Flame retardants are designed to save lives by reducing fire risks, but many of these chemicals are raising alarms due to their potential health dangers. Known as ‘forever chemicals,’ these compounds are notorious for their resistance to degradation and their tendency to accumulate in body tissues. Some have been linked to hormone disruption and cancer, though the full extent of their impact on humans is still under investigation.
The US Centers for Disease Control and Prevention (CDC) indicates that humans are often exposed to flame retardants by consuming contaminated food or inhaling contaminated air. With the growing prevalence of plastics in various products, such as foam padding and appliance casings, the decomposition into microplastics has become a new concern.
A recent study by researchers from Brunel University London and the University of Birmingham in the UK points to another possible exposure route: absorption through the skin. The team discovered that polybrominated diphenyl ethers (PBDEs), a class of flame retardants, can be absorbed through human skin and enter the bloodstream within 24 hours.
Using a 3D-printed model of human skin, the researchers showed that when skin comes into contact with microplastics containing PBDEs, the compounds can penetrate through, with sweatier skin absorbing more readily than dry skin.
This study suggests that the skin could be an overlooked pathway for PBDE exposure, potentially contributing to the body burden of these chemicals, which have been linked to cancer and endocrine disruption.
“We confirm for the first time that human exposure via skin contact with microplastics containing PBDEs contributes to the human body burdens of these toxic chemicals,” says lead author Ovokeroye Abafe, an environmental chemist and exposure scientist at Brunel University London.
PBDEs were widely used from the 1970s to reduce fire hazards in various consumer products. Though some have been banned due to health concerns, many are still in use. As plastic items degrade into microplastics, they can lodge in human bodies, leading to increased scrutiny over their health impacts.
The researchers used 3D-printed models of human skin composed of human keratinocytes, the primary cells in our epidermis, to study the absorption of PBDEs. They found that up to 8 percent of the exposure dose was absorbed, while less than 0.1 percent reached the bloodstream. Though this doesn’t necessarily imply immediate danger, it demonstrates that skin isn’t entirely impervious to these compounds.
Given the widespread use of PBDEs and their associated health risks, these findings call for urgent action to protect public health, Abafe says. Further research is needed to understand the broader implications and to explore other chemicals within microplastics that may also pose risks to human health.
“Unfortunately, there are myriads of toxic additive chemicals, ranging from plasticisers to stabilizers in microplastics, some of which are not regulated, that can potentially find their way into the human system,” Abafe warns.
The study was published in Environment International.
