Lutz Ahrens, professor at the Swedish University of Agricultural Sciences ↗, has spent over two decades at the forefront of environmental chemistry, developing cutting-edge methods to detect and understand emerging pollutants like per- and polyfluoroalkyl substances (PFAS). Often labelled “forever chemicals” due to their extreme persistence, PFAS have become one of the most pressing global environmental challenges. In this interview, Ahrens reflects on the growing urgency to monitor and regulate these substances, the major scientific advances of the last decade, and how initiatives like PARC are contributing to better detection, risk assessment, and ultimately, safer environments across Europe.

What led you to specialise in PFAS and environmental process research?

I have been working with PFAS for over 20 years, and there is still so much we do not know about this group of chemicals. Often called "forever chemicals" due to their persistence in the environment, PFAS have become a pressing global issue – contaminating water supplies, soils, and even food chains. 

Looking back, what has changed most in this field over the last 10 years?

There is a growing urgency to monitor, regulate and mitigate PFAS pollution. Over the past decade, we’ve seen major developments: tricter regulations, improved detection methods including total PFAS analysis and advances in high-resolution mass spectrometry, PFAS-free alternative materials, remediation innovations, and rising public awareness.

What are the main sources of PFAS exposure in Europe? Do they vary by region?

PFAS exposure in Europe comes from several key sources, and the levels of contamination vary by region due to industrial activity, historical pollution, and local regulations. Key sources include industrial emissions, firefighting foams, food and packaging, consumer products, and waste facilities.  The distribution differs due to population density, historical industrial use, and gaps in monitoring data and source tracking. 

What about drinking water? Can we trust it’s safe in terms of PFAS?

That depends on location, regulations, and water treatment methods. In Europe and other industrial countries around the world, regulatory limits have been introduced to set maximum allowable PFAS concentrations in drinking water. However, contamination concerns remain, especially in areas near industrial sites, firefighting training facilities, and military bases.

What makes water safer or more at risk regarding PFAS?

Several factors: regulatory limits, existing water treatment systems (e.g. activated carbon, ion exchange, and nanofiltration/reverse osmosis), existing monitoring, transparency, and of course, regional pollution history all play a role.

Are there specific PFAS compounds causing more concern right now?

Yes, several PFAS compounds are currently raising significant concern due to their persistence, bioaccumulation, and potential health risks, particularly perfluorooctanoate (PFOA) and perfluorooctane sulfonate (PFOS). However, these substances have now been heavily restricted due to their environmental and health impacts. Additionally, (ultra-)short-chain PFAS, introduced as alternatives to long-chain PFAS, have gained increased attention due to their inclusion in total PFAS regulations and their potential risks to both the environment and human health.

We’re not just talking about a few chemicals, are we?

Not at all. Recently, the focus has shifted to alternative PFAS, with estimates suggesting that over 10,000 PFAS compounds are used in industrial and consumer products. However, the majority of these compounds have not been adequately assessed for persistence, bioaccumulation, or toxicity, leading to high uncertainty regarding their environmental and health impacts. Given these concerns, the comprehensive ban of all PFAS based on the essential use concept is urgently needed.

What health effects are associated with long-term PFAS exposure?

Long-term exposure to PFAS has been linked to various health risks, as these chemicals can accumulate in the body over time. While I am not a toxicologist, research suggests associations between PFAS exposure and several adverse effects, including increased cholesterol levels, liver damage, immune system suppression ( leading to lower antibody responses to vaccines), hormonal disruptions (including effects on thyroid function), pregnancy complications (e.g. pregnancy-induced hypertension and preeclampsia), reduced birth weight, and kidney and testicular cancer.

How is PARC contributing to the understanding or management of PFAS?

PARC plays a crucial role in advancing the understanding and management of PFAS by supporting chemical risk assessment and regulatory decision-making across Europe. It contributes through enhanced monitoring and risk assessment, innovative analytical methods, human biomonitoring, support for regulatory frameworks by providing scientific data and expertise, collaboration and knowledge sharing. PARC brings together ministries, public health agencies, research institutions, industry and academia to create a cross-disciplinary network, ensuring that PFAS research is effectively integrated into risk assessment and management strategies.

Can you specify the kind of data or methods that are being developed regarding PFAS to support policy decisions?

Data-driven methods and analytical approaches are being developed to improve risk assessment, environmental monitoring, and regulatory enforcement for PFAS contamination. 

Can you give an example of the tools or data PARC is working on to support regulation?

Key efforts include predictive models that estimate PFAS properties like solubility, persistence, and mobility, helping policymakers assess environmental and health risks. Researchers are refining validated analytical methods to enhance detection, quantification, and monitoring, ensuring more consistent regulation. Human biomonitoring studies track PFAS exposure over time, establishing reference values for policy decisions. Chemical fate modeling predicts how PFAS moves through air, water, and soil, guiding pollution prevention and remediation efforts. By integrating these tools, policymakers can make more informed decisions to strengthen PFAS regulations and protect public health.

Several European countries are pushing for group bans on PFAS. Do you see that as an effective approach?

Absolutely. I believe the proposed group ban on PFAS is the most effective way to reduce environmental contamination and health risks. Over the past two decades, it has become evident that banning individual PFAS compounds is insufficient, as they are frequently replaced with alternative PFAS that possess similar physicochemical properties and health risks. To address this issue, a broad restriction proposal under REACH has been submitted by Germany, the Netherlands, Denmark, Sweden, and Norway, aiming to limit the manufacture, use, and marketing of approximately 10,000 PFAS compounds.

Does PARC support this group approach?

PARC can play a crucial role in supporting this group approach by providing scientific evidence, regulatory guidance, and risk assessment tools to help policymakers make informed decisions. Additionally, PARC can encourage industries to transition to PFAS-free materials, thereby reducing reliance on harmful chemicals through the promotion of safer alternatives and Safe and Sustainable by Design (SSbD) initiatives.

From your perspective, what changes in industrial practices or waste management would have the biggest impact?

Reducing environmental PFAS loads requires significant changes in industrial practices and waste management. Some of the most effective strategies include eliminating PFAS in manufacturing, improving waste treatment, stricter regulations and monitoring, safer disposal methods, and developing PFAS-free alternatives using the SSbD framework.

What are PARC’s next priorities on PFAS? How do you see your role as a chemical leader?

PARC's next phase of research and policy action on PFAS focuses on advancing chemical risk assessment, regulatory frameworks, and sustainable solutions to mitigate PFAS contamination. As a chemical leader, my role is to facilitate activities including developing improved methods for hazard identification and chemical characterisation, particularly for PFAS mixtures, enhancing human biomonitoring, strengthening regulatory risk assessment by supporting evidence-based policymaking and aligning with the EU’s Chemicals Strategy for Sustainability,  promoting SSbD approaches, expanding cross-disciplinary collaboration, and informed decision-making, support scientific innovation, and ensure that PFAS research translates into actionable policies. By fostering collaboration and advocating for sustainable chemical management, I aim to contribute to a safer, more transparent regulatory landscape.