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[MZZ42-P07] Effect of the 2020 Global Surfur Cap on sulfur and trace element concentrations in atmospheric aerosols in Nagoya
Keywords:atmospheric aerosol, sulfur concentrations, Global Sulfur Cap 2020
One of the main components of atmospheric aerosols is sulfur (S), which primarily originates from the combustion of fossil fuels. Due to concerns about its impact on the environment and health, it is important to reduce its emissions. In January 2020, the International Maritime Organization (IMO) introduced a regulation to limit the sulfur content of marine fuel oils used in most sea areas to 0.5% or less (Global Sulfur Cap 2020). This regulation restricts the use of high-sulfur C-heavy fuel oil and recommends the use of low-sulfur fuels. Combustion of high-sulfur heavy oil is known to emit large amounts of vanadium (V) and nickel (Ni). Therefore, this study aims to measure the concentrations of S and trace elements including V and Ni in atmospheric aerosols in Nagoya City before and after the implementation of the heavy oil regulation from 2018 to 2020, and to verify the effects of the regulation by examining fluctuations in these concentrations and the correlations between the elements.
Atmospheric aerosol samples were collected weekly on quartz filters using a high-volume air sampler from the rooftop of the Nagoya City Institute for Environmental Sciences (NCIES) in Minami Ward, Nagoya City. NCIES is located approximately 2 km from the shoreline of the port of Nagoya. After pulverizing the filters, the S concentration was measured with an elemental analyzer (Vario MICRO cube, Elementar), and the concentrations of trace metals were analyzed using ICP-MS (Agilent 7700x) after HF/HClO4 digestion.
The concentrations of S, V, and Ni in atmospheric aerosols showed an increasing trend in the spring of 2018 and the summer of 2019, but this trend was not observed in 2020, and the concentrations decreased throughout the year. It has been reported that in the summer, a southward wind blows due to sea breezes, carrying ship exhaust particles from the coastal areas in Nagoya City (e.g., Osada et al., 2019). In the summers of 2018–2020, the south wind was also predominant. The number of ship arrivals at Nagoya Port from 2018 to 2020 was 33,404 ships, 32,576 ships, and 29,243 ships, respectively. While the number of arrivals decreased in 2020 and the reduction between 2019 and 2020 was 10%, the decrease in V concentration during the same period was 65%. This suggests that the decrease in V concentration was significantly influenced by the use of low-sulfur fuel due to the sulfur regulation. Additionally, the correlation between S and V concentrations in the summer differed between 2018–2019 and 2020. This corresponds to the difference between the C-heavy oil combustion in 2018–2019 and the impact of low-sulfur fuel combustion in 2020, indicating the impact of the sulfur regulation,.
Atmospheric aerosol samples were collected weekly on quartz filters using a high-volume air sampler from the rooftop of the Nagoya City Institute for Environmental Sciences (NCIES) in Minami Ward, Nagoya City. NCIES is located approximately 2 km from the shoreline of the port of Nagoya. After pulverizing the filters, the S concentration was measured with an elemental analyzer (Vario MICRO cube, Elementar), and the concentrations of trace metals were analyzed using ICP-MS (Agilent 7700x) after HF/HClO4 digestion.
The concentrations of S, V, and Ni in atmospheric aerosols showed an increasing trend in the spring of 2018 and the summer of 2019, but this trend was not observed in 2020, and the concentrations decreased throughout the year. It has been reported that in the summer, a southward wind blows due to sea breezes, carrying ship exhaust particles from the coastal areas in Nagoya City (e.g., Osada et al., 2019). In the summers of 2018–2020, the south wind was also predominant. The number of ship arrivals at Nagoya Port from 2018 to 2020 was 33,404 ships, 32,576 ships, and 29,243 ships, respectively. While the number of arrivals decreased in 2020 and the reduction between 2019 and 2020 was 10%, the decrease in V concentration during the same period was 65%. This suggests that the decrease in V concentration was significantly influenced by the use of low-sulfur fuel due to the sulfur regulation. Additionally, the correlation between S and V concentrations in the summer differed between 2018–2019 and 2020. This corresponds to the difference between the C-heavy oil combustion in 2018–2019 and the impact of low-sulfur fuel combustion in 2020, indicating the impact of the sulfur regulation,.