment above other rural UK locations, although some time periods show small elevated concentrations which could be attributed to emissions from the nearby shipping lanes. The long-term (annual) average contribution to black carbon concentrations from off-shore shipping is estimated to be less than 0.1 mu g m(-3), with the hourly peak values being in the range 1-2 mu g m(-3).