Integration of remote and in situ optical techniques to estimate fine dust and gaseous emissions in an industrial complex in South Korea

Rapid industrialization has intensified air pollution, particularly in areas where industrial and residential zones overlap. This study analyzed emissions from the Yeosu Industrial Complex, South Korea, a major source of volatile organic compounds (VOCs), methane (CH₄), sulfur dioxide (SO₂), nitrogen dioxide (NO₂), and particulate matter (PM). Advanced remote and in situ optical techniques—solar occultation flux (SOF), sky differential optical absorption spectroscopy (SkyDOAS), mobile extraction Fourier transform infrared spectrometry (MeFTIR), sniffer 4D, and LiDAR—were employed to assess spatial pollutant distribution across five zones. Zones A and B exhibited the highest emissions (8,622,468 kg/year and 21,826,416 kg/year), largely due to petrochemical and rubber manufacturing activities. Pollutants, particularly alkanes, NO₂, and SO₂, were highest during southeasterly winds, which transported emissions to nearby residential areas, increasing health risks. A comparison with the Clean Air Policy Support System (CAPSS) inventory highlighted underestimations of VOC emissions in national records. Discrepancies in PM₁₀ measurements by Sniffer 4D (2–6 µg/m³) and LiDAR (14–15 µg/m³) in zone A emphasized the importance of integrating measurement methods to improve emission accuracy. This study demonstrates the potential of combining mobile and remote sensing techniques to enhance emission inventories and provides critical insights for targeted air quality management in industrial-residential interfaces.