• Per- and polyfluoroalkyl substances (PFAS) chemicals have been detected in human brains, with the impacts of individual PFAS requiring further research.
• PFAS are a group of manmade chemicals that have been used in wide-ranging products due to their water and oil repellent properties, as well as resistance to high temperatures
• PFAS chemicals are extensively detected in the blood of people living in developed countries, but few studies have assessed the presence of PFAS on brain tissues

PFAS chemicals have been used in many useful products, but now their presence has been detected in brain tissues and researchers are working to understand the impact of individual PFAS.

Researchers from the Sydney Brain Bank at NeuRA, the Queensland Alliance for Environmental Health Sciences (QAEHS) at The University of Queensland, and the University of NSW School of Biomedical Sciences have found the number of carbons is a critical parameter for the accumulation of PFAS substances in the human brain.

“PFAS chemicals have been used in many products from food packaging and cookware to firefighting foam and furniture due to their useful qualities like water repellence and resistance to high temperature,” Director of the Sydney Brain Bank at NeuRA, Dr Claire Shepherd said.

“Humans have been exposed to PFAS in different ways, including drinking water, consumption of contaminated food, indoor dust ingestion or inhalation and use of PFAS-contaminated products. In developed countries, it’s now difficult to find people whose blood samples don’t have PFAS has measurable levels.

“This research analysed different PFAS chemicals and evaluated concentrations in paired post-mortem human brain and serum samples to investigate brain-to-serum concentration ratios.”

The potential health effects of PFAS have been widely raised and noted as including conditions such as immunosuppression in early childhood, thyroid diseases, liver damage, testicular cancer and more. There has also been reported associations between exposure and neuro-cognitive function.

“After PFAS enter the human body, they are distributed by the bloodstream and accumulate in the liver, kidney and spleen and they have also been detected in human brain samples,” Dr Shepherd said.

“This study was important to enhance our understanding of PFAS accumulation in the brain, which will help us evaluate potential health effects, including those related to neurodegenerative diseases.

“Results showed the total number of carbons of the individual PFAS is a key factor in determining the brain-to-blood concentration rations. We need to better understand individual PFAS, as their properties can influence how they behave in the human brain.”

The study was published in Environmental Science and Technology and can be read here.