Chemical Contamination in Humans and Links to Neurodegenerative Diseases

This project aims to advance our understanding of the links between environmental chemical exposures and neurodegenerative diseases.

Despite the protective mechanism of the Blood-Brain Barrier (BBB), designed to shield the brain from harmful substances, emerging evidence suggests that certain chemicals may breach this barrier and enter the brain. Our research aims to determine whether chemicals are indeed present in the human brain as well as identify the key chemical properties that influence their ability to cross from the bloodstream into the brain.

Another key aim is to explore the potential role of chemical exposures as a cause of neurodegenerative diseases, specifically Parkinson’s Disease (PD) and Motor Neurone Disease (MND). While the exact causes of PD and MND remain unclear, a growing body of evidence suggests that chemical exposure may significantly contribute to their onset. Our research will examine areas with high concentrations of PD and MND cases and explore potential factors that could explain the increased prevalence of these diseases in those areas.

This project will shed light on the potential risks posed by environmental chemical exposures to human brain health. This project is supported by the Neuroscience Research Australia (NeuRA) and the Minderoo Foundation.

Outcomes

The preliminary data on PFAS concentrations in matched brain and blood samples indicate that individual PFAS compounds exhibit a varying ability to cross the blood-brain barrier. Moreover, it has been suggested that the chemicals' ability to dissolve in fats, oils, and lipids (lipophilicity) may play a crucial role in determining the extent to which each PFAS compound penetrates the brain. While factors such as molecular weight and protein binding affinity can influence BBB permeability for substances, our findings suggest that, for PFAS, lipophilicity will be a critical consideration in assessing risks to the brain.

Research Outputs

Suzuki, M., Nilsson, S., Shepherd, C.E., Zammit, I., Suryana, E., Mueller, N., Halliday, G., Wang, X., Symeonides, C., Dunlop, S. and Mueller, J.F., 2025. Number of Carbons Is a Critical Parameter for Accumulation of Per-and Polyfluoroalkyl Substances in the Human Brain. Environmental Science & Technology.

Media

• 27 February 2025: Research and the Number of Carbons Is a Critical Parameter for Accumulation of Per- and Polyfluoroalkyl Substances in the Human Brain publication were highlighted in the Sydney Morning Herald.
• 7 March 2025: Co-author Dr Claire Shepherd was interviewed by ABC Radio regarding the Number of Carbons Is a Critical Parameter for Accumulation of Per- and Polyfluoroalkyl Substances in the Human Brain publication.