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Forever chemicals are easily absorbed through skin

An alarming new study has revealed that 17 common types of synthetic “forever chemicals” can be easily absorbed through human skin. 

This research proves for the first time that a wide range of PFAS (perfluoroalkyl substances) – chemicals that do not break down in nature – can permeate the skin barrier and reach the bloodstream.

Widespread use of forever chemicals 

PFAS are widely used in industries and consumer products, including school uniforms and personal care items, for their water and stain repellent properties. 

While some substances have been banned by government regulations, others remain in use, and their toxic effects have not been fully explored.

Former chemicals can breach the skin barrier 

Previously, it was believed that forever chemicals could not breach the skin barrier. However, recent studies have linked the use of personal care products to PFAS concentrations in human blood and breast milk. 

This new study is the most comprehensive assessment of PFAS absorption into human skin to date, confirming that most of these chemicals can enter the body through this route.

Study lead author Dr. Oddný Ragnarsdóttir conducted the research while studying for her PhD at the University of Birmingham.

“The ability of these chemicals to be absorbed through skin has previously been dismissed because the molecules are ionized. The electrical charge that gives them the ability to repel water and stains was thought to also make them incapable of crossing the skin membrane,” noted Dr. Ragnarsdóttir.

“Our research shows that this theory does not always hold true and that, in fact, uptake through the skin could be a significant source of exposure to these harmful chemicals.”

PFAS skin absorption rates

The researchers examined 17 different types of forever chemicals, focusing on those most widely used and studied for their toxic effects. These compounds correspond to chemicals regulated by the EU’s Drinking Water Directive. 

The team used 3D human skin equivalent models – multilayered laboratory-grown tissues that mimic normal human skin – to measure absorption rates.

Skin absorbs some PFAS more than others

Of the 17 PFAS tested, 15 showed substantial dermal absorption, with at least 5% of the exposure dose being absorbed. 

The most regulated PFAS, perfluorooctanoic acid (PFOA), showed a 13.5% absorption rate into the bloodstream, with an additional 38% of the dose retained within the skin for potential longer-term uptake.

The researchers found that absorption levels correlated with the length of the carbon chain in the molecules. Compounds with shorter chains, which were introduced to replace longer-chain PFAS like PFOA, were more easily absorbed. 

For example, perfluoropentanoic acid was absorbed at a rate four times higher than PFOA, at 59 percent.

Skin exposure to forever chemicals 

“Our study provides first insight into the significance of the dermal route as a pathway of exposure to a wide range of forever chemicals,” said co-author Dr. Mohamed Abdallah. 

“Given the large number of existing PFAS, it is important that future studies aim to assess the risk of broad ranges of these toxic chemicals, rather than focusing on one chemical at a time.”

Broader implications of the research 

“This study helps us to understand how important exposure to these chemicals via the skin might be and also which chemical structures might be most easily absorbed,” said study co-author Professor Stuart Harrad.

“This is important because we see a shift in industry towards chemicals with shorter chain lengths because these are believed to be less toxic – however, the trade-off might be that we absorb more of them, so we need to know more about the risks involved.”

Potential health impacts of forever chemicals

PFAS, or forever chemicals, have been associated with several potential human health impacts. Exposure to these chemicals has been linked to a variety of adverse health effects.

Weakened immunity

PFAS can weaken the immune system, reducing the body’s ability to fight infections and potentially lowering the effectiveness of vaccines.

Liver damage

PFAS exposure can lead to liver damage, as these chemicals can accumulate in the liver, causing changes in liver function and contributing to diseases like non-alcoholic fatty liver disease.

Developmental issues

Exposure to PFAS, especially during pregnancy, can result in developmental problems in infants and children, such as lower birth weights, delayed puberty, and potential impacts on growth and learning.

Cancer risk

Some studies have suggested a link between PFAS exposure and an increased risk of certain cancers, including kidney and testicular cancer.

Hormonal disruptions 

PFAS can interfere with hormone production and regulation, leading to issues such as thyroid disease and reproductive problems.

Elevated cholesterol  

Elevated cholesterol levels have been observed in individuals exposed to PFAS, which can increase the risk of cardiovascular diseases.

Kidney function

There is evidence that PFAS can impact kidney function, potentially leading to chronic kidney disease.

Given the persistent nature of PFAS in the environment and the body, these health impacts underscore the importance of ongoing research and regulation to mitigate exposure and protect public health.

Common products containing forever chemicals

Some of the most common products containing PFAS include non-stick cookware, such as Teflon-coated pans, which use PFAS to create a non-stick surface. 

Water-resistant and stain-repellent fabrics, including outdoor gear, rain jackets, and some carpets, often contain these chemicals. 

PFAS are used in food packaging materials, like microwave popcorn bags and fast-food wrappers, to prevent grease from seeping through. 

Personal care products, such as some cosmetics, lotions, and shampoos, may contain PFAS to enhance their water and smudge resistance. Forever chemicals have even been found in many soft contact lenses in the United States. 

PFAS are also present in some cleaning products, paints, and coatings, providing durability and resistance to stains and corrosion. 

Despite increased regulation and awareness, these chemicals remain widespread due to their long-lasting and versatile properties.

The University of Birmingham study is published in the journal Environment International


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