Source apportionment of key air pollutants in Naples using a high-resolution WRF-CAMx-PSAT modeling framework

This study quantifies the contributions of major emission sources of road transport, maritime activities, and residential heating to air pollution in Naples using a high-resolution WRF-CAMx-PSAT modeling framework. Refined emission inventories and model validation against Environmental Air Quality Agency of Campania Region (ARPAC) monitoring data ensured robust simulation of nitrogen dioxide (NO2), fine particulate matter (PM2.5), coarse particulate matter (PM10), and sulfur dioxide (SO2) concentrations. The model was applied over a domain covering the Campania region, in Southern Italy, simulating key atmospheric pollutants, including NO2, PM2.5, PM10 and SO2. The source apportionment analysis revealed distinct spatial patterns in pollutant contributions across the five receptor sites. Road transport and residential heating consistently emerged as dominant sources of NO2, PM10 and PM2.5, particularly within urban and suburban contexts. Maritime emissions were found to significantly impact SO2 and NO2 concentrations at coastal sites, especially near the Port of Naples. Natural sources with sea salt, and secondary organic aerosols also played a non-negligible role in PM10 and PM2.5 levels, especially at inland locations. These findings provide actionable insights for targeted emission reduction strategies and evidence-based air quality management in complex coastal urban settings.