Per- and polyfluorinated alkyl substances (PFAS), also known as “forever chemicals” due to their persistence in the environment, can pollute the air and water sources, and have been linked to various health problems such as cancer. Previously it was believed that PFAS from the land could be washed into the ocean and ultimately be diluted over time, but further research has shown that these chemicals could be transported through the sea and back into the air. A recent study by researchers at Stockholm University further proves this sea-to-air transport phenomenon through liquid chromatography-tandem mass spectrometry analysis of air samples collected from coastal areas in Norway.
The researchers collected air samples between 2018 and 2020 using a high-volume active air sampler and quartz fiber filters. A portion of each sample processed and analyzed for perfluoroalkyl acids (PFAAs) using an ultraperformance liquid chromatography (UPLC) and tandem mass spectrometry (MS/MS) system, and the remaining portions were analyzed for the presence of sodium (Na+) and magnesium (Mg2+) ions through inductively coupled plasma-atomic emission spectrometry (ICP-AES). These ions served as markers for sea spray aerosol particles in order to determine whether there was a correlation between sea spray and PFAAs levels in the samples.
Through statistical analysis, the researchers identified a positive correlation between sea spray markers and PFAS levels, with perfluorooctanoic acid (PFOA) having the strongest correlation with Na+ out of the PFAAs that were tested. This data suggests that when PFAS enter the ocean, they can “boomerang” back to shore through waves and be carried into the air along with the sea spray aerosols, the researchers said. This study was published in Environmental Science & Technology.
“It is possible that atmospherically deposited PFAS could contaminate coastal drinking water sources for the foreseeable future,” said Ian Cousins, who co-authored the study. “Our study gives a new dimension to the meaning of the term forever chemicals. Even the PFAS we thought would be lost at the sea boomerang back for us to be exposed all over again.”
The research team collaborated with the Norwegian Institute of Air Research to conduct the long-term air sampling for the study, said lead author Bo Sha. The research was funded by the Swedish Research Council and FORMAS, a government research council for sustainable development.
Photo: An air sampling station in Andøya, Norway, was set up for the collection of field samples. Credit: Norwegian Institute of Air Research