Per- and polyfluoroalkyl substances (PFAS), the so-called “forever chemicals”, have become one of the most persistent and complex contaminants in modern water systems.
A new global study published in Water & Ecology has mapped 20 years of scientific progress in understanding PFAS in drinking water, revealing how international research priorities and governance frameworks have evolved since the early 2000s.
Led by Dr Chong Liu and colleagues from several institutions, the study examined more than 1,200 publications indexed in the Web of Science between 2003 and 2023. It identified a sustained rise in PFAS-focused research within environmental science and engineering, driven by growing public health concerns and regulatory action.
According to Liu, the findings demonstrate that while awareness has grown dramatically, scientific and policy responses remain fragmented.
“Research on PFAS in drinking water must shift from isolated studies to coordinated, system-level action,” he said.
Evolving understanding of PFAS behaviour and risk
The study integrates pollution pathways, monitoring practices, and treatment technologies into a single analytical framework. It shows how research priorities have shifted from identifying contamination sources to addressing the full life cycle of PFAS, from detection and transport to removal and waste management.
PFAS compounds enter water systems through industrial effluent, landfill leachate, atmospheric deposition, and surface runoff. Their strong carbon–fluorine bonds make them resistant to degradation, allowing them to persist in groundwater and surface water for decades. The study highlights that short-chain and ether-based PFAS, which are replacing older long-chain formulations, pose new monitoring and treatment challenges due to their mobility and stability.
Traditional detection techniques, such as liquid chromatography–tandem mass spectrometry, remain the analytical benchmark, but the study notes growing attention to portable, high-selectivity sensors capable of field deployment. These tools could bridge the gap between laboratory precision and on-site monitoring, improving early detection across distributed water networks.
Towards integrated treatment and management approaches
Treatment remains the most significant technical bottleneck. The authors examined how current methods, including activated carbon, ion exchange, membrane filtration, and advanced oxidation, perform against different PFAS structures. Each approach presents trade-offs between cost, selectivity, and waste generation.
Liu said progress requires a new generation of combined or sequential systems. “We should advance multistage ‘intercept-and-destroy’ treatment trains and improve the safe management of concentrated residuals,” he explained. The study advocates for integrating treatment performance data with regulatory benchmarks to support cost-effective adoption by utilities and industries.
This coordinated approach would align laboratory research with operational practice, ensuring that innovations reach implementation more quickly and with clearer performance and safety metrics.
Governance and the path to PFAS-free water
Beyond technology, the analysis provides a global perspective on how policy and governance have adapted to PFAS contamination. It highlights three broad phases in research evolution: the establishment of a theoretical base in the early 2000s, steady growth during the 2010s, and an accelerated surge after 2017, coinciding with new U.S. EPA advisories and European Union restrictions.
The authors argue that regulatory progress must now keep pace with scientific advances. While several jurisdictions have introduced limits on PFAS concentrations in drinking water, inconsistency in analytical standards and allowable thresholds continues to hinder coordinated action.
The study proposes a research-to-policy roadmap that emphasises international data sharing, harmonised monitoring protocols, and the development of global cost–performance benchmarks for treatment. These measures could help countries set realistic goals for achieving PFAS-free water while protecting vulnerable populations.
A growing scientific and policy movement
The authors conclude that the fight against PFAS contamination is entering a new phase of collaboration and accountability. Scientific focus is moving from characterising individual compounds to addressing systemic behaviours across complex water systems.
Liu said the study provides a framework for uniting science and governance.
“By linking laboratory analytics with real-time sensor networks and standardised data systems, we can close monitoring gaps and better manage PFAS risk. Translating that knowledge into effective policy is the next frontier.”