Implications of electric mobility on health and environmental justice

Traffic-related air and noise pollution continues to pose significant health threats to the urban population. This study develops a transferable methodology to estimate key health co-benefits of electric mobility at a city scale. It is the first study to consider electrifying both passenger and goods vehicles. Using city-wide data, we adopt a bottom-up approach based on empirical traffic volume, vehicle mix and speed on the road network. Under four scenarios of different vehicle types, noise propagation and air dispersion models are used to estimate reductions of noise level and five roadside air pollutants associated with electric mobility. Combining with population distribution data, health outcomes are calculated in terms of the number of preventable deaths and year of life lost in disability. Hong Kong is used as a case study because of its high population density, importance of buses, and role as an international transport and logistics hub. The findings reveal that the total preventable deaths per year combining all scenarios is 836.2, which includes 512.2 deaths attributable to reduced traffic noise and 324.1 deaths attributable to lower traffic-related air pollution. Each year, the total year of life lost due to disability (YLD) reduction amounted to 21,264.8. Comparing across vehicle types, electrifying heavy-duty vehicles, notably buses and medium- and heavy-duty trucks, generates the greatest public health benefits. Notably, low-income, ageing and high-unemployment neighbourhoods can benefit from reductions in preventable deaths by 12.23-12.96 per 100,000 population, compared to 10.84-10.93 per 100,000 population in their counterparts. This indicates the potential of electric mobility in overcoming the environmental injustice caused by internal combustion engine vehicles in a compact city.