Health Citizens – European Research Institute

PFAS, Environment & Brain

PFAS: The “Forever Chemicals” Threatening Our Health and Environment

Per- and polyfluoroalkyl substances (PFAS), also known as forever chemicals, compose a broad range of anthropogenic chemicals extensively used for their water, grease, and stain-resistant properties, which derive from their strong carbon-fluorine bonds. Nowadays, they are commonly used in food containers, non-stick cookware, medical devices, paints, water-resistant clothing, personal protective equipment, fire-fighting foams, and even ski waxes, among others. However, their incredible resilience properties also means that they persist in the environment for decades, accumulating in soil after disposal, and leaching into groundwater, moving through rivers and streams1,2. 

Beyond their widespread use and persistence, PFAS are now recognised as a global environmental contaminant, capable of long-range transport through air, water, and sediments. Their physical and chemical properties strongly influence their environmental fate and facilitate their accumulation in remote regions, including the Arctic and the North Atlantic Ocean1,2,3. Due to their high persistence, bioaccumulative nature, toxicity, and transport potential,  several efforts have been made by the European Union (EU) to restrict the use of PFAS as a group4,5. 

Climate change is increasingly recognised as a key factor amplifying PFAS dispersion across ecosystems. Although PFAS are generally considered non-volatile, some short-chain PFAS precursors can enter the atmosphere under high-temperature conditions. Once airborne, they may travel long distances before redepositing through rainfall, a process known as atmospheric deposition. Extreme weather events such as flooding and stormwater runoff, rising temperatures, sea-level rise, saltwater intrusion, and changes in soil chemistry and hydrology, can all further intensify PFAS mobilisation and human exposure, demonstrating that PFAS pollution is no longer a local issue, but a planetary one, shaped by climate-driven transport mechanisms6.

From environmental exposure to the brain

Due to their widespread environmental presence, human exposure to PFAS is now nearly universal. It is currently known that most individuals have detectable levels of PFAS in their blood, with exposure occurring primarily through contaminated food, drinking water, and everyday consumer products7. Although regulatory actions have reduced the use of long-chain PFAS such as perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA), two of the most prominent PFAS, these compounds have largely been replaced by short-chain alternatives that are less studied but may pose comparable risks8.

PFAS are highly lipophilic and bind strongly to albumin and other plasma proteins, facilitating their transport throughout the body and across the blood–brain barrier (BBB)8. Studies in rats have detected PFAS, including PFOA and PFOS, in brain regions such as the brainstem, hippocampus, and hypothalamus, where they may disrupt neurotransmission, neuroimmune signalling, and tight junction integrity. Furthermore, while PFAS-induced oxidative stress and reactive oxygen species (ROS) production may further compromise BBB integrity and trigger neuroinflammatory responses, increased BBB permeability may allow additional neurotoxic substances to enter the central nervous system, amplifying neurological risk7,8.

Accumulating evidence also indicates that PFAS exposure can affect dopaminergic neurons, impairing both early and late stages of neurodevelopment. Disruptions in dopamine pathways have been associated with altered neurochemical, neurophysiological, and behavioural outcomes, including symptoms linked to attention-deficit/hyperactivity disorder (ADHD)8. However, while the physical health impacts of PFAS, such as cancer, immune dysfunction, and reproductive harm, are well documented, their effects on mental health remain comparatively underexplored. Emerging research suggests potential links between PFAS exposure and anxiety, depression, cognitive impairment, and neurodegenerative diseases, but relatively few studies have systematically examined these outcomes. Significant gaps also remain regarding cumulative exposures, PFAS mixtures, and effects on specific brain regions such as the nigrostriatal system8.

Critically, much of the existing literature does not disaggregate mental health outcomes by race or socioeconomic status. Environmental contamination, when combined with systemic inequities, may intensify mental health burdens in already vulnerable communities. As climate change accelerates PFAS redistribution and exposure, understanding these intersecting environmental and social determinants becomes increasingly urgent8.

Together, PFAS contamination, climate change, and mental health represent a deeply interconnected challenge. While regulatory progress has been made, several uncertainties remain regarding long-term environmental behaviour, neurological impacts, and population-level mental health consequences. Addressing these gaps will require interdisciplinary research, stronger environmental governance, and policies that explicitly account for climate-driven chemical redistribution and social vulnerability.

References:

  1. Mahmoudnia, A., Mehrdadi, N., Baghdadi, M., Moussavi, G. (2022). Change in global PFAS cycling as a response of permafrost degradation to climate change. Journal of Hazardous Materials Advances Volume 5, 100039. doi:  10.1016/j.hazadv.2021.100039.
  2. Alazaiza, M.Y.D., Alzghoul, T.M., Ramu, M.B., Amr, S.S.A., Abushammala, M.F.M. (2025). PFAS contamination and mitigation: A comprehensive analysis of research trends and global contributions. Case Studies in Chemical and Environmental Engineering, Volume 11, 101127. doi: 10.1016/j.cscee.2025.101127.
  3. Ashani, A., Vilhelmsson, O.Þ., Karsten, U., Grossart, H.P., Sigurbjörnsdóttir, A., Rolfsson, Ó., Joerss H., Scholz, B. (2025). Per- and polyfluoroalkyl substances (PFAS) in the cryosphere – occurrence, organismic accumulation, ecotoxicological impacts, transformation, and management strategies. Frontiers in Environmental Science, Volume 13. doi:10.3389/fenvs.2025.1559941. 
  4. PFAS polymers in focus: supporting Europe’s zero pollution, low-carbon and circular economy ambitions (2025). European Environment Agency Briefing 04/2025.  doi: 10.2800/0087006.
  5. Abunada, Z., Alazaiza, M.Y.D., Bashir, M.J.K. (2020). An Overview of Per- and Polyfluoroalkyl Substances (PFAS) in the Environment: Source, Fate, Risk and Regulations. Water, 12(12), 3590. doi: 10.3390/w12123590.
  6. Shannon (2025, Apr 1). How climate change influences the spread of pfas in water sources. PFAS-Water. https://www.pfas-water.co.uk/how-climate-change-influences-the-spread-of-pfas-in-water-sources/
  7. Piekarski, D.J., Diaz, K.R., McNerney, M.W. (2020). Perfluoroalkyl chemicals in neurological health and disease: Human concerns and animal models. Neurotoxicology. 77:155-168. doi: 10.1016/j.neuro.2020.01.001.
  8. Sukhram SD, Kim J, Musovic S, Anidugbe A, Corte E, Ahsan T, Rofail S, Mesquita N, Padilla M. PFAS Exposure, Mental Health, and Environmental Justice in the United States: Impacts on Marginalized Communities. Int J Environ Res Public Health. 2025 Jul 15;22(7):1116. doi: 10.3390/ijerph22071116.