Chemical Characterization and Source Apportionment of Atmospheric Aerosols

Atmospheric aerosols comprise a complex mixture of solid and liquid particles suspended in air, originating from both natural phenomena and human activities. Chemical characterisation deciphers their composition—such as organic carbon, inorganic ions and trace metals—using techniques including aerosol mass spectrometry and ion chromatography. Source apportionment employs receptor models and isotopic tracers to quantify contributions from traffic, industrial emissions, biomass burning, soil dust and secondary formation. Together, these approaches illuminate aerosol lifecycles, reveal regional and seasonal patterns, and underpin strategies to mitigate air pollution, reduce health impacts and inform climate models. Advances in in situ instrumentation, data-fusion methods and high-resolution modelling have refined our understanding of primary versus secondary aerosol formation, the oxidative potential driving health effects, and the transport pathways linking urban, rural and transboundary pollution.

Research from Nature Portfolio

Recent studies in South Asia have shown that local incomplete combustion dominates both chemical composition and oxidative potential of fine particles. In a metropolitan region of northern India, ammonium chloride and primary organic aerosols from traffic and residential heating were found to govern the particulate oxidative potential inside the city, whereas outside, secondary ammonium sulfate, nitrate and organic matter from biomass burning prevailed. This work underlines the effectiveness of targeting inefficient combustion for health-oriented mitigation. Another investigation in eastern China combined dual-isotope measurements with chemical transport modelling to apportion black carbon sources in Shanghai. It revealed that while fossil fuel emissions account for the bulk of summer black carbon, residential biomass burning has risen sharply in winter, contributing nearly half of pollution during haze events. These findings emphasise the growing impact of residential combustion on urban air quality and climate forcing, and call for emission controls beyond traffic and industry sectors.

Chemical Characterization and Source Apportionment of Atmospheric Aerosols publication trend

The graph below shows the total number of articles in chemical characterization and source apportionment of atmospheric aerosols across all publications each year (not limited to Nature Index journals).

Technical terms

PM2.5: Particulate matter with aerodynamic diameter less than 2.5 µm.

Organic aerosol (OA): Carbon-containing particles derived from primary emissions or secondary formation.

Oxidative potential (OP): The ability of particulate matter to generate reactive oxygen species.

Source apportionment: Statistical and isotopic methods that assign ambient aerosol mass to individual emission sources.

Positive Matrix Factorization (PMF): A receptor modelling technique that resolves mixed chemical data into discrete source profiles and contributions.

Chemical transport model (CTM): A computer simulation of the emission, chemical transformation, and movement of atmospheric pollutants.

References

1. Local incomplete combustion emissions define the PM2.5 oxidative potential in Northern India. Nature Communications (2024).
2. Multiyear high-temporal-resolution measurements of submicron aerosols at 13 French urban sites: data processing and chemical composition. Earth System Science Data (2024).
3. Towards a better understanding of fine PM sources: Online and offline datasets combination in a single PMF. Environment International (2023).
4. Increased contribution of biomass burning to haze events in Shanghai since China’s clean air actions. Communications Earth & Environment (2023).
5. Air quality—climate forcing double whammy from domestic firelighters. npj Climate and Atmospheric Science (2023).