Influence of ship emission control area policy on air quality at Shanghai Port—local and regional perspectives

Abstract

Studies on the impact of ship emission control area (ECA) policies focus mainly on regional or national perspectives, while the impact on local air quality and its associated effects are largely neglected. Here, we quantitatively analyzed the impact of the implementation of the ECA policy on SO2 concentrations at local and regional levels from 2018 to 2021 using a regression discontinuity (RD) model to reveal its positive effects from multiple perspectives. In this model, the time point of policy implementation and concentration of SO2 were considered the breakpoint and observation indicator, respectively, to evaluate the effect of policy implementation. We investigated the impact of the implementation of the 2016 ECA policy in terms of switching to low-sulfur fuel oil on air quality at the Waigaoqiao Wharf in Shanghai Port (local perspective), the change in wharf air quality during 2018–2021, the change in Shanghai City air quality (regional perspective) 2016–2021 and the results show that the mean SO2 concentration decreased from 4.61 to 3.33, 2.68 to 0.03, and 11.32 to 6.73 μg/m3, respectively. The improvement in air quality at the local and regional scales from 2018 to 2021 with respect to the decrease in the mean SO2 concentration were 3.10 to 0.03 and 8.30 to 5.90 μg/m3, respectively. Our results showed that the ECA policy effectively improved air quality at both local and regional scales. As expected, the policy had a greater impact on local air quality, given the impacts of various other emission sources at the regional scale.

Keywords

• Air pollution
• Ship emissions
• Emission control area
• Shanghai Port