PFAS found in drinking water from around the world

Scientists from the University of Birmingham, Southern University of Science and Technology and Hainan University have discovered toxic ‘forever chemicals’ present in samples of tap and bottled water sourced from 15 countries around the world.

Perfluoroalkyl substances (PFAS) are used widely in both industrial and consumer products due to their water- and stain-repellent properties. While some have been banned by government regulation, others are still widely used and their toxic effects not yet been fully investigated. They can however enter the body in various ways and have been linked to adverse health effects including a lowered immune response to vaccination, impaired liver function, decreased birth weight and increased risk of some cancers.

The researchers purchased 112 bottled water samples from local shops and online supermarkets in the UK and China, including 89 still and 23 sparkling waters in either plastic or glass bottles; the samples covered 87 brands with water sources originating from 15 countries in Asia, Europe, North America and Oceania. They also collected 41 tap water samples from homes in Birmingham and the nearby cities of Worcester, Coventry and Derby, provided by two suppliers — South Staffordshire Water and Seven Trent Water — with a further 14 tap water samples collected from homes in Shenzhen. Their results, published in ACS ES&T Water, revealed 10 ‘target’ PFAS in water available for consumption.

Bottled water from various countries showed varying levels of PFAS, with natural mineral water containing higher concentrations than purified water, but the concentrations were generally below health advisory levels set by regulatory agencies. Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) were detected in over 99% of samples of bottled water. The researchers observed no significant difference in target PFAS concentrations between glass and plastic or still and sparkling bottled water.

There were meanwhile significant differences in PFAS concentrations between tap water samples from Birmingham and Shenzhen, with Chinese tap water found to have higher concentrations of PFAS. Indeed, average PFOS concentrations in Shenzhen tap water samples exceeded the maximum contaminant level (MCL) of 4 ng/L newly promulgated by the US Environmental Protection Agency in 2024.

The good news is, the study demonstrated that measures such as boiling and/or activated carbon filtration — typically using a ‘jug’ water filter — can substantially reduce PFAS concentrations in drinking water, with removal rates ranging from 50% to 90% depending on the PFAS and treatment type.

“While current PFAS levels in most water samples are not a major health concern, ongoing monitoring and regulation are crucial to protect public health,” said study co-author Professor Stuart Harrad, from the University of Birmingham. “We provide valuable data on the presence of PFAS in drinking water alongside practical solutions to mitigate consumer exposure via drinking water. This is a significant step towards ensuring safer drinking water.”

“Increased awareness about the presence of PFAS in both tap and bottled water can lead to more informed choices by consumers, encouraging the use of water purification methods,” added co-author Professor Yi Zheng, from Southern University of Science and Technology.

“Our findings also suggest that the potential health risks of PFAS in drinking water may be influenced by lifestyle and economic conditions, highlighting the need for future research to further explore these factors from a socio-economic perspective.”

Image credit: iStock.com/Yurii Yarema