Investigating the impacts of increased uptake of electric vehicles on air quality and health

Abstract

Globally, nine million deaths per year are attributed to exposure to air pollution, as estimated by the Lancet Commission on Pollution and Health (Landrigan et al., 2018). In the UK, approximately 40,000 deaths per annum are attributed to exposure to PM2.5 and NO2, costing society nearly £20 billion annually from the health-related consequences of people suffering diseases and early deaths (Royal College of Physicians, 2016). Road transport emissions are a major source of air contaminants, and in 2016 they contributed to 12.4% of PM2.5, 11.7% of PM10 and 33.6% of NOx (DEFRA, 2018); the latter contributing 80% of NO2 concentrations at roadsides (DEFRA and DfT, 2017a). Additionally, vehicular emissions account for 24% of greenhouse gas (GHG) emissions (BEIS, 2018a). To mitigate air quality pollutants and GHGs, the UK government’s Road to Zero strategy plans to limit the sale of new cars and vans to ultra-low emissions vehicles (ULEVs), mainly focusing on electric vehicles (EVs), by 2040 with the aim of forming an entire stock of ULEVs by 2050. Currently, the government is investing £1.5 billion in measures dedicated to increasing the penetration of ULEVs and optimising their manufacturing and infrastructure. These measures would result in changes in the vehicle fleet mix and consequently reductions in emissions and pollutant concentrations. A detailed investigation is needed to quantify their impact. In this research, the impact of changes in the vehicle fleet with the increased adoption of EV, on air quality and health was investigated via scenarios that consider different levels of future EV uptake replacing conventional vehicles in Newcastle and Gateshead. Road transport network data for 2010 for the study area was acquired and updated to provide the 2014 Baseline, considering traffic growth for each vehicle class. The Baseline traffic model was validated following the Design Manual for Roads and Bridges criteria. The resulting emissions rates were calculated using an emissions model. The dispersion of pollutants was modelled taking into consideration the effect of meteorological factors. The air quality model was validated following DEFRA Technical Guidance. The 2014 Baseline traffic was updated to business-as-usual (BAU) for 2030. Six future scenarios were developed based on this BAU. These scenarios include: 1. ‘CCC’: Committee on Climate Change proposal for 30% of cars and 38% of vans being electric; 2. ‘E-Bus’: electrification of all buses; 3. ‘E-Car’: electrification of all cars; 4. ‘E-Car_E-Bus’: electrification of all cars and buses; 5. ‘E-Car_E-LGV’: electrification of all cars and LGVs; and 6. ‘All-EV’: electrification of all vehicles. Emission and dispersion models were applied to determine changes in air quality in response to the BAU and the six scenarios. The results indicate that pollution concentrations in 2030 would be reduced to varying extents compared to the 2014 Baseline. The annual mean reductions at the 66 General Practitioner (GP) sites were averaged for all 2030 scenarios across the study and showed a drop of 8 µg/m3 in NO2 levels and 3 µg/m3 in PM10 and PM2.5 levels. The Department of Health recommended dose-response coefficients, which describe the association between exposure to a certain amount of pollutants and the probabilities of being admitted to hospital and early mortality, were applied to the pollutant reductions at each GP site to estimate the number of respiratory hospital admissions at each GP location. Disease burden estimates suggest that the 2030 BAU will reduce hospital admissions by 1,297, representing 13% of the 9,693 cases recorded in 2014. It was noted that a large reduction in hospital admissions would occur due to decreases in NO2 concentrations. In the All-EV ii scenario, hospital admissions are expected to be reduced by 1,377, which could also nearly be achieved either by electrifying all cars and all buses or electrifying all cars and LGVs with a lower cost in relation to All-EV. Reducing premature mortality is estimated to account for 14 to 16 incidents. This study shows that the EV uptake scenarios will result in significant reductions in air pollution emissions and concentrations and consequent hospital admissions compared to BAU taking into consideration the relatively small population of Newcastle and Gateshead.