NEWS Many of our household products contain highly fluorinated chemicals, PFAS, compounds that are water and grease repellent. A new study by researchers at the Industrial Doctoral School at Umeå University in collaboration with Umeå Energi shows that when these products end up in household waste, there is a risk of PFAS ending up in our environment.
Sofie Björklund, PhD at the Department of Chemistry and the Industrial Doctoral School.
ImageMattias Petterssom, Foto: Mattias PetterssonHighly fluorinated chemicals, known as PFAS, are a large group of thousands of chemicals found in a variety of products, from stain-repellent rugs, grease-repellent food packaging and water-repellent leisure clothing, from ski wax and firefighting foam. In addition to being grease and water-repellent, PFAS are very stable and won’t break down in the environment, which is why they are sometimes called “forever chemicals”.
Over the past decade, Sweden has seen a number of reports of contaminated drinking water linked to PFAS in firefighting foam. Many PFAS are toxic and have been linked to elevated levels of cholesterol. They are also suspected of causing reduced birth weight in children and adverse effects on the immune system.
Used products containing PFAS end up in our waste sooner or later, and it is a well-known fact that PFAS are commonly found in landfills. In Sweden, however, you are not allowed to dispose combustible waste. This is instead more commonly incinerated for energy recycling.
Researchers in a project at Umeå University are currently investigating what happens to PFAS in our waste when it is incinerated. As the need for energy and district heating varies during the year, the waste is often stored near incineration plants to cover the need during cold winters.
To investigate the extent of PFAS leaked from the stored waste, the researchers collected samples of stormwater from the waste storage over a six month period in 2019. The stormwater was then tested for approximately 30 common PFAS. As there are thousands of PFAS on the market, the group also tested for extractable organic fluoride, which shows the total amount of fluorinated chemicals in the samples. The levels of extractable organic fluoride were found to be 7-8 times higher than levels explained by the most common PFAS.
“Combining these analyses can be compared to, not only looking at the part of an iceberg that protrudes above the surface, but also mapping the unseen part underneath”, says Sofie Björklund, PhD student at the Department of Chemistry and the Industrial Doctoral School at Umeå University, and one of the researchers behind the study.
She continues:
“Of the most common PFAS, we found the same types and concentrations as found in leachate from landfills. Although the emissions of PFAS from individual plants are not alarmingly high, there are a great amount of different sources of emissions. It is a situation that is difficult to manage and it is slowly becoming worse and worse.
The project was initiated by Umeå Energi, who were looking to gain knowledge on the impact of PFAS in their operations.
“The reports on contaminated drinking water has made the industry more aware of the issues surrounding PFAS. We know that PFAS are present in the waste arriving at our plants, but we don’t know much about how they behave when the waste is incinerated, and currently there are no guidelines to follow. So by co-financing and participating in this project, Umeå Energi wants to help spread knowledge on how PFAS behave in an incineration plant, and find measures to ensure that the environmental impact is as small as possible”, says Åsa Benckert, Environmental Engineer at Umeå Energi.
The project group is still investigating what happens to PFAS when the waste is incinerated. And there are many questions that need answers.
“We don’t know whether they degrade completely or partially, what compounds are formed as they degrade, and how the degraded compounds can get into the environment. It is important to realise that once PFAS get into the environment, they are very difficult to get rid of, and because PFAS are used in a multitude of products, it is difficult to get an overview of the total emissions and their effect”, says Sofie Björklund.
Sofie Björklund is currently conducting her PhD studies in a collaborative project between Umeå University and Umeå Energi.
Sofie Björklund, Eva Weidemann, Leo W. Yeung, Stina Jansson: Occurrence of per- and polyfluoroalkyl substances and unidentified organofluorine in leachate from waste-to-energy stockpile - A case study. Chemosphere, Volume 278, 2021. ISSN 0045-6535.
https://doi.org/10.1016/j.chemosphere.2021.130380
IDS is an inter-faculty research school that is based on collaboration between Umeå University and an organisation or a company. IDS aims to promote collaboration in order to strengthen research and development, increase the doctoral students’ employability, independence and innovative capacity, and increase knowledge and innovation in society.
www.umu.se/en/industrialdoctoralschool
Dåva Kraftvärmeverk. The project was initiated by Umeå Energi, who were looking to gain knowledge on the impact of PFAS in their operations.
ImageJohan Gunséus, Johan Gunséus/Synk