New Study Reveals Wider Impact of Human-Made Air Pollution

A fresh global research report conducted at CERN has found new evidence of how anthropogenic organic aerosols (AOAs) are created, finding their influence to be greater than believed before. They are poisons composed of particles containing carbon and emitted by humans in the forms of transportation, industry, and domestic burning. They are very dangerous to the life of man and cause millions of deaths each year globally.

How Organic Aerosols are Formed
Historically, researchers had thought organic aerosols resulted from a single-step oxidation. Terpenes and isoprene, which are the emissions from plants in nature, have a quick reaction with oxygen to form solid air particles. The researchers discovered that the pollutants of human activities, however, occur in a multi-step process. Automobile exhaust and industrial flue gases like toluene and benzene go through sequential oxidation processes before they become particulate matter. This time lag in conversion results in AOAs not being a regional phenomenon but extend regionally thousands of miles wide to impact air quality. Revolutionary Research at CERN's CLOUD Chamber

Experiments were carried out in the world's cleanest atmospheric simulation laboratory, CERN's CLOUD (Cosmics Leaving Outdoor Droplets) chamber. Researchers replicated urban air pollution conditions and tracked how exhaust gases transformed into organic aerosols. Researchers could tightly control temperature and pressure in the chamber and quantify changes in real time. Researchers used sophisticated methods like mobility analysis and mass spectrometry to study particle formation.
Findings and Implications

The study proved that over 70% of AOAs are produced through multi-step oxidation, a process that occurs between six hours and two days. This is contrary to the belief that contaminants primarily develop close to their point of origin. Rather, they continue to linger in the atmosphere, chemical interactions leading to a strengthening of their impact across a wider area.
The research identifies the necessity of controlling not just direct emissions but also precursor gases which ultimately become hazardous particles. Existing pollution legislation addresses prevention of car, factory, and home emissions through particulate filters. This is not sufficient, however, since most of the hazardous particles only show up after prolonged chemical reactions in the air.

Better Air Pollution Predictions

The conclusions will enhance models of air quality such that one can be in a position to better predict concentrations of particulate matter. It may assist policymakers to formulate policies to help respond better to air pollution, safeguard the health of individuals, and bring to an end the long-lived effect of anthropogenic aerosols.

Conclusion

The research offers vital new information about the formation and dissemination of AOAs. By knowing their longer transformation process, researchers can enhance methods of controlling pollution and minimizing the adverse effects of air pollution. The research is calling for stricter controls on direct emissions and precursor gases such that overall air pollution is minimized and communities are safeguarded from its negative effects.

Source: Nature Geoscience (2025). DOI: 10.1038/s41561-025-01645-z