A systematic review of the pollution and health impacts of low emission zones

Abstract

Air pollution is one of the most significant issues that urban areas face, with 7 million mortalities worldwide each year as a result (UN, 2023). Different policies have been introduced to mitigate the emissions of harmful pollutants through a variety of means, including Low Emission Zones (LEZs), which have been introduced in cities to reduce the number of journeys made by highly polluting vehicles. This study uses two robust regression models to answer two research questions related to the key metrics of pollutant concentrations and long-term health benefits following LEZ implementations. The two pollutants, Nitrogen Dioxide (NO₂) and Fine Particulate Matter (PM_2.5), were examined with the “openair” software in R, which is used to analyse trends in air pollution. The impact that different policies have on several health metrics were also examined through data collated from literature reviews. The results obtained after analysing London’s LEZ (2008) and ULEZ (2019) were then used to evaluate the viability of Manchester’s Clean Air Plan. The results show that there is statistically significant evidence of LEZs curbing pollution levels, which in turn contributes to long-term health benefits. It is concluded that the current trajectory of Manchester’s air pollution policy, which falls short of having an LEZ, is likely not impactful enough on pollutant concentrations and health, especially in relation to PM_2.5 levels. Future research at planned time intervals is suggested for modelling the extent of the impact of Manchester’s Clean Air Plan. However, results demonstrate the importance of curving harmful pollutants, which should be taken into consideration by policy makers in other cities as well.