UK combustion emissions of PM2.5 cause ~13,000 premature deaths in the UK per year, while an additional ~6,000 deaths in the UK are caused by non-UK European Union (EU) combustion emissions, according to a new study by researchers from MIT, published in the ACS journal Environmental Science & Technology.
Steve Yim and Steven Barrett found that the leading domestic contributor is transport, which causes ~7,500 early deaths per year, while power generation and industrial emissions result in ~2,500 and ~830 early deaths per year, respectively. They estimate the uncertainty in premature mortality calculations at −80% to +50%, where results have been corrected by a low modeling bias of 28%.
They also estimated the total monetized life loss in the UK at £6–62 billion per year (US$9.6 to 99.5 billion)—0.4–3.5% of gross domestic product (GDP).
For Greater London, where PM concentrations are the highest and exceed EU standards, they estimated that non-UK EU emissions account for 30% of the 3,200 air quality-related deaths per year.
Yim and Barrett derived a temporally, spatially, and chemically resolved emissions inventory for the UK (at high resolution) and the EU (at low resolution) suitable for use in a state-of-the-science atmospheric chemistry-transport model. They then evaluated meteorological and baseline air quality simulations to quantify the extent to which the modeling approach reproduces observed meteorological fields, total PM, and other species concentrations due to all emissions. To estimate premature mortality impacts, they overlaid sector-attributable PM concentrations onto population density, and multiplied the resultant exposure by a concentration−response function.
Approximately one-sixth of PM2.5 exposure attributable to transport (as a whole) is BC [black carbon]. This can be compared to 1−2% for other sectors and is indicative of the extent to which road transport has localized impacts due to the positive correlation between road transport emissions and population density. On the other hand, sulfate impacts of road transport represent 1% of the sector’s total PM2.5 impact, which can be compared to figures of 10% for industry to 62% for power generation. This is consistent with the low sulfur fuel used in road transport in the UK and the high sulfur coal-fired power stations in use. Taken together, these findings suggest further efforts to reduce UK power station SOx emissions should be assessed for their costs and benefits, while for road transport the planned reductions in allowable primary PM emissions may have significant health benefits.—Yim and Barrett
Their analysis suggests that the public health impacts of road transport are likely to be 50% greater than fatal accidents as measured by attributable premature mortalities. However, they note that an air quality-related mortality is not equivalent to a fatal road accident in terms of life years lost on average. Approximately half of those who died on UK roads in 2007 were under 40, implying a loss of life of ∼35 life years per mortality, compared to the ∼12 life years lost per air quality mortality. In other words, road accidents are still likely to result in a greater loss of life years than road transport emissions.
The extent of transboundary pollution between the UK and other EU member states can be illustrated by noting that (i) one-third of premature mortalities in the UK caused by combustion emissions are due to emissions from other EU member states, and (ii) UK combustion emissions cause one- third again as many early deaths in the rest of the EU as they do in the UK. These results indicate that further policy measures should be coordinated at an EU-level because of the strength of the transboundary component of PM pollution, and that the EU as a whole is responsible for air quality in any given member state.—Yim and Barrett
Steve H. L. Yim and Steven R. H. Barrett (2012) Public Health Impacts of Combustion Emissions in the United Kingdom. Environmental Science & Technology 46 (8), 4291-4296 doi: 10.1021/es2040416