PFAS are man-made chemicals found in many products due to their heat and water resistance. They are found, for example, as compounds in non-stick cookware, waterproof clothing, fire-fighting foams, food packaging and cosmetics. They do not degrade in the environment and accumulate in living organisms, including humans, with carcinogenic effects. Due to their persistence, they are also called “forever pollutants”.
In this critical context, an important step forward has been taken by Sapienza University of Rome. Eduardo Di Marcantonio, a PhD student at the Department of Earth Sciences, under the supervision of professors Luigi Dallai and Massimo Marchesi, developed the first analytical method for the isotopic analysis of the main PFAS present in the environment.

Compared to chemical analyses, isotopic analyses do not merely reveal the presence and quantity of a compound, but also provide a value that may vary for the same compound depending on the chemical, physical or biological process that originated it. This type of analysis therefore makes it possible, in conditions of widespread pollution, to differentiate between different sources as well as dispersion in the environment.

After more than 300 experimental attempts, the research team developed a protocol that allows specific “isotopic signatures” to be obtained for PFAS from different industrial manufacturers. This characterisation makes it possible to distinguish the origins of the compounds, even in scenarios of widespread pollution – i.e. with multiple sources that cannot be precisely identified.

The study, published in the journal Science of The Total Environment, also showed significant isotopic differences between PFAS of different origins, paving the way for the identification of the sources of these “eternal contaminants” in the environment.

The method was developed at the Department of Earth Sciences, which in recent years has invested heavily in creating one of Europe's most advanced stable isotope laboratories, with the aim of putting research at the service of environmental monitoring and public health protection.

This new methodology, which provides the first source tracer for contaminants that are so dangerous to health and at the same time too little monitored, is part of a pilot project that was launched, in collaboration with the CNR, to analyse samples from the red zone of PFAS contamination in the province of Vicenza, northern Italy.

References: Eduardo Di Marcantonio, Orfan Shouakar-Stash, Massimo Marchesi, Luigi Dallai  “Compound-specific carbon isotope analysis of perfluorocarboxylic acids (PFCAs) by gas chromatography-isotope ratio mass spectrometry”, Science of The Total Environment (2025) – DOI https://doi.org/10.1016/j.scitotenv.2025.180564