Linking Air Quality and Marine Ecosystem Responses to Biomass Burning Aerosols in the Adriatic Coastal Zone

Climate change projections point to a sustained rise in emissions from biomass burning (BB), highlighting the need for a comprehensive evaluation of the environmental impacts of BB-derived aerosols (BBA). Of particular importance is the organic aerosol fraction (BBOA), which is chemically reactive and undergoes complex transformations during atmospheric ageing. These processes are especially critical in coastal regions, where strong coupling between atmospheric and marine systems can amplify environmental and ecological risks. In this study, we apply a multidisciplinary framework combining atmospheric chemistry, aerosol characterization, modeling, marine science, and toxicology to investigate the physicochemical properties of BBA, with emphasis on BBOA, and to assess how their atmospheric evolution affects air quality and marine ecosystems.A comprehensive field campaign was conducted in the central Adriatic region, an area frequently impacted by intense wildfire events yet still poorly characterized in terms of BB influences. During controlled pinewood biomass burning experiments in April 2025, real-time measurements were conducted using state-of-the-art instrumentation, including a Scanning Mobility Particle Sizer (SMPS), an Optical Particle Counter (OPC), gas analyzers, and a CASS system combining an Aethalometer and a Total Carbon Analyzer. In parallel, fine particulate matter (PM2.5), volatile organic compounds (VOCs), and size-resolved aerosols (0.010–32 µm) were collected for comprehensive offline analyses, including the determination of trace metals, major ions, anhydrosugars, polyols, organic carbon, and aerosol oxidative potential.To link atmospheric processes with marine impacts, laboratory exposure experiments were performed to evaluate the effects of ambient BB aerosols and model black carbon materials on the growth of representative marine phytoplankton species (such as Emiliania huxleyi, Cylindrotheca closterium, Melosira nummuloides, Synechococcus sp.) under controlled conditions (18 °C; 16 h light/8 h dark). These experiments reveal species-specific physiological responses to BB aerosol exposure. Overall, the integrated dataset provides new insights into the properties and evolution of BB aerosols and their cascading impacts on coastal air quality and marine ecosystem health in the Adriatic region, with broader implications for other vulnerable coastal environments.This work was supported by Croatian Science Foundation project IP-2024-05-6224 ADRIAirBURN.