Regional Fireworks Pollution over East and Southeast Asia from Airborne Observations around the Spring Festival Period

Abstract

Fireworks are spectacular, but they also pollute the atmosphere. While fireworks are known to rapidly increase local pollution levels, the regional influences and nanosized appearance of fireworks-related particles are poorly understood. This study collected aerosol particles over East and Southeast Asia during an airborne campaign and observed the shapes and compositions of individual particles using transmission electron microscopy. We found significant amounts of fireworks-related particles (FWPs), which were characterized by the presence of Ba, Sr, or Bi, during four flights over or near the Philippines, Taiwan, and Korea in February 2024, around the Spring Festival period. These characteristic elements were found to be nano- to submicron-sized grains embedded mainly within Mg-sulfates and coexisted with F, Al, K, Cr, and other trace components. Our airborne measurements showed that the FWPs were detected at altitudes ranging from several hundred m to 3000 m, covering areas of several hundred km for each flight. The highest number fraction (75%) and estimated mass concentration (10 ± 1 μg m–3) of FWPs were observed over the Yellow Sea. These results suggest that these particles travel across large areas, contributing to regional pollution and potentially having adverse effects on human health due to their small size and specific composition.