Trace Elements From Ocean-Going Vessels In East Asia: Vanadium And Nickel Emissions And Their Impacts On Air Quality

Vanadium (V) and nickel (Ni) are considered the most abundant trace metals in ship exhaust burning heavy fuel oils. This study is the first attempt to estimate the impact of V and Ni from shipping on air quality in East Asia for the year 2015. In this study, emission inventories of V and Ni from shipping and land-based sources were constructed and implemented into the revised aerosol module to simulate ambient V and Ni concentrations. Our results showed that ship emissions contributed the majority of vanadium and were important to nickel emissions in most coastal regions in East Asia, with the contributions exceeding 60% and approximately 40% in some regions, respectively. The simulated ambient V and Ni concentrations has been validated by the measurements, and the comparison revealed there was an obvious improvement (reducing the mean bias by 32%-63%) in the model performance of the V and Ni predictions after including shipping emissions. Our study filled the gaps of trace element contributions in coastal regions and implied that the impact of metals from shipping traffic on regional air quality is worthy of attention in East Asia. Although the International Maritime Organization (IMO) low-sulfur fuel policy has been implemented since 2020, the impact of shipping traffic on trace metals with respect to regional air quality is still important given heavy fuel oils being in use.Key PointsEmission inventories of vanadium and nickel from shipping and land-based sources were constructedThe revised aerosol module was implemented in the Community Multiscale Air Quality to simulate ambient vanadium and nickel concentrationsThe strongest impact of ship emissions to vanadium and nickel was found in southeastern China, accounting for 88% and 70%, respectively