Reactive losses of atmospheric VOCs play important roles in the formation of ozone and secondary organic aerosol (SOA) However, identification of the sources of those VOCs most responsible for the formation of these secondary pollutants is difficult., but essential to produce effective control strategies. VOC apportionment based on measured concentrations has been done for many years and PMF is now the most commonly used tool. Recent work has shown that the "initial concentration", that which would have been present in the abssence of reactions can be calculated and apportioned. The difference is the consumed VOCs than can then apportion SOA.

Particulate matter (PM) exposure is linked to premature mortality and morbidity, making source identification crucial for PM emissions control. Organic aerosols (OA) form a major PM fraction, with secondary OA (SOA) potentially more harmful. Barcelona and Athens, impacted by high population density, intense sunlight, and low rainfall, face severe air pollution. While previous studies identified SOA seasonality, sources remain unclear. To investigate this, we analyzed 180 PM2.5 and 180 PM10 filters (2022–2023) using advanced mass spectrometry (EESI-LToF, AMS-LToF) and positive matrix factorization analysis. Our study identifies OA sources driving fine and coarse particulate variations in these Mediterranean cities.

Munich, a major German city, faces air quality challenges with only limited aerosol studies available. Previous research identified traffic, biomass burning, and cooking as key aerosol sources, yet gaps remain in understanding volatile organic compound (VOC) and organic aerosol (OA) origins and seasonal variations. This study aims to elucidate these sources, enhancing air quality management and public health in Munich. In this study, we examine the seasonal variability of OA and VOC chemical composition at a molecular level, aiming to elucidate the contribution of different sources to major VOC, semi volatile organic aerosol (SVOA) and total OA.

South America is the largest contributor to global biogenic emissions, with vast pristine areas undergoing rapid urbanization, deforestation, and biomass burning. This study used online chemical ionization mass spectrometry at a Bolivian Andes station and Positive Matrix Factorization to analyze organic aerosols from diverse biomes. Five PMF factors were identified, revealing that Amazon air masses are dominated by isoprene SOA, while tropical and mountain grasslands contain longer-chain BVOC-SOA. Organic nitrates increase with population density. Urban emissions and volcanic SO₂ influence aerosol composition, highlighting the strong impact of human activities and volcanic processes on atmospheric chemistry.

PM2.5 samples were collected simultaneously during winter and summer 2021 at three Central European sites—Melpitz (Germany), Kosetice, and Frydlant (Czech Republic)—to assess regional aerosol sources and transport pathways. Winter data showed higher contributions from biomass burning and coal combustion, with Frydlant exhibiting the highest coal combustion signals. Summer samples predominantly contained biogenic tracers, such as arabitol and sucrose, indicating stronger biological sources. Backward trajectory analysis confirmed significant aerosol transport from Eastern Europe. The findings highlight the seasonal shift in dominant aerosol sources and underscore the importance of long-range transport in shaping regional air quality.

This study assessed PM_2.5 and its components at two sites in Lucknow using a mobile laboratory. PM_2.5 levels were significantly higher at the industrial site (198.40 µg/m³) compared to the background site (39.63 µg/m³), with organic aerosols (OA) comprising over 50% at both sites. Positive matrix factorization identified primary and secondary OA sources. A unique industrial-related OA (IOA) factor resolved exclusively at industrial site, contributing 18%, and showed a strong correlation with polycyclic aromatic hydrocarbons and heavy metals. Concentrated weighted trajectory analysis revealed that while secondary aerosols were long-range transported, the IOA was predominantly local, emphasizing industrial emissions impact.